FR2926088A1 - Detergent tablet, useful e.g. in dishwasher devices, comprises five superimposed layers with three layers having different compositions, phosphate, active enzymes, detergent additives, surfactants and bleaching agents - Google Patents

Abstract

Detergent tablet comprises five superimposed layers with at least three layers having different compositions. An independent claim is included for a process for preparing a tablet comprising forming the mixtures corresponding to the compositions respective of five layers of the tablet, depositing the mixture (on a support) corresponding to the composition of the first layer and formation of the first layer by compression, depositing the mixture (on the first layer) corresponds to the composition of the second layer and formation of the second layer by compression of the formed combination, depositing the mixture (on the second layer) corresponds to the composition of the third layer and formation of the third layer by compression of the formed combination, depositing the mixture (on the third layer) corresponds to the composition of the fourth layer and formation of the fourth layer by compression of the formed combination, and depositing the mixture (on the fourth layer) corresponds to the composition of the fifth layer and formation of the fifth layer by compression of the formed combination.

Description

Multilayer detergent tablet

FIELD OF THE INVENTION The present invention relates to the field of detergent compositions in the form of tablets. These detergent tablets are intended to be used in appliances of the dishwasher or washing machine type for cleaning items of dishes or laundry respectively.

STATE OF THE ART Various types of dishwashing detergent compositions are known, such as powders or dishwashing liquids whose quantity is measured by the consumer who places them in the dispenser of said dishwasher. This type of packaging is unsatisfactory insofar as the consumer uses too little or too much powder or liquid, thus leading to either a bad washing or an overconsumption of products. To facilitate the use of these detergent compositions and to improve the storage conditions, it has been proposed to package them in tablet form. These detergent tablets were first monolayer, consisting of a mixture of components such as bleaches, enzymes, detergency builders, etc. However, monolayer tablets have the disadvantage of leading to the uncontrolled dissolution of the components depending on the selected cycle and the washing temperature. This type of system therefore does not separate the actions of the various components of the tablet and does not allow washing and rinsing the elements to be cleaned. It has therefore been proposed tablets comprising two or even three superimposed layers, so as to separate certain compounds to prevent them from acting at the same time in the wash cycle. It has even been proposed to add a central insert to possibly use an additional composition. If such tablets allow a physical separation of certain components, this separation is not complete and they can interact especially during storage tablets. In addition, tablets lose strength, especially when a central insert is used, which is a major drawback for storage and transport tablets.

Non-phosphate detergent tablets (ie tablets containing less than 4% phosphates) are being used more and more today, especially to reduce water pollution. However, phosphate-free detergent tablets having two or three layers are difficult to implement because they have lower breaking strengths than tablets containing phosphates in large quantities (typically 30%). Pelleting additives such as binders are therefore generally added to tablets without phosphate or containing less than 4% of phosphates in order to improve their cohesion, which is disadvantageous, in particular because the industrial manufacturing process is complicated. An object of the present invention is therefore to provide a detergent tablet to solve at least one of the aforementioned drawbacks, as well as an associated manufacturing method. In particular, an object of the present invention is to provide a detergent tablet, and a related manufacturing method, having a high impact resistance, that this tablet is with or without phosphate. Another object of the present invention is to provide a detergent tablet, and an associated manufacturing method, having an increased chemical resistance, thus improving its stability during storage.

Yet another object of the present invention is to provide a detergent tablet, and an associated manufacturing method, allowing a controlled and fine dissolution of the components according to the selected cycle and the washing temperature.

SUMMARY OF THE INVENTION For this purpose, there is provided a detergent tablet characterized in that it comprises five layers superimposed on each other, with at least three layers among the five layers having different compositions.

Preferred but nonlimiting aspects of this detergent tablet are as follows: the detergent tablet has a mass of between 15 and 30 grams, preferably between 18 and 25 grams; the detergent tablet has a height of between 5 and 50 mm, preferably between 10 and 30 mm; the detergent tablet has a height of between 1 and 20 mm, preferably between 1 and 10 mm; the detergent tablet has a breaking strength of between 70 and 180 Newton, preferably between 80 and 150 Newton; the detergent tablet has a density of between 1 and 5 g / cm 3; the detergent tablet comprises less than 4% by weight of phosphates, the percentage by weight being relative to the total mass of the tablet; the detergent tablet comprises: between 0.003 and 2% by weight of active enzymes; between 10 and 99% by weight of detergency builders, preferably between 30 and 70% by weight; o between 0.05 and 40% by weight of surfactants, preferably between 1 and 25% by weight, and more preferably between 1 and 5% by weight; o between 1 and 30% by weight of bleaching agents, preferably between 5 and 20% by weight; o between 0.5 and 10% by weight of bleach activators, preferably between 1 and 5% by weight, where the percentages by weight being relative to the total mass of the tablet. the three layers having different compositions respectively comprise a bleaching agent, an activator of the bleaching agent, and enzymes for forming an enzymatic system; the layer comprising the enzymes is not in contact with the layer comprising the bleaching agent, and the layer comprising the bleaching agent is not in contact with the layer comprising the activator of the bleaching agent ; the detergent tablet further comprises rinsing additives to form a rinsing system, and protective additives to form a system for protecting the elements to be cleaned with the detergent tablet; the detergent tablet comprises one or two layers having a bleaching agent; each of the five layers has a different composition, the five layers respectively comprising the bleaching agent, the activator of the bleaching agent, the enzymes, the rinsing additives, and the protective additives; the detergent tablet comprises a layer having a disintegration time of less than 7 minutes and a layer having a disintegration time greater than 7 minutes; the layer having a disintegration time of less than 7 minutes is the layer forming the enzymatic system, the layer forming the enzymatic system preferably comprising bursting agents to accelerate the disintegration of the layer; the layer having a disintegration time greater than 7 minutes is the layer forming the rinsing system, the layer forming the rinsing system preferably comprising retarding agents for slowing the disintegration of the layer.

According to another aspect of the invention, there is provided a method of manufacturing this detergent tablet, this method comprising the following successive steps: - Formation of mixtures corresponding to the respective compositions of the five layers of the tablet; Deposition on a support of the mixture corresponding to the composition of the first layer, and formation of the first layer by compression; - Deposition on the first layer of the mixture corresponding to the composition of the second layer, and formation of the second layer by compression of the formed assembly; - Deposition on the second layer of the mixture corresponding to the composition of the third layer, and formation of the third layer by compression of the formed assembly; - Deposition on the third layer of the mixture corresponding to the composition of the fourth layer, and formation of the fourth layer by compression of the formed assembly; - Deposition on the fourth layer of the mixture corresponding to the composition of the fifth layer, and formation of the fifth layer by compression of the formed assembly.

Preferably, the formation of the first, second, third and fourth layers is carried out by compressing the assembly formed at a compression value of between 1000 kN / m 2 and 10000 kN / m 2, in that the formation of the fifth This layer is produced by compressing the assembly formed at a compression value of between 8000 kN / m 2 and 25000 kN / m 2. DESCRIPTION OF THE FIGURES Other features and advantages of the invention will become apparent from the description which follows. which is purely illustrative and not limiting and should be read in conjunction with the accompanying drawings, in which Figure 1 is a graph illustrating the washing cycle of the dishwasher used to test the performance of the detergent tablet.

DETAILED DESCRIPTION OF THE INVENTION The following detailed description is made with reference to a detergent tablet adapted for use in a dishwasher for cleaning dishes. However, the corresponding teaching could easily be adapted by those skilled in the art so that the detergent tablet can be used in a washing machine; in particular, the compositions of the different layers should be modified to correspond to the desired active ingredients.

The detergent tablet of the invention consists of a stack of five layers which are superimposed on each other, thus forming a uniform and compact block. The tablet has a cylindrical shape with a section having any shape, generally circular, oval, octagonal, or parallelepipedic. When the section of the tablet is parallelepiped, typically square or rectangular, the corners of the tablet can be curved so that they are less brittle. Each of the layers has the same section so that the stack it forms is uniform. In particular, the lateral surfaces of the layers are straight, the lateral surfaces of the adjacent layers being preferably contiguous so that the edge of the tablet is continuous. This avoids in particular having lateral unhitching between two successive layers, these unplugging having in general a detrimental effect on the mechanical stability of the tablet during handling operation for example. Each layer has a height of between 1 and 20 mm, and preferably between 1 and 10 mm. It is not mandatory that the five layers have an identical height even if it is preferred. The detergent tablet has a total height of between 5 and 50 mm, preferably between 10 and 30 mm. The detergent tablet further has a mass of between 15 and 30 grams, preferably between 18 and 25 grams, and a density of between 1 and 5 g / cm3.

In the case of a detergent tablet for a washing machine, the mass may be between 15 and 45 grams (density between 1 and 5 g / cm3). The five-layer tablet presented thus has a simple shape and dimensions that increase its mechanical resistivity since the salient points are reduced to a minimum. Such a detergent tablet has in fact a breaking strength of between 70 and 180 Newton, preferably between 80 and 150 Newton.

The mechanical strength of the tablet is also obtained through the manufacturing process implemented, which consists in progressively forming a complex of several layers, and in compacting this complex with each new layer addition so as to solidify it. As will be seen in more detail later, the tablet comprises at least three layers having different compositions. The first step is therefore to mix the components intended to form the compositions corresponding to each of the layers. It is then necessary to deposit the mixture corresponding to the first layer on a support, or in a mold having the desired section, then to compact the mixture to form the first layer.

The mixture corresponding to the second layer is then deposited on the first layer, and the assembly is compressed to form a first complex comprising the first and second layers. In the same way, for the third, fourth and fifth layers, the corresponding mixture is deposited on the complex formed in the preceding step and the whole is compressed to obtain a new complex with an additional layer. The compression forces used for formation of the first, second, third and fourth layers are between 1000 kN / m2 and 10000 kN / m2. The compressive force applied at the end, when forming the fifth layer, is greater, between 8000 kN / m2 and 25000 kN / m2, so as to increase the overall cohesion and strength of the tablet. This manufacturing process strengthens the detergent tablet that offers increased impact resistance. In addition, when producing tablets without phosphorus, it is not necessary to add any additive to enhance the stability of the tablet which is particularly advantageous.

In addition to the advantages associated with the physical structure of the five-layer tablet shown here, this detergent tablet also benefits from its chemical structure, especially its stability or efficiency during washing.

To obtain a tablet that is both chemically stable and effective, which allows in particular a fine sequenced dissolution of components, it is advisable to design the tablet with the following two constraints. The first requirement is to put in different layers the components that will have to act at different times during the washing cycle considered. This leads to having several layers of different compositions in the same tablet. It is also appropriate to remove as far as possible the compositions which are incompatible with each other from a chemical stability point of view. During the storage phases, there may indeed be unwanted interactions between certain components of adjacent layers. It is therefore necessary to move these components away from each other to minimize the corresponding interactions. In a detergent tablet, there are at least two components that it is better not to interact. In a five-layer tablet with at least three layers having a different composition, it is thus possible to separate the layers comprising the components not to come into contact with an intermediate layer of a different composition. The chemical structure of the tablet is determined by responding as much as can be done to these constraints that will guarantee the quality of the tablet. A dishwashing detergent tablet comprises a number of components which will be explained in more detail here, without being limiting.

Enzymes To enable the degradation of soil on the dishes, the tablet must contain enzymes of the protease, amylase, and optionally lipase type which form what is called an enzymatic system. These enzymes are generally in the form of granules that contain a certain amount of active enzymes. The detergent tablets according to the invention have an overall composition incorporating enzymes whose total amount of active enzymes is between 0.003 and 2% by weight. The percentages by weight indicated here and in the rest of the document are taken relative to the total mass of the composition of the tablet. Amylases can be used to decompose starch-based stains. Stainzym 12T (registered trademark of Novozymes, Copenhagen, Denmark) and / or Stainzym plus 12T (registered trademark) produced and distributed by Novozymes (registered trademark) and / or Purastar OXAM 8000E (registered trademark) produced and distributed by Genencor International (registered trademark) may be used. Stainzym 12T and Stainzym plus 12T are sold as granules and contain 1.4% active enzymes. Purastar OXAM 8000E is also sold as granules and contains 5.2 to 5.8% active enzymes. The tablet may also contain proteases to act on proteinaceous spots such as meat and eggs. Ovozyme 64T (registered trademark) produced and distributed by Novozymes and / or Purafect OX 8000D (registered trademark) produced and distributed by Genencor International may be used in the present invention. These enzymes are sold in granular form, Ovozyme 64T comprising 8.6% active enzymes, and Purafect OX 8000D comprising 10 to 12% active enzymes. The tablet may also contain lipases to improve the degradation of grease stains on the dishes. One can for example use the Lipex 100 (registered trademark) produced and distributed by Novozymes.

Bleaching agents and bleaching activators To enable the degradation of oxidizable stains such as tea, coffee, red wine, the tablet must contain a bleaching agent, that is a substance capable of oxidizing directly or indirectly the described organic compounds. The bleaching agents may therefore be of the sodium perborate mono or tetrahydrate type, sodium percarbonate, sodium persilicate, and sodium persulfate. In alkaline medium, these compounds release hydrogen peroxide in contact with water, thus generating a source of active oxygen. The tablet comprises between 1 and 30% of bleaching agents, preferably between 5 and 20%.

To enable even more effective dishwashing, the tablet must contain a tetraacetylenediamine (TAED), pentaacetylglucose (PAG), tetraacetylglycoluryl (TAGU) and sodium benzoyloxybenzene sulfonate bleach activator. These activators react in the wash bath with hydrogen peroxide, giving chemical compounds whose performance on organic soils is higher, especially for reasons of chemical affinity.

The tablet comprises between 0.5 and 10% activator of the bleaching agent, preferably between 1 and 5%. Preferably, the tablet comprises a ratio of bleaching agents to bleach activators corresponding to a molar ratio of 4 to 1, preferably a molar ratio of 2 to 1.

Detergent additives (or builders) The effectiveness of the wash will be increased if the tablet further comprises detergency builders, also called builders. The detergency builders trap metal ions such as calcium and magnesium present in the wash solution by complexation, ion exchange or precipitation. When a detergency builder is present, it is in an amount generally between 10 and 99% by weight, preferably between 30 and 70% by weight. Non-phosphorus water soluble builders can be organic or inorganic. Inorganic compounds that may be present include zeolites, phyllosilicates, alkali metal carbonates (usually sodium), and sodium silicates; while organic compounds include polycarboxylate polymers such as polyacrylates, acrylic / maleic copolymers and acrylic phosphonates, monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, mono-, di- and tri-succinates glycerol, carboxymethyloxysuccinates, amino polycarboxylic compounds (such as methyl glycinediacetic acid carboxymethyloxymalonates), dipicolinates, nitrilotriacetates and hydroxyethyliminodi acetates. The class of water-soluble phosphorus adjuvants includes orthophosphates, methaphosphates, pyrophosphates and alkali metal polyphosphates. Specific examples of inorganic phosphate detergent builders include sodium and potassium tripolyphosphates, orthophosphates and hexametaphosphates. Sodium tripolyphosphate is a particularly preferred phosphorus adjuvant for dishwasher tablets. It exists in hydrated, anhydrous or partially hydrated form, and mixtures of these forms can be used to regulate the disintegration and dissolution rate of the tablet. The levels of these additives which can lead to the release of phosphate in fluvial waters with a resulting trophic effect are preferably restricted to a level of less than 4% by weight in the tablet.

To allow efficient washing of the dishes, the pH of the wash solution must be at least 9 and preferably between 9.5 and 12.5. Most detergency builders are alkaline, so there is no need to add other compounds to the tablet to adjust the pH. If this is not the case, it is preferable that the tablet include components for adjusting the pH of the wash solution to between 9.5 and 12.5.

Surfactants To enable efficient washing, the tablet must contain one or more nonionic surfactants, preferably low foaming nonionic surfactants. The surfactants are amphiphilic molecules, which are composed of an apolar lipophilic part and a polar hydrophilic part.

For dishwashing detergent tablets, the amount of surfactant in the tablet is between 0.05 and 15% by weight, and preferably between 1 and 5% by weight. Surfactants in solid form are easier to use in tablets which also have solid compositions. However, when the surfactant is in liquid form, it can also be introduced into the tablet, in which case it is adsorbed on supports such as sodium carbonate or silica.

The synthetic nonionic surfactants may be generally defined as compounds derived from the condensation between alkylene oxide groups and hydrophobic organic compounds, which may be aliphatic or aromatic. The length of the hydrophilic portion of the surfactant can be easily adjusted to obtain a water-soluble compound having the desired HLB, the HLB translating the degree of hydrophilicity or lipophilicity of the surfactant.

The non-exhaustive list of nonionic surfactants that can be used in the tablet includes ethoxylated and / or propoxylated fatty alcohols, copolymers of ethylene oxide and propylene oxide, and alkyl polyglucosides.

The ethoxylated and / or propoxylated fatty alcohols result from the condensation between a chain of polyethylene oxide and / or propylene oxide with a fatty alcohol. The ethoxylated and / or propoxylated fatty alcohols may be linear, branched, saturated or unsaturated, and may contain about 6 to 24 carbon atoms and about 5 to 50 ethylene oxide and / or propylene oxide units. Lauryl alcohol, myristic alcohol are fatty alcohols that can be used in the desired detergent tablet. The nonionic surfactants of the Genapol (trademark) type produced by Clariant (registered trademark) may be used and more particularly the nonionic surfactant sold under the name Genapol EP 2544 (C12 / C15, 40E / 4OP).

The polyethylene oxide groups represent at least 40% of the block copolymer. The compounds generally have a molecular weight of about 2,000 to 10,000, and preferably about 3,000 to 6,000. BASF Pluronic surfactants can be used, for example, in this invention.

The alkyl polyglucosides (AGP) are readily biodegradable and can be used in dishwasher tablet compositions. The surfactants of the type Glucopon (trademark) of Cognis (registered trademark) may for example be used in the desired detergent tablet and more particularly the nonionic surfactant marketed under the name Glucopon 50G.

It is also possible to use anionic surfactants, especially in the case of detergent tablets for washing machines. In this case, the amount of surfactants in the tablet is between 0.05 and 40% by weight, and preferably between 5 and 25% by weight.

The non-exhaustive list of anionic surfactants that can be used in laundry detergent tablets includes alkyl benzene sulfonates, paraffin or alkane sulfonates, primary alcohol sulfates, alpha-sulphonates, alkyl ether sulphates, sulphosuccinates, acyl isethionates, methyl ester sulphonates, soap fatty acid sulfoalkylamides, diglycolamide sulfates, N-acyl amino acids, and alkyl polyoxyethylene carboxylates.

Sodium sulfopon sodium alkylates (trademark) produced by Cognis (registered trademark) can be used in the desired detergent tablet and more particularly the anionic surfactants marketed under the name Sulfopon 1218 G and Sulfopon 1216 G.

Soaps can also be used in the tablet and more particularly the soap marketed under the name Trepalbé PC20P 86% produced by Christeyns (trademark).

Complementary Components In addition to these basic components of the detergent tablet, this may include additional components that will be used according to the desired specificities of the detergent tablet.

For example, rinse additives, such as surfactants and chelating agents, can be used to form a final phase rinse system after the cleaning agents used.

Protective additives may also be used, such as, for example, benzotriazole and zinc salts. These protective additives form a dishwasher and dishwasher protection system against unwanted chemical attack from any of the tablet components.

Dyes can also be added to differentiate the layers from one another. These dyes are essentially intended to improve the aesthetic appearance of the tablet vis-à-vis the consumer. The amount of dye in the tablet is in this case between 0.01 and 0.15% by weight, preferably between 0.01 and 0.1% by weight. Chelating agents for trapping metal ions may also be present in the composition. They are also known as sequestering or metal ion complexing agents. If necessary, it is preferable that the amount of chelating agents is of the order of 0.5 to 5% by weight. Preferred chelating agents include organic phosphonates, amino carboxylates, polyfunctionally substituted compounds, and mixtures thereof. It is also possible to use homopolymers of acrylic acid or copolymers of acrylic and maleic acid. Particularly preferred chelating agents are organic phosphonates such as alpha-hydroxy-2-phenylethyl diphosphonate, ethylene diphosphonate, hydroxyl-1,1-hexylidene, vinylidene-1,1-diphosphonate, 1,2-dihydroxyethane 1,1-diphosphonate and hydroxyethylene 1,1-diphosphonate. Hydroxyethyl 1,1-diphosphonate, 2-phosphono-1,2,4-butanetricarboxylic acid or their salts are particularly preferred.

It is also generally used bursting agents, or delaying agents, which are respectively intended to accelerate or slow down the disintegration of the layer in which they are incorporated. By disintegrating a layer is meant the separation of the various components constituting said layer with respect to the layer which is adjacent to it and the dissolution of these components. A method of measuring disintegration time is described in detail below.

All the components presented above serve as a basis for the composition of the detergent tablet. They are distributed in the various layers forming the tablet according to the constraints mentioned above, that is to say avoid and possibly remove components that must not interact with each other during storage of the tablet. In the case of a dishwashing detergent tablet, it is particularly sought to move the layer forming the enzymatic system away from the layer comprising the bleaching agents. For example, a layer comprising the rinsing system may be interposed between a layer comprising the enzymes and a layer comprising the bleaching agents. The different components are also distributed according to the desired disintegration sequence. In particular, it is desirable that the rinsing system be activated at the end of the wash cycle, or at least after the action of cleaning agents such as the enzyme system. To do so, the layer forming the rinsing system should include the retarding agents necessary to retard the dissolution. It can further be provided that the rinsing system forms a particular layer, placed in the center of the five-layer tablet, so that it can not be dissolved until the layers surrounding it have dissolved. Among the four layers surrounding the layer forming the rinsing system, there will be for example an enzymatic system-forming layer, a layer comprising the bleaching agents and a layer comprising the bleach activators. Preferably, the tablet will be formed so that the layer forming the enzyme system and the layer forming the rinsing system have respectively a disintegration time of less than and greater than 7 minutes.

The disintegration time is determined by the following method: a beaker filled with 5 liters of tap water with a hardness of 7-15 ° TH is used (the water hardness is given by the hydrotimetric titre measured in ° TH, with 1 ° THE10mg.1- 'CaCO3) at 55 ° C with a stirring speed of 150 rpm. The stirring is obtained using a mechanical stirrer and a stirring blade. The detergent tablet is placed in a basket which is then introduced into the beaker of water while triggering the stopwatch. The time is recorded on the stopwatch each time a layer of the pellet is totally dissolved, which corresponds to the disintegration time of said layer. It is also possible to note the pH of the water during dissolution of the pellet by means of a pH meter. All disintegration times reported herein are measured by the method just described. In a particular embodiment of the invention, the five layers of the detergent tablet all have different compositions. They may for example comprise respectively the enzymes, the bleach activator, the bleaching agent, the rinsing additives, and the protective additives. In addition to these basic components, each of the layers may further comprise surfactants, builders, sequestering agents, bursting agents or retarding agents depending on the desired disintegration of the layer, and possibly dyes.

As already indicated, it is preferred that the layer forming the enzyme system not be in contact with the layer comprising the bleaching agent. This makes it possible to avoid chemical interactions between the enzyme system and the bleaching agents, which increases the chemical stability of the tablet and consequently improves its storage. For the same reasons, it may be expedient for the layer comprising the bleaching agent not to be in contact with the layer comprising the bleach activator.

From a disintegration sequence point of view, it is preferable that the layer forming the enzymatic system is one of the two outer layers of the tablet. In the same way, as already mentioned, the layer forming the rinsing system is preferably the middle layer of the stack formed by the five superimposed layers.

According to a preferred embodiment, the detergent tablet comprises the five aforementioned layers, these layers being superimposed in the following order: layer forming the enzymatic system, then layer comprising the activator of the bleaching agent, then - layer forming the rinsing system, then - layer comprising the bleaching agent, then - layer forming the protection system. It should be noted that protective additives can be added in several layers of the tablet.

We will now give some examples of dishwashing detergent tablets having five layers, with different compositions, and a layer order also different, with the disintegration times of each of the layers.

Example 1 Example 1 corresponds to a phosphate-free tablet with two layers containing a bleaching agent. The order of the layers and the composition of each of the layers of the tablet is given in Table 1 below. In this table, the quantities of each component are given as a percentage by mass relative to the mass of the layer in question.

Table 1 Layers Components Percentage by mass in each protease layer 5.4 (active enzymes: 0.46%) amylase 2.9 (active enzymes: 0.041%) Nonionic surfactant 2.4 Layer 1: silica 1.3 Layer containing acrylic homopolymer 12.2 enzymatic system Sodium bicarbonate 21.7 Carbonate sodium 23.2 Sodium silicate 15.1 Sodium citrate 6.6 cellulose 9 dye 0.2 benzotriazole 1 phosphonate 4.9 Layer 2: Sodium silicate containing 19.5 polymer and zinc salt Layer containing sodium bicarbonate 10.7 protective additives of sodium silicate 13.7 lava -dishes and nonionic surfactant 4.6 dishes, and a portion of silica 2.4 bleaching agent Sodium percarbonate 34.2 Cellulose 8.3 perfume 0.5 dye 0.2 Layer 3: Sodium percarbonate 39 Layer containing sodium bicarbonate 13.1 part of the bleaching agent Polyethylene glycol 7.7 Sodium citrate 40.2 Polyethylene glycol 9.8 Sodium carbonate dense 8.8 Ca light sodium soda 8.8 Sodium bicarbonate 19.5 Layer 4: Sodium silicate containing a 21.7 Layer containing the polymer rinsing system Sodium citrate 21 Nonionic surfactant 3.2 silica 1.6 phosphonate 5.5 dye 0.1 TAED 14.6 Sodium bicarbonate 21.9 Sodium carbonate dense 4.9 Layer 5: Light sodium carbonate 4.9 Layer containing Sodium citrate 22.2 Sodium silicate agent activator containing a 18.3 polymer bleaching Nonionic surfactant 3.6 Silica 1.7 Polyethylene glycol 5.5 Cellulose 2.4 The weight of each layer of the pellet is 4.1 grams.

The hardness of the tablets, measured using a MTS Synergy 100 durometer 500N / C (registered trademark), is 80-110 Newton.

The dissolution times of each of the layers, measured with the method described above, are shown in Table 2 below.

Table 2 Layers Dissolution time pH (minutes) p T = 0 0 7.40 Layer 1 containing system 4 9.71 enzymatic Layer 2 containing additives 6 9.78 for protection of the dishwasher and dishes and part of the bleaching agent Layer 3 Containing a Part 9.8 of the Bleach Layer 4 Containing the Rinse System 9.9 Layer 5 Containing the Activator 8 9.69 of the Bleaching Agent The sequential dissolution of the layers of the tablet is noted. The layer containing the enzyme system has a dissolution time of less than 7 minutes and the layer containing the rinsing system has a dissolution time greater than 7 minutes.

Example 2: Example 2 corresponds to a phosphate-free tablet with a single layer containing the bleaching agent. The order of the layers and the composition of each of the layers of the tablet is given in Table 3 below. In this table, the quantities of each component are given as a percentage by mass relative to the mass of the layer in question. Table 3 Layers Components Percentage by weight in each protease layer 5.4 (active enzymes: 0.46%) Amylase 2.9 (active enzymes: 0.041%) Nonionic surfactant 2.4 Layer 1: Silica 1.3 Layer containing Acrylic Homopolymer 12.2 Enzymatic System Sodium bicarbonate 21.7 Sodium carbonate 23.2 Sodium silicate 15.1 Sodium citrate 6.6 cellulose 9 dye 0.2 benzotriazole 1 phosphonate 4.9 Layer 2: Sodium silicate containing 19.5 polymer and zinc salt Layer containing sodium bicarbonate 11.3 protection additives Sodium Silicate 13.7 Dishwasher and Sodium Citrate 33.6 Tableware Nonionic Surfactant 4.6 Silica 2.4 Cellulose 8.3 Fragrance 0.5 Dye 0.2 Layer 3: Sodium Percarbonate 73.2 Layer containing Sodium Bicarbonate Agent 12.5 Bleaching Polyethylene Glycol 7.7 Citrate Sodium 6.6 Polyethylene glycol 9.8 Sodium carbonate, dense 8.8 Sodium carbonate, mild 8.8 Sodium bicarbonate m 19.5 Layer 4: Sodium silicate containing a 21.7 Layer containing the polymer rinsing system Sodium citrate 21 Nonionic surfactant 3.2 silica 1.6 phosphonate 5.5 dye 0.1 TAED 14.6 Sodium bicarbonate 21.9 Sodium carbonate dense 4.9 Layer 5: Light sodium carbonate 4.9 Layer containing Sodium citrate 22.2 Sodium silicate activator containing 18.3 polymer bleaching Nonionic surfactant 3.6 silica 1.7 Polyethylene glycol 5.5 Cellulose 2.4 The weight of each layer of the pellet is 4.1 grams. The hardness of the tablets, measured using a MTS Synergy 100 durometer 500N / C (registered trademark), is 90-110 Newton.

The dissolution times of each of the layers, measured with the method described above, are shown in Table 4 below.

Table 4 Layers Dissolution time pH (minutes) p T = 0 0 7.49 Layer 1 containing the system 3 9.75 enzymatic Layer 2 containing the additives 9 9.84 protection of the dishwasher and the dishes Layer 3 containing the agent of 12min30 9.85 bleaching Layer 4 containing the 11 min30 9.83 rinsing system Layer 5 containing the activator 6 9.75 of the bleaching agent The sequential dissolution of the layers of the tablet is noted again. The layer containing the enzyme system has a dissolution time of less than 7 minutes and the layer containing the rinsing system has a dissolution time greater than 7 minutes.

Example 3: Example 3 corresponds to a phosphate-free tablet with a single layer containing the bleaching agent. The order of the layers and the composition of each of the layers of the tablet is given in Table 5 below. In this table, the quantities of each component are given as a percentage by mass relative to the mass of the layer in question. Table 5 Layers Components Percentage by weight in each protease layer 5.4 (active enzymes: 0.46%) Amylase 2.9 (active enzymes: 0.041%) Nonionic surfactant 2.4 Layer 1: Silica 1.3 Layer containing Acrylic Homopolymer 12.2 Enzyme System Sodium Bicarbonate 21.7 Sodium carbonate 23.2 Sodium silicate 15.1 Sodium citrate 6.6 Cellulose 9 Coloring 0.2 TAED 14.6 Sodium bicarbonate 21.9 Sodium carbonate dense 4.9 Layer 2: Light sodium carbonate 4.9 Layer containing sodium citrate 22.2 Activator of silicate agent of sodium containing a 18.3 polymer bleaching Nonionic surfactant 3.6 silica 1.7 Polyethylene glycol 5.5 Cellulose 2.4 Polyethylene glycol 9.8 Sodium carbonate dense 8.8 Sodium carbonate light 8.8 Sodium bicarbonate 19.5 Layer 3: Sodium silicate containing a 21.7 Layer containing the polymer system of rinsing Sodium citrate 21 Nonionic surfactant 3.2 silica 1.6 phosphonate 5.5 color ant 0.1 Layer 4: Sodium Percarbonate 73.2 Layer containing Sodium Bicarbonate 12.5 Bleaching Polyethylene Glycol 7.7 Sodium Citrate 6.6 Benzotriazole 1 Phosphonate 4.9 Layer 5: Sodium silicate containing 19.5 polymer and zinc salt Layer containing Bicarbonate sodium 11.3 protective additives Sodium silicate 13.7 dishwasher and sodium citrate 33.6 tableware Nonionic surfactant 4.6 silica 2.4 Cellulose 8.3 perfume 0.5 dye 0.2 The weight of each layer of the pellet is 4.1 grams. The hardness of the tablets, measured using a MTS Synergy 100 durometer 500N / C (registered trademark), is 100-110 Newton. The dissolution times of each of the layers, measured with the method described above, are shown in Table 6 below.

Table 6 Layers Dissolution time p Fi (minutes) T = 0 0 7.40 Layer 1 containing the enzymatic system 9.65 Layer 2 containing the activator 9.91 of the bleach Layer 3 containing the 9min3O 9.91 flushing system Layer 4 containing The bleaching agent Layer 5 containing the dishwasher and dishwashing additives 2min3O 9.65 Once again the sequential dissolution of the layers of the tablet is noted. The layer containing the enzyme system has a dissolution time of less than 7 minutes and the layer containing the rinsing system has a dissolution time greater than 7 minutes.

In this configuration of the tablet, the enzymatic layer is separated from the layer containing the bleaching agent by the layer containing the rinsing system and the layer containing the bleach activator. In addition, the layer containing the activator of the bleaching agent is not in contact with the layer containing the bleaching agent. This configuration makes it possible to obtain better stability of the tablet during storage. This tablet also has good washing performance.

As indicated above, the tablet preferably comprises from 0.003 to 2% by weight (based on the total mass of the tablet) of active enzymes.

There are a number of tests for quantifying the amount of active enzymes present in a detergent tablet, for example from the monitoring of its washing efficiency. We will describe below a particular test to measure this enzymatic activity from different types of soiling. This test is carried out on a Vedette brand dishwasher, model VLA 830, with the Modul'up program whose steps are as follows: - Wash at 50 ° C (4.7L) for 20min, then - Rinse cold (4.6L) for 5min, then - Hot rinse (4.4L) for 20min, then - Dry for 15min.

Figure 1 is a graph illustrating the evolution of temperature during this wash program.

The test is carried out in hard water at 15 ° TH and with a dirt ballast. Standardized dirt plates (supplier Center For Testmaterials BV) are used. These are resin plates on which soil is deposited. Seven soils are used to study several types of stains, and therefore the effectiveness of enzymes and bleach: - Oxidizable stains: tea (ref: DM 11), red wine (Ref: DM 51), - Amylaceous stains : maizena (ref: DM 76), rice (ref: DM 78), - Protein stains: egg (ref: DM 21), egg-milk (ref: DM 31), meat (ref: 25 DM 91). The plates are then stored in the dishwasher. Two plates of each soiling are used each time. Each plate is measured using a spectrocolorimeter (Mercury portable spectrophotometer SN1130 (registered trademark)) before washing 30 and at the end of the dishwasher program. The measured colorimetric differences (AE *) make it possible to evaluate the efficacy of the protease on proteinaceous spots, the amylase efficacy on starchy stains and the effectiveness of the bleaching agent on oxidizable stains. For a given spot, the greater the color differences, the more the tablet comprises corresponding active enzymes. The spectrocolorimeter determines the Cartesian coordinates of the light emitted by the observed object, namely: - L *: clarity (-sheight / light +) - scale from 0 to 100, - the component a * (- green / red +) - scale from -100 to +100, - component b * (- blue / yellow +) - scale from -100 to +100. The device gives the colorimetric coordinates of the plate before washing (standard) then the washed plate (sample). The knowledge of the 3 magnitudes (L *, a *, b *) makes it possible to calculate the color difference between the sample and the standard according to the following formula: DE * = V (OL *) 2 + (Da *) 2 + (Ab *) 2 For each sample, an average value of AE * is determined over several measurements. The test that has just been described has been carried out with several detergent tablets in which the layer forming the enzyme system has been modified so as to vary the amount of active enzymes.

The tablet used corresponds to the tablet of Example 3 described above. Only the composition of layer 1 comprising the enzyme system has been modified, so as to have respectively 0% of enzymes, 0.05% of enzymes, 0.5% of enzymes, and 5% of enzymes (examples 4 to 7), these percentages being percentages by weight relative to the total mass of the tablet.

The exact compositions of the layer 1 comprising the enzyme system for each example are summarized in Table 7 below: Table 7 Components Percentage by weight in the layer the layer containing the enzyme system Example 4 Example 5 Example 6 Example 7 Protease 0 (Enzymes 0.16 (enzymes 1.62 (enzymes 16.26 (active enzymes: 0) active: 0.014) active: 0.14) active: 1.4) amylase 0 (enzymes 0.09 (enzymes 0.87 (enzymes 8.75 (active enzymes: 0) active: 0.0013) active: 0.012) active: 0.12) Nonionic surfactant 2.4 2.4 2.4 2.44 ionic silica 1.3 1.34 1.3 1.325 Continued from Table 7 Components Percentage by mass in the layer the layer containing the enzyme system Example 4 Example 5 Example 6 Example 7 Homopolymer 12.2 12. 2 12.2 12.2 Acrylic Bicarbonate 21.7 21.7 21.7 21.7 sodium Carbonate 31.4 31.2 29 6.44 sodium Sodium silicate 15.2 15.11 15.11 15.11 Sodium citrate 6.6 6.6 6.6 6.6 cellulose 9 9 9 9 coloring 0.2 0.2 0.2 0.2 Efficiency The washing action of the tablet on the various soil stains is summarized in Table 8 below: Table 8 Milk-milk spots Meat Rice Mayzena Enzyme analyzed Amylase 4E Protease * Example 4 5.42 6.23 9.26 11.42 10.93 4E * Example 5 6.43 7.59 10.15 13.76 11.67 4E * Example 6 10.61 7.8 13.45 24.93 22.76 4E * Example 7 33.81 25.29 14.60 62.68 66.62 This test makes it possible to evaluate the active enzyme content of the tablet 10 since the result is even more important than the quantity active enzymes is great. In particular, a very important efficiency is observed for Examples 6 and 7, which respectively correspond to tablets comprising 0.5 and 5% by weight of enzymes, ie approximately 0.03 and 0.3% by weight of active enzymes. It is furthermore noted with Example 5, which corresponds to a tablet comprising 0.05% by weight of enzymes, ie approximately 0.003% by weight of active enzymes, that the efficacy test presented makes it possible to qualify and to quantify the enzymatic activity of the tablet despite the very small amount of active enzymes present in the tablet.

The reader will understand that many changes can be made without materially escaping the new lessons and benefits described here. Therefore, all modifications of this type are intended to be incorporated within the scope of the five-layer detergent tablet according to the invention, and its manufacturing method.

Claims (9)

A detergent tablet characterized in that it comprises five layers superimposed on each other, with at least three layers among the five layers having different compositions. 2. Detergent tablet according to claim 1, characterized in that it has a mass of between 15 and 30 grams, preferably between 18 and 25 grams. 3. Detergent tablet according to any one of claims 1 or 2, characterized in that it has a height of between 5 and 50 mm, preferably between 10 and 30 mm. 4. Detergent tablet according to any one of claims 1 to 3, characterized in that each layer has a height of between 1 and 20 mm, preferably between 1 and 10 mm. 5. A detergent tablet according to any one of claims 1 to 4, characterized in that it has a breaking strength between 70 and 180 Newton, preferably between 80 and 150 Newton. 6. Detergent tablet according to any one of claims 1 to 5, characterized in that it has a density of between 1 and 5 g / cm3. 7. Detergent tablet according to any one of claims 1 to 6, characterized in that it comprises less than 4% by weight of phosphates, the percentage by weight being relative to the total mass of the tablet. 8. Detergent tablet according to any one of claims 1 to 7, characterized in that it comprises: - between 0.003 and 2% by weight of active enzymes; between 10 and 99% by weight of detergency builders, preferably between 30 and 70% by weight; between 0.05 and 40% by weight of surfactants, preferably between 1 and 25% by weight, and more preferably between 1 and 5% by weight; from 1 to 30% by weight of bleaching agents, preferably from 5 to 20% by weight; From 0.5 to 10% by weight of bleach activators, preferably from 1 to 5% by weight, the percentages by weight being relative to the total mass of the tablet. 9. A detergent tablet according to any one of claims 1 to 8, characterized in that the three layers having different compositions respectively comprise a bleaching agent, a bleach activator, and enzymes to form a system. enzymatique.1O.A detergent tablet according to claim 9, characterized in that the layer comprising the enzymes is not in contact with the layer comprising the bleaching agent, and in that the layer comprising the bleaching agent does not is not in contact with the layer comprising the activator of the bleaching agent. 11.Detergent tablet according to any one of claims 9 or 10, characterized in that it further comprises rinsing additives to form a rinsing system, and protective additives to form a protective system of the elements to be cleaned with the detergent tablet. 12. A detergent tablet according to any one of claims 9 to 11, characterized in that it comprises one or two layers having a bleaching agent. 13. A detergent tablet according to claim 11, characterized in that each of the five layers has a different composition, the five layers respectively comprising the bleaching agent, the bleach activator, the enzymes, the additives rinsing, and protective additives. 14.Tablet according to any one of claims 1 to 13, characterized in that it comprises a layer having a disintegration time of less than 7 minutes and a layer having a disintegration time greater than 7 minutes. 15. A detergent tablet according to claim 14 taken in combination with any one of claims 9 to 13, characterized in that the layer having a disintegration time of less than 7 minutes is the layer forming the enzymatic system. 16. A detergent tablet according to claim 15, characterized in that the layer forming the enzyme system comprises bursting agents to accelerate the disintegration of the layer. 17. A detergent tablet according to any one of claims 14 to 16 taken in combination with any one of claims 11 to 13, characterized in that the layer having a disintegration time greater than 7 minutes is the layer forming the system. rinsing. 18. A detergent tablet according to claim 17, characterized in that the layer forming the rinsing system comprises retarding agents for slowing the disintegration of the layer. 19. A method of manufacturing a detergent tablet according to any one of the preceding claims comprising the following successive steps: - Formation of the mixtures corresponding to the respective compositions of the five layers of the tablet - Depositing on a support of the mixture corresponding to the composition of the first layer, and formation of the first layer by compression; - Deposition on the first layer of the mixture corresponding to the composition of the second layer, and formation of the second layer by compression of the formed assembly; - Deposition on the second layer of the mixture corresponding to the composition of the third layer, and formation of the third layer by compression of the formed assembly; - Deposition on the third layer of the mixture corresponding to the composition of the fourth layer, and formation of the fourth layer by compression of the formed assembly; - Deposition on the fourth layer of the mixture corresponding to the composition of the fifth layer, and formation of the fifth layer by compression of the formed assembly. 20. The method of claim 19, characterized in that the formation of the first, second, third and fourth layers is achieved by compression of the assembly formed at a compression value of between 1000 kN / m2 and 10000 kN / m2, in that the formation of the fifth layer is achieved by compressing the formed assembly to a compression value of between 8000 kN / m2 and 25000 kN / m2.