CA2313227A1 - Multiphase detergent tablets - Google Patents

Abstract

The invention relates to two-phase or multiphase detergent tablets of compacted particulate detergent comprising surfactant(s), builder(s) and optionally other detergent ingredients, in which 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 20 g/100 g and an average particle size below 50 µm, based on the weight of the phase, being present in larger quantities in the phase(s) with the higher surfactant content than in the phase(s) with the lower surfactant content. Through this combination of surfactant content and oil adsorption component in the individual phases of the tablet, multiphase tablets with an outstanding property profile are obtained.

Description

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 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.

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 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 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 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.

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 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 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 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 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 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):

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 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 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 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 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 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 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 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 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 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 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 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 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 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 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.

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 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 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, 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=

~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.

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 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.

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 -, ;
, .
, >

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 *** 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 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) 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 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 -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

Claims (45)

1. A two- or more-phase detergent tablet of compacted particulate detergent comprising surfactants, builders and optionally other detergent ingredients, wherein the surfactant content of the individual phases of the tablet varies by 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 µm, based on the weight of the phase, is present in larger quantities in the phases with the higher surfactant content than in the phases with the lower surfactant content.

2. Detergent tablets as claimed in claim 1, wherein the content of component A in the phases richer in surfactant is higher by at least 0.3% by weight, based on the weight of the individual phase, than in the phases with the lower surfactant content.

3. Detergent. tablets as claimed in claim 1, wherein the content of component A in the phases richer in surfactant is higher by at least 0.5% by weight based on the weight of the individual phase, than in the phases with the lower surfactant content.

4. Detergent tablets as claimed in claim 1, wherein the content of component A in the phases richer in surfactant is higher by at least 1% by weight based on the weight of the individual phase, than in the phases with the lower surfactant content.

5. Detergent tablets as claimed in claim 1 or 2, wherein the relative quantity ratio of component A between the individual phases is greater than the relative quantity ratio of the surfactants between the individual phases.

6. Detergent tablets as claimed in any of claims 1 to 5, wherein component A has an oil adsorption capacity of at least 50g/100 g.

7. Detergent tablets as claimed in any of claims 1 to 5, wherein component A has an oil adsorption capacity of at least 80g/100g.

8. Detergent tablets as claimed in any of claims 1 to 5, wherein component A has an oil adsorption capacity of at least 120g/100g.

9. Detergent tablets as claimed in any of claims 1 to 5, wherein component A has an oil adsorption capacity of at least 140g/100g.

10. Detergent tablets as claimed in any of claims 1 to 9, wherein component A has an average particle size below 50 µm.

11. Detergent tablets as claimed in any of claims 1 to 9, wherein component A has an average particle size below 20 µm.

12. Detergent tablets as claimed in any of claims 1 to 9, wherein component A has an average particle size below 10 µm.

13. Detergent tablets as claimed in any of claims 1 to 12, wherein component A is selected from silicates and/or alumosilicates.

14. Detergent tablets as claimed in any of claims 1 to 12, wherein component A is selected from the group of silicas and/or zeolites.

15. Detergent tablets as claimed in any of claims 1 to 14, wherein the phases of the tablets are in the form of layers.

16. Detergent tablets as claimed in any of claims 1 to 15, wherein the surfactants are introduced into the phases of the tablets through one or more batches of surfactant-containing granules.

17. Detergent tablets as claimed in claim 16, wherein the same surfactant granules are used in all phases of the tablets.

18. Detergent tablets as claimed in claims 16 and 17, comprising two layers which comprise the same surfactant granules in different quantities.

19. Detergent tablets as claimed in any of claims 1 to 18, comprising anionic and nonionic surfactants.

20. Detergent tablets as claimed in claim 19, wherein the ratio of anionic surfactants to nonionic surfactants is between 10:1 and 1:10.

21. Detergent tablets as claimed in claim 19, wherein the ratio of anionic surfactants to nonionic surfactants is between 7.5:1 and 1:5.

22. Detergent tablets as claimed in claim 19, wherein the ratio of anionic surfactants to nonionic surfactants is between 5:1 and 1:2.

23. Detergent tablets as claimed in any of claims 1 to 22, wherein at least one phase of the tablets is free from nonionic surfactants.

24. Detergent tablets as claimed in any of claims 1 to 23, wherein at least one phase of the tablets contains alkyl polyglycosides.

25. Detergent tablets as claimed in any of claims 1 to 24, wherein at least one phase of the tablets is free from anionic surfactants.

26. Detergent tablets as claimed in any of claims 1 to 25, wherein a disintegration aid is present in quantities of 0.5 to 10% by weight, based on the weight of the tablet.

27. Detergent tablets as claimed in claim 26, wherein the disintegration aid is a cellulose-based disintegration aid.

28. Detergent tablets as claimed in claim 26 or 27 wherein the disintegration aid I spresent in granulated, cogranulated or compacted form.

29. Detergent tablets as claimed in claim 26, 27 or 28 wherein the disintegration aid comprises 3 to 7% by weight, based on the weight of the tablet.

30. Detergent tablets as claimed in claim 26, 27 or 28 wherein the disintegration aid comprises 4 to 6% by weight, based on the weight of the tablet.

31. Detergent tablets as claimed in any of claims 1 to 30, additionally comprising one or more substances from the group of bleaching agents, bleach activators, enzymes, pH regulators, perfumes, perfume carriers, fluorescers, dyes foam inhibitors, silicone oils, redeposition inhibitors, optical brighteners, discoloration inhibitors, dye transfer inhibitors and corrosion inhibitors.

32. A process for the production of two- or more-phase detergent tablets containing surfactants, builders and optionally other detergent ingredients by tabletting, wherein a particulate premix of at least one batch of surfactant-containing granules and at least one subsequently incorporated powder-form component is formed into tablets, the surfactant content of the individual phases of the tablets varying by 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 µm, bared on the weight of the phase, is present in larger quantities in the phases with the higher surfactant content than in the phases with the lower surfactant content.

33. A process as claimed in claim 32, wherein the granules are produced by a conventional granulation process selected from mixer and pan granulation, fluidized bed granulation, extrusion, pelleting or compacting.

34. A process as claimed in claim 33 or 34, wherein the granules have particle sizes of 10 to 4,000 µm.

35. A process as claimed in Claim 34, wherein the granules have particle sizes of preferably between 100 and 2,000 µm.

36. A process as claimed in Claim 34, wherein the granules have particle sizes of between 600 and 1,400 µm.

37. A process as claimed in any of claims 32 to 36, wherein the powder-form component(s) subsequently incorporated contain the component A.

38. A process as claimed in any of claims 32 to 37, wherein the premix to be tabletted has a bulk density of at least 500 g/l.

39. A process as claimed in claim 38, wherein the premix to be tabletted has a bulk density of at least 600 g/l.

40. A process as claimed in claim 38, wherein the premix to be tabletted has a bulk density above 700 g/l.

41. A process as claimed in any of claims 32 to 40, wherein one of the powder-form components subsequently incorporated is a faujasite zeolite with particle sizes below 100 µm, and makes up at least 0.2% by weight, of the premix to be tabletted.

42. A process as claimed in claim 41, wherein the particle sizes are below 10 µm.

43. A process as claimed in claim 41, wherein the particle sizes are below 5 µm.

44. A process as claimed in any of claims 41 to 43, wherein the faujasite zeolite makes up at least 0.5% by weight.

45. A process as claimed in any of claims 41 to 43, wherein the faujasite zeolite makes up more than 1% by weight.