CA2314414A1 - Tabletting punches and a tabletting process - Google Patents

Abstract

Tabletting punches which distinctly reduce caking levels during tabletting and which are suitable in particular for the production of detergent tablets have projections and depressions on their contact surface, the interval between the projections being between 5 and 200 µm and the height of the projections between 5 and 100 µm. By using tabletting punches such as these, tabletting processes can be carried out over long periods without cleaning intervals and without any adverse effects on the individual tablets, irrespective of the particular tablet press used.

Description

TABLETTING PUNCHES AND A TABLETTING PROCESS
Field of the Invention This invention relates to tabletting punches and to a process for the production of shaped bodies, more particularly detergent tablets, using such tabletting punches. More particularly, the invention relates to a process for the production of such shaped bodies in large numbers, the variations in weight of the tablets and the level of caking on the tabletting punches within one and the same series both being minimized.
Background of the Invention The production of shaped bodies, particularly tablets, is now an established part of technical knowledge, particularly in the pharmaceutical industry. Tablets as a supply form have also made a successful entry into other fields by virtue of their predetermined dosage, their compactness and the reduction in packaging, transportation and storage costs attributable to their high densities. Nowadays, many everyday products, such as batteries and teapot warmers, are produced by tabletting technology, detergent tablets for dishwashing machines and laundry detergent tablets for domestic washing being of particular importance.
In the same way as the production of pharmaceutical tablets, the production of detergent tablets is attended by problems relating to the varying weight and hence the varying hardness of several tablets within one and the same series. The dichotomy between hardness and disinte-gration time is a central problem above all for detergent tablets: on the one hand the tablets have to be sufficiently stable to be able to be packed after tabletting, transported to retail outlets and handled by the consumer; on the other hand, to guarantee successful washing and cleaning, the tablet disintegration times have to be extremely short, for example to prevent residues on fabrics or to enable the tablets to be introduced from the dispensing compartment of commercially available washing machines. In large scale production, it is impossible to prevent the tablets produced from differing more or less significantly in their hardness. Since the tablet presses normally used for production (both eccentric and rotary presses) compress to a predetermined level (corresponding to a constant volume), variations in the density of the premix to be tabletted and inaccuracies in the dosage of the premix lead to variations in the weight of final tablets which can be additionally increased by adhesion of the premixes to be tabletted to the tabletting punches during the tabletting process. Caking on the tabletting punches leads to a loss of weight in individual tablets and, in addition, has the effect that the tablets produced do not have any flat surfaces. Accordingly, the tabletting punches normally have to be cleaned at short time intervals during each tabletting process.
In tabletting technology, such problems are solved by specially optimized formulations or by the use of mold release agents. On the machinery side, it is recommended to provide the punches with plastic inserts or to use machines which enable the punches to rotate.
Unfortunately, all the solutions mentioned have only been partly successful.
Now, the problem addressed by the present invention was to provide tabletting punches which would distinctly reduce the problem of caking during the tabletting process. For the production of detergent tablets in particular, the invention sought to provide a process which, irrespective of the tablet press used, would enable tabletting to be carried out over long periods without any cleaning intervals and without any adverse effects on the individual tablets.
Summary of the Invention According to the invention, the solution to this problem is charac-terized by the use of tabletting punches with a particular surface structure in tabletting processes.
Accordingly, the present invention relates to tabletting punches of which the tabletting surface has projections and depressions, the interval between the projections being between 5 and 200 Nm and the height of the projections being between 5 and 100 pm.
In the tabletting of particulate premixes, the special surface structure of the punch contact surfaces leads to distinctly minimized caking, the nature of the mixture to be tabletted being of secondary importance. The materials of which the punch contact surface or the tabletting punches themselves consist can also be freely selected and may be adapted to meet other requirements, for example in terms of strength, weight, tendency to wear, etc. Preferred surface structures are characterized by projections and depressions with heights and intervals within relatively narrow ranges. Thus, preferred tabletting punches are characterized in that the interval between the projections is from 6 to 180 Nm, preferably from 7 to 160 Nm, more preferably from 8 to 140 Nm and most preferably from 10 to 100 pm. The height of the projections is within similar relatively narrow limits. In preferred tabletting punches, the height of the projections is from 6 to 90 Nm, preferably from 7 to 80 Nm, more preferably from 8 to 70 Nm and most preferably from 10 to 50 pm.
Optimally low caking levels are obtained when the projections of the surface structures are sufficiently close together to avoid contact of the depressions between the regions by particles or ingredients of the premix to be tabletted. If the projections of the surface structures are situated close together or if the depressions are not deep enough, the surface structure again acts like a continuous surface and can be better wetted, so that the tendency towards caking increases. Accordingly, the height of the projections should increase with increasing intervals between the projections.
Detailed Description of the Invention Surface structures of the type in question can be produced in various ways. For example, the contact surface of a tabletting punches can be subjected to one of the following treatment steps to produce the required surface structure. Another possibility is separately to produce parts of the tabletting punch with the required surface structure and then to join them to the rest of the punch. In this connection, reference is made in particular to the production of disks with the required surface structures, the disks being applied to tabletting punches (for example by bonding) after their production and forming the contact surface. The surface structures according to the invention can be obtained independently of the geometry of the contact surface, so that flat contact surfaces that are circular, elliptical, triangular, quadratic, rectangular, square, pentagonal, hexagonal, heptagonal, octagonal and polygonal in shape or even completely irregular in shape, for example in the shape of arrows, plants or animals, can be produced. The surface structure of the contact surfaces according to the invention affords particular advantages in the case of non-flat contact surfaces, particularly those which have such surface structures as milled or raised lettering, symbols, etc. Convex and concave contact surfaces can also be provided in accordance with the invention.
The surface structure according to the invention may be subsequently applied to the punch or produced thereon. The surface structure may be applied, for example, by adhesively applying sufficiently large particles to relatively smooth punch contact surfaces. The adhesive application of particles, more particularly plastic particles, has proved particularly successful in this regard. The surface structures may also be subsequently applied, for example, by the adhesive application of corresponding films or disks. In this case, the film or disk forms the punch contact surface. The production of the surface structures according to the invention on punch surfaces can be carried out, for example, by subsequent scoring, embossing or etching, for which purpose heated embossing elements or rollers may also be used, which has proved particularly successful in the case of thermoformable punch surfaces.
Etching can be carried out, for example, by chemical etching or by physical etching, for example ion etching or sandblasting.

5 In the case of forming/shaping, not only the size of the projections and the intervals between them, but also the shape of the projections can be varied as required. In one particularly preferred embodiment, the projections have rounded tips which, ideally, are hemispherical in shape.
According to the invention, the materials of the punch contact surface may be freely selected and, hence, adapted to meet other requirements. In order to obtain a particularly significant reduction in caking, it has been found to be preferable to make the punch contact surfaces water-repellent. In particularly preferred tabletting punches, the projections at least consist of hydrophobic polymers or durably hydrophobicized materials.
Polyolefins, preferably polyethylene or polypropylene, have proved successful as hydrophobic polymers of which preferably at least the projections consist. Polyethylenes (PEs) are polymers belonging to the polyolefins with groups of the following type:
-[CH2-CH2J-as the characteristic basic unit of the polymer chain. Polyethylenes are produced by polymerization of ethylene by two basically different methods, i.e. the high-pressure method and the low-pressure method. The resulting products are often referred to accordingly as high-pressure polyethylene and low-pressure polyethylene. They differ mainly in their degree of branching and hence in their degree of crystallinity and their density. Both methods may be carried out as solution polymerization, emulsion polymeri-zation or gas phase polymerization.
The high-pressure method gives branched polyethylenes with a low density (ca. 0.915-0.935 g/cm3) and degrees of crystallinity of ca. 40-50%
which are referred to as I_DPE types. Products of relatively high molecular weight and, hence, improved strength and stretchability are referred to in short as HMW-LDPE (HMW = high molecular weight). By copolymerizing ethylene with relatively long-chain olefins, more particularly with butene and octene, the pronounced degree of branching of the polyethylenes produced by the high-pressure method can be reduced; the copolymers are referred to in short as LLD-PE (linear low density polyethylene).
The macromolecules of the polyethylenes from low-pressure processes are substantially linear and unbranched. These polyethylenes (HDPE) have degrees of crystallinity of 60 to 80% and a density of ca.
0.94-0.965 g/cm3. They are particularly suitable as materials for the projections at least, although the entire punch contact surface preferably consists of these materials.
Polypropylenes (PPs) are thermoplastic polymers of propylene with basic units of the following type:
-[CH(CH3)-CH2]-Polypropylenes can be produced by stereospecific polymerization of propylene in the gas phase or in suspension to form highly crystalline isotactic polypropylenes or less crystalline, syndiotactic polypropylenes or amorphous atactic polypropylenes. On an industrial scale, particular signi-ficance attaches to isotactic polypropylene in which all the methyl groups are located on one side of the polymer chain. Polypropylene is distinguish-ed by extreme hardness, resilience, stiffness and heat resistance and, accordingly, is an ideal material for the projections in the context of the present invention.
An improvement in the mechanical properties of the polypropylenes can be achieved by reinforcing them with talcum, chalk, wood meal or glass fibers; metallic coatings may also be applied.
Tabletting punches according to the invention in which the projections at least consist of a polyolefin, preferably polyethylene or polypropylene, are preferred.
According to the invention, other preferred tabletting punches are characterized in that at least the projections consist of polyvinylidene fluoride or polytetrafluoroethylene.
Polyvinylidene fluorides, which are also referred to in short as PVDFs or PVF2s, are polymers obtainable from vinylidene fluoride with the following basic unit:
-[CH2-CF2]-Polyvinylidene fluorides are thermoplastic, readily processable fluoro-plastics which have high resistance to heat and chemicals, but not to the same standard as PTFE. The degree of crystallinity of polyvinylidene fluorides depends upon their previous thermal history: rapid cooling of thin moldings (films) leads to transparent (amorphous) products while slow cooling (or annealing) leads to highly crystalline products.
Polyvinylidene fluorides are distinguished by high mechanical strength, stiffness and toughness (even at low temperatures) and according to the invention are eminently suitable as materials for the projections on the punch contact surfaces or for entire punch contact surfaces or punches.
Polytetrafluoroethylenes are polymers of tetrafluoroethylene with the following basic unit:

-[CF2-CF2]-which are also referred to in short as PTFEs. Another widely used name for such polymers is Teflon, a trademark of Du Pont for polytetrafluoroethylene (PTFE) which was developed in 1938 by R.J.
Plunkett at Du Pont, has been in production since 1941 and has been marketed under the trademark since 1943.
Technical polytetrafluoroethylenes have degrees of polymerization n of ca. 5,000-100,000 which correspond to molecular weights of ca.
500,000-10,000,000 g/mole. The polymerization of the monomers - initi-ated by radical initiators - is carried out in aqueous medium in the absence or presence of stabilizers. In the first case, a dispersion of the polytetra-fluoroethylenes is formed in the initial stage of the polymerization and coagulates as the reaction progresses. Granules are obtained and, after working up, are ground to the required particle size. Where emulsifiers are used in a form of emulsion polymerization, finely powdered polytetrafluoro-ethylene products are obtained as a metastable dispersion which may readily be broken to isolate the polymers. Where ionic surfactants are used as stabilizers, fine-particle stable dispersions with solids contents of 60-65% can also be produced under suitable conditions.
Polytetrafluoroethylenes are thermoelastic polymers with high linearity, a relatively high degree of crystallinity (up to 70%) and a melting point of ca. 327°C at which they become glass-like and transparent.
Poly-tetrafluoroethylenes have extremely high resistance to chemicals and can be used over a very broad temperature range (-200 to 250°C); they are characterized by high thermal stability (maximum long-term service temperature ca. 260°C). Polytetrafluoroethylenes have only a very limited adhesion capacity which, in conjunction with the surface structures according to the invention, makes them ideal materials for punch contact surfaces or for entire punches. For particularly demanding applications where, for example, high creep resistance and low cold flow are required, polytetrafluoroethylenes can be reinforced by incorporation of glass fibers, carbon fibers, carbon black, molybdenum sulfide or polymers, such as polyimides, polyether ketones or polyphenylene sulfides.
Besides the polyolefins and fluoropolymers, polyamides are preferred materials for the projections in the context of the present invention. Polyamides are high molecular weight compounds which consist of units linked by peptide bonds. Apart from a few exceptions, synthetic polyamides (PAs) are thermoplastic, chain-like polymers with recurring acid amide groups in the main chain. From the perspective of their chemical composition, the so-called homopolyamides may be divided into two groups, namely: the aminocarboxylic acid types (AS) and the diamine dicarboxylic acid types (AA-SS), A standing for amino groups and S for carboxy groups. The former are formed from one structural unit by poly-condensation (amino acid) or polymerization (w-lactam) while the latter are formed from two structural units by polycondensation (diamine and dicar-boxylic acid).
The polyamides of unbranched aliphatic structural units are coded according to the number of carbon atoms. Thus, the code PA 6 stands for example for the polyamide synthesized from ~-aminocaproic acid or s-caprolactam while the code PA 12 stands for a poly(s-lauric lactam) of E-lauric lactam. In the case of the AA-SS type, the number of carbon atoms of the diamine comes first, followed by the number of carbon atoms of the dicarboxylic acid: PA 66 (polyhexamethylene adipic amide) is formed from hexamethylenediamine (1,6-hexanediamine) and adipic acid, PA 610 (polyhexamethylene sebacic amide) is formed from 1,6-hexanediamine and sebacic acid while PA 612 (polyhexamethylene dodecane amide) is formed from 1,6-hexanediamine and dodecanedioic acid. According to the invention, the polyamide types mentioned are preferred materials for the projections on the surfaces or for the surfaces themselves. In preferred tabletting punches according to the present invention, at least the projections consist of a polyamide, preferably of PA 6, PA 12, PA 66, PA
5 610 orPA612.
Other preferred materials for the projections are polyurethanes.
Tabletting punches in which at least the projections consist of a polyurethane are also preferred.
Polyurethanes (PURs) are polymers (polyadducts) obtainable by 10 polyaddition from dihydric and higher alcohols and isocyanates which contain groups of the following type:
-[CO-NH-R2-NH-CO-O-R'-O]-as characteristic basic units of the basic macromolecules, in which R' is a low molecular weight or polymeric diol residue and R2 is an aliphatic or aromatic group. Industrially important PUR are produced from polyester and/or polyether diols and, for example, from 2,4- or 2,6-toluene diisocya-nate (TDI, R2 = C6H3-CH3), 4,4'-methylene di(phenyl isocyanate) (MDI, R2 =
CsH4-CHZ-C6H4) or hexamethylene diisocyanate [HMDI, R2 = (CH2)6].
The plastics mentioned above may be used on their own as materials for the projections, although they may also be provided with coatings or laminations of metals or other materials. According to the invention, the use of glass-fiber-reinforced plastics as a material for punch surfaces, to which the structures mentioned are applied, has proved to be particularly successful. Glass-fiber-reinforced plastics (GFPs) are composite materials of a combination of a matrix of polymers and glass fibers acting as a reinforcement. The glass materials used for fiber reinforcement are present in the GFPs as fibers, yarns, rovings, nonwovens, cloths or mats. Suitable polymeric matrix systems for GFPs are both thermosets (such as, for example, epoxy resins, unsaturated polyester resins, phenolic and furan resins) and thermoplastics (such as, for example, polyamides, polycarbonates, polyacetals polyphenylene oxides and sulfides, polypropylenes and styrene copolymers). The ratio by weight of reinforcing material to polymer matrix is normally in the range from 10:90 to 65:35, the strength properties of the GFPs generally increasing up to a reinforcing material content of around 40% by weight.
The GFPs are mainly produced by molding processes; other important production processes are hand lamination, fiber spraying, con tinuous impregnation, winding and centrifugal processes. In many cases, so-called prepregs - glass fiber materials pre-impregnated with resins - are also used as starting materials, being cured by application of heat and pressure. The GFPs are distinguished from the non-reinforced matrix polymers by increased tensile strength, flexural strength and compressive strength, impact strength, dimensional stability and stability to the effects of heat, acids, salts, gases and solvents. According to the invention, glass-fiber-reinforced polytetrafluoroethylene and glass fiber reinforced polyamides have proved particularly successful as materials for the punch contact surfaces or the punches themselves. Accordingly, preferred tabletting punches are characterized in that at least the projections consist of a glass-fiber-reinforced plastic, preferably a glass-fiber-reinforced polytetrafluoroethylene or polyamide.
In the case of the composite materials mentioned, the surface structures can be produced from powders or films of composite material, although entire punches can also be produced from the composite materials and subsequently provided with the surface structure according to the invention (see above).
Other materials, of which at least the projections on the punch contact surfaces of the punches according to the invention, but preferably the entire punch contact surfaces or punches may consist, are for example silicones or silanized hydrophilic surfaces. Metals are also suitable materials of which at least the projections on the punch contact surfaces of the punches according to the invention, but preferably the entire punch contact surfaces or punches may consist. Besides the known steels and stainless steels, titanium and titanium alloys, tantalum and tantalum alloys and tungsten and tungsten alloys in particular have proved to be suitable.
In principle, however, any metals may be used, the materials being chosen with the material to be tabletted in mind.
The present invention also relates to a process for the production of tablets by tabletting a particulate premix, in which the tabletting punches used have projections and depressions on their contact surface, the interval between the projections being between 5 and 200 Nm and the height of the projections being between 5 and 100 pm.
As mentioned at the beginning, distinctly reduced caking levels are obtained irrespective of the physical and chemical properties of the premix.
Accordingly, the process according to the invention may be used with advantage for any tabletting processes, including for example the production of pharmaceutical tablets, the tabletting of battery parts, the production of human and animal foods, the tabletting of candles and other consumer goods and the production of industrial tablets, such as coal briquettes, catalysts in tablet form or the like.
The process according to the invention may be used with particular advantage for the tabletting of "tacky" premixes of the type tabletted, for example, in the production of compact detergent tablets. Accordingly, the present invention also relates to a process in which the particulate premix is a detergent composition and the tablets are detergent tablets.
Tablettable premixes for detergent tablets typically contain surfactant-containing granules of at least one type which are mixed with other detergent ingredients to form the premix to be tabletted which is then tabletted. In preferred processes according to the invention, particulate premixes contain surfactant-containing granules and have a bulk density of at least 500 g/I, preferably of at least 600 g/I and more preferably of at least 700 g/I.
The production of surfactant-containing granules is widely described in the prior art. Besides the traditional granulation and agglomeration processes which may be carried out in various mixer/granulators and mixer/agglomerators, press agglomeration processes for example may also be used.
The granulation process may be carried out in any of a number of machines typically used in the detergent industry. Suitable mixers are both high-shear mixers and also normal mixers with relatively low rotational speeds. Examples of suitable mixers are Series R or RV Eirich~ mixers (trademarks of Maschinenfabrik Gustav Eirich, Hardheim), the Schugi~
Flexomix, the Fukae~ FS-G mixers (trademarks of Fukae Powtech, Kogyo Co., Japan), Lodige~ FM, KM and CB mixers (trademarks of Lodige Maschinenbau GmbH, Paderborn) and Series T or K-T Drais~ mixers (trademarks of Drais-Werke GmbH, Mannheim). The residence times of the granules in the mixers are less than 60 seconds, the residence time also depending on the rotational speed of the mixer. The residence times are shorter, the higher the speed of the mixer. The residence times of the granules in the mixer are preferably less than 1 minute and preferably less than 15 seconds.
In preferred processes according to the invention, the surfactant granules have particle sizes of 200 to 2000 Nm, preferably in the range from 400 to 1800 Nm and more preferably in the range from 600 to 1400 pm.

Besides the active substances (anionic and/or nonionic and/or cationic and/or amphoteric surfactants), the surfactant granules preferably contain carriers which, in one particularly preferred embodiment, emanate from the group of builders. Particularly advantageous processes are characterized in that the surfactant-containing granules contain anionic and/or nonionic surfactants and builders and have total surfactant contents of at least 10% by weight, preferably at least 15% by weight and more preferably at least 20% by weight.
These surface-active substances emanate from the group of anionic, nonionic, zwitterionic or cationic surfactants, anionic surfactants being distinctly preferred for economic reasons and for their performance spectrum.
The anionic surfactants used are, for example, those of the sulfonate and sulfate type. Preferred surfactants of the sulfonate type are C9_~3 alkyl benzenesulfonates, olefin sulfonates, i.e. mixtures of alkene and hydroxy-alkane sulfonates, and the disulfonates obtained, for example, from 02_18 monoolefins with an internal or terminal double bond by sulfonation with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products. Other suitable surfactants of the sulfonate type are the alkane sulfonates obtained from C~2_~$ alkanes, for example by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization. The esters of a-sulfofatty acids (ester sulfonates), for example the a-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow acids, are also suitable.
Other suitable anionic surfactants are sulfonated fatty acid glycerol esters, i.e. the monoesters, diesters and triesters and mixtures thereof which are obtained where production is carried out by esterification of a monoglycerol with 1 to 3 moles of fatty acid or in the transesterification of triglycerides with 0.3 to 2 moles of glycerol. Preferred sulfonated fatty acid glycerol esters are the sulfonation products of saturated C6_zz fatty acids, 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 5 particular, the sodium salts of the sulfuric acid semiesters of C~z_1s fatty alcohols, for example coconut alcohol, tallow alcohol, lauryl, myristyl, cetyl or stearyl alcohol, or Coo-zo 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 10 a synthetic, linear alkyl chain based on a petrochemical and which are similar in their degradation behavior to the corresponding compounds based on oleochemical raw materials. C~z_~6 alkyl sulfates and C~2_~5 alkyl sulfates and also C~4_,5 alkyl sulfates are particularly preferred from the washing performance point of view. Other suitable anionic surfactants are 15 2,3-alkyl sulfates which may be produced, for example, in accordance with US 3,234,258 or US 5,075,041 and which are commercially obtainable as products of the Shell Oil Company under the name of DAN~.
The sulfuric acid monoesters of linear or branched C~_z~ 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~z_~g fatty alcohols containing 1 to 4 EO, are also suitable. In view of their high foaming capacity, they are normally used in only relatively small quantities, for example in quantities of 1 to 5% by weight, in dishwashing detergents.
Other suitable anionic surfactants are the salts of alkyl sulfosuccinic acid which are also known as sulfosuccinates or as sulfosuccinic acid esters and which represent monoesters and/or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and, more particularly, ethoxylated fatty alcohols. Preferred sulfosuccinates contain C8_~$ fatty alcohol molecules or mixtures thereof. Particularly preferred sulfosuccinates contain a fatty alcohol molecule derived from ethoxylated fatty alcohols which, considered in isolation, represent nonionic surfactants (for a description, see below). Of these sulfosuccinates, those of which the fatty alcohol molecules are derived from narrow-range ethoxylated fatty alcohols are particularly preferred. Alk(en)yl succinic acid preferably containing 8 to 18 carbon atoms in the alk(en)yl chain or salts thereof may also be used.
Other suitable anionic surfactants are, in particular, soaps. Suitable soaps are, in particular, saturated fatty acid soaps, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and soap mixtures derived in particular from natural fatty acids, for example coconut, palm kernel or tallow acids.
The anionic surfactants, including the soaps, may be present in the form of their sodium, potassium or ammonium salts and as soluble salts of organic bases, such as mono-, di- or triethanolamine. The anionic surfactants are preferably present in the form of their sodium or potassium salts and, more preferably, in the form of their sodium salts.
According to the invention, preferred processes for the production of detergent tablets are characterized in that the anionic surfactant content of the surfactant granules is between 5 and 45% by weight, preferably between 10 and 40% by weight and more preferably between 15 and 35%
by weight, based on the weight of the surfactant granules.
So far as the choice of the anionic surfactants is concerned, there are no basic conditions to restrict the freedom of formulation. However, preferred surfactant granules have a soap content in excess of 0.2% by weight, based on the total weight of the detergent tablet produced.
Preferred anionic surfactants are the alkyl benzenesulfonates and fatty alcohol sulfates, preferred detergent tablets containing 2 to 20% by weight, preferably 2.5 to 15% by weight and more preferably 5 to 10% by weight of fatty alcohol sulfate(s), based on the weight of the detergent tablets.
Preferred nonionic surfactants are alkoxylated, advantageously ethoxylated, more especially primary alcohols preferably containing 8 to 18 carbon atoms and, on average, 1 to 12 moles of ethylene oxide (EO) per mole of alcohol, in which the alcohol group may be linear or, preferably, methyl-branched in the 2-position or may contain linear and methyl-branched groups in the form of the mixtures typically present in oxoalcohol groups. However, alcohol ethoxylates containing linear groups of alcohols of native origin with 12 to 18 carbon atoms, for example coconut, palm, tallow or oleyl alcohol, and on average 2 to 8 EO per mole of alcohol are particularly preferred. Preferred ethoxylated alcohols include, for example, C~2_~4 alcohols containing 3 EO or 4 EO, C9_» alcohol containing 7 EO, C~3-~5 alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, C~Z_~$ alcohols containing 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of C~2_~4 alcohol containing 3 EO and C12_~$ alcohol containing 5 EO. The degrees of ethoxylation mentioned represent statistical mean values which, for a special product, can be a whole number or a broken number.
Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols containing more than 12 EO may also be used, examples including tallow fatty alcohol containing 14 EO, 25 EO, 30 EO or 40 EO.
Another class of preferred nonionic surfactants which may be used either as sole nonionic surfactant or in combination with other nonionic surfactants are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated, fatty acid alkyl esters preferably containing 1 to 4 carbon atoms in the alkyl chain, more especially the fatty acid methyl esters which are described, for example, in Japanese patent application JP 58/217598 or which are preferably produced by the process described in International patent application WO-A-90113533.
Another class of nonionic surfactants which may advantageously be used are the alkyl polyglycosides (APGs). Suitable alkyl polyglycosides correspond to the general formula RO(G)Z where R is a linear or branched, more particularly 2-methyl-branched, saturated or unsaturated aliphatic radical containing 8 to 22 and preferably 12 to 18 carbon atoms and G
stands for a glycose unit containing 5 or 6 carbon atoms, preferably glucose. The degree of glycosidation z is between 1.0 and 4.0, preferably between 1.0 and 2.0 and more preferably between 1.1 and 1.4.
Linear alkyl polyglucosides, i.e. alkyl polyglycosides in which the polyglycosyl component is a glucose unit and the alkyl component is an n-alkyl group, are preferably used.
The detergent tablets according to the invention may advantageously contain alkyl polyglycosides, APG contents of more than 0.2% by weight, based on the tablet as a whole, being preferred.
Particularly preferred detergent tablets contain APGs in quantities of 0.2 to 10% by weight, preferably in quantities of 0.2 to 5% by weight and more preferably in quantities of 0.5 to 3% by weight.
Nonionic surfactants of the amine oxide type, for example N
cocoalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxyethyl amine oxide, and the fatty acid alkanolamide type are also suitable. The quantity in which these nonionic surfactants are used is preferably no more than the quantity in which the ethoxylated fatty alcohols are used and, more preferably, no more than half that quantity.
Other suitable surfactants are polyhydroxyfatty acid amides corresponding to formula (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 atoms 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 or branched alkyl or alkenyl group containing 7 to 12 carbon atoms, R' is a linear, branched or cyclic alkyl group or an aryl group containing 2 to 8 carbon atoms and R2 is a linear, branched or cyclic alkyl group or an aryl group or an oxyalkyl group containing 1 to 8 carbon atoms, C~_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 alkoxylated, preferably ethoxylated or propoxylated, derivatives of that group.
[Z] is preferably obtained by reductive amination of a reduced sugar, for example glucose, fructose, maltose, lactose, galactose, mannose or xylose. The N-alkoxy- or N-aryloxy-substituted compounds may then be converted into the required polyhydroxyfatty acid amides by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst, for example in accordance with the teaching of International patent application WO-A-95/07331.
In detergent tablets preferably obtainable in accordance with the invention, the content of nonionic surfactants in the surfactant granules is from 1 to 15% by weight, preferably from 2.5 to 10% by weight and more preferably from 5 to 7.5% by weight, based on the weight of the surfactant granules.
5 Irrespective of whether anionic or nonionic surfactants or mixtures of these surfactant classes are optionally amphteric or cationic surfactants are used in the surfactant granules, preferred processes according to the invention for the production of detergent tablets are characterized in that the surfactant content of the surfactant-containing granules is from 5 to 10 60% by weight, preferably from 10 to 50% by weight and more preferably from 15 to 40% by weight, based on the surfactant granules.
The surfactant granules may be used in varying quantities in the detergent tablets or in individual phases of multiphase tablets. Preferred detergent tablets produced in accordance with the invention are 15 characterized in that the surfactant-containing granules make up - based on tablet weight - from 40 to 95% by weight, preferably from 45 to 85% by weight and more preferably from 55 to 75% by weight of the detergent tablets or an individual phase of the detergent tablet. Corresponding processes according to the invention are characterized in that the 20 surfactant granules are mixed with other treatment components to form a tablettable premix which contains from 40 to 95% by weight, preferably from 45 to 85% by weight and more preferably from 55 to 75% by weight of the surfactant granules.
It can be of advantage from the pertormance point of view if certain classes of surfactants are missing from certain phases of the detergent tablets or from the entire tablet, i.e. from every phase. In another important embodiment of the present invention, therefore, at least one phase of the tablets is free from nonionic surfactants.
Conversely, a positive effect can also be obtained through the presence of certain surfactants in individual phases or in the tablet as a whole, i.e. in every phase. Introducing the alkyl polyglycosides described above has proved to be of particular advantage, so that detergent tablets in which at least one phase of the tablet contains alkyl polyglycosides are preferred.
As with the nonionic surfactants, the omission of anionic surfactants from individual phases or from all phases can result in detergent tablets which are more suitable for certain applications. Accordingly, detergent tablets where at least one phase of the tablet is free from anionic surfactants are also possible in accordance with the present invention.
Besides the detersive ingredients, builders are the most important ingredients of detergents. Any of the builders normally used in detergents may be present in the detergent granules, but also as part of the premix, including in particular zeolites, silicates, carbonates, organic co-builders and also - providing there are no ecological objections to their use -phosphates. The latter are particularly preferred builders in dishwasher tablets.
Suitable silicates are any salts of orthosilicic acid Si(OH)4 and self condensation products thereof. In the interests of clarity, the silicates -"formula-wise" - are often not formulated like the other salts, but are formally divided into oxides. Although the silicates can have very different structures, they are based on the following simple building principle: each Si atom is always surrounded by four O atoms and only the different linkage of these Si04 units provides the individual silicate classes. The first main type is formed by silicates with independent "discrete" anions such as, for example, orthosilicates with the anion [Si04]2- (so-called neosilicates or "island silicates") or di- and tri-silicates (so-called sorosilicates or group silicates) or cyclosilicates (ring silicates) where the [Si04] tetrahedrons are arranged in rings. The second main type are so-called inosilicates (chain and band silicates) where the [Si04] tetrahedrons are put together to form chains, i.e. one-dimensionally unlimited structures which, practically, are polymers of the anion [Si03]2-. These include the large number of metasilicates. By combining two chains, double chains or bands containing the anion [S14O»]s- are formed. Phyllosilicates (sheet and layer silicates) form the third main type. In these silicates, the [Si04] tetrahedrons are linked together in one plane. Accordingly, they form layer lattices and are polymers of the anion [Sl4O~p]4-. The fourth main type are the tectosilicates (framework silicates) in which the linkage of the [Si04] tetrahedrons continues in all three spatial directions. Accordingly, tectosilicates are, practically, polymers of Si02.
Crystalline layer-form sodium silicates particularly suitable as builders in accordance with the invention correspond to the general formula NaMSiX02x+~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 ~- and b-sodium disilicates Na2Si205yH20 are particularly preferred, [i-sodium disilicate being obtainable, for example, by the process described in International patent application WO-A- 91108171.
Other useful builders are amorphous sodium silicates with a modulus (Na20:Si02 ratio) of 1:2 to 1:3.3, preferably 1:2 to 1:2.8 and more preferably 1:2 to 1:2.6 which dissolve with delay and exhibit multiple wash cycle properties. The delay in dissolution in relation to conventional amorphous sodium silicates can have been obtained in various ways, for example by surface treatment, compounding, compacting or by overdrying.
In the context of the invention, the term "amorphous" is also understood to encompass "X-ray amorphous". In other words, the silicates do not produce any of the sharp X-ray reflexes typical of crystalline substances in X-ray diffraction experiments, but at best one or more maxima of the scattered X-radiation which have a width of several degrees of the diffraction angle. However, particularly good builder properties may even be achieved where the silicate particles produce crooked or even sharp diffraction maxima in electron diffraction experiments. This may be interpreted to mean that the products have microcrystalline regions between 10 and a few hundred nm in size, values of up to at most 50 nm and, more particularly, up to at most 20 nm being preferred. So-called X
ray amorphous silicates such as these, which also dissolve with delay in relation to conventional waterglasses, are described for example in German patent application DE-A-44 00 024. Compacted amorphous silicates, compounded amorphous silicates and overdried X-ray-amorphous silicates are particularly 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 preferred to use, for example, a 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 VEGOBOND
AX~ and which may be described by the following formula:
nNa20 ~ (1-n)K20 ~ AI203 ~ (2 - 2.5)Si02 ~ (3.5 - 5.5) H20.
The zeolite may be used both as a builder in a granular compound and as a kind of "powder" to be applied to the entire mixture to be tabletted, both routes normally being used to incorporate the zeolite in the premix.

Suitable zeolites have a mean particle size of less than 10 pm (volume distribution, as measured by the Coulter Counter Method) and contain preferably 18 to 22% by weight and more preferably 20 to 22% by weight of bound water.
The generally known phosphates may of course also be used as builders providing their use should not be avoided on ecological grounds.
Among the large number of commercially available phosphates, alkali metal phosphates have the greatest importance in the detergent industry, pentasodium triphosphate and pentapotassium triphosphate (sodium and potassium tripolyphosphate) being particularly preferred.
"Alkali metal phosphates" is the collective term for the alkali metal (more particularly sodium and potassium) salts of the various phosphoric acids, including metaphosphoric acids (HP03)n and orthophosphoric acid (H3P04) and representatives of higher molecular weight. The phosphates combine several advantages: they act as alkalinity sources, prevent lime deposits on machine parts and lime incrustations in fabrics and, in addition, contribute towards the cleaning effect.
Sodium dihydrogen phosphate (NaH2P04) exists as the dehydrate (density 1.91 gcm'3, melting point 60°) and as the monohydrate (density 2.04 gcm-3). Both salts are white readily water-soluble powders which, on heating, lose the water of crystallization and, at 200°C, are converted into the weakly acidic diphosphate (disodium hydrogen diphosphate, Na2H2P207) and, at higher temperatures, into sodium trimetaphosphate (Na3P30s) and Maddrell's salt (see below). NaH2P04 shows an acidic reaction. It is formed by adjusting phosphoric acid with sodium hydroxide to a pH value of 4.5 and spraying the resulting "mash". Potassium dihydrogen phosphate (primary or monobasic potassium phosphate, potassium biphosphate, KDP), KH2P04, is a white salt with a density of 2.33 gcm-3, has a melting point of 253° [decomposition with formation of potassium polyphosphate (KP03)x) and is readily soluble in water.
Disodium hydrogen phosphate (secondary sodium phosphate), NaZHP04, is a colorless, readily water-soluble crystalline salt. It exists in water-free form and with 2 moles (density 2.066 gcm-3, water loss at 95°), 7 5 moles (density 1.68 gcm-3, melting point 48° with loss of 5 H20) and moles of water (density 1.52 gcm-3, melting point 35° with loss of 5 H20), becomes water-free at 100° and, on fairly intensive heating, is converted into the diphosphate Na4P207. Disodium hydrogen phosphate is prepared by neutralization of phosphoric acid with soda solution using phenol-10 phthalein as indicator. Dipotassium hydrogen phosphate (secondary or dibasic potassium phosphate), K2HP04, is an amorphous white salt which is readily soluble in water.
Trisodium phosphate, tertiary sodium phosphate, Na3P04, consists of colorless crystals which have a density of 1.62 gcm-3 and a melting point 15 of 73-76° (decomposition) as the dodecahydrate, a melting point of 100° as the decahydrate (corresponding to 19-20% P205) and a density of 2.536 gcm-3 in water-free form (corresponding to 39-40% P205). Trisodium phosphate is readily soluble in water through an alkaline reaction and is prepared by concentrating a solution of exactly 1 mole of disodium 20 phosphate and 1 mole of NaOH by evaporation. Tripotassium phosphate (tertiary or tribasic potassium phosphate), K3P04, is a white deliquescent granular powder with a density of 2.56 gcm-3, has a melting of 1340°
and is readily soluble in water through an alkaline reaction. It is formed, for example, when Thomas slag is heated with coal and potassium sulfate.

25 Despite their higher price, the more readily soluble and therefore highly effective potassium phosphates are often preferred to corresponding sodium compounds in the detergent industry.
Tetrasodium diphosphate (sodium pyrophosphate), Na4P207, exists in water-free form (density 2.534 gcm-3, melting point 988°, a figure of 880°

has also been mentioned) and as the decahydrate (density 1.815 - 1.836 gcm-3, melting point 94° with loss of water). Both substances are colorless crystals which dissolve in water through an alkaline reaction. Na4P207 is formed when disodium phosphate is heated to >200° or by reacting phosphoric acid with soda in a stoichiometric ratio and spray-drying the solution. The decahydrate complexes heavy metal salts and hardness salts and, hence, reduces the hardness of water. Potassium diphosphate (potassium pyrophosphate), K4P20~, exists in the form of the trihydrate and is a colorless hygroscopic powder with a density of 2.33 gcm-3 which is soluble in water, the pH value of a 1 % solution at 25° being 10.4.
Relatively high molecular weight sodium and potassium phosphates are formed by condensation of NaH2P04 or KH2P04. They may be divided into cyclic types, namely the sodium and potassium metaphosphates, and chain types, the sodium and potassium polyphosphates. The chain types in particular are known by various different names: fused or calcined phosphates, Graham's salt, Kurrol's salt and Maddrell's salt. All higher sodium and potassium phosphates are known collectively as condensed phosphates.
The industrially important pentasodium triphosphate, Na5P30~o (sodium tripolyphosphate), is a non-hygroscopic white water-soluble salt which crystallizes without water or with 6 H20 and which has the general formula Na0-[P(O)(ONa)-OJn-Na where n = 3. Around 17 g of the salt free from water of crystallization dissolve in 100 g of water at room temperature, around 20 g at 60° and around 32 g at 100°. After heating of the solution for 2 hours to 100°, around 8% orthophosphate and 15% diphosphate are formed by hydrolysis. In the preparation of pentasodium triphosphate, phosphoric acid is reacted with soda solution or sodium hydroxide in a stoichiometric ratio and the solution is spray-dried. Similarly to Graham's salt and sodium diphosphate, pentasodium triphosphate dissolves many insoluble metal compounds (including lime soaps, etc.). Pentapotassium triphosphate, K5P30~o (potassium tripolyphosphate), is marketed for example in the form of a 50% by weight solution (> 23% P205, 25% K20).
The potassium polyphosphates are widely used in the detergent industry.
Sodium potassium tripolyphosphates, which may also be used in accordance with the invention, also exist. They are formed for example when sodium trimetaphosphate is hydrolyzed with KOH:
(NaP03)3 + 2 KOH -> Na3K2P30~o + H20 According to the invention, they may be used in exactly the same way as sodium tripolyphosphate, potassium tripolyphosphate or mixtures thereof. Mixtures of sodium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of potassium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of sodium tripolyphosphate and potassium tripolyphosphate and sodium potassium tripolyphosphate may also be used in accordance with the invention.
In addition to the builders described above, the surfactant granules may also contain polymers, so-called co-builders. These co-builders may also be part of the premix without being present in the surfactant granules.
An important class of polymers with co-builder properties are the polymeric polycarboxylates. Such (co)polymeric polycarboxylates are, for example, the alkali metal salts of polyacrylic or polymethacrylic acid, for example those with a relative molecular weight of 500 to 70,000 g/mole.
The molecular weights mentioned in this specification for polymeric polycarboxylates are weight-average molecular weights MW of the particular acid form which, basically, were determined by gel permeation chromatography (GPC) using a UV detector. The measurement was carried out against an external polyacrylic acid standard which provides realistic molecular weight values by virtue of its structural similarity to the polymers investigated. These values differ distinctly from the molecular weights measured against polystyrene sulfonic acids as standard. The molecular weights measured against polystyrene sulfonic acids are generally higher than the molecular weights mentioned in this specification.
Particularly suitable polymers are polyacrylates which preferably have a molecular weight of 2,000 to 20,000 g/mole. By virtue of their superior solubility, preferred representatives of this group are the short chain polyacrylates which have molecular weights of 2,000 to 10,000 g/mole and, more particularly, 3,000 to 5,000 g/mole.
Also suitable are copolymeric polycarboxylates, particularly those of acrylic acid with methacrylic acid and those of acrylic acid or methacrylic acid with malefic acid. Acrylic acid/maleic acid copolymers containing 50 to 90% by weight of acrylic acid and 50 to 10% by weight of malefic acid have proved to be particularly suitable. Their relative molecular weights, based on the free acids, are generally in the range from 2,000 to 70,000 g/mole, preferably in the range from 20,000 to 50,000 g/mole and more preferably in the range from 30,000 to 40,000 g/mole.
In order to improve solubility in water, the polymers may also contain allyl sulfonic acids, such as allyloxybenzene sulfonic acid and methallyl sulfonic acid, as monomer. Other particularly preferred polymers are biodegradable polymers of more than two different monomer units, for example those which contain salts of acrylic acid and malefic acid and vinyl alcohol or vinyl alcohol derivatives as monomers or those which contain salts of acrylic acid and 2-alkylallyl sulfonic acid and sugar derivatives as monomers.
Other preferred copolymers are those which are described in German patent applications DE-A-43 03 320 and DE-A-44 17 734 and which preferably contain acrolein and acrylic acid/acrylic acid salts or acrolein and vinyl acetate as monomers. Other preferred builders are polymeric aminodicarboxylic acids, salts or precursors thereof. Particular preference is attributed to polyaspartic acids or salts and derivatives thereof which, according to German patent application DE-A-195 40 086, are also said to have a bleach-stabilizing effect in addition to their co-builder properties.
Other suitable builders are polyacetals which may be obtained by reaction of dialdehydes with polyol carboxylic acids containing 5 to 7 carbon atoms and at least 3 hydroxyl groups. Preferred polyacetals are obtained from dialdehydes, such as glyoxal, glutaraldehyde, terephthal-aldehyde and mixtures thereof and from polyol carboxylic acids, such as gluconic acid and/or glucoheptonic acid.
Other organic cobuilders suitable for use in the detergent tablets according to the invention are, in particular, polycarboxylates/polycarboxylic acids, dextrins, other organic cobuilders (see below) and phosphonates.
These classes of substances are described in the following.
Useful organic builders are, for example, the polycarboxylic acids usable, for example, in the form of their sodium salts, polycarboxylic acids in this context being understood to be carboxylic acids which bear more than one acid function. Examples of such carboxylic acids are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, malefic acid, fumaric acid, sugar acids, aminocarboxylic acids, nitrilotriacetic acid (NTA), providing its use is not ecologically unsafe, and mixtures thereof. Preferred salts are the salts of the polycarboxylic acids, such as citric acid, adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids and mixtures thereof.
The acids per se may also be used. Besides their builder effect, the acids also typically have the property of an acidifying component and, hence, also serve to establish a relatively low and mild pH value in detergents. Citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid and mixtures thereof are particularly mentioned in this regard.
Other suitable organic builders are dextrins, for example oligomers or polymers of carbohydrates which may be obtained by partial hydrolysis 5 of starches. The hydrolysis may be carried out by standard methods, for example acid- or enzyme-catalyzed methods. The end products are preferably hydrolysis products with average molecular weights of 400 to 500,000 g/mole. A polysaccharide with a dextrose equivalent (DE) of 0.5 to and, more particularly, 2 to 30 is preferred, the DE being an accepted 10 measure of the reducing effect of a polysaccharide by comparison with dextrose which has a DE of 100. Both maltodextrins with a DE of 3 to 20 and dry glucose sirups with a DE of 20 to 37 and also so-called yellow dextrins and white dextrins with relatively high molecular weights of 2,000 to 30,000 g/mole may be used.
15 The oxidized derivatives of such dextrins are their reaction products with oxidizing agents which are capable of oxidizing at least one alcohol function of the saccharide ring to the carboxylic acid function. Dextrins thus oxidized and processes for their production are known, for example, from European patent applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0 20 472 042 and EP-A-0 542 496 and from International patent applications WO 92118542, WO 93108251, WO 93116110, WO 94128030, WO 95107303, WO 95/12619 and WO 95120608. An oxidized oligosaccharide corresponding to German patent application DE-A-196 00 018 is also suitable. A product oxidized at C6 of the saccharide ring can be particularly 25 advantageous.
Other suitable co-builders are oxydisuccinates and other derivatives of disuccinates, preferably ethylenediamine disuccinate. Ethylenediamine-N,N'-disuccinate (EDDS) is preferably used in the form of its sodium or magnesium salts. Glycerol disuccinates and glycerol trisuccinates are also preferred in this connection. The quantities used in zeolite-containing and/or silicate-containing formulations are from 3 to 15% by weight.
Other useful organic co-builders are, for example, acetylated hydroxycarboxylic acids and salts thereof which may optionally be present in lactone form and which contain at least 4 carbon atoms, at least one hydroxy group and at most two acid groups. Co-builders such as these are described, for example, in International patent application WO 95120029.
Another class of substances with co-builder properties are the phosphonates, more particularly hydroxyalkane and aminoalkane phos phonates. Among the hydroxyalkane phosphonates, 1-hydroxyethane-1,1 diphosphonate (HEDP) is particularly important as a co-builder. It is preferably used in the form of the sodium salt, the disodium salt showing a neutral reaction and the tetrasodium salt an alkaline reaction (pH 9).
Preferred aminoalkane phosphonates are ethylenediamine tetramethylene phosphonate (EDTMP), diethylenetriamine pentamethylenephosphonate (DTPMP) and higher homologs thereof. They are preferably used in the form of the neutrally reacting sodium salts, for example as the hexasodium salt of EDTMP or as the hepta- and octasodium salts of DTPMP. Of the phosphonates, HEDP is preferably used as a builder. In addition, the aminoalkane phosphonates have a pronounced heavy metal binding capacity. Accordingly, it can be of advantage, particularly where the detergents also contain bleach, to use aminoalkane phosphonates, more particularly DTPMP, or mixtures of the phosphonates mentioned.
In addition, any compounds capable of forming complexes with alkaline earth metal ions may be used as co-builders.
The quantity of builder used is normally between 10 and 70% by weight, preferably between 15 and 60% by weight and more preferably between 20 and 50% by weight. The quantity of builder used is again dependent upon the particular application envisaged. It has been found that excessive quantities of carbonates in the surfactant granules can be problematical in certain formulations so that it is of advantage in such formulations to introduce the carbonates into the detergent tablets as part of the premix - providing its use is desired - and not through the surfactant granules. With formulations such as these, the production of detergent tablets where the sodium and/or potassium carbonate content of the surfactant granules is below 15% by weight, preferably below 10% by weight and more preferably below 5% by weight, based on the weight of the surfactant granules, is preferred.
Besides the constituents mentioned (surfactant and builder), the detergent tablets produced in accordance with the invention and hence the premixes to be tabletted additionally contain one or more substances from the group of disintegration aids, bleaching agents, bleach activators, enzymes, pH regulators, perfumes, perfume carriers, fluorescers, dyes, foam inhibitors, silicone oil, redepositiori inhibitors, optical brighteners, discoloration inhibitors, dye transfer inhibitors and corrosion inhibitors. In the following paragraphs, the individual substances are described partly as a constituent of the premix and partly as a constituent of the detergent tablets produced from the premix.
Among the compounds yielding H202 in water used as bleaching agents, sodium percarbonate is particularly important. "Sodium percarbonate" is a non-specific term used for sodium carbonate peroxo-hydrates which, strictly speaking, are not "percarbonates" (i.e. salts of per-carbonic acid), but hydrogen peroxide adducts with sodium carbonate. The commercial material has the mean composition 2 Na2C03 ~ 3 H202 and, accordingly, is not a peroxycarbonate. Sodium percarbonate forms a white water-soluble powder with a density of 2.14 gcm-3 which readily decom-poses into sodium carbonate and bleaching or oxidizing oxygen.

Sodium carbonate peroxohydrate was obtained for the first time in 1899 by precipitation with ethanol from a solution of sodium carbonate in hydrogen peroxide, but was mistakenly regarded as peroxycarbonate. It was only in 1909 that the compound was recognised as a hydrogen peroxide addition compound. Nevertheless, the historical name "sodium percarbonate" has been adopted in practice.
On an industrial scale, sodium percarbonate is mainly produced by precipitation from aqueous solution (so-called wet process). In this pro-cess, aqueous solutions of sodium carbonate and hydrogen peroxide are combined and the sodium percarbonate is precipitated by salting-out agents (mainly sodium chloride), crystallization aids (for example polyphos-phates, polyacrylates) and stabilizers (for example Mg2+ ions). The precipitated salt which still contains 5 to 12% by weight of mother liquor is then removed by centrifuging and dried at 90°C in fluidized bed dryers.
The bulk density of the end product can vary between 800 and 1200 g/I
according to the production process. In general, the percarbonate is stabilized by an additional coating. Coating processes and materials are widely described in the patent literature. Basically, any commercially available percarbonate types as marketed, for example, by Solvay Interox, Degussa, Kemira and Akzo may be used in accordance with the present invention.
Other useful bleaching agents are, for example, sodium perborate tetrahydrate and sodium perborate monohydrate, peroxypyrophosphates, citrate perhydrates and H202-yielding peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or diperdodecane dioic acid. Where bleaching agents are used, it is again possible to leave out surfactants and/or builders so that pure bleach tablets can be produced. If such bleach tablets are to be added to laundry, a combination of sodium percarbonate with sodium sesquicarbonate is preferably used irrespective of what other ingredients the tablets contain. If detergent or bleach tablets for dishwashing machines are being produced, bleaching agents from the group of organic bleaches may also be used.
Typical organic bleaching agents are diacyl peroxides, such as dibenzoyl peroxide for example. Other typical organic bleaching agents are the peroxy acids, of which alkyl peroxy acids and aryl peroxy acids are particularly mentioned as examples. Preferred representatives are (a) peroxybenzoic acid and ring-substituted derivatives thereof, such as alkyl peroxybenzoic acids, but also peroxy-a-naphthoic acid and magnesium monoperphthalate, (b) aliphatic or substituted aliphatic peroxy acids, such as peroxylauric acid, peroxystearic acid, s-phthalimidoperoxycaproic acid [phthaloiminoperoxyhexanoic acid (PAP)], o-carboxybenzamido-peroxycaproic acid, N-nonenylamidoperadipic acid and N-nonenylamidopersuccinates, and (c) aliphatic and araliphatic peroxydicarboxylic acids, such as 1,12-diperoxycarboxylic acid, 1,9-diperoxyazelaic acid, diperoxysebacic acid, diperoxybrassylic acid, diperoxyphthalic acids, 2-decyldiperoxybutane-1,4-dioic acid, N,N-terephthaloyl-di(6-aminopercaproic acid).
Other suitable bleaching agents in dishwasher tablets are chlorine and bromine-releasing substances. Suitable chlorine- or bromine-releasing materials are, for example, heterocyclic N-bromamides and N-chloramides, for example trichloroisocyanuric acid, tribromoisocyanuric acid, dibromo isocyanuric acid and/or dichloroisocyanuric acid (DICA) and/or salts thereof with cations, such as potassium and sodium. Hydantoin compounds, such as 1,3-dichloro-5,5-dimethyl hydantoin, are also suitable.
In order to obtain an improved bleaching effect at washing temperatures of 60°C or lower, bleach activators may be incorporated in the premix used to produce the detergent tablets according to the invention. Bleach activators which support the effect of the bleaching agents are, for example, compounds which contain one or more N- or O-acyl groups, such as substances from the class of anhydrides, esters, imides and acylated imidazoles or oximes. Examples are tetraacetyl ethylenediamine (TAED), tetraacetyl methylenediamine (TAMD) and 5 tetraacetyl hexylenediamine (TAHD) and also pentaacetyl glucose (PAG), 1,5-diacetyl-2,2-dioxohexaydro-1,3,5-triazine (DADHT) and isatoic anhydride (ISA).
Suitable bleach activators are compounds which form aliphatic peroxocarboxylic acids containing preferably 1 to 10 carbon atoms and 10 more preferably 2 to 4 carbon atoms and/or optionally substituted perbenzoic acid under perhydrolysis conditions. Substances bearing O-and/or N-acyl groups with the number of carbon atoms mentioned and/or optionally substituted benzoyl groups are suitable. Preferred bleach activators are polyacylated alkylenediamines, more particularly tetraacetyl 15 ethylenediamine (TAED), acylated triazine derivatives, more particularly 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycol-urils, more particularly tetraacetyl glycoluril (TAGU), N-acylimides, more particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates, more particularly n-nonanoyl- or isononanoyl-oxybenzenesulfonate (n- or 20 iso-NOBS), carboxylic anhydrides, more particularly phthalic anhydride, acylated polyhydric alcohols, more particularly triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydrofuran, n-methyl morpholinium acetonitrile methyl sulfate (MMA) and the enol esters known from German patent applications DE 196 16 693 and DE 196 16 767, acetylated sorbitol 25 and mannitol and mixtures thereof (SORMAN), acylated sugar derivatives, more particularly pentaacetyl glucose (PAG), pentaacetyl fructose, tetraacetyl xylose and octaacetyl lactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example N-benzoyl caprolactam. Substituted hydrophilic acyl acetals and acyl lactams are also preferably used. Combinations of conventional bleach activators may also be used.
In addition to or instead of the conventional bleach activators mentioned above, so-called bleach catalysts may also be incorporated.
These substances are bleach-boosting transition metal salts or transition metal complexes such as, for example, manganese-, iron-, cobalt-, ruthenium- or molybdenum-salen or -carbonyl complexes. Manganese, iron, cobalt, ruthenium, molybdenum, titanium, vanadium and copper complexes with nitrogen-containing tripod ligands and cobalt-, iron-, copper- and ruthenium-ammine complexes may also be used as bleach catalysts.
Bleach activators from the group of polyacylated alkylenediamines, more particularly tetraacetyl ethylenediamine (TAED), N-acyl imides, more particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates, more particularly n-nonanoyl- or isononanoyl-oxybenzenesulfonate (n- or iso-NOBS), n-methyl morpholinium acetonitrile methyl sulfate (MMA) are preferably used, preferably in quantities of up to 10% by weight, more preferably in quantities of 0.1 % by weight to 8% by weight, most preferably in quantities of 2 to 8% by weight and, with particular advantage, in quantities of 2 to 6% by weight, based on the detergent as a whole.
Bleach-boosting transition metal complexes, more particularly containing the central atoms Mn, Fe, Co, Cu, Mo, V, Ti and/or Ru, preferably selected from the group of manganese and/or cobalt salts and/or complexes, more preferably the cobalt (ammine) complexes, cobalt (acetate) complexes, cobalt (carbonyl) complexes, chlorides of cobalt or manganese and manganese sulfate, are also present in typical quantities, preferably in a quantity of up to 5% by weight, more preferably in a quantity of 0.0025% by weight to 1 % by weight and most preferably in a quantity of 0.01 % by weight to 0.25% by weight, based on the detergent as a whole.

In special cases, however, more bleach activator may even be used.
In view of their oxidizing effect, the bleaching agents are advantageously separated from other ingredients, for which purpose multiphase tablets are particularly suitable. Detergent tablets in which one of the phases of the tablets contains bleaching agents while another phase contains bleach activators are preferred.
It can also be of advantage to separate the bleaching agents from other ingredients. Multiphase tablets in which one phase contains bleaching agents while another phase contains enzymes are also preferred. Suitable enzymes are; in particular, those from the classes of hydrolases, such as proteases, esterases, lipases or lipolytic enzymes, amylases, cellulases or other glycosyl hydrolases and mixtures thereof. All these hydrolases contribute to the removal of stains, such as protein-containing, fat-containing or starch-containing stains, and discoloration in the washing process. Cellulases and other glycosyl hydrolases can contribute towards color retention and towards increasing fabric softness by removing pilling and microfibrils. Oxidoreductases may also be used for bleaching and for inhibiting dye transfer. Enzymes obtained from bacterial strains or fungi, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Coprinus cinereus and Humicola insolens and from genetically modified variants are particularly suitable. Proteases of the subtilisin type are preferably used, proteases obtained from Bacillus lentus being particularly preferred. Of particular interest in this regard are enzyme mixtures, for example of protease and amylase or protease and lipase or lipolytic enzymes or protease and cellulase or of cellulase and lipase or lipolytic enzymes or of protease, amylase and lipase or lipolytic enzymes or protease, lipase or lipolytic enzymes and cellulase, but especially protease-and/or lipase-containing mixtures or mixtures with lipolytic enzymes.
Examples of such lipolytic enzymes are the known cutinases. Peroxidases or oxidases have also been successfully used in some cases. Suitable amylases include in particular a-amylases, isoamylases, pullanases and pectinases. Preferred cellulases are cellobiohydrolases, endoglucanases and ~i-glucosidases, which are also known as cellobiases, and mixtures thereof. Since the various cellulase types differ in their CMCase and avicelase activities, the desired activities can be established by mixing the cellulases in the appropriate ratios.
Other enzymes are of course used in dishwasher tablets to allow for the different substrates treated and the different soils. Particularly suitable enzymes for dishwasher tablets are those from the classes of hydrolases, such as proteases, esterases, lipases or lipolytic enzymes, amylases, glycosyl hydrolases and mixtures thereof. All these hydrolases contribute to the removal of stains, such as protein-containing, fat-containing or starch-containing stains. Oxidoreductases may also be used for bleaching and for inhibiting dye transfer. Enzymes obtained from bacterial strains or fungi, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Coprinus cinereus and Humicola insolens and from genetically modified variants are particularly suitable. Proteases of the subtilisin type are preferably used, proteases obtained from Bacillus lentus being particularly preferred. Of particular interest in this regard are enzyme mixtures, for example of protease and amylase or protease and lipase or lipolytic enzymes or of protease, amylase and lipase or lipolytic enzymes or protease, lipase or lipolytic enzymes, 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 been successfully used in some cases. Suitable amylases include in particular a-amylases, isoamylases, pullanases and pectinases.
The enzymes may be adsorbed to supports and/or encapsulated in membrane materials to protect them against premature decomposition.

The percentage content of the enzymes, enzyme mixtures or enzyme granules may be, for example, from about 0.1 to 5% by weight and is preferably from 0.5 to about 4.5% by weight, based on the premix(es).
To protect the tableware or the machine itself, the detergent tablets according to the invention may contain corrosion inhibitors, silver protectors being particularly important for dishwashing machines. Known corrosion inhibitors may be used. Above all, silver protectors selected from the group of triazoles, benzotriazoles, bisbenzotriazoles, aminotriazoles, alkyl aminotriazoles and the transition metal salts or complexes may generally be used. Benzotriazole and/or alkylaminotriazole is/are particularly preferred. In addition, dishwashing formulations often contain corrosion inhibitors containing active chlorine which are capable of distinctly reducing the corrosion of silver surfaces. Chlorine-free dishwashing detergents contain in particular oxygen- and nitrogen-containing organic redox-active compounds, such as dihydric and trihydric phenols, for example hydroquinone, pyrocatechol, hydroxyhydroquinone, gallic acid, phloro-glucinol, pyrogallol and derivatives of these compounds. Salt-like and complex-like inorganic compounds, such as salts of the metals Mn, Ti, Zr, Hf, V, Co and Ce are also frequently used. Of these, the transition metal salts selected from the group of manganese and/or cobalt salts and/or complexes are preferred, cobalt(ammine) complexes, cobalt(acetate) complexes, cobalt(carbonyl) complexes, chlorides of cobalt or manganese and manganese sulfate being particularly preferred. Zinc compounds may also be used to prevent corrosion of tableware.
If corrosion inhibitors are used in multiphase tablets, they are preferably separated from the bleaching agents. Accordingly, detergent tablets where one phase contains bleaching agents while another phase contains corrosion inhibitors are preferred.
Other ingredients which may be part of the detergent tablets in accordance with the invention are, for example, dyes, optical brighteners, perfumes, soil release compounds, soil repellents, antioxidants, fluorescers, foam inhibitors, silicone and/or paraffin oils, dye transfer inhibitors, redeposition inhibitors, detergency boosters, etc.
5 In order to improve their aesthetic impression, the detergent tablets according to the invention may be completely partly colored with suitable dyes. Preferred dyes, which are not difficult for the expert to choose, have high stability in storage, are not affected by the other ingredients of the detergents or by light and do not have any pronounced substantivity for the 10 treated substrates, for example textile fibers or tableware, so as not to color them.
Any dyes which can be destroyed by oxidation in the washing process and mixtures thereof with suitable blue dyes, so-called blueing agents, are preferably used in the detergent tablets produced in 15 accordance with the invention. It has proved to be of advantage to use dyes which are soluble in water or - at room temperature - in liquid organic substances. Suitable dyes are, for example, anionic dyes, for example anionic nitroso dyes. One possible dye is, for example, naphthol green (Color Index (CI) Part 1: Acid Green 1; Part 2: 10020), which is 20 commercially available for example as Basacid~ Grun 970 from BASF, Ludwigshafen, and mixtures thereof with suitable blue dyes. Other suitable dyes are Pigmosol~ Blau 6900 (CI 74160), Pigmosol~ Griin 8730 (CI
74260), Basonyl~ Rot 545 FL (CI 45170), Sandolan~ Rhodamin EB 400 (CI 45100), Basacid~ Gelb 094 (CI 47005), Sicovit~ Patentblau 85 E 131 25 (CI 42051 ), Acid Blue 183 (CAS 12217-22-0, CI Acid Blue 183), Pigment Blue 15 (CI 74160), Supranol~ Blau GLW (CAS 12219-32-8, CI Acid Blue 221)), Nylosan~ Gelb N-7GL SGR (CAS 61814-57-1, CI Acid Yellow 218) and/or Sandolan~ Blau (CI Acid Blue 182, CAS 12219-26-0).
In selecting the dye, it is important to ensure that the dye does not have an excessive affinity for the textile surfaces and, in particular, for synthetic fibers. Another factor to be taken into account in the selection of suitable dyes is that dyes differ in their stability to oxidation. Generally speaking, water-insoluble dyes are more stable to oxidation than water-soluble dyes. The concentration of the dye in the detergents varies according to its solubility and hence its sensitivity to oxidation. In the case of readily water-soluble dyes, for example the above-mentioned Basacid~
Grun and Sandolan~ Blau, dye concentrations in the range from a few 10~
to 10-3 % by weight are typically selected. By contrast, in the case of the pigment dyes which are particularly preferred for their brilliance, but which are less readily soluble in water, for example the above-mentioned Pigmosol~ dyes, suitable concentrations of the dye in detergents are typically of the order of a few 10-3 to 10-4 % by weight.
The premixes to be tabletted in accordance with the invention may contain one or more optical brightener(s). These substances, which are also known as "whiteners", are used in modern detergents because even freshly washed and bleached white laundry has a slight yellowish tinge.
Optical brighteners are organic dyes which convert part of the invisible UV
radiation in sunlight into longer wave blue light. The emission of this blue light fills the "gap" in the light reflected by the fabric, so that a fabric treated with optical brightener appears whiter and brighter to the eye. Since the action mechanism of brighteners presupposes their absorption onto the fibers, brighteners are differentiated according to the fibers "to be colored", for example as brighteners for cotton, polyamide or polyester fibers. The commercially available brighteners suitable for incorporation in detergents largely belong to five structural groups, namely: the stilbene, the diphenyl stilbene, the coumarin/quinoline and the diphenyl pyrazoline group and the group where benzoxazole or benzimidazole is combined with conjugated systems. Conventional brighteners are reviewed, for example, in G.

Jakobi, A. Lohr "Detergents and Textile Washing", VCH-Verlag, Weinheim, 1987, pages 94 to 100. Suitable brighteners are, for example, salts of 4,4'-bis-[(4-anilino-6-morpholino-s-triazin-2-yl)-amino]-stilbene-2,2'-disulfonic acid or compounds of similar structure which, instead of the morpholino group, contain a diethanolamino group, a methylamino group, an anilino group or a 2-methoxyethylamino group. Brighteners of the substituted diphenyl styryl type, for example alkali metal salts of 4,4'-bis-(2-sulfostyryl)-diphenyl, 4,4'-bis-(4-chloro-3-sulfostyryl)-diphenyl or 4-(4-chlorostyryl)-4'-(2-sulfostyryl)-diphenyl, may also be present. Mixtures of the brighteners mentioned above may also be used.
Perfumes are added to the detergent tablets according to the invention in order to improve the aesthetic impression created by the products and to provide the consumer not only with the required performance but also with a visually and sensorially "typical and unmistakable" product. Suitable perfume oils or perfumes include individual perfume compounds, for example synthetic products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type. Perfume com-pounds of the ester type are, for example, benzyl acetate, phenoxyethyl isobutyrate, p-tert.butyl cyclohexyl acetate, linalyl acetate, dimethyl benzyl carbinyl acetate, phenyl ethyl acetate, linalyl benzoate, benzyl formate, ethyl methyl phenyl glycinate, allyl cyclohexyl propionate, styrallyl propionate and benzyl salicylate. The ethers include, for example, benzyl ethyl ether; the aldehydes include, for example, the linear alkanals containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetal-dehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal; the ketones include, for example, the ionones, a-isomethyl ionone and methyl cedryl ketone; the alcohols include anethol, citronellol, eugenol, geraniol, linalool, phenyl ethyl alcohol and terpineol and the hydrocarbons include, above all, the terpenes, such as limonene and pinene. However, mixtures of various perfumes which together produce an attractive perfume note are preferably used. Perfume oils such as these may also contain natural perfume mixtures obtainable from vegetable sources, for example pine, citrus, jasmine, patchouli, rose or ylang-ylang oil. Also suitable are clary oil, camomile oil, clove oil, melissa oil, mint oil, cinnamon leaf oil, lime blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil and labdanum oil and orange blossom oil, neroli oil, orange peel oil and sandalwood oil.
The perfume content of the detergent tablets produced in accordance with the invention is normally up to 2% 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 supports 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 addition, the detergent tablets according to the invention may also contain components with a positive effect on the removal of oil and fats from textiles by washing (so-called soil repellents). This effect becomes particularly clear when a textile which has already been repeatedly washed with a detergent according to the invention containing this oil- and fat-dissolving component is soiled. Preferred oil- and fat-dissolving compo-nents include, for example, nonionic cellulose ethers, such as methyl cellulose and methyl hydroxypropyl cellulose containing 15 to 30% by weight of methoxyl groups and 1 to 15% by weight of hydroxypropoxyl groups, based on the nonionic cellulose ether, and the polymers of phthalic acid 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.
Foam inhibitors suitable for use in the detergents according to the invention are, for example, soaps, paraffins and silicone oils which may optionally be applied to carrier materials.
The function of redeposition inhibitors is to keep the soil detached from the fibers suspended in the wash liquor and thus to prevent the soil from being re-absorbed by the washing. Suitable redeposition inhibitors are water-soluble, generally organic colloids, for example the water-soluble salts of polymeric carboxylic acids, glue, gelatine, salts of ether sulfonic acids of starch or cellulose or salts of acidic sulfuric acid esters of cellulose or starch. Water-soluble polyamides containing acidic groups are also suitable for this purpose. Soluble starch preparations and other starch products than those mentioned above, for example degraded starch, aldehyde starches, etc., may also be used. Polyvinyl pyrrolidone is also suitable. However, cellulose ethers, such as carboxymethyl cellulose (sodium salt), methyl cellulose, hydroxyalkyl cellulose, and mixed ethers, such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, methyl carboxymethyl cellulose and mixtures thereof are preferably used, for example in quantities of 0.1 to 5% by weight, based on the detergent.
Since sheet-form textiles, more particularly of rayon, rayon staple, cotton and blends thereof, can tend to crease because the individual fibers are sensitive to sagging, kinking, pressing and squeezing transversely of the fiber direction, the compositions according to the invention may contain synthetic anticrease agents, including for example synthetic products based on fatty acids, fatty acid esters, fatty acid amides, alkylol esters, alkylol amides or fatty alcohols, which are generally reacted with ethylene oxide, or products based on lecithin or modified phosphoric acid esters.

To control microorganisms, the compositions according to the invention may contain antimicrobial agents. According to the antimicrobial spectrum and the action mechanism, antimicrobial agents may be divided into bacteriostatic agents and bactericides, fungistatic agents and 5 fungicides, etc. Important representatives of these groups are, for example, benzalkonium chlorides, alkylaryl sulfates, halophenols and phenol mercury acetate, although these compounds may also be absent altogether.
In order to prevent unwanted changes in the compositions and/or 10 the fabrics treated with them attributable to the effects of oxygen and other oxidative processes, the compositions may contain antioxidants. This class of compounds includes, for example, substituted phenols, hydroquinones, pyrocatechols and aromatic amines and also organic sulfides, polysulfides, dithiocarbamates, phosphites and phosphonates.
15 Wearing comfort can be increased by the additional use of antistatic agents which are additionally incorporated in the detergents according to the invention. Antistatic agents increase surface conductivity and thus provide for the improved dissipation of any charges which have built up.
External antistatic agents are generally substances containing at least one 20 hydrophilic molecule ligand and form a more or less hygroscopic film on the surfaces. These generally interfacially active antistatic agents may be divided into nitrogen-containing antistatics (amines, amides, quaternary ammonium compounds), phosphorus-containing antistatics (phosphoric acid esters) and sulfur-containing antistatics (alkyl sulfonates, alkyl 25 sulfates). External antistatic agents are described, for example, in patent applications FR 1,156,513, GB 873,214 and GB 839,407. The lauryl (or stearyl) dimethyl benzyl ammonium chlorides disclosed therein are suitable as antistatic agents for textiles and as detergent additives and additionally develop a conditioning effect.

In order to improve the water absorption capacity and rewettability of the treated textiles and to make them easier to iron, silicone derivatives, for example, may be used in the premixes to be processed in accordance with the invention. Silicone derivatives additionally improve the rinsing out behavior of the compositions through their foam-inhibiting properties.
Preferred silicone derivatives are, for example, polydialkyl and alkylaryl siloxanes where the alkyl groups contain 1 to 5 carbon atoms and are completely or partly fluorinated. Preferred silicones are polydimethyl siloxanes which may optionally be derivatized and, in that case, are aminofunctional or quaternized or contain Si-OH-, Si-H- and/or Si-CI bonds.
The preferred silicones have viscosities at 25°C of 100 to 100,000 centistokes and may be used in quantities of 0.2 to 5% by weight, based on the detergent as a whole.
Finally, the compositions according to the invention may also contain UV filters which are absorbed onto the treated textiles and which improve the light stability of the fibers. Compounds which have these desirable properties are, for example, the compounds acting by "radiationless"
deactivation and derivatives of benzophenone with substituents in the 2 position and/or 4 position. Substituted benzotriazoles, 3-phenyl-substituted acrylates (cinnamic acid derivatives), optionally with cyano groups in the 2-position, salicylates, organic Ni complexes and natural substances, such as umbelliferone and the body's own urocanic acid.
With all the above-mentioned ingredients, advantageous properties can be obtained by separating them from other ingredients or making them up together with certain other ingredients. In the case of multiphase tablets, the individual phases may even differ in their content of the same ingredient which can afford advantages. Detergent tablets where at least two phases contain the same active substance in different quantities are preferred. As explained above, the expression "different quantity" does not relates to the absolute quantity of the ingredient in the phase, but to the relative quantity, based on the weight of the phase, i.e. is a percentage by weight, based on the individual phase.
In order to facilitate the disintegration of heavily compacted tablets, disintegration aids, so-called tablet disintegrators, may be incorporated in them to shorten their disintegration 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 promote the rapid disintegration of tablets in water or gastric juices and the release of the pharmaceuticals in an absorbable form.
These substances, which are also known as "disintegrators" by virtue of their effect, are capable of undergoing an increase in volume on contact with water so that, on the one hand, their own volume is increased (swelling) and, on the other hand, a pressure can be generated through the release of gases which causes the tablet to disintegrate into relatively small particles. Well-known disintegrators are, for example, carbonate/citric acid systems, although other organic acids may also be used. Swelling disintegration aids are, for example, synthetic polymers, such as polyvinyl pyrrolidone (PVP), or natural polymers and modified natural substances, such as cellulose and starch and derivatives thereof, alginates or casein derivatives.
Preferred basic 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 basic tablets contain a cellulose-based disintegrator in quantities of 0.5 to 10% by weight, preferably 3 to 7% by weight and more preferably 4 to 6% by weight. Pure cellulose has the formal empirical composition (C6H~pO5)n and, formally, is a ~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 these is preferably below 50% by weight and more preferably below 20% by weight, based on the cellulose-based disintegrator. In one particularly preferred embodiment, pure cellulose free from cellulose derivatives is used as the cellulose-based disintegrator.
The cellulose used as disintegration aid is preferably not used in fine-particle form, but is converted into a coarser form, for example by granulation or compacting, before it is added to and mixed with the premixes to be tabletted. Detergent tablets which contain granular or optionally co-granulated disintegrators are described in German patent applications DE 197 09 991 (Stefan Herzog) and DE 197 10 254 (Henkel) and in International patent application WO 98140463 (Henkel). Further particulars of the production of granulated, compacted or co-granulated cellulose disintegrators can also be found in these patent applications. The particle sizes of such disintegration aids is mostly above 200 Nm, preferably 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. 70%) undamaged. Subsequent de-aggregation of the microfine celluloses formed by hydrolysis provides the microcrystalline celluloses which have primary particle sizes of ca. 5 Nm and which can be compacted, for example, to granules with a mean particle size of 200 pm.
According to the invention, preferred processes are characterized in that the particulate premix contains a disintegration aid, preferably a cellulose-based disintegration aid, preferably in granular, co-granulated or compacted form, in quantities of 0.5 to 10% by weight, preferably in quantities of 3 to 7% by weight and more preferably in quantities of 4 to 6%
by weight, based on the premix.
In the case of the disintegration aids) also, special effects can be obtained by partly or completely omitting such substances from individual phases of multiphase tablets. For example, it is preferred to produce multiphase, more particularly multilayer, tablets of which the individual phases contain a disintegration aid in different quantities. In this way, active substances can be released from a phase under control, for example their release can be accelerated or retarded, which affords performance-related advantages.
The present invention also relates to the use of tabletting punches with projections and depressions on their contact surface, the interval between 5 the projections being between 5 and 200 Nm and the height of the projections being between 5 and 100 Nm, for reducing caking on punches.
Irrespective of the material to be tabletted, i.e. in the production of tablets in the pharmaceutical industry, food technology, battery manu facture and the manufacture of consumer goods, the use of tabletting 10 punches with the surface structures mentioned leads to distinctly reduced caking levels.
The use of the tabletting punches according to the invention has distinct and unexpected advantages above all in the case of highly adhesive premixes. Premixes such as these may be in particular detergent 15 compositions so that the present invention also relates to the use of tabletting punches with projections and depressions on their contact surface, the interval between the projections being between 5 and 200 pm and the height of the projections being between 5 and 100 pm, for the production of detergent tablets.
20 Examples To produce a tabletting punch E1 according to the invention, a tabletting punch of polytetrafluoroethylene (PTFE) is sprayed with adhesive and coated with Teflon powder (mean particle size: 11 Nm). Another tabletting punch E2 according to the invention was obtained by uniformly 25 heating the contact surface of a tabletting punch of polyvinylidene fluoride (PVDF) with a warm air unit until it became thermoplastic. A screen cloth was then pressed onto the contact surface and removed. In this way, projections with an average height of 21 pm and an average interval of 38 pm were formed. An untreated tabletting punch of PTFE was used for comparison (Comparison Example V).
Punches E1, E2 and V were installed as top punches in a Korsch eccentric press where they were used for the production of detergent tablets.
To this end, surfactant-containing granules (for composition, see Table 1 ) used as a basis for a particulate premix were produced by granulation in a 130 liter Lodige plowshare mixer. After granulation, the granules were dried for 30 minutes in a Glatt fluidized bed dryer (feed air temperature 60°C). After drying, fine particles (<0.4 mm) and coarse particles (>1.6 mm) were removed by sieving. The premix was produced by mixing the surfactant-containing granules with bleaching agent, bleach activator and other treatment components. The premix was then tabletted in the Korsch eccentric press fitted with punches E1, E2 and V to form tablets weighing 37.5 g for a diameter of 44 mm and a height of 22 mm.
The composition of the premix to be tabletted (and hence of the tablets) is shown in Table 2.

Table 1:
Composition of the surfactant granules [% by weight]
C9_~3 alkyl benzene sulfonate 17.0 C~2_~g fatty alcohol ~ 7 EO 5.3 C~2_~8 fatty alcohol sulfate 5.0 C~2-~4 alkyl (1.4)glucoside 0.8 Soap 1.6 Optical brightener 0.3 Sodium carbonate 17.0 Sodium silicate 5.6 Acrylic acid/maleic acid copolymer5.6 Zeolite A (water-free active 31.0 substance) Na hydroxyethane-1,1-diphosphonate0.8 Water, salts Balance Table 2:
Composition of the premix [% by weight]
Surfactant granules (Table 1 62.5 ) Sodium percarbonate 20.0 TAED 5.0 Foam inhibitor 3.5 Enzymes 1.5 Perfume 0.5 Wessalith~ XD (zeolite X) 2.0 Disintegration aid (cellulose) 5.0 The top punches E1, E2 and V were weighed at the beginning of the test and after the production of ten detergent tablets with a diametral fracture resistance of ca. 30 N. The weight of the caking on the punches can be directly calculated from the difference between the weights. The results of the tests are shown in Table 3:
Table 3:
Caking weight [g]
Tabletting E1 E2 V
punch PTFE punch Treated PVDF Untreated PTFE
with punch punch Teflon powder Caking [g] 0.1 0.16 0.84 It can clearly be seen that caking can be significantly reduced by the punches according to the invention with their particular surface structure.
The invention may be varied in any number of ways as would be apparent to a person skilled in the art and all obvious equivalents and the like are meant to fall within the scope of this description and claims. The description is meant to serve as a guide to interpret the claims and not to limit them unnecessarily.

Claims (40)

1. A tabletting punch, comprising projections and depressions on its contact surface, with an interval between the projections being between 5 and 200 µm and the height of the projections being between 5 and 100 µm.

2. A tabletting punch as claimed in claim 1, wherein the interval between the projections is between 6 and 180 µm.

3. A tabletting punch as claimed in claim 1, wherein the interval between the projections is 7 and 160 µm.

4. A tabletting punch as claimed in claim 1, wherein the interval between the projections is between 8 and 140 µm.

5. A tabletting punch as claimed in claim 1, wherein the interval between the projections is between 10 and 100 µm.

6. A tabletting punch as claimed in any of claims 1 or 5, wherein the height of the projections is between 6 and 90 µm.

7. A tabletting punch as claimed in claim 6, wherein the height of the projections is between 7 and 80 µm.

8. A tabletting punch as claimed in claims 6, wherein the height of the projections is between 8 and 70 µm.

9. A tabletting punch as claimed in claims 6, wherein the height of the projections is between 10 and 50 µm.

10. A tabletting punch as claimed in any of claims 1 to 9, wherein at least the projections consist of hydrophobic polymers or durably hydrophobicized materials.

11. A tabletting punch as claimed in any of claims 1 to 10, wherein at least the projections consist of a polyolefin.

12. A tabletting punch as claimed in any of claims 1 to 10, wherein at least the projections consist of a polyethylene or polypropylene.

13. A tabletting punch as claimed in any of claims 1 to 12, wherein at least the projections consist of polyvinylidene fluoride or polytetrafluoroethylene.

14. A tabletting punch as claimed in any of claims 1 to 13, wherein at least the projections consist of a polyamide, preferably PA 6, PA 12, PA 66, PA 610 or PA 612.

15. A tabletting punch as claimed in any of claims 1 to 13, wherein at least the projections consist of a polyurethane.

16. A tabletting punch as claimed in any of claims 1 to 13, wherein at least the projections consist of a glass-fiber-reinforced plastic.

17. A tablet as claimed in any of claims 1 to 13, wherein the projections consist of a glass-fiber-reinforced polytetrafluoroethylene or polyamide.

18. A process for the production of tablets by tabletting a particulate premix, wherein the tabletting punches have projections and depressions on their contact surfaces, the interval between the projections being between 5 and 200 µm and the height of the projections being between 5 and 100 µm.

19. A process as claimed in claim 18, wherein the particulate premix is a detergent composition and the tablets are detergent tablets.

20. A process as claimed in claim 19, wherein the particulate premix contains surfactant-containing granules and has a bulk density of at least 500 g/l.

21. A process as claimed in claim 19, wherein the bulk density is at least 600 g/l.

22. A process as claimed in claim 19, wherein the bulk density is at least 700 g/l.

23. A process as claimed in any of claims 20 to 22, wherein the surfactant-containing granules have particle sizes of 100 to 2000 µm.

24. A process as claimed in claim 23, wherein the particle sizes are in the range from 200 to 1800 µm.

25. A process as claimed in claim 23, wherein the particle sizes are in the range from 400 to 1600 µm.

26. A process as claimed in claim 23, wherein the particle sizes in the range from 600 to 1400 µm.

27. A process as claimed in any of claims 20 to 26, wherein the surfactant-containing granules contain anionic and/or nonionic surfactants and builders and have total surfactant contents of at least 10% by weight.

28. A process as claimed in claim 17, wherein the total surfactant contents is at least 15% by weight.

29. A process as claimed in claim 17, wherein the total surfactant contents is at least 20% by weight.

30. A process as claimed in any of claims 20 to 29, wherein the surfactant granules are mixed with other treatment components to form a tablettable premix which contains 40 to 95% by weight.

31. A process as claimed in claim 30, wherein the tablettable premix contains 45 to 85% by weight of the surfactant granules.

32. A process as claimed in claim 30, wherein the tablettable premix contains 55 to 75% by weight of the surfactant granules.

33. A process as claimed in any of claims 19 to 32, wherein the premix to be tabletted additionally contains one or more substances from the group of disintegration aids, 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.

34. A process as claimed in any of claims 19 to 33, wherein the particulate premix contains a disintegration aid, in quantities of 0.5 to 10%
by weight, based on the premix.

35. A process as claimed in claim 34, wherein the disintegration aid is a cellulose-based disintegration aid.

36. A process as claimed in claim 35, wherein the aid is in granular, co-granulated or compacted form.

37. A process as claimed in any of claims 34 to 36, wherein the quantities are 3 to 7% by weight.

38. A process as claimed in any of claims 34 to 36, wherein the quantities are 4 to 6% by weight,

39. The use of tabletting punches with projections and depressions on their contact surfaces, wherein the projection intervals are between 5 and 200 µm and the height of the projections is between 5 and 100 µm, for reducing caking on punches.

40. The use of tabletting punches with projections and depressions on their contact surfaces, wherein the projection intervals are between 5 and 200 µm and the height of the projections is between 5 and 100 µm, for the production of detergent tablets.