Note: Descriptions are shown in the official language in which they were submitted.
CA 02313227 2000-07-28
MULTIPHASE DETERGENT TABLETS
Field of the Invention
This invention relates generally to multiphase detergent tablets.
More particularly, the invention relates to multiphase detergent tablets
which are used for washing laundry in a domestic washing machine and
which are referred to in short as detergent tablets.
Background of the Invention
By virtue of the ease with which they can be dosed and other
advantages in regard to packaging, transportation and storage, tablets
afford a number of advantages which make it appear desirable also to
produce detergents in tablet form. A broad prior art exists on the subject of
detergent tablets, being concerned in particular with overcoming a major
problem of tablets, namely the dichotomy between the hardness of tablets
on the one hand and their disintegration rate on the other hand. Adequate
hardness is es:>ential for the packaging, storage, transportation and
handling of tablets while their disintegration properties critically influence
the washing process and sufficiently rapid disintegration is absolutely
essential for the formation of a suitably concentrated wash liquor.
The problem of finding a technically reasonable compromise
between hardne:cs and disintegration is further complicated in the case of
multiphase table~a. It can be of advantage with the washing process in
mind to separate certain detergent ingredients from one another. However,
such separation does lead to differences in the physical property profiles of
the various phases in the tablet. Thus, in the extreme case, inter-phase
adhesion can diminish to such an extent that multiphase tablets can no
longer be produced. The effect of an excessive difference in hardness
between different: phases would be that certain phases would be damaged
to a greater extent during packaging, transportation and handling than
other phases. In addition, excessive differences between the disintegration
and dissolving rates of individual phases would also be undesirable
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2
because otherwise active ingredients from the more slowly disintegrating or
dissolving phase would riot be available to the washing process. Moreover,
it may be desirable for the individual phases of the tablets to have different
surfactant contents in order to increase the freedom of choice in selecting
particular formul~~tions.
Accordingly, it is crucially important in the case of multiphase
detergent tablets for all the phases to adhere to one another and to show
adequate and comparable hardness and a sufficiently rapid and identical
disintegration and dissolving profile, even when the individual phases differ
significantly in their surfactant content. Proposed solutions to these
problems are de:ccribed in only a few prior-art publications.
Detergent tablets in which individual ingredients are separated from
others are also described in EP-A-0 481 793 (Unilever). The detergent
tablets disclosed in this document contain sodium percarbonate which is
separated from ;III other components that could affect its stability. The
document in que;~tion does not mention hardness and/or disintegration as a
function of phase composition.
EP-A-0 4E~6 485 (Unilever) describes detergent tablets produced by
tabletting two types of surfactant-containing granules. One type contains
the total quantity of anionic surfactants while the second type is preferably
free from anionic surfactants. This document also does not mention
hardness and/or ~~isintegration as a function of phase composition.
Summary of the Invention
Now, the problem addressed by the present invention was to provide
multiphase detergent tablets which would overcome the disadvantages
mentioned above. More particularly, the invention sought to provide
multiphase deter~~ent tablets which would have high hardness values and
high disintegration and dissolving rates in all phases, irrespective of the
degree of difference in surfactant content between the individual phases.
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3
It has no~N been found that multiphase detergent tablets with an
excellent property profile can be produced provided that - where the
surfactant contents in the individual phases vary - larger quantities of
adsorbing substances are added to the phases) with the higher surfactant
content than to i:he phases) with the lower surfactant content during the
aftertreatment of the premix to be tabletted.
Accordingly, the present invention relates to two or more phase
detergent tablets of compacted particulate detergent comprising
surfactant(s), builders) and optionally other detergent ingredients,
characterized in that the surfactant content of the individual phases of the
tablets varies by more than 3% by weight, based on the weight of the
individual phase, a component A with an oil adsorption capacity of at least
g/100 g and ~~n average particle size below 50~,m, based on the weight
of the phase, bE~ing present in larger quantities in the phases) with the
15 higher surfactant: content than in the phases) with the lower surfactant
content.
Detailed Descri~~tion of the Invention
In the conl:ext of the present invention, the variation of the surfactant
content by more than 3°ro by weight, based on the weight of the
individual
20 phases, means i:hat the absolute values of the surfactant content in the
phases vary by more than 3% by weight. If, therefore, one phase contains
20% by weight of surfactant(s), the surfactant content of the other phases)
must be selected so that the range of variation about the value 20 is more
than 3% by weight. In other words, the percentage figure for the surfactant
content of the phase with the lower surfactant content is subtracted from
that of the phase with the higher surfactant content, the result from phase
to phase having to be > 3. In a four-phase tablet, this would mean that -
for a surfactant content of 12% by weight in the phase with the lowest
surfactant content - the next phases would have surfactant contents of, for
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4
example, 15.1 % by weight, 18.2% by weight and 21.3% by weight.
According to the invention, one phase may also be completely free
from surfactants (corresponding to a surfactant content of 0% by weight,
based on that phase). In that case, the next phase must have a surfiactant
content of more than 3°ro by weight to satisfy the criteria according
to the
invention.
With incrE;asing surfactant content, the individual phases of the
detergent tablets according to the invention contain increasing amounts of
a component A ~~rith an oil adsorption capacity of at least 20g/100g, with
the proviso that the phase with the higher surfactant content - based on the
overall composition of the phase - has a higher percentage content of that
component. In a preferred embodiment of the invention, the content of the
component A in the phases) of higher surfactant content is higher by at
least 0.3% by weight, preferably by at least 0.5% by weight and more
preferably by at least 1 °~o by weight, based on the weight of the
individual
phase, than in the phases) with the lower surfactant content. On the basis
of the above-mentioned example of a four-phase tablet, the facts may be
illustrated as follows: if, besides the 12% by weight of surfactant
mentioned, the phase with the lowest surfactant content contains 1.5% by
weight of the component with an oil adsorption capacity of 20g/100g, the
second phase would contain at least 1.8% by weight (preferably 2.0% by
weight and morE: preferably 2.5% by weight) of that component. The
content of the component with an oil adsorption capacity of 20g/100g in the
third phase is dnterminE~d by the real content of that component in the
second phase - here, too, the difference is preferably at least 0.3% by
weight, more prE;ferably at least 0.5% by weight and most preferably at
least 1.0% by weight. The same applies to the fourth phase.
Besides the absolute content of surfactants) and the components)
with an oil adsorption capacity of more than 20g/100g in the individual
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phases, based on the composition of the individual phase, the ratio of the
quantities in th~~ individual phases to one another is also variable.
According to the invention, preferred detergent tablets are those in which
the quantity ratio of the component A between the individual phases is
greater than the quantity ratio of the surfactants between those phases.
If the above-mentioned example is again used for illustration, the
ratio of the surfia~~tant contents between phase 2 and phase 1 is 15.1:12.0
- 1.26:1. Now. the second phase compared with the first preferably
contains so much of the component A that the ratio of this component in
5 the two phases is greater than 1.26. If, therefore, phase 1 contains, for
example, 1.5% by weight of the component A, phase 2 should contain
more than 1.26 times that quantity, i.e. at least 1.9% by weight of the
component in qraestion. Now, depending on how large the content of
surfactant and cil adsorption component in the individual phase is, the
contents of these ingredients in the other phases can be varied so that they
satisfy the criteria mentioned. In the case of a phase which is free from oil
adsorption component or free from surfactants, the formation of ratios is
mathematically pointless so that absolute values in the sense of the
preferred embodiments of the invention described in the foregoing are used
in such a case.
According to the invention, the oil adsorption components present in
the individual surfactant-containing phases of the tablet have an oil
adsorption capacity of at least 20g/100g. However, oil adsorption
components with a higher oil adsorption capacity are preferably used.
Preferred deter~;ent tablets are characterized in that the component
present in them has an oil adsorption capacity of at least 50g/100g,
preferably of at Ic;ast 80g/100g, more preferably of at least 120g/100g and
most preferably of at least 140g/100g.
The oil aclsorption capacity is a physical property of a substance
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6
which can be measured by standardized methods. For example, British
Standards BS 1 ~~95 and BS 3483: Part B7: 1092, which both refer to ISO
787/5, are avail;~ble. In these test methods, a weighed sample of the
particular substance is applied to a dish and refined linseed oil (density:
0.93 gcm-3) is added dropwise from a burette. After each addition, the
powder is intensively mi:Ked with the oil using a spatula, the addition of oil
being continued until a paste of flexible consistency is obtained. This paste
should flow without crumbling. Now, the oil adsorption capacity is the
quantity of oil added dropwise, based on 100 g of adsorbent, and is
expressed in ml/'100 g or g/100 g, conversions via the density of the linseed
oil readily being possible.
The oil adsorption component preferably has a small average
particle size bec<~use the active surface increases with decreasing particle
size. Preferred detergent tablets contain a component with an oil
adsorption capacity of at least 20g/100g which has an average particle size
below 20 pm and more preferably below 10 Nm.
The oil adsorption component may be selected from any of a
number of substances. There are large numbers of both inorganic and
organic substances which have a sufficiently high oil adsorption capacity,
including for example fine-particle materials obtained by precipitation.
Suitable substances such as these are, for example, silicates,
alumosilicates, calcium silicates, magnesium silicates and calcium
carbonate. However, kieselguhr (diatomaceous earth) and fine-particle
cellulose fibers or derivatives thereof may also be used in accordance with
the invention. Preferred detergent tablets are characterized in that the
component A present in them is selected from silicates and/or
alumosilicates, more particularly from the group of silicas and/or zeolites.
For example, fine-particle zeolites and pyrogenic silicas (Aerosil~)
or precipitated silicas may be used.
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7
According to the invention, the individual phases of the tablets may
assume various 'three-dimensional forms. The most simple embodiment is
a two-layer or multilayer- tablet, each layer of the tablet representing one
phase. However, it is also possible in accordance with the invention to
produce multiphase tablets in which individual phases assume the form of
inclusions in (an)other phase(s). Besides so-called "ring/core" tablets,
jacket tablets or combinations of the embodiments mentioned are also
possible. Examples of multiphase tablets can be found in the drawings of
EP-A-0 055 100 (,Jeyes) which describes toilet cleaning blocks.
Technically the rnost common form of multiphase tablets are two-layer or
multilayer tablets. According to the invention, therefore, the phases of the
tablet are preferably in the form of layers.
According to the invention, it is crucial that the surfactant content of
the individual ph<~ses of the tablet vary by more than 3% by weight, based
on the weight of 'the individual phase, and that the phases) with the higher
surfactant content contain more oil adsorption component than the phases
with the lower suifiactant content. Determination of the surfactant content is
based on the sum of the surfiactants present in the particular phase,
irrespective of the type of surfactant involved. If one phase contains
anionic and nonionic surfactants, for example, the total surfactant content
of the phase i > the sum of the quantities of anionic and nonionic
surfactants.
The surfactants may be incorporated in the individual phases of the
tablet in pure form. This is readily possible, for example, in the case of
soaps or other readily processable surfactants. With many surfactants,
however, it is advisable to incorporate surfactant compounds rather than
the pure surfaci:ants. These compounds - which should have high
surfactant contents according to the particular application - may be
produced by conventional processes, such as spray drying, granulation or
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compounding. ~~ combination of several batches of surfactant granules or
a combination of surfactant granules with pure surfactants is of course also
possible.
According to the invention, the surfactants) are introduced into the
phases of the tak~lets through surfactant-containing granules.
In other embodiments of the present invention, different surfactant
granules may be used for each phase. However, each phase may also
derive its surfactant content from the same granules which are therefore
present in all phases of the tablet. Another preferred embodiment of the
invention is char~~cterized in that the same surfactant granules are used in
all phases of the tablets.
Now, the most simple possible embodiment of the present invention
is a two-phase tablet in which the phases are present as layers and in
which the same surfactant granules are used in different quantities in the
two layers. These tablets of two layers containing the same surfactant
granules can rea~~ily be produced in conventional tablet presses.
Anionic, n~~nionic, cationic and/or amphoteric surfactants or mixtures
thereof may be used in the detergent tablets according to the invention.
Mixtures of anionic and nonionic surfactants are preferred from the
applicational point of view. The tablets have a total surfactant content of 5
to 60% by weight, based on tablet weight, surfactant contents of more than
15% by weight bE~ing preferred.
Suitable anionic surfactants are, for example, those of the sulfonate
and sulfate type. Suitable surfactants of the sulfonate type are preferably
C9_~3 alkyl benzenesulfonates, olefin sulfonates, i.e. mixtures of alkene and
hydroxyalkane sulfonates, and the disulfonates obtained, for example, from
C~2_~$ monoolefins with an internal or terminal double bond by sulfonation
with gaseous suli-ur triaxide and subsequent alkaline or acidic hydrolysis of
the sulfonation products. Other suitable surfactants of the sulfonate type
CA 02313227 2000-07-28
9
are the alkane :~ulfonates obtained from C~2_~$ alkanes, for example by
sulfochlorination or sulfoxidation and subsequent hydrolysis or neutral-
ization. The estE:rs of a-~sulfofatty acids (ester sulfonates), for example
the
a-sulfonated mei:hyl esters of hydrogenated coconut oil, palm kernel oil or
tallow fatty acids; are also suitable.
Other suitable anionic surfactants are sulfonated fatty acid glycerol
esters. Fatty acid glycerol esters in the context of the present invention are
the monoesters, diesters and triesters and mixtures thereof which are
obtained where production is carried out by esterification of a monoglycerol
with 1 to 3 moles of fatty acid or in the transesterification of triglycerides
with 0.3 to 2 moles of glycerol. Preferred sulfonated fatty acid glycerol
esters are the sulfonation products of saturated fatty acids containing 6 to
22 carbon atoms, for example 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, in
particular, the sodium salts of the sulfuric acid semiesters of C~2_~$ fatty
alcohols, for example coconut alcohol, tallow alcohol, lauryl, myristyl, cetyl
or stearyl alcohol, or Coo-2o oxoalcohols and the corresponding semiesters
of secondary alcohols with the same chain length. Other preferred
alk(en)yl sulfates are those with the chain length mentioned which contain
a synthetic, line<~r alkyl chain based on a petrochemical and which are
similar in their degradation behavior to the corresponding compounds
based on oleochemical raw materials. C~2_~6 alkyl sulfates, C~2_~5 alkyl
sulfates and Cia..~5 alkyl sulfates are preferred from the point of view of
washing technology. (Jther suitable anionic surfactants are 2,3-alkyl
sulfates which may be produced, for example, in accordance with US
3,234,258 or U~~ 5,075,041 and which are commercially obtainable as
products of the Shell Oil Company under the name of DAN~.
The sulfuric acid monoesters of linear or branched C~_2, alcohols
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ethoxylated with 1 to 6 moles of ethylene oxide, such as 2-methyl-branched
C9_~~ alcohols containing on average 3.5 moles of ethylene oxide (EO) or
C~2_~g fatty alcohols containing 1 to 4 EO, are also suitable. In view of
their
high foaming capacity, they are only used in relatively small quantities, for
5 example in quani:ities of 1 to 5% by weight, in dishwashing detergents.
Other suit;~ble anionic surfactants are the salts of alkyl sulfosuccinic
acid which are also known as sulfosuccinates or as sulfosuccinic acid
esters and which represent monoesters and/or diesters of sulfosuccinic
acid with alcohols, preferably fatty alcohols and, more particularly,
10 ethoxylated fatty alcohols. Preferred sulfosuccinates contain C$_~$ fatty
alcohol residues or mixtures thereof. Particularly preferred sulfosuccinates
contain a fatty ;~Icohol residue derived from ethoxylated fatty alcohols
which, consider~:d in isolation, represent nonionic surfactants (for a
description, see below). Of these sulfosuccinates, those of which the fatty
alcohol residues are derived from narrow-range ethoxylated fatty alcohols
are particularly preferred. Alk(en)yl succinic acid preferably containing 8 to
18 carbon atoms in the alk(en)yl chain or salts thereof may also be used.
Other suitable anionic surfactants are, in particular, soaps. Suitable
soaps are satur;~ted fatty acid soaps, such as the salts of lauric acid,
myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and
behenic acid, arid soap mixtures derived in particular from natural fatty
acids, for example coconut oil, palm kernel oil or tallow fatty acids.
The anionic surfactants, including the soaps, may be present in the
form of their sodium, potassium or ammonium salts and as soluble salts of
organic bases, such as mono-, di- or triethanolamine. The anionic
surfactants are preferably present in the form of their sodium or potassium
salts and, more preferably, in the form of their sodium salts.
Preferred nonionic surfactants are alkoxylated, advantageously
ethoxylated, morE~ especially primary alcohols preferably containing 8 to 18
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11
carbon atoms arid, on average, 1 to 12 moles of ethylene oxide (EO) per
mole of alcohol, in which the alcohol component may be linear or,
preferably, methyl-branched in the 2-position or may contain linear and
methyl-branched residues in the form of the mixtures typically present in
oxoalcohol residues. However, alcohol ethoxylates containing linear
residues of alcahols of native origin with 12 to 18 carbon atoms, for
example coconut oil, palm oil, tallow fatty or oleyl alcohol, and on average 2
to 8 EO per mole of alcohol are particularly preferred. Preferred
ethoxylated alcohols include, for example, C~2_~4 alcohols containing 3 EO
or 4 EO, C9_~~ al~;,ohol containing 7 EO, C~3_~5 alcohols containing 3 EO, 5
EO, 7 EO or 8 f=O, C~2_~$ alcohols containing 3 EO, 5 EO or 7 EO and
mixtures thereof, such as mixtures of C~2_~4 alcohol containing 3 EO and
C~2_~$ alcohol containing 5 EO. The degrees of ethoxylation mentioned
represent statistical mean values which, for a special product, can be a
whole number or' a broken number. Preferred alcohol ethoxylates have a
narrow homolog distribution (narrow range ethoxylates, NRE). In addition
to these nonionic surfactants, fatty alcohols containing more than 12 EO
may also be used, examples including tallow fatty alcohol containing 14
EO, 25 EO, 30 E~~ or 40 EO.
Another class of nonionic surfactants which may advantageously be
used are alkyl glycosides corresponding to the general formula RO(G)X
where R is a primary linear or methyl-branched, more particularly 2-methyl-
branched, aliphatic radical containing 8 to 22 and preferably 12 to 18
carbon atoms arid G stands for a glycose unit containing 5 or 6 carbon
atoms, preferably glucose. The degree of oligomerization x, which
indicates the distribution of monoglycosides and oligoglycosides, is a
number of 1 to 10, preferred values for x being 1.2 to 1.4.
Another class of preferred nonionic surfiactants which may be used
either as sole nonionic surfactant or in combination with other nonionic
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12
surfactants are alkoxylated, preferably ethoxylated or ethoxylated and
propoxylated, falay acid alkyl esters preferably containing 1 to 4 carbon
atoms in the alkyl chain, more especially the fatty acid methyl esters which
are described, fcrr example, in Japanese patent application JP 58/217598
or which are prei~erably produced by the process described in International
patent application WO-A-90/13533.
Nonionic surfactants of the amine oxide type, for example N-
cocoalkyl-N,N-dirnethylamine oxide and N-tallowalkyl-N,N-dihydroxyethyl-
amine oxide, anti the fatty acid alkanolamide type are also suitable. The
quantity in which these nonionic surfactants are used is preferably no more
than the quantit~~ in which the ethoxylated fatty alcohols are used and,
more preferably, no morE; than half that quantity.
Other suitable surfactants are polyhydroxyfatty acid amides
corresponding to formula (I):
R'
R-CO-N-[Z] ( I )
in which RCO is an aliphatic acyl group containing 6 to 22 carbon atoms,
R' is hydrogen, an alkyl or hydroxyalkyl group containing 1 to 4 carbon
atoms and [Z] is a linear or branched polyhydroxyalkyl group containing 3
to 10 carbon atorns and ;3 to 10 hydroxyl groups. The polyhydroxyfatty acid
amides are known substances which may normally be obtained 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 polyhydroxyfatty acid amides also includes compounds
corresponding to formula (II):
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13
R'-O-R2
R-CO-N-[Z] ( I I )
in which R is a linear ar branched alkyl or alkenyl group containing 7 to 12
carbon atoms, R~~ is a linear, branched or cyclic alkyl group or an aryl group
containing 2 to 8 carbon atoms and R2 is a linear, branched or cyclic alkyl
group or an aryl croup or an oxyalkyl group containing 1 to 8 carbon atoms,
C~_4 alkyl or phenyl groups being preferred, and [Z] is a linear polyhydroxy-
alkyl group, of which the alkyl chain is substituted by at least two hydroxyl
groups, or alkoxvlated, preferably ethoxylated or propoxylated, derivatives
of that group.
[Z] is prefE~rably obtained by reductive amination of a reduced sugar,
for example glucose, fructose, maltose, lactose, galactose, mannose or
xylose. The N-alkoxy- or N-aryloxy-substituted compounds may then be
converted into the required polyhydroxyfatty acid amides by reaction with
fatty acid methyl esters in the presence of an alkoxide as catalyst, for
example in accordance with the teaching of International patent application
WO-A-95/07331.
According to the invention preferred detergent tablets contain
anionic and nonionic surfactant(s). Performance-related advantages can
arise out of certain quantity ratios in which the individual classes of
surfactant are used.
For example, particularly preferred detergent tablets are those 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 more preferably
between 5:1 and 1:2.
Certain performance-related advantages can be obtained if certain
classes of surfactant arc: not present in certain phases of the detergent
tablets or in any of the phases. In another important embodiment of the
CA 02313227 2000-07-28
14
present invention, therefore, at least one phase of the tablets is free from
nonionic surfactants.
Conversely, however, a positive effect can also be obtained if
individual phases or thE: tablet as a whole, i.e. all the phases, contain
certain surfactants. The introduction of the alkyl polyglycosides described
above has proved to be .advantageous so that detergent tablets in which at
least one phase contains alkyl polyglycosides are preferred.
As with the nonionic surfactants, the omission of anionic surfactants
from individual phases or from all the phases can also result in detergent
tablets which arE: better suited to certain applications. According to the
invention, therefore, detf~rgent tablets in which at least one phase is free
from anionic surf,~ctants are also possible.
Besides the detersive substances, builders are the most important
ingredients of detergents. The detergent tablets according to the invention
may contain any of the builders typically used in detergents, i.e. in
particular zeolitEa, silicates, carbonates, organic co-builders and -
providing there are no ecological objects to their use - the phosphates.
Suitable crystalline layer-form sodium silicates correspond to the
general formula PJaMSiXO2x+~y H20, where M is sodium or hydrogen, x is a
number of 1.9 to 4 and y is a number of 0 to 20, preferred values for x
being 2, 3 or 4. Crystalline layer silicates such as these are described, for
example, in European patent application EP-A-0 164 514. Preferred
crystalline layer silicates corresponding to the above formula are those in
which M is sodium and x assumes the value 2 or 3. Both ~3- and 8-sodium
disilicates Na2Si;>05y H20 are particularly preferred, ~3-sodium disilicate
being obtainable, for example, by the process described in International
patent application WO-A- 91!08171.
Other usE;ful builders are amorphous sodium silicates with a
modulus (Na20:~~i02 ratio) of 1:2 to 1:3.3, preferably 1:2 to 1:2.8 and more
CA 02313227 2000-07-28
preferably 1:2 to 1:2.6 which dissolve with delay and exhibit multiple wash
cycle properties. The delay in dissolution in relation to conventional
amorphous sodium silicates can have been obtained in various ways, for
example by surface treal:ment, compounding, compacting or by overdrying.
5 In the context of the invention, the term "amorphous" is also understood to
encompass "X-r,ay amorphous". In other words, the silicates do not
produce any of the sharp X-ray reflexes typical of crystalline substances in
X-ray diffraction experiments, but at best one or more maxima of the
scattered X-radiation which have a width of several degrees of the
10 diffraction angle. However, particularly good builder properties may even
be achieved whE:re the silicate particles produce crooked or even sharp
diffraction maxima in Electron diffraction experiments. This may be
interpreted to mean that the products have microcrystalline regions
between 10 and a few hundred nm in size, values of up to at most 50 nm
15 and, more particularly, up to at most 20 nm being preferred. So-called X
ray amorphous ~~ilicates such as these, which also dissolve with delay in
relation to conventional waterglasses, are described for example in
German patent application DE-A-44 00 024. Compacted amorphous
silicates, compounded amorphous silicates and overdried X-ray-amorphous
silicates are parti~~ularly preferred.
The finely crystalline, synthetic zeolite containing bound water used
in accordance with the invention is preferably zeolite A and/or zeolite P.
Zeolite MAP~ (Crosfield) is a particularly preferred P-type zeolite.
However, zeolite X and mixtures of A, X and/or P are also suitable.
According to thE; invention, it is also possible to use, for example, a
commercially obtainable co-crystallizate of zeolite X and zeolite A (ca. 80%
by weight zeolite X) which is marketed by CONDEA Augusta S.p.A. under
the name of VE=GOBOND AX~ and which may be described by the
following formula
CA 02313227 2000-07-28
16
nNa20 ~ (1-n)K2C) ~ AI2C)3 ~ (2 - 2.5)Si02 ~ (3.5 - 5.5) H20.
The zeolite may be used both as a builder in a granular compound and
also to "powder" the entire mixture to be tabletted, both methods normally
being used to incorporate the zeolite in the premix. Suitable zeolites have
a mean particle size of less than 10 ~m (volume distribution, as measured
by the Coulter Counter Method) and contain preferably 18 to 22% by
weight and more preferably 20 to 22% by weight of bound water.
The generally known phosphates may of course also be used as
builders providing their use should not be avoided on ecological grounds.
The sodium salsa of the orthophosphates, the pyrophosphates and, in
particular, the tripolyphosphates are particularly suitable.
Useful organic builders are, for example, the polycarboxylic acids
usable, for example, in the form of their sodium salts, such as citric acid,
adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids, amino
carboxylic acids, nitrilotriacetic acid (NTA), providing its use is not
ecologically uns~~fe, and mixtures thereof. Preferred salts are the salts of
the polycarboxylic acids, such as citric acid, adipic acid, succinic acid,
glutaric acid, tart<~ric acid, sugar acids and mixtures thereof.
In order to facilitate the disintegration of heavily compacted tablets,
disintegration aids, so-called tablet disintegrators, may be incorporated in
them to shorten their clisintegration times. According to Rompp (9th
Edition, Vol. 6, page 4440) and Voigt "Lehrbuch der pharmazeutischen
Technologie" (6th Edition, 1987, pages 182-184), tablet disintegrators or
disintegration accelerators are auxiliaries which provide for the rapid
disintegration of tablets in water or gastric juices and the release of the
pharmaceuticals in an absorbable form.
These substances, which are also known as "disintegrators" by
CA 02313227 2000-07-28
17
virtue of their efi'ect, are capable of undergoing an increase in volume on
contact with water so that, on the one hand, their own volume is increased
(swelling) and, on the other hand, a pressure can be generated through the
release of gases which causes the tablet to disintegrate into relatively small
particles. Well-known disintegrators are, for example, carbonate/citric acid
systems, although other organic acids may also be used. Swelling dis-
integration aids are, for example, synthetic polymers, such as polyvinyl
pyrrolidone (PVF'), or natural polymers and modified natural substances,
such as cellulose and starch and derivatives thereof, alginates or casein
derivatives.
Preferred detergent tablets contain 0.5 to 10% by weight, preferably
3 to 7% by weight and more preferably 4 to 6% by weight of one or more
disintegration aids, based on the weight of the tablet.
According to the invention, preferred disintegrators are cellulose
based disintegrators, so that preferred detergent tablets contain a
cellulose-based disintegrator in quantities of 0.5 to 10% by weight,
preferably 3 to 7~% by weight and more preferably 4 to 6% by weight. Pure
cellulose has the formal empirical composition (C6H~o05)~ and, formally, is
a ~3-1,4-polyacetal of cellobiose which, in turn, is made up of two molecules
of glucose. Suitable celluloses consist of ca. 500 to 5000 glucose units
and, accordingly, have average molecular weights of 50,000 to 500,000.
According to the invention, cellulose derivatives obtainable from cellulose
by polymer-analog reactions may also be used as cellulose-based
disintegrators. These chemically modified celluloses include, for example,
products of esterification or etherification reactions in which hydroxy
hydrogen atoms have been substituted. However, celluloses in which the
hydroxy groups have been replaced by functional groups that are not
attached by an oxygen atom may also be used as cellulose derivatives.
The group of cellulose derivatives includes, for example, alkali metal
CA 02313227 2000-07-28
18
celluloses, carboxymethyl cellulose (CMC), cellulose esters and ethers and
aminocelluloses. The cellulose derivatives mentioned are preferably not
used on their own, but rather in the form of a mixture with cellulose as
cellulose-based disintegrators. The content of cellulose derivatives in
mixtures such as theses is preferably below 50% by weight and more
preferably belo~nr 20% by weight, based on the cellulose-based
disintegrator. In one particularly preferred embodiment, pure cellulose free
from cellulose derivatives is used as the cellulose-based disintegrator.
The cellulose used as disintegration aid is preferably not used in
fine-particle form, but is converted into a coarser form, for example by
granulation or compacting, before it is added to and mixed with the
premixes to be tabletted. Detergent tablets which contain granular or
optionally co-granulated disintegrators are described in German patent
applications DE '197 09 991 (Stefan Herzog) and DE 197 10 254 (Henkel)
and in Internatienal patent application WO 98/40463 (Henkel). Further
particulars of thf~ production of granulated, compacted or co-granulated
cellulose disintegrators can also be found in these patent applications. The
particle sizes of :;uch disintegration aids is mostly above 200 pm, at least
90% by weight of the particles being between 300 and 1600 Nm in size
and, more particularly, between 400 and 1200 pm in size. According to the
invention, the above-described relatively coarse-particle cellulose-based
disintegrators described in detail in the cited patent applications are
preferably used as disintegration aids and are commercially obtainable, for
example under the name of Arbocel~ TF-30-HG from Rettenmaier.
Microcrystalline cellulose may be used as another cellulose-based
disintegration aid or as part of such a component. This microcrystalline
cellulose is obtained by partial hydrolysis of the celluloses under conditions
which only attack and completely dissolve the amorphous regions (ca. 30%
of the total cellulose mass) of the celluloses, but leave the crystalline
CA 02313227 2000-07-28
19
regions (ca. 7G%) undamaged. Subsequent de-aggregation of the
microfine celluloses formed by hydrolysis provides the microcrystalline
celluloses which have primary particle sizes of ca. 5 pm and which can be
compacted, for example, to granules with a mean particle size of 200 pm.
According to the present invention, therefore, detergent tablets
additionally containing a disintegration aid, preferably a cellulose-based
disintegration aici, preferably in granulated, cogranulated or compacted
form, in quantities of 0.5 to 10% by weight, preferably 3 to 7% by weight
and more preferably 4 to 6% by weight, based on the weight of the tablet,
are particularly preferred.
Detergent tablets are produced by the application of pressure to a
mixture to be tabletted which is accommodated in the cavity of a press. In
the most simple method of tablet production - hereinafter referred to simply
as tabletting - the mixture to be tabletted is compressed directly, i.e.
without preliminary granulation. The advantages of this so-called direct
tabletting are its simple and inexpensive application because no other
process steps and hence no other items of equipment are involved.
However, these advantages are offset by disadvantages. Thus, a powder
mixture which is to be directly tabletted must possess adequate plastic
deformability and good flow properties and must not show any tendency to
separate during :storage, transportation and filling of the die.
Unfortunately,
these three requirements are very difficult to satisfy with many mixtures so
that direct tabletting is often not applied, particularly in the production of
detergent tablets. Accordingly, the normal method of producing detergent
tablets starts out from powder-form components ("primary particles") which
are agglomerated or granulated by suitable methods to secondary particles
with larger particle diameters. These granules or mixtures of different
granules are then mixed with individual powder-form additives and the
resulting mixtures are tabletted. Depending on the composition of the
CA 02313227 2000-07-28
phases of the multiphase detergent tablets, the die is filled in steps with
different premixes. In the production of multilayer tablets, the application
of
light pressure between the fillings with premixes can have advantages for
the next step. In the production of ring/core tablets or jacket tablets,
5 precompression and shaping/forming such as this is even almost
indispensable.
According to the invention, preferred detergent tablets are obtained
by tabletting particulate premixes of at least one batch of surfactant-
containing granules and at least one subsequently added powder-form
component. The surfactant-containing granules may be produced by
conventional granulation processes, such as mixer and pan granulation,
fluidized bed granulation, extrusion, pelleting or compacting. It is of
advantage so far as the subsequent detergent tablets are concerned if the
premixes to be t<~bletted have a bulk density approaching that of standard
compact detergents. In ~one particularly preferred embodiment, the premix
to be tabletted has a bulk density of at least 500 g/I, preferably of at least
600 g/I and more preferably above 700 g/I. Another advantage can arise
out of a relatively narrow particle size distribution of the surfactant
granules
used. According to the invention, preferred detergent tablets are those in
which the granules have particle sizes of 10 to 4,000 pm, preferably
between 100 anti 2,000 pm and more preferably between 600 and 1,400
Nm.
Accordingly, the present invention also relates to a process for the
production of two-phase or multiphase detergent tablets containing
surfactant(s), builders) and optionally other detergent ingredients by
10 tabletting known per se, characterized in that they are obtained by
tabletting of a particulate premix of at least one batch of surfactant-
containing granules and at least one subsequently incorporated powder-
form component, the surfactant content of the individual phases of the
CA 02313227 2000-07-28
21
tablets varying ~~y more than 3% by weight, based on the weight of the
individual phase and a component A with an oil adsorption capacity of at
least 20 g/100 g and an average particle size below 50 Nm, based on the
weight of the phase, being present in larger quantities in the phases) with
the higher surfactant content than in the phases) with the lower surfactant
content.
The foregoing observations on the variation of the surfactant content
and preferred values also apply to the process according to the invention.
Preferred processes are characterized in that the granules are
produced by conventional granulation processes, such as mixer and pan
granulation, fluidized bed granulation, extrusion, pelleting or compacting.
In particularly preferred processes, the granules have particle sizes of 10 to
4,000 Nm, preferably bEaween 100 and 2,000 pm and more preferably
between 600 and 1,400 dam.
The particle size distribution of the powder-form aftertreatment
components sub;~equently added can also be varied, detergent tablets
where the powder-form components) subsequently added contain the
component with an oil adsorption capacity of at least 20g/100g being
preferred.
Before thE~ particulate premix is compressed to form detergent
tablets, it may be "powdered" with fine-particle surface treatment materials.
This can be of advantage: to the quality and physical properties of both the
premix (storage, tabletting) and the final detergent tablets. Fine-particle
powdering materials have been known for some time in the art, zeolites,
silicates and other inorganic salts generally being used. However, the
premix is preferably "powdered" with fine-particle zeolite, zeolites of the
faujasite type being preferred. In the context of the present invention, the
expression "zeolite of the faujasite type" encompasses all three zeolites
which form the faujasite subgroup of zeolite structural group 4 (cf. Donald
CA 02313227 2000-07-28
22
W. Breck: "Zeolite Molecular Sieves" John Wiley & Sons, New
York/London/Syclney/Toronto, 1974, page 92). Besides zeolite X, there-
fore, zeolite Y and faujasite and mixtures of these compounds may also be
used, pure zeolite X being preferred.
Mixtures or co-crystallizates of faujasite zeolites with other zeolites,
which do not have to belong to zeolite structural group 4, may also be used
for powdering, in which case at least 50% by weight of the powdering
material advantageously consists of a faujasite zeolite.
These powdering materials may of course have an oil adsorption
capacity of more than 20g/100g, in which case they may replace or
augment the oil adsorption component. If the powdering materials are
used in addition to the oil adsorption components and have an oil
adsorption capacity of more than 20g/100g, they should of course be taken
into account in the calculation of the percentage content in the individual
phases.
According to the invention, preferred detergent tablets consist of a
particulate premix containing granular components and subsequently
incorporated povuder-form components, the, or one of the, fine-particle
components subsequently incorporated being a faujasite zeolite with
particle sizes below 100 pm, preferably below 10 Nm and more preferably
below 5 pm and making up at least 0.2% by weight, preferably at least
0.5% by weight and morE~ preferably more than 1 % by weight of the premix
to be compressed.
The fine-particle aftertreatment components with the particle sizes
mentioned above may be dry-mixed with the premix to be tabletted.
However, it is al~;o possible and preferred to "stick" them onto the surface
of the relatively coarse particles by addition of small quantities of liquid
components. These powdering techniques are widely described in the
prior art literature and are familiar to the expert. Liquid components
CA 02313227 2000-07-28
23
suitable as adhesion promoters for the powdering materials are, for
example, nonionic surfactants or aqueous solutions of surfactants or other
detergent ingredients. In one preferred embodiment of the invention,
perfume is used as the liquid component for promoting adhesion between
the fine-particle powdering material and the coarse particles.
Besides tree above mentioned ingredients (surfactants, builders and
disintegration aids), the detergent tablets according to the invention may
contain other typical detergent ingredients from the group of bleaching
agents, bleach activators, enzymes, perfumes, perfume carriers,
fluorescers, dyer, foam inhibitors, silicone oils, redeposition inhibitors,
optical brightenE~rs, discoloration inhibitors, dye transfer inhibitors and
corrosion inhibitors.
Among the compounds yielding H202 in water which serve as
bleaching agent~~, sodium perborate tetrahydrate and sodium perborate
monohydrate are particularly important. Other useful bleaching agents are,
for example, soclium percarbonate, peroxypyrophosphates, citrate perhy-
drates and H~~02-yielding peracidic salts or peracids, such as
perbenzoates, pE~roxophthalates, diperazelaic acid, phthaloiminoperacid or
diperdodecane dioic acid.
In order to obtain an improved bleaching effect where washing is
carried out at temperatures of 60°C or lower, bleach activators may be
incorporated in ~cne ar more phases. The bleach activators may be
compounds which form aliphatic peroxocarboxylic acids containing
preferably 1 to 10 carbon atoms and more preferably 2 to 4 carbon atoms
and/or optionally substituted perbenzoic acid under perhydrolysis
conditions. Subsaances bearing O- and/or N-acyl groups with the number
of carbon atoms mentioned and/or optionally substituted benzoyl groups
are suitable. F~referred bleach activators are polyacylated alkylene-
diamines, more particularly tetraacetyl ethylenediamine (TAED), acylated
CA 02313227 2000-07-28
24
triazine derivatives, more particularly 1,5-diacetyl-2,4-dioxohexahydro-
1,3,5-triazine (D~4DHT), acylated glycolurils, more particularly tetraacetyl
glycoluril (TAGU), N-acylimides, more particularly N-nonanoyl succinimide
(NOSI), acylate~l phenol sulfonates, more particularly n-nonanoyl or
isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides,
more particularly phthal'ic anhydride, acylated polyhydric alcohols, more
particularly triacetin, ethylene glycol diacetate and 2,5-diacetoxy-2,5-
dihydrofuran.
In addition to or instead of the conventional bleach activators
mentioned abovEa, so-called bleach catalysts may also be incorporated in
the tablets. Bleach catalysts are bleach-boosting transition metal salts or
transition metal complexes such as, for example, manganese-, iron-,
cobalt-, ruthenium- or molybdenum-salen complexes or carbonyl
complexes. Manganese, iron, cobalt, ruthenium, molybdenum, titanium,
vanadium and copper complexes with nitrogen-containing tripod ligands
and cobalt-, iron-, copper- and ruthenium-ammine complexes may also be
used as bleach c,~talysts.
Suitable enzymes are those from the class of proteases, lipases,
amylases, cellulases and mixtures thereof. Enzymes obtained from
bacterial strains or fungi, such as Bacillus subtilis, Bacillus licheniformis
and StreptomycE~s grise~us are particularly suitable. Proteases of the
subtilisin type arE: preferably used, proteases obtained from Bacillus lentus
being particularly preferrE~d. Of particular interest in this regard are
enzyme
mixtures, for example of protease and amylase or protease and lipase or
protease and cellulase or of cellulase and lipase or of protease, amylase
and lipase or protease, lipase and cellulase, but especially cellulase-
containing mixtures. Peroxidases or oxidases have also been successfully
used in some cases. The enzymes may be adsorbed to supports and/or
encapsulated in membrane materials to protect them against premature
CA 02313227 2000-07-28
decomposition. l-he percentage content of enzymes, enzyme mixtures or
enzyme granule, in the: tablets according to the invention may be, for
example, about 0.1 to 5°~'° by weight and is preferably from 0.1
to about 2%
by weight.
5 In addition, the detergent tablets according to the invention may also
contain components with a positive effect on the removability of oil and fats
from textiles by 'washing (so-called soil repellents). This effect becomes
particularly clear when a textile which has already been repeatedly washed
with a detergent according to the invention containing this oil- and fat-
10 dissolving component is soiled. Preferred oil- and fat-dissolving
components include, far example, nonionic cellulose ethers, such as methyl
cellulose and methyl hydroxypropyl cellulose containing 15 to 30% by
weight of metho:Kyl groups and 1 to 15% by weight of hydroxypropoxyl
groups, based ors the nonionic cellulose ether, and the polymers of phthalic
15 acid and/or terephthalic acid known from the prior art or derivatives
thereof,
more particularly polymers of ethylene terephthalates and/or polyethylene
glycol terephthalates or anionically and/or nonionically modified derivatives
thereof. Of these, the sulfonated derivatives of phthalic acid and
terephthalic acid polymers are particularly preferred.
20 The tablets may contain derivatives of diaminostilbenedisulfonic acid
or alkali metal salts thereof as optical brighteners. Suitable optical
brighteners are, for example, salts of 4,4'-bis-(2-anilino-4-morpholino-1,3,5-
triazinyl-6-amino)-stilbene-2,2'-disulfonic acid or compounds of similar
composition which contain a diethanolamino group, a methylamino group,
25 an anilino group or a 2-methoxyethylamino group instead of the morpholino
group. Brighteners of the substituted diphenyl styryl type, for example
alkali metal salt, of 4,4'-bis-(2-sulfostyryl)-diphenyl, 4,4'-bis-(4-chloro-3-
sulfostyryl)-diphenyl or 4-(4-chlorostyryl)-4'-(2-sulfostyryl)-diphenyl, may
also be present. Mixtures of the brighteners mentioned above may also be
CA 02313227 2000-07-28
26
used.
Dyes and perfumes are added to the detergent tablets according to
the invention to improve the aesthetic impression created by the products
and to provide the consumer not only with the required washing
performance but also with a visually and sensorially "typical and
unmistakable" product. Suitable perfume oils or perfumes include
individual perfume compounds, for example synthetic products of the ester,
ether, aldehyde, ketone, alcohol and hydrocarbon type. Perfume
compounds of the ester type are, for example, benzyl acetate,
phenoxyethyl isobutyratE:, p-tert.butyl cyclohexyl acetate, linalyl acetate,
dimethyl benzyl carbinyl acetate, phenyl ethyl acetate, linalyl benzoate,
benzyl formate, Eahyl methyl phenyl glycinate, allyl cyclohexyl propionate,
styrallyl propionate and benzyl salicylate. The ethers include, for example,
benzyl ethyl ether; the aldehydes include, for example, the linear alkanals
containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxy-
acetaldehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal;
the ketones include, for example, the ionones, a-isomethyl ionone and
methyl cedryl ke~tone; the alcohols include anethol, citronellol, eugenol,
geraniol, linalool, phenyl ethyl alcohol and terpineol and the hydrocarbons
include, above all, the terpenes, such as limonene and pinene. However,
mixtures of various perfumes which together produce an attractive perfume
note are preferably used. Perfume oils such as these may also contain
natural perfume mixtures obtainable from vegetable sources, for example
pine, citrus, jasmine, patchouli, rose or ylang-ylang oil. Also suitable are
clary oil, camomile oil, clove oil, melissa oil, mint oil, cinnamon leaf oil,
lime
blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil and
labdanum oil and orange blossom oil, neroli oil, orange peel oil and
sandalwood oil.
The softeners according to the invention normally contain less than
CA 02313227 2000-07-28
27
0.01 % by weight of dyes whereas perfumes can make up as much as 2%
by weight of the formulation as a whole.
The perfumes may be directly incorporated in the detergents
according to the invention, although it can also be of advantage to apply
the perfumes to suppart;s which strengthen the adherence of the perfume
to the washing and which provide the textiles with a long-lasting fragrance
through a slower releasE~ of the perfume. Suitable support materials are,
for example, cyclodextrins, the cyclodextrin/perfume complexes optionally
being coated with other auxiliaries.
In order to improve their aesthetic impression, the detergent tablets
according to the invention may be colored with suitable dyes. Preferred
dyes, which are not difficult for the expert to choose, have high stability in
storage, are not affected by the other ingredients of the detergents or by
light and do not have any pronounced substantivity for textile fibers so as
not to color them. Since the present invention relates to multiphase
detergent tablet;, considerable significance attaches to the coloring of
individual phases in order to underscore the differences in active character
between individu;~l phasEa. Examples of the effectivenes of such coloring
and of the success of relevant claims are sufficiently known from the
advertizing of denture cleaning preparations.
The tablets according to the invention are produced by first dry-
mixing the constituents o~f the individual phases, which may be completely
partly pregranulai:ed, and then forming/shaping, more particularly tabletting,
the resulting mixiFures using conventional processes for the production of
multiphase tablets. To produce the tablets according to the invention, the
premixes are compacted between two punches in a die to form a solid
compactate. This procE;ss, which is referred to in short hereinafter as
tabletting, comprises four phases, namely metering, compacting (elastic
deformation), pla:~tic deformation and ejection.
CA 02313227 2000-07-28
28
The tabletting process is carried out in commercially available tablet
presses which, in principle, may be equipped with single or double
punches. In the latter case, not only is the top punch used to build up
pressure, the boiaom punch also moves towards the top punch during the
tabletting process while the top punch presses downwards. For small
production volumes, it is preferred to use eccentric tablet presses in which
the punches) is/~~re fixed to an eccentric disc which, in turn, is mounted on
a shaft rotating <~t a certain speed. The movement of these punches is
comparable with the operation of a conventional four-stroke engine.
Tabletting can be carried out with a top punch and a bottom punch,
although several punches can also be fixed to a single eccentric disc, in
which case the number of die bores is correspondingly increased. The
throughputs of eccentric presses vary according to type from a few hundred
to at most 3,000 i:ablets per hour.
For larger throughputs, rotary tablet presses are generally used. In
rotary tablet presses, a relatively large number of dies is arranged in a
circle on a so-called die table. The number of dies varies - according to
model - between 6 and 55, although even larger dies are commercially
available. Top and bottom punches are associated with each die on the
die table, the tabletting pressures again being actively built up not only by
the top punch or bottom punch, but also by both punches. The die table
and the punches move about a common vertical axis, the punches being
brought into the filling, compaction, plastic deformation and ejection
positions by means of curved guide rails. At those places where the
punches have to be raised or lowered to a particularly significant extent
(filling, compaction, ejection), these curved guide rails are supported by
additional push-d~cwn members, pull-down rails and ejection paths. The die
is filled from a rigidly arranged feed unit, the so-called filling shoe, which
is
connected to a storage container for the compound. The pressure applied
CA 02313227 2000-07-28
29
to the premix can be individually adjusted through the tools for the top and
bottom punches, pressure being built up by the rolling of the punch shank
heads past adjustable pressure rollers.
To increase throughput, rotary presses can also be equipped with
two or more filling shoes. To produce two-layer or multiple-layer tablets,
several filling shoes are arranged one behind the other without the lightly
compacted first layer bE~ing ejected before further filling. Given suitable
process control, shell and bull's-eye tablets - which have a structure
resembling an onion skin - can also be produced in this way. In the case
of bull's-eye tablE~ts, the upper surface of the core or rather the core
layers
is not covered and thus remains visible. Rotary tablet presses can also be
equipped with single or multiple punches so that, for example, an outer
circle with 50 bores and an inner circle with 35 bores can be simultaneously
used for tablettinc~. ModE~rn rotary tablet presses have throughputs of more
than one million tablets per hour.
Tabletting machines suitable for the purposes of the invention can
be obtained, for example, from the following companies: Apparatebau
Holzwarth GbR, Asperq, Wilhelm Fette GmbH, Schwarzenbek, Hofer
GmbH, Weil, KILIAN, Cologne, KOMAGE, Kell am See, KORSCH Pressen
GmbH, Berlin, M~apag Maschinenbau AG, Bern (Switzerland) and Courtoy
N.V., Halle (BE/I'_U). C>ne example of a particularly suitable tabletting
machine is the model HPF 630 hydraulic double-pressure press
manufactured by LAEIS, D.
The tableia can be made in certain shapes and certain sizes,
consisting always of several phases, i.e. layers, inclusions or cores and
rings. Suitable shapes are virtually any easy-to-handle shapes, for
example slabs, ears, cubes, squares and corresponding shapes with flat
sides and, in particular, cylindrical forms of circular or oval cross-section.
This last embodiment encompasses shapes from tablets to compact
CA 02313227 2000-07-28
cylinders with a r~eight-to-diameter ratio of more than 1.
The portioned pressings may be formed as separate individual
elements which correspond to a predetermined dose of the detergent.
However, it is al~co possible to form pressings which combine several such
5 units in a single pressing, smaller portioned units being easy to break off
in
particular through the provision of predetermined weak spots. For the use
of laundry deten~ents in machines of the standard European type with
horizontally arranged mechanics, it can be of advantage to produce the
portioned pressings as cylindrical or square tablets, preferably with a
10 diameter-to-height ratio of about 0.5:2 to 2:0.5. Commercially available
hydraulic pressea, eccentric presses and rotary presses are particularly
suitable for the productioin of pressings such as these.
The three-dimensional form of another embodiment of the tablets
according to the invention is adapted in its dimensions to the dispensing
15 compartment of commercially available domestic washing machines, so
that the tablets can be introduced directly, i.e. without a dosing aid, into
the
dispensing com~~artment where they dissolve on contact with water.
However, it is of course readily possible to use the detergent tablets in
conjunction with ~~ dosing aid.
20 Another preferred multiphase tablet which can be produced has a
plate-like or slab-like structure with alternately thick long segments and
thin
short segments, ao that individual segments can be broken off from this "
multiphase bar" at the predetermined weak spots, which the short thin
segments represE~nt, and introduced into the machine. This "bar" principle
25 can also be embodied in other geometric forms, for example vertical
triangles which are only joined to one another at one of their longitudinal
sides. In this case, it is appropriate for optical reasons to make the base of
the triangle, by ~n~hich the individual segments are interconnected, as one
phase while the apex forms the second phase. In this embodiment,
CA 02313227 2000-07-28
31
different coloring ~~f the two phases is particularly attractive.
After pressing, the detergent tablets have high stability. The fracture
resistance of cylindrical tablets can be determined via the diametral fracture
stress. This in t~.~rn can be determined in accordance with the following
equation:
a=
2P
~Dt
where a represents the diametral fracture stress (DFS) in Pa, P is the force
in N which leads ~to the pressure applied to the tablet that results in
fracture
thereof, D is the diameter of the tablet in meters and t is its height.
Examples
Premixes were prepared by mixing surfactant-containing granules
with powder-form aftertreatment components and were tabletted in a
Korsch tablet press to form two-phase detergent tablets. Surfactant
granules 1, 2 and 3 had been produced in a 130-liter plowshare mixer
(Gebriader Lodign, Paderborn) and then dried in a fluidized-bed dryer.
After the coarse fractions (>_ 1.6 mm) and the fine particles (<_ 0.4 mm) had
been removed by sieving, the surfactant granules were mixed with the
aftertreatment components in a paddle mixer.
The composition of the surfactant granules is shown in Table 1.
CA 02313227 2000-07-28
32
Table 1: Surfactant granules [% by weight]
;~, p; ,.., , ~" ~ > , ::y y ' ~>
3 y. [ ;.>.: ,T s 3u' ,
~f''s ~~ F '.. w.,, f~ , '>a' . ,";~
.:r SF~ F~FF~~~, '~ FfisFd~F~~~ F~E~:'
~ a~F,. > v:$ t, ~ g
S 1 ' ~>33~~ '. F ~ 3 ~: ~ ~> 3 3 '
E p s, , "'~ , ,~:. X'~. s.; 3
I~ ~ ~ ~~~ 9 .~~~ ~ . , ~ ~ ~~
. _..~t.>, , ~~
y
Cs-~3 alkyl benzenesulfonate21.2 18.6 19.4
C~2-~g fatty alcohol sulfatE~8.5 5.4 5.2
C~2_~g fatty alcohol + 7 - 5.7 4.8
EO
C~2-~s alkyl-1,4-gl~~coside,- - 1.0
degree of
oligomerization 1.1
Soap 1.6 1.6 1.6
Sodium carbonate 17.0 16.6 17.0
Sodium silicate 5.6 5.4 5.6
Zeolite A (water-free active28.5 29.9 28.5
substance)
Optical brightene~~r 0.3 0.3 0.3
Na hydroxyethan~e-1,1-diphosphate0.8 0.8 0.8
Acrylic acid/maleic acid 5.6 5.4 5.6
copolymer
Water, salts Balance Balance Balance
Two-layer detergE:nt tablets were produced from the premixes
(surfactant granules + aftertreatment components) in a Korsch rotary press,
the first layer malting up 75% and the second layer 25% of the total weight
of each tablet. The diameter of the tablets was 44 mm.
Tables 2, 3 and 4 below show the phase compositions of the
detergent tablets. The figures in the columns of the Table represent the
quantity of the particular ingredient in the particular phase of the tablet,
i.e.
the figures in each column add up to 100%. The quantity of the particular
ingredient in the tablet as a whole can easily be calculated from the
percentage content of the individual phases in the tablet. Commensurate
with the different tablet weights (37.5 g ~ 1 %,caused by slight variations in
the feed of the premix to the die of the press), the tablet hardnesses varied
CA 02313227 2000-07-28
33
by about ca. ~ 10%, the disintegration times by ca. 5 seconds. The tablet
hardnesses and c~isintegr-ation times are also shown in the Tables.
Table 2: Detergent tablets - composition [% by weight], physical properties
B~ ~~~
a B
~
I~~
- n.L...~~. : J
, ;.-
, .;''.o-7~~
..FI,@~~f>~BIBY,B~YB,B~( li ~
~E . W
~ 6~1
5, :,
! ~EZ.
4
Invention Comparison
Example
Layer Layer Layer Layer
1 2 . 1 2
Granules 1 64.0 50.7 64.2 51.3
Sodium perboratE: monohydrate23.7 - 23.7 -
Tetraacetyl ethylE;nediamine- 29.0 - 29.0
Enzyme granules.* - 10.0 - 10.0
Foam inhibitor ~ 3.5 1.1 3.5 1.1
Repelotex SRP 4** 1.1 1.1 1.1 1.1
Perfume 0.5 0.5 0.5 0.5
Zeolite A 2.2 1.4 2.0 2.0
Cellulose**** 5.0 5.0 5.0 5.0
,: .t 'W g,.,~ ,.. s y,' ,
~'rt'~~~ > ~le~"I~ c'~ ~. ' . k7 >y II ':,
3,>,,,. E ; ~ a G, ~ ';~~3 .~8~
; 3 ~. ;
~
B >~f v
S E ~~ ~ / 3" I ~ B F 1~E~,'~EBE,IB,;" . ,
J > . ;?f
P,~
~' '. F - > - zYr ': E , ; ~., ' w ~I~
~e~ ,. & " ,.' ~ ~ 4
,> ,P,: . k ~'. i B ~ ~~,'~~:: E ,.
8 #.. .." ~E , E ,. , ".
~ ~ , .. ",~I E>"I
~ B a .7 >
~ ~ ; t,:., ".:'.",~
> ~~~ s B
~ ~ ~~~
'~ ~
f ~"
~ ~ ~
'~
.
.. . .. @ z .:
eat E > , ':a~"ta ~ ;~v ~ ;; '" 3
.< Era EF I ">B:>
, ia.:r3 ~F. f,:n,$ e,
. p .
.. ,~~ E
C, ",r S
B , . t -
1
, ;
,
.
,
>
Difference in surfi~ctant 4.16% 4.03%
content
Ratio of surfactant contents1.26:1 1.25:1
Ratio zeolite A*** 1.57:1 1:1
Tablet hardness 36-48N 39-47N
I Disintegration time ~T 17-23 > 60
secs. secs.
* Enzyme ciranules of protease, cellulase, amylase, lipase on a
support (starch), coated
** Repelotex SRP 4 us a terephthalic acid/ethylene glycol, polyethylene
glycol ester made by Rhone Poulenc
CA 02313227 2000-07-28
34
*** Adsorption component with an oil adsorption capacity of 30g/100g,
average p;~rticle size < 10 pm
**** Compacted cellulose (particle size: 90% by weight > 400 Nm)
Table 3: Detergent tablets - composition [% by weight], physical properties
6~L~s~ ~ 6 ~~f
~ .
~ 3
~a
6 ~# ~ ~ 6.36
a +S a
i a ~
~~ 3 '
_. ~
t ~
' , :':
. =; ..
. < E"
, , .;
" ., s'
I a s . ~
~;".I
~ d.
" ,z
Invention Comparison
Example
Layer Layer Layer Layer
1 2 1 2
Granules 2 65.8 42.1 66.8 41.1
Sodium perboratE~ monohydrate17.8 17.8 17.8 17.8
Tetraacetyl ethylE:nediamine- 29.0 - 29.0
Enzyme granules 3.3 - 3.3 -
Foam inhibitor 3.5 3.5 3.5 3.5
Repelotex SRP 4 1.1 1.1 1.1 1.1
Perfume 0.5 0.5 0.5 0.5
Zeolite A ~ 3.0 1.0 2.0 2.0
Cellulose* 5.0 5.0 5.0 5.0
1~~~'~~t~ Ct~~t'erw'~ ~ ~ ;.. ~,, ~ ~ , ~ 2~
h $>P ~ ~. ~ ~~ ~
Y ~ t ':
~
. n ~ . . ,
. . .p e~t 'i's ,:.k
/... z3 2 SF "6 :, ,., < a 3
f-- ,.. '.;. ,~, F.6C
'f~~ 'a~ , ~ 3 ~' ~ .f,..
,u.6~~~,. ~3 ~ ~ ' ~~~~fs,.
q
, ~
RF~,~..
B.
6~
~ ~
1 .
.a:F~ s;
~" '. ~ 3 ~~ ~ ~ R" 3 E ':'ts '~t3=~ -. ~,
.~~~~'~~~6 '~ a~ k b. ~h .e,
Y ~
,E ~~ ~ a
s r 6,:. , y' ~ < 9'6 .
,.~
, , ~' .. '~ .. .:; ,'.ro' ,:= f '.
~. , ,.r::
'~
_ ~ .
~ 33
~~ _
Difference in surf~~ctant 7.42% 8.05%
content
Ratio of surfactant contents1.56:1 16.3:1
~
Ratio zeolite A*** 3:1 1:1
Tablet hardness 36-48 39-49
N N
Disintegration time 20-28 > 60
secs. secs.
" Compacten cellulose (particle size: 90% by weight > 400 pm)
CA 02313227 2000-07-28
35
Table 4: Detergent tablets - composition [% by weight], physical properties
.4 a,~.FfiSB ~~ :
ja.a8 jp$ca
2.~ ~ ~ ~
v$ 3 a
~
'
~~
~~
>a 3
~F $
~ 1 ~ ~
'
rt~~ll~
~3~'~r
~~3
_ e$
.- , 6 s f
....-.....-s................. , : $
'' "" : ,
' ,: ,
."'
, a,~,
,_,
Invention Comparison
Example
Layer Layer Layer Layer
1 2 1 2
Granules 3 ~ 65.1 43.8 66.3 42.5
Sodium perborate monohydrate7.0 50.0 7.0 50.0
Tetraacetyl ethylE:nediamine9.8 - 9.8 -
Enzyme granule~~* ~ 3.3 - 3.3 -
Foam inhibitor 4.7 - 4.7 -
Repelotex SRP 4* 1.4 - 1.4 -
Perfume 0.5 0.5 0.5 0.5
Zeolite A 3.2 0.7 2.0 2.0
Cellulose* 5.0 5.0 5.0 5.0
~:.
" k ._ ~:,..,
,a ~,. .
.. ~ " ..< : ,. ~ , 3.
.. > ,_ ~
_
Ir"a ~ ~ _ 6 ,3 a
ra.6, ~,~ ~ ~ ~
~a as
R,
~ 9 ' a
f
~
~
~. 3
~ .
~.,~...... .
S "'i
a -.~. - 4 # . ~.". r
Y. ...-<.sd.. s.,. ~'F : ,..c<.
, ,.,.'~ :$~ 3~ ~~ ,.,
, .~~ 4:. .:
... ~s. a s;, ~.. .. w~.
<.. ~ ~ ~ a.. :: I3 ~~~~ ~a~,sx , ~ .
~ , Y~" .,
7 , :.
, " ~
p a,. .
".' <"~sa 0 ', m
'a~, 33.>.; , '. r, ,
aa$. ,:: .nw
~~:.:. i~~ 3$ .:~,~ , n' r
C ~~? ""7 w L~ #
5~3~~ O ';
m, L~,'; ,~ , . :-_$f,.
, ,
Difference in surfactant 6.81 7.62%
content %
Ratio of surfactant contents1.48:1 1.56:1
Ratio zeolite A 4.57:1 1:1
Tablet hardness 43-51 38 -
N 47 N
Disintegration time 14 -19 > 60
secs. secs.
* Enzyme granules of protease, cellulase, amylase, lipase on a
support (starch), coated
** Repelotex SRP 4 is a terephthalic acid/ethylene glycol, polyethylene
glycol ester made by Rhone Poulenc
*** Adsorption, component with an oil adsorption capacity of 30g/100g,
average p<~rticle size < 10 pm
**** Compacte~~ cellulose (particle size: 90% by weight > 400 pm
