MXPA01007832A - Coated detergent tablet. - Google Patents

Abstract

The present invention relates to a coated detergent tablet characterised in that the coating comprises a component which is liquid at 25 °C.

Description

TABLET DETERGENT COVERED FIELD OF THE INVENTION The present invention relates to coated detergent tablets, especially those that are adapted for use in washing machines, and to processes for preparing coated detergent tablets.

BACKGROUND OF THE INVENTION 10 Although detergent compositions have often been proposed in tablet form, these have not been substantially successful (with the exception of soap bars for personal washing), despite the various advantages of the products in the form of unit dispensation. 15 One of the reasons for this may be that detergent tablets require a relatively complex manufacturing process. In particular, it is often sought to provide the tablet with a coating, and • This adds manufacturing difficulties. Although the tablets without coating are completely 20 effective during their use, they usually lack the surface hardness necessary to resist abrasion that is part of normal manufacturing, packaging and handling operations. The result is that the uncoated tablets suffer from abrasion during these operations, obtaining desiccated tablets and loss of active material. Finally, it is often sought to coat the tablets for aesthetic reasons, to improve the outer appearance of the tablet or to • 5 achieve some particular aesthetic effect. Many methods of coating tablets have been proposed and many of them have been suggested for detergent tablets. However, all these methods have certain disadvantages, as will be explained below. 10 In GB-A-0 989 683, published on April 22, • 1965, describes a process for preparing a detergent in particles of surfactants and inorganic salts; water-soluble silicate is sprayed, and the detergent particles are compressed to form a tablet that retains a solid form. Finally, an organic polymer easily soluble in Water, film former, provides a coating to make the tablet detergent resistant to abrasion and accidental breakage. In EP-A-0 002 293, published on June 13, 1979, a tablet coating comprising a hydrated salt such as acetate, metaborate, orthophosphate, tartrate and sulfate is described. 20 In EP-A-0 716 144, published on June 12, 1996, laundry detergent tablets with water-soluble coatings are also described which can be organic polymers including acrylate / maleate copolymer, polyethylene glycol, PVPVA and sugar.

In WO9518215, published on July 6, 1995, water-insoluble coatings for solid-flushed tablets are provided. The tablets are provided with hydrophobic coatings including wax, fatty acid, fatty acid amides and polyethylene glycol. • 5 EP-A-0 846 754, published on June 10, 1998, provides a tablet having a coating comprising a dicarboxylic acid, the coating material having a melting point of 40 ° C to 200 ° on a regular basis. C. EP-A-0 846 755, published June 10, 1998, 10 provides a tablet having a coating comprising a material • insoluble in water at 25 ° C, such as C12-C22 fatty acids, adipic acid or C8-C13 dicarboxylic acids. EP-A-0 846 756, published on June 10, 1998, provides a tablet having a coating comprising a disintegrating material and preferably an effervescent material. The present invention provides a means by which tablets with such a coating can be provided that they can be stored, shipped and handled without damage, easily breaking such coating when the tablet is in the washing machine, releasing the 20 active ingredients in the washing solution. The object of the present invention is to provide a tablet having a coating that is sufficiently hard to protect the tablet from mechanical forces when stored, loaded and handled, and has sufficient flexibility to avoid cracking caused by mechanical stress.

BRIEF DESCRIPTION OF THE INVENTION • The object of the invention is achieved by providing a coated detergent tablet, characterized in that the coating comprises a component that is liquid at 25 ° C.

DETAILED DESCRIPTION OF THE INVENTION • Coating The strength of a tablet can be improved by making a tablet coated, covering the coating with an uncoated tablet, improving with 15 the mechanical characteristics of the tablet, and at the same time maintaining or improving its dissolution. This applies very advantageously to layer tablets • multiple, by means of which the mechanical characteristics of a more elastic layer can be transmitted by means of the coating to the rest of the tablet, 20 thus combining the advantage of the coating with the advantage of the more elastic layer. In fact, the mechanical constraints will be transmitted through the coating, thus improving the mechanical integrity of the tablet. In one embodiment of the present invention, the tablets can then be coated so that the tablet does not absorb moisture, or absorb moisture only at a very low rate. The coating is also resistant so that the mechanical shocks to which the tablet is subjected during handling, packaging and shipping, do not produce more than very low levels of • 5 breakage or wear. Finally, the coating is preferably brittle, so that the tablet will fragment rapidly upon subjecting it to a stronger mechanical shock. In addition, it is convenient that the coating material dissolves under alkaline conditions, that is, easily emulsified with surfactants. This helps to avoid the problem of visible residue in the window of a front loading washing machine • during the wash cycle, and also avoids the deposition of undissolved particles or lumps of coating material on the wash load. The solubility in water is measured following the protocol of ASTM E1148-87 entitled "Standard Test Method for Measurements of Aqueous 15 Solubility". The coating material has a preferable melting point of 40 ° C to 200 ° C. • The coating can be applied in several ways. Two preferred methods of coating are (a) coating with a molten material, and (b) coating with a solution of the material. In method (a), the coating material is applied at a temperature above its melting point, and solidifies in the tablet. In method (b), the coating is applied as a solution, from which the solvent is dried to leave a coherent coating. The substantially insoluble material can be applied to the tablet, for example, by spraying or dipping. Normally when the molten material is sprayed onto the tablet, it solidifies rapidly to form a coherent coating. When the tablets are immersed in the molten material and then removed, the rapid cooling again causes rapid solidification of the coating material. During the solidification phase, the coating undergoes some internal stress (for example shrinkage due to cooling) and external stresses (for example loosening of the tablet). This will likely cause some cracks in the structure such as edge cracking, if the coating material is too brittle to resist these mechanical stresses, which is the case when a coating is made only of solid components at 25 ° C. In fact, according to the invention, the coating comprises a component that is liquid at 25 ° C. It is believed that this liquid component will allow the coating to better resist and absorb mechanical stresses by making the structure of the coating more flexible. The component which is liquid at 25 ° C, is preferably added to the coating materials in proportions of less than 10% by weight of the coating, preferably less than 5% by weight, and less than 3% by weight is very preferred. The component which is liquid at 25 ° C, is preferably added to the coating materials in proportions of more than 0.1% by weight of the coating, preferably more than 0.3% by weight, and more than 0.5% by weight is very preferred. In addition, it is preferred to add reinforcing fibers to the coating to further strengthen its structure. Preferably, the coating comprises a crystallized structure. By crystallized it must be understood that the coating • 5 comprises a material that is solid at room temperature (25 ° C) and has a structure that exhibits a certain order. This can be detected regularly by means of normal crystallography techniques, for example X-ray analysis on the same material. In a highly preferred embodiment, the material forming the crystallized structure does not co-crystallize, or co-crystallize 10 only partially, with the optional component that is liquid at 25 ° C mentioned above. In fact, it is preferred that the optional component remain in the liquid state at 25 ° C in the crystalline coating structure to provide structure flexibility and resistance to mechanical stress. In another embodiment, the component that is liquid at 25 ° C can 15 conveniently having laundry functionality, for example silicone oil, which provides benefits of foam suppression or perfume oil. • - The coating comprises other materials than the component that is liquid at 25 ° C. Suitable coating materials 20 are, for example, dicarboxylic acids. Particularly suitable dicarboxylic acids are selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid and mixtures of the same. Adipic acid is very preferred. It is clear that substantially insoluble materials having a melting point below 40 ° C are not sufficiently solid at room temperature, and it has been found that it is not practical to use materials having a melting point above about 200 ° C. . Preferably, the materials are melted at a temperature in the range of 60 ° C to 160 ° C. It was found that an acid having a melting point of more than 145 ° C, such as adipic acid, is particularly suitable. By "melting point" is meant the temperature at which the material becomes a clear liquid when heated slowly, for example in a capillary tube. In accordance with the present invention, a coating of any desired thickness can be applied. For the majority of cases, the coating forms from 1% to 10%, preferably from 1.5% to 5% of the weight of the tablet. The coatings on the tablet are very hard and provide extra resistance to the tablet. Examples of optional components that are liquid at 25 ° C include polyethylene glycols, thermal oil, silicone oil, esters of dicarboxylic acids, monocarboxylic acids, paraffin, triacetin, perfumes or alkaline solutions. It is preferred that the structure of the components which are liquid at 25 ° C be almost equal to that of the material forming the crystallized structure, so that the structure is not excessively interrupted. In a highly preferred embodiment, the crystallized structure is made of adipic acid, the component being available which is liquid at 25 ° C under the name Coasol ™ from Chemoxy International, being a mixture of the diisobutyl esters of glutaric, succinic and adipic acid. The advantage of using this component is the good dispersion of adipic acid to provide flexibility. It should be noted that the disintegration of the adipic acid further improves with the adipate content of Coasol ™. The fracture of the coating in the wash can be improved by adding a disintegrant in the coating. This disintegrant will swell once in contact with water and break the coating into small parts. This will improve the dissolution of the coating in the wash solution. The disintegrant is suspended in the melted coating at a level of up to 30%, preferably between 5% and 20%, preferably between 5% and 10% by weight. Possible disintegrants are described in "Handbook of Pharmaceutical Excipients" (1986). Examples of suitable disintegrants include starch: natural, modified or pregelatinized, sodium gluconate starch; gum: agar gum, guar gum, locust bean gum, karaya gum, pectin gum, tragacanth gum; sodium croscarmilose, crospovidone, cellulose, carboxymethylcellulose, alginic acid and its salts, including sodium alginate, silicon dioxide, clay, polyvinylpyrrolidone, soy polysaccharides, ion exchange resins, polymers containing cationic groups (for example quaternary ammonium), amino-substituted polyacrylates, polymerized cationic amino acids such as poly-L-lysine, polyallylamine hydrochloride) and mixtures thereof. In a highly preferred embodiment, the coating according to the invention comprises adipic acid, as well as a clay, wherein the clay is used as a disintegrant and also to make the adipic acid structure more favorable for water penetration, thus improving the dispersion of the adipic acid in an aqueous medium. To obtain the desired effect on the adipic acid structure, clays having a particle size of less than 75 m, preferably less than 53 m are preferred. Bentonite clays are preferred. In fact, the adipic acid has a melting point at which the traditional cellulose disintegrants undergo thermal degradation during the coating operation, while such clays are more stable to heat. In addition, it is known that for example a traditional cellulosic disintegrant such as Nymcel ™ turns brown at these temperatures. In another preferred embodiment, the coating also comprises reinforcing fibers. It has been found that these fibers further improve the resistance of the coating to mechanical stress and reduce the occurrence of cracking defects. These fibers preferably have a length of at least 100 m, preferably at least 200 m, and preferably at least 250 m to allow reinforcement of the structure. These fibers preferably have a length of less than 500 m, preferably less than 400 m, and preferably less than 350 m, so as not to have an impact on the dispersion of the coating in an aqueous medium. Materials that can be used for these fibers include viscose rayon, natural nylon, synthetic nylon (polyamides type 6 and 6,6), acrylic, polyester, cotton and cellulose derivatives such as CMCs. A cellulosic material available under the trademark Solka-Floc ™ from Fibers Sales & Development. It should be noted that such fibers do not normally require precompression to reinforce the structure of the coating. These fibers are preferably added at a level of less than 5% by weight of the coating, preferably less than 3% by weight. These fibers are preferably added at a level of more than 0.5% by weight of the coating, preferably more than 1% by weight. A preferred process for preparing a tablet according to the invention comprises the steps of: (a) forming a core by compressing a particulate material, said particulate material comprising surfactant and builder; (b) applying a coating material to the core, this coating material being in a molten form; (c) allowing the molten coating material to solidify; the coating is characterized in that it comprises a component that is liquid at 25 ° C. Another method for preparing a tablet according to the invention comprises the steps of: (a) forming a core by compressing a particulate material, said particulate material comprising surfactant and builder; (b) applying a coating material to the core, this coating material being dissolved in a solvent or water; (c) allow the solvent or water to evaporate; the coating is characterized in that it comprises a component that is liquid at 25 ° C. A very preferred process is like those mentioned above, wherein the coating material, or the mixture of materials, has a melting point of at least 145 ° C., the coating comprising a clay. In fact, the typical cellulose disintegrants would begin to degrade at that temperature. This applies particularly when adipic acid is used. The tablets may comprise components such as fragrance, surfactants, enzymes, detergents, etc. Typical tablet compositions are described for the preferred embodiment of the present invention, for example, in pending European applications Nos. 96203471. 6, 96203462.5, 96203473.2 and 96203464.1. In the following paragraphs the elements that typically enter into the composition of detergent tablets or other forms of detergents such as liquids or granules are described in detail.

Highly soluble compounds The tablet can comprise a highly soluble compound. Said compound can be formed of a mixture of compounds or of a single compound. A highly soluble compound is defined as follows: A solution comprising deionized water and 20 grams per liter of a specific compound is prepared in the following manner: 1 - 20 g of the specific compound are placed in a Sotax flask. This flask is placed in a bath at a constant temperature set at 10 ° C. A stirrer with a marine propeller is placed in the flask in such a way that the bottom of the agitator is 5 mm above the bottom of the Sotax flask. The mixer is set at a rotation speed of 200 revolutions per minute. 2- 980 g of the deionized water are introduced into the Sotax flask. 3- After 10 seconds of the introduction of water, the conductivity of the solution is measured using a conductivity meter. 4- Repeat step 3 after 20, 30, 40, 50 sec, 1 min, 2 min, 5 min and 10 min after step 2. 5- The measurement taken at 10 min is used as the plateau value or mum value. According to the invention, the specific compound is highly soluble when the conductivity of the solution reaches 80% of its mum value in less than 10 seconds, starting from the complete addition of the deionized water to the compound. In fact, when conductivity is monitored in this way, the conductivity reaches a plateau after a certain period, this plateau being considered as the mum value. Said compound is preferably in the form of a fluid material consisting of solid particles at temperatures between 10 and 80 degrees Celsius for ease of handling; however other forms such as a paste or a liquid may be used. Examples of highly soluble compounds include sodium diisoalkylbenzene sulfonate (DIBS) or sodium toluene sulfonate.

Cohesive effect The tablet may comprise a compound having a cohesive effect on the particulate material of a detergent matrix forming the tablet. The cohesive effect on the particulate material of a detergent matrix forming the tablet or a layer of the tablet is characterized by the force required to break the tablet or layer based on the examined detergent matrix pressed under controlled compression conditions. For a given compression force, a high resistance of the tablet or layer indicates that the granules were strongly bonded when compressed, so that a strong cohesive effect took place. Means for determining the strength of the tablet or layer (also referred to as diametral fracture stress) are given in "Pharmaceutical Dosage Forms: Tablets," volume 1, Ed. H.A. Lieberman and others, published in 1989. The cohesive effect is measured by comparing the strength of the tablet or layer of the original base powder without compound with cohesive effect, with the strength of the tablet or layer of a powder mixture comprising 97 parts of the powder original base and 3 parts of the compound that has a cohesive effect. The compound having a cohesive effect is preferably added to the matrix in substantially water-free form (water content below 10% (preferably below 5%)). The temperature of the addition is between 10 and 80 ° C, preferably between 10 and 40 ° C. A compound is said to have a cohesive effect on the particulate material according to the invention, when at a given compression force of 3000N, tablets with a weight of 50 g of detergent particulate material, and a diameter of 55 mm, are increased its tensile strength in more than 30% (preferably 60%, preferably 100%) with the presence of 3% of the compound having the cohesive effect in the base particulate material. An example of a compound having a cohesive effect is sodium diisoalkylbenzenesulfonate. When integrating a highly soluble compound that also has a cohesive effect on the particulate material used for a tablet or layer formed by compressing a particulate material comprising a surfactant, significantly increases the dissolution of the tablet or layer in an aqueous solution. In a preferred embodiment, at least 1% by weight of a tablet or layer is formed of the highly complex compound 1. soluble, preferably at least 2%, preferably at least 3%, and at least 5% by weight of the tablet or layer formed of the highly soluble compound having a cohesive effect on the particulate material is very preferred. It should be noted that a composition comprising a highly soluble compound, as well as a surfactant, is described in EP-A-0 524 075, this composition being a liquid composition. A highly soluble compound having a cohesive effect on the particulate material allows to obtain a tablet having a higher tensile strength at a constant compression force, or equal tensile strength at a lower compression force, when compared with traditional tablets. Typically, a complete tablet will have a tensile strength of more than 5 kPa, preferably of more than 10 kPa, preferably, in particular for use in laundry applications, of more than 15 kPa, preferably of more than 30 kPa, and preferably of more than 50 kPa, in particular for use in dishwashing or automatic dishwashing applications; and a tensile strength of less than 300 kPa, preferably less than 200 kPa, preferably less than 100 kPa, preferably less than 80 kPa, and most preferably less than 60 kPa. In fact, in the case of laundry application, the tablets should be less compressed than for example in the case of automatic dishwashing applications, whereby the dissolution is more easily reached; such that in a laundry application, the tensile strength is preferably less than 30 kPa. This makes it possible to produce tablets or layers having a strength and mechanical strength comparable to the strength or mechanical strength of traditional tablets, while having a less compact tablet or layer which thus dissolves more easily. In addition, since the compound is very soluble, the dissolution of the tablet or layer is further facilitated, resulting in a synergy leading to the facilitated dissolution of a tablet according to the invention.

Manufacture of the tablet The tablet may comprise several layers. For single layer manufacturing purposes, the layer can be considered as a tablet by itself. Detergent tablets can be prepared by simply mixing the solid ingredients and compressing the mixture in a conventional tablet press such as those used for example in the pharmaceutical industry. Preferably, the main ingredients, in particular the gelling surfactants, are used in particulate form. Any liquid ingredient, for example, surfactant or foam suppressant, can be incorporated in the conventional manner into the solid particulate ingredients.

In particular, for laundry tablets, the ingredients such as builder and surfactant can be spray-dried in the conventional manner and then compressed to a suitable pressure. Preferably, the tablets according to the invention are compressed using a force of less than 100000 N, preferably less than 50000 N, preferably less than 5000 N and most preferred of less than 3000 N. In fact, the preferred embodiment is a tablet suitable for laundry, compressed using a force of less than 2500 N, but can also be considered for example automatic dishwashing tablets, which are usually more compressed than laundry tablets. The particulate material used to prepare a tablet can be made by any method of particle formation or granulation. An example of such a process is spray drying (in a concurrent current or counter current spray drying tower), which regularly gives low apparent densities of 600 g / l or lower. Higher density particulate materials can be prepared by granulation and densification in a high shear load mixer / granulator, or by means of a continuous granulation and densification process (for example using the Lodige® CB and / or Lodige® KM mixers). Other suitable methods include fluid bed processes, compression methods (e.g. roll compression), extrusion, and also any particulate material made by any chemical process such as flocculation, crystallization, sintering, etc. The individual particles can also be any other particle, granule, sphere or grain. The components of the particulate material can be mixed by any conventional means. It is suitable in batches for example in a concrete mixer, Nauta mixer, ribbon mixer or any other. Alternatively, the mixing operation can be carried out continuously by dosing each component by weight on a moving band, and mixing them in one or more drums or mixers. The non-gelling binder can be sprayed onto the mixture of some or all of the components of the particulate material. Other liquid ingredients can also be sprayed on the mixture of components, either separately or premixed. For example, perfume and suspensions of optical brighteners can be sprayed. After spraying the binder, preferably at the end of the operation, a finely divided flow aid (dyeing agent such as zeolites, carbonates, silicas) can be added to the particulate material to make the mixture less sticky. The tablets can be manufactured using any compression operation such as tabletting, agglomeration or extrusion, preferably tableting. The right equipment includes a standard monopsonic or rotary press (such as CourtoyR, KorchR, ManestyR or BonalsR). The tablets prepared according to this invention preferably have a diameter between 20 mm and 60 mm, preferably at least 35 mm and up to 55 mm, and a weight between 25 and 100 g. The ratio of height to diameter (or width) of the tablets is preferably greater than 1: 3, preferably greater than 1: 2. It is required that the compression pressure used to prepare these tablets is not greater than 100000 kN / m2, preferably not greater than 30000 kN / m2, preferably not greater than 5000 kN / m2, preferably not more than 3000 kN / m2 , and it is very preferred no greater than 1000 kN / m2. In a preferred embodiment according to the invention, the tablet has a density of at least 0.9 g / cc, preferably of at least 1.0 g / cc, and preferably less than 2.0 g / cc, preferably less than 1.5 g / cc, preferably less than 1.25 g / cc, and less than 1.1 g / cc is very preferred. Multilayer tablets are formed regularly in rotary presses by placing the matrices of each layer, one after the other, in forced flow matrix feeders. As the operation proceeds, the layers of the matrix are pressed together in the precompression and compression stations to form the multi-layer tablet. With some rotary presses, it is also possible to compress the first fed layer before compressing the entire tablet.

Hydropoid Compound A highly soluble compound that has a cohesive effect can be integrated into a detergent tablet, whereby this compound is also a hydrotrope compound. Said hydrotrope compound can generally be used to promote the dissolution of surfactant avoiding gelation. A specific compound is defined as a hydrotrope in the following manner (see SE Friberg and M. Chiu, J. Dispersion Science and Technology, 9 (5 &6), pages 443 to 457 (1988-1989)): 1. Prepare a solution comprising 25% by weight of the specific compound and 75% by weight of water. 2. Then octanoic acid is added to the solution in a proportion of 1.6 times the weight of the specific compound in solution, the solution being at a temperature of 20 ° Celsius. The solution is mixed in a Sotax flask with an agitator with marine propeller, this propeller being located approximately 5 mm above the bottom of the flask, and placing the mixer at a rotation speed of 200 revolutions per minute. 3. The specific compound is hydrotrope if the octanoic acid is completely dissolved, that is, if the solution comprises only one phase, this phase being a liquid phase. It should be noted that in a preferred embodiment of the invention, the hydrotrope compound is a fluid material of solid particles at operating conditions of between 15 and 60 ° Celsius. The hydrotrope compounds include the compounds referred to below: A list of commercial hydrotropes could be found in "McCutcheon's Emulsifiers and Detergents", published by McCutcheon Division of Manufacturing Confectioners Company. Compounds of interest also include: 1. Nonionic hydrotropes with the following structure: R-O- (CH2CH2O) x (CH-CH2?) And H CH3 where R is a C8-C10 alkyl chain, x varies from 1 to 15, and "y" from 3 to 10. 2. Anionic hydrotropes such as alkali metal arylsulfonates. This includes alkali metal salts of benzoic acid, salicylic acid, benzenesulfonic acid and its many derivatives, naphthoic acid and various hydro-aromatic acids. Examples of these are the sodium, potassium and ammonium benzenesulfonate salts derived from toluenesulfonic acid, xylenesulfonic acid, cumene sulphonic acid, tetralinsulphonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, dimethylnaphthalenesulfonic acid, trimethylnaphthalene sulfonic acid. Other examples include dialkylbenzenesulfonic acid salts such as the salts of diisopropylbenzenesulfonic acid, ethylmethylbenzenesulfonic acid, alkylbenzenesulfonic acid with an alkyl chain length of 3 to 10 (preferably 4 to 9), linear or branched alkyl sulfonates with an alkyl chain of 1 to 18 carbons. 3. Solvent hydrotropes such as alkoxylated glycerines and alkoxylated glycerides, esters of alkoxylated glycerines, alkoxylated fatty acids, glycerin esters, polyglycerol esters. The preferred alkoxylated glycerines have the following structure: wherein I, m and n are each a number of 0 about 20, with l + m + n = 2 to about 60, preferably about 10 to about 45, and R represents H, CH3 or C2H5. Preferred alkoxylated glycerides have the following structure: wherein Ri and R2 are each CnCOO or - (CH2CHR3-O) rH, wherein R3 = H, CH3 or C2H5 and I is a number from 1 to about 60, n is a number from about 6 to about 24. 4 Polymeric hydrotropes such as those described in EP636687: wherein E is a hydrophilic functional group, R is H or a C1-C10 alkyl group or is a hydrophilic functional group; Ri is H or a lower alkyl group or an aromatic group, R 2 is H or a cyclic alkyl or an aromatic group. The polymer regularly has a molecular weight of between 1000 and 1000000, approximately. 5. Hydrotrope of unusual structure such as 5-carboxy-4-hexyl-2-cyclohexen-1-yl-octanoic acid (Diacid®). The use of said compound in the invention would further increase the rate of dissolution of the tablet, since for example a hydrotrope compound facilitates the dissolution of the surfactants. Said compound could be formed of a mixture of compounds or of a single compound.

Resistance to tension In order to measure the resistance to tension of a layer, it can be considered as a tablet by itself. Depending on the composition of the starting material and the shape of the tablets, the compression force used can be adjusted so as not to affect the tensile strength or disintegration time in the washing machine. This method can be used to prepare homogeneous tablets or tablets of layers, of any size or shape.

For a cylindrical tablet, the tensile strength corresponds to the diametral fracture stress (DFS), which is a way to express the strength of a tablet or layer, and is determined by the following equation: Resistance to tension = 2 F / pDt where F is the maximum force (Newtons) to cause a failure (fracture) to the tension, measured by means of a VK 200 tablet hardness tester provided by Van Kell Industries Inc. D is the diameter of the tablet or layer, and t is the thickness of the tablet or layer. For a non-round tablet, simply pD is replaced by the perimeter of the tablet ("Method Pharmaceutical Dosage Forms: Tablets", volume 2, pages 213 to 217). A tablet that has a diametral fracture stress of less than 20 kPa is considered fragile, and will likely cause some fractured tablets to be delivered to the consumer. A diametral fracture stress of at least 25 kPa is preferred. This applies similarly to non-cylindrical tablets to define the tensile strength, where the normal cross-section at the height of the tablet is not round, and where the force is applied along a direction perpendicular to the direction of the height of the tablet and normal next to the tablet, this side being perpendicular to the non-round cross section.

Dispensing the Tablet The dispensing speed of a detergent tablet can be determined as follows: Two tablets nominally weighing 50 grams are weighed and then placed in the dispenser of a Baucknecht® WA9850 washing machine. The water supply of the washing machine is set at a temperature of 20 ° C and a hardness of 21 grains by 3.78 liters, setting a water inlet flow rate to the dispenser of 8 l / min. The level of remaining tablet residues in the dispenser is checked by turning on the wash and the wash cycle is set in program 4 (white / colored, short cycle). The percentage of dispensation is determined as follows:% dispensing = weight of residue x 100 / original weight of the tablet The level of residues is determined by repeating the procedure 10 times and an average residue level is calculated based on 10 measurements individual In this stress test, a residue of 40% of the initial weight of the tablet is considered acceptable. A residue of less than 30%, and it is very preferred of less than 25%. It should be noted that the measurement of water hardness is given in the traditional unit of "grains per gallon [3.78 liters]", with which 0.001 moles per liter = 7.0 grains per 3.78 liters, which represents the concentration of Ca2 + ions in solution.

Effervescent agent The detergent tablets may also comprise an effervescent agent. As defined herein, effervescence means the evolution of gas bubbles from a liquid, as a result of a chemical reaction between a source of soluble acid and an alkali metal carbonate, to produce gaseous carbon dioxide, that is, C6H8O7 + 3NaHCO3? Na3C6H5O7 + 3CO2 t + 3H2O Additional examples of acid and carbonate sources, and other effervescent systems, can be found in "Pharmaceutícal Dosage Forms: Tablets", volume 1, pages 287 to 291. An effervescent agent can be added to the mixture for tablets, in addition to the detergent ingredients. The addition of this effervescent agent to the detergent tablet improves the disintegration time of the tablet. The amount will preferably be between 5 and 20%, preferably between 10 and 20% by weight of the tablet. Preferably, the effervescent agent must be added as an agglomerate of the different particles or as compact particles, and not as separate particles. Due to the gas created by the effervescence in the tablet, it may have a higher DFS and still have the same disintegration time as the tablet without effervescence. When the DFS of the tablet is maintained with effervescence equal to that of the tablet without effervescence, the disintegration of the tablet with effervescence will be faster.

An additional dissolution aid can be provided using compounds such as sodium acetate or urea. In "Pharmaceutical Dosage Forms: Tablets" volume 1, second edition, edited by H.A. Líberman et al., ISBN 0-8247-8044-2. Detersive Surfactants Surfactants are regularly contained in a detergent composition. The dissolution of surfactants is favored by the addition of the highly soluble compound. Non-limiting examples of surfactants useful herein, typically at levels of 1% to 55% by weight, include the alkylbenzene sulfonates ("LAS") of C < | - C 1 -C 8 conventional and branched chain randomized C 10-2 O 'alkyl sulfates ("AS"), the secondary alkyl sulfates (2,3) of C < | rj- i8 of the formula CH3 (CH2) x (CHOSO3-M +) CH3 and CH3 (CH2) and (CHOSO3-M +) CH2CH3, where x and (y +1) are integers of at least about 7, preferably at least 9, and M is a cation of solubilization in water, especially sodium; unsaturated sulfates such as oleyl sulfate, ClO-Ci8 alkylalkoxy sulfates ("AEXS", especially ethoxysulfates of 1-7 EO); C10-C18 alkylalkoxycarboxylates (especially the ethoxycarboxylates of 1-5 EO), the glycerol ethers of C10-C18. C10-C8 alkyl polyglycosides and their corresponding sulfated polyglycosides, and alphasulfonated fatty acid esters of C- | 2_Ci8- If desired, conventional non-ionic and amphoteric surfactants such as alkyl ethoxylates ("AE") can also be included in the final compositions. ") of C-12-C 8 including the so-called narrow-spiked alkyl ethoxylates and the Cg-C ^ alkylfenoxycolates (especially ethoxylates and ethoxy / mixed propoxy), betaines and sulfobetaines (" sultaines ") of C-12-C18. amine oxides of C- | rj-Ci8. and similar. The C-io-C-is N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include C- | 2-Ci8 N-methylglucamides. See WO 9,206,154. Other surfactants derived from sugar include the N-alkoxypolyhydroxy fatty acid amides, such as N- (3-methoxypropyl) glucamide from C < | rj-Ci8- N-propyl to C-i2-Ci8 N-hexylglucamides can be used for low foaming- Conventional C? rj-C20 soaps can also be used- If high foaming is desired, they can be used IC-CI branched-chain soaps 6- mixtures of anionic and non-ionic surfactants are especially useful. Other useful conventional surfactants are mentioned in the standard texts. In a preferred embodiment, the tablet comprises at least 5% by weight of surfactant, preferably at least 15% by weight, preferably at least 25% by weight, and most preferably between 35% and 45% by weight of surfactant agent.

Non-gelling binders To facilitate further dissolution, non-gelling binders can be integrated into the detergent compositions. If non-gelling binders are used, suitable ones include synthetic organic polymers such as polyethylene glycols, polyvinyl pyrrolidones, polyacrylates and water-soluble acrylate copolymers. The "Handbook of Pharmaceutical Excipients" manual, second edition, has the Binding properties inside the tablet. The non-gelling binder materials are preferably used in an amount on the scale of 0.1 to 15% of the composition, preferably less than 5% and, especially if it is not an active laundry material, less than 2% by weight of the tablet . It is preferred to avoid gelling binders, such as nonionic surfactants, in their liquid or molten form. The nonionic surfactants and other gelling binders are not excluded from the compositions, but it is preferred that they be processed in the detergent tablets as components of particulate materials, and not as liquids.

Detergency builders To assist in controlling mineral hardness, builders may optionally be included in the present compositions.

Both inorganic and organic builders can be used. Detergency builders are often used in fabric washing compositions to help remove particulate soils. The level of improver can vary widely depending on the final use of the composition. Inorganic or P-containing builders They include, without limitation, the alkali metal, ammonium and alkanolammonium salts of polyphosphates (polished by the glassy polymeric tripolyphosphates, pyrophosphates and metaphosphates), phosphonates, phytic acid, silicates, carbonates (including bicarbonates and sesquat carbonates), sulphates and aluminosilicates. However, in certain locations builders are required that are not phosphate builders. Importantly, the compositions herein work surprisingly well even in the presence of so-called "weak" detergency builders (as compared to phosphate builders) such as citrates, or in the so-called "lower detergency enhancement" situation that It can occur with zeolite builders or stratified silicate. Examples of silicate builders are alkali metal silicates, particularly those having a Si 2: Na 2 ratio. in the scale from 1.6: 1 to 3.2: 1 and layered silicates, such as the layered sodium silicates described in the U.S. Patent. 4,664,839, issued May 12, 1987 for H.P. Rieck NaSKS-6 is the trademark of a crystalline layered silicate sold by Hoechst (commonly abbreviated here as "SKS-6"). Unlike the zeolite detergent builders, the NaSKS-6 silicate builder does not contain aluminum. The NaSKS-6 has the morphological form delta-Na2Si? 5 of stratified silicate. It can be prepared by methods such as those described in the publications of DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly preferred stratified silicate for use herein, but other layered silicates, such as those having the general formula NaMSix? 2? +? yH2? wherein M is sodium or hydrogen, x is a number from 1.9 to 4, preferably 2, and "y" is a number from 0 to 20, preferably 0. Some other stratified silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11 as the alpha, beta and gamma forms. As indicated above, the delta-Na2Si? 5 (NaSKS-6) form is most preferred for use herein. Other silicates such as for example magnesium silicate, which can serve as a tightening agent in granulated formulations, as a stabilizing agent for oxygen bleaches, and as a component of foam control systems may be useful. Examples of carbonate builders are alkaline earth metal and alkaline metal carbonates which are described in German Patent Application No. 2,321,001, published November 15, 1973. Aluminosilicate builders are useful in the present invention . Aluminosilicate builders are of great importance in most heavy duty granular detergent compositions currently marketed, and can also be an important improving ingredient in liquid detergent formulations. Aluminosilicate detergency builders include those with the empirical formula: Mz [(zAIO2) and] xH2O where z and "y" are integers of at least 6, the molar ratio of zay is in the range of about 1.0 to 0.5, and x is an integer of about 15 to about 264. Useful ion exchange materials are commercially available. of aluminosilicate. These aluminosilicates can be of crystalline or amorphous structure and can be aluminosilicates of natural origin or synthetically derived. A method for producing aluminosilicate ion exchange materials is described in the U.S. Patent. 3,985,669, Krummel et al., Issued October 12, 1976. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein, are available under the designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula: Na12 [(Al? 2)? 2 (Si? 2) l2] xH20 wherein x is from about 20 to about 30, especially about 27. This material is known as Zeolith A. Dehydrated zeolites (x = 0-10) can also be used here. Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in diameter. Organic builders suitable for the purposes of the present invention include, without restriction, a wide variety of polycarboxylate compounds. As used herein, "polycarboxylate" refers to compounds having a plurality of carboxylate groups, preferably at least 3 carboxylates. The polycarboxylate builder can usually be added to the composition in acid form, but can also be added in the form of a neutralized salt. When used in salt form, alkali metal salts such as sodium, potassium and lithium, or alkanolammonium are preferred. Included among the polycarboxylate builders are a variety of useful material categories. An important category of polycarboxylate builders encompasses ether polycarboxylates that include oxydisuccinate, as described by Berg in the U.S.A. 3,128,287, issued April 7, 1964, and Lamberti et al., Patent of E.U.A. No. 3,635,830, issued January 18, 1972. See also the "TMS / TDS" detergency builders of the U.S. patent. No. 4,663,071, issued to Bush et al. On May 5, 1987. Suitable ether polycarboxylates also include cyclic compounds, particularly alicyclic compounds such as those described in U.S. Pat. Nos. 3,923,679, 3,835,163; 4,158,635; 4,120,874, and 4,102,903. Other useful detergency builders include ether hydroxypolycarboxylates, maleic anhydride copolymers with ethylene or vinyl methyl ether, 1,3-trihydroxybenzene-2,4,6-trisulfonic acid, and carboxymethyloxysuccinic acid, the different alkali metal salts, ammonium and substituted ammonium of polyacetic acids such as ethylenediaminetetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene-3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and the soluble salts of the same. Citrate builders, for example, citric acid and soluble salts thereof (particularly sodium salt), are polycarboxylate builders of particular importance for heavy duty liquid detergent formulations, due to their availability from resources renewable and its biodegradability. The citrates can also be used in granular compositions, especially in combination with zeolite builders and / or layered silicate. Oxydisuccinates are also especially useful in said compositions and combinations. Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-1,6-hexanediates and the related compounds described in the U.S. Patent. No. 4,566,984, issued to Bush on January 28, 1986. Useful succinic acid builders include the C5-C20 alkyl and alkenyl succinic acids and salts thereof. A particularly preferred compound of this type is dodecenylsuccinic acid. Specific examples of succinate builders include: laurylsuccinate, myristylsuccinate, palmitiisuccinate, 2-dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, and the like. Lauryl succinates are the preferred builders of this group, and are described in European Patent Application 86200690.5 / 0,200,263, published on November 5, 1986.

Other suitable polycarboxylates are described in U.S. Pat. No. 4,144,226, Crutchfield et al., Issued March 13, 1979, and in the US patent. No. 3,308,067, Diehl, issued March 7, 1967. See also Diehl, patent of E.U.A. No. 3,723,322. To provide additional detergency builder activity, fatty acids, for example, C-12-C18 monocarboxylic acids, may also be incorporated into the compositions. alone or in combination with the aforementioned detergency builders, especially the citrate and / or succinate builders. Such use of fatty acids will generally result in decreased foaming, which should be considered by the formulator. In situations where phosphorus-based detergency builders can be used, and especially in the bar formulations used for hand washing operations, various alkali metal phosphates can be used such as the well-known sodium tripolyphosphates, sodium pyrophosphate. and sodium orthophosphate. Phosphonate builders such as ethan-1-hydroxy-1,1-diphosphonate and other known phosphonates can also be used (see, for example, U.S. Patent Nos. 3,159,581; 3,213,030; 3,422,021; 3,400,148 and 3,422,137).

Blanket The detergent compositions herein may optionally contain bleaching agents or bleaching compositions containing a bleaching agent and one or more bleach activators. When present, the bleaching agents will be at levels of from about 1% to about 30%, typically from about 5% to about 20% of the detergent composition, especially for fabric washing. If present, the amount of bleach activators will typically be from about 0.1% to about 60%, more typically from about 0.5% to about 40% of the bleaching composition comprising the bleaching agent plus bleach activator. The bleaching agents used herein may be any of the bleaching agents useful for detergent compositions in cleaning textiles, cleaning hard surfaces or other cleaning purposes now known or to be known. These include oxygen bleaches as well as other bleaching agents. Perborate whiteners, for example, sodium perborate (e.g. mono or tetrahydrate) can be used in the present. Another category of bleaching agent that can be used without restriction comprises percarboxylic acid bleaching agents and salts thereof. Suitable examples of this class of agents include magnesium monoperoxyphthalate hexahydrate, the magnesium salt of metachloroperbenzoic acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydecanedioic acid. Said bleaching agents are described in the patent of E.U.A. 4,483,781, Hartman, issued November 20, 1984; Patent Application of E.U.A. 740,446, Burns et al., Filed on June 3, 1985, European Patent Application 0,133,354, Banks et al., Published on February 20, 1985, and the patent of E.U.A. 4,412,934, Chung et al., Issued November 1, 1983. Highly preferred bleaching agents also include 6-nonylamino-6-oxoperoxycaproic acid as described in the U.S. Patent. 4,634,551, issued January 6, 1987 to Burns et al. Peroxygen bleaching agents can also be used. Suitable peroxygen bleach compounds include sodium carbonate peroxyhydrate and equivalent "percarbonate" bleaches, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Persulfate bleach can also be used (e.g., OXONE, commercially manufactured by DuPont). A preferred percarbonate bleach comprises dry particles having an average particle size in the range of about 500 microns to about 1,000 microns, with no more than about 10% by weight of said particles being smaller than about 200 microns, and no more than about 10% by weight of said particles being larger than about 1.250 microns. Optionally, the percarbonate can be coated with silicate, borate or water-soluble surfactants. Percarbonate is available from various commercial sources such as FMC, Solvay and Tokai Denka. Mixtures of bleaching agents can also be used. Peroxygen bleaching agents, perborates, percarbonates, etc., are preferably combined with bleach activators, which leads to in situ production in the aqueous solution (i.e., during the washing operation) of the peroxyacid corresponding to the bleach activator. Various non-limiting examples of activators are described in the U.S. patent. 4,915,854, issued April 10, 1990 to Mao et al., And the US patent. 4,412,934. Typical are the activators of nonanoyloxybenzenesulfonate (NOBS) and tetraacetylethylenediamine (TAED), and mixtures thereof can also be used. See also the patent of E.U.A. 4,634,551 for other typical bleaches and activators useful herein. The most preferred amide derivative bleach activators are those of the formulas: R 1 N (R 5) C (O) R 2 C (O) LO R 1 C (O) N (R 5) R 2 C (O) L wherein R 1 is an alkyl group which contains from 6 to 12 carbon atoms, R 2 is an alkylene containing from 1 to 6 carbon atoms, R 4 is H or alkyl, aryl or alkaryl containing from 1 to 10 carbon atoms and L is any suitable leaving group. A leaving group is any group that is displaced from the bleach activator as a consequence of the nucleophilic attack on the bleach activator by the perhydrolysis anion. A preferred leaving group is phenylsulfonate. Preferred examples of bleach activators of the above formulas include (6-octanamido-caproyl) -oxybenzene sulfonate, (6- nonanamidocaproyl) oxybenzenesulfonate, (6-decanamido-caproyl) oxybenzenesulfonate and mixtures thereof, as described in US Patent No. 4,634,551, which is incorporated herein by reference. Another class of bleach activators comprises activators of the benzoxazine type described by Hodge et al. In the U.S. Patent. No. 4,966,723, issued October 30, 1990, incorporated herein by reference. A highly preferred bleach activator of the benzoxazine type is: Yet another class of preferred bleach activators includes acyl-lactam activators, especially acylcaprolactams and acylvalerolactams of the formulas: wherein R6 is H or an alkyl, aryl, alkoxyaryl or alkaryl group containing from 1 to 12 carbon atoms. Highly preferred lactam activators include benzoylcaprolactam, octanoylcaprolactam, 3,5,5-trimethyl-hexanoylcaprolactam, nonanoylcaprolactam, decanoylcaprolactam, undequenoylcaprolactam, benzoylvalerolactam, octanoylvalerolactam, decanoylvalerolactam, undequenoyl-valerolactam, nonanoylvalerolactam, 3,5,5-trimethylhexanoyl-valerolactam and mixtures of the same. See also the U.S. Patent. No. 4,545,784 issued to Sanderson on October 8, 1985, incorporated herein by reference, which discloses acylcaprolactams, including benzoylcaprolactam, adsorbed to sodium perborate. Bleaching agents other than oxygen bleaching agents are also known in the art, and can be used herein. One type of bleaching agent that is not oxygen of particular interest includes photoactivated bleaching agents such as sulfonated zinc and / or aluminum phthalocyanines. See the patent of E.U.A. 4,033,718, issued July 5, 1977 to Holcombe et al. If used, the detergent compositions typically should contain from about 0.025% to about 1.25% by weight of said bleaches, especially zinc phthalocyaninesulfonate. If desired, the bleaching compounds can be catalyzed by means of a manganese compound. Such compounds are well known in the art and include, for example, the manganese-based catalysts described in the U.S.A. 5,246,621, the patent of E.U.A. 5,244,594; the patent of E.U.A. 5,194,416; the patent of E.U.A. 5,114,606; and European Patent Application Publication Nos. 549,271 A1, 549,272A1, 544,440A2, and 544,490A1. Preferred examples of these catalysts include Mnl 2 (uO) 3 (1, 4,7-trimethyl-1, 4,7-triazacyclononane) 2 (PF 6) 2 »Mn '" 2 (u-0) α (u-OAc) ) 2 (1, 4,7-trimethyl-1, 4,7-triazacyclononane) 2 (Cl 4) 2; MnlV 4 (u-0) 6 (1, 4,7-triazacyclononane) 4 (Cl 4) 4; (u-OAc) 2- (1, 4,7-trimethyl-1, 4,7-triazacyclononane) 2 (C104) 3, Mnlv (1, 4,7-trimethyl-1, 4,7-triazacyclononane) - (OCH 3) 3 (PF 6), and mixtures thereof. Other metal-based bleach catalysts include those described in the U.S. Patent. No. 4,430,243 and Patent of E.U.A. No. 5,114,611. The use of manganese with various complex ligands to improve bleaching is also reported in the following US Patents: 4,728,455; 5,284,944; 5,246,612; 5,256,779; 5,280,117; 5,274,147; 5,153,161; and 5,227,084. As a practical matter, and not by way of limitation, the compositions and methods of the present may be adjusted to provide on the order of at least one part per ten million of the active bleach catalyst species in the aqueous solution of washing, and will preferably provide about 0.1 ppm to 700 ppm, most preferably about 1 ppm to 500 ppm of the catalyst species in the wash solution.

Enzymes Enzymes may be included in the formulations herein for a wide variety of laundry purposes, including removal of protein-based, carbohydrate-based or triglyceride-based spots, for example; and for the prevention of transfer of refugee dyes and for the restoration of cloth. Enzymes to be incorporated include proteases, amylases, lipases, cellulases and peroxidases, as well as mixtures thereof. Other types of enzymes can also be included. They can be of any suitable origin such as plant, animal, bacterial, fungal or yeast origin. However, their choice is governed by several factors such as optimum pH-activity and / or stability, thermostability, stability against active detergents, improvers, and so on. In this regard, bacterial or fungal enzymes such as for example bacterial amylases and proteases and fungal cellulases are preferred. Enzymes are normally incorporated at levels sufficient to provide up to about 5 mg by weight, preferably about 0.01 mg to about 3 mg of active enzyme per gram of the composition. Stated otherwise, the compositions herein will usually comprise from about 0.001% to about 5%, preferably 0.01% -1% by weight, of a commercial enzyme preparation. Protease enzymes are usually present in such commercial preparations at levels sufficient to provide 0.005 to 0.1 Anson units (AU) of activity per gram of composition. Suitable examples of proteases are the subtilisins that are obtained from particular strains of B. Subtilis and β. Licheniformis. Another suitable protease is obtained from a strain of Bacillus that has maximum activity on the whole pH scale of 8 to 12, developed and sold by Novo Industries A / S under the brand name ESPERASE. The preparation of this enzyme and analogous enzymes is described in British Patent Specification No. 1, 243,784, by Novo. Proteolytic enzymes suitable for removing protein-based stains and which are commercially aable include those sold under the ALCALASE and SAVINASE brands of Novo Industries A / S (Denmark) and MAXATASE of International Bío-Synthetics, Inc. (The Netherlands). Other proteases include Protease A (see European Patent Application No. 130,756, published January 9, 1985) and Protease B (see European Patent Application Serial No. 87303761.8, filed on April 28, 1987, and the European Patent Application No. 130,756, by Bott et al., Published January 9, 1985). Amylases include, for example, the α-amylases described in British Patent Specification No. 1, 296,839 (Novo).; RAPIDASE, International Bio-Synthetics, Inc. and TERMAMYL, Novo Industries. The cellulases that can be used in the present invention, They include both bacterial and fungal cellulases. Preferably, they will have an optimum pH between 5 and 9.5. The patent of E.U.A. No. 4,435,307 of Barbesgoard et al., Issued March 6, 1984, describes suitable fungal cellulases produced from Humicola insolens and Humicola strain DSM 1800, or a cellulase-producing fungus 212 belonging to the genus Aeromonas, and cellulase extracted from the hepatopancreas of a marine mollusk (Dolabella Auricle Solander). Suitable cellulases are also described in the publications of GB-A-2,075,028; GB-A-2,095,275 and DE-OS-2,247,832. CAREZYME (Novo) is especially useful. Lipase enzymes suitable for detergent use include those produced by microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri ATCC 19,154, as described in British Patent 1, 372,034. See also lipases in Japanese Patent Application 53,20487, open to public inspection on February 24, 1978. This lipase is available from Amano Pharmaceutical Co. Ltd., Nagoya, Japan, under the trademark Lipasa P "Amano," referred to here as "Amano-P." Other commercial lipases include Amano-CES, Chromobacter viscosum lipases, for example, Chromobacter viscosum var. lipoliticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and also Chromobacter viscosum lipases from U.S. Biochemical Corp, E.U.A. and Disoynth Co., Netherlands and lipases from Pseudomonas gladioli. The LIPOLASE enzyme derived from Humicola lanuginosa and commercially available from Novo (see also EP 341, 947), is a preferred lipase for use herein. The peroxidase enzymes can be used in combination with oxygen sources, for example percarbonate, perborate, persulfate, hydrogen peroxide, etc. They are generally used for "solution bleaching", that is, to avoid the transfer of dyes or pigments removed from the substrates during washing operations to other substrates present in the washing solution. Peroxidase enzymes are known in the art and include, for example, horseradish peroxidase, ligninase and haloperoxidase such as chloroperoxidase and bromoperoxidase. Peroxidase-containing detergent compositions are described, for example, in the PCT International Application WO 89/099813, published October 19, 1989 by O. Kirk, awarded to Novo Industries A / S. A wide variety of enzyme materials and means for their incorporation in synthetic detergent compositions are also described in the U.S.A. 3,553,139, issued January 5, 1971 to McCarty et al. Additionally, enzymes are described in the U.S. patent. 4,101, 457, Place et al., Issued July 18, 1978, and in the patent of E.U.A. 4,507,219, Hughes, issued March 26, 1985. In the patent of E.U.A. 4,261, 868 de Hora et al., Issued April 14, 1981, describe useful enzyme materials for liquid detergent formulations, and their incorporation into said formulations. Enzymes, for use in detergents, can be stabilized by various techniques. Enzyme stabilization techniques are described and illustrated in the U.S. patent. 3,600,319, issued August 7, 1971 to Gedge et al., And in the publication of European Patent Application No. 0 199 405, Application No. 86200586.5, published on October 29, 1986, Venegas. Enzyme stabilization systems are also described, for example, in the U.S. patent. 3,519,570. Other components that are commonly used in detergent compositions, and that can be incorporated into detergent tablets, include chelating agents, soil removal agents, soil anti-redeposition agents, dispersing agents, suds suppressors, fabric softeners, water transfer inhibiting agents, coloring and perfumes. The compounds described above for a product are conveniently packaged in a packaging system. A flexible sheet packing system can be formed. Materials suitable for use as a flexible sheet include monolayer films, coextruded or laminated. Said films may comprise various components such as polyethylene, polypropylene, polystyrene, polyethylene terephthalate. Preferably, the packaging system is composed of a coextruded film of polyethylene and bioriented polypropylene with an MVTR of less than 5 g / day m2. The MVTR of the packaging system is preferably less than 10 g / day / m2, preferably less than 5 g / day / m2. The film (2) can have several thicknesses. The thickness should usually be between 10 and 150 μm, preferably between 20 and 100 μm, preferably between 25 and 80 μm, and between 30 and 40 μm is very preferred. A packaging material preferably comprises a barrier layer found regularly with packaging materials having a low oxygen transmission rate, regularly of less than 300 cm3 / m2 / day, preferably less than 150 cm3 / m2 / day, of preferably less than 100 cm3 / m2 / day, preferably less than 50 cm3 / m2 / day, and less than 10 cm3 / m2 / day is very preferred. Typical materials having such barrier properties include bioriented polypropylene, polyethylene terephthalate, Nylon, polyethylene vinyl alcohol, or laminated materials comprising one of these, as well as SiOx (silicon oxides), or thin sheets of metal, such as for example aluminum sheets. Said packaging material can have a beneficial influence on the stability of the product, for example during storage. Among the packaging methods used are usually the wrapping methods described in WO92 / 20593, which include ripple wrap or overwrap. When such methods are used, a longitudinal seal is provided, which may be a flap seal or an overlap seal, after which a first end of the packing system is closed with a first final seal, followed by the closing of the second end with a second final seal. The packaging system may comprise reclosure means such as those described in WO92 / 20593. In particular, using a twist, a cold seal or an adhesive is particularly suitable. In fact, a cold seal band or a band of adhesive, in a position adjacent to the second end of the packaging system, can be applied to the surface of the packaging system such that this band can provide both the initial seal and the seal. Reclosure of the packaging system. In such a case, the adhesive or cold seal band may correspond to a region having a cohesive surface, that is, a surface adhering only to another cohesive surface. These reclosing means may also comprise spacers that prevent unwanted adhesion. Such separators are described in WO95 / 13225, published on May 18, 1995. There may also be a plurality of spacers and a plurality of strips of adhesive material. The main requirement is that the communication between the exterior and the interior of the package is minimal, even after the first opening of the packaging system. A cold seal can be used, and in particular a cold seal grid, where the cold seal is adapted in order to facilitate the opening of the packaging system.

EXAMPLES EXAMPLE 1 i) A detergent base powder of composition A was prepared in the following manner: all the particulate material of the base composition was mixed in a mixing drum or in a spray drum to form a homogeneous particulate mixture, apart from the binder for spraying, the fluorescer or brightener and zinc photo-binder phthalocyaninesulfonate. Then, the particulate mixture was divided into two equal parts, one part to prepare a white layer, another part to prepare a green layer. The material of the white layer was obtained by spraying the brightener or fluorescer together with the binder half. The material of the green layer was obtained by spraying the zinc phthalocyaninesulfonate photoblanker together with the rest of the binder. The layers were then processed independently in a Loedige KM600®. ii) Using a Bonals® rotary press, both matrices were filled in two independent forced flow feeders. Both layers were compressed in the precompression and compression stations to form a double layer tablet. iii) In this particular example, the tablets had a square cross section of 45 mm on one side, a height of 24 mm and a weight of 45 g. The height of the lower green layer corresponded to 50% of the total height of the tablet. The tensile strength of the uncoated tablets was 5 kPa. iv) The tablet was then coated with 2.5 g of coating formed of 90% by weight of adipic acid and 10% by weight of CSM bentonite clay.

Ammonium agglomerates 1 comprises 40% anionic surfactant, 27% zeolite and 33% carbonate.

Anionic agglomerates 2 comprises 40% anionic surfactant, 28% zeolite and 32% carbonate. Nonionic agglomerate comprises 26% nonionic surfactant, 6% Lutensit K-HD 96, 40% anhydrous sodium acetate, 20% carbonate and 8% zeolite. Cationic agglomerates comprise 20% cationic surfactant, 56% zeolite and 24% sulfate. Stratified silicate comprises 95% SKS 6 and 5% silicate. Agglomerates of bleach activator comprises 81% TAED, 17% acrylic / maleic copolymer (acid form) and 2% water. Particles of sodium salt of ethylenediamine-N-disuccinic acid / sulfate comprise 58% sodium salt of ethylenediamine-N, N-disuccinic acid, 23% sulfate and 19% water. Foam suppressor comprises 11.5% silicone oil (from Dow Corning), 59% zeolite and 29.5% water. Binder system for spraying comprises 16% by weight of polymer of the following type: 68% by weight of PEG4000 and 16% by weight of DIBS (sodium diisoalkylbenzenesulfonate or sodium toluenesulfonate).

The following is another example of a composition that can be use: Anionic agglomerates 1 comprises 40% anionic surfactant, 27% zeolite and 33% carbonate. Anionic agglomerates 2 comprises 40% anionic surfactant, 28% zeolite and 32% carbonate. Nonionic agglomerate comprises 26% nonionic surfactant, 6% Lutensit K-HD 96, 40% anhydrous sodium acetate, 20% carbonate and 8% zeolite. Cationic agglomerates comprise 20% cationic surfactant, 56% zeolite and 24% sulfate. Stratified silicate comprises 95% SKS 6 and 5% silicate. Agglomerates of bleach activator comprises 81% TAED, 17% acrylic / maleic copolymer (acid form) and 2% water. Sodium salt particles of ethylenediamine-N, N-disuccinic acid / sulfate comprise 58% sodium salt of ethylenediamine-N, N-disuccinic acid, 23% sulfate and 19% water. Foam suppressor comprises 11.5% silicone oil (from Dow Corning), 59% zeolite and 29.5% water. Binder system for spraying comprises 16% by weight of polymer of the following type: 68% by weight of PEG4000 and 16% by weight of DIBS (sodium diisoalkylbenzenesulfonate or sodium toluenesulfonate). EXAMPLE 2 i) A detergent base powder of composition A was prepared in the following manner: all the particulate material of the base composition was mixed in a mixing drum or in a spray drum, to form a homogenous particulate mixture, apart from the binder system for spraying, the fluorescer or brightener and the photo-binder phthalocyaninesulfonate zinc. Then, the particulate mixture was divided into two equal parts, one part to prepare a white layer, another part to prepare a green layer. The material of the white layer was obtained by spraying the brightener or fluorescer together with the binder half. The material of the green layer was obtained by spraying the zinc phthalocyaninesulfonate photoblanker together with the rest of the binder. The layers were then processed independently in a Loedige KM 600®. ii) Using a Bonals® rotary press, both matrices were filled in two independent forced flow feeders. Both layers were compressed in the precompression and compression stations to form a double layer tablet. Ii) In this particular example, the tablets had a square cross section of 45 mm side, a height of 24 mm and a weight of 45 g. The height of the lower green layer corresponded to 50% of the total height of the tablet. The tensile strength of the uncoated tablets was 5 kPa. iv) The tablet was then coated with 2.5 g of coating formed of 89% by weight of adipic acid, 10% by weight of CSM bentonite clay, and 1% by weight of Coasol ™.

EXAMPLE 3 i) A detergent base powder of composition A was prepared in the following manner: all the particulate material of the base composition was mixed in a mixing drum or in a spray drum to form a homogeneous particulate mixture. Then the binder system was sprayed.

Subsequently, the powder was processed in a Loedige KM 600®. ii) Using an Instron® laboratory press, the matrix was filled with the detergent powder. The powder was compressed with a force such that the tensile strength of the tablet was 10 kPa. iii) In this particular example, the tablets had a diameter of 54 mm on the side, a height of 24 mm and a weight of 45 g. iv) The tablet was then coated with 2.5 g of coating formed of 90% by weight of adipic acid and 10% by weight of CSM bentonite clay.

EXAMPLE 4 i) A detergent base powder of composition A was prepared in the following manner: all the particulate material of the base composition was mixed in a mixing drum or in a spray drum to form a homogeneous particulate mixture. Then the binder system was sprayed.

Subsequently, the powder was processed in a Loedige KM 600®. ii) Using an Instron® laboratory press, the matrix was filled with the detergent powder. The powder was compressed with a force such that the tensile strength of the tablet was 10 kPa. iii) In this particular example, the tablets had a diameter of 54 mm on the side, a height of 24 mm and a weight of 45 g. Then, the tablet was coated with 2.5 g of coating formed of 89% by weight of adipic acid, 10% by weight of bentonite clay and 1% of Coasol ™.

EXAMPLE 5 i) A detergent base powder of composition A was prepared in the following manner: all the particulate material of the base composition was mixed in a mixing drum or in a spray drum to form a homogeneous particulate mixture. Then the binder system was sprayed.

Subsequently, the powder was processed in a Loedige KM 600®. ii) Using an Instron® laboratory press, the matrix was filled with the detergent powder. The powder was compressed with a force such that the tensile strength of the tablet was 10 kPa. iii) In this particular example, the tablets had a diameter of 54 mm on the side, a height of 24 mm and a weight of 45 g. Then, the tablet was coated with 2.5 g of coating formed of 87% by weight of adipic acid, 10% by weight of bentonite clay, 1% of Coasol ™ and 2% of Solka-Floc ™ 1016.

RESULTS It was observed that: For approximately 500 tablets made for each of the examples 1 and 2, when a coated tablet is completely immersed in 1 liter of tap water at 20 ° C, the coating disintegrates in about 8 seconds for the example 1, and in about 5 seconds for example 2. Further, it was observed that the tablets prepared according to example 1 had a cracked coating once the coating had crystallized, while the tablets prepared according to example 2 did not they quartered In addition, comparing 10 tablets prepared according to examples 3, 4 and 5, the following occurrence of coating cracks was observed: Example 3 Example 4 Example 5 Occurrence of cracks 100% 20% 0% (10 kPa tablets when not coated)

Claims (1)

1 NOVELTY OF THE INVENTION CLAIMS

1- A coated detergent tablet, characterized in that the coating comprises a component that is liquid at 25 ° C. 2. The coated detergent tablet according to claim 1, further characterized in that the coating also comprises a crystallized structure. 3. The coated detergent tablet according to claim 2, further characterized in that the material forming the crystallized structure is a dicarboxylic acid. 4. The coated detergent tablet according to claim 3, further characterized in that the coating consists essentially of adipic acid. 5. The detergent tablet coated according to claim 4, further characterized in that the coating also comprises a clay. 6. The coated detergent tablet according to claim 1, further characterized in that the coating also comprises reinforcing fibers. 7. A method for preparing a tablet as claimed in any of the preceding claims, characterized in that it comprises the steps of (a) forming a core by compressing a particulate material comprising surfactant and builder; (b) applying a coating material to the core, the coating material being in molten form; (c) allowing the molten coating material to solidify; wherein the coating material comprises a component that is liquid at 25 ° C. 8. A method for preparing a tablet as claimed in any of claims 1 to 6, comprising the steps of: (a) forming a core by compressing a particulate material comprising surfactant and builder; (b) applying a coating material to the core, the coating material being dissolved in a solvent or water; (c) allow the solvent or water to evaporate; wherein the coating material comprises a component that is liquid at 25 ° C. 9. The process according to any of claims 7 or 8, wherein the coating material, or the mixture of materials, has a melting point of at least 145 ° C, the coating comprising a clay.