CA2314035A1 - Detergent tablets, especially for machine dishwashing - Google Patents

Abstract

Disintegration aids for detersive tablets, said aids firstly shortening the disintegration time of the tablet, or parts of the tablet, in customary domestic dishwashers and secondly being easy to incorporate into the mixtures for compression without the loss of the active form, for phosphate-containing formulations, are finely divided auxiliaries especially zeolites. The disintegration time of detergent tablets can be improved if they contain from 20 to 95% by weight of phosphates) and from 0.1 to 9% by weight of zeolite (s) .

Description

DETERGENT TABLETS, ESPECIALLY FOR MACHINE DI
Field of the Invention The present invention relates to detergent tablets comprising builders and bleaches. The invention relates in particular to detergent tablets for machine dish-washing which are wholly or partly dissolution-accelerated.
Background of the Invention Detergent tablets have been widely described in the prior art and are enjoying increasing popularity among users owing to the ease of dosing. Tableted detergents have a number of advantages over their powder-form counterparts: they are easier to dose and to handle, and have storage and transport advantages owing to their compact structure. Consequently, detergent tablets have been described comprehensively in the patent literature as well. One problem which occurs again and again in connection with the use of detersive tablets however, is the inadequate disintegration and dissolution rate of the tablets under application conditions. Since tablets of sufficient stability, i.e., dimensional stability and fracture resistance, can be produced only by means of relatively high compression pressures, there is severe compaction of the tablet constituents and, consequently, retarded disintegration of the tablet in the aqueous liquor, leading to excessively slow release of the active substances in the cleaning operation.
In the field of detergents it is possible inter alia, in accordance with the teaching of European patent EP-B-0 523 099, to use the disintegrants known from drug manufacture. Disintegrants mentioned include swellable phyllosilicates such as bentonites, natural substances and natural substance derivatives based on starch and on cellulose, alginates and the like, potato starch, methylcellulose and/or hydroxypropylcellulose. These disintegrants may either be mixed with the granules for compression or else incorporated into the granules for compression.
International Patent Application WO-A-96/06156 likewise indicates that the incorporation of disintegrants into detergent tablets may be of advantage. Here again, typical disintegrants specified include micro-crystalline cellulose, sugars such as sorbitol, and phyllosilicates, especially finely divided and swellable phyllosilicates of the bentonite and smectite type. Substances which contribute to the formation of gas, such as citric acid, bisulfate, bicarbonate, carbonate and percarbonate, are also cited as possible disintegration aids.
According to EP-A-0 711 827, the use of particles consisting predominantly of citrate, which has a certain solubility in water, has the secondary consequence also of an accelerated disintegration of the tablets. It is hypothesized that the dissolution of the citrate brings about a local increase in the ionic strength during a transition period, thereby suppressing the gelling of surfactants, as a consequence of which the disintegration of the tablet is not hindered. According to this patent application, therefore, citrate is not a conventional disintegrant but acts, instead, as an antigelling agent.
Detergent tablets comprising cellulose-based disintegrants in granular or optionally cogranulated form are described in German Patent Applications DE
197 09 991 (Stefan Herzog) and DE 197 10 254 (Henkel) and in International Patent Applications VJ098/40462 (Stefan Herzog) and ~n1O98/40463 (Henkel). These documents also contain details on the production of ' - 3 -granulated, compacted or cogranulated cellulose disintegrants.
In the production of drug tablets, the abovementioned proposed solutions lead to the desired success . In the detergent field, although they do contribute to improving the disintegration properties of tablets with a washing or cleaning activity, the improvement achieved is in many cases inadequate. Additionally, the use of the proposed disintegration aids in detersive tablets for machine dishwashing may lead to specific properties which are completely unknown to drugs or laundry detergents.
Sumanary of the Invention It is an object of the invention to provide a disintegration aid for detersive tablets which on the one hand shorten the disintegration time of the tablet, or parts of the tablet, in standard domestic dishwashing machines, but on the other hand is easy to incorporate into the mixtures for compression without losing its active form. Relative to the disintegrants described in the prior art, the activity should not be restricted only to the disintegration effect; instead, the auxiliary should as far as possible take over further functions in the cleaning process.
It has now been found that addition of small amounts of finely divided, preferably essentially water-insoluble auxiliaries, especially zeolite, to phosphate-containing detergent tablets accelerates the solubility of individual phases or of the entire tablet.
The invention provides detergent tablets comprising builders and bleaches and, optionally, further customary detergent ingredients and having a phosphate content of from 20 to 95% by weight, said tablets further comprising from 0.1 to 9% by weight of a finely divided auxiliary having an average particle size of less than 100 Vim.
The finely divided auxiliaries are preferably used in even finer form, so that in preferred detergent tablets the finely divided auxiliary has an average particle size of less than 40 Vim, preferably less than 20 Vim, and in particular less than 10 Vim.
Detailed Description of the Invention The particle size distribution of the auxiliary used is the essential feature for the success of the present invention, the nature of the auxiliary used playing only a minor role. However, it has been found that substances of relatively low solubility in water, surprisingly, provide better effects, so that the finely divided auxiliary in preferred detergent tablets is essentially water-insoluble.
In the context of the present invention, the term "essentially water-insoluble" characterizes substances whose solubility in water is negligibly small.
Milligram amounts, at most, of such substances having negligibly small water solubilities dissolve in one liter of water.
From the group of the finely divided, preferably water-insoluble auxiliaries, in addition to pyrogenic silicas, zeolite in particular has proven particularly suitable. Particularly preferred detergent tablets of the invention comprise zeolite as finely divided auxiliary.
There follows a description of the most important ingredients of the detergent tablets of the invention.
In machine dishwashing compositions in particular, phosphates are used as builder substances; however, _ _ 5 -their use is also possible with advantage in laundry detergents, provided such a use is not to be avoided on ecological grounds. Among the large number of commercially available phosphates, the alkali metal phosphates, with particular preference being given to pentasodium and pentapotassium triphosphate (sodium and potassium tripolyphosphate, respectively), possess the greatest importance in the detergent industry.
Alkali metal phosphates is the collective term for the alkali metal (especially sodium and potassium) salts of the various phosphoric acids, among which metaphosphoric acids (HP03)n and orthophosphoric acid H3P04, in addition to higher-molecular-mass representatives, may be distinguished. The phosphates combine a number of advantages: they act as alkali carriers, prevent limescale deposits on machine components, and lime incrustations on fabrics, and additionally contribute to cleaning performance.
Sodium dihydrogen phosphate, NaH2P04, exists as the dihydrate (density 1.91 g cm-3, melting point 60°) and as the monohydrate (density 2.04 g cm-3). Both salts are white powders of very ready solubility in water which lose the water of crystallization on heating and undergo conversion at 200°C into the weakly acidic diphosphate (disodium dihydrogen diphosphate, Na2H2Pz0~) and at the higher temperature into sodium trimetaphosphate (Na3P309) and Maddrell's salt (see below). NaHzP04 reacts acidically; it is formed if phosphoric acid is adjusted to a pH of 4.5 using sodium hydroxide solution and the slurry is sprayed. Potassium dihydrogen phosphate (primary or monobasic potassium phosphate, potassium biphosphate, PDP), KHzP04, is a white salt with a density of 2.33 g cm-3, has a melting point of 253° [decomposition with formation of potassium polyphosphate (KP03)X], and is readily soluble in water.

Disodium hydrogen phosphate (secondary sodium phosphate), Na2HP04, is a colorless, crystalline salt which is very readily soluble in water. It exists in anhydrous form and with 2 mol (density 2.066 g cm-3, water loss at 95°) , 7 mol (density 1.68 g cm-3, melting point 48° with loss of 5 H20), and 12 mol of water (density 1.52 g cm-3, melting point 35° with loss of 5 H20), becomes anhydrous at 100°, and if heated more severely undergoes transition to the diphosphate Na4P20~. Disodium hydrogen phosphate is prepared by neutralizing phosphoric acid with sodium carbonate solution using phenolphthalein as indicator.
Dipotassium hydrogen phosphate (secondary or dibasic potassium phosphate), KzHP04, is an amorphous white salt which is readily soluble in water.
Trisodium phosphate, tertiary sodium phosphate, Na3P04, exits as colorless crystals which as the dodecahydrate have a density of 1.62 g cm-3 and a melting point of 73-76°C (decomposition), as the decahydrate (corresponding to 19-20% P205) have a melting point of 100°C, and in anhydrous form (corresponding to 39-40%
P205) have a density of 2.536 g cm-3. Trisodium phosphate is readily soluble in water, with an alkaline reaction, and is prepared by evaporative concentration of a solution of precisely 1 mol of disodium phosphate and 1 mol of NaOH. Tripotassium phosphate (tertiary or tribasic potassium phosphate), K3P04, is a white, deliquescent, granular powder of density 2.56 g cm-3, has a melting point of 1340°, and is readily soluble in water with an alkaline reaction. It is produced, for example, when Thomas slag is heated with charcoal and potassium sulfate. Despite the relatively high price, the more readily soluble and therefore highly active potassium phosphates are frequently preferred in the cleaning products industry over the corresponding sodium compounds.

_ _ 7 -Tetrasodium diphosphate (sodium pyrophosphate), Na4P20~, exists in anhydrous form (density 2.534 g cm-3, melting point 988°, 880° also reported) and as the decahydrate (density 1.815-1.836 g cm-3, melting point 94° with loss of water). Both substances are colorless crystals which dissolve in water with an alkaline reaction. Na4P20~ is formed when disodium phosphate is heated at > 200° or by reacting phosphoric acid with sodium carbonate in stoichiometric ratio and dewatering the solution by spraying. The decahydrate complexes heavy metal salts and water hardeners and therefore reduces the hardness of the water. Potassium diphosphate (potassium pyrophosphate) , K4P20~, exists in the form of the trihydrate and is a colorless, hygroscopic powder of density 2.33 g cm-3 which is soluble in water, the pH of the 1% strength solution at 25° being 10.4.
Condensation of NaHzP04 or of KHzP04 gives rise to higher-molecular-mass sodium and potassium phosphates, among which it is possible to distinguish cyclic representatives, the sodium and potassium metaphos-phates, and catenated types, the sodium and potassium polyphosphates. For the latter in particular a large number of names are in use: fused or calcined phosphates, Graham's salt, Kurrol's and Maddrell's salt. All higher sodium and potassium phosphates are referred to collectively as condensed phosphates.
The industrially important pentasodium triphosphate, Na5P301o (sodium tripolyphosphate) , is a nonhygroscopic, white, water-soluble salt which is anhydrous or crystallizes with 6 H20 and has the general formula Na0- [P (O) (ONa) -O] n-Na where n - 3 . About 17 g of the anhydrous salt dissolve in 100 g of water at room temperature, at 60° about 20 g, at 100° around 32 g;
after heating the solution at 100°C for two hours, about 8% orthophosphate and 15% diphosphate are _ 8 _ produced by hydrolysis. For the preparation of pentasodium triphosphate, phosphoric acid is reacted with sodium carbonate solution or sodium hydroxide solution in stoichiometric ratio and the solution is dewatered by spraying. In a similar way to Graham's salt and sodium diphosphate, pentasodium triphosphate dissolves numerous insoluble metal compounds (including lime soaps, etc). Pentapotassium triphosphate, KSP301o (potassium tripolyphosphate), is commercialized, for example, in the form of a 50% strength by weight solution (> 23% Pz05, 25% K20) . The potassium polyphosphates find broad application in the laundry detergents and cleaning products industry. There also exist sodium potassium tripolyphosphates, which may likewise be used for the purposes of the present invention. These are formed, for example, when sodium trimetaphosphate is hydrolyzed with KOH:
(NaP03 ) 3 + 2 KOH ~ Na3K2P301o + H20 They can be used in accordance with the invention in precisely the same way as sodium tripolyphospate, potassium tripolyphosphate, or mixtures of these two;
mixtures of sodium tripolyphosphate and sodium potassium tripolyphosphate, or mixtures of potassium tripolyphosphate and sodium potassium tripolyphosphate, or mixtures of sodium tripolyphosphate and potassium tripolyphosphate and sodium potassium tripolyphospate, may also be used in accordance with the invention.
The detergent tablets of the invention comprise the phosphates) in amounts of from 20 to 95% by weight, based in each case on the tablet. In preferred detergent tablets, the phosphate content is from 30 to 92.5% by weight, preferably from 40 to 90% by weight, and in particular from 50 to 85% by weight, based in each case on the tablet.

As the second constituent from the group of the builders, the detergent tablets of the invention, in particularly preferred embodiments, comprise zeolite.
The use of zeolite in the stated amounts and with the stated particle size distribution leads to an accelerated dissolution of the tablet, and/or of the phases of the tablet having the stated composition. The finely crystalline, synthetic zeolite used, containing bound water, is preferably zeolite A and/or X, Y and/or P. A particularly preferred zeolite P is Zeolite MAP~
(commercial product from Crosfield). A product available commercially and able to be used with preference in the context of the present invention, for example, is a cocrystallizate of zeolite X and zeolite A (approximately 80% by weight zeolite X), which is sold by CONDEA Augusta S.p.A. under the brand name VEGOBOND AX~ and may be described by the formula nNa20~ (1-n) KZO~A1203~ (2-2. 5) Si02~ (3 . 5-5. 5) H20.
These amounts are based on the water-free, i.e., unhydrated granular compound or as a kind of "powdering" for the zeolite. Suitable zeolites contain preferably from 18 to 22% by weight, in particular from 20 to 22% by weight, of bound water.
Zeolite has the general formula M2/nO~A1203~xSiOz~yH20, where M is a cation of valence n, x is greater than or equal to 2, and y may adopt values between 0 and 20.
The zeolite structures are formed by the linkage of A104 tetrahedra to Si04 tetrahedra, this network being occupied by cations and water molecules. The cations in these structures are relatively mobile and may, to differing extents, be replaced by other cations. The intercrystalline "zeolitic" water may, depending on zeolite type, be given off continuously and reversibly, while with certain zeolite types there are structural changes associated with the release and acceptance, respectively, of water.
Within the structural subunits, the "primary bonding units" (A104 tetrahedra and Si04 tetrahedra) form so-called "secondary binding units", which possess the form of single or multiple rings. Thus in different zeolites, for example, 4-, 6- and 8-membered rings occur (designated S4R, S6R and S8R), while other types are connected by four- and six-membered double ring prisms (the most frequent types are D4R as a tetragonal and D6R as a hexagonal prism). These "secondary sub-units" link different polyhedra which are designated using Greek letters. The most widespread of these is a polyhedron composed of six squares and eight equal-sided hexagons, which is referred to as "(3". Using these building units it is possible to realize multivarious different zeolites. At the present time, 34 natural zeolite minerals and approximately 100 synthetic zeolites are known.
The best-known zeolite, zeolite 4 A, is a cubic composite of (3 cages linked by D4R subunits. It belongs to zeolite structural group 3 and its three-dimensional network has pores of 2.2 A and 4.2 A in size; the formula unit within the unit cell can be described as Nalz [ (AlOz ) iz ( S iOz ) iz ] ~ 2 7 H20 .
In accordance with the invention it is preferred to use zeolites of the faujasite type. Together with zeolites X and Y, the mineral faujasite is one of the faujasite types within zeolite structural group 4, which is characterized by the double six-membered ring subunit D6R (cf. Donald W. Breck: "Zeolite Molecular Sieves", John Wiley & Sons, New York, London, Sydney, Toronto, 1974, page 92). In addition to said faujasite types, zeolite structural group 4 includes the mineral chabazite and gmelinite and also the synthetic zeolites R (chabazite type), S (gmelinite type), L, and ZK-5.
The two last-mentioned synthetic zeolites have no mineral analog.
Zeolites of the faujasite type are composed of [3 cages linked tetrahedrally via D6R subunits, the (3 cages being arranged similarly to the carbon atoms in a diamond. The three-dimensional network of the faujasite-type zeolites used in the process of the invention have pores of 2.2 and 7.4 A type; the unit cell further contains 8 cavities of approximately 13 A
in diameter and may be described by the formula Naes [ (A102) 8s (SiOz) lost ~ 264 H20. The network of zeolite X
contains a cavity volume of approximately 50%, based on the dehydrated crystal, which represents the greatest empty space of all known zeolites (zeolite Y: approx.
48% cavity volume; faujasite: approx. 47% cavity volume). (All data from: Donald W. Breck: "Zeolite Molecular Sieves", John Wiley & Sons, New York, London, Sydney, Toronto, 1974, pages 145, 176, 177.) In the context of the present invention, the term "faujasite-type zeolite" characterizes all three zeolites which form the faujasite subgroup of zeolite structural group 4. In accordance with the invention, therefore, not only zeolite X but also zeolite Y and faujasite, and mixtures of these compounds, may be used preferentially in accordance with the invention, preference being given to straight zeolite X.
It is also possible in accordance with the invention to use mixtures or cocrystallizates of faujasite-type zeolites with other zeolites, which need not necessarily belong to zeolite structural group 4.
The aluminum silicates used in accordance with the invention are available commercially and the methods of preparing them are described in standard monographs.

' - 12 -Examples of commercially available zeolites of the X
type may be described by the following formulae:
Nae6 L (A102 ) e6 ( S i02 ) los l ' x Hz0 K86 L (A102 ) 86 ( 512 ) 106 ~ ' X H20 Ca4oNa6 [ (A102) as (Si02) los] 'x Ha0 SrzlBa2a LA102) e6 (Si02) los] 'x H20 where x may adopt values between 0 and 276; they have pore sizes of from 8.0 to 8.4 A.
Zeolites of the Y type are also available commercially and may be described, for example, by the formulae Na56 L (A1~2) 56 (Sl~z) 136 'x H2~
Ks6 L (A1~2) 56 (512) 136 'x H2~
where x is a number between 0 and 276, and they have pore sizes of 8.0 A.
Preferred detergent tablets comprise, based in each case on the tablet, 0.25 to 7.5% by weight, preferably from 0.5 to 5% by weight, and in particular from 1 to 3% by weight, of zeolite, preferably zeolite X, Y
and/or P.
In addition to phosphates) and zeolite in the stated amounts, the detergent tablets of the invention may comprise further builders, which in some cases may also serve as alkali carriers. Mention may be made here in particular of silicates, carbonates, carboxylates, especially citrates, and polymers, which are described below.

Suitable crystalline, layered sodium silicates possess the general formula NaMSiX02X+1yH20. where M is sodium or hydrogen, x is a number from 1.9 to 4, y is a number from 0 to 20, and preferred values for x are 2, 3 or 4.
Crystalline phyllosilicates of this kind are described, for example, in European Patent Application EP-A-0 164 514. Preferred crystalline phyllosilicates of the formula indicated are those in which M is sodium and x adopts the value 2 or 3. In particular, both (3- and b-sodium disilicates Na2Si205~yH20 are preferred, (3-sodium disilicate, for example, being obtainable by the process described in International Patent Application WO-A-91/08171.
It is also possible to use amorphous sodium silicates having an Na20:Si02 modulus of from 1:2 to 1:3.3, preferably from 1:2 to 1:2.8, and in particular from 1:2 to 1:2 .6, which are dissolution-retarded and have secondary washing properties. The retardation of dissolution relative to conventional amorphous sodium silicates may have been brought about in a variety of ways - for example, by surface treatment, compounding, compacting, or overdrying. In the context of this invention, the term "amorphous" also embraces "X-ray-amorphous". This means that in X-ray diffraction experiments the silicates do not yield the sharp X-ray reflections typical of crystalline substances but instead yield at best one or more maxima of the scattered -radiation, having a width of several degree X

units of the diffraction angle. However, good builder properties may result, even particularly good builder properties, if the silicate particles in electron diffraction experiments yield vague or even sharp diffraction maxima. The interpretation of this is that the product s have microcrystalline regions with a size of from 10 to several hundred nm, values up to max.

50 nm and in particular up to max. 20 nm being preferred. So-called X-ray-amorphous silicates of this kind, which likewise possess retarded dissolution relative to the conventional waterglasses, are described, for example, in German Patent Application DE-A-44 00 024. Particular preference is given to compacted amorphous silicates, compounded amorphous silicates, and overdried X-ray-amorphous silicates.
Particularly suitable carbonates are alkali metal carbonates and hydrogen carbonates, particular importance being possessed by the sodium salts and, among them, by anhydrous sodium carbonate ("calcined soda"). It is further possible to use sodium carbonate decahydrate, sodium hydrogen carbonate, potassium carbonate, potassium carbonate 1.5-water ("potash hydrate"), potassium hydrogen carbonate, and mixtures of these.
Organic cobuilders which may be used in the detergent tablets of the invention are polycarboxylates/
polycarboxylic acids, polymeric polycarboxylates, aspartic acid, polyacetals, dextrins, further organic cobuilders (see below), and phosphonates. These classes of substance are described below.
Organic builder substances which may be used are, for example, the polycarboxylic acids, usable in the form of their sodium salts, the term polycarboxylic acids meaning those carboxylic acids which carry more than one acid function. Examples of these are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, malefic acid, fumaric acid, sugar acids, amino carboxylic acids, nitrilotriacetic acid (NTA), provided such use is not objectionable on ecological grounds, and also mixtures thereof. Preferred salts are the salts of the polycarboxylic acids such as citric acid, adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids, and mixtures thereof.

The acids per se may also be used. In addition to their builder effect, the acids typically also possess the property of an acidifying component and thus also serve to establish a lower and milder pH of laundry detergents or cleaning products. In this context, mention may be made in particular of citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid, and any desired mixtures thereof.
Also suitable as builders are polymeric poly-carboxylates; these are, for example, the alkali metal salts of polyacrylic acid or of polymethacrylic acid, examples being those having a relative molecular mass of from 500 to 70,000 g/mol.
The molecular masses reported for polymeric poly-carboxylates, for the purposes of this document, are weight-average molecular masses, Mw, of the respective acid form, determined basically by means of gel permeation chromatography (GPC) using a W detector.
The measurement was made against an external polyacrylic acid standard, which owing to its structural similarity to the polymers under investigation provides realistic molecular weight values. These figures differ markedly from the molecular weight values obtained using poly-styrenesulfonic acids as the standard. The molecular masses measured against polystyrenesulfonic acids are generally much higher than the molecular masses reported in this document.
Suitable polymers are, in particular, polyacrylates, which preferably have a molecular mass of from 2000 to 20,000 g/mol. Owing to their superior solubility, preference in this group may be given in turn to the short-chain polyacrylates, which have molecular masses of from 2000 to 10,000 g/mol, and with particular preference from 3000 to 5000 g/mol.

Also suitable are copolymeric polycarboxylates, especially those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with malefic acid. Copolymers which have been found particularly suitable are those of acrylic acid with malefic acid which contain from 50 to 90% by weight acrylic acid and from 50 to 10% by weight malefic acid. Their relative molecular mass, based on free acids, is generally from 2000 to 70,000 g/mol, preferably from 20,000 to 50,000 g/mol, and in particular from 30,000 to 40,000 g/mol.
The (co)polymeric polycarboxylates can be used either as powders or as aqueous solutions. The (co)polymeric polycarboxylate content of the compositions is preferably from 0.5 to 20% by weight, in particular from 3 to 10% by weight.
In order to improve the solubility in water, the polymers may also include allylsulfonic acids, such as allyloxybenzenesulfonic acid and methallylsulfonic acid, for example, as monomers.
Particular preference is also given to biodegradable polymers comprising more than two different monomer units, examples being those comprising, as monomers, salts of acrylic acid and of malefic acid, and also vinyl alcohol or vinyl alcohol derivatives, or those comprising, as monomers, salts of acrylic acid and of 2-alkylallylsulfonic acid, and also sugar derivatives.
Further preferred copolymers are those described in German Patent Applications DE-A-43 03 320 and DE-A-44 17 734, whose monomers are preferably acrolein and acrylic acid/acrylic acid salts, and, respectively, acrolein and vinyl acetate.

Similarly, further preferred builder substances that may be mentioned include polymeric amino dicarboxylic acids, their salts or their precursor substances.
Particular preference is given to polyaspartic acids and their salts and derivatives, which are disclosed in German Patent Application DE-A-195 40 086 to have not only cobuilder properties but also a bleach-stabilizing action.
Further suitable builder substances are polyacetals, which may be obtained by reacting dialdehydes with polyol carboxylic acids having 5 to 7 carbon atoms and at least 3 hydroxyl groups. Preferred polyacetals are obtained from dialdehydes such as glyoxal, glutaraldehyde, terephthalaldehyde and mixtures thereof and from polyol carboxylic acids such as gluconic acid and/or glucoheptonic acid.
Further suitable organic builder substances are dextrins, examples being oligomers and polymers of carbohydrates, which may be obtained by partial hydrolysis of starches. The hydrolysis can be conducted by customary processes; for example, acid-catalyzed or enzyme-catalyzed processes. The hydrolysis products preferably have average molecular masses in the range from 400 to 500,000 g/mol. Preference is given here to a polysaccharide having a dextrose equivalent (DE) in the range from 0.5 to 40, in particular from 2 to 30, DE being a common measure of the reducing effect of a polysaccharide in comparison to dextrose, which possesses a DE of 100. It is possible to use both maltodextrins having a DE of between 3 and 20 and dried glucose syrups having a DE of between 20 and 37, and also so-called yellow dextrins and white dextrins having higher molecular masses, in the range from 2000 to 30,000 g/mol.
The oxidized derivatives of such dextrins comprise their products of reaction with oxidizing agents which are able to oxidize at least one alcohol function of the saccharide ring to the carboxylic acid function.
Oxidized dextrins of this kind, and processes for preparing them, are known, for example, from European Patent Applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0 472 042 and EP-A-0 542 496 and from International Patent Applications WO 92/18542, WO
93/08251, WO 93/16110, WO 94/28030, WO 95/07303, WO
95/12619 and WO 95/20608. Likewise suitable is an oxidized oligosaccharide in accordance with German Patent Application DE-A-196 00 018. A product oxidized at C6 of the saccharide ring may be particularly advantageous.
Oxydisuccinates and other derivatives of disuccinates, preferably ethylenediamine disuccinate, are further suitable cobuilders. Ethylenediamine N,N'-disuccinate (EDDS) is used preferably in the form of its sodium or magnesium salts. Further preference in this context is given to glycerol disuccinates and glycerol trisuccinates as well. Suitable use amounts in formulations containing zeolite and/or silicate are from 3 to 15% by weight.
Examples of further useful organic cobuilders are acetylated hydroxy carboxylic acids and their salts, which may also be present in lactone form and which contain at least 4 carbon atoms, at least one hydroxyl group, and not more than two acid groups. Such cobuilders are described, for example, in International Patent Application WO 95/20029.
A further class of substance having cobuilder properties is represented by the phosphonates. The phosphonates in question are, in particular, hydroxyalkane- and aminoalkanephosphonates. Among the hydroxyalkanephosphonates, 1-hydroxyethane-1,1-diphos-phonate (HEDP) is of particular importance as a cobuilder. It is used preferably as the sodium salt, the disodium salt being neutral and the tetrasodium salt giving an alkaline (pH 9) reaction. Suitable aminoalkanephosphonates are preferably ethylenediamine-tetramethylenephosphonate (EDTMP), diethylenetriamine-pentamethylenephosphonate (DTPMP), and their higher homologs. They are used preferably in the form of the neutrally reacting sodium salts, e.g., as the hexasodium salt of EDTMP or as the hepta- and octa-sodium salt of DTPMP. As a builder in this case, preference is given to using HEDP from the class of the phosphonates. Furthermore, the aminoalkanephosphonates possess a pronounced heavy metal binding capacity.
Accordingly, and especially if the compositions also contain bleach, it may be preferred to use aminoalkanephosphonates, especially DTPMP, or to use mixtures of said phosphonates.
Furthermore, all compounds capable of forming complexes with alkaline earth metal ions may be used as cobuilders.
Besides the builders, important ingredients of detergents include particularly substances from the groups of the surfactants, bleaches, bleach activators, corrosion inhibitors, dyes, and fragrances. Important representatives from the classes of substances mentioned are described below.
Preferred detergent tablets further comprise one or more surfactants. In the detergent tablets of the invention it is possible to use anionic, nonionic, cationic and/or amphoteric surfactants, and/or mixtures thereof. From a performance standpoint, preference is given to mixtures of anionic and nonionic surfactants.
The total surfactant content of the tablets is from 5 to 60% by weight, based on the tablet weight, preference being given to surfactant contents of more than 15% by weight for laundry detergent tablets, while detergent tablets for machine dishwashing contain usually less than 3~ by weight of surfactant.
Anionic surfactants used are, for example, those of the sulfonate and sulfate type. Preferred surfactants of the sulfonate type are C9_13 alkylbenzenesulfonates, olefinsulfonates, i.e., mixtures of alkenesulfonates and hydroxyalkanesulfonates, and also disulfonates, as are obtained, for example, from Clz-is monoolefins having a terminal or internal double bond by sulfonating with gaseous sulfur trioxide followed by alkaline or acidic hydrolysis of the sulfonation products.. Also suitable are alkanesulfonates, which are obtained from Clz-la alkanes, for example, by sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization, respectively. Likewise suitable, in addition, are the esters of a-sulfo fatty acids (ester sulfonates), e.g., the a-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow fatty acids.
Further suitable anionic surfactants are sulfated fatty acid glycerol esters. Fatty acid glycerol esters are the monoesters, diesters and triesters, and mixtures thereof, as obtained in the preparation by esterification of a monoglycerol with from 1 to 3 mol of fatty acid or in the transesterification of triglycerides with from 0.3 to 2 mol of glycerol.
Preferred sulfated fatty acid glycerol esters are the sulfation products of saturated fatty acids having 6 to 22 carbon atoms, examples being those of caproic acid, caprylic acid, capric acid, myristic acid, lauric acid, palmitic acid, stearic acid, or behenic acid.
Preferred alk(en)yl sulfates are the alkali metal salts, and especially the sodium salts, of the sulfuric monoesters of Clz-C1g fatty alcohols, examples being those of coconut fatty alcohol, tallow fatty alcohol, lauryl, myristyl, cetyl or stearyl alcohol, or of Clo-Czo oxo alcohols, and those monoesters of secondary alcohols of these chain lengths. Preference is also given to alk (en) yl sulfates of said chain length which contain a synthetic straight-chain alkyl radical prepared on a petrochemical basis, these sulfates possessing degradation properties similar to those of the corresponding compounds based on fatty-chemical raw materials. From a detergents standpoint, the Clz-Cls alkyl sulfates and Clz-Cls alkyl sulfates, and also C14-Cis alkyl sulfates, are preferred. In addition, 2, 3-alkyl sulfates, which may for example be prepared in accordance with US Patents 3,234,258 or 5,075,041 and obtained as commercial products from Shell Oil Company under the name DAN~, are suitable anionic surfactants.
Also suitable are the sulfuric monoesters of the straight-chain or branched C~_zl alcohols ethoxylated with from 1 to 6 mol of ethylene oxide, such as 2-methyl-branched C9_11 alcohols containing on average 3.5 mol of ethylene oxide (EO) or Clz-is fatty alcohols containing from 1 to 4 EO. Because of their high foaming behavior they are used in cleaning products only in relatively small amounts, for example, in amounts of from 1 to 5% by weight.
Further suitable anionic surfactants include the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic esters and which constitute monoesters and/or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and especially ethoxylated fatty alcohols. Preferred sulfosuccinates comprise Cs_ls fatty alcohol radicals or mixtures thereof. Especially preferred sulfosuccinates contain a fatty alcohol radical derived from ethoxylated fatty alcohols which themselves represent nonionic surfactants (for description, see below).

Particular preference is given in turn to sulfosuccinates whose fatty alcohol radicals are derived from ethoxylated fatty alcohols having a narrowed homolog distribution. Similarly, it is also possible to use alk(en)ylsuccinic acid containing preferably 8 to 18 carbon atoms in the alk(en)yl chain, or salts thereof.
Further suitable anionic surfactants are, in particular, soaps. Suitable soaps include saturated fatty acid soaps, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and, in particular, mixtures of soaps derived from natural fatty acids, e.g., coconut, palm kernel, or tallow fatty acids.
The anionic surfactants, including the soaps, may be present in the form of their sodium, potassium or ammonium salts and also as soluble salts of organic bases, such as mono-, di- or triethanolamine.
Preferably, the anionic surfactants are in the form of their sodium or potassium salts, in particular in the form of the sodium salts.
Surfactants used in machine dishwashing compositions usually only comprise low-foaming nonionic surfactants.
Representatives from groups of the anionic, cationic or amphoteric surfactants, on the other hand, have a relatively minor importance. With particular preference, detergent tablets of the invention for machine dishwashing comprise nonionic surfactants.
In particularly preferred embodiments of the present invention, the detergent tablets of the invention comprise nonionic surfactants, especially nonionic surfactants from the group of the alkoxylated alcohols.
Nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, especially primary, alcohols having preferably 8 to 18 carbon atoms and on average from 1 to 12 mol of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical may be linear or, preferably, methyl-branched in position 2 and/or may comprise linear and methyl-branched radicals in a mixture, as are commonly present in oxo alcohol radicals. In particular, however, preference is given to alcohol ethoxylates containing linear radicals from alcohols of natural origin having 12 to 18 carbon atoms, e.g., from coconut, palm, tallow fatty or oleyl alcohol and on average from 2 to 8 EO per mole of alcohol. Preferred ethoxylated alcohols include, for example, Clz-14 alcohols containing 3 EO or 4 EO, C9_11 alcohol containing 7 EO, Cla-is alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, Clz-is alcohols containing 3 EO, 5 EO
or 7 EO, and mixtures thereof, such as mixtures of Clz-~4 alcohol containing 3 EO and Clz-la alcohol containing 5 EO. The stated degrees of ethoxylation represent statistical mean values, which for a specific product may be an integer or a fraction. Preferred alcohol ethoxylates have a narrowed homolog distribution (narrow range ethoxylates, NREs). In addition to these nonionic surfactants it is also possible to use fatty alcohols containing more than 12 EO. Examples thereof are tallow fatty alcohol containing 14 EO, 25 EO, 30 EO
or 40 EO.
As further nonionic surfactants, furthermore, use may also be made of alkyl glycosides of the general formula RO(G)X, where R is a primary straight-chain or methyl-branched aliphatic radical, especially an aliphatic radical methyl-branched in position 2, containing 8 to 22, preferably 12 to 18, carbon atoms, and G is the symbol representing a glycose unit having 5 or 6 carbon atoms, preferably glucose. The degree of oligomerization, x, which indicates the distribution of monoglycosides and oligoglycosides, is any desired number between 1 and 10; preferably, x is from 1.2 to 1.4.
A further class of nonionic surfactants used with preference, which are used either as sole nonionic surfactant or in combination with other nonionic surfactants, are alkoxylated, preferably ethoxylated, or ethoxylated and propoxylated, fatty acid alkyl esters, preferably having 1 to 4 carbon atoms in the alkyl chain, especially fatty acid methyl esters, as are described, for example, in Japanese Patent Application JP 58/217598, or those prepared preferably by the process described in International Patent Application WO-A-90/13533.
Nonionic surfactants of the amine oxide type, examples being N-cocoalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the fatty acid alkanolamide type, may be also be suitable.
The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, in particular not more than half thereof.
Further suitable surfactants are polyhydroxy fatty acid amides of the formula (I), R-CO-N- [Z] (I) where RCO is an aliphatic acyl radical having 6 to 22 carbon atoms, R1 is hydrogen or an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms, and [Z] is a linear or branched polyhydroxyalkyl radical having 3 to 10 carbon atoms and from 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are known substances which are customarily obtainable by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine, and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride.
The group of the polyhydroxy fatty acid amides also includes compounds of the formula (II) Ri-O-Rz R-CO-N- [Z] (II) where R is a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, R1 is a linear, branched or cyclic alkyl radical or an aryl radical having 2 to 8 carbon atoms and Rz is a linear, branched or cyclic alkyl radical or an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, preference being given to C1_4 alkyl radicals or phenyl radicals, and [Z] is a linear polyhydroxyalkyl radical whose alkyl chain is substituted by at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated, derivatives of said radical.
[Z] is preferably obtained by reductive amination of a reduced sugar, e.g., glucose, fructose, maltose, lactose, galactose, mannose, or xylose. The N-alkoxy-or N-aryloxy-substituted compounds may then be converted to the desired polyhydroxy fatty acid amides, for example, in accordance with the teaching of International Patent Application WO-A-95/07331 by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst.
Besides the nonionic surfactants, it is of course also possible for other substances from the group of the ionic surfactants, for example, the anionic or cationic surfactants, to be present in the detergent tablets of the invention.

' CA 02314035 2000-07-13 Detergent tablets which are preferred in the context of the present invention have total surfactant contents of less than 5% by weight, preferably less than 4~ by weight, with particular preference less than 3% by weight, and in particular less than 2% by weight, based in each case on the tablet.
Among the compounds used as bleaches which yield Hz02 in water, particular importance is possessed by sodium percarbonate and sodium perborate monohydrate. Further bleaches which may be used are, for example, sodium perborate tetrahydrate, peroxypyrophosphates, citrate perhydrates, and H202-donating peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or diper-dodecanedioic acid. Cleaning products of the invention may also comprise bleaches from the group of organic bleaches. Typical organic bleaches are the diacyl peroxides, such as dibenzoyl peroxide, for example.
Further typical organic bleaches are the peroxy acids, particular examples being the alkyl peroxy acids and the aryl peroxy acids. Preferred representatives are (a) peroxybenzoic acid and its ring-substituted derivatives, such as alkylperoxybenzoic acids, and also peroxy-a-naphthoic acid and magnesium monoperphthalate, (b) the aliphatic or substituted aliphatic peroxy acids, such as peroxylauric acid, peroxystearic acid, s-phthalimidoperoxycaproic acid [phthaloiminoperoxy-hexanoic acid (PAP)], o-carboxybenzamidoperoxycaproic acid, N-nonenylamidoperadipic acid and N-nonenylamido-persuccinates, and (c) aliphatic and araliphatic peroxy dicarboxylic acids, such as 1,12-diperoxydecane-dicarboxylic acid, 1,9-diperoxyazelaic acid, diperoxy-sebacic acid, diperoxybrassylic acid, the diperoxy-phthalic acids, 2-decyldiperoxybutane-1,4-dioic acid and N,N-terephthaloyldi(6-aminopercaproic acid) may be used.

' CA 02314035 2000-07-13 Bleaches in the detergent tablets of the invention for machine dishwashing may also be substances which release chlorine or bromine. Among suitable chlorine-or bromine-releasing materials, examples include heterocyclic N-bromoamides and N-chloroamides, examples being trichloroisocyanuric acid, tribromoisocyanuric acid, dibromoisocyanuric acid and/or dichloro-isocyanuric acid (DICA) and/or salts thereof with cations such as potassium and sodium. Hydantoin compounds, such as 1,3-dichloro-5,5-dimethylhydantoin, are likewise suitable.
The bleaches are used in machine dishwashing compositions usually in amounts of from 1 to 30% by weight, preferably from 2.5 to 20% by weight, and in particular from 5 to 15% by weight, based in each case on the composition. Detergent tablets which are preferred in the context of the present invention contain bleaches from the group of the oxygen or halogen bleaches, especially the chlorine bleaches, with particular preference sodium perborate and sodium percarbonate, in amounts of from 2 to 25% by weight, preferably from 5 to 20% by weight, and in particular from 10 to 15% by weight, based in each case on the tablet.
Bleach activators, which boost the action of the bleaches, may likewise be a constituent of the detergent tablets of the invention. Known bleach activators are compounds containing one or more N-acyl and/or O-acyl groups, such as substances from the class of the anhydrides, esters, imides and acylated imidazoles or oximes. Examples are tetra-acetylethylenediamine TAED, tetraacetylmethylene-diamine TAMD, and tetraacetylhexylenediamine TAHD, and also pentaacetylglucose PAG, 1,5-diacetyl-2,2-dioxohexahydro-1,3,5-triazine DADHT, and isatoic anhydride ISA.
Bleach activators which may be used are compounds which under perhydrolysis conditions give rise to aliphatic peroxo carboxylic acids having preferably 1 to 10 carbon atoms, in particular 2 to 4 carbon atoms, and/or substituted or unsubstituted perbenzoic acid. Suitable substances are those which carry O-acyl and/or N-acyl groups of the stated number of carbon atoms, and/or substituted or unsubstituted benzoyl groups. Preference is given to polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), acylated triazine derivatives, especially 1,5-diacetyl-2,4-dioxohexa-hydro-1,3,5-triazine (DADHT), acylated glycolurils, especially tetraacetylglycoluril (TAGU), N-acyl imides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides, especially phthalic anhydride, acylated polyhydric alcohols, especially triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydro-furan, N-methylmorpholiniumacetonitrile methyl sulfate (MMA), and the enol esters known from German Patent Applications DE 196 16 693 and DE 196 16 767, and also acetylated sorbitol and mannitol and/or mixtures thereof (SORMAN), acylated sugar derivatives, especially pentaacetylglucose (PAG), pentaacetyl-fructose, tetraacetylxylose and octaacetyllactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example, N-benzoylcaprolactam. Hydrophilically substituted acylacetals and acyllactams are likewise used with preference. Combinations of conventional bleach activators may also be used. The bleach activators are used in machine dishwashing compositions usually in amounts of from 0.1 to 20% by weight, preferably from 0.25 to 15% by weight, and in particular from 1 to 10%

by weight, based in each case on the composition. In the context of the present invention, the stated proportions relate to the weight of the base tablet.
In addition to the conventional bleach activators, or instead of them, it is also possible to incorporate what are known as bleaching catalysts into the base tablets. These substances are bleach-boosting transition metal salts or transition metal complexes such as, for example, Mn-, Fe-, Co-, Ru- or Mo-salen complexes or -carbonyl complexes. Other bleaching catalysts which can be used include Mn, Fe, Co, Ru, Mo, Ti, V and Cu complexes with N-containing tripod ligands, and also Co-, Fe-, Cu- and Ru-ammine complexes.
Preference is given to the use of bleach activators from the group of polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), N-acyl imides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), N-methylmorpholiniumacetonitrile methyl sulfate (MMA), preferably in amounts of up to 10% by weight, in particular from 0.1% by weight to 8% by weight, more particularly from 2 to 8% by weight, and with particular preference from 2 to 6% by weight, based on the overall composition.
Bleach-boosting transition metal complexes, especially those with the central atoms Mn, Fe, Co, Cu, Mo, V, Ti and/or Ru, preferably selected from the group of manganese and/or cobalt salts and/or complexes, with particular preference from cobalt ammine complexes, cobalt acetato complexes, cobalt carbonyl complexes, the chlorides of cobalt or manganese, and manganese sulfate, are used in customary amounts, preferably in an amount of up to 5% by weight, in particular from 0.0025% by weight to 1% by weight, and with particular preference from 0.01% by weight to 0.25% by weight, based in each case on the overall composition. In specific cases, however, it is also possible to use a greater amount of bleach activator.
Preferred detergent tablets contain bleach activators from the groups of polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), N-acyl imides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), and N-methylmorpholiniumacetonitrile methyl sulfate (MMA), in amounts of from 0.25 to 15% by weight, preferably from 0.5 to 10% by weight, and in particular from 1 to 5% by weight, based in each case on the tablet.
The detergent tablets of the invention may include corrosion inhibitors for protecting the ware or the machine, with special importance in the field of machine dishwashing being possessed, in particular, by silver protectants. The known substances of the prior art may be used. In general it is possible to use, in particular, silver protectants selected from the group consisting of triazoles, benzotriazoles, bisbenzo-triazoles, aminotriazoles, alkylaminotriazoles, and transition metal salts or transition metal complexes.
Particular preference is given to the use of benzotriazole and/or alkylaminotriazole. Frequently encountered in cleaning formulations, furthermore, are agents containing active chlorine, which may significantly reduce corrosion of the silver surface.
In chlorine-free cleaners, use is made in particular of oxygen-containing and nitrogen-containing organic redox-active compounds, such as divalent and trivalent phenols, e.g. hydroquinone, pyrocatechol, hydroxyhydroquinone, gallic acid, phloroglucinol, pyrogallol, and derivatives of these classes of ' CA 02314035 2000-07-13 compound. Inorganic compounds in the form of salts and complexes, such as salts of the metals Mn, Ti, Zr, Hf, V, Co and Ce, also find frequent application.
Preference is given in this context to the transition metal salts selected from the group consisting of manganese and/or cobalt salts and/or complexes, with particular preference cobalt ammine complexes, cobalt acetato complexes, cobalt carbonyl complexes, the chlorides of cobalt or of manganese and manganese sulfate. Similarly, zinc compounds may be used to prevent corrosion on the ware.
Preferred detergent tablets contain silver protectants from the group of the triazoles, benzotriazoles, bisbenzotriazoles, aminotriazoles, alkylaminotriazoles and transition metal salts or transition metal complexes, with particular preference benzotriazole and/or alkylaminotriazole, in amounts of from 0.01 to 5% by weight, preferably from 0.05 to 4% by weight, and in particular from 0.5 to 3% by weight, based in each case on the tablet.
Of course, the tablets of the invention may comprise enzymes. The enzymes for optional use in the detergent tablets of the invention are preferably commercially customary solid enzyme preparations.
Suitable enzymes include in particular those from the classes of the hydrolases such as the proteases, esterases, lipases or lipolytic enzymes, amylases, glycosyl hydrolases, and mixtures of said enzymes. All of these hydrolases contribute to removing stains, such as proteinaceous, fatty or starchy marks. For bleaching, it is also possible to use oxidoreductases.
Especially suitable enzymatic active substances are those obtained from bacterial strains or fungi such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Coprinus cinereus and Humicola insolens, and also from genetically modified variants thereof.
Preference is given to the use of proteases of the subtilisin type, and especially to proteases obtained from Bacillus lentus. Of particular interest in this context are enzyme mixtures, examples being those of protease and amylase or protease and lipase or lipolytic enzymes, or of protease, amylase and lipase or lipolytic enzymes, or protease, lipase or lipolytic enzymes, but especially protease and/or lipase-containing mixtures or mixtures with lipolytic enzymes.
Examples of such lipolytic enzymes are the known cutinases. Peroxidases or oxidases have also proven suitable in some cases. The suitable amylases include, in particular, alpha-amylases, iso-amylases, pullulanases, and pectinases.
The enzymes may be adsorbed on carrier substances or embedded in coating substances in order to protect them against premature decomposition. The proportion of the enzymes, enzyme mixtures or enzyme granules may be, for example, from about 0.1 to 5% by weight, preferably from 0.5 to about 4.5% by weight. Detergent tablets which are preferred in the context of the present invention are those which comprise protease and/or amylase.
Dyes and fragrances may be added to the detergent tablets of the invention in order to enhance the esthetic appeal of the products which are formed and to provide the consumer with not only the performance but also a visually and sensorially "typical and unmistakeable" product. As perfume oils and/or fragrances it is possible to use individual odorant compounds, examples being the synthetic products of the ester, ether, aldehyde, ketone, alcohol, and hydrocarbon types. Odorant compounds of the ester type are, for example, benzyl acetate, phenoxyethyl isobutyrate, p-tert-butylcyclohexyl acetate, linalyl ' - 33 -acetate, dimethylbenzylcarbinyl acetate, phenylethyl acetate, linalyl benzoate, benzyl formate, ethyl methylphenylglycinate, allyl cyclohexylpropionate, styrallyl propionate, and benzyl salicylate. The ethers include, for example, benzyl ethyl ether; the aldehydes include, for example, the linear alkanals having 8-18 carbon atoms, citral, citronellal, citronellyloxy-acetaldehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal; the ketones include, for example, the ionones, a-isomethylionone and methyl cedryl ketone; the alcohols include anethole, citronellol, eugenol, geraniol, linalool, phenylethyl alcohol, and terpineol; the hydrocarbons include primarily the terpenes such as limonenes and pinene.
Preference, however, is given to the use of mixtures of different odorants, which together produce an appealing fragrance note. Such perfume oils may also contain natural odorant mixtures, as obtainable from plant sources, examples being pine oil, citrus oil, jasmine oil, patchouli oil, rose oil or ylang-ylang oil.
Likewise suitable are clary sage oil, camomile oil, clove oil, balm oil, mint oil, cinnamon leaf oil, lime blossom oil, juniperberry oil, vetiver oil, olibanum oil, galbanum oil and labdanum oil, and also orange blossom oil, neroliol, orange peel oil, and sandalwood oil.
The fragrances may be incorporated directly into the detergents of the invention; alternatively, it may be advantageous to apply the fragrances to carriers.
In order to enhance the esthetic appeal of the composition of the invention, it (or parts thereof) may be colored with appropriate dyes. Preferred dyes, whose selection presents no difficulty whatsoever to the skilled worker, possess a high level of storage stability and insensitivity to the other ingredients of the compositions and to light and possess no pronounced affinity for the substrates to be treated with the compositions, such as glass, ceramic, or plastic tableware, so as not to stain them.
Detergent tablets which are preferred in the context of the present invention further contain one or more substances from the groups of the enzymes, corrosion inhibitors, scale inhibitors, cobuilders, dyes and/or fragrances in total amounts of from 6 to 30% by weight, preferably from 7.5 to 25% by weight, and in particular from 10 to 20% by weight, based in each case on the tablet weight.
The above remarks have been based on a tablet, the present invention not being restricted to the provision of only single-phase tablets. Rather, it is also possible for just individual phases, preferably layers, to have a composition in accordance with the invention and for the stated advantages to be achieved in this way. It is possible in this way, for example, to prepare a two-layer tablet one of whose layers contains - based on the layer - from 0.1 to 9% by weight of zeolite and from 20 to 95% by weight of phosphates) while the other layer may be free from zeolite and/or phosphate. In this way, the dissolution of one layer may be accelerated in time relative to another layer.
Of course, the subregion of the tablet that has the composition according to the invention is not tied to the layer. Rather, the phase of the tablet which contains - based on the phase - from 0.1 to 9% by weight of zeolite and from 20 to 95% by weight of phosphates) may also possess the form of rings, cores, coatings, beads, etc. In this way it is possible to produce ring-core tablets, laminated tablets, inlay tablets, etc . , in which all the phases or only some of the phases have the composition according to the invention and, accordingly, dissolve more rapidly.

The production of the detergent tablets of the invention, accordingly, is not restricted to the compression simply of one particulate premix to form a tablet. Instead, the tablet may also be designed in such a way that multilayer tablets are produced conventionally by preparing two or more premixes which are compressed with one another. In this case, the premix which is introduced first is not precompressed or only gently precompressed, in order to acquire a smooth top face which extends parallel to the bottom of the tablet, and final compression to form the finished tablet takes place after the second premix has been introduced. In the case of tablets with three or more layers there is a further, optional precompression following the addition of each premix, before the tablet undergoes final compression after the last premix has been added.
Owing to the increasing technical effort involved, preference is given in practice to tablets having a maximum of two layers; i.e., preferred detergent tablets are those which constitute a two-layer tablet.
Even with this intermediate step in the process of the invention, advantages may be achieved from the division of certain ingredients between the individual layers.
For example, preference is given to detergent tablets wherein one layer comprises one or more bleaches and the other layer comprises one or more enzymes. It is not only this separation of bleaches and enzymes which may bring advantages; in addition, the separation of bleaches and bleach activators for optional use may be advantageous, so that preference is given to detergent tablets of the invention wherein one layer comprises one or more bleaches and the other comprises one or more bleach activators.

In the remarks below relating to the further subject matter of the present invention, the production of a subregion of the tablet of corresponding composition is included, even if not mentioned explicitly in each case.
The present invention further provides a process for producing detergent tablets by conventionally compressing a particulate premix, wherein said premix contains phosphates) in amounts of from 20 to 95% by weight and a finely divided auxiliary having an average particle size of less than 100 Vim, preferably less than 40 ~,m, with particular preference less than 20 Vim, and in particular less than 10 Vim, in amounts of from 0.1 to 9% by weight.
The above remarks relating to preferred properties of the auxiliaries used in accordance with the invention (solubility in water, amount, type etc.) apply completely analogously to the process of the invention.
Particular preference is given, again, to the use of zeolite, so that in preferred processes the premix contains zeolite in amounts of from 0.1 to 9% by weight.
In analogy to the remarks made above in respect of the tablets of the invention, the preferred embodiments specified therein (amounts of further ingredients, substances used, physical parameters, etc.) are also preferred in the case of the process of the invention.
As described above in the remarks relating to the tablet, the premix may be composed of a very wide variety of substances. Depending on the composition of the premixes for compression, physical parameters of the premixes may be chosen so as to give advantageous tablet properties.

For instance, in preferred variants of the first process of the invention, the particulate premix has a bulk density of more than 600 g/1, preferably more than 700 g/1, and in particular more than 800 g/1.
In addition, the particle size in the premixes intended for compression may be established in order to obtain advantageous tablet properties. In preferred variants of the process of the invention, the particulate premix has a particle size distribution in which less than 10%
by weight, preferably less than 7.55 by weight, and in particular less than 5% by weight, of the particles are greater than 1600 ~,m or smaller than 200 ~,m. Narrower particle size distributions are further preferred in this context. In particularly advantageous process variants, the particulate premix has a particle size distribution in which more than 30% by weight, preferably more than 40% by weight, and in particular more than 50% by weight, of the particles have a size of between 600 and 1000 ~,m.
In connection with its implementation, the process of the invention is not restricted to compressing only one particulate premix to form a tablet. Rather, the process may also be extended to the effect that, in a manner known per se, multilayer tablets are produced by preparing two or more premixes which are compressed one atop another. In this case, the first premix introduced is slightly precompressed in order to acquire a smooth top face which extends parallel to the tablet base, and, after the second premix has been introduced, final compression takes place to form the finished tablet. In the case of tablets with three or more layers there is a further, optional precompression following the addition of each premix before the tablet, after the addition of the last premix, undergoes final compression.

In analogy to the remarks above, preference is given with this process variant as well to processes wherein two-layer tablets are produced by compressing two different particulate premixes onto one another, one of which comprises one or more bleaches and the other of which comprises one or more enzymes. Again, analogously, preferred processes are likewise those wherein two-layer tablets are prepared by compressing two different particulate premixes atop one another, of which one comprises one or more bleaches and the other comprises one or more bleach activators. Here as well, preference is given to processes wherein the tablet produced comprises protease and/or amylase.
The tablets of the invention are produced, as described in principle above, first of all by dry-mixing the constituents, some or all of which may have been pregranulated, and subsequently shaping the dry mixture, in particular by compression to tablets, in which context it is possible to have recourse to conventional processes. To produce the tablets of the invention, the premix (or premixes in the case of multiphase tablets) is compacted in a so-called die between two punches to form a solid compact. This operation, which is referred to below for short as tableting, is divided into four sections: metering, compaction (elastic deformation), plastic deformation, and ejection.
First of all, the premix is introduced into the die, the fill level and thus the weight and form of the resulting tablet being determined by the position of the lower punch and by the form of the compression tool. Even in the case of high tablet throughputs, constant metering is preferably achieved by volumetric metering of the premix. In the subsequent course of tableting, the upper punch contacts the premix and is lowered further in the direction of the lower punch. In the course of this compaction the particles of the premix are pressed closer to one another, with a continual reduction in the void volume within the filling between the punches. When the upper punch reaches a certain position (and thus when a certain pressure is acting on the premix), plastic deformation begins, in which the particles coalesce and the tablet is formed. Depending on the physical properties of the premix, a portion of the premix particles is also crushed and at even higher pressures there is sintering of the premix. With an increasing compression rate, i.e., high throughputs, the phase of elastic deformation becomes shorter and shorter, with the result that the tablets formed may have larger or smaller voids. In the final step of tableting, the finished tablet is ejected from the die by the lower punch and conveyed away by means of downstream transport means. At this point in time, it is only the weight of the tablet which has been ultimately defined, since the compacts may still change their form and size as a result of physical processes (elastic relaxation, crystallographic effects, cooling, etc).
Tableting takes place in commercially customary tableting presses, which may in principle be equipped with single or double punches. In the latter case, pressure is built up not only using the upper punch;
the lower punch as well moves toward the upper punch during the compression operation, while the upper punch presses downward. For small production volumes it is preferred to use eccentric tableting presses, in which the punch or punches is or are attached to an eccentric disk, which in turn is mounted on an axle having a defined speed of rotation. The movement of these compression punches is comparable with the way in which a customary four-stroke engine works. Compression can take place with one upper and one lower punch, or else a plurality of punches may be attached to one eccentric disk, the number of die bores being increased correspondingly. The throughputs of eccentric presses vary, depending on model, from several hundred up to a maximum of 3000 tablets per hour.
For greater throughputs, the apparatus chosen comprises rotary tableting presses, in which a relatively large number of dies is arranged in a circle on a so-called die table. Depending on model, the number of dies varies between 6 and 55, larger dies also being obtainable commercially. Each die on the die table is allocated an upper punch and a lower punch, it being possible again for the compressive pressure to be built up actively by the upper punch or lower punch only or else by both punches. The die table and the punches move around a common, vertical axis, and during rotation the punches, by means of raillike cam tracks, are brought into the positions for filling, compaction, plastic deformation, and ejection. At those sites where considerable raising or lowering of the punches is necessary (filling, compaction, ejection), these cam tracks are assisted by additional low-pressure sections, low tension rails, and discharge tracks. The die is filled by way of a rigid supply means, known as the filling shoe, which is connected to a stock vessel for the premix. The compressive pressure on the premix can be adjusted individually for upper punch and lower punch by way of the compression paths, the buildup of pressure taking place by the rolling movement of the punch shaft heads past displaceable pressure rolls.
In order to increase the throughput, rotary presses may also be provided with two filling shoes, in which case only one half-circle need be traveled to produce one tablet. For the production of two-layer and multilayer tablets, a plurality of filling shoes are arranged in series, and the gently pressed first layer is not ejected before further filling. By means of an appropriate process regime it is possible in this way to produce laminated tablets and inlay tablets as well, having a construction like that of an onion skin, where in the case of the inlay tablets the top face of the core or of the core layers is not covered and therefore remains visible. Rotary tableting presses can also be equipped with single or multiple tools, so that, for example, an outer circle with 50 bores and an inner circle with 35 bores can be used simultaneously for compresssion. The throughputs of modern rotary tableting presses amount to more than a million tablets per hour.
When tableting with rotary presses it has been found advantageous to perform tableting with minimal fluctuations in tablet weight. Fluctuations in tablet hardness can also be reduced in this way. Slight fluctuations in weight can be achieved as follows:
- use of plastic inserts with small thickness tolerances - low rotor speed - large filling shoes - harmonization between the filling shoe wing rotary speed and the speed of the rotor -filling shoe with constant powder height - decoupling of filling shoe and powder charge To reduce caking on the punches, all of the antiadhesion coatings known from the art are available.
Polymer coatings, plastic inserts or plastic punches are particularly advantageous. Rotating punches have also been found advantageous, in which case, where possible, upper punch and lower punch should be of rotatable configuration. In the case of rotating punches, it is generally possible to do without a plastic insert. In this case the punch surfaces should be electropolished.

It has also been found that long compression times are advantageous. These times can be established using pressure rails, a plurality of pressure rolls, or low rotor speeds. Since the fluctuations in tablet hardness are caused by the fluctuations in the compressive forces, systems should be employed which limit the compressive force. In this case it is possible to use elastic punches, pneumatic compensators, or sprung elements in the force path. In addition, the pressure roll may be of sprung design.
Tableting machines suitable in the context of the present invention are obtainable, for example, from the following companies: Apparatebau Holzwarth GbR, Asperg, Wilhelm Fette GmbH, Schwarzenbek, Hofer GmbH, Weil, Horn & Noack Pharmatechnik GmbH, Worms, IMA
Verpackungssysteme GmbH, Viersen, KILIAN, Cologne, KOMAGE, Kell am See, KORSCH Pressen AG, Berlin, and Romaco GmbH, Worms. Examples of further suppliers are Dr. Herbert Pete, Vienna (AU), Mapag Maschinenbau AG, Berne (CH), BWI Manesty, Liverpool (GB), I. Holland Ltd., Nottingham (GB), Courtoy N.V., Halle (BE/LU), and Medicopharm, Kamnik (SI). A particularly suitable apparatus is, for example, the hydraulic double-pressure press HPF 630 from LAEIS, D. Tableting tools are obtainable, for example, from the following companies: Adams Tablettierwerkzeuge, Dresden, Wilhelm Fett GmbH, Schwarzenbek, Klaus Hammer, Solingen, Herber & Sohne GmbH, Hamburg, Hofer GmbH, Weil, Horn & Noack, Pharmatechnik GmbH, Worms, Ritter Pharmatechnik GmbH, Hamburg, Romaco GmbH, Worms, and Notter Werkzeugbau, Tamm. Further suppliers are, for example, Senss AG, Reinach (CH) and Medicopharm, Kamnik (SI).
The tablets can be produced in predetermined three-dimensional forms and predetermined sizes. Suitable three-dimensional forms are virtually any practicable designs - i.e., for example, bar, rod or ingot form, ' - 43 -cubes, blocks and corresponding three-dimensional elements having planar side faces, and in particular cylindrical designs with a circular or oval cross section. This latter design covers forms ranging from tablets through to compact cylinders having a height-to-diameter ratio of more than 1.
The portioned compacts may in each case be formed as separate, individual elements corresponding to the predetermined dosage of the detergents. It is equally possible, however, to design compacts which combine a plurality of such mass units in one compact, with the ease of separation of smaller, portioned units being provided for in particular by means of predetermined breakage points. For the use of textile detergents in machines of the type customary in Europe, with a horizontally arranged mechanism, it may be judicious to design the portioned compacts as cylindrical or block-shaped tablets, preference being given to a diameter/
high ratio in the range from about 0.5 . 2 to 2 . 0.5.
Commercially customary hydraulic presses, excentric presses and rotary presses are suitable equipment in particular for producing such compacts.
Another preferred tablet which can be produced has a platelike or barlike structure with, in alternation, long, thick and short, thin segments, so that individual segments can be broken off from this "slab"
at the predetermined breaking points, represented by the short, thin segments, and inserted into the machine. This principle of the "slablike" tablet detergent may also be realized in other geometric forms; for example, vertical triangles connected to one another lengthwise at only one of their sides.
However, it is also possible for the various components not to be compressed to a homogeneous tablet, but instead for tablets to be obtained which have a plurality of layers, i.e., at least two layers. In this case it is also possible for these different layers to have different dissolution rates. This may result in advantageous performance properties for the tablets.
If, for example, there are components present in the tablets which have adverse effects on each other, then it is possible to integrate one component into the quicker-dissolving layer and the other component into a slower-dissolving layer, so that the first component has already reacted when the second passes into solution. The layer structure of the tablets may be realized in stack form, in which case dissolution of the inner layers) at the edges of the tablet takes place at a point when the outer layers have not yet fully dissolved; alternatively, the inner layers) may also be completely enveloped by the respective outerlying layer(s), which prevents premature dissolution of constituents of the inner layer(s).
In one further-preferred embodiment of the invention, a tablet consists of at least three layers, i.e., two outer and at least one inner layer, with at least one of the inner layers comprising a peroxy bleach, while in the stack-form tablet the two outer layers, and in the case of the envelope-form tablet the outermost layers, are free from peroxy bleach. Furthermore, it is also possible to provide for spatial separation of peroxy bleach and any bleach activators and/or enzymes present in one tablet.
Similar effects can also be achieved by coating individual constituents of the detergent composition intended for compression, or of the tablet as a whole.
For this purpose the elements to be coated may be sprayed, for example, with aqueous solutions or emulsions, or else a coating may be obtained by the technique of melt coating.

After compression, the detergent tablets possess high stability. The fracture strength of cylindrical tablets can be gaged by way of the parameter of diametral fracture stress. This diametral fracture stress can be determined by ~Dt where a represents the diametral fracture stress (DFS) in Pa, P is the force in N which leads to the pressure exerted on the tablet, which pressure causes the fracture of the tablet, D is the tablet diameter in meters, and t is the tablet height.
The present invention further provides for the use of preferably water-insoluble substances having average particle sizes of less than 100 Vim, preferably less than 40 Vim, with particular preference less than 20 Vim, and in particular less than 10 ~,m, as disintegration aids in phosphate-containing detergent tablets.
In the context of the use in accordance with the invention as well, the embodiments given as preferred above for the detergent tablets of the invention and for the process of the invention are also preferred.
The present invention therefore preferably provides for the use of zeolite as a disintegration aid in phosphate-containing detergent tablets. This use of zeolite in accordance with the invention leads to tablets having advantageous properties as shown by the examples below. As far as preferred embodiments of the use in accordance with the invention are concerned (particle sizes, further ingredients, composition of the premix, etc.), the comments made above for the process of the invention apply analogously. One particularly preferred embodiment provides for the use of zeolites in amounts of from 1 to 9~ by weight as disintegration aids in detergent tablets having phosphate contents of between 10 and 95% by weight.
Examples:
By compressing two different premixes, two-layer rectangular tablets were produced consisting of 68% by weight of bottom phase and 32% by weight of top phase.
The composition of the top phase was firstly designed in accordance with the invention (tablet E); in the comparative tablets, V, zeolite was not used and instead only phosphate was used. The composition of the bottom phase was identical for both tablets E and V.
The composition (in % by weight, based on the respective premix) of the three premixes and thus of the two different two-phase tablets is shown in the following table:
Premix 1 Premix 2 Premix 3 (bottom phase(top phase (top phase S and V) V) E) Sodium carbonate 32.0 - -Sodium 52.0 91.4 88.7 tripolyphosphate Zeolite A - - 2.7 Sodium perborate 10.0 - -Tetraacetylethylene-2.5 - -diamine Benzotriazole 1.0 - -fatty alcohol 2.5 - -containing 3 EO

Dye 0.2 0.2 Enzyme 6.0 6.0 Perfume 0.4 0.4 Silicone oil I 2.0 I 2.0 The disintegration rate and solubility of the tablets is determined in a glass beaker apparatus. A tablet weighing 20 g in a weighed basket was held in a glass beaker containing one liter of water at 50°C in which a propellor stirrer rotated at 800 revolutions per minute. Because the basket was weighed, the disintegration rate is given by the loss in mass. The solubility was determined by means of conductivity measurement, the conductivity value after 40 minutes being defined as 100% and the values determined being standardized therewith.
The results of these investigations are shown in the table below, in which the solubility figures are collated in % (of the final conductivity) and the disintegration figures in g (amount already disintegrated).
Time 8 (Premix V (Premix [mini 1 + 3) 1 + 2) Solubility Disintegration SolubilityDisintegration 4 0 10 0 I --i o O - ~ - 10 10 0 The table shows that the tablets E of the invention, in which the top phase has a composition according to the 20 invention, disintegrate more rapidly and dissolve more effectively. Whereas the tablets E of the invention have fallen completely through the basket (i.e., have disintegrated) and dissolved after just 20 minutes, the comparative tablets require 25 minutes for 25 disintegration and have dissolved completely only after 30 minutes.

Claims (49)

1. A detergent tablet comprising builders and bleaches and, optionally, further customary detergent ingredients, wherein the phosphate content is from 20 to 95% by weight and the tablet further comprises from 0.1 to 9% by weight of a finely divided auxiliary having an average particle size of less than 100 µm.

2. The tablet as claimed in claim 1, wherein the finely divided auxiliary has an average particle size of less than 40 µm.

3. The tablet as claimed in claim 2, wherein the particle size is less than 20 µm.

4. The tablet as claimed in claim 2, wherein the particle size is less than 10 µm.

5. The tablet as claimed in any of claims 1 to 4, wherein the finely divided auxiliary is essentially water-insoluble.

6. The tablet as claimed in any of claims 1 to 5, comprising zeolite as finely divided auxiliary.

7. The tablet as claimed in any of claims 1 to 6, comprising, based in each case on the tablet, from 0.25 to 7.5% by weight of zeolite.

8. The tablet as claimed in claim 7, wherein the zeolite comprises from 0.5 to 5% by weight.

9. The tablet as claimed in claim 7 and 8, wherein the zeolite comprises from 1 to 3% by weight of zeolite.

10. The tablet as claimed in claim 7, 8 or 9, wherein the zeolite is X, Y and/or P.

11. The tablet as claimed in any of claims 1 to 10, wherein the phosphate content is from 30 to 92.5%
by weight based on the tablet.

12. The tablet as claimed in claim 11, wherein the content is from 40 to 90% by weight.

13. The tablet as claimed in claim 11 or 12, wherein the content is from 50 to 85% by weight.

14. The tablet as claimed in any of claims 1 to 13, wherein the total surfactant content is less than 5% by weight based on the tablet.

15. The tablet as claimed in claim 14, wherein the content is less than 4% by weight.

16. The tablet as claimed in claim 14 or 15, wherein the content is less than 3% by weight.

17. The tablet as claimed in claim 14, 15 or 16, wherein the content is less than 2% by weight.

18. The tablet as claimed in any of claims 1 to 17, which contains bleaches from the group of the oxygen or halogen bleaches, in amounts of from 2 to 25% by weight, based on the tablet.

19. The tablet as claimed in claim 18, wherein the bleach is a chlorine.

20. The tablet as claimed in claim 18 or 19, wherein the bleach is sodium perborate or sodium percarbonate.

21. The tablet as claimed in any of claims 18 to 20, wherein the amount is from 5 to 20% by weight.

22. The tablet as claimed in any of claims 18 to 21, wherein the amount is from 10 to 15% by weight.

23. The tablet as claimed in any of claims 1 to 22, which contains bleach activators from the groups of polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), N-acylimides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS) and N-methylmorpholiniumacetonitrile methyl sulfate (MMA), in amounts of from 0.25 to 15% by weight, based on the tablet.

24. The tablet as claimed in claim 23, wherein the amounts are from 0.5 to 10% by weight.

25. The tablet as claimed in claim 23 or 24, wherein the amounts are from 1 to 5% by weight,

26. The tablet as claimed in any of claims 1 to 25, which contains silver protectants from the group of the' triazoles, benzotriazoles, bisbenzo-triazoles , aminotriazoles, alkylaminotriazoles and transition metal salts or transition metal complexes, in amounts of from 0.01 to 5% by weight, based on the tablet.

27. The tablet as claimed in claim 26 wherein benzotriazole and/or alkylaminotriazole is present.

28. The tablet as claimed in claim 26 or 27, wherein the amounts are from 0.05 to 4% by weight.

29. The tablet as claimed in claim 26, 27 or 28, wherein the amounts are from 0.5 to 3% by weight,

30. The tablet as claimed in any of claims 1 to 29, further containing one or more substances from the groups of the enzymes, corrosion inhibitors, scale inhibitors, cobuilders, dyes and/or fragrances in total amounts of from 6 to 30% by weight, based on the tablet weight.

31. The tablet as claimed in claim 30, wherein the amounts are from 7.5 to 25% by weight.

32. The tablet as claimed in claim 30 or 31, wherein the amounts are from 10 to 20% by weight.

33. A process for producing a detergent tablet by conventionally compressing a particulate premix, wherein said premix contains phosphate(s) in amounts of from 20 to 95% by weight and a finely divided auxiliary having an average particle size of less than 100 µm, in amounts of from 0.1 to 9%
by weight.

34. The process as claimed in claim 33, wherein the size is less than 40 µm.

35. The process as claimed in claim 33 or 34, wherein the size is less than 20 µm.

36. The process as claimed in claim 33, 34 or 35, wherein the size is less than 10 µm.

37. The process as claimed any of in claims 33 to 36, wherein said premix contains zeolite in amounts of from 0.1 to 9% by weight.

38. The process as claimed in any of claims 33 or 37, wherein said particulate premix has a bulk density of more than 600 g/l.

39. The process as claimed in claim 38, wherein the bulk density is more than 700 g/l.

40. The process as claimed in claim 38 or 39, wherein the bulk density is more than 800 g/l.

41. The process as claimed in any of claims 33 to 40, wherein said particulate premix has a particle size distribution in which less than 10% by weight, of the particles are greater than 1600 µm or smaller than 200 µm.

42. The process as claimed in claim 41, wherein the amount is less than 7.5% by weight.

43. The process as claimed in claim 41 or 42, wherein the amount is less than 5% by weight.

44. The process as claimed any of claims 41 to 43, wherein said particulate premix has a particle size distribution in which more than 30% by weight, of the particles have a size of between 600 and 1000 µm.

45. The process as claimed in claim 44, wherein the amount is more than 40% by weight.

46. The process as claimed in claim 44 or 45, wherein the amount is more than 50% by weight.

47. The use of preferably water-insoluble substances having particle sizes of less than 100µm, as disintegration aids in phosphate-containing detergent tablets.

48. The use of zeolites as a disintegration aid in phosphate-containing detergent tablets.

49. The use of zeolites in amounts of from 1 to 9% by weight as disintegration aids in detergent tablets having phosphate contents of between 10 and 95% by weight.