CA2306383A1 - Performance-enhanced dishwasher tablets - Google Patents

Abstract

Detergent tablets with rapid and relatively long-lasting enzyme release and hence improved enzyme performance contain a region of one or more coating material(s) with a melting point above 30°C, one or more liquid enzyme preparation(s) dispersed in the coating material(s) and optionally other auxiliaries and/or active substances.

Description

Performance-enhanced Dishwasher Tablets Field of the Invention This invention relates generally to enzyme-containing shaped bodies with detersive properties and, more particularly, to performance-enhanced multiphase detergent tablets in which advantages in regard to detersive performance are obtained through division into several phases. Detergent tablets such as these include, in particular, dishwasher detergent tablets.
Background of the Invention Dishwasher detergents are widely described in the prior art literature and are enjoying increasing popularity among consumers. Tabletted detergents have a number of advantages over powder-form products.
They are easier to dose and handle and, by virtue of their compact structure, have advantages in regard to storage and transportation.
Accordingly, there is an extremely broad prior art on detergent tablets which is also reflected in extensive patent literature. At a very early stage, developers of tablet-form products came up with the idea of releasing certain ingredients into the wash cycle under defined conditions through differently composed parts or regions of the tablets in order in this way to improve the outcome of the cleaning process. Besides the core/jacket tablets and ring/core tablets known for some time in the pharmaceutical industry, multilayer tablets in particular have been successfully used and are now available for many aspects of washing and cleaning or hygiene.
Multiphase lavatory cleaning tablets are described, for example, in European patent application EP 0 055 100 (Jeyes Group). This document discloses toilet cleaning blocks which comprise a block of a slowly dissolving cleaning composition in which a bleaching tablet is embedded.
The document in question also discloses various embodiments of multiphase tablets. According to the teaching of EP 0 055 100, the tablets are produced either by introducing a bleaching tablet into a mold and coating the tablet with the cleaning composition or by casting part of the cleaning composition into the mold, introducing the bleaching tablet and, optionally, overcoating with more cleaning composition. Enzymes, machine dishwashing and other special embodiments of the present invention are neither mentioned nor suggested in this document.
EP 481 547 (Unilever) describes multiphase detergent tablets which are intended for use in dishwashing machines. These tablets are core/jacket tablets and are produced by compressing the ingredients in stages. First, a bleaching composition is compressed to a form a shaped body which is introduced into a die half-filled with a polymer composition which is then filled with more polymer composition and compressed to form a bleaching tablet with a polymer jacket. The procedure is then repeated with an alkaline detergent composition so that a three-phase tablet is obtained. Enzymes and enzyme performance are not mentioned in this document.
The controlled release aspect of ingredients has been, and is still being, intensively investigated inter alia in the field of detergents, so that several publications are also available on the subject. So far as detergent tablets are concerned, most publications suggest the accelerated release of certain regions of the tablet by disintegration aids or effervescent systems whereas the slower release of individual ingredients, for example by coating or by the selective delay of dissolution, tends to assume a lesser role.
Earlier German patent application DE 198 51 426.3 (Henkel KGaA) describes a process for the production of multiphase detergent tablets in which a particulate premix is compressed to form tablets comprising a cavity which is subsequently filled with a separately prepared melt suspension or emulsion of a coating material and one or more active substances) dispersed or suspended therein. The coating materials mentioned in this document include paraffins and polyethylene glycols while the active substances mentioned include enzymes, bleaching agents, bleach activators, surfactants, corrosion inhibitors, scale inhibitors, co-builders and/or perfumes. This document does not mention liquid enzyme preparations and does not disclose any information on the improvement of enzyme performance in dishwasher detergents.
The problem addressed by the present invention was to provide dishwasher detergent tablets which would provide for the controlled release of certain ingredients at predeterminable times in the wash cycle and which, on the other hand, would be distinguished by excellent stability in storage and in transit and would perform better than conventional products in various fields of application. More particularly, the tablets to be provided by the invention would be superior to conventional tablets above all in their stability in storage and in enzyme performance.
Summary of the Invention It has now been found that detergent tablets with the requisite properties can be obtained in a flexible and simple manner by processing liquid enzyme preparations with coating materials and optionally carrier materials and/or other ingredients to form melt dispersions which are then applied to or introduced into the tablet either directly or after forming/shaping.
The present invention relates to dishwasher detergent tablets containing builders, enzymes and optionally other detergent ingredients, characterized in that, in or on a basic tablet, a region of the tablet consists of a) one or more coating materials with a melting point above 30°C, b) one or more liquid enzyme preparations) dispersed in the coating materials) and c) optionally other active substances and/or auxiliaries.
According to the present invention, commercially available liquid enzyme preparations are embedded in a matrix or coating material(s), optionally together with other auxiliaries and/or active substances, and form a region of the tablet. The enzymes are released from this matrix on the one hand more quickly and, on the other hand, surprisingly over a longer period so that a rapid and continuing release of the enzymes is achieved.
By adopting the procedure according to the invention, the maximum enzyme activity is achieved at a much earlier stage in the wash cycle, enzyme activity remaining at a fairly high level throughout the remainder of the wash cycle.
Detailed Description of the Invention In the context of the present invention, the term "region"
characterizes that part of the tablet as a whole which contains the mixture of coating material, liquid enzyme preparation and optional active substances and auxiliaries. In the most simple case, this region may assume the form of a layer although it may also be, for example, the filled part of a cavity. The term "region" is not confined to one region; on the contrary, the substances mentioned may also be distributed throughout the tablet in several regions.
The term "basic tablet" in the context of the present invention characterizes the tablet produced in known manner by tabletting which does not yet contain the "region". In other words, the basic tablets) is/are those parts) of the tablet as a whole which is/are not (a) "region(s)" in the context of the invention. In preferred embodiments of the present invention, the basic tablet is produced first and the region is applied to or introduced into the basic tablet in another process step. The resulting product is referred to hereinafter as a tablet.
The enzymes most commonly used in detergents include lipases, cellulases, amylases and proteases. In addition, hemicellulases, peroxi-dases and pectinases are used in special products. Proteases, amylases and lipases are of particular importance in dishwasher detergents. The enzymes are normally produced in a granulated an encapsulated form for use in powder products and are added to the detergent in that form. In water-containing liquid detergents, these granulated and encapsulated enzymes would partly dissolve so that, in general, liquid enzyme 5 concentrates are preferably used in their case. Such liquid enzyme concentrates are based either homogeneously on propylene glycol/water or heterogeneously on a slurry or are present in microencapsulated form. The use of liquid enzyme products in solid detergents has never been described before.
Preferred liquid proteases are, for example, Savinase~ L, Durazym~ L, Esperase~ L and Everlase~ (Novo Nordisk); Optimase~ L, Purafect~ L, Purafect~ OX L, Properase~ L (Genencor International) and BLAP~ L (Biozym GmbH). Preferred amylases are Termamyl~ L, Duramyl~ L and BAN~ (Novo Nordisk) and Maxamyl~ WL and Purafect~
HPAm L (Genencor International). Preferred lipases are Lipolase~ L, Lipolase~ ultra L and Lipoprime~ L (Novo Nordisk) and Lipomax~ L
(Genencor International).
The Novo Nordisk products SL and LCC, for example, may be used as slurries or microencapsulated liquid products. The commercially available liquid enzyme preparations mentioned contain, for example, 20 to 90% by weight of propylene glycol or mixtures of propylene glycol and water. According to the present invention, preferred detergent tablets are characterized in that the region contains one or more liquid amylase preparations and/or one or more liquid protease preparations.
The region of the tablet may contain the ingredients mentioned in varying quantities, the expert being unrestricted in his freedom of formulation. In the usual field of application, detergent tablets where the region of the tablet consists of a) 40 to 99.5% by weight, preferably 50 to 97.5% by weight, more preferably 60 to 95% by weight and most preferably 70 to 90% by weight of one or more coating materials) with a melting point above 30°C, b) 0.5 to 60% by weight, preferably 1 to 40% by weight, more preferably 2.5 to 30% by weight and most preferably 5 to 25% by weight of one or more liquid enzyme preparations) dispersed in the coating materials) and c) 0 to 20% by weight, preferably 0 to 15% by weight, more preferably 0 to 10% by weight and most preferably 0 to 5% by weight of optionally other auxiliaries and/or active substances, based on the region, have been found to be preferable.
As mentioned above, the region may assume many different forms.
In the interests of process economy at the production level, it is preferred in accordance with the invention for the region to assume the form of an insert, a core or a layer.
Tablets according to the invention contain liquid enzyme preparations encapsulated in coating materials in one (or more) region(s).
The basic tablet contains other important ingredients of detergents, more especially builders.
The dishwasher detergents according to the invention may contain any of the builders typically used in detergents, i.e. in particular zeolites, silicates, carbonates, organic co-builders and - as an important builder in dishwasher detergents - also phosphates.
Suitable crystalline layered sodium silicates correspond to the general formula NaMSiXOZX+~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 layered silicates such as these are described, for example, in European patent application EP-A-0 164 514. Preferred crystalline layered silicates corresponding to the above formula are those in which M is sodium and x assumes the value 2 or 3. Both Vii- and 8-sodium disilicates Na2Si205y H20 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.
Suitable zeolites have a mean particle size of less than 10 ~,m (volume distribution, as measured by the Coulter Counter Method) and contain preferably 18 to 22% by weight and more preferably 20 to 22% by weight of bound water.
The generally known phosphates may of course also be used as builders providing their use should not be avoided on ecological grounds.
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)~ 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°, are converted into the weakly acidic diphosphate (disodium hydrogen diphosphate, Na2HZP20~) and, at higher temperatures, into sodium trimetaphosphate (Na3P309) 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), Na2HP04, 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 moles (density 1.68 gcm-3, melting point 48° with loss of 5 H20) and 12 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 Na4PZ0~. Disodium hydrogen phosphate is prepared by neutralization of phosphoric acid with soda solution using phenol-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~ and a melting point 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~ 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 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.

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), Na4P20~, exists 5 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. Na4P20~ is formed when disodium phosphate is heated to >200° or by reacting 10 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 diahosahate (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)-O]~-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, K5P3O~p (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.
The dishwasher tablets according to the invention are preferably characterized in that the basic tablet contains builders in quantities of 20 to 80% by weight, preferably in quantities of 25 to 75% by weight and more preferably in quantities of 30 to 70% by weight, based on the basic tablet.
Organic cobuilders suitable for use in the dishwasher detergents according to the invention are, in particular, polycarboxylates/polycarboxylic acids, polymeric polycarboxylates, aspartic acid, polyacetals, 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 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 their 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 builders are polymeric polycarboxylates such as, 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.
The (co)polymeric polycarboxylates may be used either in powder form or in the form of an aqueous solution. The content of (co)polymeric polycarboxylates in the detergent is preferably from 0.5 to 20% by weight and more preferably from 3 to 10% by weight.
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 three 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 suitable organic builders are dextrins, for example oligomers or polymers of carbohydrates which may be obtained by partial hydrolysis 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/mol. A polysaccharide with a dextrose equivalent (DE) of 0.5 to 40 and, more particularly, 2 to 30 is preferred, the DE being an accepted 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.
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-0 472 042 and EP-A-0 542 496 and from International patent applications WO 92118542, WO 93108251, WO 93116110, WO 94/28030, WO 95107303, WO 95!12619 and WO 95/20608. 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 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 5 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 10 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-A-95/20029.
Another class of substances with co-builder properties are the phosphonates, more particularly hydroxyalkane and aminoalkane phos 15 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.

Besides the builders, substances from the groups of surfactants, bleaching agents, bleach activators, corrosion inhibitors and dyes and perfumes are important ingredients of detergents. Important representatives of the classes of compounds mentioned are described in the following.
Normally, the only surfactants used in dishwasher detergents are low-foaming nonionic surfactants. Representatives from the groups of anionic, cationic or amphoteric surfactants are of lesser importance. In one particularly preferred embodiment, the dishwasher detergent tablets according to the invention contain nonionic surfactants.
In particularly preferred embodiments of the present invention, the detergent tablets according to the invention contain nonionic surfactants, more particularly nonionic surfactants from the group of alkoxylated alcohols. 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 radical may be linear or, preferably, methyl-branched in the 2-position or may contain linear and methyl-branched radicals in the form of the mixtures typically present in oxoalcohol radicals. However, alcohol ethoxylates containing linear radicals of alcohols of native origin with 12 to 18 carbon atoms, for example coconut oil, palm oil, 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 C~2_~8 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.
Suitable other nonionic surfactants are alkyl glycosides with the general formula RO(G)X where R is a primary, linear or methyl-branched, more particularly 2-methyl-branched, aliphatic radical containing 8 to 22 and preferably 12 to 18 carbon atoms and G stands for a glycose unit containing 5 or 6 carbon atoms, preferably glucose. The degree of oligomerization x, which indicates the distribution of monoglycosides and oligoglycosides, is a number of 1 to 10 and preferably 1.2 to 1.4.
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 581217598 or which are preferably produced by the process described in International patent application WO-A-90113533.
Nonionic surfactants of the amine oxide type, for example N
coconutalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxy ethylamine 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~.~ 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.
Besides pure nonionic surfactants, other substances from the group of ionic surfactants, for example anionic or cationic surfactants, may of course also be present in the dishwasher detergents according to the invention.
According to the invention, preferred detergent tablets contain surfactant(s), preferably nonionic surfactant(s), in quantities of 0.5 to 10%
by weight, preferably in quantities of 0.75 to 7.5% by weight and more preferably in quantities of 1.0 to 5% by weight, based on the detergent as a whole.
Among the compounds yielding H202 in water which serve as bleaching agents, sodium perborate tetrahydrate and sodium perborate monohydrate are particularly important. Other useful bleaching agents are, for example, sodium percarbonate, peroxypyrophosphates, citrate perhy-drates and H202-yielding peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or diperdodecane dioic acid. Detergents according to the invention may also contain bleaching agents from the group of organic bleaching agents.
Typical organic bleaching agents are the 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, E-phthalimidoperoxycaproic acid [phthaloiminoperoxyhexanoic acid (PAP)], o-carboxybenzamidoperoxy-caproic acid, N-nonenylamidoperadipic acid and N-nonenylamido-persuccinates. 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-amino-percaproic acid).
Other suitable bleaching agents in the dishwasher tablets acording to the invention 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, dibromoisocyanuric acid and/or dichloro-5 isocyanuric 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.
The bleaching agents are normally used in dishwasher detergents in quantities of 1 to 30% by weight, preferably in quantities of 2.5 to 20% by 10 weight and more preferably in quantities of 5 to 15% by weight, based on the detergent. In the context of the present invention, the quantities mentioned are based on the weight of the basic tablet.
Bleach activators which support the effect of the bleaching agents can also be part of the basic tablet. Known bleach activators are 15 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 tetraacetyl hexylenediamine (TAHD) and also pentaacetyl glucose (PAG), 1,5-diacetyl-2,2-20 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 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 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 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 and mannitol and the 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 are also preferably used. Combinations of conventional bleach activators may also be used. The bleach activators are normally used in dishwasher detergents in quantities of 0.1 to 20% by weight, preferably in quantities of 0.25 to 15% by weight and most preferably in quantities of 1 to 10% by weight, based on the detergent as a whole. In the context of the invention, the quantities mentioned are based on the weight of the basic tablet.
In addition to or instead of the conventional bleach activators mentioned above, so-called bleach catalysts may also be incorporated in the basic tablet. 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.
The basic tablet may of course also contain enzymes so that a conventional enzyme release and effect is achieved and is supported by the enzyme release and effect from the region according to the invention.
Corresponding detergent tablets have as it were a "booster enzyme effect".
The enzymes optionally used in the basic tablet are preferably commercially available solid enzyme preparations.
Suitable enzymes in the basic tablets are, in particular, 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. 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 shell-forming substances 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. Preferred detergent tablets according to the invention are characterized in that the basic tablet contains protease and/or amylase.
By virtue of the fact that the detergent tablets according to the invention may contain the enzymes) in two basically different regions, it is possible to provide tablets characterized by a very precisely defined enzyme release and effect. The following Table provides an overview of possible enzyme distributions in detergent tablets according to the invention:

Basic tablet - Coatingmaterial/enzyme region - Amylase - Protease - Lipase - Amylase + Protease - Amylase + Lipase - Protease + Lipase - Amylase + Protease +
Lipase Amylase Amylase Protease Amylase Amylase + Protease Amylase Amylase Protease Protease Protease Amylase + Protease Protease Amylase Amylase + Protease Protease Amylase + Protease Amylase + Protease Amylase + Protease Lipase Amylase Amylase + Lipase Amylase Protease + Lipase Amylase Amylase + Protease + LipaseAmylase Lipase Protease Amylase + Lipase Protease Protease + Lipase Protease Amylase + Protease + LipaseProtease Lipase Amylase + Protease Amylase + Lipase Amylase + Protease Protease + Lipase Amylase + Protease Amylase + Protease + LipaseAmylase + Protease Dyes and perfumes may be added to the dishwasher detergents according to the invention both in the basic tablet and in the region 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 compounds of the ester type are, for example, benzyl acetate, phenoxyethyl isobutyrate, p-tert.butyl cyclohexyl acetate, linalyl acetate, dimethyl benzyl carbinyl acetate, phenyl ethyl acetate, linalyl benzoate, benzyl formate, ethyl methyl phenyl glycinate, 5 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, citronellyloxyacetaldehyde, cyclamen aldehyde, hydroxy-citronellal, lilial and bourgeonal; the ketones include, for example, the 10 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 15 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 20 blossom oil, neroli oil, orange peel oil and sandalwood oil.
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.
In order to improve their aesthetic impression, the detergents 25 according to the invention (or parts thereof) may be colored with suitable dyes. Preferred dyes, which are not difficult for the expert to choose, have high stability in storage, are not affected by the other ingredients of the detergents or by light and do not have any pronounced substantivity for the substrates treated with the detergents, such as glass, ceramics or plastic tableware, so as not to color them.

To protect the tableware or the machine itself, the detergent tablets according to the invention may contain corrosion inhibitors, especially in the basic tablet, 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, alkylaminotriazoles 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, hydroxy-hydroquinone, gallic acid, phloroglucinol, 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.
The production of the basic tablet is not confined to the tabletting of just one particulate premix. On the contrary, the basic tablet may also be produced in known manner in the form of a multilayer tablet by preparing two or more premixes and compressing them onto one another. In this case, the premix introduced first is only lightly precompressed, if at all, so as to obtain a smooth upper surface running parallel to the tablet base.
After introduction of the second premix, the two pemixes are compressed to form the final tablet. In the case of tablets with three or more layers, the addition of each premix is followed by precompression before the tablet is finally formed after addition of the last premix.
In view of the increasing outlay on equipment, tablets with at most two layers are preferred in practice, i.e. preferred detergent tablets are characterized in that the basic tablet is a two-layer tablet. With this intermediate step alone, advantages can be obtained in the process according to the invention from the allocation of certain ingredients to the individual layers.
For example, preferred detergent tablets are characterized in that one layer of the basic tablet contains one or more bleaching agents while the other layer contains one or more enzymes. Not only can this separation of bleaching agent and enzymes afford advantages, the separation of bleaching agents and optional bleach activators can also be of advantage so that detergent tablets according to the invention where one layer of the basic tablet contains one or more bleaching agents and the other layer contains one or more bleach activators are preferred.
Now that the basic tablet has been described, the other ingredients of the region - of which the coating material is complusory along with the liquid enzyme preparations - will be described in the following. Preferred coating materials of the region have a melting range of 45°C to 75°C. This melting range guarantees an advantageous enzyme release in standard dishwasher programs. In one advantageous embodiment of the invention, the coating material is water-soluble.
Particularly preferred detergent tablets are characterized in that the coating material of the region contains at least one substance from the group of polyethylene glycols (PEGs) and/or polypropylene glycols (PPGs), polyethylene glycols with molecular weights of 1500 to 36,000 being preferred, those with molecular weights of 2000 to 6000 being particularly preferred and those with molecular weights of 3000 to 5000 being most particularly preferred.

Detergent tablets containing propylene glycols (PPGs) and/or polyethylene glycols (PEGs) as sole coating material in the region are particularly preferred. Polypropylene glycols (PPGs) suitable for use in accordance with the invention are polymers of propylene glycol corresponding to general formula III:
H-(O- i H-CH2)"-OH (III) where n may assume a value of 10 to 2000. Preferred PPGs have molecular weights of 1000 to 10,000 corresponding to values for n of 17 to about 170.
Polyethylene glycols (PEGs) preferably used in accordance with the invention are polymers of ethylene glycol corresponding to general formula (IV):
H-(O-CH2-CH2)"-OH (IV) in which m may assume a value of 20 to about 1000. The preferred molecular weight ranges mentioned above correspond to preferred ranges for the value of n in formula II of about 30 to about 820 (exactly: 34 to 818), more preferably of about 40 to about 150 (exactly: 45 to 136) and, most preferably, of about 70 to about 120 (exactly: 68 to 113).
Besides the essential ingredients (coating material and liquid enzyme preparation), the region may contain other active substances and/or auxiliaries, for example those from the groups of anti-sedimenting agents, anti-settling agents, anti-floating agents, thixotropicizing agents and dispersants. Thus, certain detergent tablets according to the invention may contain other auxiliaries from the group of anti-sedimenting agents, anti-settling agents, anti-floating agents, thixotropicizing agents and dispersants in the region in quantities of 0.5 to 8.0% by weight, preferably in quantities of 1.0 to 5.0% by weight and more preferably in quantities of 1.5 to 3.0% by weight, based on the region.
According to the invention, the region may also contain emulsifiers from the group of fatty alcohols, fatty acids, polyglycerol esters and/or polyoxyalkylene siloxanes in quantities of 1 to 20% by weight, preferably in quantities of 2 to 15% by weight and more preferably in quantities of 2.5 to 10% by weight, based on the region.
However, preferred detergent tablets are characterized in that, apart from the coating materials) and the constituents of the liquid enzyme preparations, they contain no other ingredients.
The detergent tablets according to the invention can be produced in various ways. For example, it is possible by tabletting methods known per se to produce tablets with a cavity which is filled with a melt dispersion of coating material, liquid enzyme preparations) and optional ingredients.
Bull's-eye and recess can be produced in this way. The melt dispersion may of course also be applied to one side or to the entire surface of the previously compressed tablet using coating techniques known to the expert, such as spraying or dipping the tablet into the melt dispersion. The basic tablet may also be transferred to a die and the melt dispersion may be poured onto one side of the tablet where it solidifies in the die.
Multilayer tablets where the region assumes the form of a layer can be produced in this way.
Another route is to subject the melt dispersion to forming/shaping in the solidification range of the melt so that particles with the composition of the melt dispersion are obtained. These particles may be incorporated in the premixes to be tabletted and, in this way, form a plurality of regions uniformly distributed throughout the tablet. However, the particles - which may be in the form of flakes, beads, strands, etc. - may also be used as a premix of which the compression by multilayer tabletting known per se forms a layer with the same composition as the melt dispersion.
The present invention is also concerned with both the methods outlined above for producing the detergent tablets according to the invention, i.e. the present invention also relates to a process for the 5 production of multiphase detergent tablets which is characterized by the following steps:
a) tabletting a particulate premix in known manner to form cavity tablets, b) preparing a melt dispersion from a coating material with a melting point above 30°C and one or more liquid enzyme preparations) dispersed 10 therein, c) filling the tablets from step a) with the melt dispersion from step b) at temperatures above the melting point of the coating material, d) cooling and optionally aftertreating the filled detergent tablets.
The present invention also relates to the second route, i.e. to a 15 process for the production of multiphase detergent tablets which is characterized by the following steps:
a) preparing a melt dispersion from a coating material with a melting point above 30°C and one or more liquid enzyme preparations) dispersed therein, 20 b) forming/shaping the melt dispersion in the solidification range of the melt to form a particulate composition, c) optionally mixing the particles formed in step b) with other particulate detergent ingredients and d) compressing the premixes formed in step b) or c) to form tablets or 25 tablet regions.
In the first process according to the invention, a melt dispersion of the above-described ingredients of the region is prepared in step b). In the second process according to the invention, this is done in process step a).
So far as preferred quantities and certain substances of the coating 30 material and the liquid enzyme preparations are concerned, reference may be made to the foregoing observations on the detergent tablets according to the invention. The foregoing observations also apply in regard to the composition of the basic tablet in the first process according to the invention.
Thus, first process variants according to the invention are charac-terized in that the premix tabletted in step a) contains builders in quantities of 20 to 80% by weight, preferably in quantities of 25 to 75% by weight and more preferably in quantities of 30 to 70% by weight, based on the premix.
In another preferred embodiment of the first process, the particulate premix tabletted in step a) contains surfactant(s), preferably nonionic surfactant(s), in quantities of 0.5 to 10% by weight, preferably in quantities of 0.75 to 7.5% by weight and more preferably in quantities of 1.0 to 5% by weight, based on the premix.
As described above in reference to the basic tablet, the premix may be made up of various substances. Irrespective of the composition of the premixes to be tabletted in step a), physical parameters of the premixes may be selected so that advantageous tablet properties are obtained.
Thus, in preferred variants of the first process according to the invention, the particulate premixes tabletted in step a) have bulk densities above 600 g/I, preferably above 700 g/I and more preferably above 800 g/I.
The particle size in the premixes to be tabletted may also be adjusted to obtain advantageous tablet properties. In preferred variants of the first process according to the invention, the particulate premix tabletted in step a) has a particle size distribution in which less than 10% by weight, preferably less than 7.5% by weight and more preferably less than 5% by weight of the particles are larger than 1600 Nm or smaller than 200 Nm.
Narrower particle size distributions are more preferred. Particularly advantageous process variants are characterized in that the particulate premix tabletted in step a) has a particle size distribution where more than 30% by weight, preferably more than 40% by weight and more preferably more than 50% by weight of the particles are between 600 and 1000 Nm in size.
Step a) of the first process according to the invention is not confined to the tabletting of just one particulate premix. On the contrary, process step a) may also be augmented to the extent that multilayer tablets are produced in known manner by preparing two or more premixes which are compressed onto one another. In this case, the first premix introduced is lightly precompressed in order to obtain a smooth surface running parallel to the base of the tablet. After the second premix has been introduced, the two premixes are tabletted to form the final tablet. In the case of tablets with three or more layers, each addition of premix is followed by precom-pression before the final tablet is formed after addition of the last premix.
The above-described cavity in the basic tablet is preferably a recess so that preferred embodiments of the first process according to the invention are characterized in that multilayer tablets with a recess are produced in known manner in step a) by compressing several different particulate premixes onto one another.
Similarly to the foregoing observations, this variant is also preferably carried out by processes where finro-layer recess tablets are produced in step a) by compressing onto one another two different particulate premixes of which one contains one or more bleaching agents and the other contains one or more enzymes. Likewise, preference is also attributed to processes where two-layer recess tablets are produced in step a) by compressing onto one another two different particulate premixes of which one contains one or more bleaching agents and the other one or more bleach activators.
Here, too, preferred processes are characterized in that the basic tablet produced in step a) contains protease and/or amylase.
Irrespective of whether the melt dispersion is introduced into a cavity of a tablet prepared in advance (first process variant) or whether the dispersion is subjected to forming/shaping in the solidification range, preferred processes according to the invention are characterized in that the melt dispersion prepared in step b) consists of 40 to 99.5% by weight, preferably 50 to 97.5% by weight, more preferably 60 to 95% by weight and most preferably 70 to 90% by weight of one or more coating materials) with a melting point above 30°C, 0.5 to 60% by weight, preferably 1 to 40%
by weight, more preferably 2.5 to 30% by weight and most preferably 5 to 25% by weight of one or more liquid enzyme preparations) dispersed in the coating materials) and 0 to 20% by weight, preferably 0 to 15% by weight, more preferably 0 to 10% by weight and most preferably 0 to 5% by weight of optionally other auxiliaries and/or active substances.
In the case of the second process according to the invention, the shaping/forming step b) is carried out by granulation, compacting, pelleting, extrusion or tabletting.
The granules, compactates, pellets, prills, extrudates, beads, flakes, tablets, etc. obtained in this way can be compressed to form relatively large regions by conventional tabletting processes. Tabletting may be carried out either directly or after mixing with other particles, for example other powder-form or granular detergent ingredients. Accordingly, in other embodiments of the second process according to the invention, the particles formed in step b) are mixed with other particulate detergent ingredients to form a premix which is tabletted to form a single-layer tablet.
However, the region is preferably a continuous region, i.e. is not made up of numerous relatively small regions. In preferred embodiments of the second process according to the invention, therefore, the particles formed in step b) are used without other additives as a premix for the production of a two-layer tablet by methods known per se.
As mentioned in the foregoing, preferred variants - irrespective of the nature of the process according to the invention - are characterized in that the coating material of the melt dispersion contains at least one substance from the group of polyethylene glycols (PEGs) and/or polypro-pylene glycols (PPGs), polyethylene glycols with molecular weights of 1500 to 36,000 being preferred, those with molecular weights of 2000 to 6000 being particularly preferred and those with molecular weights of 3000 to 5000 being most particularly preferred, and in that the melt dispersion contains one or more liquid amylase preparations and/or one or more liquid protease preparations.
By virtue of the region of coating material and liquid enzyme preparation present in them, the detergent tablets according to the invention have distinct advantages over hitherto known products where they are used in dishwashing machines. Accordingly, the present invention also relates to the use of solidified melt dispersions of a) one or more coating materials) with a melting point above 30°C, b) one or more liquid enzyme preparations) dispersed in the coating materials) and c) optionally other auxiliaries and/or active substances in detergent tablets for dishwashing machines.
The use of enzymes dispersed in polyethylene glycols with molecular weights in the range from 1500 to 36,000, preferably in the range from 2000 to 6000 and more preferably in the range from 3000 to 5000 in dishwasher tablets is particularly preferred.
As the following Examples show, the region releases the enzymes more quickly and for longer periods than hitherto known detergent tablets.
Accordingly, the present invention also relates to the use of solidified melt dispersions of a) one or more coating materials) with a melting point above 30°C, b) one or more liquid enzyme preparations) dispersed in the coating materials) and c) optionally other auxiliaries and/or active substances for the rapid and long-lasting release of enzymes from detergent tablets containing these solidified dispersions.

Embodiments of the present invention are described in the following specific examples which are not to be construed as limiting.
Examples 5 Production of recess tablets Two rectangular tablets differing in composition with a semi-elliptical recess were produced by tabletting two different premixes. The composi-tion (in % by weight, based on the particular premix) of the two premixes and hence of the two different tablets is shown in the following Table:
Premix 1 Premix 2 Protease-containingProtease-free tablet tablet Sodium carbonate 16.5 18.0 Sodium tripolyphosphate50.0 50.0 Sodium disilicate 5.0 5.0 Polycarboxylate 5.0 5.0 HEDP* 1.0 1.0 Sodium perborate 10.0 10.0 Tetraacetyl ethylenediamine2.0 2.0 C~2 fatty alcohol + 2.0 2.0 Protease (BLAP~ 200 1.5 -S) Amylase (Duramyl~ 60 2.0 2.0 T) Balance** 5.0 5.0 * Hydroxyethane-1,1-diphosphonic acid, tetrasodium salt ** Perfume, dyes, salts, binder In addition, melt dispersions with the following composition were prepared:
Melt dispersion Melt dispersion Protease (BLAP~ S 260 15.0 -LD) Amylase (Termamyl~ 300 - 15.0 L) PEG 4000 85.0 85.0 The protease-free basic tablet 2 was filled with melt dispersion 1 and gave the tablet E1 according to the invention, the basic tablet weighing 24 g before filling and 25 g after filling. Similarly, the protease-containing basic tablet 1 was filled with melt dispersion 1 which gave tablet E2 according to the invention.
The cleaning performance of tablets E1 and E2 according to the invention was evaluated against the unfilled basic tablets 2 (C1) and 1 (C2). To this end, soiled tableware was cleaned in the main wash cycle of a 55°C program (water hardness 16°d) of a Miele G 590 with universal program. The following Table shows the cleaning performance of the individual tablets against various protease-sensitive soils. It is pointed out in this connection that the unfilled tablet C1 is protease-free while the unfilled tablet C2 contains protease in the basic tablet. Tablet E1 according to the invention only contains the protease in the cast-in core (quantitatively less protease activity than C2) whereas tablet E2 according to the invention contains protease both in the basic tablet and in the core.
The cleaning performance of the detergents against the soils was visually evaluated by experts and scored on a scale of 0 to 10 where a score of "0"
signifies no cleaning while a score of "10" signifies complete removal of the stains. The results of the cleaning tests are set out in the following Table.
In the interests of clarity, the presence of protease in the basic tablet is indicated by the letter "B" while the presence of protease in the "enzyme core" is indicated by the letter "K".
Protease in .I. g !( I( +
B

Minced meat on glass (burnt-on)- 8.0 - 9.0 Minced meat on china (dried-on)- 9.0 - 10.0 Egg yolk (dried-on) 1.0 8.9 8.0 10.0 -Egg/milk (dried-on) 1.0 10.0 10.0 10.0 In order further to illustrate the "booster effect" of the enzyme core, tablets C2 and E2 were compared in a 40°C program:

Minced meat on glass (burnt-on)5.2 6.0 Minced meat on china (dried-on)5.7 6.5 Egg yolk (dried-on) 3.2 5.8 Egg/milk (dried-on) 5.0 8.8 The results show that the presence of protease on its own in an "enzyme core" is equivalent to a multiple dose of protease in the basic tablet against certain soils (comparison E1-C2). Here, the same performance is achieved with less protease. If the protease is used both in the basic tablet and in the "enzyme core", cleaning performance against all soils can be distinctly improved, even in low-temperature programs.
Effectiveness against amylase-sensitive soils can be similarly demonstrated. To this end, basic tablet 2 was filled with melt dispersion 2 (E3) and compared for performance with an unfilled basic tablet 2 (C3).

Oat flakes (dried-on)7.2 8.2 8.4 9.5 Rice starch (dried-on)2.8 - 8.3 -Starch mix (dried-on)5.7 10.0 9.1 10.0 Spaghetti 7.0 - 7.6 -It can again be seen that the cleaning performance against all soils is distinctly improved, even in low-temperature programs, where amylase is used both in the basic tablet and in the "enzyme core".
Release kinetics In an enzyme release test, the protease-containing basic tablet 1 (C4) was compared with a protease-free tablet 2 which contained the same quantity of protease in the form of an "enzyme core" with the composition mentioned above (85% PEG, 15% protease) (E4). Both tablets were subjected to the main wash cycle of a dishwashing machine, enzyme activity being measured as a function of time. The results are set out in the following Table:
Time [mins.] 2.5 5 6.75 7.5 10 15 20 25 Protease activity 2 5 10 25 100 60 10 6 Protease activity 0 60 100 80 70 70 66 50 The Table shows that the tablet according to the invention reaches its maximum activity after only 6.75 minutes while the comparison tablet takes 10 minutes. In addition, enzyme activity in the wash liquor remains at a high level throughout the main wash cycle whereas, in the Comparison Example, it falls dramatically only shortly after the maximum.

Claims (16)

1. A detergent tablet for dishwashing machines containing builders, enzymes and optionally other detergent ingredients, wherein, in or on a basic tablet, a region of the tablet consists of a) one or more coating materials with a melting point above 30°C, b) one or more liquid enzyme preparation(s) dispersed in the coating material(s) and c) optionally other active substances and/or auxiliaries.

2. A detergent tablet as claimed in claim 1, wherein the region of the tablet consists of - based on the region a) 40 to 99.5% by weight of one or more coating material(s) with a melting point above 30°C, b) 0.5 to 60% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s) and c) 0 to 20% by weight optionally of other auxiliaries and/or active substances.

3. A detergent tablet as claimed in claim 2, wherein the region of the tablet consists of 50 to 97.5% by weight of one or more coating material(s) with a melting point above 30°C.

4. A detergent tablet as claimed in claim 3, wherein the region of the tablet consists of 60 to 95% by weight of one or more coating material(s) with a melting point above 30°C.

5. A detergent tablet as claimed in claim 4, wherein the region of the tablet consists of 70 to 90% by weight of one or more coating material(s) with a melting point above 30°C.

6. A detergent tablet as claimed in claim 2, wherein the region of the tablet consists of 1 to 40% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).

7. A detergent tablet as claimed in claim 6, wherein the region of the tablet consists of 2.5 to 30% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).
7. A detergent tablet as claimed in claim 6, wherein the region of the tablet consists of 2.5 to 30% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).

8. A detergent tablet as claimed in claim 7, wherein the region of the tablet consists of 5 to 25% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).

9. A detergent tablet as claimed in claim 2, wherein the region of the tablet consists of 0 to 15% by weight optionally of other auxiliaries and/or active substances.

10. A detergent tablet as claimed in claim 9, wherein the region of the tablet consists of 0 to 10% by weight optionally of other auxiliaries and/or active substances.

11. A detergent tablet as claimed in claim 10, wherein the region of the tablet consists of 0 to 5% by weight optionally of other auxiliaries and/or active substances.

12. A detergent tablet as claimed in any of claims 1 to 11, wherein the region assumes the form of an insert, a core or a layer.

13. A detergent tablet as claimed in any of claims 1 to 12, wherein the basic tablet contains builders in quantities of 20 to 80% by weight based on the basic tablet.

14. A detergent tablet as claimed in claim 13, wherein the basic tablet contains builders in quantities of 25 to 75% by weight based on the basic tablet.

15. A detergent tablet as claimed in claim 14, wherein the basic tablet contains builders in quantities of 30 to 70% by weight based on the basic tablet.

16. A detergent tablet as claimed in any of claims 1 to 15, wherein the basic tablet contains surfactant(s) in quantities of 0.5 to 10% by weight based on the basic tablet.

present in quantities of 1.0 to 5% by weight.
19. A detergent tablet as claimed in any of claims 16 to 18, wherein said surfactant(s) is a nonionic surfactant.
20. A detergent tablet as claimed in any of claims 1 to 19, wherein the basic tablet is a two-layer tablet.
21. A detergent tablet as claimed in claim 20, wherein one layer of the basic tablet contains one or more bleaching agents while the other layer contains one or more enzymes.
22. A detergent tablet as claimed in claim 20 or 21, wherein one layer of the basic tablet contains one or more bleaching agents while the other layer contains one or more bleach activators.
23. A detergent tablet as claimed in any of claims 1 to 22, wherein the basic tablet contains protease and/or amylase.
24. A detergent tablet as claimed in any of claims 1 to 23, wherein the coating material of the region has a melting range of 45°C to 75°C.
25. A detergent tablet as claimed in any of claims 1 to 24, wherein the coating material of the region contains at least one substance from the group of polyethylene glycols (PEGs) with molecular weights in the range of 1500 to 36,000 and polypropylene glycols (PPGs).
26. A detergent tablet as claimed in claim 25, wherein the PEGs have a molecular weight in the range of 2000 to 6000.
27. A detergent tablet as claimed in claim 26, wherein the PEGs have a molecular weight in the range of 3000 to 5000.
28. A detergent tablet as claimed in any of claims 1 to 27, wherein the region contains one or more liquid amylase preparations and/or one or more liquid protease preparations.
29. A detergent tablet as claimed in any of claims 1 to 28, wherein the region contains other auxiliaries from the group of anti-settling agents, anti-sedimenting agents, anti-floating agents, thixotropicizing agents and dispersants in quantities of 0.5 to 8.0% by weight based on the region.

region contains other auxiliaries from the group of anti-settling agents, anti-sedimenting agents, anti-floating agents, thixotropicizing agents and dispersants in quantities of 0.5 to 8.0% by weight based on the region.
30. A detergent tablet as claimed in claim 29, wherein the other auxiliaries are present in quantities of 1.0 to 5.0%.
31. A detergent tablet as claimed in claim 30, wherein the other auxiliaries are present in quantities of 1.5 to 3.0%.
32. A detergent tablet as claimed in any of claims 1 to 31, wherein the region additionally contains emulsifiers from the group of fatty alcohols, fatty acids, polyglycerol esters and/or polyoxyalkylene siloxanes in quantities of 1 to 20% by weight based on the region.
33. A detergent tablet as claimed in claim 32, wherein the emulsifiers are present in quantities of 2 to 15% by weight.
34. A detergent tablet as claimed in claim 33, wherein the emulsifiers are present in quantities of 2.5 to 10% by weight.
35. A detergent tablet as claimed in any of claims 1 to 34, wherein, apart from the coating material(s) and the constituents of the liquid enzyme preparations, the region contains no other ingredients.
36. A process for the production of multiphase detergent tablets, comprising the following steps:
a) tabletting a particulate premix in known manner to form cavity tablets, b) preparing a melt dispersion from a coating material with a melting point above 30°C and one or more liquid enzyme preparation(s) dispersed therein, c) filling the tablets from step a) with the melt dispersion from step b) at temperatures above the melting point of the coating material, d) cooling and optionally aftertreating the filled detergent tablets.
37. A process for the production of multiphase detergent tablets, comprising the following steps a) preparing a melt dispersion from a coating material with a melting point above 30°C and one or more liquid enzyme preparation(s) dispersed therein, b) forming/shaping the melt dispersion in the solidification range of the melt to form a particulate composition, c) optionally mixing the particles formed in step b) with other particulate detergent ingredients and d) compressing the premixes formed in step b) or c) to form tablets or tablet regions.
38. A process as claimed in claim 36, wherein the premix tabletted in step a) contains builders in quantities of 20 to 80% by weight based on the premix.
39. A process as claimed in claim 38, wherein the premix contains builders in quantities of 25% to 75% by weight.
40. A process as claimed in claim 39, wherein the premix contains builders in quantities of 30 to 70% by weight.
41. A process as claimed in claim 36, 38, 39 or 40, wherein the particulate premix tabletted in step a) contains surfactant(s) in quantities of 0.5 to 10% by weight based on the premix.
42. A process as claimed in claim 41, wherein the premix contains surfactants in quantities of 0.75 to 7.5% by weight.
43. A process as claimed in claim 42, wherein the premix contains surfactants in quantities of 1.0 to 5% by weight.
44. A process as claimed in any of claims 41 to 43, wherein the surfactant(s) is a nonionic surfactant(s).
45. A process as claimed in any of claims 36 or 38 to 44, wherein the particulate premix tabletted in step a) has a bulk density above 600 g/l.
46. A process as claimed in claim 45, wherein the premix has a bulk density above 700 g/l.
47. A process as claimed in claim 46, wherein the premix has a bulk density above 800 g/l.

48. A process as claimed in any of claims 36 or 38 to 47, wherein the particulate premix tabletted in step a) has a particle size distribution in which less than 10% by weight of the particles are larger than 1600 µm or smaller than 200 µm.
49. A process as claimed in claim 48, wherein the premix has a particle size distribution in which less than 7.5% by weight of the particles are larger than 1600 µm or smaller than 200 µm.
50. A process as claimed in claim 49, wherein the premix has a particle size distribution in which less than 5% by weight of the particles are larger than 1600 µm or smaller than 200 µm.
51. A process as claimed in any of claim 36 or 38 to 50, wherein the premix has a particle size distribution in which more than 30% by weight of the particles are between 600 and 1000 µm in size.
52. A process as claimed in claim 51, wherein the premix has a particle size distribution in which more than 40% by weight of the particles are between 600 and 1000 µm in size.
53. A process as claimed in claim 52, wherein the premix has a particle size distribution in which more than 50% by weight of the particles are between 600 and 1000 µm in size.
54. A process as claimed in any of claims 36 or 38 to 53, wherein the multilayer recess tablets are produced in known manner in step a) by compressing several different particulate premixes onto one another.
55. A process as claimed in claim 54, wherein two-layer recess tablets are produced in step a) by pressing onto one another two different particulate premixes of which one contains one or more bleaching agents and the other one or more enzymes.
56. A process as claimed in claim 54 or 55, wherein two-layer recess tablets are produced in step a) by compressing onto one another two different particulate premixes of which one contains one or more bleaching agents and the other one or more bleach activators.
57. A process as claimed in any of claims 36 or 38 to 56, wherein the basic tablet produced in step a) contains protease and/or amylase.
58. A process as claimed in any of claims 36 or 38 to 57, wherein the melt dispersion prepared in step b) consists of 40 to 99.5% by weight of one or more coating material(s) with a melting point above 30°C, 0.5 to 60% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s) and 0 to 20% by weight optionally of other auxiliaries and/or active substances.
59. A process as claimed in claim 58, wherein the melt dispersion consists of 50 to 97.5% by weight of one or more coating material(s) with a melting point above 30°C.
60. A process as claimed in claim 59, wherein the melt dispersion consists of 60 to 95% by weight of one or more coating material(s) with a melting point above 30°C.
61. A process as claimed in claim 60, wherein the melt dispersion consists of 70 to 90% by weight of one or more coating material(s) with a melting point above 30°C.
62. A process as claimed in claim 58, wherein the melt dispersion consists of 1 to 40% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).
63. A process as claimed in claim 62, wherein the melt dispersion consists of 2.5 to 30% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).
64. A process as claimed in claim 63, wherein the melt dispersion consists of 5 to 25% by weight of one or more liquid enzyme preparation(s) dispersed in the coating material(s).
65. A process as claimed in claim 58, wherein the melt dispersion consists of 0 to 15% by weight optionally of other auxiliaries and/or active substances.

67. A process as claimed in claim 66, wherein the melt dispersion consists of 0 to 5% by weight optionally of other auxiliaries and/or active substances.
68. A process as claimed in claim 37, wherein the forming/ shaping step b) is carried out by granulation, compacting, pelleting, extrusion or tabletting.
69. A process as claimed in claim 37 or 68, wherein the particles formed in step b) are mixed with other particulate detergent ingredients to form a premix which is tabletted to form a single-layer tablet.
70. A process as claimed in claim 37, 68 or 69, wherein the particles formed in step b) are used without further additives as a premix for the production of a two-layer tablet by methods known per se.
71. A process as claimed in any of claims 36 to 70, wherein the coating material of the melt dispersion contains at least one substance from the group of polyethylene glycols (PEGs) with molecular weights in the range of 1500 to 36,000 and polypropylene glycols (PPGs).
72. A process as claimed in claim 71, wherein the PEGs have a molecular weight in the range of 2000 to 6000.
73. A process as claimed in claim 72, wherein the PEGs have a molecular weight in the range of 3000 to 5000.
74. A process as claimed in any of claims 36 to 73, wherein the melt dispersion contains one or more liquid amylase preparations and/or one or more liquid protease preparations.
75. The use of solidified melt dispersions of a) one or more coating material(s) with a melting point above 30°C, b) one or more liquid enzyme preparation(s) dispersed in the coating material(s) and c) optionally other auxiliaries and/or active substances in detergent tablets for dishwashing machines.
76. The use of enzymes dispersed in polyethylene glycols with c) optionally other auxiliaries and/or active substances in detergent tablets for dishwashing machines.
76. The use of enzymes dispersed in polyethylene glycols with molecular weights in the range from 1500 to 36,000 in detergent tablets for dishwashing machines.
77. The use as claimed in claim 76, wherein the polyethylene glycols have molecular weights in the range of 2000 to 6000.
78. The use as claimed in claim 77, wherein the polyethylene glycols have molecular weights in the range of 3000 to 5000.
79. The use of solidified melt dispersions of a) one or more coating material(s) with a melting point above 30°C, b) one or more liquid enzyme preparation(s) dispersed in the coating material(s) and c) optionally other auxiliaries and/or active substances for the rapid and long-lasting release of enzymes from detergent tablets containing these solidified dispersions.