Note: Descriptions are shown in the official language in which they were submitted.
CA 02313875 2000-07-14
A FILLED DETERGENT TABLET
Field of the Invention
This invention relates to detergent tablets, to processes for their
production and to their use.
Background of the Invention
Detergent tablets are widely described in the prior art literature and,
being easy to dose, are enjoying increasing popularity among consumers.
Tabletted detergents have a number of advantages over powder-form
products. They are easier to dose and handle and, by virtue of their
compact structure, have advantages in regard to storage and
transportation. Accordingly, there is an extremely broad prior art on
detergent tablets which is also reflected in extensive patent literature. At a
very early stage, developers of tablet-form products came up with the idea
of releasing certain ingredients into the wash cycle under defined
conditions through differently composed parts or regions of the tablets in
order in this way to improve the outcome of the cleaning process. Besides
the coreljacket tablets and ringlcore tablets known for some time in the
pharmaceutical industry, multilayer tablets in particular have been
successfully used and are now available for many aspects of washing and
cleaning or hygiene. The optical differentiation of the products is also
becoming increasingly more important so that single-phase one-color
detergent tablets have largely been replaced by multiphase tablets. At
present, two-layer tablets with one white and one colored phase or with two
differently colored layers are available on the market. There are also bull's-
eye tablets, ring core tablets, jacketed tablets, etc. although they are of
secondary importance at present.
Multiphase lavatory cleaning tablets are described, for example, in
European patent application EP 0 055 100 (Jeyes Group). This document
discloses toilet cleaning blocks which comprise a shaped body of a slowly
dissolving cleaning composition in which a bleaching tablet is embedded.
CA 02313875 2000-07-14
2
The document in question also discloses various embodiments of
multiphase tablets. According to the teaching of EP 0 055 100, the tablets
are produced either by introducing a bleaching tablet into a mold and
coating the tablet with the cleaning composition or by casting part of the
cleaning composition into the mold, introducing the bleaching tablet and,
optionally, overcoating with more cleaning composition.
EP 481 547 (Unilever) describes multiphase detergent tablets which
are intended for use in dishwashing machines. These tablets are
coreljacket tablets and are produced by compressing the ingredients in
stages. First, a bleaching composition is compressed to a form a shaped
body which is introduced into a die half filled with a polymer composition
which is then filled with more polymer composition and compressed to form
a bleaching tablet with a polymer jacket. The procedure is then repeated
with an alkaline detergent composition so that a three-phase tablet is
obtained.
Another method of producing optically differentiated detergent
tablets is described in International patent applications WO 99106522, WO
99!27063 and WO 99127067 (Procter & Gamble). According to the
teachings of these documents, the cavity of a cavity tablet is filled with a
solidifying melt. Alternatively, the cavity is filled with a powder which is
secured therein by a coating layer. One factor common to all three
applications is that the region filling the cavity is not intended to be
compressed because pressure-sensitive ingredients are intended to be
protected in this way.
The method described in the prior art of preparing melts in which the
tablets are placed or which are cast into shaped bodies involves thermal
stressing of the ingredients in the melts. In addition, the precise dosage of
liquid or paste-form media and the subsequent cooling step involve
significant outlay on equipment which, depending on the composition of the
melt, is partly destroyed by shrinkage during cooling and by the resulting
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separation of the filling. The filling of cavities with powder-form
ingredients
- and the fixing of these powders by coating also involves outlay on
equipment and is attended by similar stability problems.
The conventional tabletting of multilayer tablets also has its limits in
the field of detergent tablets if one layer is intended to make up only a
small part of the tablet as a whole. If the layer thickness falls below a
certain value, the compression of a layer adhering to the rest of the tablet
becomes increasingly difficult.
Although the pressing of particulate compositions into cavities of
tablets solves the thermal stressing problem of these fillings, it can also
lead to a delay in the dissolution of this compressed portion which
necessitates the addition of dissolving accelerators if the accelerated
release of ingredients from this region is required. Liquid, gel-form or
paste-form media cannot be introduced either by casting or by tabletting
unless these media solidify in the course of the production process.
Now, the problem, addressed by the present invention was to
provide tablets in which both heat-sensitive and pressure-sensitive
ingredients could be introduced into demarcated regions which would not
be restricted in size in relation to the tablet as a whole. In addition,
optical
differentiation to conventional two-layer tablets would be achieved while, at
the same time, production of the tablets, even in large numbers, would
operate safely despite only minimal outlay on equipment without the tablets
having any disadvantages in regard to stability and without any risk of
dosage inaccuracies. In addition, accelerated release of the ingredients
from the demarcated region would be possible without any particular
modifications having to be made to the formulations used. The invention
set out to provide a form of incorporation which would be independent of
the aggregate state of the active substances or active-substance mixtures
to be introduced into the region so that even active substances not
compatible with conventional dissolving accelerators or disintegration aids
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would lend themselves to incorporation in and accelerated release from the
- region. Last but not least, liquids, gels and pastes would also lend
themselves to permanent incorporation without those states having to be
changed in any way pending use.
Summary of the Invention
It has now been found that the disadvantages mentioned above are
avoided if liquid, gel-form, paste-form or solid ingredients are introduced
into a cavity of a precompressed tablet and the cavity is then sealed off
with a film. In this way, the ingredients are protected against thermal or
compressive stressing and the problems stated above are solved.
The present invention relates to detergent tablets of compacted
particulate detergent, characterized in that the tablet comprises at least one
cavity of which the openings) islare closed by a film.
The cavity in the tablet produced in step a) may assume any shape.
It may extend throughout the tablet, i.e. may have an opening at the top
and bottom of the tablet, although it may also be a cavity which does not
extend throughout the tablet, i.e. a cavity of which the opening is only
visible on one side of the tablet.
The tablets according to the invention may assume any geometric
form, concave, convex, biconcave, biconvex, cubic, tetragonal,
orthorhombic, cylindrical, spherical, cylinder-segment-like, disk-shaped,
tetrahedral, dodecahedral, octahedral, conical, pyramidal, ellipsoidal,
pentagonal-, heptagonal- and hexagonal-prismatic and rhombohedral
forms being particularly preferred. Completely irregular bases, such as
arrow and animal shapes, trees, clouds etc. can also be produced. If the
tablets according to the invention have corners and edges, they are
preferably rounded off. As an additional optical differentiation, an
embodiment with rounded-off corners and bevelled ("chamfered") edges is
preferred.
The tablets according to the invention may of course also be
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produced as multiphase tablets. In the interests of process economy, two-
layered tablets have proved to be particularly effective.
The shape of the cavity can also be freely selected. In the interests
of process economy, holes which open on opposite sides of the tablets and
recesses which open on one side only have proved successful. In
preferred embodiments, the cavity is in the form of a hole opening on two
opposite sides of the tablet. The shape of this hole may be freely selected,
preferred tablets being characterized in that the hole has circular,
ellipsoidal, triangular, rectangular, square, pentagonal, hexagonal, hepta-
gonal or octagonal horizontal sections. The hole may also assume
completely irregular shapes, such as arrow or animal shapes, trees, clouds,
etc. As with the tablets, angular holes preferably have rounded-off corners
and edges or rounded-off corners and chamfered edges.
Detailed Description of the Invention
The geometric forms mentioned above may be combined as
required with one another. Thus, tablets with a rectangular or square base
and circular holes can be produced just as well as round tablets with
octagonal holes, the various combination possibilities being unlimited. In
the interests of process economy and consumer acceptance, particularly
preferred holed tablets are characterized in that the base of the tablet and
the cross-section of the hole have the same geometric form, for example
tablets with a square base and a centrally located square hole. Ring
tablets, i.e. circular tablets with a circular hole, are particularly
preferred.
If the above-mentioned principle of the hole open on two opposite
sides of the tablet is reduced to one opening, the result is a recess tablet.
Detergent tablets according to the invention in which the cavity assumes
the form of a recess are also preferred. As with the "hole tablets", the
tablets according to the invention in this embodiment, too, may assume any
geometric form, concave, convex, biconcave, biconvex, cubic, tetragonal,
orthorhombic, cylindrical, spherical, cylinder-segment-like, disk-shaped,
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tetrahedral, dodecahedral, octahedral, conical, pyramidal, ellipsoidal,
pentagonal-, heptagonal- and octagonal-prismatic and rhombohedral forms
being particularly preferred. The base of the tablet may even assume a
completely irregular shape, such as arrow or animal shapes, trees, clouds,
etc. If the tablet has corners and edges, they are preferably rounded-off.
As an additional optical differentiation, an embodiment with rounded-off
corners and chamfered ("bevelled") edges is preferred.
The shape of the recess may also be freely selected, tablets in
which at least one recess may assume a concave, convex, cubic,
tetragonal, orthorhombic, cylindrical, spherical, cylinder-segment-like, disk-
shaped, tetrahedral, dodecahedral, octahedral, conical, pyramidal, ellip-
soidal, pentagonal-, heptagonal- and hexagonal-prismatic and
rhombohedral form being preferred. The recess may also assume a totally
irregular shape, such as arrow or animal shapes, trees, clouds etc. As
with the tablets, recesses with rounded-off corners and edges or with
rounded-off corners and chamfered edges are preferred. The recess
shapes described in earlier German patent application DE 198 22 973.9
(Henkel KGaA), to which reference is expressly made here, are particularly
preferred.
The size of the recess or the hole by comparison with the tablet as a
whole is governed by the application envisaged for the tablets. The size of
the cavity can vary according to whether it is to be ~Iled with more active
substance sand whether a relatively small or relatively large quantity of
active substance is intended to be present. Irrespective of the intended
application, preferred detergent tablets are characterized in that the ratio
by
volume of tablet to cavity is 2:1 to 100:1, preferably 3:1 to 80:1, more
preferably 4:1 to 50:1 and most preferably 5:1 to 30:1. The ratio by volume
is calculated from the volume of the finished tablet according to the
invention, i.e. the tablet with the cavity closed by the film, and the volume
of
the cavity. The difference between the two volumes is the volume of the
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cavity tablet in which the cavity is not closed by film. In other words: if
the
tablet has, for example, an orthorhombic shape with side lengths of 2, 3
and 4 cm and has a cavity with a volume of 2 cm3, the volume of this "basic
tablet" is 22 cm3. The volume used to calculate the ratio is 24 cm3 because
the cavity is closed by a film so that, to the outside, the tablet is
orthorhombic with no cavity. Accordingly, in this example, the ratio
between the volumes is 12:1. With tablet:cavity volume ratios below 2:1,
which of course are also possible in accordance with the invention, the
instability of the walls can increase.
Similar observations may also be made on the contribution which
the tablet with the cavity ("basic tablet") or the opening area of the cavity
makes to the total surface area of the tablet. Here, preferred detergent
tablets are characterized in that the area of the openings) of the cavity(ies)
makes up 1 to 25%, preferably 2 to 20%, more preferably 3 to 15% and
most preferably 4 to 10% of the total surface area of the tablet. The total
surface area of the tablet again corresponds to the total surface area of the
tablet with the closed cavity, i.e. in the above example 52 cm2 irrespective
of the area of the cavity opening(s). Accordingly, in an exemplary tablet
such as this, the openings) of the cavity in preferred embodiments of the
invention haslhave an area of 0.52 to 13 cm2, preferably 1.04 to 10.4 cm2,
more preferably 1.56 to 7.8 cm2 and most preferably 2.08 to 5.2 cm2.
The cavity tablets according to the invention are characterized in
that the openings) of the cavity(ies) islare closed by film. In the context of
the present invention, the term "closed" is intended to mean that the film
which closes the opening of the cavity(ies) is firmly bonded to the tablet.
Accordingly, a pack into which the tablet is inserted does not satisfy the
"closing" criterion according to the invention.
The film which closes the openings) of the cavity(ies) is applied to
the surface of the tablet and is firmly bonded thereto, for example by
adhesive bonding, partial melting or by chemical reaction. The film may be
CA 02313875 2000-07-14
applied to all the surfaces of the tablet and may be firmly bonded thereto so
- that the film forms a coating over the tablet as a whole. However, preferred
detergent tablets are characterized in that the film does not surround the
entire tablet.
In the interests of process economy and the aesthetic impression,
the film is preferably applied to only those surfaces of the tablet where it
performs a function, i.e. the closing of cavities. Accordingly, detergent
tablets in which the film only covers those surfaces of the tablet in which
openings of the cavity(ies) are present are preferred.
The cavity-closing film may of course also be a laminate of several
films differing in their composition. Through different compositions of
individual film layers, the opening of the cavity can be opened at certain
times in the wash cycle, which is of advantage in particular when the closed
cavity contains other active substances.
Preferred film materials are the polymers known from the prior art.
Particularly preferred detergent tablets are characterized in that the film
consists of a polymer with a molecular weight of 5000 to 500,000 dalton,
preferably 7500 to 250,000 dalton and more preferably 10,000 to 100,000
dalton. With the media into which detergents are normally introduced in
mind, detergent tablets where the film consists of a water-soluble polymer
are particularly preferred.
These preferred polymers may be of synthetic or natural origin. If
polymers based on native or part-native raw materials are used as the film
material, preferred detergent tablets are characterized in that the film
material is selected from one or more substances from the group consisting
of carrageenan, guar, pectin, xanthan, cellulose and derivatives thereof,
starch and derivatives thereof and gelatine.
Carrageenan is an extract of North Atlantic red algae belonging to
the Florideae which is named after the Irish coastal town of Carragheen
and which is similar in composition to agar. The carrageenan precipitated
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9
from the hot water extract of the algae is a colorless to sand-colored
- powder with molecular weights of 100,000 to 800,000 and a sulfate content
of around 25% which dissolves very easily in warm water. Carrageenan
has three principal constituents. The gel-forming f fraction consists of D-
galactose-4-sulfate and 3,6-anhydro-a-D-galactose which are alternately
attached by glycosidic bonds in the 1,3- and 1,4-positions (by contrast agar
contains 3,6-anhydro-a-L-galactose). The non-gelling I-fraction is made up
of 1,3-glycosidically linked D-galactose-2-sulfate and 1,4-linked D-
galactose-2,6-Bisulfate residues and is readily soluble in cold water. The i-
carrageenan made up of D-galactose-4-sulfate in 1,3-linkage and 3,6-
anhydro-a-D-galactose-2-sulfate in 1,4-linkage is both water-soluble and
gel-forming. Other carrageenan types are also denoted by Greek letters:
a, ~3, y, ~, v, ~, ~, c~, x. The nature of any cations present (K, NH4, Na,
Mg,
Ca) also influences the solubility of the carrageenans. Semisynthetic
products, which contain only one type of ion and which may also be used
as film materials in accordance with the present invention, are also called
carrag(h)eenates.
The guar (also known as guar gum) suitable for use as a film
material in accordance with the present invention is a grey-white powder
which is obtained by grinding of the endosperm of the guar bean
(Cyamopsis tetragonobolus) belong to the family of leguminosae which was
originally endemic in India and Pakistan, but which is now also cultivated in
other countries, for example in the Southern USA. The principal consti-
tuent of guar with up to about 85% of the dry matter is guarane (guar gum,
cyamopsis gum); secondary constituents are proteins, lipids and cellulose.
Guarane itself is a polygalactomannan, i.e. a polysaccharide of which the
linear chain is made up of unsubstituted (see formula I) and C6-galactose-
substituted (see formula II) mannose units in ~3-D-(1 ~ 4) linkage.
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OH CH20H
Galactose ---~ O
HO
HO
CH20H O 6CH2
OH OH
p 5 -p
5 ,- ~ -O ,O 4 ~._-
HO ~- Mannose ---~ HO
3
I II
The ratio of I to II is about 2:1. Contrary to original assumptions, the
10 II units are not strictly alternating, but are arranged in pairs or
triplets in the
polygalactomannan molecule. Data on the molecular weight of guarane
vary significantly with values of around 2.2105 to 2.2106 g/mole depending
on the purity of the polysaccharide (the high value was obtained from a
highly purified product) and correspond to around 1350 to 13,500 sugar
unitslmacromolecule. Guarane is insoluble in most organic solvents.
The pectins also suitable for use as the film material are high
molecular weight glycosidic vegetable substances which are very
widespread in fruit, roots and leaves. The pectins consist essentially of
chains of 1,4-a-glycosid. linked galacturonic acid units in which 20 to 80%
of the acid groups are esterified with methanol, a distinction being drawn
between highly esterified pectins (>50%) and low-esterified pectins (<50%).
The pectins have a folded leaf structure and, accordingly, are in the middle
of starch and cellulose molecules. Their macromolecules still contain a
little glucose, galactose, xylose and arabinose and have mildly acidic
properties.
COOCH3 OH COOCH3 OH
-O O O O O-
OH OH ,! OH OH
O 1---O ~O
OH ~COOCH3 OH ~COOCH3
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11
Fruit pectin contains 95% and beet pectin up to 85% of galacturonic
acid. The molecular weights of the various pectins vary between 10,000
and 500,000. Their structural properties also depend largely on the degree
of polymerization. For example, dried fruit pectins form asbestos-like fibers
whereas flax pectins form fine granular powders.
The pectins are mainly prepared from the inner parts of citrus fruit
peel, fruit residues or even sugar beet chips by extraction with dilute acids.
Xanthan may also be used as a film material in accordance with the
present invention. Xanthan is a microbial anionic heteropolysaccharide
which is produced by Xanthomonas campestris and certain other species
under aerobic conditions and which has a molecular weight of 2 to 15
million dalton. Xanthan is made up of a chain with ~3-1,4-linked glucose
(cellulose) with side chains. The structure of the subgroups consists of
glucose, mannose, glucuronic acid, acetate and pyruvate, the number of
pyruvate units determining the viscosity of xanthan. Xanthan may be
represented by the following formula: CH20H CH20H
O O
OH p O
OH OH
O O
H3C-C-O-CH2
O
OH
HO
M+COO-
O O
O OH
M+ ' OOC O O
OH HO pH M+ = Na,K,1/2 Ca
HsC O
Basic unit of xanthan
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The celluloses and their derivatives are also suitable film materials.
Pure cellulose has the formal empirical composition (CsH~o05)~ and,
formally, is a ~i-1,4-polyacetal of cellobiose which, in turn, is made up of
two
molecules of glucose. Suitable celluloses consist of ca. 500 to 5000
glucose units and, accordingly, have average molecular weights of 50,000
to 500,000. According to the invention, cellulose derivatives obtainable
from cellulose by polymer-analog reactions may also be used as cellulose-
based film materials. These chemically modified celluloses include, for
example, products of esterification or etherification reactions in which
hydroxy hydrogen atoms have been substituted. However, celluloses in
which the hydroxy groups have been replaced by functional groups that are
not attached by an oxygen atom may also be used as cellulose derivatives.
The group of cellulose derivatives includes, for example, alkali metal
celluloses, carboxymethyl cellulose (CMC), cellulose esters and ethers and
aminocelluloses.
Besides cellulose and cellulose derivatives, (modified) dextrins,
starch and starch derivatives may also be used as film materials.
Suitable nonionic film materials are dextrins, for example oligomers
or polymers of carbohydrates which may be obtained by partial hydrolysis
of starches. The hydrolysis may be carried out by standard methods, for
example acid- or enzyme-catalyzed methods. The end products are
preferably hydrolysis products with average molecular weights of 400 to
500,000 g/mol. A polysaccharide with a dextrose equivalent (DE) of 0.5 to
40 and, more particularly, 2 to 30 is preferred, the DE being an accepted
measure of the reducing effect of a polysaccharide by comparison with
dextrose which has a DE of 100. Both maltodextrins with a DE of 3 to 20
and dry glucose sirups with a DE of 20 to 37 and also so-called yellow
dextrins and white dextrins with relatively high molecular weights of 2,000
to 30,000 glmole may be used.
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The oxidized derivatives of such dextrins are their reaction products
- with oxidizing agents which are capable of oxidizing at least one alcohol
function of the saccharide ring to the carboxylic acid function. Dextrins thus
oxidized and processes for their production are known, for example, from
European patent applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0
472 042 and EP-A-0 542 496 and from International patent applications
WO 92J18542, WO 93108251, WO 93116110, WO 94128030, WO 95107303,
WO 95!12619 and WO 95/20608. An oxidized olioosaccharide
corresponding to German patent application DE A-196 00 018 is also
suitable. A product oxidized at C6 of the saccharide ring can be particularly
advantageous.
Starch may also be used as the film material for the detergent
tablets according to the invention. Starch is a homoglycan in which the
glucose units are attached by a-glycoside bonds. Starch is made up of two
components of different molecular weight, namely ca. 20-30% straight-
chain amylose (molecular weight ca. 50,000 to 150,000) and 70-80% of
branched-chain amylopectin (molecular weight ca. 300,000 to 2,000,000).
Small quantities of lipids, phosphoric acid and cations are also present.
Whereas the amylose - on account of the bond in the 1,4-position - forms
long, helical intertwisted chains containing about 300 to 1,200 glucose
molecules, the amylopectin chain branches through a 1,6-bond after - on
average - 25 glucose units to form a branch-like structure containing about
1,500 to 12,000 glucose molecules. Besides pure starch, starch
derivatives obtainable from starch by polymer-analog reactions may also
be used as film materials for the purposes of the invention. Such
chemically modified starches include, for example, products of esterification
or etherification reactions in which hydroxy hydrogen atoms were
substituted. However, starches in which the hydroxy groups have been
replaced by functional groups that are not attached by an oxygen atom
may also be used as starch derivatives. The group of starch derivatives
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includes, for example, alkali metal starches, carboxymethyl starch (CMS),
starch esters and ethers and amino starches.
Among the proteins and modified proteins, gelatin is of outstanding
importance as film material. Gelatin is a polypeptide (molecular weight ca.
15,000 - >250,000 g/mole) which is mainly obtained by hydrolysis of the
collagen present in the skin and bones of animals under acidic or alkaline
conditions. The amino acid composition of gelatin largely corresponds to
that of the collagen from which it was obtained and varies according to its
provenance. The use of gelatin as a water-soluble capsule material is
particularly widespread in pharmacy (hard or soft gelatin capsules).
Other polymers suitable as film materials are synthetic, preferably
water-swellable andlor water-soluble polymers. Synthetic polymers such
as these may be "tailored" for the required permeability of the film during
storage and dissolution of the film in use. Particularly preferred detergent
tablets according to the invention are characterized in that the film material
is selected from a polymer or polymer mixture, the polymer or at least 50%
by weight of the polymer mixture being selected from
a) water-soluble nonionic polymers from the group of
a1 ) polyvinyl pyrrolidones,
a2) vinyl pyrrolidonelvinyl ester copolymers,
a3) cellulose ethers
b) water-soluble amphoteric polymers from the group of
b1 ) alkyl acrylamide/acrylic acid copolymers,
b2) alkyl acrylamidelmethacrylic acid copolymers,
b3) alkyl acrylamidelmethyl methacrylic acid copolymers,
b4) alkyl acrylamide/acrylic acidlalkylaminoalkyl (meth)acrylic acid co-
polymers,
b5) alkyl acrylamidelmethacrylic acidlalkylaminoalkyl (meth)acrylic acid
CA 02313875 2000-07-14
copolymers,
b6) alkyl acrylamidelmethyl methacrylic acidlalkylaminoalkyl (meth)-
acrylic acid copolymers,
b7) alkyl acrylamidelalkyl methacrylate/alkylaminoethyl methacrylatel
5 alkyl methacrylate copolymers,
b8) copolymers of
b8i) unsaturated carboxylic acids,
b8ii) cationically derivatized unsaturated carboxylic acids,
b8iii) optionally other ionic or nonionic monomers,
10 c) water-soluble zwitterionic polymers from the group of
c1 ) acrylamidoalkyl trialkylammonium chloridelacrylic acid copolymers
and alkali metal and ammonium salts thereof,
c2) acrylamidoalkyl trialkylammonium chloridelmethacrylic acid copoly-
mers and alkali metal and ammonium salts thereof,
15 c3) methacroyl ethyl betaine/methacrylate copolymers,
d) water-soluble anionic polymers from the group of
d1 ) vinyl acetatelcrotonic acid copolymers,
d2) vinyl pyrrolidonelvinyl acrylate copolymers,
d3) acrylic acid/ethyl acrylate/N-tert.butyl acrylamide terpolymers,
d4) graft polymers of vinyl esters, esters of acrylic acid or methacrylic
acid individually or in admixture copolymerized with crotonic acid,
acrylic acid or methacrylic acid with polyalkylene oxides and/or
polyalkylene glycols,
d5) grafted and crosslinked copolymers from the copolymerization of
d5i) at least one monomer of the nonionic type,
d5ii) at least one monomer of the ionic type,
d5iii) polyethylene glycol and
d5iv) a crosslinking agent,
d6) copolymers obtained by copolymerization of at least one monomer
CA 02313875 2000-07-14
16
of each of the following three groups:
d6i) esters of unsaturated alcohols and short-chain saturated
carboxylic acids and/or esters of short-chain saturated
alcohols and unsaturated carboxylic acids,
d6ii) unsaturated carboxylic acids,
d6iii) esters of long-chain carboxylic acids and unsaturated
alcohols and/or esters of the carboxylic acids of group d6ii)
with saturated or unsaturated, linear or branched C8_~8
alcohols,
d7) terpolymers of crotonic acid, vinyl acetate and an allyl or methallyl
ester,
d8) tetrapolymers and pentapolymers of
d8i) crotonic acid or allyloxyacetic acid,
d8ii) vinyl acetate or vinyl propionate,
d8iii) branched allyl or methallyl esters,
d8iv) vinyl ethers, vinyl esters or straight-chain allyl or methallyl
esters,
d9) crotonic acid copolymers with one or more monomers from the
group consisting of ethylene, vinyl benzene, vinyl methyl ether,
acrylamide and water-soluble salts thereof,
d 10) terpolymers of vinyl acetate, crotonic acid and vinyl esters of a
saturated aliphatic monocarboxylic acid branched in the a-position,
e) water-soluble cationic polymers from the group of
e1 ) quaternized cellulose derivatives,
e2) polysiloxanes containing quaternary groups,
e3) cationic guar derivatives,
e4) polymeric dimethyl diallylammonium salts and copolymers thereof
with esters and amides of acrylic acid and methacrylic acid,
e5) copolymers of vinyl pyrrolidone with quaternized derivatives of
CA 02313875 2000-07-14
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dialkylaminoacrylate and methacrylate,
e6) vinyl pyrrolidonelmethoimidazolinium chloride copolymers,
e7) quaternized polyvinyl alcohol,
e8) polymers known by the INCI names of polyquaternium 2,
polyquaternium 17, polyquaternium 18 and polyquaternium 27.
Water-soluble polymers in the context of the invention are polymers
of which more than 2.5% by weight are soluble in water at room
temperature.
The films of the detergent tablets according to the invention may be
made from individual representatives of the polymers mentioned above
although mixtures or multilayer "laminates" of the polymers may also be
used. The polymers are described in more detailed in the following.
According to the invention, preferred water-soluble polymers are
nonionic. The following are examples of suitable nonionic polymers:
- Polyvinyl pyrrolidones which are marketed, for example, under the
name of Luviskol~ (BASF). Polyvinyl pyrrolidones are preferred
nonionic polymers for the purposes of the invention.
Polyvinyl pyrrolidones [poly(1-vinyl-2-pyrrolidinones)], PVPs for
short, are polymers corresponding to general formula (III):
CH-CH2
N
~O (III)
n
which are obtained by radical polymerization of 1-vinyl pyrrolidone by
CA 02313875 2000-07-14
- 18
solution or suspension polymerization using radical formers (peroxides, azo
compounds) as initiators. The ionic polymerization of the monomer only
gives products of low molecular weight. Commercially available polyvinyl
pyrrolidones have molecular weights of about 2500 to 750,000 g/mole
which are characterized by expressing the K values and - depending on
their K value - have glass transition temperatures of 130 to 175°C.
They
are marketed as white hygroscopic powders or as aqueous solutions.
Polyvinyl pyrrolidones are readily soluble in water and in a number of
organic solvents (alcohols, ketones, glacial acetic acid, chlorinated
hydrocarbons, phenols, etc.).
- Vinyl pyrrolidonelvinyl acetate copolymers which are marketed, for
example under the registered name of Luviskol~ (BASF). Luviskol~ VA
64 and Luviskol~ VA 73, both vinyl pyrrolidone/vinyl acetate
copolymers, are particularly preferred nonionic polymers.
The vinyl ester polymers are polymers obtainable from vinyl esters
containing a group corresponding to formula (IV):
- CH2-CH-
O
C
// 1
O R (IV)
as the characteristic basic unit of the macromolecules. Of these, the vinyl
acetate polymers (R = CH3) with polyvinyl acetates, as by far the most
important representatives, have the greatest commercial significance.
The polymerization of the vinyl esters is carried out by various radical
CA 02313875 2000-07-14
- 19
polymerization processes (solution polymerization, suspension
polymerization, emulsion polymerization, bulk polymerization). Copolymers
of vinyl acetate with vinyl pyrrolidone contain monomer units corresponding
to formulae (I) and (II).
- Cellulose ethers, such as hydroxypropyl cellulose, hydroxyethyl
cellulose and methyl hydroxypropyl cellulose, which are marketed for
example under the registered names of Culminal~ and Benecel~
(AQUALON).
Cellulose ethers correspond to general formula (V):
ROCH2 OR
O O RO O .
Ro o d (v)
R RO H2
in which R represents H or an alkyl, alkenyl, alkinyl, aryl or alkylaryl
group.
In preferred products, at least one R in formula (V) stands for
-CH2CH2CH2-OH or -CH2CH2-OH. On an industrial scale, cellulose ethers
are produced by etherification of alkali metal cellulose (for example with
ethylene oxide). Cellulose ethers are characterized by the average degree
of substitution DS or the molar degree of substitution MS which indicates
how many hydroxy groups of an anhydroglucose unit of the cellulose have
reacted with the etherifying agent or how many moles of the etherifying
agent on average have been added onto one anhydroglucose unit.
Hydroxyethyl celluloses are soluble in water where they have a DS of about
0.6 or higher or an MS of about 1 or higher. Commercially available
hydroxyethyl or hydroxypropyl celluloses have degrees of substitution of
0.85 to 1.35 (DS) or 1.5 to 3 (MS). Hydroxyethyl and hydroxypropyl
celluloses are marketed as yellowish-white, odorless and tasteless
CA 02313875 2000-07-14
- 20
powders with various degrees of polymerization. Hydroxyethyl and
hydroxypropyl celluloses are soluble in cold and hot water and in certain
(water-containing) organic solvents, but are insoluble in most (water-free)
organic solvents. Their aqueous solutions are relatively non-sensitive to
changes in pH or to the addition of an electrolyte.
Polyvinyl alcohols, referred to in short as PVALs, are polymers with
the following general structure:
[-CH2-CH(OH)-]~
which also contain small amounts of structural units of the following type:
[-CH2-CH(OH)-CH(OH)-CH2]
Since the corresponding monomer, vinyl alcohol, is not stable in free form,
polyvinyl alcohols are produced via polymer-analog reactions by hydrolysis
and - on an industrial scale - above all by alkali-catalyzed
transesterification
of polyvinyl acetates with alcohols (preferably methanol) in solution.
PVALs containing a predetermined residual percentage of acetate groups
can also be obtained by these industrial processes.
Commercially available PVALs (for example Mowiol~ types, prod-
ucts of Hoechst) are marketed as white-yellowish powders or granules with
degrees of polymerization of ca. 500 to 2,500 (corresponding to molecular
weights of ca. 20,000 to 100,000 glmole) and have different degrees of
hydrolysis of 98-99 or 87-89 mole-%. Accordingly, they are partly
saponified polyvinyl acetates with a residual content of acetyl groups of ca.
1-2 or 11-13 mole-%.
The solubility of PVAL in water can be reduced and thus selectively
adjusted to required values by aftertreatment with aldehydes (acetaliz-
ation), by complexing with Ni or Cu salts or by treatment with dichromates,
CA 02313875 2000-07-14
' 21
boric acid, borax.
- Other polymers suitable for the purposes of the invention are water-
soluble "amphopolymers". "Amphopolymers" is the generic term for
amphoteric polymers, i.e. polymers which contain both free amino groups
and free -COOH or -S03H groups in the molecule and which are capable of
forming inner salts, zwitterionic polymers which contain quaternary
ammonium groups and -COO' or -S03 groups in the molecule, and for
polymers which contain -COOH or -S03H groups and quaternary
ammonium groups. One example of an amphopolymer suitable for use in
accordance with the invention is the acrylic resin obtainable under the
name of Amphomer0, which is a copolymer of tert.butyl aminoethyl
methacrylate, N-(1,1,3,3-tetramethylbutyl)acrylamide and two or more
monomers from the group consisting of acrylic acid, methacrylic acid and
simple esters thereof. Other preferred amphopolymers consist of
unsaturated carboxylic acids (for example acrylic and methacrylic acid),
cationically derivatized unsaturated carboxylic acids (for example
acrylamidopropyl trimethyl ammonium chloride) and optionally other ionic
or nonionic monomers as known, for example, from DE-A-39 29 973 and
the prior art literature cited therein. According to the invention,
terpolymers
of acrylic acid, methyl acrylate and methacrylamidopropyl trimonium
chloride, which are commercially available under the name of Merquat~
2001 N, are particularly preferred amphopolymers. Other suitable
amphoteric polymers are, for example, the octyl acrylamidelmethyl meth-
acrylateltert.butylaminoethyl methacrylatel2-hydroxypropyl methacrylate
copolymers obtainable under the names of AmphomerO and Amphomer~
LV-71 (DELFT NATIONAL).
Suitable zwitterionic polymers are, for example, the polymers
disclosed in German patent applications DE 39 29 973, DE 21 50 557, DE
28 17 369 and DE 37 08 451. Acrylamidopropyl trimethylammonium
chloridelacrylic acid or methacrylic acid copolymers and alkali metal and
CA 02313875 2000-07-14
° 22
ammonium salts thereof are preferred zwitterionic polymers. Other suitable
zwitterionic polymers are methacroyl ethyl betainelmethacrylate copoly-
mers which are commercially obtainable under the name of AmersetteC~7
(AMERCHOL).
Anionic polymers suitable for the purposes of the present invention
include:
- Vinyl acetatelcrotonic acid copolymers which are marketed, for
example, under the names of Resyn~ (NATIONAL STARCH), Luviset~
(BASF) and Gafset~ (GAF).
Besides monomer units corresponding to formula (IV) above, these
polymers also contain monomer units corresponding to general formula
(VI ):
(-CH(CH3)-CH(COOH)-]" (VI)
- Vinyl pyrrolidone/vinyl acrylate copolymers obtainable, for example,
under the registered name of Luviflex~ (BASF). A preferred polymer is
the vinyl pyrrolidonelacrylate terpolymer obtainable under the name of
Luviflex~ VBM-35 (BASF).
Acrylic acidlethylacrylatelN-tert.butyl acrylamide terpolymers which are
marketed, for example, under the name of Ultrahold~ strong (BASF).
- Graft polymers of vinyl esters, esters of acrylic acid or methacrylic acid
individually or in admixture copolymerized with crotonic acid, acrylic
acid or methacrylic acid with polyalkylene oxides and/or polyalkylene
glycols.
Corresponding grafted polymers of vinyl esters, esters of acrylic acid
CA 02313875 2000-07-14
- 23
or methacrylic acid individually or in admixture with other copolymerizable
compounds on polyalkylene glycols are obtained by high-temperature
polymerization in homogeneous phase by stirring the polyalkylene glycols
into the monomers, i.e. vinyl esters, esters of acrylic or methacrylic acid,
in
the presence of radical formers.
Suitable vinyl esters are, for example, vinyl acetate, vinyl propionate,
vinyl butyrate, vinyl benzoate while suitable esters of acrylic or methacrylic
acid are those obtainable with low molecular weight aliphatic alcohols, i.e.
in particular ethanol, propanol, isopropanol, 1-butanol, 2-butanol, 2-methyl-
1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2,2-
dimethyl-1-propanol, 3-methyl-1-butanol; 3-methyl-2-butanol, 2-methyl-2-
butanol, 2-methyl-1-butanol, 1-hexanol.
Suitable polyalkylene glycols are, in particular, polyethylene glycols
and polypropylene glycols. Polymers of ethylene glycol which correspond
to general formula (VII):
H-(O-CH2-CHZ)"-OH (VI I)
where n may assume values of 1 (ethylene glycol) to several thousand.
Various nomenclatures are used for polyethylene glycols which can lead to
confusion. It is common practice to indicate the mean relative molecular
weight after the initials "PEG", so that "PEG 200" characterizes a
polyethylene glycol having a relative molecular weight of about 190 to
about 210. Cosmetic ingredients are covered by another nomenclature in
which the initials PEG are followed by a hyphen and the hyphen is in turn
directly followed by a number which corresponds to the index n in general
formula VII above. Under this nomenclature (so-called INCI nomenclature,
CTFA International Cosmetic Ingredient Dictionary and Handbook, 5th
Edition, The Cosmetic, Toiletry and Fragrance Association, Washington,
1997), PEG-4, PEG-6, PEG-8, PEG-9, PEG-10, PEG-12, PEG-14 and
CA 02313875 2000-07-14
' 24
PEG-16, for example, may be used. Polyethylene glycols are commercially
obtainable, for example, under the names of Carbowax~ PEG 200 (Union
Carbide), Emkapol~ 200 (ICI Americas), Lipoxol~ 200 MED (HULS
America), Polyglycol~ E-200 (Dow Chemical), Alkapol~ PEG 300 (Rhone-
Poulenc), Lutrol~ E300 (BASF) and the corresponding commercial names
with higher numbers.
Polypropylene glycols (PPGs) are polymers of propylene glycol
which correspond to general formula (VIII):
H-(O- iH-CH2)~-OH (VIII)
CH3
where n may assume a value of 1 (propylene glycol) to several thousand.
Di-, tri- and tetrapropylene glycol, i.e. representatives where n = 2, 3 and 4
in formula VIII, are of particular commercial significance.
More particularly, the vinyl acetate copolymers grafted onto poly-
ethylene glycols and the polymers of vinyl acetate and crotonic acid grafted
onto polyethylene glycols may be used.
- Grafted and crosslinked copolymers from the copolymerization of
i) at least one monomer of the nonionic type,
ii) at least one monomer of the ionic type,
iii) polyethylene glycol and
iv) a crosslinking agent.
The polyethylene glycol used has a molecular weight of 200 to
several million and preferably in the range from 300 to 30,000.
The nonionic monomers may be of various types, among which the
following are preferred: vinyl acetate, vinyl stearate, vinyl laurate, vinyl
propionate, allyl stearate, allyl laurate, diethyl maleate, allyl acetate,
methyl
CA 02313875 2000-07-14
° 25
methacrylate, cetyl vinyl ether, stearyl vinyl ether and 1-hexene.
The nonionic monomers may also be of various types, among which
crotonic acid, allyloxyacetic acid, vinyl acetic acid, malefic acid, acrylic
acid
and methacrylic acid are present with particular advantage in the graft
polymers.
Preferred crosslinking agents are ethylene glycol dimethacrylate,
diallyl phthalate, ortho-, meta- and para-divinyl benzene, tetraallyloxy
ethane and polyallyl saccharoses containing 2 to 5 allyl groups per
molecule of saccharin.
The grafted and crosslinked copolymers described above are
preferably formed from:
i) 5 to 85% by weight of at least one monomer of the nonionic type,
ii) 3 to 80% by weight of at least one monomer of the ionic type,
iii) 2 to 50% by weight and preferably 5 to 30% by weight of polyethyl-
ene glycol and
iv) 0.1 to 8% by weight of a crosslinking agent, the percentage of the
crosslinking agent being determined by the ratio of the total weights
of i), ii) and iii).
- Copolymers obtained by copolymerization of at least one monomer from
each of the following three groups:
i) esters of unsaturated alcohols and short-chain saturated carboxylic
acids andlor esters of short-chain saturated alcohols and
unsaturated carboxylic acids,
ii) unsaturated carboxylic acids,
iii) esters of long-chain carboxylic acids and unsaturated alcohols
andlor esters of the carboxylic acids of group ii) with saturated or
unsaturated, linear or branched C&~a alcohol.
Short-chain carboxylic acids or alcohols in the context of the present
CA 02313875 2000-07-14
' 26
invention are understood to be those containing 1 to 8 carbon atoms, the
carbon chains of these compounds optionally being interrupted by two-
bond hetero groups, such as -O-, -NH-, -S-.
- Terpolymers of crotonic acid, vinyl acetate and an allyl or methallyl
ester.
These terpolymers contain monomer units corresponding to general
formulae (II) and (IV) (see above) and monomer units of one or more allyl
or methallyl esters corresponding to formula (IX):
R' R3
RZ- i -C(O)-O-CH2 C=CH2 (IX)
CH3
where R3 represents -H or -CH3, R2 represents -CH3 or -CH(CH3)2 and R'
represents -CH3 or is a saturated, linear or branched C~_6 alkyl group and
the sum of the carbon atoms in the substituents R' and R2 is preferably 7,
6, 5, 4, 3 or 2.
The terpolymers mentioned above preferably result from the
copolymerization of 7 to 12% by weight of crotonic acid, 65 to 86% by
weight and preferably 71 to 83% by weight of vinyl acetate and 8 to 20% by
weight and preferably 10 to 17% by weight of allyl or methallyl esters
corresponding to formula (IX).
- Tetrapolymers and pentapolymers of
i) crotonic acid or allyloxyacetic acid,
ii) vinyl acetate or vinyl propionate,
iii) branched allyl or methallyl esters,
CA 02313875 2000-07-14
27
iv) vinyl ethers, vinyl esters or straight-chain allyl or methallyl esters.
- Crotonic acid copolymers with one or more monomers from the group
consisting of ethylene, vinyl benzene, vinyl methyl ether, acrylamide
and water-soluble salts thereof.
- Terpolymers of vinyl acetate, crotonic acid and vinyl esters of a
saturated aliphatic monocarboxylic acid branched in the a-position.
Anionic polymers suitable as film materials are, in particular,
polycarboxylateslpolycarboxylic acids, polymeric polycarboxylates,
polyaspartic acid, polyacetals and dextrins which are described in the
following.
Useful organic film materials are, for example, the polycarboxylic
acids usable in the form of their sodium salts, but also in free form.
Polymeric polycarboxylates are, for example, the alkali metal salts of
polyacrylic or polymethacrylic acid, for example those with a relative
molecular weight of 500 to 70,000 g/mole.
The molecular weights mentioned in this specification for polymeric
polycarboxylates are weight-average molecular weights MW of the particular
acid form which, basically, were determined by gel permeation
chromatography (GPC) using a UV detector. The measurement was
carried out against an external polyacrylic acid standard which provides
realistic molecular weight values by virtue of its structural similarity to
the
polymers investigated. These values differ distinctly from the molecular
weights measured against polystyrene sulfonic acids as standard. The
molecular weights measured against polystyrene sulfonic acids are
generally higher than the molecular weights mentioned in this specification.
Particularly suitable polymers are polyacrylates which preferably
have a molecular weight of 2,000 to 20,000 glmole. By virtue of their
CA 02313875 2000-07-14
28
superior solubility, preferred representatives of this group are the short-
chain polyacrylates which have molecular weights of 2,000 to 10,000
glmole and, more particularly, 3,000 to 5,000 glmole.
Also suitable are copolymeric polycarboxylates, particularly those of
acrylic acid with methacrylic acid and those of acrylic acid or methacrylic
acid with malefic acid. Acrylic acidlmaleic acid copolymers containing 50 to
90% by weight of acrylic acid and 50 to 10% by weight of malefic acid have
proved to be particularly suitable. Their relative molecular weights, based
on the free acids, are generally in the range from 2,000 to 70,000 g/mole,
preferably in the range from 20,000 to 50,000 glmole and more preferably
in the range from 30,000 to 40,000 glmole.
In order to improve solubility in water, the polymers may also contain
allyl sulfonic acids such as, for example, allyloxybenzene sulfonic acid and
methallyl sulfonic acid as monomer.
Other particularly preferred film materials are biodegradable
polymers of more than two different monomer units, for example those
which contain salts of acrylic acid and malefic acid and vinyl alcohol or
vinyl
alcohol derivatives as monomers or those which contain salts of acrylic
acid and 2-alkylallyl sulfonic acid and sugar derivatives as monomers.
Other preferred copolymeric film materials are those which are
described in German patent applications DE-A-43 03 320 and DE A-44 17
734 and which preferably contain acrolein and acrylic acidlacrylic acid salts
or acrolein and vinyl acetate as monomers.
Other preferred film materials are polymeric aminodicarboxylic acids,
salts or precursors thereof. Polyaspartic acids or salts and derivatives
thereof are particularly preferred.
Other suitable film materials are polyacetals which may be obtained
by reaction of dialdehydes with polyol carboxylic acids containing 5 to 7
carbon atoms and at least three hydroxyl groups. Preferred polyacetals
are obtained from dialdehydes, such as glyoxal, glutaraldehyde, terephthal-
CA 02313875 2000-07-14
' 29
aldehyde and mixtures thereof and from polyol carboxylic acids, such as
gluconic acid and/or glucoheptonic acid.
Other polymers usable with advantage as film materials are cationic
polymers. Among the cationic polymers, permanently cationic polymers
are preferred. In the context of the invention, "permanently cationic"
polymers are polymers which contain a cationic group irrespective of the
pH value of the detergent (i.e. both the film and the rest of the detergent
tablet). Such polymers are generally polymers which contain a quaternary
nitrogen atom, for example in the form of an ammonium group.
The following are examples of preferred cationic polymers:
- Quaternized cellulose derivatives commercially obtainable under the
names of Celquat~ and Polymer JR~. The compounds Celquat~ H
100, Celquat~ L 200 and Polymer JR~ 400 are preferred quaternized
cellulose derivatives.
- Polysiloxanes containing quaternary groups such as, for example, the
commercially available products Q2-7224 (manufacturer: Dow Corning;
a stabilized trimethyl silylamodimethicone), Dow Corning~ 929
Emulsion (containing a hydroxylamino-modified silicone which is also
known as amodimethicone), SM-2059 (manufacturer: General Electric),
SLM-55067 (manufacturer: Wacker) and Abil~-Quat 3270 and 3272
(manufacturer: Th. Goldschmidt; diquaternary polydimethyl siloxanes,
quaternium-80).
- Cationic guar derivatives such as, in particular, the products marketed
under the names of Cosmedia~Guar and Jaguar.
- Polymeric dimethyl diallylammonium salts and copolymers thereof with
esters and amides of acrylic acid and methacrylic acid. The products
CA 02313875 2000-07-14
' 30
commercially obtainable under the names of MerquatO 100
(poly(dimethyl diallylammonium chloride)) and Merquat~ 550 (dimethyl
diallylammonium chloridelacrylamide copolymer) are examples of such
cationic polymers.
- Copolymers of vinyl pyrrolidone with quaternized derivatives of dialkyl
aminoacrylate and methacrylate, such as for example vinyl pyrrolidonel
dimethylaminomethacrylate copolymers quaternized with diethyl sulfate.
Compounds such as these are commercially available under the names
of Gafquat~ 734 and Gafquat~ 755.
- Vinyl pyrrolidonelmethoimidazolinium chloride copolymers as marketed
under the name of Luviquat~.
- Quaternized polyvinyl alcohol
and the polymers containing quaternary nitrogen atoms in the main
polymer chain known by the names of
- polyquaternium 2,
- polyquaternium 17,
- polyquaternium 18 and
- polyquatemium 27.
The names of the above-mentioned polymers are based on the so-called
INCI nomenclature: particulars can be found in the CTFA International
Cosmetic Ingredient Dictionary and Handbook, 5t" Edition, The Cosmetic,
Toiletry and Fragrance Association, Washington, 1997, to which reference
is expressly made here.
According to the invention, preferred cationic polymers are
quaternized cellulose derivatives and polymeric dimethyl diallylammonium
salts and copolymers thereof. Cationic cellulose derivatives, more
~
CA 02313875 2000-07-14
31
particularly the commercial product Polymer0 JR 400, are most particularly
preferred cationic polymers.
Irrespective of the chemical composition of the film, preferred
detergent tablets according to the invention are characterized in that the
film which closes the cavity has a thickness of 1 to 150 pm, preferably 2 to
100 Nm, more preferably 5 to 75 pm and most preferably 10 to 50 pm.
Together with the tablet which has at least one cavity, the film firmly
bonded to the tablet forms the detergent tablet according to the invention.
In the case of closed cavity tablets, the structure of the tablet according to
the invention is reminiscent of a "drum" in which a cavity is closed by a
film.
According to the invention, the cavity may be left unfilled so that only the
visual appeal of such tablets is utilized, although preferred detergent
tablets according to the invention are characterized in that additional active
substance is present in the space enclosed by the tablet.
In this way, a tablet according to the invention comprises two
regions in which different ingredients may be present or in which different
release mechanisms and dissolving kinetics may be put into effect. The
active substance present in the cavity may assume any aggregate state or
may be presented in any form. Preferred detergent tablets contain the
additional active substance in liquid, gel-like, paste-like or solid form.
Where liquid, gel-form or paste-form active substances or active-
substance mixtures are incorporated, the composition of the tablet and the
film has to be adapted to the filling in order to prevent premature
destruction of the film or a loss of active substance through the tablet.
Where solid substances are incorporated in the cavity, this is only
necessary to a small extent (chemical incompatibilities), so that preferred
detergent tablets contain additional active substance in particle form,
preferably in powder, granular, extruded, pelleted, prilled, flaked or
tabletted form.
The cavity closed by the film may be completely filled with additional
- CA 02313875 2000-07-14
32
active substance. However, the cavity may also be only partly filled before
it is closed in order in this way to enable the particles or liquids
introduced
into the cavity to move therein. Attractive visual effects can be achieved in
particular when the cavity is filled with regularly shaped, relatively large
particles. In this case, preferred detergent tablets are those in which the
volume ratio of the space enclosed by the film and the tablet to the active
substance present in that space is from 1:1 to 100:1, preferably from 1.1:1
to 50:1, more preferably from 1.2:1 to 25:1 and most preferably from 1.3:1
to 10:1. In this terminology, a volume ratio of 1:1 means that the cavity is
completely filled.
Depending on the size of the cavity, the density of the tablet, the
density of the active substance in the cavity and the level to which the
cavity is filled, the other active substance in the cavity can make up
different percentages of the tablet as a whole. In this case, preferred
detergent tablets are those in which the ratio by weight of the tablet to the
active substance present in the space enclosed by the film and the tablet is
from 1:1 to 100:1, preferably 2:1 to 80:1, more preferably from 3:1 to 50:
and most preferably from 4:1 to 30:1. The ratio by weight defined above is
the ratio between the weight of the unfilled tablet ("basic tablet") and the
weight of the filling. The weight of the film is not included in this
calculation.
The time at which the substance present in the cavity is released
can be determined in advance by suitably making up the tablet and the film
material. For example, the film may dissolve almost instantaneously so
that the active substance present in the cavity is released into the wash
liquor right at the beginning of the wash cycle. Alternatively, the film may
dissolve so poorly that the tablet dissolves first and releases the active
substance present in the cavity.
Depending on this release mechanism, it is possible for example to
produce tablets in which the active substance present in the cavity is
dissolved in the wash liquor before or after the constituents of the tablet
CA 02313875 2000-07-14
' 33
have dissolved. Thus, on the one hand, detergent tablets in which the
active substance present in the space enclosed by the film and the tablet
dissolves more quickly than the basic tablet are preferred.
On the other hand, however, detergent tablets in which the active
substance present in the space enclosed by the film and the tablet
dissolves more slowly than the basic tablet are also preferred embodiments
of the present invention.
The tablets according to the invention consist of a basic tablet with
one or more cavities, ~Im(s) which closes) these cavity(ies) and active
substances) optionally present in the cavity(ies). The film materials and
preferred physical parameters of the films were described in the foregoing.
The ingredients of the basic tablet, which may also be active substances
present in the cavity, will now be described and preferred physical
parameters for basic tablets and cavity fillings will also be listed. By
incorporating certain ingredients, it is possible on the one hand selectively
to accelerate the solubility of the cavity filling; on the other hand, the
release of certain ingredients from that filling can lead to advantages in the
washingldishwashing process. Ingredients which, preferably, are at
released partly localized in the cavity are, for example, the surfactants,
enzymes, soil-release polymers, builders, bleaching agents, bleach
activators, bleach catalysts, optical brighteners, silver protectors, etc.
described in the following.
In preferred embodiments of the present invention, the basic tablet
has a high specific gravity. According to the invention, detergent tablets
which are characterized in that the basic tablet has a density above 1000
kgdm-3, preferably above 1025 kgdm-3, more preferably above 1050 kgdm-3
and most preferably above 1100 kgdm-3 are preferred.
Further particulars of physical parameters of the basic tablet and the
final detergent tablets and particulars of their production can be found in
the following. Preferred ingredients of the basic tablet will now be
CA 02313875 2000-07-14
' 34
described.
According to the present invention, preferred detergent tablets are
characterized in that the basic tablet contains builders in quantities of 1 to
100% by weight, preferably in quantities of 5 to 95% by weight, more
preferably in quantities of 10 to 90% by weight and most preferably in
quantities of 20 to 85% by weight, based on the weight of the basic tablet.
The detergent tablets according to the invention may contain any of
the builders typically used in detergents, i.e. in particular zeolites,
silicates,
carbonates, organic cobuilders and - providing there are no ecological
objections to their use - also the phosphates.
Suitable crystalline layered sodium silicates correspond to the
general formula NaMSiXO~+ly H20, where M is sodium or hydrogen, x is a
number of 1.9 to 4 and y is a number of 0 to 20, preferred values for x
being 2, 3 or 4. Crystalline layered silicates such as these are described,
for example, in European patent application EP-A-0 164 514. Preferred
crystalline layered silicates corresponding to the above formula are those in
which M is sodium and x assumes the value 2 or 3. Both Vii- and 8-sodium
disilicates Na2Si205y H20 are particularly preferred, ~i-sodium disilicate
being obtainable, for example, by the process described in International
patent application WO-A- 91!08171.
Other useful builders are amorphous sodium silicates with a
modulus (Na20:Si02 ratio) of 1:2 to 1:3.3, preferably 1:2 to 1:2.8 and more
preferably 1:2 to 1:2.6 which dissolve with delay and exhibit multiple wash
cycle properties. The delay in dissolution in relation to conventional
amorphous sodium silicates can have been obtained in various ways, for
example by surface treatment, compounding, compacting or by overdrying.
In the context of the invention, the term "amorphous" is also understood to
encompass "X-ray amorphous". In other words, the silicates do not
produce any of the sharp X-ray reflexes typical of crystalline substances in
X-ray diffraction experiments, but at best one or more maxima of the
CA 02313875 2000-07-14
scattered X-radiation which have a width of several degrees of the
- diffraction angle. However, particularly good builder properties may even
be achieved where the silicate particles produce crooked or even sharp
diffraction maxima in electron diffraction experiments. This may be
5 interpreted to mean that the products have microcrystalline regions
between 10 and a few hundred nm in size, values of up to at most 50 nm
and, more particularly, up to at most 20 nm being preferred. So-called X-
ray amorphous silicates such as these, which also dissolve with delay in
relation to conventional waterglasses, are described for example in
10 German patent application DE-A-44 00 024. Compacted amorphous
silicates, compounded amorphous silicates and overdried X-ray-amorphous
silicates are particularly preferred.
Preferred detergent tablets according to the invention are
characterized in that the basic tablet contains silicate(s), preferably alkali
15 metal silicates and, more preferably, crystalline or amorphous alkali metal
disilicates in quantities of 10 to 60% by weight, preferably in quantities of
15 to 50% by weight and more preferably in quantities of 20 to 40% by
weight, based on the weight of the basic tablet.
The finely crystalline, synthetic zeolite containing bound water used
20 in accordance with the invention is preferably zeolite A andlor zeolite P.
Zeolite MAP~ (Crosfield) is a particularly preferred P-type zeolite.
However, zeolite X and mixtures of A, X and/or P are also suitable.
According to the invention, it is preferred to use, for example, a
commercially obtainable co-crystallizate of zeolite X and zeolite A (ca. 80%
25 by weight zeolite X) v~ihich is marketed by CONDEA Augusta S.p.A. under
the name of VEGOBOND AX~ and which may be described by the
following formula:
nNa20 ~ (1-n)K20 ~ AI203 ~ (2 - 2.5)Si02 ~ (3.5 - 5.5) HZO.
CA 02313875 2000-07-14
36
The zeolite may be used both as a builder in a granular compound and for
"powdering" the entire mixture to be tabletted, both these options normally
being used to incorporate the zeolite in the premix. Suitable zeolites have
a mean particle size of less than 10 p,m (volume distribution, as measured
by the Coulter Counter Method) and contain preferably 18 to 22% by
weight and more preferably 20 to 22% by weight of bound water.
The generally known phosphates may of course also be used as
builders providing their use should not be avoided on ecological grounds.
Among the large number of commercially available phosphates, alkali
metal phosphates have the greatest importance in the detergent industry,
pentasodium triphosphate and pentapotassium triphosphate (sodium and
potassium tripolyphosphate) being particularly preferred.
"Alkali metal phosphates" is the collective term for the alkali metal
(more particularly sodium and potassium) salts of the various phosphoric
acids, including metaphosphoric acids (HP03)" and orthophosphoric acid
(H3P04) and representatives of higher molecular weight. The phosphates
combine several advantages: they act as alkalinity sources, prevent lime
deposits on machine parts and lime incrustations in fabrics and, in addition,
contribute towards the cleaning effect.
Sodium dihydrogen phosphate (NaHZP04) exists as the dihydrate
(density 1.91 gcm-3, melting point 60°) and as the monohydrate (density
2.04 gcm-3). Both salts are white readily water-soluble powders which, on
heating, lose the water of crystallization and, at 200°C, are converted
into
the weakly acidic diphosphate (disodium hydrogen diphosphate,
Na2H2P20~) and, at higher temperatures, into sodium trimetaphosphate
(Na3P309) and Maddrell's salt (see below). NaH2P04 shows an acidic
reaction. It is formed by adjusting phosphoric acid with sodium hydroxide
to a pH value of 4.5 and spraying the resulting "mash". Potassium
dihydrogen phosphate (primary or monobasic potassium phosphate,
potassium biphosphate, KDP), KHZP04, is a white salt with a density of
CA 02313875 2000-07-14
37
2.33 gcm-3, has a melting point of 253° [decomposition with formation
of
- potassium polyphosphate (KP03)X] and is readily soluble in water.
Disodium hydrogen phosphate (secondary sodium phosphate),
Na2HP04, is a colorless, readily water-soluble crystalline salt. It exists in
water-free form and with 2 moles (density 2.066 gcm-3, water loss at
95°), 7
moles (density 1.68 gcm-3, melting point 48° with loss of 5 H20) and 12
moles of water (density 1.52 gcm-3, melting point 35° with loss of 5
H20),
becomes water-free at 100° and, on fairly intensive heating, is
converted
into the diphosphate Na4P20~. Disodium hydrogen phosphate is prepared
by neutralization of phosphoric acid with soda solution using phenol-
phthalein as indicator. Dipotassium hydrogen phosphate (secondary or
dibasic potassium phosphate), K2HP04, is an amorphous white salt which
is readily soluble in water.
Trisodium phosphate, tertiary sodium phosphate, Na3P04, consists
of colorless crystals which have a density of 1.62 gcm-3 and a melting point
of 73-76° (decomposition) as the dodecahydrate, a melting point of
100° as
the decahydrate (corresponding to 19-20% P205) and a density of 2.536
gcm-3 in water-free form (corresponding to 39-40% P205). Trisodium
phosphate is readily soluble in water through an alkaline reaction and is
prepared by concentrating a solution of exactly 1 mole of disodium
phosphate and 1 mole of NaOH by evaporation. Tripotassium phosphate
(tertiary or tribasic potassium phosphate), K3P04, is a white deliquescent
granular powder with a density of 2.56 gcm-3, has a melting of 1340°
and is
readily soluble in water through an alkaline reaction. It is formed, for
example, when Thomas slag is heated with coal and potassium sulfate.
Despite their higher price, the more readily soluble and therefore highly
effective potassium phosphates are often preferred to corresponding
sodium compounds in the detergent industry.
Tetrasodium diphosphate (sodium pyrophosphate), Na4P207, exists
in water-free form (density 2.534 gcm-3, melting point 988°, a figure
of 880°
CA 02313875 2000-07-14
38
has also been mentioned) and as the decahydrate (density 1.815 - 1.836
gcm-3, melting point 94° with loss of water). Both substances are
colorless
crystals which dissolve in water through an alkaline reaction. Na4P207 is
formed when disodium phosphate is heated to >200° or by reacting
phosphoric acid with soda in a stoichiometric ratio and spray-drying the
solution. The decahydrate complexes heavy metal salts and hardness
salts and, hence, reduces the hardness of water. Potassium diphosphate
(potassium pyrophosphate), K4P207, exists in the form of the trihydrate and
is a colorless hygroscopic powder with a density of 2.33 gcm-3 which is
soluble in water, the pH value of a 1 % solution at 25° being 10.4.
Relatively high molecular weight sodium and potassium phosphates
are formed by condensation of NaH2P04 or KH2P04. They may be divided
into cyclic types, namely the sodium and potassium metaphosphates, and
chain types, the sodium and potassium polyphosphates. The chain types
in particular are known by various different names: fused or calcined
phosphates, Graham's salt, Kurrol's salt and Maddrell's salt. All higher
sodium and potassium phosphates are known collectively as condensed
phosphates.
The industrially important pentasodium triphosphate, Na5P30~o
(sodium tripolyphosphate), is a non-hygroscopic white water-soluble salt
which crystallizes without water or with 6 H20 and which has the general
formula Na0-[P(O)(ONa)-O]~-Na where n = 3. Around 17 g of the salt free
from water of crystallization dissolve in 100 g of water at room temperature,
around 20 g at 60° and around 32 g at 100°. After heating of the
solution
for 2 hours to 100°, around 8% orthophosphate and 15% diphosphate are
formed by hydrolysis. In the preparation of pentasodium triphosphate,
phosphoric acid is reacted with soda solution or sodium hydroxide in a
stoichiometric ratio and the solution is spray-dried. Similarly to Graham's
salt and sodium diphosphate, pentasodium triphosphate dissolves many
insoluble metal compounds (including lime soaps, etc.). Pentapotassium
CA 02313875 2000-07-14
39
triphosphate, K5P30,o (potassium tripolyphosphate), is marketed for
example in the form of a 50% by weight solution (> 23% P205, 25% K20).
The potassium polyphosphates are widely used in the detergent industry.
Sodium potassium tripolyphosphates, which may also be used in
accordance with the invention, also exist. They are formed for example
when sodium trimetaphosphate is hydrolyzed with KOH:
(NaP03)3 + 2 KOH -~ Na3K2P30~o + H20
According to the invention, they may be used in exactly the same
way as sodium tripolyphosphate, potassium tripolyphosphate or mixtures
thereof. Mixtures of sodium tripolyphosphate and sodium potassium
tripolyphosphate or mixtures of potassium tripolyphosphate and sodium
potassium tripolyphosphate or mixtures of sodium tripolyphosphate and
potassium tripolyphosphate and sodium potassium tripolyphosphate may
also be used in accordance with the invention.
Preferred detergent tablets according to the invention are
characterized in that the basic tablet contains phosphate(s), preferably
alkali metal phosphates) and more preferably pentasodium or
pentapotassium triphosphate (sodium or potassium tripolyphosphate) in
quantities of 20 to 80% by weight, preferably in quantities of 25 to 7%% by
weight and more preferably in quantities of 30 to 70% by weight, based on
the weight of the basic tablet.
Alkalinity sources may be present as further constituents. Alkalinity
sources are, for example, alkali metal hydroxides, alkali metal carbonates,
alkali metal hydrogen carbonates, alkali metal sesquicarbonates, the alkali
metal silicates mentioned, alkali metal metasilicates and mixtures thereof.
According to the present invention, preferred alkalinity sources are the
alkali metal carbonates, more particularly sodium carbonate, sodium
hydrogen carbonate and sodium sesquicarbonate. A builder system
CA 02313875 2000-07-14
containing a mixture of tripolyphosphate and sodium carbonate is
particularly preferred, as is a builder system containing a mixture of
tripolyphosphate and sodium carbonate and sodium disilicate.
In particularly preferred detergent tablets, the basic tablet contains
5 carbonates) andlor hydrogen carbonate(s), preferably alkali metal
carbonates and more preferably sodium carbonate, in quantities of 5 to
50% by weight, preferably in quantities of 7.5 to 40% by weight and more
preferably in quantities of 10 to 30% by weight, based on the weight of the
basic tablet.
10 Organic cobuilders suitable for use in the detergent tablets
according to the invention are, in particular, polycarboxylateslpolycarboxylic
acids, polymeric polycarboxylates, aspartic acid, polyacetals, dextrins,
other organic cobuilders (see below) and phosphonates. These classes of
substances are described in the following.
15 Useful organic builders are, for example, the polycarboxylic acids
usable, for example, in the form of their sodium salts, polycarboxylic acids
in this context being understood to be carboxylic acids which bear more
than one acid function. Examples of such carboxylic acids are citric acid,
adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, malefic
acid,
20 fumaric acid, sugar acids, aminocarboxylic acids, nitrilotriacetic acid
(NTA),
providing its use is not ecologically unsafe, and mixtures thereof. Preferred
salts are the salts of the polycarboxylic acids, such as citric acid, adipic
acid, succinic acid, glutaric acid, tartaric acid, sugar acids and mixtures
thereof.
25 The acids per se may also be used. Besides their builder effect, the
acids also typically have the property of an acidifying component and,
hence, also serve to establish a relatively low and mild pH value in
detergents. Citric acid, succinic acid, glutaric acid, adipic acid, gluconic
acid and mixtures thereof are particularly mentioned in this regard.
30 Other suitable builders are polymeric polycarboxylates such as, for
CA 02313875 2000-07-14
41
example, the alkali metal salts of polyacrylic or polymethacrylic acid, for
- example those with a relative molecular weight of 500 to 70,000 g/mole.
The molecular weights mentioned in this specification for polymeric
polycarboxylates are weight-average molecular weights MW of the particular
acid form which, basically, were determined by gel permeation
chromatography (GPC) using a UV detector. The measurement was
carried out against an external polyacrylic acid standard which provides
realistic molecular weight values by virtue of its structural similarity to
the
polymers investigated. These values differ distinctly from the molecular
weights measured against polystyrene sulfonic acids as standard. The
molecular weights measured against polystyrene sulfonic acids are
generally higher than the molecular weights mentioned in this specification.
Particularly suitable polymers are polyacrylates which preferably
have a molecular weight of 2,000 to 20,000 g/mole. By virtue of their
superior solubility, preferred representatives of this group are the short-
chain polyacrylates which have molecular weights of 2,000 to 10,000
glmole and, more particularly, 3,000 to 5,000 glmole.
Also suitable are copolymeric polycarboxylates, particularly those of
acrylic acid with methacrylic acid and those of acrylic acid or methacrylic
acid with malefic acid. Acrylic acidlmaleic acid copolymers containing 50 to
90% by weight of acrylic acid and 50 to 10% by weight of malefic acid have
proved to be particularly suitable. Their relative molecular weights, based
on the free acids, are generally in the range from 2,000 to 70,000 g/mole,
preferably in the range from 20,000 to 50,000 glmole and more preferably
in the range from 30,000 to 40,000 glmole.
The (co)polymeric polycarboxylates may be used either in powder
form or in the form of an aqueous solution. The content of (co)polymeric
polycarboxylates in the detergent is preferably from 0.5 to 20% by weight
and more preferably from 3 to 10% by weight.
In order to improve solubility in water, the polymers may also contain
- CA 02313875 2000-07-14
42
allyl sulfonic acids such as, for example, allyloxybenzene sulfonic acid and
methallyl sulfonic acid, as monomer.
Other particularly preferred polymers are biodegradable polymers of
more than two different monomer units, for example those which contain
salts of acrylic acid and malefic acid and vinyl alcohol or vinyl alcohol
derivatives as monomers or those which contain salts of acrylic acid and 2-
alkylallyl sulfonic acid and sugar derivatives as monomers.
Other preferred copolymers are those which are described in
German patent applications DE-A-43 03 320 and DE-A-44 17 734 and
which preferably contain acrolein and acrylic acidlacrylic acid salts or
acrolein and vinyl acetate as monomers.
Other preferred builders are polymeric aminodicarboxylic acids, salts
or precursors thereof. Particular preference is attributed to polyaspartic
acids or salts and derivatives thereof which, according to German patent
application DE-A-195 40 086, are also said to have a bleach-stabilizing
effect in addition to their co-builder properties.
Other suitable builders are polyacetals which may be obtained by
reaction of dialdehydes with polyol carboxylic acids containing 5 to 7
carbon atoms and at least 3 hydroxyl groups. Preferred polyacetals are
obtained from dialdehydes, such as glyoxal, glutaraldehyde, terephthal-
aldehyde and mixtures thereof and from polyol carboxylic acids, such as
gluconic acid and/or glucoheptonic acid.
Other suitable organic builders are dextrins, for example oligomers
or polymers of carbohydrates which may be obtained by partial hydrolysis
of starches. The hydrolysis may be carried out by standard methods, for
example acid- or enzyme-catalyzed methods. The end products are
preferably hydrolysis products with average molecular weights of 400 to
500,000 glmole. A polysaccharide with a dextrose equivalent (DE) of 0.5 to
40 and, more particularly, 2 to 30 is preferred, the DE being an accepted
measure of the reducing effect of a polysaccharide by comparison with
_ CA 02313875 2000-07-14
' 43
dextrose which has a DE of 100. Both maltodextrins with a DE of 3 to 20
and dry glucose sirups with a DE of 20 to 37 and also so-called yellow
dextrins and white dextrins with relatively high molecular weights of 2,000
to 30,000 glmole may be used.
The oxidized derivatives of such dextrins are their reaction products
with oxidizing agents which are capable of oxidizing at least one alcohol
function of the saccharide ring to the carboxylic acid function. Dextrins thus
oxidized and processes for their production are known, for example, from
European patent applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0
472 042 and EP-A-0 542 496 and from International patent applications
WO 92118542, WO 93/08251, WO 93!16110, WO 94128030, WO 95!07303,
WO 95112619 and WO 95!20608. An oxidized oligosaccharide
corresponding to German patent application DE-A-196 00 018 is also
suitable. A product oxidized at C6 of the saccharide ring can be particularly
advantageous.
Other suitable co-builders are oxydisuccinates and other derivatives
of disuccinates, preferably ethylenediamine disuccinate. Ethylenediamine-
N,N'-disuccinate (EDDS) is preferably used in the form of its sodium or
magnesium salts. Glycerol disuccinates and glycerol trisuccinates are also
preferred in this connection. The quantities used in zeolite-containing
andlor silicate-containing formulations are from 3 to 15% by weight.
Other useful organic co-builders are, for example, acetylated
hydroxycarboxylic acids and salts thereof which may optionally be present
in lactone form and which contain at least 4 carbon atoms, at least one
hydroxy group and at most two acid groups. Co-builders such as these are
described, for example, in International patent application WO 95120029.
Another class of substances with co-builder properties are the
phosphonates, more particularly hydroxyalkane and aminoalkane phos
phonates. Among the hydroxyalkane phosphonates, 1-hydroxyethane-1,1
diphosphonate (HEDP) is particularly important as a co-builder. It is
CA 02313875 2000-07-14
44
preferably used in the form of the sodium salt, the disodium salt showing a
neutral reaction and the tetrasodium salt an alkaline reaction (pH 9).
Preferred aminoalkane phosphonates are ethylenediamine tetramethylene
phosphonate (EDTMP), diethylenetriamine pentamethylenephosphonate
(DTPMP) and higher homologs thereof. They are preferably used in the
form of the neutrally reacting sodium salts, for example as the hexasodium
salt of EDTMP or as the hepta- and octasodium salts of DTPMP. Of the
phosphonates, HEDP is preferably used as a builder. In addition, the
aminoalkane phosphonates have a pronounced heavy metal binding
capacity. Accordingly, it can be of advantage, particularly where the
detergents also contain bleach, to use aminoalkane phosphonates, more
particularly DTPMP, or mixtures of the phosphonates mentioned.
In addition, any compounds capable of forming complexes with
alkaline earth metal ions may be used as co-builders.
The quantity of builder used is normally between 10 and 70% by
weight, preferably between 15 and 60% by weight and more preferably
between 20 and 50% by weight, based on the basic tablet. The quantity of
builder used is again dependent upon the particular application envisaged,
so that bleach tablets can contain larger quantities of builders (for example
between 20 and 70% by weight, preferably between 25 and 65% by weight
and more preferably between 30 and 55% by weight) than, for example,
laundry detergent tablets (normally 10 to 50% by weight, preferably 12.5 to
45% by weight and more preferably 17.5 to 37.5% by weight).
The above-mentioned substances from the group of builders and co-
builders may of course be part of the compositions present in the cavity.
Preferred detergent tablets additionally contain one or more
surfactant(s). Anionic, nonionic, cationic andlor amphoteric surfactants or
mixtures thereof may be used in the detergent tablets according to the
invention. From the performance perspective, mixtures of anionic and
nonionic surfactants are preferred for laundry detergent tablets while
CA 02313875 2000-07-14
nonionic surfactants are preferred for dishwasher tablets. The total
surfactant content of laundry detergent tablets is between 5 and 60% by
weight and preferably above 15% by weight, based on tablet weight,
whereas dishwasher detergent tablets preferably contain less than 5% by
5 weight of surfactant(s).
The anionic surfactants used are, for example, those of the sulfonate
and sulfate type. Preferred surfactants of the sulfonate type are Cg~3 alkyl
benzenesulfonates, olefin sulfonates, i.e. mixtures of alkene and hydroxy-
alkane sulfonates, and the disulfonates obtained, for example, from C,2_~8
10 monoolefins with an internal or terminal double bond by sulfonation with
gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the
sulfonation products. Other suitable surfactants of the sulfonate type are
the alkane sulfonates obtained from C~2_~$ alkanes, for example by
sulfochlorination or sulfoxidation and subsequent hydrolysis or
15 neutralization. The esters of a-sulfofatty acids (ester sulfonates), for
example the a-sulfonated methyl esters of hydrogenated coconut, palm
kernel or tallow acids, are also suitable.
Other suitable anionic surfactants are sulfonated fatty acid glycerol
esters, i.e. the monoesters, diesters and triesters and mixtures thereof
20 which are obtained where production is carried out by esterification of a
monoglycerol with 1 to 3 moles of fatty acid or in the transesterification of
triglycerides with 0.3 to 2 moles of glycerol. Preferred sulfonated fatty acid
glycerol esters are the sulfonation products of saturated C6_22 fatty acids,
for example caproic acid, caprylic acid, capric acid, myristic acid, lauric
25 acid, palmitic acid, stearic acid or behenic acid.
Preferred alk(en)yl sulfates are the alkali metal salts and, in
particular, the sodium salts of the sulfuric acid semiesters of C~2_~$ fatty
alcohols, for example coconut alcohol, tallow alcohol, lauryl, myristyl, cetyl
or stearyl alcohol, or C~o_2o oxoalcohols and the corresponding semiesters
30 of secondary alcohols with the same chain length. Other preferred
CA 02313875 2000-07-14
46
alk(en)yl sulfates are those with the chain length mentioned which contain
a synthetic, linear alkyl chain based on a petrochemical and which are
similar in their degradation behavior to the corresponding compounds
based on oleochemical raw materials. C~2_~s alkyl sulfates and C~2_~5 alkyl
sulfates and also C~4_~5 alkyl sulfates are particularly preferred from the
washing performance point of view. Other suitable anionic surfactants are
2,3-alkyl sulfates which may be produced, for example, in accordance with
US 3,234,258 or US 5,075,041 and which are commercially obtainable as
products of the Shell Oil Company under the name of DAN~.
The sulfuric acid monoesters of linear or branched C~_2~ alcohols
ethoxylated with 1 to 6 moles of ethylene oxide, such as 2-methyl-branched
C9_i ~ alcohols containing on average 3.5 moles of ethylene oxide (EO) or
C~2_~8 fatty alcohols containing 1 to 4 EO, are also suitable. In view of
their
high foaming capacity, they are normally used in only relatively small
quantities, for example in quantities of 1 to 5% by weight, in dishwashing
detergents.
Other suitable anionic surfactants are the salts of alkyl sulfosuccinic
acid which are also known as sulfosuccinates or as sulfosuccinic acid
esters and which represent monoesters and/or diesters of sulfosuccinic
acid with alcohols, preferably fatty alcohols and, more particularly,
ethoxylated fatty alcohols. Preferred sulfosuccinates contain C~~$ fatty
alcohol molecules or mixtures thereof. Particularly preferred
sulfosuccinates contain a fatty alcohol molecule derived from ethoxylated
fatty alcohols which, considered in isolation, represent nonionic surfactants
(for a description, see below). Of these sulfosuccinates, those of which the
fatty alcohol molecules are derived from narrow-range ethoxylated fatty
alcohols are particularly preferred. Alk(en)yl succinic acid preferably
containing 8 to 18 carbon atoms in the alk(en)yl chain or salts thereof may
also be used.
Other suitable anionic surfactants are, in particular, soaps. Suitable
CA 02313875 2000-07-14
47
soaps are, in particular, saturated fatty acid soaps, such as the salts of
lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic
acid and behenic acid, and soap mixtures derived in particular from natural
fatty acids, for example coconut, palm kernel or tallow acids.
The anionic surfactants, including the soaps, may be present in the
form of their sodium, potassium or ammonium salts and as soluble salts of
organic bases, such as mono-, di- or triethanolamine. The anionic
surfactants are preferably present in the form of their sodium or potassium
salts and, more preferably, in the form of their sodium salts.
Preferred nonionic surfactants are alkoxylated, advantageously
ethoxylated, more especially primary alcohols preferably containing 8 to 18
carbon atoms and, on average, 1 to 12 moles of ethylene oxide (EO) per
mole of alcohol, in which the alcohol group may be linear or, preferably,
methyl-branched in the 2-position or may contain linear and methyl-
branched groups in the form of the mixtures typically present in oxoalcohol
groups. However, alcohol ethoxylates containing linear groups of alcohols
of native origin with 12 to 18 carbon atoms, for example coconut, palm,
tallow or oleyl alcohol, and on average 2 to 8 EO per mole of alcohol are
particularly preferred. Preferred ethoxylated alcohols include, for example,
C~Z_~4 alcohols containing 3 EO or 4 EO, C9_~~ alcohol containing 7 EO,
C~3_~5 alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, C~2_~8 alcohols
containing 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of
C~2_~4 alcohol containing 3 EO and 02_18 alcohol containing 5 EO. The
degrees of ethoxylation mentioned represent statistical mean values which,
for a special product, can be a whole number or a broken number.
Preferred alcohol ethoxylates have a narrow homolog distribution (narrow
range ethoxylates, NRE). In addition to these nonionic surfactants, fatty
alcohols containing more than 12 EO may also be used, examples
including tallow fatty alcohol containing 14 EO, 25 EO, 30 EO or 40 EO.
Suitable other nonionic surfactants are alkyl glycosides with the
- CA 02313875 2000-07-14
48
general formula RO(G)X where R is a primary, linear or methyl-branched,
more particularly 2-methyl-branched, aliphatic radical containing 8 to 22
and preferably 12 to 18 carbon atoms and G stands for a glycose unit
containing 5 or 6 carbon atoms, preferably glucose. The degree of
oligomerization x, which indicates the distribution of monoglycosides and
oligoglycosides, is a number of 1 to 10 and preferably 1.2 to 1.4.
Another class of preferred nonionic surfactants which may be used
either as sole nonionic surfactant or in combination with other nonionic
surfactants are alkoxylated, preferably ethoxylated or ethoxylated and
propoxylated, fatty acid alkyl esters preferably containing 1 to 4 carbon
atoms in the alkyl chain, more especially the fatty acid methyl esters which
are described, for example, in Japanese patent application JP 581217598
or which are preferably produced by the process described in International
patent application WO-A-90113533.
Nonionic surfactants of the amine oxide type, for example N-
coconutalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxy-
ethylamine oxide, and the fatty acid alkanolamide type are also suitable.
The quantity in which these nonionic surfactants are used is preferably no
more than the quantity in which the ethoxylated fatty alcohols are used
and, more preferably, no more than half that quantity.
Other suitable surfactants are polyhydroxyfatty acid amides
corresponding to formula (X):
R'
R-CO-N-[Z] ()()
in which RCO is an aliphatic acyl group containing 6 to 22 carbon atoms,
R' is hydrogen, an alkyl or hydroxyalkyl group containing 1 to 4 carbon
atoms and [Z] is a linear or branched polyhydroxyalkyl group containing 3
to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxyfatty acid
amides are known substances which may normally be obtained by
CA 02313875 2000-07-14
49
reductive amination of a reducing sugar with ammonia, an alkylamine or an
alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl
ester or a fatty acid chloride.
The group of polyhydroxyfatty acid amides also includes compounds
corresponding to formula (XI):
R'-O-R2
R-CO-N-[Z] (XI )
in which R is a linear or branched alkyl or alkenyl group containing 7 to 12
carbon atoms, R' is a linear, branched or cyclic alkyl group or an aryl group
containing 2 to 8 carbon atoms and R2 is a linear, branched or cyclic alkyl
group or an aryl group or an oxyalkyl group containing 1 to 8 carbon atoms,
C~~ alkyl or phenyl groups being preferred, and [Z] is a linear polyhydroxy-
alkyl group, of which the alkyl chain is substituted by at least two hydroxyl
groups, or alkoxylated, preferably ethoxylated or propoxylated, derivatives
of that group.
[Z] is preferably obtained by reductive amination of a reduced sugar,
for example glucose, fructose, maltose, lactose, galactose, mannose or
xylose. The N-alkoxy- or N-aryloxy-substituted compounds may then be
converted into the required polyhydroxyfatty acid amides by reaction with
fatty acid methyl esters in the presence of an alkoxide as catalyst, for
example in accordance with the teaching of International patent application
WO-A-95107331.
According to the invention, preferred detergent tablets are those
containing anionic and nonionic surfactant(s). Performance-related
advantages can arise out of certain quantity ratios in which the individual
classes of surfactants are used.
For example, particularly preferred detergent tablets are charac-
terized in that the ratio of anionic surfactants) to nonionic surfactants) is
CA 02313875 2000-07-14
from 10:1 to 1:10, preferably from 7.5:1 to 1:5 and more preferably from 5:1
to 1:2. Other preferred detergent tablets contain surfactant(s), preferably
anionic andlor nonionic surfactant(s), in quantities of 5 to 40% by weight,
preferably 7.5 to 35% by weight, more preferably 10 to 30% by weight and
5 most preferably 12.5 to 25% by weight, based on the weight of the tablet.
It can be of advantage from the performance point of view if certain
classes of surfactants are missing from certain phases of the detergent
tablets or from the entire tablet, i.e. from every phase. In another important
embodiment of the present invention, therefore, at least one phase of the
10 tablets is free from nonionic surfactants.
Conversely, a positive effect can also be obtained through the
presence of certain surfactants in individual phases or in the tablet as a
whole, i.e. in every phase. Introducing the alkyl polyglycosides described
above has proved to be of particular advantage, so that detergent tablets in
15 which at least one phase of the tablet contains alkyl polyglycosides are
preferred.
As with the nonionic surfactants, the omission of anionic surfactants
from individual phases or from all phases can result in detergent tablets
which are more suitable for certain applications. Accordingly, detergent
20 tablets where at least one phase of the tablet is free from anionic
surfactants are also possible in accordance with the present invention.
As already mentioned, the use of surfactants in dishwasher tablets is
preferably confined to the use of nonionic surfactants in small quantities.
Detergent tablets preferably used as dishwasher tablets in accordance with
25 the invention are characterized in that the basic tablet has total
surfactant
contents below 5% by weight, preferably below 4% by weight, more
preferably below 3% by weight and most preferably below 2% by weight,
based on the weight of the basic tablet. Normally, the only surfactants
used in dishwasher detergents are low-foaming nonionic surfactants.
30 Representatives from the groups of anionic, cationic or amphoteric
~
CA 02313875 2000-07-14
51
surfactants are of lesser importance. In one particularly preferred
embodiment, the dishwasher detergent tablets according to the invention
contain nonionic surfactants, more particularly nonionic surfactants from
the group of alkoxylated alcohols. Preferred nonionic surfactants are
alkoxylated, advantageously ethoxylated, more especially primary alcohols
preferably containing 8 to 18 carbon atoms and, on average, 1 to 12 moles
of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical may
be linear or, preferably, methyl-branched in the 2-position or may contain
linear and methyl-branched radicals in the form of the mixtures typically
present in oxoalcohol radicals. However, alcohol ethoxylates containing
linear radicals of alcohols of native origin with 12 to 18 carbon atoms, for
example coconut oil, palm oil, tallow or oleyl alcohol, and on average 2 to 8
EO per mole of alcohol are particularly preferred. Preferred ethoxylated
alcohols include, for example, C,Z-14 alcohols containing 3 EO or 4 EO,
C~~1 alcohol containing 7 EO, C~3_~5 alcohols containing 3 EO, 5 EO, 7 EO
or 8 EO, C~2_~8 alcohols containing 3 EO, 5 EO or 7 EO and mixtures
thereof, such as mixtures of C~2-~4 alcohol containing 3 EO and C~2-~$
alcohol containing 5 EO. The degrees of ethoxylation mentioned represent
statistical mean values which, for a special product, can be a whole number
or a broken number. Preferred alcohol ethoxylates have a narrow homolog
distribution (narrow range ethoxylates, NRE). In addition to these nonionic
surfactants, fatty alcohols containing more than 12 EO may also be used,
examples including tallow fatty alcohol containing 14 EO, 25 EO, 30 EO or
40 EO.
In a particularly preferred embodiment of the production of laundry
or dishwasher detergent tablets according to the invention, the laundryl
dishwasher detergent tablets contain a nonionic surtactant which has a
melting point above room temperature. Accordingly, at least one of the
tablettable compositions used in the process according to the invention
preferably contains a nonionic surfactant with a melting point above
20°C.
CA 02313875 2000-07-14
52
Preferred nonionic surfactants have melting points above 25°C while
particularly preferred nonionic surfactants have melting points between 25
and 60°C and, more particularly, between 26.6 and 43.3°C.
Suitable nonionic surfactants with melting or softening points in the
temperature range mentioned above are, for example, low-foaming
nonionic surfactants which may be solid or highly viscous at room
temperature. If nonionic surfactants highly viscous at room temperature
are used, they preferably have a viscosity above 20 Pas, more preferably
above 35 Pas and most preferably above 40 Pas. Nonionic surfactants
which are wax-like in consistency at room temperature are also preferred.
Nonionic surfactants solid at room temperature preferably used in
accordance with the invention belong the groups of alkoxylated nonionic
surfactants, more particularly ethoxylated primary alcohols, and mixtures of
these surfactants with structurally complex surfactants, such as polyoxy-
propylenelpolyoxyethylenelpolyoxypropylene (POIEO/PO) surfactants. In
addition, (POIEOIPO) nonionic surfactants are distinguished by good foam
control.
In one preferred embodiment of the present invention, the nonionic
surfactant with a melting point above room temperature is an ethoxylated
nonionic surfactant emanating from the reaction of a monohydroxyalkanol
or alkylphenol containing 6 to 20 carbon atoms with preferably at least 12
moles, more preferably at least 15 moles and most preferably at least 20
moles of ethylene oxide per mole of alcohol or alkylphenol.
A particularly preferred nonionic surfactant solid at room tempera
ture is obtained from a straight-chain fatty alcohol containing 16 to 20
carbon atoms (Cl~2o alcohol), preferably a C~8 alcohol, and at least 12
moles, preferably at least 15 moles and more preferably at least 20 moles
of ethylene oxide. Of these nonionic surfactants, the so-called narrow
range ethoxylates (see above) are particularly preferred.
The nonionic surfactant solid at room temperature preferably also
CA 02313875 2000-07-14
53
contains propylene oxide units in the molecule. These PO units preferably
make up as much as 25% by weight, more preferably as much as 20% by
weight and, most preferably, up to 15% by weight of the total molecular
weight of the nonionic surfactant. Particularly preferred nonionic
surfactants are ethoxylated monohydroxyalkanols or alkylphenols which
additionally contain polyoxyethylenelpolyoxypropylene block copolymer
units. The alcohol or alkylphenol component of these nonionic surfactant
molecules preferably makes up more than 30% by weight, more preferably
more than 50% by weight and most preferably more than 70% by weight of
the total molecular weight of these nonionic surfactants.
Other particularly preferred nonionic surfactants with melting points
above room temperature contain 40 to 70% of a polyoxypropylenelpolyoxy-
ethylene/polyoxpropylene block polymer blend which contains 75% by
weight of an inverted block copolymer of polyoxyethylene and polyoxypro-
pylene with 17 moles of ethylene oxide and 44 moles of propylene oxide
and 25% by weight of a block copolymer of polyoxyethylene and polyoxy-
propylene initiated with trimethylol propane and containing 24 moles of
ethylene oxide and 99 moles of propylene oxide per mole of trimethylol
propane.
Nonionic surfactants which may be used with particular advantage
are obtainable, for example, under the name of Poly Tergent~ SLF-18 from
Olin Chemicals.
Another preferred surfactant may be described by the following
formula:
R' O[CH2CH(CH3)O]x[CH2CH20]y[CH2CH(OH)R2j
in which R' is a linear or branched aliphatic hydrocarbon radical containing
4 to 18 carbon atoms or mixtures thereof, R2 is a linear or branched
hydrocarbon radical containing 2 to 26 carbon atoms or mixtures thereof, x
- CA 02313875 2000-07-14
54
has a value of 0.5 to 1.5 and y has a value of at least 15.
Other preferred nonionic surfactants are the end-capped poly(oxy-
alkylated) nonionic surfactants corresponding to the following formula:
R' O[CH2CH(R3)O]X(CH2]kCH(OH)[CH2]~OR2
in which R' and R2 are linear or branched, saturated or unsaturated,
aliphatic or aromatic hydrocarbon radicals containing 1 to 30 carbon atoms,
R3 stands for H or for a methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl
or
2-methyl-2-butyl radical, x has a value of 1 to 30, k and j have values of 1
to 12 and preferably 1 to 5. Where x has a value of >_ 2, each substituent
R3 in the above formula may be different. R' and R2 are preferably linear
or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon
radicals containing 6 to 22 carbon atoms, radicals containing 8 to 18
carbon atoms being particularly preferred. For the substituent R3, H, -CH3
or CH2CH3 are particularly preferred. Particularly preferred values for x
are in the range from 1 to 20 and more particularly in the range from 6 to
15.
As mentioned above, each substituent R3 in the above formula may
be different where x is >_ 2. In this way, the alkylene oxide unit in the
square brackets can be varied. If, for example, x has a value of 3, the
substituent R3 may be selected to form ethylene oxide (R3 = H) or
propylene oxide (R3 = CH3) units which may be joined together in any
order, for example (EO)(PO)(EO), (EO)(EO)(PO), (EO)(EO)(EO),
(PO)(EO)(PO), (PO)(PO)(EO) and (PO)(PO)(PO). The value 3 for x was
selected by way of example and may easily be larger, the range of variation
increasing with increasing x-values and including, for example, a large
number of (EO) groups combined with a small number of (PO) groups or
vice versa.
Particularly preferred end-capped poly(oxyalkylated) alcohols
- CA 02313875 2000-07-14
55
corresponding to the above formula have values for both k and j of 1, so
that the above formula can be simplified to:
R'O[CH2CH(R3)O]XCH2CH(OH)CH20R2
In this formula, R', RZ and R3 are as defined above and x has a value of 1
to 30, preferably 1 to 20 and more preferably 6 to 18. Surfactants in which
the substituents R' and R2 have 9 to 14 carbon atoms, R3 stands for H and
x has a value of 6 to 15 are particularly preferred.
In order to facilitate the disintegration of heavily compacted tablets,
disintegration aids, so-called tablet disintegrators, may be incorporated in
the basic tablets to shorten their disintegration times. According to Rbmpp
(9th Edition, Vol. 6, page 4440) and Voigt "Lehrbuch der pharma-
zeutischen Technologie" (6th Edition, 1987, pages 182-184), tablet
disintegrators or disintegration accelerators are auxiliaries which promote
the rapid disintegration of tablets in water or gastric juices and the release
of the pharmaceuticals in an absorbable form.
These substances, which are also known as "disintegrators" by
virtue of their effect, are capable of undergoing an increase in volume on
contact with water so that, on the one hand, their own volume is increased
(swelling) and, on the other hand, a pressure can be generated through the
release of gases which causes the tablet to disintegrate into relatively small
particles. Well-known disintegrators are, for example, carbonatelcitric acid
systems, although other organic acids may also be used. Swelling
disintegration aids are, for example, synthetic polymers, such as polyvinyl
pyrrolidone (PVP), or natural polymers and modified natural substances,
such as cellulose and starch and derivatives thereof, alginates or casein
derivatives.
Preferred detergent tablets contain 0.5 to 10% by weight, preferably
3 to 7% by weight and more preferably 4 to 6% by weight of one or more
' CA 02313875 2000-07-14
56
disintegration aids, based on the weight of the tablet. If only the basic
tablet contains disintegration aids, the figures mentioned are based solely
on the weight of the basic tablet.
According to the invention, preferred disintegrators are cellulose-
based disintegrators, so that preferred detergent tablets contain a
cellulose-based disintegrator in quantities of 0.5 to 10% by weight,
preferably 3 to 7% by weight and more preferably 4 to 6% by weight. Pure
cellulose has the formal empirical composition (C6H~pO5)n and, formally, is
a ~i-1,4-polyacetal of cellobiose which, in turn, is made up of two molecules
of glucose. Suitable celluloses consist of ca. 500 to 5000 glucose units
and, accordingly, have average molecular weights of 50,000 to 500,000.
According to the invention, cellulose derivatives obtainable from cellulose
by polymer-analog reactions may also be used as cellulose-based
disintegrators. These chemically modified celluloses include, for example,
products of esterification or etherification reactions in which hydroxy
hydrogen atoms have been substituted. However, celluloses in which the
hydroxy groups have been replaced by functional groups that are not
attached by an oxygen atom may also be used as cellulose derivatives.
The group of cellulose derivatives includes, for example, alkali metal
celluloses, carboxymethyl cellulose (CMC), cellulose esters and ethers and
aminocelluloses. The cellulose derivatives mentioned are preferably not
used on their own, but rather in the form of a mixture with cellulose as
cellulose-based disintegrators. The content of cellulose derivatives in
mixtures such as these is preferably below 50% by weight and more
preferably below 20% by weight, based on the cellulose-based
disintegrator. In one particularly preferred embodiment, pure cellulose free
from cellulose derivatives is used as the cellulose-based disintegrator.
The cellulose used as disintegration aid is preferably not used in
fine-particle form, but is converted into a coarser form, for example by
granulation or compacting, before it is added to and mixed with the
CA 02313875 2000-07-14
57
premixes to be tabletted. Detergent tablets which contain granular or
optionally co-granulated disintegrators are described in German patent
applications DE 197 09 991 (Stefan Herzog) and DE 197 10 254 (Henkel)
and in International patent application WO 98!40463 (Henkel). Further
particulars of the production of granulated, compacted or co-granulated
cellulose disintegrators can also be found in these patent applications. The
particle sizes of such disintegration aids is mostly above 200 pm,
preferably at least 90% by weight of the particles being between 300 and
1600 Nm in size and, more particularly, between 400 and 1200 Nm in size.
According to the invention, the above-described relatively coarse-particle
cellulose-based disintegrators described in detail in the cited patent
applications are preferably used as disintegration aids and are
commercially obtainable, for example under the name of Arbocel~ TF-30-
HG from Rettenmaier.
Microcrystalline cellulose may be used as another cellulose-based
disintegration aid or as part of such a component. This microcrystalline
cellulose is obtained by partial hydrolysis of the celluloses under conditions
which only attack and completely dissolve the amorphous regions (ca. 30%
of the total cellulose mass) of the celluloses, but leave the crystalline
regions (ca. 70%) undamaged. Subsequent de-aggregation of the
microfine celluloses formed by hydrolysis provides the microcrystalline
celluloses which have primary particle sizes of ca. 5 Nm and which can be
compacted, for example, to granules with a mean particle size of 200 Nm.
According to the invention, preferred detergent tablets aditionally
contain a disintegration aid, preferably a cellulose-based disintegration aid,
preferably in granular, co-granulated or compacted form, in quantities of 0.5
to 10% by weight, preferably in quantities of 3 to 7% by weight and more
preferably in quantities of 4 to 6% by weight, based on tablet weight.
The detergent tablets according to the invention may additionally a
gas-evolving effervescent system both in the basic tablet and in the cavity.
' CA 02313875 2000-07-14
58
The gas-evolving effervescent system may consist of a single substance
which releases a gas on contact with water. Among these compounds,
particular mention is made of magnesium peroxide which releases oxygen
on contact with water. However, the gas-releasing effervescent system
normally consists of at least two constituents which react with one another
to form a gas. Although various possible systems could be used, for
example systems releasing nitrogen, oxygen or hydrogen, the effervescent
system used in the detergent tablets according to the invention should be
selected with both economic and ecological considerations in mind.
Preferred effervescent systems consist of alkali metal carbonate andlor
hydrogen carbonate and an acidifying agent which is capable of releasing
carbon dioxide from the alkali metal salts in aqueous solution.
Among the alkali metal carbonates and hydrogen carbonates, the
sodium and potassium salts are preferred to the other salts for reasons of
cost. The pure alkali metal carbonates and hydrogen carbonates do not of
course have to be used, instead mixtures of different carbonates and
hydrogen carbonates may be preferred.
In preferred detergent tablets, 2 to 20% by weight, preferably 3 to
15% by weight and more preferably 5 to 10% by weight of an alkali metal
carbonate or hydrogen carbonate and 1 to 15% by weight, preferably 2 to
12% by weight and more preferably 3 to 10% by weight of an acidifying
agent, based on the tablet as a whole, are used as the effervescent
system.
Suitable acidifying agents which release carbon dioxide from the
alkali metal salts in aqueous solution are, for example, boric acid and alkali
metal hydrogen sulfates, alkali metal dihydrogen phosphates and other
inorganic salts. However, organic acidifying agents are preferably used,
citric acid being a particularly preferred acidifying agent. However, other
solid mono-, oligo- and polycarboxylic acids in particular may also be used.
Within this group, tartaric acid, succinic acid, malonic acid, adipic acid,
' CA 02313875 2000-07-14
59
malefic acid, fumaric acid, oxalic acid and polyacrylic acid are preferred.
Organic sulfonic acids, such as amidosulfonic acid, may also be used.
Sokalan~ DCS (trademark of BASF), a mixture of succinic acid (max. 31
by weight), glutaric acid (max. 50% by weight) and adipic acid (max. 33%
by weight), is commercially obtainable and may also be used with
advantage as an acidifying agent for the purposes of the present invention.
According to the invention, preferred detergent tablets are those in
which a substance selected from the group of organic di-, tri- and
oligocarboxylic acids or mixtures thereof is present as the acidifying agent
in the effervescent system.
Among the compounds yielding H202 in water which serve as
bleaching agents, sodium perborate tetrahydrate and sodium perborate
monohydrate are particularly important. Other useful bleaching agents are,
for example, sodium percarbonate, peroxypyrophosphates, citrate perhy-
drates and H202-yielding peracidic salts or peracids, such as
perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or
diperdodecane dioic acid. Dishwasher detergents according to the
invention may also containbleaching agents from the group of organic
bleaches. Typical organic bleaching agents are diacyl peroxides, such as
dibenzoyl peroxide for example. Other typical organic bleaching agents are
the peroxy acids, of which alkyl peroxy acids and aryl peroxy acids are
particularly mentioned as examples. Preferred representatives are (a)
peroxybenzoic acid and ring-substituted derivatives thereof, such as alkyl
peroxybenzoic acids, but also peroxy-a-naphthoic acid and magnesium
monoperphthalate, (b) aliphatic or substituted aliphatic peroxy acids, such
as peroxylauric acid, peroxystearic acid, s-phthalimidoperoxycaproic acid
[phthaloiminoperoxyhexanoic acid (PAP)], o-carboxybenzamidoperoxy-
caproic acid, N-nonenylamidoperadipic acid and N-nonenylamido-
persuccinates and (c) aliphatic and araliphatic peroxydicarboxylic acids,
such as 1,12-diperoxycarboxylic acid, 1,9-diperoxyazelaic acid, diperoxy-
CA 02313875 2000-07-14
sebacic acid, diperoxybrassylic acid, diperoxyphthalic acids, 2-decyldi-
peroxybutane-1,4-dioic acid, N,N-terephthaloyl-di(6-aminopercaproic acid).
Other suitable bleaching agents in dishwasher tablets according to
the invention are chlorine- and bromine-releasing substances. Suitable
5 chlorine- or bromine-releasing materials are, for example, heterocyclic N-
bromamides and N-chloramides, for example trichloroisocyanuric acid,
tribromoisocyanuric acid, dibromoisocyanuric acid andlor dichloro-
isocyanuric acid (DICA) andlor salts thereof with cations, such as
potassium and sodium. Hydantoin compounds, such as 1,3-dichloro-5,5
10 dimethyl hydantoin, are also suitable.
The bleaching agents are used in dishwasher detergents in
quantities of normally 1 to 30% by weight, preferably 2.5 to 20% by weight
and more preferably 5 to 15% by weight, based on the detergent. In the
context of the present invention, these quantities are based on the weight
15 of the basic tablet.
Bleach activators which support the effect of the bleaching agents
can also be part of the basic tablet. Known bleach activators are
compounds which contain one or more N- or O-acyl groups, such as
substances from the class of anhydrides, esters, imides and acylated
20 imidazoles or oximes. Examples are tetraacetyl ethylenediamine (TAED),
tetraacetyl methylenediamine (TAMD) and tetraacetyl hexylenediamine
(TAHD) and also pentaacetyl glucose (PAG), 1,5-diacetyl-2,2-
dioxohexaydro-1,3,5-triazine (DADHT) and isatoic anhydride (ISA).
Suitable bleach activators are compounds which form aliphatic
25 peroxocarboxylic acids containing preferably 1 to 10 carbon atoms and
more preferably 2 to 4 carbon atoms andlor optionally substituted
perbenzoic acid under perhydrolysis conditions. Substances bearing O
andlor N-acyl groups with the number of carbon atoms mentioned andlor
optionally substituted benzoyl groups are suitable. Preferred bleach
30 activators are polyacylated alkylenediamines, more particularly tetraacetyl
' CA 02313875 2000-07-14
61
ethylenediamine (TAED), acylated triazine derivatives, more particularly
1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycol-
urils, more particularly tetraacetyl glycoluril (TAGU), N-acylimides, more
particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates,
more particularly n-nonanoyl- or isononanoyl-oxybenzenesulfonate (n- or
iso-NOBS), carboxylic anhydrides, more particularly phthalic anhydride,
acylated polyhydric alcohols, more particularly triacetin, ethylene glycol
diacetate, 2,5-diacetoxy-2,5-dihydrofuran, n-methyl morpholinium
acetonitrile methyl sulfate (MMA) and the enol esters known from German
patent applications DE 196 16 693 and DE 196 16 767, acetylated sorbitol
and mannitol and the mixtures thereof (SORMAN), acylated sugar
derivatives, more particularly pentaacetyl glucose (PAG), pentaacetyl
fructose, tetraacetyl xylose and octaacetyl lactose, and acetylated,
optionally N-alkylated glucamine and gluconolactone, andlor N-acylated
lactams, for example N-benzoyl caprolactam. Substituted hydrophilic acyl
acetals are also preferably used. Combinations of conventional bleach
activators may also be used. The bleach activators are normally used in
dishwasher detergents in quantities of 0.1 to 20% by weight, preferably in
quantities of 0.25 to 15% by weight and most preferably in quantities of 1 to
10% by weight, based on the detergent as a whole. In the context of the
invention, the quantities mentioned are based on the weight of the basic
tablet.
In addition to or instead of the conventional bleach activators
mentioned above, so-called bleach catalysts may also be incorporated in
the active substance particles. These substances are bleach-boosting
transition metal salts or transition metal complexes such as, for example,
manganese-, iron-, cobalt-, ruthenium- or molybdenum-salen or -carbonyl
complexes. Manganese, iron, cobalt, ruthenium, molybdenum, titanium,
vanadium and copper complexes with nitrogen-containing tripod ligands
and cobalt-, iron-, copper- and ruthenium-ammine complexes may also be
CA 02313875 2000-07-14
62
used as bleach catalysts.
Bleach activators from the group of polyacylated alkylenediamines,
more particularly tetraacetyl ethylenediamine (TAED), N-acyl imides, more
particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates,
more particularly n-nonanoyl- or isononanoyl-oxybenzenesulfonate (n- or
iso-NOBS), n-methyl morpholinium acetonitrile methyl sulfate (MMA) are
preferably used, preferably in quantities of up to 10% by weight, more
preferably in quantities of 0.1 % by weight to 8% by weight, most preferably
in quantities of 2 to 8% by weight and, with particular advantage, in
quantities of 2 to 6% by weight, based on the detergent as a whole.
Bleach-boosting transition metal complexes, more particularly
containing the central atoms Mn, Fe, Co, Cu, Mo, V, Ti andlor Ru,
preferably selected from the group of manganese andlor cobalt salts and/or
complexes, more preferably the cobalt (ammine) complexes, cobalt
(acetate) complexes, cobalt (carbonyl) complexes, chlorides of cobalt or
manganese and manganese sulfate, are also present in typical quantities,
preferably in a quantity of up to 5% by weight, more preferably in a quantity
of 0.0025% by weight to 1 % by weight and most preferably in a quantity of
0.01 % by weight to 0.25% by weight, based on the detergent as a whole.
In special cases, however, more bleach activator may even be used.
Detergent tablets which are characterized in that the basic tablet
contains bleaching agents from the group of oxygen or halogen bleaching
agents, more particularly chlorine bleaching agents, preferably sodium
peborate and sodium percarbonate, in quantities of 2 to 25% by weight,
preferably 5 to 20% by weight and more preferably 10 to 15% by weight,
based on the weight of the basic tablet, represent a preferred embodiment
of the present invention.
In another preferred embodiment, the basic tablet andlor the active
substances) in the cavity contain bleach activators. Detergent tablets in
which the basic tablet contains bleach activators from the groups of
. CA 02313875 2000-07-14
63
polyacylated alkylenediamines, more particularly tetraacetyl ethylene-
diamine (TAED), N-acyl imides, more particularly N-nonanoyl succinimide
(NOSI), acylated phenol sulfonates, more particularly n-nonanoyl- or
isononanoyl-oxybenzenesulfonate (n- or iso-NOBS), n-methyl
morpholinium acetonitrile methyl sulfate (MMA), in quantities of 0.25 to
15% by weight, preferably in quantities of 0.5% by weight to 10% by weight
and more preferably in quantities of 1 to 5% by weight, based on the weight
of the basic tablet, are also preferred.
To protect the tableware or the machine itself, the detergent tablets
according to the invention may contain corrosion inhibitors, especially in the
basic tablet, silver protectors being particularly important for dishwashing
machines. Known corrosion inhibitors may be used. Above all, silver
protectors selected from the group of triazoles, benzotriazoles,
bisbenzotriazoles, aminotriazoles, alkylaminotriazoles and the transition
metal salts or complexes may generally be used. Benzotriazole andlor
alkylaminotriazole islare particularly preferred. In addition, dishwashing
formulations often contain corrosion inhibitors containing active chlorine
which are capable of distinctly reducing the corrosion of silver surfaces.
Chlorine-free dishwashing detergents contain in particular oxygen- and
nitrogen-containing organic redox-active compounds, such as dihydric and
trihydric phenols, for example hydroquinone, pyrocatechol, hydroxy-
hydroquinone, gallic acid, phloroglucinol, pyrogallol and derivatives of
these compounds. Salt-like and complex-like inorganic compounds, such
as salts of the metals Mn, Ti, Zr, Hf, V, Co and Ce are also frequently used.
Of these, the transition metal salts selected from the group of manganese
and/or cobalt salts andlor complexes are preferred, cobalt(ammine)
complexes, cobalt(acetate) complexes, cobalt(carbonyl) complexes,
chlorides of cobalt or manganese and manganese sulfate being particularly
preferred. Zinc compounds may also be used to prevent corrosion of
tableware.
CA 02313875 2000-07-14
64
In preferred detergent tablets according to the invention, the basic
tablet contains silver corrosion inhibitors from the group of triazoles,
benzotriazoles, bisbenzotriazoles, aminotriazoles, alkylaminotriazoles and
the transition metal salts or complexes, preferably benzotriazole andlor
alkyl aminotriazole, in quantities of 0.01 to 5% by weight, preferably in
quantities of 0.05 to 4% by weight and more preferably in quantities of 0.5
to 3% by weight, based on the weight of the basic tablet.
However, the cavity filling may of course also contain silver
corrosion inhibitors, in which case the basic tablet may also contain silver
corrosion inhibitors or may be free from such compounds.
Besides the ingredients mentioned above, other classes of
substances are suitable for incorporation in detergents. Thus, detergent
tablets in which the basic tablet additionally contains one or more
substances from the groups of enzymes, corrosion inhibitors, film inhibitors,
co-builders, dyes andlor perfumes in total quantities of 6 to 30% by weight,
preferably 7.5 to 25% by weight and more preferably 10 to 20% by weight,
based on the weight of the basic tablet, are preferred.
Besides the constituents mentioned (builder, surfactant,
disintegration aid, bleaching agent and bleach activator), the detergent
tablets according to the invention may contain other typical detergent
ingredients from the group of dyes, perfumes, optical brighteners,
enzymes, foam inhibitors, silicone oils, redeposition inhibitors,
discoloration
inhibitors, dye transfer inhibitors and corrosion inhibitors.
Enzymes suitable for use in the basic tablets are, in particular, those
from the classes of hydrolases, such as proteases, esterases, lipases or
lipolytic enzymes, amylases, cellulases, glycosyl hydrolases and mixtures
thereof. All these hydrolases contribute to the removal of stains, such as
protein-containing, fat-containing or starch-containing stains.
Oxidoreductases may also be used for bleaching and for inhibiting dye
transfer. Enzymes obtained from bacterial strains or fungi, such as Bacillus
CA 02313875 2000-07-14
subtilis, Bacillus licheniformis, Streptomyces griseus, Coprinus cinereus
and Humicola insolens and from genetically modified variants are
particularly suitable. Proteases of the subtilisin type are preferably used,
proteases obtained from Bacillus lentus being particularly preferred. Of
5 particular interest in this regard are enzyme mixtures, for example of
protease and amylase or protease and lipase or lipolytic enzymes or of
protease, amylase and lipase or lipolytic enzymes or protease, lipase or
lipolytic enzymes and cellulase, but especially protease- andlor lipase-
containing mixtures or mixtures with lipolytic enzymes. Examples of such
10 lipolytic enzymes are the known cutinases. Peroxidases or oxidases have
also been successfully used in some cases. Suitable amylases include in
particular a-amylases, isoamylases, pullanases and pectinases.
The enzymes may be adsorbed to supports andlor encapsulated in
membrane materials to protect them against premature decomposition.
15 The percentage content of the enzymes, enzyme mixtures or enzyme
granules may be, for example, from about 0.1 to 5% by weight and is
preferably from 0.5 to about 4.5% by weight. Preferred detergent tablets
according to the invention are characterized in that the basic tablet
contains protease and/or amylase.
20 By virtue of the fact that the detergent tablets according to the
invention may contain the enzymes) in two basically different regions (in
the basic tablet andlor as active substance or active substance mixture in
the cavity), it is possible to provide detergents characterized by a very
precisely defined enzyme release and effect. The following Table provides
25 an overview of possible enzyme distributions in detergent tablets according
to the invention:
CA 02313875 2000-07-14
66
Basic tablet Cavity
Amylase -, -
Protease -
Lipase
Amylase + Protease -
Amylase + Lipase
Protease + Lipase -
Amylase + Protease + Lipase-
- Amylase
- Protease
- Lipase
- Amylase + Protease
- Amylase + Lipase
- Protease + Lipase
- Amylase + Protease + Lipase
Amylase Amylase
Protease Amylase
Amylase + Protease Amylase
Amylase Protease
Protease Protease
Amylase + Protease Protease
Amylase Amylase + Protease
Protease Amylase + Protease
Amylase + Protease Amylase + Protease
Lipase Amylase
Amylase + Lipase Amylase
Protease + Lipase Amylase
Amylase + Protease + LipaseAmylase
Lipase Protease
Amylase + Lipase Protease
Protease + Lipase Protease
Amylase + Protease + LipaseProtease
-
Lipase Amylase + Protease
Amylase + Lipase Amylase + Protease
Protease + Lipase Amylase + Protease
Amylase + Protease + LipaseAmylase + Protease
Dyes and perfumes may be added to the detergent tablets according
to the invention both in the basic tablet and in the preparations present in
the cavity in order to improve the aesthetic impression created by the
CA 02313875 2000-07-14
67
products and to provide the consumer not only with the required
performance but also with a visually and sensorially "typical and
unmistakable" product. Suitable perfume oils or perfumes include
individual perfume compounds, for example synthetic products of the ester,
ether, aldehyde, ketone, alcohol and hydrocarbon type. Perfume com-
pounds of the ester type are, for example, benzyl acetate, phenoxyethyl
isobutyrate, p-tert.butyl cyclohexyl acetate, linalyl acetate, dimethyl benzyl
carbinyl acetate, phenyl ethyl acetate, linalyl benzoate, benzyl formate,
ethyl methyl phenyl glycinate, allyl cyclohexyl propionate, styrallyl
propionate and benzyl salicylate. The ethers include, for example, benzyl
ethyl ether; the aldehydes include, for example, the linear alkanals
containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetal-
dehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal; the
ketones include, for example, the ionones, a-isomethyl ionone and methyl
cedryl ketone; the alcohols include anethol, citronellol, eugenol, geraniol,
linalool, phenyl ethyl alcohol and terpineol and the hydrocarbons include,
above all, the terpenes, such as limonene and pinene. However, mixtures
of various perfumes which together produce an attractive perfume note are
preferably used. Perfume oils such as these may also contain natural
perfume mixtures obtainable from vegetable sources, for example pine,
citrus, jasmine, patchouli, rose or ylang-ylang oil. Also suitable are clary
oil, camomile oil, clove oil, melissa oil, mint oil, cinnamon leaf oil, lime
blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil and
labdanum oil and orange blossom oil, neroli oil, orange peel oil and
sandalwood oil.
The perfumes may be directly incorporated in the detergents
according to the invention, although it can also be of advantage to apply
the perfumes to supports which strengthen the adherence of the pertume
to the washing and which provide the textiles with a long-lasting fragrance
through a slower release of the perfume. Suitable support materials are,
CA 02313875 2000-07-14
68
for example, cyclodextrins, the cyclodextrinlperfume complexes optionally
being coated with other auxiliaries.
In order to improve their aesthetic impression, the detergents
according to the invention (or parts thereof) may be colored with suitable
dyes. Preferred dyes, which are not difficult for the expert to choose, have
high stability in storage, are not affected by the other ingredients of the
detergents or by light and do not have any pronounced substantivity for the
substrates to be treated with the detergents, such as textiles, glass,
ceramics or plastic tableware, so as not to color them.
The detergent tablets according to the invention may contain one or
more optical brightener(s). These substances, which are also known as
"whiteners", are used in modern detergents because even freshly washed
and bleached white laundry has a slight yellowish tinge. Optical
brighteners are organic dyes which convert part of the invisible UV
radiation in sunlight into longer wave blue light. The emission of this blue
light fills the "gap" in the light reflected by the fabric, so that a fabric
treated
with optical brightener appears whiter and brighter to the eye. Since the
action mechanism of brighteners presupposes their absorption onto the
fibers, brighteners are differentiated according to the fibers "to be
colored",
for example as brighteners for cotton, polyamide or polyester fibers. The
commercially available brighteners suitable for incorporation in detergents
largely belong to eve structural groups, namely: the stilbene, the Biphenyl
stilbene, the coumarinlquinoline and the Biphenyl pyrazoline group and the
group where benzoxazole or benzimidazole is combined with conjugated
systems. Conventional brighteners are reviewed, for example, in G.
Jakobi, A. Lohr "Detergents and Textile Washing", VCH-Verlag,
Weinheim, 1987, pages 94 to 100. Suitable brighteners are, for example,
salts of 4,4'-bis-[(4-anilino-6-morpholino-s-triazin-2-yl)-amino]-stilbene-
2,2'-
disulfonic acid or compounds of similar structure which, instead of the
morpholino group, contain a diethanolamino group, a methylamino group,
_ CA 02313875 2000-07-14
69
an anilino group or a 2-methoxyethylamino group. Brighteners of the
substituted diphenyl styryl type, for example alkali metal salts of 4,4'-bis-
(2-
sulfostyryl)-diphenyl, 4,4'-bis-(4-chloro-3-sulfostyryl)-diphenyl or 4-(4-
chlorostyryl)-4'-(2-sulfostyryl)-diphenyl, may also be present. Mixtures of
the brighteners mentioned above may also be used.
In addition, the detergent tablets according to the invention may also
contain components with a positive effect on the removal of oil and fats
from textiles by washing (so-called soil repellents). This effect becomes
particularly clear when a textile which has already been repeatedly washed
with a detergent according to the invention containing this oil- and fat-
dissolving component is soiled. Preferred oil- and fat-dissolving compo-
nents include, for example, nonionic cellulose ethers, such as methyl
cellulose and methyl hydroxypropyl cellulose containing 15 to 30% by
weight of methoxyl groups and 1 to 15% by weight of hydroxypropoxyl
groups, based on the nonionic cellulose ether, and the polymers of phthalic
acid andlor terephthalic acid known from the prior art or derivatives thereof,
more particularly polymers of ethylene terephthalates andlor polyethylene
glycol terephthalates or anionically andlor nonionically modified derivatives
thereof. Of these, the sulfonated derivatives of phthalic acid and
terephthalic acid polymers are particularly preferred.
Foam inhibitors suitable for use in the detergents according to the
invention are, for example, soaps, paraffins and silicone oils which may
optionally be applied to carrier materials.
The function of redeposition inhibitors is to keep the soil detached
from the fibers suspended in the wash liquor and thus to prevent the soil
from being re-absorbed by the washing. Suitable redeposition inhibitors
are water-soluble, generally organic colloids, for example the water-soluble
salts of polymeric carboxylic acids, glue, gelatine, salts of ether carboxylic
acids or ether sulfonic acids of starch or cellulose or salts of acidic
sulfuric
acid esters of cellulose or starch. Water-soluble polyamides containing
CA 02313875 2000-07-14
acidic groups are also suitable for this purpose. Soluble starch
preparations and other starch products than those mentioned above, for
example degraded starch, aldehyde starches, etc., may also be used.
Polyvinyl pyrrolidone is also suitable. However, cellulose ethers, such as
5 carboxymethyl cellulose (sodium salt), methyl cellulose, hydroxyalkyl
cellulose, and mixed ethers, such as methyl hydroxyethyl cellulose, methyl
hydroxypropyl cellulose, methyl carboxymethyl cellulose and mixtures
thereof are preferably used, for example in quantities of 0.1 to 5% by
weight, based on the detergent.
10 Since sheet-form textiles, more particularly of rayon, rayon staple,
cotton and blends thereof, can tend to crease because the individual fibers
are sensitive to sagging, kinking, pressing and squeezing transversely of
the fiber direction, the compositions according to the invention may contain
synthetic anticrease agents, including for example synthetic products
15 based on fatty acids, fatty acid esters, fatty acid amides, alkylol esters,
alkylol amides or fatty alcohols, which are generally reacted with ethylene
oxide, or products based on lecithin or modified phosphoric acid esters.
To control microorganisms, the compositions according to the
invention may contain antimicrobial agents. According to the antimicrobial
20 spectrum and the action mechanism, antimicrobial agents may be divided
into bacteriostatic agents and bactericides, fungistatic agents and
fungicides, etc. Important representatives of these groups are, for
example, benzalkonium chlorides, alkylaryl sulfates, halophenols and
phenol mercury acetate, although these compounds may also be absent
25 altogether.
In order to prevent unwanted changes in the compositions andlor
the fabrics treated with them attributable to the effects of oxygen and other
oxidative processes, the compositions may contain antioxidants. This class
of compounds includes, for example, substituted phenols, hydroquinones,
30 pyrocatechols and aromatic amines and also organic sulfides, polysulfides,
CA 02313875 2000-07-14
71
dithiocarbamates, phosphites and phosphonates.
Wearing comfort can be increased by the additional use of antistatic
agents which are additionally incorporated in the detergents according to
the invention. Antistatic agents increase surface conductivity and thus
provide for the improved dissipation of any charges which have built up.
External antistatic agents are generally substances containing at least one
hydrophilic molecule ligand and form a more or less hygroscopic film on the
surfaces. These generally interfacially active antistatic agents may be
divided into nitrogen-containing antistatics (amines, amides, quaternary
ammonium compounds), phosphorus-containing antistatics (phosphoric
acid esters) and sulfur-containing antistatics (alkyl sulfonates, alkyl
sulfates). External antistatic agents are described, for example, in patent
applications FR 1,156,513, GB 873,214 and GB 839,407. The lauryl (or
stearyl) dimethyl benzyl ammonium chlorides disclosed therein are suitable
as antistatic agents for textiles and as detergent additives and additionally
develop a conditioning effect.
In order to improve the water absorption capacity and rewettability of
the treated textiles and to make them easier to iron, silicone derivatives,
for
example, may be used in the compositions according to the invention.
Silicone derivatives additionally improve the rinsing out behavior of the
compositions through their foam-inhibiting properties. Preferred silicone
derivatives are, for example, polydialkyl and alkylaryl siloxanes where the
alkyl groups contain 1 to 5 carbon atoms and are completely or partly
fluorinated. Preferred silicones are polydimethyl siloxanes which may
optionally be derivatized and, in that case, are aminofunctional or
quaternized or contain Si-OH-, Si-H- and/or Si-CI bonds. The preferred
silicones have viscosities at 25°C of 100 to 100,000 centistokes and
may
be used in quantities of 0.2 to 5% by weight, based on the detergent as a
whole.
Finally, the compositions according to the invention mar also contain
CA 02313875 2000-07-14
72
UV filters which are absorbed onto the treated textiles and which improve
- the light stability of the fibers. Compounds which have these desirable
properties are, for example, the compounds acting by "radiationless"
deactivation and derivatives of benzophenone with substituents in the 2
position and/or 4 position. Substituted benzotriazoles, 3-phenyl-substituted
acrylates (cinnamic acid derivatives), optionally with cyano groups in the 2-
position, salicylates, organic Ni complexes and natural substances, such as
umbelliferone and the body's own urocanic acid.
The ingredients described above may of course also be incorporated
in the cavity filling. Preferred laundry/dishwasher detergent tablets
according to the invention are characterized in that the active substance
contained in the space defined by the film and the tablet contains at least
one active substance from the group of enzymes, surfactants, soil-release
polymers, disintegration aids, bleaching agents, bleach activators, bleach
catalysts, silver corrosion inhibitors and mixtures thereof.
Through the division of the laundryldishwasher detergent tablets
according to the invention into basic tablets and active substances) or
active substance mixtures or preparations) present in the cavity,
ingredients can be separated from one another which may be used either
to separate incompatible ingredients to improve their stability in storage or
for the controlled release of certain active substances. In preferred
laundryldishwasher detergent tablets, the basic tablet or the active
substance present in the space defined by the film and the tablet contains
bleaching agents while the other region of the tablet contains bleach
activators.
Other preferred laundryldishwasher detergent tablets according to
the invention are characterized in that the basic tablet or the active
substance present in the space defined by the film and the tablet contains
bleaching agents while the other region of the tablet contains enzymes.
Bleaching agent and corrosion inhibitors or silver corrosion inhibitors
. CA 02313875 2000-07-14
73
can also be separated. Laundryldishwasher detergent tablets in which the
basic tablet or the active substance present in the space defined by the film
and the tablet contains bleaching agents while the other region of the tablet
contains corrosion inhibitors are also preferred.
Last but not least, laundryldishwasher tablets in which the basic
tablet or the active substance contained in the space defined by the film
and the tablet contains bleaching agents while the other region of the tablet
contains surfactants, preferably nonionic surfactants and more preferably
alkoxylated alcohols containing 10 to 24 carbon atoms and 1 to 5 alkylene
oxide units, are also preferred.
With all the ingredients mentioned above, advantageous properties
can result from their separation from other ingredients or from their being
made up together with certain other ingredients. In the tablets according to
the invention, the individual regions may also have different contents of the
same ingredient, which can afford advantages. Preferred detergent tablets
are characterized in that the basic tablet and the active substance present
in the space defined by the film and the tablet contain the same active
substance in different quantities. The expression "different quantities" does
not relate to the absolute quantity of the ingredient in the particular part
of
the tablet, but rather to the relative quantity, based on the weight of the
phase, i.e. represents a percentage by weight, based on the individual
region, i.e. the basic tablet or the cavity filling.
The active substance optionally incorporated in the cavity is
preferably particulate. The expression "active substance" in the context of
the present invention is not confined to pure substances, but instead
characterizes pure active substances, active-substance mixtures and
preparations so that there are no limits to the freedom of formulation. If
particulate substances are incorporated in the cavities, they preferably
satisfy certain particle size criteria so that preferred detergent tablets are
characterized in that the active substance present in the space defined by
CA 02313875 2000-07-14
74
the film and the tablet has particle sizes of 100 to 5000 Nm, preferably in
the range from 150 to 2500 Nm, more preferably in the range from 200 to
2000 Nm and most preferably in the range from 400 to 1600 Nm.
Particularly preferred particulate compositions incorporated in the
cavity(ies) of the tablets according to the invention are those which contain
surfactants, these surfactants preferably being dissolution-retarded for
dishwasher detergents so that the surfactants are only released from the
cavity filling in the clear-rinse cycle. The rinse aid particles described in
earlier German patent application DE 199 14 364.1 (Henkel KGaA) have
proved to be particularly useful for this purpose. These particles which are
preferably to be introduced into the cavity consist of 0 to 90% by weight of
one or more carrier materials, 5 to 50% by weight of one or more
membrane materials with a melting point above 30°C, 5 to 50% by weight
of one or more active substances and 0 to 10% by weight of other active
substances and auxiliaries so that preferred detergent tablets are charac-
terized in that the active substance present in the space defined by the film
and the tablet comprises particles consisting of
a) 0 to 90% by weight of one or more carrier materials,
b) 5 to 50% by weight of one or more membrane materials with a melting
point above 30°C,
c) 5 to 50% by weight of one or more active substances and
0 to 10% by weight of other active substances and auxiliaries.
Reference is expressly made to the disclosure of that document.
Nevertheless, the most important ingredients of these "rinse aid particles"
preferably introduced into the cavity are described in the following.
Suitable carrier materials a) are any substances solid at room temperature.
Substances which develop an additional cleaning effect in the wash cycle,
particularly builders, will normally be used. The carrier materials present in
preferred particulate rinse aids for filling the cavity are substances from
the
group of water-soluble detergent ingredients, preferably carbonates,
CA 02313875 2000-07-14
hydrogen carbonates, sulfates, phosphates and oligocarboxylic acids solid
at room temperature used in quantities of 55 to 85% by weight, preferably
in quantities of 60 to 80% by weight and more preferably in quantities of 65
to 75% by weight, based on the weight of the particles.
5 The preferred carrier materials mentioned are described in detail
hereinafter.
The coating materials used in the active-substance particles
preferably used to fill the cavity in accordance with the invention are
expected to satisfy various requirements which relate on the one hand to
10 the melting or solidification behavior and, on the other hand, to the
material
properties of the coating in the solidified state, i.e in the active-substance
particle. Since the active-substance particles are intended to be
permanently protected against outside influences during transportation and
storage, the coating material must show high stability to the impacts
15 occurring, for example, during packaging or transportation. Accordingly,
the coating should have either at least partly elastic or at least plastic
properties in order to react to impact without breaking by elastic or plastic
deformation. The coating material should have a melting range (solidifi-
cation range) at temperatures at which the active substances to be coated
20 are not exposed to significant thermal stressing. On the other hand,
however, the melting range must be high enough still to afford the
encapsulated particles effective protection at at least slightly elevated
temperatures. According to the invention, the coating materials have a
melting point above 30°C.
25 It has been found to be of advantage if the coating material does not
have a sharply defined melting point, as would normally be the case with
pure crystalline substances, but rather a melting range possibly covering
several degrees Celsius.
The coating material preferably has a melting range of about 45°C to
30 about 75°C. This means in the present case that the melting range
lies
CA 02313875 2000-07-14
76
within the temperature range mentioned and does not denote the width of
the melting range. The width of the melting range is preferably at least 1
°C
and more preferably about 2 to about 3°C.
The properties mentioned above are generally exhibited by so-called
waxes. "Waxes" in the context of the present invention are understood to
be any of a number of natural or synthetic substances which generally melt
above 40°C without decomposing and, even just above their melting
point,
are of relatively low viscosity and non-stringing. Their consistency and
solubility are dependent to a large extent on temperature.
Waxes are divided into three groups according to their origin,
namely: natural waxes, chemically modified waxes and synthetic waxes.
The natural waxes include, for example, vegetable waxes, such as
candelilla wax, carnauba wax, Japan wax, esparto grass wax, cork wax,
guaruma wax, rice oil wax, sugar cane wax, ouricury wax or montan wax,
animal waxes, such as bees wax, shellac wax, spermaceti, lanolin (wool
wax) or uropygial fat, mineral waxes, such as ceresine or ozocerite (earth
wax), or petrochemical waxes, such as petrolatum, paraffin waxes or
microwaxes.
The chemically modified waxes include, for example, hard waxes,
such as montan ester waxes, sassol waxes or hydrogenated jojoba waxes.
Synthetic waxes are generally understood to be polyalkylene waxes
or polyalkylene glycol waxes. Compounds from other classes which satisfy
the above-mentioned softening point requirements may also be used as
coating materials. For example, higher esters of phthalic acid, more
particularly the dicyclohexyl phthalate commercially available under the
name of Unimoll~ 66 (Bayer AG), have proved to be suitable synthetic
compounds. Synthetic waxes of lower carboxylic acids and fatty alcohols,
for example the dimyristyl tartrate commercially available under the name
of Cosmacol~ ETLP (Condea), are also suitable. Conversely, synthetic or
partly synthetic esters of lower alcohols with fatty acids from native sources
CA 02313875 2000-07-14
77
may also be used. This class of substances includes, for example, Tegin~
90 (Goldschmidt), a glycerol monostearate palmitate. Shellac, for example
Schellack-KPS-Dreiring-SP (Kalkhoff GmbH), may also be used as a
coating material in accordance with the invention.
In the context of the invention, the waxes also include, for example,
the so-called wax alcohols. Wax alcohols are relatively high molecular
weight water-insoluble fatty alcohols generally containing about 22 to 40
carbon atoms. The wax alcohols are used as a principal constituent of
many natural waxes, for example in the form of wax esters of relatively high
molecular weight fatty acids (wax acids). Examples of wax alcohols are
lignoceryl alcohol (1-tetracosanol), cetyl alcohol, myristyl alcohol or
melissyl
alcohol. The coating of the solid particles coated in accordance with the
invention may also contain wool wax alcohols which are understood to be
triterpenoid and steroid alcohols, for example the lanolin obtainable, for
example, under the name of Argowax~ (Pamentier & Co.). According to
the invention, fatty acid glycerol esters or fatty acid alkanolamides and also
water-insoluble or substantially water-insoluble polyalkylene glycol
compounds may also be used at least partly as a constituent of the coating.
Particularly preferred coating materials in the active-substance
particles to be pressed into the cavity are those belonging to the group of
polyethylene glycols (PEGs) andlor polypropylene glycols (PPGs),
polyethylene glycols with molecular weights of 1,500 to 36,000 being
preferred, those with molecular weights of 2,000 to 6,000 being particularly
preferred and those with molecular weights of 3,000 to 5,000 being most
partiularly preferred.
Particularly preferred active-substance particles contain propylene
glycols (PPGs) and/or polyethylene glycols (PEGs) as sole coating
material. Polypropylene glycols (PPGs) suitable for use in accordance with
the invention are polymers of propylene glycol which correspond to general
formula XII:
- CA 02313875 2000-07-14
78
H-(O- iH-CH2)~-OH (XII)
CH3
where n may assume values of 10 to 2000. Preferred PPGs have
molecular weights of 1,000 to 10,000, corresponding to values of n of 17 to
about 170.
Polyethylene glycols (PEGs) preferably used in accordance with the
invention are polymers of ethylene glycol which correspond to general
formula XIII:
H-(O-CH2-CH2)n-OH (XI I I )
in which n may assume a value of 20 to about 1,000. The preferred
molecular weight ranges mentioned above correspond to preferred ranges
for the value of n in formula IV of ca. 30 to ca. 820 (more precisely: 34 to
818), preferably ca. 40 to ca. 150 (more precisely: 45 to 136) and more
preferably ca. 70 to ca. 120 (more precisely: 68 to 113)
In one preferred embodiment, the coating material present in the
active-substance particles according to the invention predominantly
contains paraffin wax. In other words, at least 50% by weight of the total of
coating materials present and preferably more consists of paraffin wax.
Paraffin wax contents (based on total coating material) of about 60% by
weight, about 70% by weight or about 80% by weight are particularly
suitable, even higher contents of, for example, more than 90% by weight
being particularly preferred. In one particular embodiment of the invention,
the total quantity of coating material used consists entirely of paraffin wax.
So far as the present invention is concerned, paraffin waxes have
the advantage over the other natural waxes mentioned that the waxes do
not undergo hydrolysis in an alkaline detergent environment (as might be
expected, for example, in the case of the wax esters), because a paraffin
. CA 02313875 2000-07-14
79
wax does not contain any hydrolyzable groups.
Paraffin waxes consist principally of alkanes and small amounts of
iso- and cycloalkanes. The paraffin to be used in accordance with the
invention preferably contains virtually no constituents with a melting point
above 70°C and, more preferably, above 60°C. If the temperature
in the
cleaning solution falls below this melting temperature, high-melting alkanes
in the paraffin can leave unwanted wax residues behind on the surfaces to
be cleaned or the ware to be cleaned. Wax residues such as these
generally leave the cleaned surface with an unattractive appearance and
should therefore be avoided.
Particulate rinse aids preferably introduced into the cavity contain at
least one paraffin wax with a melting range of 50°C to 60°C as
coating
material.
The paraffin wax used preferably has a high content of alkanes,
isoalkanes and cycloalkanes solid at ambient temperature (generally about
10 to about 30°C). The higher the percentage of solid wax constituents
present in a wax at room temperature, the more useful that wax is for the
purposes of the present invention. The higher the percentage of solid wax
constituents, the greater the resistance of the coating to impact or friction
with other surfaces, which leads to longer lasting protection of the coated
solid particles. Large percentages of oils or liquid wax constituents can
weaken the paticles so that pores are opened and the active substances
are thus exposed to the outside influences mentioned.
Besides paraffin as principal constituent, the coating material may
also contain one or more of the waxes or wax-like substances mentioned
above. Basically, the composition of the mixture forming the coating
material should be such that the rinse aid particles are at least
substantially
insoluble in water. Their solubility in water should not exceed about 10
mgll at a temperature of about 30°C and should preferably be below 5
mgll.
At all events, the coating should have very low solubility in water,
~
CA 02313875 2000-07-14
even in water at elevated temperature, in order largely to avoid the coated
active substances being released independently of temperature.
The principle described above facilitates the delayed release of
ingredients at a certain time in the wash cycle of a dishwasher and may be
5 applied with particular advantage when the main wash cycle is carried out
at a relatively low temperature (for example 55°C), so that the active
substance is only released from the active-substance particles in the final
rinse cycle at relatively high temperatures (ca. 70°C).
Preferred particulate rinse aids to be introduced into the cavity in
10 accordance to the invention are characterized in that they contain one or
more substances with a melting range of 40°C to 75°C as coating
material
in quantities of 6 to 30% by weight, preferably in quantities of 7.5 to 25% by
weight and more preferably in quantities of 10 to 20% by weight, based on
the weight of the particles. Detergent tablets in which the particles present
15 in the cavity contain paraffin(s) or polyalkylene glycols, more
particularly
polyethylene glycols, as coating material are particularly preferred.
The active substances present in the active-substance particles to
be introduced into the cavity in accordance with the invention may be
present both in solid and in liquid form at the processing temperature (i.e.
20 at the temperature at which the particles are produced).
The active substances present in the active-substance particles
perform certain functions. Cleaning performance can be improved through
the separation of certain substances or through the accelerated or delayed
release of additional substances. Accordingly, active substances
25 preferably incorporated in the active-substance particles are ingredients
of
detergents which are crucially involved in the washing or cleaning process.
Accordingly, in preferred active-substance particles to be introduced
into the cavity, one or more substances from the groups of surfactants,
enzymes, bleaching agents, bleach activators, corrosion inhibitors, scale
30 inhibitors, co-builders andlor perfumes are present as active substances in
~
CA 02313875 2000-07-14
81
quantities of 6 to 30% by weight, preferably 7.5 to 25% by weight and more
preferably 10 to 20% by weight, based on the weight of the particles.
Particularly preferred detergent tablets are characterized in that the active-
substance particles present in the space defined by the film and the tablet
contain nonionic surfactants) and/or bleaching agents andlor bleach
activator andlor enzymes) andlor corrosion inhibitors andlor perfumes as
active substances.
By incorporating surfactants in molten coating material, it is possible
to prepare a melt suspension or emulsion which provides additional
detersive substance at a predetermined time in the final active-substance
particles or in the final tablet according to the invention. For example, it
is
possible in this way to produce active-substance particles - suitable for
introduction into the cavity(ies) - for dishwashers which only release the
additional surfactant from the tablet according to the invention at
temperatures which domestic dishwashers only reach in the final rinse
cycle. In this way, additional detergent is available in the final rinse cycle
to
accelerate drainage of the water and thus effectively to prevent stains on
the tableware. Thus, with a suitable quantity of solidified melt suspension
or emulsion in the active-substance particles, there is no longer any need
to use the additional rinse aid typically encountered today.
Accordingly, in preferred active-substance particles to be introduced
into the cavity, the active substances) islare selected from the group of
nonionic surfactants, more particularly alkoxylated alcohols. These
substance have already been described in detail.
Another class of active substances which may be incorporated with
particular advantage in the active-substance particles suitable for
incorporation in accordance with the invention are bleaching agents. In
their case, particles can be produced and introduced into the cavities which
only release the bleaching agent on reaching certain temperatures, for
example fully compounded detergents which clean enzymatically in the
- CA 02313875 2000-07-14
82
prerinse cycle and only release the bleaching agent in the main wash cycle.
Dishwasher detergents can also be produced in such a way that additional
bleaching agents are released in the final rinse cycle so that difficult
stains,
for example tea stains, are more effectively removed.
Accordingly, in preferred active-substance particles to be introduced
into the cavity, the active substances) is/are selected from the group of
oxygen or halogen bleaching agents, more particularly chlorine bleaching
agents. These substances are also described in detail hereinafter.
Another class of compounds which may preferably be used as active
substances in the active-substance particles to be introduced in
accordance with the invention are bleach activators. The important
representatives of this group were also described in the foregoing. Active-
substance particles preferably pressed into the cavity in accordance with
the invention contain bleach activators, more particularly from the groups of
polyacylated alkylenediamines, more particularly tetraacetyl ethylenedi-
amine (TAED), N-acyl imides, more particularly N-nonanoyl succinimide
(NOSI), acylated phenol sulfonates, more particularly n-nonanoyl or iso-
nonanoyl-oxybenzenesulfonate (n- or iso-NOBS), n-methyl morpholinium
acetonitrile methyl sulfate (MMA), as active substance.
In another important embodiment of the present invention, enzyme-
containing particles are incorporated in the cavity(ies). Active-substance
particles such as these contain the enzymes described in detail in the
foregoing as active substance(s). Particularly preferred particles to be
introduced into the cavity(ies) are those which contain 40 to 99.5% by
weight, preferably 50 to 97.5% by weight, more preferably 60 to 95% by
weight and most preferably 70 to 90% by weight of one or more membrane
materials) with a melting point above 30°C, 0.5 to 60% by weight,
preferably 1 to 40% by weight, more preferably 2.5 to 30% by weight and
most preferably 5 to 25% by weight of one or more liquid enzyme
preparations) dispersed in the membrane materials) and 0 to 20% by
~
CA 02313875 2000-07-14
83
weight, preferably 0 to 15% by weight, more preferably 0 to 10% by weight
and most preferably 0 to 5% by weight of, optionally, other carrier
materials, auxiliaries andlor active substances. Accordingly, preferred
laundryldishwasher detergent tablets are characterized in that the active
substance present in the space defined by the film and the tablet
comprises particles which consist of
a) 40 to 99.5% by weight, preferably 50 to 97.5% by weight, more
preferably 60 to 95% by weight and most preferably 70 to 90% by
weight of one or more membrane materials) with a melting point above
30°C,
b) 0.5 to 60% by weight, preferably 1 to 40% by weight, more preferably
2.5 to 30% by weight and most preferably 5 to 25% by weight of one or
more liquid enzyme preparations) dispersed in the membrane
materials) and
c) 0 to 20% by weight, preferably 0 to 15% by weight, more preferably 0
to 10% by weight and most preferably 0 to 5% by weight of other
carrier materials, auxiliaries andlor active substances.
The membrane materials are preferably polyethylene glycols and/or
polypropylene glycols, liquid enzyme preparations having proved to be
effective active substances. Liquid enzyme concentrates are based either
homogeneously on propylene glycollwater or heterogeneously on a slurry
or are present in microencapsulated form. Preferred liquid proteases are,
for example, Savinase~ L, Durazym~ L, Esperase~ L and Everlase~
(Novo Nordisk), Optimase~ L, PurafectO L, Purafect~ OXL, ProperaseO L
(Genencor International) and BLAPO L (Biozym GmbH). Preferred
amylases are Termamyl~ L, Duramyl~ L and BAN~ (Novo Nordisk),
Maxamyl~ WL and Purafect~ HPAm L (Genencor International). Preferred
lipases are Lipolase~ L, Lipolase~ ultra L and Lipoprime~ L (Novo
Nordisk) and Lipomax~ L (Genencor International).
Such products as, for example, the Novo Nordisk products SL and
' CA 02313875 2000-07-14
84
LCC may be used as slurries or microencapsulated liquid products. The
commercially available liquid enzyme preparations mentioned contain, for
example, 20 to 90% by weight of propylene glycol or mixtures of propylene
glycol and water. Enzyme particles preferably incorporated in the cavity in
accordance with the invention are characterized in that they contain one or
more liquid amylase preparations andlor one or more liquid protease
preparations.
Perfumes may also be incorporated as active substances in the
particles to be introduced. All the perfumes described in detail in the
foregoing may be used as active substance. Where perfumes are
incorporated in the particles to be introduced, detergents which release all
or part of the perfume with delay are obtained. According to the invention,
it is possible in this way for example to produce dishwasher detergents
where the consumer experiences the perfume note even after the machine
has been opened on completion of the program. In this way, the unwanted
"alkali smell" characteristic of many dishwasher detergents can be
eliminated.
Corrosion inhibitors may also be introduced as active substance into
the particles, any of the corrosion inhibitors familiar to the expert being
suitable. A combination of enzyme (for example lipase) and lime soap
dispersant, for example, has been successfully used as a scale inhibitor.
At extremely low temperatures, for example at temperatures below
0°C, the rinse aid particles can disintegrate under impact or friction.
In
order to improve stability at temperatures as low as these, additives may
optionally be incorporated in the coating materials. Suitable additives must
be completely miscible with the molten wax, should not significantly alter
the melting range of the coating materials, should improve the elasticity of
the coating at low temperatures, should generally not increase the
permeability of the coating to water or moisture and should not increase the
viscosity of the molten coating material to such an extent as to make
- CA 02313875 2000-07-14
processing difficult or even impossible. Suitable additives which reduce the
brittleness of a coating consisting essentially of paraffin at low
temperatures are, for example, EVA copolymers, hydrogenated resin acid
methyl esters, polyethylene or copolymers of ethyl acrylate and 2
5 ethylhexyl acrylate.
Another useful additive where paraffin is used as the coating is a
surfactant, for example a C~2_~8 fatty alcohol sulfate, used in a small
quantity. This additive improves the wetting of the material to be
encapsulated by the coating. In one advantageous embodiment, it is
10 added in a quantity of about < 5% by weight and preferably < about 2% by
weight based on the coating material. In many cases, the effect of adding
an additive can be to promote the coating of even those active substances
which, without the additive, would generally form a viscous plastic mass of
paraffin and partly dissolved active substance after melting of the coating
15 material.
It can also be of advantage to incorporate other additives in the
coating material, for example to prevent premature sedimentation of the
active substances. This is particularly advisable in the production of the
active-substance particles according to the invention without carrier
20 materials. Suitable antisedimenting agents, which are also known as
antisettling agents, are known from the prior art, for example from the
production of paints and printing inks. Sedimentation phenomena and
concentration gradients of the substances to be coated during the transition
from the plastic solidification range to the solid can be counteracted, for
25 example, by interfacially active substances, waxes dispersed in solvents,
montmorillonites, organically modified bentonites, (hydrogenated) castor oil
derivatives, soya lecithin, ethyl cellulose, low molecular weight polyamides,
metal stearates, calcium soaps or hydrophobicized silicas. Other sub-
stances which have the effects mentioned belong inter alia to the groups of
30 antifloating agents and thixotropicizing agents and, chemically, may be
CA 02313875 2000-07-14
86
classed as silicone oils (dimethyl polysiloxanes, methylphenyl
polysiloxanes, polyether-modified methylalkyl polysiloxanes), oligomeric
titanates and silanes, polyamines, salts of long-chain polyamines and
polycarboxylic acids, aminelamide-functional polyesters and aminelamide
functional polyacrylates.
Additives from the classes mentioned above are commercially
available in large numbers. Commercial products which may advantage-
ously be used as additives in the process according to the invention are, for
example, Aerosil~ 200 (pyrogenic silica, Degussa), Bentone4 SD-1, SD-2,
34, 52 and 57 (bentonite, Rheox), Bentone~ SD-3, 27 and 38 (hectorite,
Rheox), Tixogel~ EZ 100 or VP-A (organically modified smectite,
Sudchemie), Tixogel~ VG, VP and VZ (QUAT-charged montmorillonite,
Sudchemie), Disperbyk~ 161 (block copolymer, Byk-Chemie), Borchigen~
ND (sulfo-group-free ion exchanger, Borchers), Ser-Ad~ FA 601 (Servo),
Solsperse~ (aromatic ethoxylate, ICI), Surfynol~ types (Air Products),
Tamol~ and Triton~ types (Rohm & Haas), Texaphor~ 963, 3241 and
3250 (polymers, Henkel), Rilanit~ types (Henkel), Thixcin~ E and R (castor
oil derivatives, Rheox), Thixatrol~ ST and GST (castor oil derivatives,
Rheox). Thixatrol~ SR, SR 100, TSR and TSR 100 (polyamide polymers,
Rheox), Thixatrol0 289 (polyester polymer, Rheox) and the various M-P-
A~ types X, 60-X, 1078-X, 2000-X and 60-MS (organic compounds
Rheox).
The additives mentioned may be used in varying quantities in the
rinse aid or enzyme particles to be introduced in accordance with the
invention, depending on the coating material and the active substance.
The antisettling agents, antifloating agents and thixotropicizing agents and
dispersants mentioned above are typically used in concentrations of 0.5 to
8.0% by weight, preferably in concentrations of 1.0 to 5.0% by weight and
more preferably in concentrations of 1.5 to 3.0% by weight, based on the
total quantity of coating material and active substances.
' CA 02313875 2000-07-14
87
Rinse aid or enzyme particles preferably introduced into the
cavity(ies) in accordance with the inventio contain further auxiliaries from
the group of antisedimenting agents, antisettling agents, antifloating
agents, thixotropicizing agents and dispersion aids in quantities of 0.5 to
9% by weight, preferably in quantities of 1 to 7.5% by weight and more
preferably in quantities of 1.5 to 5% by weight, based on the weight of the
particles.
Particularly in the production of melt suspensions or emulsions
containing additives which are liquid at the processing temperature, it is of
advantage to use special emulsifiers. It has been found that, above all,
emulsifiers from the group of fatty alcohols, fatty acids, polyglycerol esters
and polyoxyalkylene siloxanes are particularly suitable.
In the context of the invention, fatty alcohols are understood to be
the C6_22 alcohols obtainable from native fats or oils via the corresponding
fatty acids (see below). Depending on the origin of the fat or oil from which
they are obtained, these alcohols may be substituted or locally unsaturated
in the alkyl chain. Accordingly, C6_22 fatty alcohols, preferably C$_22 fatty
alcohols, more preferably C,2_~8 fatty alcohols and most preferably C~6_,a
fatty alcohols are used as emulsifiers in the active-substance particles
according to the invention.
Other suitable emulsifiers are any fatty acids obtained from
vegetable or animal oils and fats. Irrespective of their aggregate state, the
fatty acids may be saturated or mono- to polyunsaturated. With the
unsaturated fatty acids also, the species solid at room temperature are
preferred to the liquid or paste-form species. It is of course possible to use
not only "pure" fatty acids, but also the technical fatty acid mixtures
obtained in the hydrolysis of fats and oils, these mixtures being distinctly
preferred from the economic point of view.
For example, individual species or mixtures of the following acids
may be used as emulsifiers in accordance with the present invention:
CA 02313875 2000-07-14
88
caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid,
palmitic
acid, stearic acid, octadecan-12-oleic acid, arachic acid, behenic acid,
lignoceric acid, cerotic acid, melissic acid, 10-undecenoic acid, petroselic
acid, petroselaidic acid, oleic acid, elaidic acid, ricinoleic acid,
linolaidic
acid, a- and [3-elaeostearic acid, gadoleic acid, erucic acid, brassidic acid.
It is of course also possible to use the fatty acids with an odd number of
carbon atoms, for example undecanoic acid, tridecanoic acid, pentadeca-
noic acid, heptadecanoic acid, nonadecanoic acid, heneicosanoic acid,
tricosanoic acid, pentacosanoic acid, heptacosanoic acid.
C6_22 fatty acids, preferably C8_22 fatty acids, more preferably C~2_~s
fatty acids and most preferably C~6_~8 fatty acids are used as emulsifiers) in
preferred rinse aid or enzyme particles prefeerably introduced into the
cavity.
According to the invention, particularly preferred emulsifiers are
polyglycerol esters, more particularly esters of fatty acids with poly-
glycerols. These preferred polyglycerol esters may be represented by
general formula XIV:
R'
HO-[CH2-CH-CH2-O]~-H (XIV)
in which the substituents R' in each glycerol unit independently of one
another represent hydrogen or a fatty acyl group containing 8 to 22 and
preferably 12 to 18 carbon atoms and n is a number of 2 to 15 and
preferably 3 to 10.
These polyglycerol esters are known and commercially available,
more especially with degrees of polymerization n of 2, 3, 4, 6 and 10.
Since substances of the type mentioned are also widely used in cosmetic
formulations, some of them are also classified in the INCI nomenclature
(CTFA International Cosmetic Ingredient Dictionary and Handbook, Stn
CA 02313875 2000-07-14
89
Edition, The Cosmetic, Toiletry and Fragrance Association, Washington,
1997). For example, this cosmetic dictionarylhandbook contains
information on the keywords POLYGLYCERYL-3-BEESWAX, POLYGLY-
CERYL-3-CETYL ETHER, POLYGLYCERYL-4-COCOATE, POLYGLY-
CERYL-10-DECALINOLEATE, POLYGLYCERYL-10-DECAOLEATE,
POLYGLYCERYL-10-DECASTEARATE, POLYGLYCERYL-2-DIISO-
STEARATE, POLYGLYCERYL-3-DIISOSTEARATE, POLYGLYCERYL-10-
DISOSTEARATE, POLYGLYCERYL-2-DIOLEATE, POLYGLYCERYL-3-
DIOLEATE, POLYGLYCERYL-6-DIOLEATE, POLYGLYCERYL-10-DIOLE-
ATE, POLYGLYCERYL-3-DISTEARATE, POLYGLYCERYL-6-DISTEAR-
ATE, POLYGLYCERYL-10-DISTEARATE, POLYGLYCERYL-10-HEPTA-
OLEATE, POLYGLYCERYL-12-HYDROXYSTEARATE, POLYGLYCERYL-
10-HEPTASTEARATE, POLYGLYCERYL-6-HEXAOLEATE, POLYGLY-
CERYL-2-ISOSTEARATE, POLYGLYCERYL-4-ISOSTEARATE, POLY-
GLYCERYL-6-ISOSTEARATE, POLYGLYCERYL-10-LAURATE, POLY-
GLYCERYLMETHACRYLATE, POLYGLYCERYL-10-MYRISTATE, POLY-
GLYCERYL-2-OLEATE, POLYGLYCERYL-3-OLEATE, POLYGLYCERYL-
4-OLEATE, POLYGLYCERYL-6-OLEATE, POLYGLYCERYL-8-OLEATE,
POLYGLYCERYL-10-OLEATE, POLYGLYCERYL-6-PENTAOLEATE,
POLYGLYCERYL-10-PENTAOLEATE, POLYGLYCERYL-6-PENTA-
STEARATE, POLYGLYCERYL-10-PENTASTEARATE, POLYGLYCERYL-
2-SESQUIISOSTEARATE, POLYGLYCERYL-2-SESQUIOLEATE,
POLYGLYCERYL-2-STEARATE, POLYGLYCERYL-3-STEARATE, POLY-
GLYCERYL-4-STEARATE, POLYGLYCERYL-8-STEARATE, POLYGLY-
CERYL-10-STEARATE, POLYGLYCERYL-2-TETRAISOSTEARATE,
POLYGLYCERYL-10-TETRAOLEATE, POLYGLYCERYL-2-TETRA-
STEARATE, POLYGLYCERYL-2-TRIISOSTEARATE, POLYGLYCERYL-
10-TRIOLEATE, POLYGLYCERYL-6-TRISTEARATE. The commercially
obtainable products of various manufacturers which are classified under
the above-mentioned keywords in the dictionarylhandbook mentioned
CA 02313875 2000-07-14
above may advantageously be used as emulsifiers in process step b)
according to the invention.
Another group of emulsifiers which may be used in the rinse aid or
enzyme particles to be introduced into the cavity(ies) in accordance with
5 the invention are substituted silicones which carry side chains reacted with
ethylene or propylene oxide. These polyalkylene siloxanes may be
represented by general formula XV:
R~ R' R~
H3C- i i-O-[ i i-O]"- i i-CH3 (XV)
R' R' R~
in which the substituents R' independently of one another represent -CH3
or a polyoxyethylene or polyoxypropylene group -[CH(RZ)-CH2-O]XH group,
R2 represents -H or -CH3, x is a number of 1 to 100, preferably 2 to 20 and
more particularly below 10 and n is the degree of polymerization of the
silicone.
The polyoxyalkylene siloxanes mentioned may also be etherified or
esterified at the free OH groups of the polyoxyethylene or polyoxypropylene
side chains. The unetherified and unesterified polymer of dimethyl siloxane
with polyoxyethylene andlor polyoxypropylene is known under the INCI
nomenclature as DIMETHICONE COPOLYOL and is commercially
available under the names of Abil~ B (Goldschmidt), Alkasil~ (Rhone-
Poulenc), Silwet~ (Union Carbide) or Belsil~ DMC 6031.
The DIMETHICONE COPOLYOL ACETATE esterified with acetic
acid (for example Belsil~ DMC 6032, 6033 and 6035, Wacker) and the
DIMETHICONE COPOLYOL BUTYL ETHER (for example KF352A, Sin
Etsu) may also be used as emulsifiers in accordance with the invention.
In the same way as the coating materials and the substances to be
coated, the emulsifiers may be used over a widely varying range.
CA 02313875 2000-07-14
91
Emulsifiers of the type mentioned normally make up 1 to 25% by weight,
preferably 2 to 20% by weight and more preferably 5 to 10% by weight of
the sum of coating materials and active substances. Particulate rinse aids
or enzymes preferably introduced into the cavity(ies) in accordance with the
invention additionally contain emulsifiers from the group of fatty alcohols,
fatty acids, polyglycerol esters andlor polyoxyalkylene siloxanes in
quantities of 0.1 to 5% by weight, preferably in quantities of 0.2 to 3.5% by
weight, more preferably in quantities of 0.5 to 2% by weight and most
preferably in quantities of 0.75 to 1.25% by weight, based on the weight of
the particles.
The laundryldishwasher detergent tablets according to the invention
dissolve completely in the washing or cleaning cycle. As mentioned above,
it can be of advantage if the various regions dissolve at different rates. By
virtue of the different dissolving rates, not only can certain ingredients be
released at certain times, the properties of the wash liquor can also be
selectively varied. For example, preferred laundryldishwasher detergent
tablets are characterized in that the pH of a 1 % by weight solution of the
basic tablet in water is in the range from 8 to 12, preferably in the range
from 9 to 11 and more preferably in the range from 9.5 to 10.
Other preferred laundry/dishwasher detergent tablets are charac-
terized in that the pH of a 1 % by weight solution of the tablet as a whole in
water is in the range from 7 to 11, preferably in the range from 7.5 to 10
and more preferably in the range from 8 to 9.5.
The present invention also relates to a process for the production of
laundryldishwasher detergent tablets which comprises the steps of
a) compressing a particulate premix to form a compressed portion (basic
tablet) which has at least one cavity,
b) optionally introducing one or more active substances into the
cavity(ies) in liquid, gel, paste or solid form,
c) optionally applying one or more adhesion promoters to one or more
' CA 02313875 2000-07-14
92
surfaces of the tablet,
d) closing the openings of the (filled) cavities with a film and
e) optionally aftertreating individual tablet surfaces or the tablet as a
whole.
The foregoing observations on the tablets according to the invention
apply equally to the ingredients of the individual regions of the tablets
according to the invention or rather their particulate premixes or
compositions which make up the various regions of the tablet.
It has proved to be of advantage if the premix compressed to form
basic tablets in step a) satisfies certain physical criteria. Preferred
processes are characterized, for example, in that the particulate premix in
step a) has a bulk density of at least 500 gll, preferably of at least 600 gll
and more preferably of at least 700 gll.
The particle size of the premix tabletted in step a) also preferably
satisfies certain criteria. According to the invention, preferred processes
are characterized in that the particulate premix in step a) has particle sizes
of 100 to 2000 Nm, preferably in the range from 200 to 1800 Nm, more
preferably in the range from 400 to 1600 Nm and most preferably in the
range from 600 to 1400 Nm. A narrower particle size range in the
premixes to be tabletted may be adjusted in order to acquire advantageous
tablet properties. In preferred variants of the process according to the
invention, the particulate premix tabletted in step a) has a particle size
distribution where less than 10% by weight, preferably less than 7.5% by
weight and more preferably less than 5% by weight of the particles are
larger than 1600 Nm or smaller than 200 Nm. Narrower particle size
distributions are even more preferred. Particularly advantageous variants
of the process are characterized in that the particulate premix tabletted in
step a) has a particle size distribution where more than 30% by weight,
preferably more than 40% by weight and more preferably more than 50%
by weight of the particles have a particle size of 600 to 1000 Nm.
' CA 02313875 2000-07-14
93
Step a) of the process according to the invention is not confined to
compressing just one particulate premix to form a tablet. Instead, process
step a) may also be augmented to the extent that multilayer tablets are
produced in known manner by preparing two or more premixes which are
pressed onto one another. In this case, the first premix introduced is lightly
precompressed in order to obtain a smooth upper surface running parallel
to the base of the tablet and, after the second premix has been introduced,
the whole is compressed to form the final tablet. In the case of tablets with
three or more layers, each addition of premix is followed by further
precompression before the tablet is compressed for the last time after
addition of the last premix. The above-described cavity in the basic tablet
is preferably a recess so that preferred embodiments of the first process
according to the invention are characterized in that multilayer tablets
comprising a recess are produced in known manner in step a) by pressing
several different particulate premixes onto one another.
The tablets according to the invention are produced in step a) by first
dry-mixing the ingredients - which may be completely or partly
pregranulated - and then shapinglforming, more particularly tabletting, the
resulting mixture using conventional processes. To produce the tablets
according to the invention, the premix is compacted between two punches
in a die to form a solid compactate. This process, which is referred to in
short hereinafter as tabletting, comprises four phases, namely metering,
compacting (elastic deformation), plastic deformation and ejection.
The premix is first introduced into the die, the filling level and hence
the weight and shape of the tablet formed being determined by the position
of the lower punch and the shape of the die. Uniform dosing, even at high
tablet throughputs, is preferably achieved by volumetric dosing of the
premix. As the tabletting process continues, the top punch comes into
contact with the premix and continues descending towards the bottom
punch. During this compaction phase, the particles of the premix are
- CA 02313875 2000-07-14
94
pressed closer together, the void volume in the filling between the punches
continuously diminishing. The plastic deformation phase in which the
particles coalesce and form the tablet begins from a certain position of the
top punch (and hence from a certain pressure on the premix). Depending
on the physical properties of the premix, its constituent particles are also
partly crushed, the premix sintering at even higher pressures. As the
tabletting rate increases, i.e. at high throughputs, the elastic deformation
phase becomes increasingly shorter so that the tablets formed can have
more or less large voids. In the final step of the tabletting process, the
tablet is forced from the die by the bottom punch and carried away by
following conveyors. At this stage, only the weight of the tablet is
definitively established because the tablets can still change shape and size
as a result of physical processes (re-elongation, crystallographic effects,
cooling, etc.).
The tabletting process is carried out in commercially available tablet
presses which, in principle, may be equipped with single or double
punches. In the latter case, not only is the top punch used to build up
pressure, the bottom punch also moves towards the top punch during the
tabletting process while the top punch presses downwards. For small
production volumes, it is preferred to use eccentric tablet presses in which
the punches) islare fixed to an eccentric disc which, in turn, is mounted on
a shaft rotating at a certain speed. The movement of these punches is
comparable with the operation of a conventional four-stroke engine.
Tabletting can be carried out with a top punch and a bottom punch,
although several punches can also be fixed to a single eccentric disc, in
which case the number of die bores is correspondingly increased. The
throughputs of eccentric presses vary according to type from a few hundred
to at most 3,000 tablets per hour.
For larger throughputs, rotary tablet presses are generally used. In
rotary tablet presses, a relatively large number of dies is arranged in a
CA 02313875 2000-07-14
circle on a so-called die table. The number of dies varies - according to
model - between 6 and 55, although even larger dies are commercially
available. Top and bottom punches are associated with each die on the
die table, the tabletting pressures again being actively built up not only by
5 the top punch or bottom punch, but also by both punches. The die table
and the punches move about a common vertical axis, the punches being
brought into the filling, compaction, plastic deformation and ejection
positions by means of curved guide rails. At those places where the
punches have to be raised or lowered to a particularly significant extent
10 (filling, compaction, ejection), these curved guide rails are supported by
additional push-down members, pull-down rails and ejection paths. The die
is filled from a rigidly arranged feed unit, the so-called filling shoe, which
is
connected to a storage container for the premix. The pressure applied to
the premix can be individually adjusted through the tools for the top and
15 bottom punches, pressure being built up by the rolling of the punch shank
heads past adjustable pressure rollers.
To increase throughput, rotary presses can also be equipped with
two filling shoes so that only half a circle has to be negotiated to produce a
tablet. To produce two-layer or multiple-layer tablets, several filling shoes
20 are arranged one behind the other without the lightly compacted first layer
being ejected before further filling. Given suitable process control, shell
and bull's-eye tablets - which have a structure resembling an onion skin -
can also be produced in this way. In the case of bull's-eye tablets, the
upper surface of the core or rather the core layers is not covered and thus
25 remains visible. Rotary tablet presses can also be equipped with single or
multiple punches so that, for example, an outer circle with 50 bores and an
inner circle with 35 bores can be simultaneously used for tabletting.
Modern rotary tablet presses have throughputs of more than one million
tablets per hour.
30 Where rotary presses are used for tabletting, it has proved to be of
CA 02313875 2000-07-14
96
advantage to carry out the tabletting process with minimal variations in the
weight of the tablets. Variations in tablet hardness can also be reduced in
this way. Minimal variations in weight can be achieved as follows:
- using plastic inserts with minimal thickness tolerances
- low rotor speed
- large filling shoe
- adapting the rotational speed of the filling shoe blade to the rotor speed
- filling shoe with constant powder height
- decoupling the filling shoe from the powder supply
Any of the nonstick coatings known in the art may be used to reduce
caking on the punch. Plastic coatings, plastic inserts or plastic punches are
particularly advantageous. Rotating punches have also proved to be of
advantage; if possible, the upper and lower punches should be designed
for rotation. If rotating punches are used, there will generally be no need
for a plastic insert. In that case, the surfaces of the punch should be
electropolished.
It has also been found that long tabletting times are advantageous.
These can be achieved by using pressure rails, several pressure rollers or
low rotor speeds. Since variations in tablet hardness are caused by
variations in the pressures applied, systems which limit the tabletting
pressure should be used. Elastic punches, pneumatic compensators or
spring elements in the force path may be used. The pressure roller can
also be spring-mounted.
Preferred processes according to the invention are characterized in
that tabletting in step a) is carried out under pressures of 0.01 to 50
kNcrri 2, preferably 0.1 to 40 kNcm 2 and more preferably 1 to 25 kNcm 2.
Tabletting machines suitable for the purposes of the invention can
be obtained, for example, from the following companies: Apparatebau
Holzwarth GbR, Asperg; Wilhelm Fette GmbH, Schwarzenbek; Hofer
GmbH, Weil; Horn & Noack Pharmatechnik GmbH, Worms; IMA
- CA 02313875 2000-07-14
. 97
Verpackungssysteme GmbH Viersen; KILIAN, Cologne; KOMAGE, Kell am
See, KORSCH Pressen GmbH, Berlin; and Romaco GmbH, Worms. Other
suppliers are, for example Dr. Herbert Pete, Vienna (AU); Mapag
Maschinenbau AG, Bern (Switzerland); BWI Manesty, Liverpool (GB); I.
Holand Ltd., Nottingham (GB); and Courtoy N.V., Halle (BEILU) and
Medicopharm, Kamnik (SI). One example of a particularly suitable
tabletting machine is the model HPF 630 hydraulic double-pressure press
manufactured by LAEIS, D. Tabletting tools are obtainable, for example,
from Adams Tablettierwerkzeuge Dresden; Wilhelm Fett GmbH,
Schwarzenbek; Klaus Hammer, Solingen; Herber & Sohne GmbH,
Hamburg; Hofer GmbH, Weil; Horn & Noack, Pharmatechnik GmbH,
Worms; Ritter Pharmatechnik GmbH, Hamburg; Romaco GmbH, Worms
and Notter Werkzeugbau, Tamm. Other suppliers are, for example, Senss
AG, Reinach (CH) and Medicopharm, Kamnik (SI).
In step b), the cavity is optionally filled with active substance(s),
active-substance mixtures or active-substance preparations. If the cavity
has more than one opening, it is advisable for process-related reasons to
close the second, third and any other openings in order in this way to
simplify the filling process. Although it would also be possible in principle
first to fill a ring tablet and then to close the upper opening of the hole,
to
turn over the tablet together with its filling and to close the second hole
also, this would require mechanisms to prevent the filling from dropping
out. If, therefore, the cavity of the tablet produced in step a) has more than
one opening, the optional step b) - filling - is preferably carried out after
steps c) and d) have been carried out (n-1 ) times where n is the number of
openings. Accordingly, closing of the last opening corresponds to the last
time process steps c) and d) are carried out to be followed by process step
e).
As mentioned above, the filling optionally introduced into the cavity
is preferably solid, particulate fillings being particularly preferred. If the
- CA 02313875 2000-07-14
98
cavities of the tablets are filled with particulate compositions, processes in
which the particulate compositions in step b) haslhave a bulk density of at
least 500 gll, preferably of at least 600 gll and more preferably of at least
700 g/l are preferred.
In step c) of the process according to the invention, adhesion
promoters are optionally applied to one or more surfaces of the tablet.
Step c) is necessary in particular when the films to be applied in the
following step are not sufficiently adhesive on their own to remain on the
tablet and to withstand the mechanical stresses involved in packaging,
transportation and handling without releasing the filling. Accordingly,
process c) is intended to enable films which are not sufficiently adhesive on
their own to be "stuck on".
Suitable adhesion promoters are substances which provide the
tablet surfaces to which they are applied with sufficient adhesiveness
("tackiness") for the films applied in the following process step to adhere
permanently to the surface. In principle, the substances mentioned in the
relevant literature - above all monographs - on adhesives may be used as
adhesion promoters, particular significance being attributed in the context
of the present invention to the application of melts which have an adhesion-
promoting effect at elevated temperature, but which are no longer tacky,
but solid, after cooling.
Process step d), namely application of the film to some or all of the
surfaces of the tablet and the resulting closure of the cavity(ies), was
discussed in detail in the foregoing. Reference is made here to the
relevant observations in order to avoid unnecessary repetition:
As described above, the tablets produced in accordance with the
invention may be completely or partly provided with a coating. According to
the invention, processes in which the aftertreatment in step e) consists in
the application of a coating to the entire tablet are preferred.
The laundryldetergent tablets according to the invention may be
' CA 02313875 2000-07-14
_ 99
packed after their production, the use of certain packs having proved to be
particularly effective. Another aspect of the present invention is a
combination of (a) laundryldishwasher detergent tablets) and a pack
containing the tablet(s), characterized in that the pack has a water vapor
transmission rate of 0.1 glm2lday to less than 20 glm2lday when it is stored
at 23°CI85% relative equilibrium humidity.
According to the invention, the pack of the tablet(s)Ipack
combination has a water vapor transmission rate of 0.1 glm2lday to less
than 20 glm2/day when the pack is stored at 23°CI85% relative
equilibrium
humidity. The temperature and humidity conditions mentioned are the test
conditions specified in DIN 53122, according to which minimal deviations
are acceptable (23 ~ 1 °C, 85 ~ 2% relative humidity). The water vapor
transmission rate of a given pack or material can be determined by other
standard methods and is also described, for example, in ASTM Standard
E-96-53T ("Test for Measuring Water Vapor Transmission of Materials in
Sheet Form") and in TAPPI standard T464 m-45 ("Water Vapor
Permeability of Sheet Materials at High Temperatures and Humidity"). The
measurement principle of standard methods is based on the water
absorption of anhydrous calcium chloride which is stored in a container in
the corresponding atmosphere, the container being closed on top by the
material to be tested. The water vapor transmission rate can be calculated
from the surface of the container closed by the material to be tested
(permeation surface), the increase in weight of the calcium chloride and the
exposure time in accordance with the following equation:
24 ~ 10000 x
WVTR = ~- [ g I mz / 24h]
A y
where A is the surface area of the material to be tested in cm2, x is the
increase in weight of the calcium chloride in g and y is the exposure time in
h.
' CA 02313875 2000-07-14
_ 100
The relative equilibrium humidity, often referred to as "relative air
humidity", in the measurement of the water vapor transmission rate for the
purposes of the present invention is 85% at 23°C. The absorption
capacity
of air for water vapor increases with temperature to a particular maximum
content, the so-called saturation content, and is expressed in glm3. For
example, 1 m3 of air at 17° is saturated with 14.4 g of water vapor,
the
saturation content at 11 ° being as much as 10 g of water vapor. The
relative air humidity is the ratio expressed in percent between the water
vapor content actually present and the saturation content corresponding to
the prevailing temperature. If, for example, air at 17° contains 12
g/m3
water vapor, the relative air humidity is (12114.4)100 = 83%. If this air is
cooled, saturation (100% relative humidity) is reached at the so-called dew
point (in the example 14°), i.e. a deposit in the form of mist (dew) is
formed
with further cooling. Hygrometers and psychrometers are used for the
quantitative determination of humidity.
The relative equilibrium humidity of 85% at 23°C can be adjusted to
an accuracy of ~ 2% relative humidity (depending on the instrument used),
for example in humidity-controlled laboratory chambers. Oversaturated
solutions of certain salts also form constant and well-defined relative air
humidities at a given temperature in closed systems, these relative air
humidities being based on the phase equilibrium between the partial
pressure of the water, the saturated solution and the sediment.
The detergent tabletlpack combinations according to the invention
may of course themselves be packed in secondary packs, for example
cardboard boxes or trays, the secondary pack having to meet no other
requirements. Accordingly, the secondary pack is possible, not necessary.
Preferred packs according to the invention have a water vapor
transmission rate of 0.5 g/m2lday to less than 15 glm2lday.
The pack of the combination according to the invention surrounds
one or more laundryldishwasher detergent tablets, depending on the
' CA 02313875 2000-07-14
_ 101
embodiment of the invention. In one preferred embodiment of the
invention, a tablet may be made up in such a way that it constitutes a dose
or dosage unit of the laundryldishwasher detergent and may be individually
packed or tablets may be packed in a pack in numbers which, together,
constitute a dose or dosage unit. Accordingly, for a prescribed dose of 80
g of detergent, it is possible in accordance with the invention to produce
and individually pack a detergent tablet weighing 80 g. However, it is also
possible in accordance with the invention to pack two detergent tablets
each weighing 40 g in one pack in order to obtain a combination according
to the invention. This principle may of course also be extended so that,
according to the invention, combinations of three, four, five or even more
detergent tablets may be accommodated in one and the same pack. Two
or more tablets in the same pack may of course have different
compositions. In this way, certain components can be spatially separated
from one another in order, for example, to avoid stability problems.
The pack of the combination according to the invention may consist
of various materials and may assume various external forms. For
economic reasons and in the interests of easier processability, however,
preferred packs are those in which the packaging material is light in weight,
easy to process and inexpensive. In preferred combinations according to
the invention, the pack consists of a bag of single-layer or laminated paper
andlor plastic film.
The laundryldishwasher detergent tablets may be introduced without
sorting, i.e. loosely, into a bag of the materials mentioned above. However,
for aesthetic reasons and for sorting the combinations in secondary packs,
bags are filled either with single tablets or with several tablets in sorted
form. The term "flow pack" is now commonly used for individual dosage
units of the detergent tablets accommodated in a bag. Flow packs may
optionally be packed - again preferably sorted - in outer packs which
underscores the compact supply form of detergent tablets.
CA 02313875 2000-07-14
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The bags of single-layer or laminated paper or plastic film preferably
used as the pack may be designed in various ways, for example as inflated
bags with no center seam or as bags with a center seam which are closed
by heat (heat sealing), adhesives or adhesive tape. Single-layer bag
materials are the known papers, which may optionally be impregnated, and
plastic films which may optionally be co-extruded. Plastic films which may
be used as the pack of the combination according to the invention are
described, for example, in Hans Domininghaus "Die Kunststoffe and
ihre Eigenschaften" 3rd Edition, VDI Verlag, Diisseldorf, 1988, page
193. Figure 111 of this publication also provides reference points in
respect of the water vapor transmission of the materials mentioned.
Particularly preferred combinations according to the invention
contain a bag of single-layer or laminated plastic film with a thickness of 10
to 200 Nm, preferably 20 to 100 Nm and more preferably 25 to 50 pm as
the pack.
Although wax-coated papers in the form of paperboard articles may
also be used in addition to the films or papers mentioned as the pack for
the laundryldetergent tablets according to the invention, the pack
preferably does not comprise any wax-coated paper. The term "pack" in
the context of the present invention always characterizes the primary pack
of the tablets, i.e. the pack which is in direct contact with the surface of
the
tablets on its inside. An optional secondary pack does not have to meet
any requirements so that any of the usual materials and systems may be
used.
As mentioned earlier on, the laundry/dishwasher detergent tablets of
the combination according to the invention contain other ingredients of
detergents in varying quantities, depending on the application envisaged.
Irrespective of the application envisaged for the tablets, it is preferred in
accordance with the invention for the laundryldishwasher detergent tablets
to have a relative equilibrium moisture content of less than 30% at
35°C.
CA 02313875 2000-07-14
- 103
The relative equilibrium moisture content of the laundryldishwasher
detergent tablets may be determined by standard methods. The following
procedure was selected for the present investigations: a water-imperme-
able 1-liter vessel with a cover having a closable opening for the insertion
of samples was filled with a total of 300 g of detergent tablets and kept at a
constant temperature of 23°C for 24 hours in order to guarantee the
vessel
and the substance a uniform temperature. The water vapor pressure in the
space above the tablets can then be determined with a hygrometer
(Hygrotest 6100, Testoterm Ltd., England). The water vapor pressure is
measured every 10 minutes until two successive values show no deviation
(equilibrium moisture content). The hygrometer mentioned above enables
the values recorded to be directly displayed in % relative moisture.
Embodiments of the combination according to the invention in which
the pack is re-closable are also preferred. Combinations in which the pack
has a microperforation can also be produced with advantage in accordance
with the invention.
The present invention also relates to a process for washing textiles
in a domestic washing machine, characterized in that one or more laundry
detergent tablets according to the invention is/are placed in the dispensing
compartment of the washing machine and a washing program during which
the tablets) islare flushed into the wash liquor is carried out.
However, the tablets) doesldo not have to be dispensed from the
dispensing compartment, but may also be placed directly in the drum of the
washing machine. Although a dispensing aid, for example a net dispenser,
may be used for this purpose, the tablets may also be directly added to the
washing in the drum without a dispensing aid. Accordingly, the present
invention also relates to a process for washing textiles in a domestic
washing machine in which one or more laundry detergent tablets)
according to the invention islare placed in the drum of the washing
machine with or without a dispensing aid and a washing program during
CA 02313875 2000-07-14
104
which the tablets) is/are dissolved is carried out.
As mentioned earlier on, dishwasher detergent tablets may also be
produced by the process according to the invention. Accordingly, the
present invention also relates to a process for cleaning tableware in a
dishwashing machine which is characterized in that one or more
dishwasher detergent tablets) according to the invention is/are placed in
the dispensing compartment of the dishwasher and a dishwashing program
during which the dispensing compartment opens and the tablets) is/are
dissolved is carried out.
In the dishwashing process according to the invention, too, there is
no need to place the tablets) in the dispensing compartment, instead
it/they may be placed, for example, in the cutlery basket. However, a
dispensing aid, for example in the form of a basket-like container placed in
the interior of the dishwasher may also readily be used. Accordingly, the
present invention also relates to a process for cleaning tableware in a
dishwasher in which one or more dishwasher tablets) according to the
invention is placed in the interior of the dishwasher with or without a
dispensing aid and a dishwashing program during which the tablets) islare
dissolved is carried out.
Examples
Production of dishwasher tablets
Process ste~a,~ production of cavity tablets
Two-layer rectangular tablets with a cavity in the form of a semi
ellipse were produced by compressing two different premixes. 75% of the
tablets consisted of lower phase and 25% by weight of upper phase. The
composition (in % by weight, based on the particular premix) of the two
premixes and hence of the two different phases of the cavity tablets is
shown in the following Table:
CA 02313875 2000-07-14
_ 105
Premix 1 Premix 2
(lower phase)(upper phase)
Sodium carbonate 32.0 -
Sodium tripolyphosphate 52.0 91.4
Sodium perborate 10.0 -
Tetraacetyl ethylenediamine2.5 -
Benzotriazole 1.0 -
C~2 fatty alcohol ~ 3E0 2.5 -
Dye 0.2
Enzymes 6.0
Perfume 0.4
Silicone oil 2.0
The weight of the basic tablet was 20 g.
Process ste~y: filling with active substance
The cavity was filled with commercially available particulate enzyme
preparations (protease BLAP~ S 260, Biozym GmbH) with a bulk density
of 800 gll and a mean particle size of 400 Nm as a particulate active
substance. The quantity of filling was 1 g, the cavity volume being 80%
filled.
Process ste~c): ap~ying adhesion ~moters to the ss rf~ ace
The cavity tablets filled in step b) were coated on their upper surface
where the cavity was situated with 100 mg of a 20% solution of polyvinyl
alcohol (Mowiol~ 10-98, Hoechst).
Process ste,l~l: application of the film
The filled cavity tablets coated with adhesion promoter around the
' CA 02313875 2000-07-14
106
edges of the cavity were closed with a polyvinyl alcohol film (Greensol type
M8630).
Process ste~e)~: aftertreatment
The tablets according to the invention were dried for 4 minutes at
40°C.
The tablets according to the invention were distinguished by a firm
bond between the film and the basic tablet so that there was no loss of
active substance. If a tablet is introduced into water (20°C,
16°dH), the
polyvinyl alcohol film is seen to expand and, immediately afterwards, burst
open to release the enzyme particles. The contents of the cavity filling are
completely released in 5 seconds.
The invention may be varied in any number of ways as would be
apparent to a person skilled in the art and all obvious equivalents and the
like are meant to fall within the scope of this description and claims. The
description is meant to serve as a guide to interpret the claims and not to
limit them unnecessarily.
