New coated detergent tablet

Abstract

The present invention relates to the field of tablets for household and fabric care, in particular detergent tablets. The invention relates in particular to a tablet coated with an environmentally friendly solution based on a mixture of polymers of natural origin, which makes it possible to prevent the tablets from breaking or flaking during production, transportation and use thereof.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of household and fabric cleaning tablets, and in particular detergent tablets. The invention relates in particular to a tablet coated with an environmentally friendly solution based on a mixture of polymers of natural origin which prevents these tablets from fracturing or flaking during their manufacture, transport and use. STATE OF THE ART

[0002] Detergent tablets offer many advantages over other liquid or powder detergents, particularly with regard to their dosage, storage, and transportation. Detergent tablets are most often prepared by premixing various components, preferably in powder or granular form, but also in liquid form. This premix is ​​then compacted using a press to form a tablet. Industrially, rotary presses are preferably used to enable the formation of compacted tablets at high speeds.

[0003] These pre-dosed tablets are introduced into a washing machine (typically a dishwasher or washing machine) at the start of a wash cycle, and are generally intended to be fully consumed by the end of the cycle.

[0004] The field of detergents imposes particular constraints for forming tablets since some components do not withstand compression well, other components can react with each other before use and thus reduce the effectiveness of the tablet during use. This is why multi-layer tablets have been developed. Indeed, such multi-layer tablets allow both the separation of components likely to react with each other, and the compression-sensitive components to be compressed only once by inserting them in the last layer. Multi-layer tablets may have slightly delayed disintegration between the different layers, the first layer having been compressed several times thus generally has a longer disintegration time than the following less compressed layers.

[0005] Although they offer many advantages, such as minimal bulk and maximum efficiency, detergent tablets are quite fragile. One of the recurring issues is the durability of these tablets over time, particularly so that they can be handled and transported without disintegrating or crumbling.

[0006] Detergent tablets are particularly susceptible to damage when dropped on the floor.

[0007] It has therefore been proposed to provide detergent tablets with packaging, generally individual, in order to improve their mechanical properties of resistance to abrasion and impact. Such packaging must act as a physical barrier in order to preserve the integrity of the contents of the package, for example against moisture damage or against damage due to handling of the tablets.

[0008] In this regard, it has been proposed to cover detergent tablets with water-soluble packaging: either by a thermoplastic film which can be retracted or not; or by spraying a solution forming a thin film, which is also called "coating" according to the Anglo-Saxon term.

[0009] Teachings relating to "coating" are found in a patent of the company Colgate Palmolive published in 1966 under the reference US 3,231,505. It is proposed to coat the detergent tablet with a solution of synthetic organic polymer, for example polyvinyl alcohol (PVA), forming a film in order to increase the resistance to abrasion and accidental breakage of the tablet. Another patent, in the name of Dalli-Werke GmbH and Co.

[0010] KG, published under reference EP 2 045 319, describes a spray-coated detergent composition for which the coating is achieved by placing a powder coating material in direct contact with the tablet and then leveling the powder particles so that a homogeneous "melted" coating is obtained. Also known is the applicant's patent FR3044678 which proposes to greatly improve the efficiency of the packaging of detergent tablets by "coating" by adding a specific agent aimed at improving the rinsing efficiency. The patent of the company Procter and Gamble WO 01 / 64829 also describes detergent tablets coated with a "coating" improving the mechanical characteristics of said tablet and its dissolution.

[0011] However, known water-soluble detergent tablet packaging does not provide complete satisfaction in terms of ease and efficiency of use, particularly when it is made from bio-sourced materials. The following issues have been identified: appearance of undissolved residues in significant quantities at the end of the wash, in the internal space of the washing machine; increase in the dissolution time of the detergent tablet, or the disintegration time, which lengthens the duration of the wash cycle; sticking effect: the tablets adhere to each other and are difficult for the consumer to separate; appearance of cracking in the coating during storage of the tablets.

[0012] Thus, none of the detergent tablet packaging available on the market and obtained from polymers of natural origin achieves a satisfactory compromise between preserving the physical integrity of the tablet on the one hand, and its effectiveness on the other.

[0013] A need therefore remains for the provision of coated tablets that overcome the problems of the prior art, in particular for the provision of tablets coated using a mixture of naturally occurring polymers whose strength is improved so that the tablets do not fracture or chip during their manufacture, transport and use. An additional objective is to ensure that tablets packaged with more environmentally friendly bio-sourced polymers do not adhere to each other, and are easily separable, for example when stacked on top of each other or against each other in a storage space. Particular attention is also paid to the dissolution and disintegration time of the tablet, the desired absence of undissolved residues, and the preservation of the effectiveness of the product contained in the tablet. SUMMARY OF THE INVENTION

[0014] The invention relates to a coated tablet for household and fabric maintenance with a water-soluble coating obtained by spraying a solution comprising a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein, water and optionally a humectant, the bio-sourced protein film-forming agent being chosen from plant proteins, animal proteins and mixtures thereof.

[0015] The present invention more particularly relates to a coated tablet for household and fabric maintenance comprising a body formed from compacted powder, the body being coated with a water-soluble coating comprising: a) a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein, said protein being chosen from animal proteins, vegetable proteins and their mixtures, the mass proportion of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%; b) optionally a humectant; c) water; in which the mass ratio (bio-sourced film-forming agent / humectant) is between 1 and 30, ideally between 2 and 20 when the humectant is present.

[0016] The present invention also relates to a method of manufacturing a coated tablet for household cleaning and tissues comprising a body coated with a water-soluble coating, said method comprising the following steps: (1) providing a body formed from compacted powder; (2) spraying onto the surface of the body a solution comprising: a) from 2% by mass to 80% by mass of a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein relative to the total mass of the solution, said protein being chosen from animal proteins, vegetable proteins and their mixtures, the mass proportion of proteins in said bio-sourced film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%; b) at least 20% by mass of water relative to the total mass of the solution; and c) optionally, a humectant; the mass ratio (bio-sourced film-forming agent / humectant) in said solution being between 1 and 30 when the humectant is present.

[0017] Other aspects of the invention are as described below and in the claims. DETAILED DESCRIPTION OF THE INVENTION

[0018] The inventors have developed tablets meeting the expressed needs. As such, the present invention relates to a coated tablet for household and fabric maintenance comprising a body formed from compacted powder, said body being coated with a water-soluble coating obtained by spraying onto the surface of said body a solution comprising: a) from 2% to 80% by mass or from 5% to 70% by mass, preferably from 30% to 70% or from 30% to 50% by mass, of a bio-sourced film-forming agent consisting of the mixture of a polysaccharide, preferably a starch, and at least one protein relative to the total mass of the solution, said protein being chosen from animal proteins, vegetable proteins and their mixtures and the mass proportion of proteins in said bio-sourced film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, even more preferably from 2% to 20%; b) at least 20% or at least 30%, preferably at least 50%, by mass of water relative to the total mass of the solution; and c) optionally, a humectant; the mass ratio (bio-sourced film-forming agent / humectant) in said solution being between 1 and 30 when the humectant is present.

[0019] The term "household and fabric care tablet" as used herein refers to compositions in compacted solid form for household and fabric care.

[0020] The compacted solid compositions consist of a set of particles grouped together and having sufficient cohesion to be able to be handled without being broken and which disintegrate easily in water. One or more of these tablets, when added to a prescribed quantity of water, provide a solution suitable for carrying out a household cleaning operation, such as for example the cleaning of floors, walls, bathroom or kitchen surfaces, dishes or a cleaning or laundry care operation. The tablets can be used for example for the preparation of a refill solution for household products ("refill tablet"). Thus, the household and fabric care tablets can be tablets suitable for washing clothes, dishes or any other household cleaning operation which involves dissolving the tablet in an aqueous medium.Such tablets may be referred to by the generic term "detergent tablet". Fabric care tablets may in particular be tablets intended for washing laundry or for laundry care ("softening tablet").

[0021] The tablets do not require high hardness, their cohesion and mechanical resistance being notably reinforced by the use of a coating which covers the tablet, that is to say adheres to the surface of the tablet.

[0022] It has been found, surprisingly, that a tablet for household and fabric care, in particular a detergent tablet, coated with the coating of the invention is very satisfactory in terms of washing efficiency, disintegration time, absence of washing residues, as well as ease of storage. In addition, the coated tablet thus produced does not adhere to other tablets or other elements present in contact with it. Furthermore, no cracking is observed in the coating coating during storage of the tablets, only a few small cracks can sometimes be observed for high protein mass concentrations. The integrity of the tablet is therefore preserved, the coating does not come apart.

[0023] The coating obtained according to the invention very effectively protects the tablet against abrasion and impacts, as well as against moisture damage and damage due to handling of said tablet.

[0024] Moreover, such a solution is environmentally friendly.

[0025] The manufacture of such a tablet therefore does not require the use of a thermoplastic film but simply the use of a particular solution, to form the water-soluble coating intended to cover the surface of the tablet by simple spraying. The tablet for household and fabric maintenance can be a coated detergent tablet, in particular a detergent tablet for dishwashers.

[0026] The various components of the proposed tablet may be as described below. Body

[0027] The tablet has a body formed by compacting powder. It is understood that the expression "body formed from compacted powder" does not exclude the possibility that the body includes liquids. Typically, the body is formed by a mixture of raw materials in solid form (powder) and possibly one or more raw materials in liquid form.

[0028] For the purposes of the present invention, the term "powder" means a material in the form of solid particles. The term powder therefore includes, within the scope of the present invention, materials in the form of granules.

[0029] The tablet body may consist of a single layer or a stack of several layers that are superimposed on each other, thus forming a uniform and compact block. For a multi-layer tablet, the different layers may have the same or different composition.

[0030] The body of the tablet preferably has an elongated shape with a cross-section having any shape, for example circular, oval, octagonal, or parallelepiped. When the cross-section of the tablet is parallelepiped, typically square or rectangular, the corners of the tablet may be curved so that they are less brittle.

[0031] The body of detergent tablets is generally made up of a mixture of components exerting different actions, these components being able, for example, to be chosen from surfactants, fillers, sequestrants, bleaching agents, enzymes, bleaching activators, alkaline agents, polymers, perfumes, colorants, tableting additives (binders, lubricants), descaling agents, corrosion inhibitors, catalysts, bursting agents...

[0032] The tablet preferably has a mass ranging from 1 gram to 100 grams, preferably from 5 grams to 50 grams. The tablet preferably has a mechanical resistance ranging from 5 Newtons to 300 Newtons, preferably from 10 Newtons to 90 Newtons. Water-soluble coating and spray solution

[0033] The water-soluble coating is obtained by spraying a solution comprising a bio-sourced film-forming agent, water and optionally a humectant. Once the sprayed solution has dried, the outer surfaces of the tablet body are completely covered with a thin water-soluble film (the water-soluble coating), also called "coating", adhering to the surface of the tablet. Bio-sourced film-forming agent

[0034] The bio-sourced film-forming agent consists of a mixture of a polysaccharide, preferably a starch, and at least one protein, the protein being chosen from plant proteins, animal proteins and mixtures thereof. It is understood that the animal proteins may be in the form of mixtures of different animal proteins and that the plant proteins may be in the form of mixtures of different plant proteins.

[0035] The polysaccharides and proteins useful in the context of the present invention are typically water-dispersible or water-soluble compounds. In particular, the polysaccharides and proteins useful in the context of the present invention are typically water-soluble at the tablet usage temperatures (typically 30 to 60°C).

[0036] Examples of animal proteins include, but are not limited to, lactoproteins (such as casein), albumins, and globulins. Animal proteins can be extracted from milk, eggs, or insect proteins.

[0037] Examples of plant proteins include, but are not limited to, albumins, globulins, prolamins, glutelins, and mixtures thereof. In particular, plant proteins useful in the present invention include gluten. Gluten is comprised of prolamins and glutelins.

[0038] Plant proteins can be extracted from a wide variety of plants, including algae.

[0039] In certain embodiments, the bio-sourced film-forming agent consists of a mixture of a polysaccharide, preferably a starch, and at least one protein, the protein being chosen from plant proteins and the mass proportion of proteins in the film-forming agent is greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%. In these embodiments, the protein(s) is / are therefore a plant protein / plant proteins. In other words, in these embodiments, the bio-sourced film-forming agent consists of a mixture of a polysaccharide, preferably a starch, and one or more plant proteins, the mass proportion of plant proteins in the film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%.

[0040] In certain embodiments, the bio-sourced film-forming agent is therefore advantageously composed of a mixture of a polysaccharide, preferably a starch, and at least one protein chosen from lacto proteins, albumins, globulins, prolamins, glutelins and mixtures thereof. In the context of the invention, the bio-sourced film-forming agent will preferably be 100% of plant origin.

[0041] In certain embodiments, the bio-sourced film-forming agent consists of a mixture of a starch and at least one plant protein chosen from albumins, globulins, prolamins, glutelins and mixtures thereof, preferably gluten.

[0042] In some embodiments, the bio-based film-forming agent consists of the mixture of starch and gluten.

[0043] It is well known to those skilled in the art that polysaccharides, sometimes called complex carbohydrates, are polymers made up of several sugars linked together by osidic bonds. Among the most widespread polysaccharides in the plant kingdom are starches (wheat starch, corn starch, etc.). Starch is a polysaccharide, namely a natural polymer, composed of D-glucose units. It serves as a reserve for higher plants and is a common element of the human diet, found in flours, among other things.

[0044] The spray solution comprises from 2% to 80% by mass or from 5% to 70%, preferably from 30 to 70%, by mass of a bio-sourced film-forming agent as described above. The mass proportion of proteins in the bio-sourced film-forming agent is greater than or equal to 1% and less than 50%, preferably it varies from 1% to 30%, preferably from 2% to 20%.

[0045] In some embodiments, the water-soluble coating and / or solution do not include a film-forming agent other than the bio-based film-forming agent.

[0046] In some embodiments, the solution may comprise, in addition to the bio-based film-forming agent, a conventional film-forming agent. Humectant

[0047] The humectant is optional. The humectant is typically chosen from polyols such as, for example, glycerin or sorbitol or mannitol, certain sugars and their derivatives and (poly)ethylene glycols and their combinations. In the context of the present invention, the sugar may in particular be a monosaccharide (e.g., fructose, glucose, dextrose, etc.), a disaccharide (e.g., sucrose, also called saccharose, for example in the form of cane sugar), or a mixture thereof (for example in the form of agave syrup). Preferably, the humectant is glycerin, advantageously of plant origin.

[0048] When the solution includes a humectant, the mass ratio (bio-sourced film-forming agent / humectant) in the solution is between 1 and 30, advantageously between 2 and 20.

[0049] In certain preferred embodiments, the humectant is used in a proportion of less than 10% by mass relative to the total mass of the solution, advantageously less than 5%. Other optional ingredients

[0050] The water-soluble coating may include conventional additional ingredients. Thus, these conventional additional ingredients may be added to the spray solution. When such conventional additional ingredients are present, their total mass does not exceed 10% of the mass of the solution. Examples of these ingredients include: thixotropic agents, anti-spotting and / or anti-filming agents, preservatives, surfactants and polymers (PVA, etc.), perfumes and colorants, etc.

[0051] Thus in certain embodiments, the solution comprises: a) from 2% to 80% by mass or from 5% to 70% by mass, preferably from 30% to 70% by mass relative to the total mass of the solution, of a biosourced film-forming agent consisting of the mixture of a polysaccharide, preferably a starch, and at least one protein relative to the total mass of the solution, the mass proportion of proteins in said biosourced film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, preferably from 2% to 20%; b) at least 20%, preferably at least 50%, by mass of water relative to the total mass of the solution; c) from 0 to 10% by mass of a humectant relative to the total mass of the solution; (d) from 0 to 10% by mass of conventional ingredients, such as the above-mentioned ingredients, relative to the total mass of the solution; the sum of the percentages of components (a) to (d) being equal to 100%.

[0052] When the humectant is used, the mass ratio (bio-sourced film-forming agent / humectant) in the solution is between 1 and 30, advantageously between 2 and 20.

[0053] The thickness of the coating deposited on the surface of the body of the tablet after drying is, for example, between 0.05 µm and 1000 µm, preferably between 5 µm and 300 µm, and more preferably between 15 µm and 200 µm. The water-soluble coating deposited on the body of the tablet, before drying, preferably represents between 0.3% and 20% of the total mass of the detergent tablet, and more preferably between 2% and 10% of the total mass of the detergent tablet.

[0054] The water-soluble coating after drying, for example the water-soluble coating of tablets ready for packaging and marketing or the coating of packaged tablets, includes: a) a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein, said protein being chosen from animal proteins, vegetable proteins and their mixtures, the mass proportion of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, preferably from 2% to 20%; b) water; c) optionally a humectant; in which the mass ratio (bio-sourced film-forming agent / humectant) is between 1 and 30, ideally between 2 and 20 when the humectant is present.

[0055] Depending on the drying carried out, the water-soluble coating after drying can comprise from 5% to 60% water by mass relative to the mass of the water-soluble coating.

[0056] In other words, the coated tablets of the present invention comprise: (1) a body formed from compacted powder; (2) a water-soluble coating, typically sprayed onto the surface of the body, the water-soluble coating comprising: a) a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein relative to the total mass of the solution, said protein being chosen from animal proteins, vegetable proteins and mixtures thereof, the mass proportion of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, preferably from 2% to 20%; b) water; c) optionally a humectant; in which the mass ratio (bio-sourced film-forming agent / humectant) is between 1 and 30, ideally between 2 and 20 when the humectant is present.

[0057] Depending on the drying carried out, the water-soluble coating after drying can comprise from 5% to 60% water by mass relative to the mass of the water-soluble coating.

[0058] In the coated tablets of the present invention, the proteins are preferably vegetable proteins (one vegetable protein or a mixture of different vegetable proteins). Making a tablet

[0059] The present invention also relates to a method of manufacturing a coated tablet as previously described, said tablet comprising a body formed from compacted powder, the body being coated with a water-soluble coating. The method comprises a step of spraying onto the surface of the body a solution comprising: a) from 2% to 80% by mass or from 5% by mass to 70% by mass, preferably from 30% to 70% by mass or from 30% to 50% by mass, of a biosourced film-forming agent consisting of the mixture of a polysaccharide, preferably a starch, and at least one protein, relative to the total mass of the solution, said protein being chosen from animal proteins, vegetable proteins and their mixtures, the mass proportion of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, preferably from 2% to 20%; b) optionally a humectant; and c) at least 20% by mass or at least 30%, preferably at least 50%, of water relative to the total mass of the solution; in which the mass ratio (bio-sourced protein film-forming agent / humectant agent) is between 1 and 30, advantageously between 2 and 20 when the humectant agent is present.

[0060] In other words, the present invention relates to a method of manufacturing a detergent tablet coated with a water-soluble coating, the method comprising the following steps: (1) providing a tablet body formed from compacted powder; (2) spraying onto the surface of the body a solution comprising: a) from 2% to 80% by mass or from 5% to 70% by mass, preferably from 30% to 70% by mass or from 30% to 50% by mass, of a bio-sourced film-forming agent consisting of a mixture of a polysaccharide, preferably a starch, and at least one protein, relative to the total mass of the solution, said protein being chosen from animal proteins, vegetable proteins and mixtures thereof, the mass proportion of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%, preferably from 2% to 20%; b) at least 20% or at least 30%, preferably at least 50%, by mass of water relative to the total mass of the solution; and c) optionally, a humectant. in which the mass ratio (bio-sourced protein film-forming agent / humectant agent) is between 1 and 30, advantageously between 2 and 20 when the humectant agent is present.

[0061] The solution may be as described in more detail above.

[0062] The solution may be sprayed in one or more times. The total quantity of solution sprayed may vary from 25g / m 2< to 1000g / m 2< , in particular from 100g / m 2< to 350g / m 2< taking into account the surface area of ​​the detergent tablet to be coated. For example, 0.6g of solution may be used to coat a 16g rectangular detergent tablet having a surface area to be coated of 3397 mm 2< .

[0063] Spraying is typically performed at room temperature using a nozzle system.

[0064] The method may further comprise one or more drying steps. Drying may be carried out using hot or unheated air or, for example, infrared radiation. Drying is typically carried out so that the tablet is dry to the touch. Preferably, drying results in a reduction of the mass of the sprayed solution by half (evaporation of some or all of the water).

[0065] In some embodiments, the method comprises one, two, three, or more succession(s) of spraying and drying steps.

[0066] After drying, the coated tablet can be packaged.

[0067] The present invention also relates to coated tablets obtainable by such methods.

[0068] The following examples are given for illustrative purposes. They should in no way be considered as limiting the present invention. EXAMPLES Example 1: Preparation of spray solutions

[0069] The coating solutions produced for all the tests presented below were formulated from the following raw materials: bio-sourced film-forming agent: “algae”: composition derived from algae comprising 95% by weight of starch and 5% by weight of protein “flour”: wheat flour comprising 12% by weight of gluten “starch”: potato starch “gluten”: wheat gluten humectant: glycerin of plant origin; preservative: potassium sorbate.

[0070] The production of the coated tablets, the operating conditions of which are detailed in the table below, was carried out as follows: Firstly, the preservative is dissolved in water at room temperature, under mechanical stirring using a propeller stirrer at an average speed of 500 revolutions per minute.

[0071] Once its total dissolution is observed, the bio-sourced film-forming agent is in turn dissolved in the mixture obtained previously.

[0072] Finally, glycerin (when present) is added to the mixture obtained, and mechanical stirring is maintained for a period of 5 min to ensure good dispersion of the glycerin within the solution thus formed.

[0073] The following spray solutions (Table 1) were prepared: Table 1: Spray solutions. Percentages are expressed by mass relative to the total mass of the solution. Spray solutions INV1 INV2 INV3 INV4 INV5 INV6 HI1 HI2 HI3 Vegetable protein (%) Gluten 1 Gluten 3.9 Gluten 8.5 Algae 42 Algae 42 Flour 37.7 - Gluten 21.25 Gluten 21.25 Starch (%) Starch 41.5 Starch 39 Starch 34 Starch 42.5 Starch 21.25 Starch 21.25 Humectant (%) 4 4 4 4 - 4 4 4 - Water (%) 51 50,6 51,6 51,5 55,5 55,8 51 51 55 Conservative (%) 2,5 2,5 2,5 2,5 2,5 2,5 2,5 2,5 2,5 Example 2: Spraying the solution to coat the tablet

[0074] The tablet is first placed on a perforated grid, then a first spraying phase is carried out using an air gun on the 5 visible faces of said tablet: the settings are such that the dosage presented in the tables below is deposited on the surface of the tablet.

[0075] This is followed by a drying step carried out in an oven set to a temperature of 37°C, for a duration of 15 minutes.

[0076] Once the drying operation is completed, the tablet is turned over and sprayed again on the 5 visible sides: the sides of the tablet are therefore sprayed twice, so as to ultimately receive the same quantity of solution as on the flat sides.

[0077] Finally, the drying operation is repeated in an oven at 37°C, for a further 15 minutes: the quality of the drying is then checked by simply touching the coated tablet, which must not be damp. Example 3: Characteristics of coated tablets 3.1 Analysis methods 3.1.1 Disintegration time

[0078] The disintegration time of the tablets was measured at short intervals after coating and drying of the tablets (t0) and after accelerated aging of the tablets under conditions simulating two years of storage under user conditions (4 weeks at 38°C with a relative humidity of 46% are equivalent to 2 years at room temperature and humidity).

[0079] The disintegration time of a tablet is measured using equipment that moves back and forth at a frequency of 60 strokes / min. The tablet is placed in a basket with multiple holes to allow water to drain. The basket is then immersed in a beaker containing a volume of 1.8L of water at 30°C. The disintegration time is recorded once the tablet is completely disintegrated, and there is no more tablet residue in the basket.

[0080] In order to be considered "compliant", the disintegration time of a dishwasher detergent tablet must be less than 15 minutes in order to obtain optimal washing efficiency.

[0081] In order to be considered "compliant", the disintegration time of a washing machine detergent tablet must be less than 10 minutes in order to obtain optimal washing efficiency.

[0082] In order to be considered "compliant", the disintegration time of a fabric softener tablet for washing machines must be greater than 15 minutes in order to obtain optimal washing efficiency. 3.1.2 Hardness

[0083] The hardness (strength) of the tablets was measured at short intervals after coating and drying of the tablets (t0) and after accelerated aging of the tablets under conditions simulating two-year aging.

[0084] Tablet hardness is measured using a durometer. A force is applied to the tablet using a jack, and its corresponding resistance is displayed directly in Newtons via a data processing system. This resistance varies from one type of tablet to another. 3.1.3 Friability

[0085] The friability of the tablets was measured at short intervals after coating and drying of the tablets (t0) and after accelerated aging of the tablets under conditions simulating two years of aging under user conditions.

[0086] Tablet friability is measured by placing 3 tablets in a closed plastic wheel. The rotation of the wheel reproduces the shocks of the reproduction line packaging. Tablet fragility is measured by weighing the tablets after 50 rotations. Friability is the percentage of mass loss before / after testing. 3.1.4 General appearance

[0087] The general appearance of the tablet is assessed at the end of the tablet drying operation at t0.

[0088] A visual assessment allows you to check the presence or absence of cracking of the coating, characterized by the presence of cracks on the surface of the tablet.

[0089] A simple touch assessment allows the surface of the tablet to be characterized (smooth, grainy, dusty, non-dusty). 3.2 Results 3.2.1 Dishwasher detergent tablet

[0090] To test the characteristics of the coated detergent tablets according to the invention, coating tests according to the method described above were carried out in the laboratory on three-layer detergent tablets of mass 16 g, rectangular shape and dimensions 36 mm (length) x 26 mm (width) x 12 mm (thickness), for use in dishwashers, manufactured using a rotary press. The compositions of layers 1, 2 and 3 are presented respectively in Tables 2 to 4. Table 2: Composition of layer 1 Raw materials Percentage by weight Sodium citrate 46,00 Sodium carbonate 22,92 Sodium chloride 1,37 Sodium percarbonate 19,18 Non-ionic surfactant 2,50 Ionic surfactant 3,13 Polyethylene glycol 4,50 Glycerin 0,30 Dye 0,10 TOTAL 100,00 Table 3: Composition of layer 2 Raw materials Percentage by weight Sodium citrate 46,00 Sodium carbonate 22,92 Sodium chloride 1,47 Sodium percarbonate 19,18 Non-ionic surfactant 2,50 Ionic surfactant 3,13 Polyethylene glycol 4,50 Glycerin 0,30 TOTAL 100,00 Table 4: Composition of layer 3 Raw materials Percentage by weight Sodium citrate 40,90 Sodium carbonate 34,43 Sodium chloride 2,54 Non-ionic surfactant 2,30 Ionic surfactant 2,50 Catalyst 1,60 Amylase 3,65 Protease 7,00 Polyethylene glycol 4,50 Glycerin 0,30 Dye 0,10 Scent 0,18 TOTAL 100,00

[0091] The results obtained are presented in Tables 5 and 6.

[0092] Surprisingly, it is observed that the combination of starch and proteins allows to obtain a homogeneous and solid coating after drying, allowing good protection of the tablet, even with low doses of protein. 3.2.2 Laundry care tablet (fabric softener)

[0093] To test the characteristics of the coated tablets according to the invention, coating tests according to the method described above were carried out in the laboratory on tablets of mass 12 g, rectangular shape and dimensions 36 mm (length) x 26 mm (width) x 12 mm (thickness), for use in washing machines, manufactured using a rotary press. The body of the tablets in these tests was of the same composition.

[0094] The results obtained are presented in Table 7. 3.2.3 Laundry detergent tablet

[0095] To test the characteristics of the coated tablets according to the invention, coating tests according to the method described above were carried out in the laboratory on tablets of mass 20 g, rectangular shape and dimensions 36 mm (length) x 26 mm (width) x 12 mm (thickness), for use in washing machines, manufactured using a rotary press. The body of the tablets in these tests was of the same composition.

[0096] The results obtained are presented in Table 8. 3.2.4 Tablet for charging

[0097] To test the characteristics of the coated tablets according to the invention, coating tests according to the method described above were carried out in the laboratory on tablets of mass 5 g, rectangular shape and dimensions 36 mm (length) x 26 mm (width) x 12 mm (thickness), manufactured using a rotary press. The body of the tablets in these tests was of the same composition.

[0098] The results obtained are presented in Table 9.

Claims

1. A coated tablet for household and fabric care comprising a body formed from compacted powder, said body being coated with a water-soluble covering comprising: a) a biosourced film-forming agent composed of the mixture of a polysaccharide, preferably a starch, and at least one protein, said protein being chosen from animal proteins, plant proteins and the mixtures thereof, the proportion by mass of proteins in said film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%; b) optionally a humectant; c) water; wherein the ratio by mass (biosourced film-forming agent / humectant) is between 1 and 30, ideally between 2 and 20 when the humectant is present.

2. The coated tablet according to claim 1, wherein the protein is chosen from plant proteins.

3. The coated tablet according to claim 2, wherein the plant protein is chosen from albumins, globulins, prolamins, glutelins and the mixtures thereof, preferably gluten.

4. The coated tablet according to claim 1 or 2, wherein the biosourced film-forming agent consists of the mixture of a starch and at least one plant protein chosen from albumins, globulins, prolamins, glutelins and the mixtures thereof, preferably gluten.

5. The tablet according to any one of claims 1 to 4, wherein the proportion by mass of proteins in said film-forming agent varies from 2% to 20%.

6. The tablet according to any one of claims 1 to 5, chosen from laundry machine tablets, dishwasher tablets, softening tablets or refill tablets.

7. A method for producing a coated tablet for household and fabric care comprising a body coated with a water-soluble covering, said method comprising the following steps: (1) providing a body formed from compacted powder; (2) spraying the surface of the body with a solution comprising: a) from 2% by mass to 80% by mass of a biosourced film-forming agent composed of the mixture of a polysaccharide, preferably a starch, and at least one protein, relative to the total mass of the solution, said protein being chosen from animal proteins, plant proteins and the mixtures thereof, the proportion by mass of proteins in said biosourced film-forming agent being greater than or equal to 1% and less than 50%, preferably ranging from 1% to 30%; b) at least 20% by mass of water relative to the total mass of the solution; and c) optionally, a humectant; the ratio by mass (biosourced film-forming agent / humectant) in said solution being between 1 and 30 when the humectant is present.

8. The method according to claim 7, wherein the protein is chosen from plant proteins.

9. The method according to claim 8, wherein the plant protein is chosen from albumins, globulins, prolamins, glutelins and the mixtures thereof, preferably gluten.

10. The method according to claim 7 or 8, wherein the biosourced film-forming agent is composed of the mixture of a starch and at least one plant protein chosen from albumins, globulins, prolamins, glutelins and the mixtures thereof, preferably gluten.

11. The method according to any one of claims 7 to 10, further comprising a drying step.

12. The method according to any one of claims 7 to 11, wherein the total quantity of sprayed solution varies from 25 g / m2 to 1000 g / m2.

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