Note: Descriptions are shown in the official language in which they were submitted.
CA 02316591 2000-08-23
1
LAUNDRY DETERGENT OR CLEANING PRODUCT TABLETS
Field of the Invention
The present invention relates to tablets having
detergent and cleaning properties and to processes for
producing them. The invention relates in particular to
laundry detergent and cleaning product tablets used for
laundering textiles in a domestic washing machine,
referred to for short as laundry detergent tablets.
Background of the Invention
Laundry detergent and cleaning product tablets have
been widely described in the prior art and are enjoying
increasing popularity among users owing to the ease of
dosing. Tableted ~ laundry detergents and cleaning
products have a number of advantages over their powder-
form counterparts: they are easier to dose and to
handle, and have storage and transport advantages owing
to their compact structure. Consequently, there exists
an extensive patent literature describing laundry
detergent and cleaning product tablets. One problem
which occurs again and again in connection with the use
of wash-active and detersive tablets is the
insufficient disintegration and dissolution rate of the
tablets under service conditions. Since sufficiently
stable tablets, i.e., dimensionally stable and
fracture-resistant tablets, can be produced only by
means of relatively high compressive pressures, there
is severe compaction of the tablet constituents and,
consequently, retarded disintegration of the tablet in
the aqueous liquor, and thus excessively slow release
of the active substances in the washing or cleaning
operation. The retarded disintegration of the tablets
has the further disadvantage that customary laundry
detergent and cleaning product tablets cannot be rinsed
CA 02316591 2000-08-23
2
in via the dispenser drawer of domestic washing
machines, since the tablets do not break down with
sufficient rapidity into secondary particles which are
small enough to be rinsed out of the dispenser drawer
into the washing drum.
Multifarious approaches for solving this problem exist
in the prior art. In addition to the use of specific
ingredients intended to promote disintegration, the
coating of individual ingredients, and the sieving of
the premixes for compression, are proposed.
For instance, EP-A-0 466 484 (Unilever) discloses
laundry detergent tablets wherein the premix for
compression has particle sizes of between 200 and
1200 ~.m, the upper and lower particle size limits
differing by not more than 700 Vim. The compression of
markedly coarser particles to tablets is not suggested
in this document.
EP-A-0 522 766 (Unilever) relates to tablets of a
compacted particulate laundry detergent composition
comprising surfactants, builders and disintegration
aids (based, for example, on cellulose), at least some
of the particles being coated with the disintegrant,
which when the tablets are dissolved in water exhibits
both a binder activity and a disintegration activity.
This document also refers to the general difficulty of
producing tablets combining adequate stability with
effective solubility. In this case the particle size in
the mixture for compression is to be above 200 Vim, with
the upper and lower limits on the individual particle
sizes differing from one another by not more than
700 Vim. In this document as well it is explicitly
CA 02316591 2000-08-23
3
stated that the particles should be no coarser than
1200 Vim.
Among the proposed solutions for achieving better
disintegration times, preference is to be given to
those which very largely refrain from the additional
use of substances which are not ingredients of laundry
detergents or cleaning products. In order to develop
highly compact formulations without "ballast", there
continues to be a need for proposed solutions based on
the selection and/or compounding of substances which
also develop advantageous activities in the course of
washing or cleaning.
Summary of the Invention
It is an object of the present invention to provide
laundry detergent and cleaning product tablets which
feature high hardness and have outstanding
disintegration properties. It should be possible to
dose these laundry detergent and cleaning product
tablets by way, inter alia, of the dispenser drawer,
without the user thereby experiencing disadvantages
owing to residues in the dispenser drawer and too
little detergent in the wash liquor. In addition to
these tablet-specific properties, the washing and
cleaning performance of the tablets of the invention
should also be excellent. The advantageous properties
of the tablets should be achieved not by additives
which merely serve to improve the tablet properties but
instead by the targeted use of substances which also
develop an activity in the washing and cleaning
process.
It has now been found that the use of specific
cobuilders in defined amounts enhances the profile of
CA 02316591 2000-08-23
4
properties of laundry detergent or cleaning product
tablets.
The invention provides laundry detergent or cleaning
product tablets comprising compacted particulate
laundry detergent or cleaning product, said tablets
comprising oxidized derivatives of starch and/or
dextrins in amounts of from 0.1 to 10% by weight, based
on the tablet weight.
Oxidized derivatives of starch are also referred to as
"oxidized starches"; oxidized derivatives of dextrins
are oxidized starch degradation products.
Representatives from both classes of substance are
often referred to collectively by the term "oxidized
starch".
Starch is a homoglycan - more precisely, a glucan. In
contradistinction to the situation in cellulose,
however, the glucose units in the starch polysaccharide
are linked a-glycosidically. Furthermore, starch is
composed of two components of different molecular mass:
approximately 20-30% by weight straight-chain amylose
(molecular mass approximately 50,000-150,000) and
70-80% by weight branched-chain amylopectin (molecular
mass approximately 300,000-2,000,000), together with
small amounts of lipids, phosphoric acid, and cations.
Whereas the amylose, owing to the 1,4-linkage, forms
long, helical, interlooped chains comprising
approximately 300-1200 glucose molecules, in the case
of amylopectin the chain branches after an average of
25 glucose units by 1,6-linkage to form a treelike
structure comprising approximately 1500-12,000
molecules of glucose.
. CA 02316591 2000-08-23
By treatment with different oxidizing agents, starches
can be converted with particle degradation into
carbonyl- and carboxy-containing derivatives, known as
oxidized starches. The most important oxidizing agent
5 industrially is sodium hypochlorite, which in an
alkaline medium acts on starch suspended in water. The
thinly viscous dispersions which result may be dried to
give free-flowing powder products.
Dextrins are starch degradation products with the
general formula (C6HloOs) wxHzO, which consist of glucose
chains and are formed on incomplete hydrolysis of
dilute acids (acid dextrins) or by the action of heat
(torrefaction dextrins). Enzymatic degradation with
amylases produces the so-called boundary dextrins, in
which there is accumulation of the amylopectin 1,6-
glycosidic linkages, which are not amenable to the
attack of (3-amylase, whereas the action of Bacillus
macerans on starch solution produces cyclodextrins.
Dextrins form colorless or yellow, amorphous powders
which are very readily soluble in water but almost
totally insoluble in alcohol. In the USA, dextrins are
prepared from corn, in the Federal Republic of Germany
predominantly from potatoes. The corn dextrins are
odorless, while the dextrin obtained from potato starch
has a cucumberlike smell. The dextrins of very high
molecular mass give (like starch) a blue coloration
with iodine solution, the next degradation stage is
colored red or brown with iodine, and the low molecular
mass dextrins no longer give any iodine coloration.
Depending on preparation process, the dextrins have a
molecular mass of between 2000 and 500,000. These are
preferably hydrolysis products which have average
molecular masses in the range from 400 to
CA 02316591 2000-08-23
6
300,000 g/mol. Preference is given to a polysaccharide
having a dextrose equivalent (DE) in the range from 0.5
to 40, in particular from 2 to 30, DE being a common
measure of the reducing activity of a polysaccharide in
comparison to dextrose, which possesses a DE of 100. It
is possible to use both maltodextrins having a DE of
between 3 and 20 and dry glucose syrups having a DE of
between 20 and 37, and also so-called yellow dextrins
and white dextrins having higher molecular masses, in
the range from 2000 to 30,000 g/mol.
The oxidized derivatives of dextrins comprise their
products of reaction with oxidizing agents which are
able to oxidize at least one alcohol function of the
saccharide ring to the carboxylic function. A preferred
dextrin is described in European Patent Application
EP 0 703 292. Oxidized dextrins obtainable from these
dextrins, and processes for preparing them, are known,
for example, from European Patent Applications
EP 427 349, EP 472 042 and EP 542 496 and from
International Patent Applications WO 93/08251,
WO 93/16110, WO 95/07303 and WO 95/12619. Preference is
given to a product oxidized at C6 of the saccharide
ring, as obtainable in accordance with the process of
one of International Patent Applications WO 93/16110,
WO 94/28030, WO 95/20608 and WO 96/03439. Also
preferred, however, is the use of dextrins modified at
their originally reductive end by oxidation, possibly
with loss of a carbon atom. If the originally reductive
end of the oligosaccharide was an anhydroglucose unit,
the unit present in this case following modification is
an arabinonic acid unit:
(glucose) n -~ (glucose) n_1 arabinonic acid.
CA 02316591 2000-08-23
7
In this case the average degree of oligomerization is
n, which as a variable requiring analytical
determination may also adopt fractional values,
preferably in the range from 2 to 20, in particular
from 2 to 10. This last-mentioned oxidative
modification may take place, for example, with the aid
of Fe, Cu, Ag, Co or Ni catalysts, as described in
International Patent Application WO 92/18542, with the
aid of Pd, Pt, Rh or Os catalysts, as described in
European Patent EP 0 232 202, or by means of a
quinone/hydroquinone system in alkaline medium with
addition of oxygen and with or without aftertreatment
with hydrogen peroxide.
Detailed Description of the Invention
Laundry detergent or cleaning product tablets of the
invention comprising oxidized derivatives of starch
and/or dextrins having average molecular masses in the
range from 440 to 500,000 in amounts of from 0.25 to
7.5% by weight, preferably from 0.5 to 5% by weight,
with particular preference from 0.75 to 3.5% by weight,
and in particular from 1 to 2% by weight, based on the
tablet weight, are just as preferred as laundry
detergent or cleaning product tablets wherein the
oxidized derivatives of starch and/or dextrins have
dextrose equivalents (DE) of from 0.1 to 50, preferably
from 0.5 to 40, and in particular from 2 to 30.
As already mentioned, particular preference is given to
laundry detergent or cleaning product tablets wherein
the oxidized derivatives of starch and/or dextrins are
products oxidized at C6 of the saccharide ring.
The oxidized derivatives of starch and/or dextrins may
be incorporated into the laundry detergent or cleaning
CA 02316591 2000-08-23
8
product tablets of the invention directly in the as-
supplied form or after prior compounding. For example,
the oxidized derivatives of starch and/or dextrins may
be added as particulate solids to the premix for
compression or may be sprayed in the form of an aqueous
solution onto the premix. Also possible is the
incorporation of the oxidized derivatives of starch
and/or dextrins into individual constituents of the
particulate premix, for example, into compounded
components such as builder compounds or into surfactant
granules.
A preferred mode of incorporation is to admix the
oxidized derivatives of starch and/or dextrins in
finely divided form to the premix for compression.
Preferred laundry detergent or cleaning product tablets
are therefore those comprising oxidized derivatives of
starch and/or dextrins in the form of compounded
components ("compounds") having an average particle
size of below 500 Vim, preferably below 450 Vim, and in
particular below 400 Vim.
These compounds may be obtained, for example, by spray-
drying commercial solutions of oxidized derivatives of
starch and/or dextrins, or by spraying such solutions
onto carrier materials such as sodium carbonate, sodium
sulfate or silicates, or zeolites. It is of course also
possible to use the commercial particulate oxidized
derivatives of starch and/or dextrins, in which case
said compounds consist entirely of oxidized derivatives
of starch and/or dextrins. The advantageousness results
in this case from the specified particle size range. In
the case where the oxidized derivatives of starch
and/or dextrins are added in the form of finely divided
compounds, it is preferred for the compounds to have
_ CA 02316591 2000-08-23
9
very high active substance contents. Accordingly,
preferred laundry detergent or cleaning product tablets
are those wherein the compounds comprise the oxidized
derivatives of starch and/or dextrins in amounts of
more than 10% by weight, preferably of more than 20% by
weight, and in particular of more than 30% by weight,
based in each case on the weight of the compound.
An alternative mode of incorporation for the oxidized
derivatives of starch and/or dextrins is to incorporate
them into individual constituents of the premix before
the premix is blended. Particularly suitable for this
purpose are surfactant granules, in whose preparation
aqueous solutions of oxidized derivatives of starch
and/or dextrins may be used as granulating aids . It is
of course possible to combine a plurality of modes of
incorporation for the oxidized derivatives of starch
and/or dextrins with one another and both to use
surfactant granules comprising them and to add the
oxidized derivatives of starch and/or dextrins in, for
example, finely divided form to the premix. It is
preferred, however, when using surfactant granules
comprising the oxidized derivatives of starch and/or
dextrins, for these granules to comprise the totality
of all oxidized derivatives of starch and/or dextrins
that are present in the tablets. Accordingly, laundry
detergent or cleaning product tablets comprising the
oxidized derivatives of starch and/or dextrins in the
form of surfactant granules which comprise the totality
of the oxidized derivatives of starch and/or dextrins
present in the tablets are preferred embodiments of the
present invention.
Surfactant granules, their ingredients, and processes
for preparing them are described later on below. As
_ CA 02316591 2000-08-23
regards the amount of oxidized derivatives of starch
and/or dextrins, preference is given to laundry
detergent or cleaning product tablets wherein the
amount of oxidized derivatives of starch and/or
5 dextrins in the surfactant granules is from 0.5 to 20%
by weight, preferably from 0.75 to 15% by weight, with
particular preference from 1 to 10% by weight, and in
particular from 1.5 to 5% by weight, based in each case
on the weight of the surfactant granules.
More generally, preference is given as well to laundry
detergent and cleaning product tablets comprising
compacted particulate laundry detergent or cleaning
product and comprising surfactant granules that
comprise oxidized derivatives of starch and/or
dextrins.
In addition to the oxidized derivatives of starch
and/or dextrins, the laundry detergent or cleaning
product tablets of the invention comprise further
ingredients of laundry detergents or cleaning products.
Among these, in particular, builders and surfactants
occupy a conspicuous position. The laundry detergent or
cleaning product tablets of the invention may comprise
all of the builders commonly used in laundry detergents
and cleaning products, i.e., in particular, zeolites,
silicates, carbonates, organic cobuilders, and - where
there are no ecological prejudices against their use -
phosphates as well.
Suitable crystalline, layered sodium silicates possess
the general formula NaMSiXO2X+lyH2~, where M is sodium or
hydrogen, x is a number from 1.9 to 4, y is a number
from 0 to 20, and preferred values for x are 2, 3 or 4.
Crystalline phyllosilicates of this kind are described,
CA 02316591 2000-08-23
11
for example, in European Patent Application EP-A-0 164
514. Preferred crystalline phyllosilicates of the
formula indicated are those in which M is sodium and x
adopts the value 2 or 3. In particular, both Vii- and
8-sodium disilicates NaZSizO5~yH20 are preferred,
(3-sodium disilicate, for example, being obtainable by
the process described in International Patent
Application WO-A-91/08171.
It is also possible to use amorphous sodium silicates
having an NazO:Si02 modulus of from 1:2 to 1:3.3,
preferably from 1:2 to 1:2.8, and in particular from
1:2 to 1:2.6,
which are
dissolution-retarded
and have
secondary washing properties. The retardation of
dissolution relative to conventional amorphous sodium
silicates
may have
been brought
about in
a variety
of
ways - for example, by surface treatment, compounding,
compacting, or overdrying. In the context of this
invention, the term "amorphous" also embraces "X-ray-
amorphous". This means that in X-ray diffraction
experiments the silicates do not yield the sharp X-ray
reflections typical of crystalline substances but
instead yield
at best
one or more
maxima of
the
scattered -radiation, having a width of several degree
X
units of
the diffraction
angle. However,
good builder
properties may result, even particularly good builder
properties, if the silicate particles in electron
diffraction experiments yield blurred or even sharp
diffraction maxima. The interpretation of this is that
the product s have microcrystalline regions with a size
of from 10 to several hundred nm, values up to max.
50 nm and in particular up to max. 20 nm being
preferred. So-called X-ray-amorphous silicates of this
kind, whic h likewise possess retarded dissolution
relative
to the conventional
waterglasses,
are
CA 02316591 2000-08-23
12
described, for example, in German Patent Application
DE-A-44 00 024. Particular preference is given to
compacted amorphous silicates, compounded amorphous
silicates, and overdried X-ray-amorphous silicates.
The finely crystalline, synthetic zeolite used,
containing bound water, is preferably zeolite A
and/or P. A particularly preferred zeolite P is Zeolite
MAP~ (commercial product from Crosfield). Also
suitable, however, are zeolite X and also mixtures of
A, X and/or P. A product available commercially and
able to be used with preference in the context of the
present invention, for example, is a cocrystallizate of
zeolite X and zeolite A (approximately 80% by weight
zeolite X), which is sold by CONDEA Augusta S.p.A.
under the brand name VEGOBOND AX~ and may be described
by the formula
nNa20~ (1-n) KzO~Al203~ (2-2 . 5) Si02~ (3 . 5-5.5) H20.
The zeolite may be used either as a builder in a
granular compound or as a kind of "powdering" for the
entire mixture intended for compression, it being
common to utilize both methods for incorporating the
zeolite into the premix. Suitable zeolites have an
average particle size of less than 10 ~m (volume
distribution; measurement method: Coulter counter) and
contain preferably from 18 to 22% by weight, in
particular from 20 to 22% by weight, of bound water.
Of course, the widely known phosphates may also be used
as builder substances provided such a use is not to be
avoided on ecological grounds. Among the large number
of commercially available phosphates, the alkali metal
phosphates, with particular preference being given to
_ CA 02316591 2000-08-23
13
pentasodium and pentapotassium triphosphate (sodium and
potassium tripolyphosphate, respectively), possess the
greatest importance in the laundry detergent and
cleaning product industry.
Alkali metal phosphates is the collective term for the
alkali metal (especially sodium and potassium) salts of
the various phosphoric acids, among which
metaphosphoric acids (HP03)n and orthophosphoric acid
H3P04, in addition to higher-molecular-mass
representatives, may be distinguished. The phosphates
combine a number of advantages: they act as alkali
carriers, prevent limescale deposits on machine
components, and lime incrustations on fabrics, and
additionally contribute to cleaning performance.
Sodium dihydrogen phosphate, NaHzP04, exists as the
dehydrate (density 1.91 g cm-3, melting point 60°) and
as the monohydrate (density 2.04 g cm-3). Both salts are
white powders of very ready solubility in water which
lose the water of crystallization on heating and
undergo conversion at 200°C into the weakly acidic
diphosphate (disodium dihydrogen diphosphate, Na2H2P20~)
and at the higher temperature into sodium
trimetaphosphate (Na3P309) and Maddrell's salt (see
below). NaH2P04 reacts acidically; it is formed if
phosphoric acid is adjusted to a pH of 4.5 using sodium
hydroxide solution and the slurry is sprayed. Potassium
dihydrogen phosphate (primary or monobasic potassium
phosphate, potassium biphosphate, PDP), KHZPOg, is a
white salt with a density of 2.33 g cm-3, has a melting
point of 253° [decomposition with formation of
potassium polyphosphate (KP03)X], and is readily soluble
in water.
CA 02316591 2000-08-23
14
Disodium hydrogen phosphate (secondary sodium
phosphate), Na2HP04, is a colorless, crystalline salt
which is very readily soluble in water. It exists in
anhydrous form and with 2 mol (density 2.066 g cm-3,
water loss at 95°), 7 mol (density 1.68 g cm-3, melting
point 48° with loss of 5 HZO), and 12 mol of water
(density 1.52 g cm-3, melting point 35° with loss of
5 H20), becomes anhydrous at 100°, and if heated more
severely undergoes transition to the diphosphate
Na4P20~. Disodium hydrogen phosphate is prepared by
neutralizing phosphoric acid with sodium carbonate
solution using phenolphthalein as indicator.
Dipotassium hydrogen phosphate (secondary or dibasic
potassium phosphate), KZHP04, is an amorphous white salt
which is readily soluble in water.
Trisodium phosphate, tertiary sodium phosphate, Na3P04,
exists as colorless crystals which as the dodecahydrate
have a density of 1.62 g cm-3 and a melting point of
73-76°C (decomposition), as the decahydrate
(corresponding to 19-20% P205) have a melting point of
100°C, and in anhydrous form (corresponding to 39-40%
P205) have a density of 2.536 g cm-3. Trisodium
phosphate is readily soluble in water, with an alkaline
reaction, and is prepared by evaporative concentration
of a solution of precisely 1 mol of disodium phosphate
and 1 mol of NaOH. Tripotassium phosphate (tertiary or
tribasic potassium phosphate), K3P04, is a white,
deliquescent, granular powder of density 2.56 g cm-3,
has a melting point of 1340°, and is readily soluble in
water with an alkaline reaction. It is produced, for
example, when Thomas slag is heated with charcoal and
potassium sulfate. Despite the relatively high price,
the more readily soluble and therefore highly active
potassium phosphates are frequently preferred in the
CA 02316591 2000-08-23
cleaning products industry over the corresponding
sodium compounds.
Tetrasodium diphosphate (sodium pyrophosphate), Na4P20-,,
5 exists in anhydrous form (density 2.534 g cm-3, melting
point 988°, 880° also reported) and as the decahydrate
(density 1.815-1.836 g cm-3, melting point 94° with loss
of water). Both substances are colorless crystals which
dissolve in water with an alkaline reaction. Na4P20~ is
10 formed when disodium phosphate is heated at > 200° or
by reacting phosphoric acid with sodium carbonate in
stoichiometric ratio and dewatering the solution by
spraying. The decahydrate complexes heavy metal salts
and water hardeners and therefore reduces the hardness
15 of the water. Potassium diphosphate (potassium
pyrophosphate) , K4P20~, exists in the form of the
trihydrate and is a colorless, hygroscopic powder of
density 2.33 g cm-3 which is soluble in water, the pH of
the 1% strength solution at 25° being 10.4.
Condensation of NaH2P04 or of KH2P04 gives rise to
higher-molecular-mass sodium and potassium phosphates,
among which it is possible to distinguish cyclic
representatives, the sodium and potassium metaphos-
phates, and catenated types, the sodium and potassium
polyphosphates. For the latter in particular a large
number of names are in use: fused or calcined
phosphates, Graham's salt, Kurrol's and Maddrell's
salt. All higher sodium and potassium phosphates are
referred to collectively as condensed phosphates.
The industrially important pentasodium triphosphate,
Na5P301o (sodium tripolyphosphate), is a nonhygroscopic,
white, water-soluble salt which is anhydrous or
crystallizes with 6 H20 and has the general formula
Na0-[P(O)(ONa)-O]n-Na where n - 3. About 17 g of the
CA 02316591 2000-08-23
16
anhydrous salt dissolve in 100 g of water at room
temperature, at 60° about 20 g, at 100° around 32 g;
after heating the solution at 100°C for two hours,
about 8% orthophosphate and 15% diphosphate are
produced by hydrolysis. For the preparation of
pentasodium triphosphate, phosphoric acid is reacted
with sodium carbonate solution or sodium hydroxide
solution in stoichiometric ratio and the solution is
dewatered by spraying. In a similar way to Graham's
salt and sodium diphosphate, pentasodium triphosphate
dissolves numerous insoluble metal compounds (including
lime soaps, etc). Pentapotassium triphosphate, KSP301o
(potassium tripolyphosphate), is commercialized, for
example, in the form of a 50% strength by weight
solution (> 23% P205, 25% K20) . The potassium
polyphosphates find broad application in the laundry
detergent and cleaning product industry. There also
exist sodium potassium tripolyphosphates, which may
likewise be used for the purposes of the present
invention. These are formed, for example, when sodium
trimetaphosphate is hydrolyzed with KOH:
(NaP03 ) 3 + 2 KOH -~ Na3KZP301o + H20
They can be used in accordance with the invention in
precisely the same way as sodium tripolyphospate,
potassium tripolyphosphate, or mixtures of these two;
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 tripolyphospate,
may also be used in accordance with the invention.
CA 02316591 2000-08-23
17
Organic cobuilders which may be used in the tablets
are, in particular, polycarboxylates/polycarboxylic
acids, polymeric polycarboxylates, aspartic acid,
polyacetals, further organic cobuilders (see below),
and phosphonates. These classes of substance are
described below.
Organic builder substances which may be used are, for
example, the polycarboxylic acids, usable in the form
of their sodium salts, the term polycarboxylic acids
meaning those carboxylic acids which carry more than
one acid function. Examples of these are citric acid,
adipic acid, succinic acid, glutaric acid, malic acid,
tartaric acid, malefic acid, fumaric acid, sugar acids,
amino carboxylic acids, nitrilotriacetic acid (NTA),
provided such use is not objectionable on ecological
grounds, and also 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.
The acids per se may also be used. In addition to their
builder effect, the acids typically also possess the
property of an acidifying component and thus also serve
to establish a lower and milder pH of laundry
detergents or cleaning products. In this context,
mention may be made in particular of citric acid,
succinic acid, glutaric acid, adipic acid, gluconic
acid, and any desired mixtures thereof.
Also suitable as builders are polymeric poly
carboxylates; these are, for example, the alkali metal
salts of polyacrylic acid or of polymethacrylic acid,
examples being those having a relative molecular mass
of from 500 to 70,000 g/mol.
CA 02316591 2000-08-23
18
The molecular masses reported for polymeric poly-
carboxylates, for the purposes of this document, are
weight-average molecular masses, MW, of the respective
acid form, determined basically by means of gel
permeation chromatography (GPC) using a W detector.
The measurement was made against an external
polyacrylic acid standard, which owing to its
structural similarity to the polymers under
investigation provides realistic molecular weight
values. These figures differ markedly from the
molecular weight values obtained using poly-
styrenesulfonic acids as the standard. The molecular
masses measured against polystyrenesulfonic acids are
generally much higher than the molecular masses
reported in this document.
Suitable polymers are, in particular, polyacrylates,
which preferably have a molecular mass of from 2000 to
20,000 g/mol. Owing to their superior solubility,
preference in this group may be given in turn to the
short-chain polyacrylates, which have molecular masses
of from 2000 to 10,000 g/mol, and with particular
preference from 3000 to 5000 g/mol.
Also suitable are copolymeric polycarboxylates,
especially those of acrylic acid with methacrylic acid
and of acrylic acid or methacrylic acid with malefic
acid. Copolymers which have been found to be
particularly suitable are those of acrylic acid with
malefic acid which contain from 50 to 90% by weight
acrylic acid and from 50 to 10% by weight malefic acid.
Their relative molecular mass, based on free acids, is
generally from 2000 to 70,000 g/mol, preferably from
CA 02316591 2000-08-23
19
20,000 to 50,000 g/mol, and in particular from 30,000
to 40,000 g/mol.
The (co)polymeric polycarboxylates can be used either
as powders or as aqueous solutions. The (co)polymeric
polycarboxylate content of the compositions is
preferably from 0.5 to 20% by weight, in particular
from 3 to 10% by weight.
In order to improve the solubility in water, the
polymers may also contain allylsulfonic acids, such as
allyloxybenzenesulfonic acid and methallylsulfonic
acid, for example, as monomers.
Particular preference is also given to biodegradable
polymers comprising more than two different monomer
units, examples being those comprising, as monomers,
salts of acrylic acid and of malefic acid, and also
vinyl alcohol or vinyl alcohol derivatives, or those
comprising, as monomers, salts of acrylic acid and of
2-alkylallylsulfonic acid, and also sugar derivatives.
Further preferred copolymers are those described in
German Patent Applications DE-A-43 03 320 and
DE-A-44 17 734, whose monomers are preferably acrolein
and acrylic acid/acrylic acid salts, and, respectively,
acrolein and vinyl acetate.
Similarly, further preferred builder substances that
may be mentioned include polymeric amino dicarboxylic
acids, their salts or their precursor substances.
Particular preference is given to polyaspartic acids
and their salts and derivatives, which are disclosed in
German Patent Application DE-A-195 40 086 to have not
CA 02316591 2000-08-23
only cobuilder properties but also a bleach-stabilizing
action.
Further suitable builder substances are polyacetals,
5 which may be obtained by reacting dialdehydes with
polyol carboxylic acids having 5 to 7 carbon atoms and
at least 3 hydroxyl groups. Preferred polyacetals are
obtained from dialdehydes such as glyoxal,
glutaraldehyde, terephthalaldehyde and mixtures thereof
10 and from polyol carboxylic acids such as gluconic acid
and/or glucoheptonic acid.
Oxydisuccinates and other derivatives of disuccinates,
preferably ethylenediamine disuccinate, are further
15 suitable cobuilders. Ethylenediamine N,N'-disuccinate
(EDDS) is used preferably in the form of its sodium or
magnesium salts. Further preference in this context is
given to glycerol disuccinates and glycerol
trisuccinates as well. Suitable use amounts in
20 formulations containing zeolite and/or silicate are
from 3 to 15% by weight.
Examples of further useful organic cobuilders are
acetylated hydroxy carboxylic acids and their salts,
which may also be present in lactone form and which
contain at least 4 carbon atoms, at least one hydroxyl
group, and not more than two acid groups. Such
cobuilders are described, for example, in International
Patent Application WO 95/20029.
A further class of substance having cobuilder
properties is represented by the phosphonates. The
phosphonates in question are, in particular,
hydroxyalkane- and aminoalkanephosphonates. Among the
hydroxyalkanephosphonates, 1-hydroxyethane-1,1-diphos-
- CA 02316591 2000-08-23
21
phonate (HEDP) is of particular importance as a
cobuilder. It is used preferably as the sodium salt,
the disodium salt being neutral and the tetrasodium
salt giving an alkaline (pH 9) reaction. Suitable
aminoalkanephosphonates are preferably ethylenediamine-
tetramethylenephosphonate (EDTMP), diethylenetri-
aminepentamethylenephosphonate (DTPMP), and their
higher homologs. They are used preferably in the form
of the neutrally reacting sodium salts, e.g., as the
hexasodium salt of EDTMP or as the hepta- and octa-
sodium salt of DTPMP. As a builder in this case,
preference is given to using HEDP from the class of the
phosphonates. Furthermore, the aminoalkanephosphonates
possess a pronounced heavy metal binding capacity.
Accordingly, and especially if the compositions also
contain bleach, it may be preferred to use
aminoalkanephosphonates, especially DTPMP, or to use
mixtures of said phosphonates.
Furthermore, all compounds capable of forming complexes
with alkaline earth metal ions may be used as
cobuilders.
The amount of builder is usually between 10 and 70% by
weight, preferably between 15 and 60% by weight, and in
particular between 20 and 50% by weight. In turn, the
amount of builders used is dependent on the intended
use, so that bleach tablets and machine dishwashing
tablets may contain higher amounts of builders (for
example, between 20 and 70% by weight, preferably
between 25 and 65% by weight, and in particular between
30 and 55% by weight) than, say, laundry detergent
tablets (usually from 10 to 50% by weight, preferably
from 12.5 to 45% by weight, and in particular between
17.5 and 37.5% by weight).
_ CA 02316591 2000-08-23
22
Preferred laundry detergent or cleaning product tablets
of the invention further comprise one or more
surfactants. In the tablets it is possible to use
anionic, nonionic, cationic and/or amphoteric
surfactants, and/or mixtures thereof. From a
performance standpoint, preference is given to mixtures
of anionic and nonionic surfactants. The total
surfactant content of the tablets is from 5 to 60% by
weight, based on the tablet weight, preference being
given to surfactant contents of more than 15% by
weight.
Anionic surfactants used are, for example, those of the
sulfonate and sulfate type. Preferred surfactants of
the sulfonate type are C9_13 alkylbenzenesulfonates,
olefinsulfonates, i.e., mixtures of alkenesulfonates
and hydroxyalkanesulfonates, and also disulfonates, as
are obtained, for example, from Clz-la monoolefins having
a terminal or internal double bond by sulfonating with
gaseous sulfur trioxide followed by alkaline or acidic
hydrolysis of the sulfonation products. Also suitable
are alkanesulfonates, which are obtained from Clz-is
alkanes, for example, by sulfochlorination or
sulfoxidation with subsequent hydrolysis or
neutralization, respectively. Likewise suitable, in
addition, are the esters of a-sulfo fatty acids (ester
sulfonates), e.g., the a-sulfonated methyl esters of
hydrogenated coconut, palm kernel or tallow fatty
acids.
Further suitable anionic surfactants are sulfated fatty
acid glycerol esters. Fatty acid glycerol esters are
the monoesters, diesters and triesters, and mixtures
thereof, as obtained in the preparation by
CA 02316591 2000-08-23
23
esterification of a monoglycerol with from 1 to 3 mol
of fatty acid or in the transesterification of
triglycerides with from 0.3 to 2 mol of glycerol.
Preferred sulfated fatty acid glycerol esters are the
sulfation products of saturated fatty acids having 6 to
22 carbon atoms, examples being those of caproic acid,
caprylic acid, capric acid, myristic acid, lauric acid,
palmitic acid, stearic acid, or behenic acid.
Preferred alk(en)yl sulfates are the alkali metal
salts, and especially the sodium salts, of the sulfuric
monoesters of C12-Cls fatty alcohols, examples being
those of coconut fatty alcohol, tallow fatty alcohol,
lauryl, myristyl, cetyl or stearyl alcohol, or of
Clo-CZo oxo alcohols, and those monoesters of secondary
alcohols of these chain lengths. Preference is also
given to alk (en) yl sulfates of said chain length which
contain a synthetic straight-chain alkyl radical
prepared on a petrochemical basis, these sulfates
possessing degradation properties similar to those of
the corresponding compounds based on fatty-chemical raw
materials. From a detergents standpoint, the C12-Cls
alkyl sulfates and C12-C15 alkyl sulfates, and also
C14-Cis alkyl sulfates, are preferred. In addition,
2,3-alkyl sulfates, which may, for example, be prepared
in accordance with US Patents 3,234,258 or 5,075,041
and obtained as commercial products from Shell Oil
Company under the name DAN~, are suitable anionic
surfactants.
Also suitable are the sulfuric monoesters of the
straight-chain or branched C~_21 alcohols ethoxylated
with from 1 to 6 mol of ethylene oxide, such as
2-methyl-branched C9_11 alcohols containing on average
3.5 mol of ethylene oxide (EO) or Clz-la fatty alcohols
- CA 02316591 2000-08-23
24
containing from 1 to 4 EO. Because of their high
foaming behavior they are used in cleaning products
only in relatively small amounts, for example, in
amounts of from 1 to 5% by weight.
Further suitable anionic surfactants include the salts
of alkylsulfosuccinic acid, which are also referred to
as sulfosuccinates or as sulfosuccinic esters and which
constitute monoesters and/or diesters of sulfosuccinic
acid with alcohols, preferably fatty alcohols and
especially ethoxylated fatty alcohols. Preferred
sulfosuccinates comprise C8_18 fatty alcohol radicals or
mixtures thereof. Especially preferred sulfosuccinates
contain a fatty alcohol radical derived from
ethoxylated fatty alcohols which themselves represent
nonionic surfactants (for description, see below).
Particular preference is given in turn to
sulfosuccinates whose fatty alcohol radicals are
derived from ethoxylated fatty alcohols having a
narrowed homolog distribution. Similarly, it is also
possible to use alk(en)ylsuccinic acid containing
preferably 8 to 18 carbon atoms in the alk(en)yl chain,
or salts thereof.
Further suitable anionic surfactants are, in
particular, soaps. Suitable soaps include saturated
fatty acid soaps, such as the salts of lauric acid,
myristic acid, palmitic acid, stearic acid,
hydrogenated erucic acid and behenic acid, and, in
particular, mixtures of soaps derived from natural
fatty acids, e.g., coconut, palm kernel, or tallow
fatty acids.
The anionic surfactants, including the soaps, may be
present in the form of their sodium, potassium or
CA 02316591 2000-08-23
ammonium salts and also as soluble salts of organic
bases, such as mono-, di- or triethanolamine.
Preferably, the anionic surfactants are in the form of
their sodium or potassium salts, in particular in the
5 form of the sodium salts.
Nonionic surfactants used are preferably alkoxylated,
advantageously ethoxylated, especially primary,
alcohols having preferably 8 to 18 carbon atoms and on
10 average from 1 to 12 mol of ethylene oxide (EO) per
mole of alcohol, in which the alcohol radical may be
linear or, preferably, methyl-branched in position 2
and/or may comprise linear and methyl-branched radicals
in a mixture, as are customarily present in oxo alcohol
15 radicals. Particular preference is given, however, to
alcohol ethoxylates containing linear radicals from
alcohols of natural origin having 12 to 18 carbon
atoms, e.g., from coconut, palm, tallow fatty or oleyl
alcohol and on average from 2 to 8 EO per mole of
20 alcohol. Preferred ethoxylated alcohols include, for
example, Clz-14 alcohols containing 3 EO or 4 EO, C9_11
alcohol containing 7 EO, Cls-is alcohols containing 3 EO,
5 EO, 7 EO or 8 EO, Clz-is alcohols containing 3 EO, 5 EO
or 7 EO, and mixtures thereof, such as mixtures of Clz-14
25 alcohol containing 3 EO and Clz-is alcohol containing
5 EO. The stated degrees of ethoxylation represent
statistical mean values, which for a specific product
may be an integer or a fraction. Preferred alcohol
ethoxylates have a narrowed homolog distribution
(narrow range ethoxylates, NREs). In addition to these
nonionic surfactants it is also possible to use fatty
alcohols containing more than 12 EO. Examples thereof
are tallow fatty alcohol containing 14 EO, 25 EO, 30 EO
or 40 EO.
CA 02316591 2000-08-23
26
As further nonionic surfactants, furthermore, use may
also be made of alkyl glycosides of the general formula
RO(G)X, where R is a primary straight-chain or methyl-
branched aliphatic radical, especially an aliphatic
radical methyl-branched in position 2, containing 8 to
22, preferably 12 to 18, carbon atoms, and G is the
symbol representing a glycose unit having 5 or 6 carbon
atoms, preferably glucose. The degree of
oligomerization, x, which indicates the distribution of
monoglycosides and oligoglycosides, is any desired
number between 1 and 10; preferably, x is from 1.2 to
1.4.
A further class of nonionic surfactants used with
preference, which are 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 having 1 to 4 carbon atoms in the
alkyl chain, especially fatty acid methyl esters, as
are described, for example, in Japanese Patent
Application JP 58/217598, or those prepared preferably
by the process described in International Patent
Application WO-A-90/13533.
Nonionic surfactants of the amine oxide type, examples
being N-cocoalkyl-N,N-dimethylamine oxide and
N-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the
fatty acid alkanolamide type, may also be suitable. The
amount of these nonionic surfactants is preferably not
more than that of the ethoxylated fatty alcohols, in
particular not more than half thereof.
Further suitable surfactants are polyhydroxy fatty acid
amides of the formula (I),
CA 02316591 2000-08-23
27
R1
R-CO-N- [Z] (I)
where RCO is an aliphatic aryl radical having 6 to 22
carbon atoms, R1 is hydrogen or an alkyl or
hydroxyalkyl radical having 1 to 4 carbon atoms, and
[Z] is a linear or branched polyhydroxyalkyl radical
having 3 to 10 carbon atoms and from 3 to 10 hydroxyl
groups. The polyhydroxy fatty acid amides are known
substances which are customarily obtainable by
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 the polyhydroxy fatty acid amides also
includes compounds of the formula (II)
R1-O-RZ
R-CO-N- [Z] (II)
where R is a linear or branched alkyl or alkenyl
radical having 7 to 12 carbon atoms, R1 is a linear,
branched or cyclic alkyl radical or an aryl radical
having 2 to 8 carbon atoms and Rz is a linear, branched
or cyclic alkyl radical or an aryl radical or an
oxyalkyl radical having 1 to 8 carbon atoms, preference
being given to C1_4 alkyl radicals or phenyl radicals,
and [Z] is a linear polyhydroxyalkyl radical whose
alkyl chain is substituted by at least two hydroxyl
groups, or alkoxylated, preferably ethoxylated or
propoxylated, derivatives of said radical.
CA 02316591 2000-08-23
28
[Z] is preferably obtained by reductive amination of a
reduced sugar, e.g., glucose, fructose, maltose,
lactose, galactose, mannose, or xylose. The N-alkoxy-
or N-aryloxy-substituted compounds may then be
converted to the desired polyhydroxy fatty acid amides,
for example, in accordance with the teaching of
International Application YJO-A-95/07331 by reaction
with fatty acid methyl esters in the presence of an
alkoxide as catalyst.
In the context of the present invention, preference is
given to laundry detergent and cleaning product tablets
comprising anionic and nonionic surfactant(s);
performance advantages may result from certain
proportions in which the individual classes of
surfactant are used.
For example, particular preference is given to tablets
in which the ratio of anionic surfactants) to nonionic
surfactants) is between 10:1 and 1:10, preferably
between 7.5:1 and 1:5, and in particular between 5:1
and 1:2. Preference is also given to laundry detergent
and cleaning product tablets comprising anionic and/or
nonionic surfactants) and having overall surfactant
contents of more than 2.5% by weight, preferably more
than 5% by weight, and in particular more than 10% by
weight, based in each case on the tablet weight.
Particularly preferred are laundry detergent and
cleaning product tablets comprising surfactant(s),
preferably anionic and/or nonionic surfactant(s), in
amounts of from 5 to 40% by weight, preferably from 7.5
to 35% by weight, with particular preference from 10 to
30% by weight, and in particular from 12.5 to 25% by
weight, based in each case on the tablet weight.
CA 02316591 2000-08-23
29
From a performance standpoint, it may be advantageous
if certain classes of surfactant are absent from some
phases of the tablets or from the tablet as a whole,
i.e., from all phases. A further important embodiment
of the present invention therefore envisages that at
least one phase of the tablets is free from nonionic
surfactants .
Conversely, however, the presence of certain
surfactants in individual phases or in the whole
tablet, i.e., in all phases, may produce a positive
effect. The incorporation of the above-described alkyl
polyglycosides has been found advantageous, and so
preference is given to tablets wherein at least one
phase of the tablets comprises alkyl polyglycosides.
Similarly to the case with the nonionic surfactants,
the omission of anionic surfactants from certain phases
or all phases may also result in tablets better suited
to certain fields of application. In the context of the
present invention, therefore, it is also possible to
conceive of laundry detergent and cleaning product
tablets in which at least one phase of the tablets is
free from anionic surfactants.
As already mentioned, the use of surfactants in the
case of cleaning product tablets for machine
dishwashing is preferably limited to the use of
nonionic surfactants in small amounts. Laundry
detergent and cleaning product tablets preferred for
use as cleaning product tablets in the context of the
present invention are those wherein the tablet has
total surfactant contents of less than 5% by weight,
preferably less than 4% by weight, with particular
CA 02316591 2000-08-23
preference less than 3% by weight, and in particular
less than 2% by weight, based in each case on the
weight of the tablet. Surfactants used in machine
dishwashing compositions are usually only low-foaming
5 nonionic surfactants. Representatives from the groups
of the anionic, cationic and amphoteric surfactants, in
contrast, are of relatively little importance. With
particular preference, the cleaning product tablets of
the invention for machine dishwashing comprise nonionic
10 surfactants, especially nonionic surfactants from the
group of the alkoxylated alcohols. Preferred nonionic
surfactants used are alkoxylated, advantageously
ethoxylated, especially primary, alcohols having
preferably 8 to 18 carbon atoms and on average from 1
15 to 12 mol of ethylene oxide (EO) per mole of alcohol,
in which the alcohol radical may be linear or,
preferably, methyl-branched in position 2 and/or may
comprise linear and methyl-branched radicals in a
mixture, as are customarily present in oxo alcohol
20 radicals. Particular preference is given, however, to
alcohol ethoxylates containing linear radicals from
alcohols of natural origin having 12 to 18 carbon
atoms, e.g., from coconut, palm, tallow fatty or oleyl
alcohol and on average from 2 to 8 EO per mole of
25 alcohol. Preferred ethoxylated alcohols include, for
example, Cla-14 alcohols containing 3 EO or 4 EO, C9_11
alcohol containing 7 EO, C13-is alcohols containing 3 EO,
5 EO, 7 EO or 8 EO, Cla-le alcohols containing 3 EO, 5 EO
or 7 EO, and mixtures thereof, such as mixtures of Cla-i4
30 alcohol containing 3 EO and Clz-la alcohol containing
5 EO. The stated degrees of ethoxylation represent
statistical mean values, which for a specific product
may be an integer or a fraction. Preferred alcohol
ethoxylates have a narrowed homolog distribution
(narrow range ethoxylates, NREs). In addition to these
CA 02316591 2000-08-23
31
nonionic surfactants, it is also possible to use fatty
alcohols containing more than 12 EO. Examples thereof
are tallow fatty alcohol containing 14 EO, 25 EO,
30 EO, or 40 EO.
Especially in connection with novel laundry detergent
tablets or detergent tablets for machine dishwashing,
it is preferred for the laundry detergent and cleaning
product tablets to comprise a nonionic surfactant
having a melting point above room temperature.
Accordingly, the laundry detergent and cleaning product
tablets of the invention preferably comprise a nonionic
surfactant having a melting point above 20°C. Nonionic
surfactants whose use is preferred have melting points
above 25°C, nonionic surfactants whose use is
particularly preferred have melting points of between
and 60°C, in particular between 26.6 and 43.3°C.
Suitable nonionic surfactants having melting or
20 softening points within the stated temperature range
are, for example, low-foaming nonionic surfactants
which may be solid or highly viscous at room
temperature. If nonionic surfactants which are highly
viscous at room temperature are used, then their
25 preferred viscosity is above 20 Pas, preferably above
Pas, and in particular above 40 Pas. Also preferred
are nonionic surfactants which possess a waxlike
consistency at room temperature.
3C Preferred nonionic surfactants for use that are solid
at room temperature originate from the groups of the
alkoxylated nonionic surfactants, especially the
ethoxylated primary alcohols, and mixtures of these
surfactants with surfactants of more complex
35 construction such as polyoxypropylene/polyoxyethylene/
CA 02316591 2000-08-23
32
polyoxypropylene (PO/EO/PO) surfactants. Such
(PO/EO/PO) nonionic surfactants are notable,
furthermore, for good foam control.
In one preferred embodiment of the present invention,
the nonionic surfactant having a melting point above
room temperature is an ethoxylated nonionic surfactant
originating from the reaction of a monohydroxy alkanol
or alkylphenol having 6 to 20 carbon atoms with
preferably at least 12 mol, with particular preference
at least 15 mol, in particular at least 20 mol, of
ethylene oxide per mole of alcohol or alkylphenol,
respectively.
A particularly preferred nonionic surfactant for use
that is solid at room temperature is obtained from a
straight-chain fatty alcohol having 16 to 20 carbon
atoms (Cls-zo alcohol) , preferably a C18 alcohol, and at
least 12 mol, preferably at least 15 mol, and in
particular at least 20 mol, of ethylene oxide. Of
these, the so-called "narrow range ethoxylates" (see
above) are particularly preferred.
The nonionic surfactant which is solid at room
temperature preferably further possesses propylene
oxide units in the molecule. Preferably, such PO units
account for up to 25% by weight, with particular
preference up to 20% by weight, and in particular up to
15% by weight, of the overall molar mass of the
nonionic surfactant. Particularly preferred nonionic
surfactants are ethoxylated monohydroxy alkanols or
alkylphenols which additionally comprise polyoxy-
ethylene-polyoxypropylene block copolymer units. The
alcohol or alkylphenol moiety of such nonionic
surfactant molecules in this case makes up preferably
CA 02316591 2000-08-23
33
more than 30% by weight, with particular preference
more than 50% by weight, and in particular more than
70% by weight, of the overall molar mass of such
nonionic surfactants.
Further nonionic surfactants whose use is particularly
preferred have melting points above room temperature,
contain from 40 to 70% of a polyoxypropylene/polyoxy-
ethylene/polyoxypropylene block polymer blend which
comprises 75% by weight of an inverted block copolymer
of polyoxyethylene and polyoxypropylene containing
17 mol of ethylene oxide and 44 mol of propylene oxide
and 25% by weight of a block copolymer of
polyoxyethylene and polyoxypropylene, initiated with
trimethylolpropane and containing 24 mol of ethylene
oxide and 99 mol of propylene oxide per mole of
trimethylolpropane.
Nonionic surfactants which may be used with particular
preference are, for example, obtainable under the name
Poly Tergent~ SLF-18 from the company Olin Chemicals.
A further preferred surfactant may be described by the
formula
R10 [CHzCH (CH3) O] X [CHzCH20] y [CH2CH (OH) RZ]
in which R1 is a linear or branched aliphatic
hydrocarbon radical having 4 to 18 carbon atoms, or
mixtures thereof, R2 is a linear or branched
hydrocarbon radical having 2 to 26 carbon atoms, or
mixtures thereof, and x is between 0.5 and 1.5, and y
is at least 15.
_ CA 02316591 2000-08-23
34
Further nonionic surfactants which may be used with
preference are the endgroup-capped poly(oxyalkylated)
nonionic surfactants of the formula
R10 [CHZCH (R3) O] X [CHZ] kCH (OH) [CHz] ~OR2
in which R1 and R2 are linear or branched, saturated or
unsaturated, aliphatic or aromatic hydrocarbon radicals
having 1 to 30 carbon atoms, R3 is H or a methyl,
ethyl, n-propyl, isopropyl, n-butyl, 2-butyl or 2-
methyl-2-butyl radical, x is between 1 and 30, k and j
are between 1 and 12, preferably between 1 and 5. Where
x >_ 2, each R3 in the above formula may be different. R1
and R2 are preferably linear or branched, saturated or
unsaturated, aliphatic or aromatic hydrocarbon radicals
having 6 to 22 carbon atoms, radicals having 8 to 18
carbon atoms being particularly preferred. For the
radical R3, H, -CH3 or -CHzCH3 are particularly
preferred. Particularly preferred values for x lie
within the range from 1 to 20, in particular from 6 to
15.
As described above, each R3 in the above formula may be
different if x >_ 2. By this means it is possible to
vary the alkylene oxide unit in the square brackets. If
x, for example, is 3, the radical R3 may be selected in
order to form ethylene oxide (R3 - H), or propylene
oxide (R3 - CH3) units, which may be added on to one
another in any sequence, examples being (EO)(PO)(EO),
(EO) (EO) (PO) , (EO) (EO) (EO) , (PO) (EO) (PO) , (PO) (PO) (EO)
and (PO) (PO) (PO) . The value of 3 for x has been chosen
by way of example in this case and it is entirely
possible for it to be larger, the scope for variation
increasing as the values of x go up and embracing, for
CA 02316591 2000-08-23
example, a large number of (EO) groups, combined with a
small number of (PO) groups, or vice versa.
Particularly preferred endgroup-capped poly(oxy-
5 alkylated) alcohols of the above formula have values of
k = 1 and j - 1, thereby simplifying the above formula
to
R10 [ CHz CH ( R3 ) O ] XCHZ CH ( OH ) CH20Rz
In the last-mentioned formula, R1, Rz and R3 are as
defined above and x stands for numbers from 1 to 30,
preferably from 1 to 20, and in particular from 6 to
18. Particular preference is given to surfactants
wherein the radicals R1 and R2 have 9 to 14 carbon
atoms, R3 is H, and x adopts values from 6 to 15.
In order to facilitate the disintegration of highly
compacted tablets, it is possible to incorporate
disintegration aids, known as tablet disintegrants,
into the tablets in order to reduce the disintegration
times. Tablet disintegrants, or disintegration
accelerators, are understood in accordance with Rompp
(9th Edition, Vol. 6, p. 4440) and Voigt "Lehrbuch der
pharmazeutischen Technologie" [Textbook of
pharmaceutical technology] (6th Edition, 1987,
pp. 182-184) to be auxiliaries which ensure the rapid
disintegration of tablets in water or gastric fluid and
the release of the drugs in absorbable form.
These substances increase in volume on ingress of
water, with on the one hand an increase in the
intrinsic volume (swelling) and on the other hand, by
way of the release of gases, the generation of a
pressure which causes the tablets to disintegrate into
- CA 02316591 2000-08-23
36
smaller particles. Examples of established
disintegration aids are carbonate/citric acid systems,
with the use of other organic acids also being
possible. Examples of swelling disintegration aids are
synthetic polymers such as polyvinylpyrrolidone (PVP)
or natural polymers and/or modified natural substances
such as cellulose and starch and their derivatives,
alginates, or casein derivatives.
Preferred laundry detergent or cleaning product tablets
contain from 0.5 to 10% by weight, preferably from 3 to
7% by weight, and in particular from 4 to 6% by weight,
of one or more disintegration aids, based in each case
on the tablet weight.
Preferred disintegrants used in the context of the
present invention are cellulose-based disintegrants and
so preferred tablets comprise a cellulose-based
disintegrant of this kind in amounts from 0.5 to 10% by
weight, preferably from 3 to 7% by weight, and in
particular from 4 to 6% by weight. Pure cellulose has
the formal empirical composition (C6H1o05) n and,
considered formally, is a (3-1,4-polyacetal of
cellobiose, which itself is constructed of two
molecules of glucose. Suitable celluloses consist of
from about 500 to 5000 glucose units and, accordingly,
have average molecular masses of from 50,000 to
500,000. Cellulose-based disintegrants which can be
used also include, in the context of the present
invention, cellulose derivatives obtainable by polymer-
analogous reactions from cellulose. Such chemically
modified celluloses include, for example, products of
esterifications and etherifications in which hydroxy
hydrogen atoms have been substituted. However,
celluloses in which the hydroxy groups have been
CA 02316591 2000-08-23
37
replaced by functional groups not attached by an oxygen
atom may also be used as cellulose derivatives. The
group of the cellulose derivatives embraces, for
example, alkali metal celluloses, carboxymethyl-
cellulose (CMC), cellulose esters and cellulose ethers
and aminocelluloses. Said cellulose derivatives are
preferably not used alone as cellulose-based
disintegrants but instead are used in a mixture with
cellulose. The cellulose derivative content of these
mixtures is preferably less than 50% by weight, with
particular preference less than 20% by weight, based on
the cellulose-based disintegrant. The particularly
preferred cellulose-based disintegrant used is pure
cellulose, free from cellulose derivatives.
The cellulose used as disintegration aid is preferably
not used in finely divided form but instead is
converted into a coarser form, for example, by
granulation or compaction, before being admixed to the
premixes intended for compression. Laundry detergent
and cleaning product tablets comprising disintegrants
in granular or optionally cogranulated form are
described in German Patent Applications
DE 197 09 991 (Stefan Herzog) and DE 197 10 254
(Henkel) and in International Patent Application
W098/40463 (Henkel). These documents also provide
further details on the production of granulated,
compacted or cogranulated cellulose disintegrants. The
particle sizes of such disintegrants are usually above
200 Vim, preferably between 300 and 1600 ~m to the
extent of at least 90% by weight, and in particular
between 400 and 1200 ~m to the extent of at least 90%
by weight. The abovementioned, relatively coarse
disintegration aids, and those described in more detail
in the cited documents, are preferred for use as
CA 02316591 2000-08-23
38
cellulose-based disintegration aids in the context of
the present invention and are available commercially,
for example, under the designation Arbocel~ TF-30-HG
from the company Rettenmaier.
As a further cellulose-based disintegrant or as a
constituent of this component, it is possible to use
microcrystalline cellulose. This microcrystalline
cellulose is obtained by partial hydrolysis of
celluloses under conditions which attack only the
amorphous regions (approximately 30% of the total
cellulose mass) of the celluloses and break them up
completely but leave the crystalline regions
(approximately 70%) intact. Subsequent deaggregation of
the microfine celluloses resulting from the hydrolysis
yields the microcrystalline celluloses, which have
primary particle sizes of approximately 5 ~m and can be
compacted, for example, to granules having an average
particle size of 200 Vim.
Laundry detergent and cleaning product tablets which
are preferred in the context of the present invention
further comprise a disintegration aid, preferably a
cellulose-based disintegration aid, preferably in
granular, cogranulated or compacted form, in amounts of
from 0 . 5 to 10 % by weight, preferably from 3 to 7% by
weight, and in particular from 4 to 6% by weight, based
in each case on the tablet weight, with preferred
disintegration aids having average particle sizes of
more than 300 Vim, preferably more than 400 Vim, and in
particular more than 500 Vim.
The laundry detergent and cleaning product tablets of
the invention may further comprise a gas-evolving
effervescent system. Said gas-evolving effervescent
CA 02316591 2000-08-23
39
system may consist of a single substance which on
contact with water releases a gas. Among these
compounds mention may be made, in particular, of
magnesium peroxide, which on contact with water
releases oxygen. Normally, however, the gas-releasing
effervescent system consists in turn of at least two
constituents which react with one another and, in so
doing, form gas. Although a multitude of systems which
release, for example, nitrogen, oxygen or hydrogen are
conceivable and implementable here, the effervescent
system used in the laundry detergent and cleaning
product tablets of the invention will be selectable on
the basis of both economic and environmental
considerations. Preferred effervescent systems consist
of alkali metal carbonate and/or alkali metal hydrogen
carbonate and of an acidifier apt to release carbon
dioxide from the alkali metal salts in aqueous
solution.
Among the alkali metal carbonates and/or alkali metal
hydrogen carbonates, the sodium and potassium salts are
much preferred over the other salts for reasons of
cost. It is of course not mandatory to use the single
alkali metal carbonates or alkali metal hydrogen
carbonates in question; rather, mixtures of different
carbonates and hydrogen carbonates may be preferred
from the standpoint of wash technology.
In preferred laundry detergent and cleaning product
tablets, the effervescent system used comprises from 2
to 20% by weight, preferably from 3 to 15% by weight,
and in particular from 5 to 10% by weight, of an alkali
metal carbonate or alkali metal hydrogen carbonate, and
from 1 to 15, preferably from 2 to 12, and in
_ CA 02316591 2000-08-23
particular from 3 to 10, % by weight of an acidifier,
based in each case on the total tablet.
As examples of acidifiers which release carbon dioxide
5 from the alkali metal salts in aqueous solution it is
possible to use boric acid and also alkali metal
hydrogen sulfates, alkali metal hydrogen phosphates,
and other inorganic salts. Preference is given,
however, to the use of organir_ acidifiers, with citric
10 acid being a particularly preferred acidifier. However,
it is also possible, in particular, to use the other
solid mono-, oligo- and polycarboxylic acids. Preferred
among this group, in turn, are tartaric acid, succinic
acid, malonic acid, adipic acid, malefic acid, fumaric
15 acid, oxalic acid, and polyacrylic acid. Organic
sulfonic acids such as amidosulfonic acid may likewise
be used. A commercially available acidifier which is
likewise preferred for use in the context of the
present invention is Sokalan~ DCS (trademark of BASF),
20 a mixture of succinic acid (max. 31% by weight),
glutaric acid (max. 50% by weight), and adipic acid
(max. 33% by weight).
In addition to the abovementioned constituents,
25 builder, surfactant and disintegration aid, the laundry
detergent and cleaning product tablets of the invention
may further comprise further customary laundry
detergent and cleaning product ingredients from the
group consisting of bleaches, bleach activators, dyes,
30 fragrances, optical brighteners, enzymes, foam
inhibitors, silicone oils, antiredeposition agents,
graying inhibitors, color transfer inhibitors, and
corrosion inhibitors.
- CA 02316591 2000-08-23
41
To develop the desired bleaching performance, the
laundry detergent and cleaning product tablets of the
present invention may comprise bleaches. For this
purpose, the customary bleaches from the group
consisting of sodium perborate monohydrate, sodium
perborate tetrahydrate, and sodium percarbonate, in
particular, have proven useful.
"Sodium percarbonate" is a term used unspecifically for
sodium carbonate peroxohydrates, which strictly
speaking are not "percarbonates" (i.e., salts of
percarbonic acid) but rather hydrogen peroxide adducts
onto sodium carbonate. The commercial product has the
average composition 2 Na2C03 ~ 3 Hz02 and is thus not a
peroxycarbonate. Sodium percarbonate forms a white,
water soluble powder of density 2.14 g cm-3 which breaks
down readily into sodium carbonate and oxygen having a
bleaching or oxidizing action.
Sodium carbonate peroxohydrate was first obtained in
1899 by precipitation with ethanol from a solution of
sodium carbonate in hydrogen peroxide, but was
mistakenly regarded as peroxycarbonate. Only in 1909
was the compound recognized as the hydrogen peroxide
addition compound; nevertheless, the historical name
"sodium percarbonate" has persisted in the art.
Industrially, sodium percarbonate is produced
predominantly by precipitation from aqueous solution
(known as the wet process). In this process, aqueous
solutions of sodium carbonate and hydrogen peroxide are
combined and the sodium percarbonate is precipitated by
means of salting agents (predominantly sodium
chloride), crystallizing aids (for example poly-
phosphates, polyacrylates), and stabilizers (for
. CA 02316591 2000-08-23
42
example, Mg2+ ions) . The precipitated salt, which still
contains from 5 to 12% by weight of the mother liquor,
is subsequently centrifuged and dried in fluidized-bed
dryers at 90°C. The bulk density of the finished
product may vary between 800 and 1200 g/1 according to
the production process. Generally, the percarbonate is
stabilized by an additional coating. Coating processes,
and substances used for the coating, are amply
described in the patent literature. Fundamentally, it
is possible in accordance with the invention to use all
commercially customary percarbonate types, as supplied,
for example, by the companies Solvay Interox, Degussa,
Kemira or Akzo.
With the bleaches used, the amount of these substances
in the tablets is dependent on the intended use of the
tablets. Whereas customary universal laundry detergents
in tablet form contain between 5 and 30% by weight,
preferably between 7.5 and 25% by weight, and in
particular between 12.5 and 22.5% by weight of bleach,
the amounts in the case of bleach tablets or bleach
booster tablets are between 15 and 50% by weight,
preferably between 22.5 and 45% by weight, and in
particular between 30 and 40% by weight.
In addition to the bleaches used, the laundry detergent
and cleaning product tablets of the invention may
comprise bleach activator(s), which is preferred in the
context of the present invention. Bleach activators are
incorporated into laundry detergents and cleaning
products in order to achieve an improved bleaching
action when washing at temperatures of 60°C or below.
Bleach activators which may be used are compounds which
under perhydrolysis conditions give rise to aliphatic
peroxo carboxylic acids having preferably 1 to 10
CA 02316591 2000-08-23
43
carbon atoms, in particular 2 to 4 carbon atoms, and/or
substituted or unsubstituted perbenzoic acid. Suitable
substances are those which carry O-acyl and/or N-acyl
groups of the stated number of carbon atoms, and/or
substituted or unsubstituted benzoyl groups. Preference
is given to polyacylated alkylenediamines, especially
tetraacetylethylenediamine (TAED), acylated triazine
derivatives, especially 1,5-diacetyl-2,4-dioxohexa-
hydro-1,3,5-triazine (DADHT), acylated glycolurils,
especially tetraacetylglycoluril (TAGU), N-acyl imides,
especially N-nonanoylsuccinimide (NOSI), acylated
phenolsulfonates, especially n-nonanoyl- or
isononanoyloxybenzenesulfonate (n- or iso-NOBS),
carboxylic anhydrides, especially phthalic anhydride,
acylated polyhydric alcohols, especially triacetin,
ethylene glycol diacetate, and 2,5-diacetoxy-2,5-
dihydrofuran.
In addition to the conventional bleach activators, or
instead of them, it is also possible to incorporate
what are known as bleaching catalysts into the tablets.
These substances are bleach-boosting transition metal
salts or transition metal complexes such as, for
example, Mn-, Fe-, Co-, Ru- or Mo-salen complexes or
-carbonyl complexes. Other bleaching catalysts which
can be used include Mn, Fe, Co, Ru, Mo, Ti, V and Cu
complexes with N-containing tripod ligands, and also
Co-, Fe-, Cu- and Ru-ammine complexes.
If the tablets of the invention comprise bleach
activators, they comprise - based in each case on the
total tablet - between 0.5 and 30% by weight,
preferably between 1 and 20% by weight, and in
particular between 2 and 15% by weight, of one or more
bleach activators or bleach catalysts. These amounts
. CA 02316591 2000-08-23
44
may vary depending on the intended use of the tablets
produced. In typical universal laundry detergent
tablets, for instance, bleach activator contents of
between 0.5 and 10% by weight, preferably between 2 and
8% by weight, and in particular between 4 and 6% by
weight, are customary, whereas bleach tablets may
contain consistently larger amounts, for example,
between 5 and 30% by weight, preferably between 7.5 and
25% by weight, and in particular between 10 and 20% by
weight . In this context there is no restriction on the
freedom of the skilled worker to formulate, and he or
she is able in this way to produce laundry detergent
tablets, cleaning product tablets or bleach tablets
with a stronger or weaker bleaching action by varying
the amounts of bleach activator and bleach.
One bleach activator used with particular preference is
N,N,N',N'-tetraacetylethylenediamine, which is widely
used in laundry detergents and cleaning products.
Accordingly, preferred laundry detergent and cleaning
product tablets are those wherein tetraacetylethylene-
diamine is used as bleach activator in the amounts
specified above.
In addition to the abovementioned constituents, bleach,
bleach activator, builder, surfactant, and
disintegration aid, the laundry detergent and cleaning
product tablets of the invention may comprise further
customary laundry detergent and cleaning product
ingredients from the group consisting of dyes,
fragrances, optical brighteners, enzymes, foam
inhibitors, silicone oils, antiredeposition agents,
graying inhibitors, color transfer inhibitors, and
corrosion inhibitors.
CA 02316591 2000-08-23
In order to enhance the esthetic appeal of the laundry
detergent and cleaning product tablets of the
invention, they may be colored with appropriate dyes.
Preferred dyes, whose selection presents no difficulty
5 whatsoever to the skilled worker, possess a high level
of storage stability and insensitivity to the other
ingredients of the compositions and to light and
possess no pronounced affinity for textile fibers, so
as not to stain them.
Preference for use in the laundry detergent and
cleaning product tablets of the invention is given to
all colorants which can be oxidatively destroyed in the
wash process, and to mixtures thereof with suitable
blue dyes, known as bluing agents. It has proven
advantageous to use colorants which are soluble in
water or at room temperature in liquid organic
substances. Examples of suitable colorants are anionic
colorants, e.g., anionic nitroso dyes. One possible
colorant is, for example, naphthol green (Colour Index
(CI) Part 1: Acid Green l; Part 2: 10020) which as a
commercial product is obtainable, for example, as
Basacid~ Green 970 from BASF, Ludwigshafen, and also
mixtures thereof with suitable blue dyes. Further
suitable colorants include Pigmosol~ Blue 6900
(CI 74160), Pigmosol~ Green 8730 (CI 74260), Basonyl~
Red 545 FL (CI 45170), Sandolan~ Rhodamin EB400
(CI 45100), Basacid° Yellow 094 (CI 47005), Sicovit~
Patent Blue 85 E 131 (CI 42051), Acid Blue 183
(CAS 12217-22-0, CI Acid Blue 183), Pigment Blue 15
(CI 74160), Supranol~ Blue GLW (CAS 12219-32-8, CI Acid
Blue 221), Nylosan° Yellow N-7GL SGR (CAS 61814-57-l,
CI Acid Yellow 218) and/or Sandolan~ Blue (CI Acid Blue
182, CAS 12219-26-0).
CA 02316591 2000-08-23
46
In the context of the choice of colorant it must be
ensured that the colorants do not have too great an
affinity for the textile surfaces, and especially for
synthetic fibers. At the same time, it should also be
borne in mind in choosing appropriate colorants that
colorants possess different stabilities with respect to
oxidation. The general rule is that water-insoluble
colorants are more stable to oxidation than water-
soluble colorants. Depending on the solubility and
hence also on the oxidation sensitivity, the
concentration of the colorant in the laundry detergents
or cleaning products varies. With readily water-soluble
colorants, e.g., the abovementioned Basacid~ Green, or
the likewise abovementioned Sandolan~ Blue, colorant
concentrations chosen are typically in the range from a
few 10-2 to 10-3% by weight . In the case of the pigment
dyes, which are particularly preferred for reason of
their brightness but are less readily soluble in water,
examples being the abovementioned Pigmosol~ dyes, the
appropriate concentration of the colorant in laundry
detergents or cleaning products, in contrast, is
typically from a few 10-3 to 10-4% by weight .
The tablets may comprise optical brighteners of the
type of the derivatives of diaminostilbenedisulfonic
acid and/or the alkali metal salts thereof. Examples of
suitable brighteners are salts of 4,4'-bis(2-anilino-4-
morpholino-1,3,5-triazinyl-6-amino)stilbene-2,2'-di-
sulfonic acid or compounds of similar structure which
instead of the morphilino group carry a diethanolamino
group, a methylamino group, an anilino group, or a
2-methoxyethylamino group. Furthermore, brighteners of
the substituted diphenylstyryl type may be present,
examples being the alkali metal salts of 4,4'-bis(2-
sulfostyryl)biphenyl, 4,4'-bis(4-chloro-3-sulfostyryl)-
CA 02316591 2000-08-23
47
biphenyl, or 4-(4-chlorostyryl)-4'-(2-sulfostyryl)-
biphenyl. Mixtures of the abovementioned brighteners
may also be used. In the laundry detergent and cleaning
product tablets of the invention, the optical
brighteners are used in concentrations of between 0.01
and 1% by weight, preferably between 0.05 and 0.5% by
weight, and in particular between 0.1 and 0.25% by
weight, based in each case on the total tablet.
Fragrances are added to the compositions of the
invention in order to enhance the esthetic appeal of
the products and to provide the consumer with not only
the performance of the product but also a visually and
sensorially "typical and unmistakable" product. As
perfume oils and/or fragrances it is possible to use
individual odorant compounds, examples being the
synthetic products of the ester, ether, aldehyde,
ketone, alcohol, and hydrocarbon types. Odorant
compounds of the ester type are, for example, benzyl
acetate, phenoxyethyl isobutyrate, p-tert-butylcyclo-
hexyl acetate, linalyl acetate, dimethylbenzylcarbinyl
acetate, phenylethyl acetate, linalyl benzoate, benzyl
formate, ethyl methylphenylglycinate, allyl cyclo-
hexylpropionate, styrallyl propionate, and benzyl
salicylate. The ethers include, for example, benzyl
ethyl ether; the aldehydes include, for example, the
linear alkanals having 8-18 carbon atoms, citral,
citronellal, citronellyloxyacetaldehyde, cyclamen
aldehyde, hydroxycitronellal, lilial and bourgeonal;
the ketones include, for example, the ionones,
oc-isomethylionone and methyl cedryl ketone; the
alcohols include anethol, citronellol, eugenol,
geraniol, linalool, phenylethyl alcohol, and terpineol;
the hydrocarbons include primarily the terpenes such as
limonene and pinene. Preference, however, is given to
CA 02316591 2000-08-23
48
the use of mixtures of different odorants, which
together produce an appealing fragrance note. Such
perfume oils may also contain natural odorant mixtures,
as obtainable from plant sources, examples being pine
oil, citrus oil, jasmine oil, patchouli oil, rose oil
or ylang-ylang oil. Likewise suitable are clary sage
oil, camomile oil, clove oil, balm oil, mint oil,
cinnamon leaf oil, lime blossom oil, juniperberry oil,
vetiver oil, olibanum oil, galbanum oil and labdanum
oil, and also orange blossom oil, neroli oil, orange
peel oil, and sandalwood oil.
The fragrance content of the laundry detergent and
cleaning product tablets of the invention is usually up
to 2% by weight of the overall formulation. The
fragrances may be incorporated directly into the
compositions of the invention; alternatively, it may be
advantageous to apply the fragrances to carriers which
intensify the adhesion of the perfume on the laundry
and, by means of slower fragrance release, ensure long-
lasting fragrance of the textiles. Materials which have
become established as such carriers are, for example,
cyclodextrins, it being possible in addition for the
cyclodextrin-perfume complexes to be additionally
coated with further auxiliaries.
Suitable enzymes include in particular those from the
classes of the hydrolases such as the proteases,
esterases, lipases or lipolytic enzymes, amylases,
cellulases, or other glycosyl hydrolases, and mixtures
of said enzymes. All of these hydrolases contribute in
the laundry to removing stains, such as proteinaceous,
fatty or starchy marks, and instances of graying.
Cellulases and other glycosyl hydrolases may,
furthermore, by removing pilling and microfibrils,
. CA 02316591 2000-08-23
49
contribute to color retention and to enhancing the
softness of the textile. For bleaching and/or
inhibiting color transfer, it is also possible to use
oxidoreductases. Especially suitable enzymatic active
substances are those obtained from bacterial strains or
fungi such as Bacillus subtilis, Bacillus
licheniformis, Streptomyces griseus, Coprinus cinereus
and Humicola insolens, and also from genetically
modified variants thereof. Preference is given to the
use of proteases of the subtilisin type, and especially
to proteases obtained from Bacillus lentus. Of
particular interest in this context are enzyme
mixtures, examples being those of protease and amylase
or protease and lipase or lipolytic enzymes, or of
protease and cellulase or of cellulase and lipase or
lipolytic enzymes, or of protease, amylase and lipase
or lipolytic enzymes, or of protease, lipase or
lipolytic enzymes and cellulase, but especially
protease and/or lipase-containing mixtures or mixtures
with lipolytic enzymes. Examples of such lipolytic
enzymes are the known cutinases. Peroxidases or
oxidases have also proven suitable in some cases. The
suitable amylases include, in particular, alpha-
amylases, iso-amylases, pullulanases, and pectinases.
Cellulases used are preferably cellobiohydrolases,
endoglucanases and endoglucosidases, which are also
called cellobiases, and mixtures thereof. Since
different types of cellulase differ in their CMCase and
Avicelase activities, the desired activities may be
established by means of specific mixtures of the
cellulases.
The enzymes may be adsorbed on carrier substances or
embedded in coating substances in order to protect them
against premature decomposition. The proportion of the
. CA 02316591 2000-08-23
enzymes, enzyme mixtures or enzyme granules may be, for
example, from about 0.1 to 5% by weight, preferably
from 0.5 to about 4.5% by weight.
5 In addition, the laundry detergent and cleaning product
tablets may also comprise components which have a
positive influence on the ease with which oil and fat
are washed off from textiles (these components being
known as soil repellents). This effect becomes
10 particularly marked when a textile is soiled that has
already been laundered previously a number of times
with a detergent of the invention comprising this oil-
and fat-dissolving component. The preferred oil- and
fat-dissolving components include, for example,
15 nonionic cellulose ethers such as methylcellulose and
methylhydroxypropylcellulose having a methoxy group
content of from 15 to 30% by weight and a
hydroxypropoxy group content of from 1 to 15% by
weight, based in each case on the nonionic cellulose
20 ether, and also the prior art polymers of phthalic acid
and/or terephthalic acid, and/or derivatives thereof,
especially polymers of ethylene terephthalates and/or
polyethylene glycol terephthalates or anionically
and/or nonionically modified derivatives thereof. Of
25 these, particular preference is given to the sulfonated
derivatives of phthalic acid polymers and of
terephthalic acid polymers.
The present invention further provides a process for
30 producing laundry detergent or cleaning product tablets
by shaping compression of a particulate premix, wherein
said premix comprises oxidized derivatives of starch
and/or dextrins in amounts of from 0.1 to 10% by
weight, based on the premix.
CA 02316591 2000-08-23
51
Regarding preferred oxidized derivatives of starch
and/or dextrins, reference may be made here to the
preceding remarks, as is the case regarding further
ingredients of the premix for compression or regarding
possible methods of incorporating the oxidized
derivatives of starch and/or dextrins.
The tablets of the invention are produced first of all
by dry-mixing the constituents, some or all of which
may have been pregranulated, and subsequently shaping
the dry mixture, in particular by compression to
tablets, in which context it is possible to have
recourse to conventional processes. To produce the
tablets, the premix is compacted in a so-called die
between two punches to form a solid compact. This
operation, which is referred to below for short as
tableting, is divided into four sections: metering,
compaction (elastic deformation), plastic deformation,
and ejection.
First of all, the premix is introduced into the die,
the fill level and thus the weight and form of the
resulting tablet being determined by the position of
the lower punch and by the form of the compression
tool. Even in the case of high tablet throughputs,
constant metering is preferably achieved by volumetric
metering of the premix. In the subsequent course of
tableting, the upper punch contacts the premix and is
lowered further in the direction of the lower punch. In
the course of this compaction the particles of the
premix are pressed closer to one another, with a
continual reduction in the void volume within the
filling between the punches. When the upper punch
reaches a certain position (and thus when a certain
pressure is acting on the premix), plastic deformation
CA 02316591 2000-08-23
52
begins, in which the particles coalesce and the tablet
is formed. Depending on the physical properties of the
premix, a portion of the premix particles is also
crushed and at even higher pressures there is sintering
of the premix. With an increasing compression rate,
i.e., high throughputs, the phase of elastic
deformation becomes shorter and shorter, with the
result that the tablets formed may have larger or
smaller voids. In the final step of tableting, the
finished tablet is ejected from the die by the lower
punch and conveyed away by means of downstream
transport means. At this point in time, it is only the
weight of the tablet which has been ultimately defined,
since the compacts may still change their form and size
as a result of physical processes (elastic relaxation,
crystallographic effects, cooling, etc).
Tableting takes place in commercially customary
tableting presses, which may in principle be equipped
with single or double punches. In the latter case,
pressure is built up not only using the upper punch;
the lower punch as well moves toward the upper punch
during the compression operation, while the upper punch
presses downward. For small production volumes it is
preferred to use eccentric tableting presses, in which
the punch or punches is or are attached to an eccentric
disk, which in turn is mounted on an axle having a
defined speed of rotation. The movement of these
compression punches is comparable with the way in which
a customary four-stroke engine works. Compression can
take place with one upper and one lower punch, or else
a plurality of punches may be attached to one eccentric
disk, the number of die bores being increased
correspondingly. The throughputs of eccentric presses
CA 02316591 2000-08-23
53
vary, depending on model, from several hundred up to a
maximum of 3000 tablets per hour.
For greater throughputs, the apparatus chosen comprises
rotary tableting presses, in which a relatively large
number of dies is arranged in a circle on a so-called
die table. Depending on model, the number of dies
varies between 6 and 55, larger dies also being
obtainable commercially. Each die on the die table is
allocated an upper punch and a lower punch, it being
possible again for the compressive pressure to be built
up actively by the upper punch or lower punch only or
else by both punches. The die table and the punches
move around a common, vertical axis, and during
rotation the punches, by means of raillike cam tracks,
are brought into the positions for filling, compaction,
plastic deformation, and ejection. At those sites where
considerable raising or lowering of the punches is
necessary (filling, compaction, ejection), these cam
tracks are assisted by additional low-pressure
sections, low tension rails, and discharge tracks. The
die is filled by way of a rigid supply means, known as
the filling shoe, which is connected to a stock vessel
for the premix. The compressive pressure on the premix
can be adjusted individually for upper punch and lower
punch by way of the compression paths, the buildup of
pressure taking place by the rolling movement of the
punch shaft heads past displaceable pressure rolls.
In order to increase the throughput, rotary presses may
also be provided with two filling shoes, in which case
only one half-circle need be traveled to produce one
tablet. For the production of two-layer and multilayer
tablets, a plurality of filling shoes are arranged in
series, and the gently pressed first layer is not
CA 02316591 2000-08-23
54
ejected before further filling. By means of an
appropriate process regime it is possible in this way
to produce laminated tablets and inlay tablets as well,
having a construction like that of an onion skin, where
in the case of the inlay tablet the top face of the
core or of the core layers is not covered and therefore
remains visible. Rotary tableting presses can also be
equipped with single or multiple tools, so that, for
example, an outer circle with 50 bores and an inner
circle with 35 bores can be used simultaneously for
compression. The throughputs of modern rotary tableting
presses amount to more than a million tablets per hour.
When tableting with rotary presses it has been found
advantageous to perform tableting with minimal
fluctuations in tablet weight. Fluctuations in tablet
hardness can also be reduced in this way. Slight
fluctuations in weight can be achieved as follows:
- use of plastic inserts with small thickness tolerances
-low rotor speed
- large filling shoes
- harmonization between the filling shoe wing rotary
speed and the speed of the rotor
-filling shoe with constant powder height
- decoupling of filling shoe and powder charge
To reduce caking on the punches, all of the
antiadhesion coatings known from the art are available.
Polymer coatings, plastic inserts or plastic punches
are particularly advantageous. Rotating punches have
also been found advantageous, in which case, where
possible, upper punch and lower punch should be of
rotatable configuration. In the case of rotating
punches, it is generally possible to do without a
CA 02316591 2000-08-23
plastic insert . In this case the punch surfaces should
be electropolished.
It has also been found that long compression times are
5 advantageous. These times can be established using
pressure rails, a plurality of pressure rolls, or low
rotor speeds. Since the fluctuations in tablet hardness
are caused by the fluctuations in the compressive
forces, systems should be employed which limit the
10 compressive force. In this case it is possible to use
elastic punches, pneumatic compensators, or sprung
elements in the force path. In addition, the pressure
roll may be of sprung design.
15 Tableting machines suitable in the context of the
present invention are obtainable, for example, from the
following companies: Apparatebau Holzwarth GbR, Asperg,
Wilhelm Fette GmbH, Schwarzenbek, Hofer GmbH, Weil,
Horn & Noack Pharmatechnik GmbH, Worms, IMA
20 Verpackungssysteme GmbH, Viersen, KILIAN, Cologne,
KOMAGE, Kell am See, KORSCH Pressen AG, Berlin, and
Romaco GmbH, Worms. Examples of further suppliers are
Dr. Herbert Pete, Vienna (AU), Mapag Maschinenbau AG,
Berne (CH), BWI Manesty, Liverpool (GB), I. Holland
25 Ltd. , Nottingham (GB) , Courtoy N.V. , Halle (BE/LU) , and
Medicopharm, Kamnik (SI). A particularly suitable
apparatus is, for example, the hydraulic double-
pressure press HPF 630 from LAEIS, D. Tableting tools
are obtainable, for example, from the following
30 companies: Adams Tablettierwerkzeuge, Dresden, Wilhelm
Fette 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
CA 02316591 2000-08-23
56
Werkzeugbau, Tamm. Further suppliers are, for example,
Senss AG, Reinach (CH) and Medicopharm, Kamnik (SI).
The tablets can be produced in predetermined three-
s dimensional forms and predetermined sizes. Suitable
three-dimensional forms are virtually any practicable
designs - i.e., for example, bar, rod or ingot form,
cubes, blocks and corresponding three-dimensional
elements having planar side faces, and in particular
cylindrical designs with a circular or oval cross
section. This latter design covers forms ranging from
tablets through to compact cylinders having a height-
to-diameter ratio of more than 1. The tablets of the
invention may take on any geometric form whatsoever,
with particular preference being given to concave,
convex, biconcave, biconvex, cubic, tetragonal,
orthorhombic, cylindrical, spherical, cylinder-
segmentlike, discoid, tetrahedral, dodecahedral,
octahedral, conical, pyramidal, ellipsoid, pentagonal-,
heptagonal and octagonal-prismatic, and rhombohedral
forms. It is also possible to realize completely
irregular outlines such as arrow or animal forms,
trees, clouds, etc. If the inventive tablets have
corners and edges, these are preferably rounded off. As
additional visual differentiation, an embodiment having
rounded corners and beveled (chamfered) edges is
preferred.
The laundry detergent or cleaning product tablets may
in each case be formed as separate, individual elements
corresponding to the predetermined dosage of the
laundry detergents and/or cleaning products. It is
equally possible, however, to design compacts which
combine a plurality of such mass units in one compact,
with the ease of separation of smaller, portioned units
CA 02316591 2000-08-23
57
being provided for in particular by means of
predetermined breakage points. For the use of textile
laundry detergents in machines of the type customary in
Europe, with a horizontally arranged mechanism, it may
be judicious to design the portioned compacts as
tablets, in cylindrical or block form, preference being
given to a diameter/height ratio in the range from
about 0.5:2 to 2:0.5. Commercial hydraulic, eccentric
or rotary presses are suitable in particular for
producing such compacts.
The three-dimensional form of another embodiment of the
tablets is adapted in its dimensions to the dispenser
drawer of commercially customary domestic washing
machines, so that the tablets can be metered without a
dosing aid directly into the dispenser drawer, where
they dissolve during the initial rinse cycle.
Alternatively, it is of course readily possible, and
preferred in the context of the present invention, to
use the laundry detergent tablets by way of a dosing
aid.
Another preferred tablet which can be produced has a
platelike or barlike structure with, in alternation,
long, thick and short, thin segments, so that
individual segments can be broken off from this "slab"
at the predetermined breaking points, represented by
the short, thin segments, and inserted into the
machine. This principle of the "slablike" tablet
detergent may also be realized in other geometric
forms; for example, vertical triangles connected to one
another lengthwise at only one of their sides.
However, it is also possible for the various components
not to be compressed to a homogeneous tablet, but
CA 02316591 2000-08-23
58
instead to obtain tablets having a plurality of layers,
i.e., at least two layers. In this case it is also
possible for these different layers to have different
dissolution rates. This may result in advantageous
performance properties for the tablets. If, for
example, there are components present in the tablets
which have adverse effects on each other, then it is
possible to integrate one component into the quicker-
dissolving layer and the other component into a slower-
dissolving layer, so that the first component has
already reacted when the second passes into solution.
The layer structure of the tablets may be realized in
stack form, in which case dissolution of the inner
layers) at the edges of the tablet takes place at a
point when the outer layers have not yet fully
dissolved; alternatively, the inner layers) may also
be completely enveloped by the respective outerlying
layer(s), which prevents premature dissolution of
constituents of the inner layer(s).
The present invention therefore further provides a
process for producing multiphase laundry detergent or
cleaning product tablets by conventional compression of
two or more particulate premixes, wherein at least one
of the premixes comprises oxidized derivatives of
starch and/or dextrins in amounts of from 0.1 to 10% by
weight, based on the premix.
In one further-preferred embodiment of the invention, a
tablet consists of at least three layers, i.e., two
outer and at least one inner layer, with at least one
of the inner layers comprising a peroxy bleach, while
in the stack-form tablet the two outer layers, and in
the case of the envelope-form tablet the outermost
layers, are free from peroxy bleach. Furthermore, it is
CA 02316591 2000-08-23
59
also possible to provide spatial separation of peroxy
bleach and any bleach activators and/or enzymes present
in a tablet. Multilayer tablets of this kind have the
advantage that they can be used not only by way of a
dispenser drawer or by way of a metering device which
is placed into the washing liquor; instead, in such
cases it is also possible to place the tablet into the
machine in direct contact with the textiles without
fear of spotting by bleaches and the like.
In addition to the layer structure, multiphase tablets
may also be produced in the form of ring-core tablets,
core inlay tablets, or what are known as bulleye
tablets. An overview of such embodiments of multiphase
tablets is described in EP 055 100 (Jeyes Group). This
document discloses toilet cleaning product blocks
comprising a shaped body comprising a slow-soluble
cleaning product composition into which a bleach tablet
has been embedded. This document at the same discloses
the very wide variety of embodiments of multiphase
tablets, from the simple multiphase tablet through to
complex multilayer systems with inlays.
After compression, the laundry detergent and cleaning
product tablets possess high stability. The fracture
strength of cylindrical tablets can be gaged by way of
the parameter of diametral fracture stress. This
diametral fracture stress can be determined by
2P
6 =
~Dt
where a represents the diametral fracture stress (DFS)
in Pa, P is the force in N which leads to the pressure
exerted on the tablet that causes the tablet to
CA 02316591 2000-08-23
fracture, D is the tablet diameter in meters, and t is
the tablet height.
Preferred production processes for laundry detergent
5 tablets begin from granules comprising surfactant,
which are processed with other formulation components
to give a particulate premix for compression. Entirely
in analogy to the above remarks concerning preferred
ingredients of the laundry detergent and cleaning
10 product tablets of the invention, the use of further
ingredients is also to be transferred to their
production. In preferred processes, at least one
particulate premix further comprises one or more types
of granules comprising surfactant and has a bulk
15 density of at least 500 g/1, preferably at least
600 g/1, and in particular at least 700 g/l.
In preferred processes of the invention, the granules
comprising surfactant have particle sizes of between
20 100 and 2000 Vim, preferably between 200 and 1800 ~,m,
with particular preference between 400 and 1600 Vim, and
in particular between 600 and 1400 Vim.
The further ingredients of the laundry detergent and
25 cleaning product tablets of the invention may also be
incorporated into the process of the invention, and to
that extent reference is made to the above remarks.
Preferred processes are those wherein at least one
particulate premix further comprises one or more
30 substances from the group consisting of bleaches,
bleach activators, disintegration aids, enzymes, pH
modifiers, fragrances, perfume carriers, fluorescers,
dyes, foam inhibitors, silicone oils, antiredeposition
agents, optical brighteners, graying inhibitors, color
35 transfer inhibitors, and corrosion inhibitors.
CA 02316591 2000-08-23
61
As already mentioned earlier on above, one preferred
embodiment of the present invention envisages
incorporating at least some, preferably all, of the
oxidized derivatives of starch and/or dextrins that are
present invention in the tablets into the tablets of
the invention by way of granules comprising surfactant.
The present invention therefore additionally provides a
process for producing laundry detergent or cleaning
product tablets, comprising the steps of
a) preparing granules comprising surfactant and
comprising oxidized derivatives of starch and/or
dextrins,
b) blending the granules from step a) with further
ingredients of laundry detergents or cleaning
products, and
c) compressing the premix formed in step b) to give
tablets or tablet regions.
Regarding the quantitatively most important ingredients
of the surfactant granules prepared in step a) - the
surfactants and the builders, including in the present
case the oxidized derivatives of starch and/or dextrins
- reference may be made to the remarks above . Further,
optional ingredients of the surfactant granules, which
may also be part of the premix, are described later on
below. There now follow details regarding preparation
of the surfactant granules in step a) of the process of
the invention.
In selecting the appropriate machines and process
parameters for process step a), the skilled worker is
able to have recourse to literature machines and
apparatus and also technical operations, as described,
for example, in W. Pietsch "Size Enlargement by
CA 02316591 2000-08-23
62
Agglomeration", Wiley, 1991, and the literature cited
therein. The remarks below constitute only a small
proportion of the possibilities possessed by the
skilled worker for implementing this step of the
process of the invention.
As already mentioned, the preparation of surfactant
granules (corresponding to step a) of the process of
the invention) may be conducted in a large number of
customary mixing and granulating apparatuses. Examples
of mixers suitable for implementing process step a) of
the invention are Eirich° mixer of series R or RV
(trademark of Maschinenfabrik Gustav Eirich, Hardheim),
the Schugi~ Flexomix, the Fukae~ FS-G mixers (trademark
Fukae Powtech, Kogyo Co., Japan), the Lodige~ FM, KM
and CB mixers (trademark of Lodige Maschinenbau GmbH,
Paderborn), and the Drais~ series T or K-T (trademark
of Drais-Werke GmbH, Mannheim). Some preferred
embodiments of process step a) of the invention are
described hereinbelow.
For example, it is possible and preferred to implement
process step a) in a low-speed mixer/granulator at tool
tip speeds of from 2 m/s to 7 m/s. Alternatively, in
preferred process variants, process step a) may be
conducted in a high-speed mixer/granulator at tip
speeds of from 8 m/s to 35 m/s.
Irrespective of whether fast- or slow-running mixers
are used to conduct process step a), granulation in
step a) takes place preferably by agglomerative
granulation with granulating liquids. In this context,
preference is given to processes of the invention
wherein particulate solids are granulated in step a)
with the addition of one or more granulating liquids.
CA 02316591 2000-08-23
63
The oxidized derivatives of starch and/or dextrins may
in this case be either part of the bed of solids on
which granulation is to take place or else ingredients
of one or more granulating liquids. Processes of the
invention wherein the bed of solids for granulation
comprises oxidized derivatives of starch and/or
dextrins are therefore just as preferred as processes
wherein at least one of the granulating liquids applied
to the bed of solids comprises oxidized derivatives of
starch and/or dextrins.
Whereas the two above-described process variants
describe the use of in each case one mixer, it is also
possible in accordance with the invention to combine
two mixers with one another. For example, preference is
given to processes wherein a liquid granulating aid is
applied in step a) in a first, low-speed
mixer/granulator to a moving bed of solids, where from
40 to 100% by weight of the solid and liquid
constituents are pregranulated, based on the total
amount of the constituents used, and, in a second,
high-speed mixer/granulator, the pregranulated product
from the first process stage is mixed, if appropriate,
with the remaining solid and/or liquid constituents and
converted to granules. In this process variant, a
granulating aid is added to a bed of solids in the
first mixer/granulator and the mixture is
pregranulated. The composition of the granulating aid
and of the bed of solids in the first mixer is
preferably chosen so that from 40 to 100% by weight,
preferably from 50 to 90% by weight, and in particular
from 60 to 80% by weight, of the solid and liquid
constituents, based on the total amount of the
constituents used, are present in the pregranulated
CA 02316591 2000-08-23
64
product. This pregranulated product is then mixed with
further solids in the second mixer and granulation
continues, with addition of further liquid components,
to give the finished surfactant granules.
The abovementioned sequence of low-speed/high-speed
mixers may also be reversed in accordance with the
invention, giving a process of the invention wherein
the liquid granulating aid is added to a moving bed of
solids in a first, high-speed mixer/granulator, where
from 40 to 100% by weight of the solid and liquid
constituents, based on the total amount of the
constituents used, are pregranulated, and, in a second,
low-speed mixer/granulator, the pregranulated product
from the first process stage is mixed, if appropriate,
with the remaining solid and/or liquid constituents and
converted to granules.
All of the above-described variant embodiments of the
process of the invention may be conducted batchwise or
continuously. In the above-described variant
embodiments of process step a) of the invention, use is
made in part of high-speed mixer/granulators. It is
particularly preferred in the context of the present
invention that the high-speed mixer used is a mixer
having both a mixing apparatus and a comminuting
apparatus, the mixing shaft being operated at rotary
speeds of from 50 to 150 revolutions/minute, preferably
from 60 to 80 revolutions/minute, and the shaft of the
comminuting apparatus being operated at rotary speeds
of from 500 to 5000 revolutions/minute, preferably from
1000 to 3000 revolutions/minute.
Preferred granulation processes for preparing mixer
granules are conducted in mixer granulators in which
CA 02316591 2000-08-23
certain mixer parts, or the entire mixer, are, or is,
heated at temperatures at least 20°C above the
temperature possessed by the substances to be
granulated at the beginning of the granulation process.
5 If, therefore, solids stored at 20°C and entering the
mixer at this temperature are granulated, then it is
preferred for some or all mixer parts to have at least
a temperature of 40°C. Overall, however, a temperature
of 120°C should not be exceeded for the mixer parts or
10 the mixer as a whole. If only parts of the mixer are
heated to said temperatures, then these parts are
preferably the mixer walls and/or the mixer tools. The
former may be brought to the desired temperature by
means of a heatable jacket, the latter by means of
15 incorporated heating elements.
In the case where granules comprising surfactants are
prepared in fully or partly heated mixers, further
preference is given to the use of nonaqueous
20 granulating aids, especially nonionic surfactants,
having a melting point in the range from 20 to 50°C. By
means of the preferred granulation process described,
it is possible to raise the bulk density of the
surfactant granules, accompanied by a marked reduction
25 in instances of unwanted caking on the mixer walls. The
use of surfactant granules thus produced in tabletable
premixes leads to laundry detergent and cleaning
product tablets distinguished by a further-reduced
disintegration time relative to mixtures comprising
30 conventionally prepared granules.
In step b) of the last-depicted process, the surfactant
granules are blended with further ingredients of
laundry detergents or cleaning products, it being
35 possible to use all of these ingredients described
CA 02316591 2000-08-23
66
earlier on above. In the final step, the premix is
compressed to give tablets or tablet regions, e.g.,
layers of multilayer tablets.
The use of oxidized derivatives of starch and/or
dextrins with the aim of improving the physical
properties of laundry detergent or cleaning product
tablets is not disclosed in the prior art . The present
invention therefore additionally provides for the use
of oxidized derivatives of starch and/or of dextrins to
improve the physical properties of laundry detergent or
cleaning product tablets.
In addition to the improvement in abrasion stability
and the increase in resistance to edge fracture, in
particular, the hardness is increased and the
disintegration times are minimized. The use of oxidized
derivatives of starch and/or of dextrins to increase
the hardness and reduce the disintegration time of
laundry detergent and cleaning product tablets is
therefore also provided by the present invention.
The abovementioned advantageous properties may also be
obtained by means of surfactant granules which comprise
oxidized derivatives of starch and/or dextrins. In a
further aspect, therefore, the present invention
provides for the use of surfactant granules which
comprise oxidized derivatives of starch and/or dextrins
for improving the physical properties of laundry
detergent or cleaning product tablets, especially for
increasing the hardness and reducing the disintegration
time.
CA 02316591 2000-08-23
67
Examples
Spray drying was used to prepare a surfactant-
comprising tower powder which was used as a basis for
granules comprising surfactant. The tower powder was
granulated with further components (zeolite, NaOH,
anionic surfactant acid, nonionic surfactant) in a
130 liter Lodige plowshare mixer. The surfactant
granules E of the invention were granulated using a 40~
strength solution of oxidized starch in water; at the
same point in the granulation of the comparative
granules, V, only water was added. The amounts of the
solids and liquids used, and the sequence of the
addition to the mixer, are indicated in Table 2.
Following granulation, the granules were dried in a
Glatt fluidized-bed apparatus at an air entry
temperature of 60°C for a period of 30 minutes. After
drying, fine fractions < 0.6 mm and coarse fractions
> 1.6 mm were removed by sieving.
The surfactant granules E and V, respectively, were
then processed together with further components to give
a compressible premix, tableting taking place in a
Korsch eccentric press (tablet diameter: 44 mm, height:
22 mm, weight: 37.5 g). The compressive pressure was
adjusted to give in each case three series of tablets
(E1, E2, E3 and V1, V2, V3) differing in their
hardness. The composition of the spray-dried tower
powder is shown in Table 1, the composition of the
premixes for compression (and thus of the tablets) in
Table 3.
CA 02316591 2000-08-23
68
Table 1: Composition of the spray-dried tower powder
[% by wefightJ
C9_13 alkylbenzenesulfonate 22.8
Soap 1.3
C~z-~e tallow alcohol containing 5 1.3
EO
Sodium sulfate 4.0
Zeolite A 48.0
Acrylic acid-malefic acid copolymer 8.0
Na hydroxyethane-l,l-diphosphonate 1.0
NaOH, anhydrous active substance 0.5
Water, salts remainder
Table 2: Granulation mixture
Inventive Comparative
Example Example
E V
Amount Sequ- Amount Sequ-
in % ence in % ence
Tower powder (Table 1) 40.0 1 40.0 1
Wessalith~ P (zeolite 40.0 1 40.0 1
A)
NaOH, 50% strength in 2.0 2 2.0 2
water
C9-13 alkylbenzene- 8.0 3 8.0 3
sulfonic acid
Wz-~a fatty alcohol 5.0 3 5.0 3
containing 7 EO
Oxidized starch, 40% 5.0 4 - -
strength in water*
Water - - 5.0 4
* EMOX TSD from Emsland-Starke
CA 02316591 2000-08-23
69
Table 3: Composition of the premix [% by weight]:
E V
Surfactant granules E (Table 2) 60.8 -
Surfactant granules V (Table 2) - 60.8
Sodium percarbonate 17.8 17.8
TAED 7.3 7.3
Foam inhibitor 3.5 3.5
Polyacrylate 1.1 1.1
Enzymes 2.5 2.5
Perfume 0.5 0.5
Wessalith~ P (zeolite A) 1.0 1.0
Disintegration aid (cellulose) 5.5 5.5
The hardness of the tablets was measured after two days
of storage by deformation of the tablet until it
fractured, with the force acting on the side faces of
the tablet and the maximum force withstood by the
tablet being measured.
To determine the tablet disintegration, the tablet was
placed in a glass beaker with water (600 ml of water,
temperature 30°C), and the time taken for the tablet to
undergo complete disintegration was measured. The
experimental data are shown in Table 4.
Table 4: Laundry detergent tablets [physical data]
Tablet El Vl E2 V2 E3 V3
Hardness 42 N 39 N 53 N 51 N 58 N 59 N
Disintegra- 15 sec 21 sec 28 sec 37 sec 47 sec >60 sec
tion
The use of oxidized starch in accordance with the
invention reduces the disintegration time of the
CA 02316591 2000-08-23
laundry detergent tablets, having a markedly positive
effect especially in the case of relatively high tablet
hardnesses.
5 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
10 the claims and not to limit them unnecessarily.
