Detergent tablets

Abstract

The invention relates to a detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl pyrrolidone from 4 to 20 percent by weight and surfactant. The invention also relates to a method of producing a liquid wash liquor. The invention also relates to the use of a detergent tablet to form a wash liquor.

Description

Field of the Invention

[0001] The field of the invention concerns detergent tablets with good structural rigidity that dissolve rapidly in water to produce a wash liquor.Background of the Invention

[0002] Detergent tablets are a known means of allowing an end user to form a ready to use liquid wash liquor, simply by the addition of a water to the detergent tablet (and optionally by agitating the mixture of water and the detergent tablet). They provide a convenient means of reducing storage space (during processing, distribution and at the point of sale) and allowing ingredients with a limited shelf life in liquid form to be incorporated into the solid and only converted into a wash liquor at the point of use.

[0003] One such use is in the formation of a multi-purpose spray cleaner. Such a product can be used to clean a variety of surfaces, for example a table, cooker or a tiled surface. In such an instance the tablet can be added directly to an empty bottle, mixed with water and then released from the bottle, for example via a trigger spray. Such bottles can be reused multiple times. Such a use is particularly common in industrial cleaning (e.g. hotel or restaurant kitchen cleaning), whereby large surface areas need to be cleaned relatively quickly, and so the ability to simply reuse the bottle and quickly refill it using a source of water and another detergent tablet is extremely useful. In this way employees working in the industrial cleaning sector are saved significant time and effort over the course of a shift, as effort is saved in having to dispose of and seek a fresh bottle multiple times.

[0004] Another example use is in the formation of a floor cleaning wash liquor. In such an instance the tablet is typically added to a bucket of water and allowed to dissolve. The wash liquor is then applied directly to the floor, typically via a mop or sponge. Cleaning a large area often results in the end user needing to fill the bucket multiple times. This is made easier through the use of detergent tablets. As these are relatively portable the end user can carry multiple with them as they clean, this is easier than carrying out a concentrated bottle of liquid detergent ingredients which can be quite heavy.

[0005] A common problem with known detergent tablets is that the dissolution time taken in tap water is too long, meaning that the end user has to wait a long time before they can use the cleaning solution or worse still they might begin using it before tablet dissolution is complete, leading to residues on the substrate, insufficient performance etc. This is an important consideration in a high-volume usage environment, for example industrial cleaning.

[0006] Despite the prior art there exists the need for detergent tablets which dissolve rapidly in water to produce an adequate wash liquor.Summary of the Invention

[0007] In a first aspect there is provided a detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl polypyrrolidone from 4 to 20 percent by weight and surfactant.

[0008] The inventors have surprisingly found that by forming a detergent tablet comprising glucose monohydrate and polyvinyl polypyrrolidone (PVPP) at particular weight inclusion levels structural integrity can be maintained whilst delivering rapid dissolution.

[0009] In a second aspect there is provided a method for forming a wash liquor by combining water and the tablet of the first aspect of the invention in a container, and optionally agitating the mixture.

[0010] In a third aspect there is provided the use of the detergent tablet of the first aspect to form a wash liquor.

[0011] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from reading of the following detailed description. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.Detailed Description of the Invention Detergent tablet

[0012] By "detergent tablet" as used herein, is meant a solid tablet suitable for dissolution in water to create a liquid wash liquor comprising detersive ingredients.

[0013] By "disintegrant" as used herein, is meant an ingredient present in a tablet to accelerate dissolution of the tablet in water. In contact with water such ingredients cause the tablet to break or disintegrate into smaller fragments thereby accelerating the dissolution. According to the present invention the disintegrant comprises a combination of glucose monohydrate and polyvinyl polypyrrolidone.

[0014] By "polyvinyl polypyrrolidone" as used herein, is meant highly crosslinked polyvinyl pyrrolidone. Polyvinyl polypyrrolidone is water-insoluble, but it is water swellable.

[0015] In a first aspect there is provided a detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl pyrrolidone from 4 to 20 percent by weight and surfactant.

[0016] The tablet according to the present invention preferably comprises polyvinyl polypyrrolidone from 5 to 15 percent by weight and most preferably from 5 to 10 by weight of the tablet.

[0017] The tablet according to the present invention preferably comprises glucose monohydrate from 30 to 70 percent by weight, more preferably from 35 to 65 percent by weight and most preferably from 35 to 60wt percent by weight of the tablet.

[0018] Preferably the weight ratio of glucose monohydrate to polyvinyl polypyrrolidone is from 9:1 to 1:3, more preferably from 8:1 to 1:3, more preferably is from 8:1 to 1:2 and most preferably is from 8:1 to 1:1Disintegrant

[0019] The detergent tablet composition comprises a soluble disintegrant and an insoluble disintegrant. The soluble disintegrant comprises glucose monohydrate. The insoluble disintegrant comprises polyvinyl polypyrrolidone.

[0020] EMDEX ®< - is a commercially available material (available from JRS Pharma). It is a combination of glucose monohydrate and various starch-derived polysaccharides at a 19:1 weight ratio. It provides a suitable soluble disintegrant for use in the invention.Surfactant

[0021] Tablets according to the invention comprise a surfactant. Preferably the tablets comprise from 10 to 50 percent by weight surfactant, more preferably from 12 to 40 percent by weight surfactant and most preferably from 14 to 30 percent by weight surfactant by weight of the total tablet.

[0022] Preferably the surfactant comprises anionic surfactant. If present the anionic surfactant is present at from 1 to 100 percent by weight of the total surfactant content.

[0023] Preferably the surfactant comprises nonionic surfactant. If present the nonionic surfactant is present at from 1 to 100 percent by weight of the total surfactant content.

[0024] Most preferably the surfactant comprises both anionic and non-ionic surfactant.

[0025] Preferably the anionic surfactant is selected from alkyl sulphate, alkyl ether sulphate, linear alkyl benzene sulphonate (LAS), taurate and combinations thereof. Most preferably the anionic surfactant selected from linear alkyl benzene sulphonate and a taurate and combinations thereof. Preferably the taurate surfactant is sodium methyl cocoyl taurate.

[0026] Commercial LAS is a mixture of closely related isomers and homologues alkyl chain homologues, each containing an aromatic ring sulfonated at the "para" position and attached to a linear alkyl chain at any position except the terminal carbons. The linear alkyl chain typically has a chain length of from 11 to 15 carbon atoms, with the predominant materials having a chain length of about C12. Each alkyl chain homologue consists of a mixture of all the possible sulpho-phenyl isomers except for the 1-phenyl isomer. LAS is normally formulated into compositions in acid (i.e., HLAS) form and then at least partially neutralized in-situ. The counterion for anionic surfactants is generally an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine (MEA), diethanolamine (DEA) or triethanolamine (TEA), monoisopropanolamine (MIPA). Mixtures of such counterions may also be employed. Sodium and potassium are preferred. An example of a suitable commercial grade of LAS is Ufaryl DL 8, available from Unger Fabrikker AS.

[0027] If an alkyl ether sulphate is selected then preferably it contains from one to ten ethylene oxide or propylene oxide units per molecule, and more preferably it contains one to three ethylene oxide units per molecule.

[0028] If an alkyl sulphate is selected then preferably it comprises an alkyl chain length of from 10 to 18, more preferably it comprises primary alkyl sulphate (PAS) with an average alkyl chain length of about 12.

[0029] Further anionic surfactants suitable for the present invention include salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term "alkyl" being used to include the alkyl portion of higher acyl radicals. Examples of such materials include alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof. The alkyl radicals preferably contain from 10 to 18 carbon atoms and may be unsaturated.

[0030] Preferably the amount of the anionic surfactant is in the range up to 100% by weight of the total amount of the surfactant. More preferably, the amount of anionic surfactant is in the range 10 to 90%, even more preferably 20 to 80%, most preferably 30 to 70% by weight of the total amount of surfactant.

[0031] The tablet according to the present invention may comprise a non-ionic surfactant.

[0032] Suitable non-ionic surfactants include water soluble aliphatic ethoxylated non-ionic surfactants including the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. This includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 30 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 10 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol.

[0033] Suitable non-ionic surfactants also include solid non-ionic surfactants with about 25 to 50 moles of EO, more preferably 25 to 40 moles and most preferably 30 to 40 moles of EO. Such non-ionic surfactants typically have a carbon chain length of C16-18.

[0034] An example of a suitable commercially available non-ionic is Genapol ®< T250 (available from Clariant).

[0035] Another group of suitable non-ionic surfactants are alkyl polyglycosides (APG) which are sugar derivatives of fatty alcohol. Example of such surfactants are decyl glucoside, lauryl glucoside, myristyl glucoside.

[0036] The tablet may further comprise a cationic or an amphoteric surfactant in addition to the anionic and the non-ionic surfactant.

[0037] Suitable cationic surfactants are quaternary ammonium salts. According to the present invention quaternary ammonium salts are characterised in that the ammonium salt has the general formula: R1 R2R3R4N+X- wherein R1 is a C12 to C18 alkyl group, each of R2, R3 and R4 independently is a C1 to C3 alkyl group and X is an inorganic anion. R1 is preferably a C14 to C16 straight chain alkyl group, more preferably C16. R2, R3 and R4 are preferably methyl groups. The inorganic anion (X-) is preferably chosen from halide, sulphate, bisulphate or hydroxide.

[0038] For the purposes of this invention, a quaternary ammonium hydroxide is considered to be a quaternary ammonium salt. More preferably the anion is a halide ion or sulphate, most preferably a chloride or sulphate. Cetyl-trimethylammonium chloride is a specific example of a suitable compound and commercially abundantly available.

[0039] Another type of quaternary ammonium cationic surfactant is the class of benzalkonium halides, also known as alkyldimethylbenzylammonium halides. The most common type being benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride (or ADBAC). Suitable amphoteric surfactants include derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3-(N-N-dimethyl-N-hexadecylammonium) propane-1 -sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-1 -sulphonate betaine and 3- (cetylmethylphosphonium) ethane sulphonate betaine.

[0040] Examples of amphoteric surfactants suitable for the present invention include cocoamidopropyl betaine (CAPB), cocoamidopropyl amine oxide (CAPAO), cocodiethanol amide (CDEA) and cocomonoethanol amide (CMEA).Effervescent

[0041] Preferably the composition comprises an effervescent. By "effervescent" as used herein, is meant an ingredient that expediates the dissolution of the tablet in water, by releasing gas when it is brought into contact with water.

[0042] Suitable effervescents include organic acids such as citric acid, tartaric acid, fumaric acid, malic acid, adipic acid, succinic acid, and a carbonate salt. Preferred carbonate salts include sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, calcium carbonate, calcium bicarbonate and magnesium carbonate as well as mixtures thereof. A particularly preferred effervescent is citric acid.

[0043] The level of effervescent is preferably from 1 to 30wt% of the tablet, more preferably from 2 to 27wt% of the composition, more preferably from 3 to 24wt% and most preferably from 6 to 21wt% of the composition.Filler

[0044] Typically detergent tablets comprise one or more filler ingredients. Fillers suitable for use in the tablet include sodium carbonate, calcium carbonate, zeolite, clays such as bentonite, dolomite and combinations thereof. A preferred filler is sodium carbonate.Hydrotrope

[0045] The tablet may comprise a hydrotrope. Hydrotropes are a class of low molecular weight compounds having a hydrophilic and hydrophobic part similar to surfactants. However, the hydrophobic part is much smaller compared to surfactants. Thus, they may not lead to spontaneous self-aggregation or micellar solubilization. It is also observed that the hydrotrope does not have a critical micellar concentration (CMC) or a critical vesicle concentration (CVC) like surfactants. It may possible that hydrotrope aggregates in a stepwise self-aggregation process, gradually increasing aggregation size. Preferably the hydrotrope comprises an alkyl aryl sulphonate having C1 to C5 alkyl chain.

[0046] The tablet preferably comprises 0.1 to 10% by weight of the hydrotrope. More preferably the tablet comprises 0.2 to 9% by weight, even more preferably 0.3 to 8% by weight and most preferably 0.3 to 7% by weight of the hydrotrope.

[0047] The hydrotrope may be selected from sodium xylene sulphonate, sodium toluene sulphonate, sodium cumene sulphonate, potassium xylene sulphonate, potassium toluene sulphonate, potassium cumene sulphonate and combinations thereof. Most preferred hydrotropes are sodium cumene sulphonate and / or sodium xylene sulphonate.Dye

[0048] The composition may comprise one or more dyes to provide colour to the tablet.Preservative

[0049] Optionally the detergent tablet may comprise a material capable of preserving the resulting liquid wash liquor from bacterial, fungal and / or mould spoilage. Suitable such materials include sodium benzoate, potassium sorbate, lactic acid, isothiazolinones and the like. A particularly preferred material is sodium benzoate.Process of making a tablet

[0050] A homogenised dry powder is first prepared by mixing the ingredients in specified ratio. Subsequently, the powder is filled in a die-block and compressed to form the tablet. A rotary press or a hydraulic press maybe employed to compress the powder to tablet.

[0051] Preferably the pressure applied during the compression is in the range 1 to 100 kg-f / cm 2< , more preferably 2.5 to 75 kg-f / cm 2< , even more preferably 5 to 50 kg-f / cm 2< , and most preferably 7.5 to 30 kg-f / cm 2< .Mass of tablet

[0052] Tablets according to the invention can be manufactured in a variety of sizes. The preferred mass of a single tablet is from 2 to 10g, more preferably from 3 to 8g and most preferably from 4 to 6g. Such a size allows for a sufficient mass of surfactant to be included such that the resulting liquid wash liquor has sufficient surfactant to function as a plethora of applications, for example a floor cleaner or multi-surface spray, in particular such a floor cleaner or multi-surface spray suitable for use in an industrial cleaning context.Compression strength

[0053] Preferably the tablet has a compression strength of from 50 to 300N, more preferably 60 to 270N, more preferably from 70 to 250N and most preferably from 80 to 240N.Method of producing a liquid wash liquor Application

[0054] The tablet according to the present invention may be formulated for cleaning surfaces, in particular hard surfaces. Hard surface cleaning compositions are generally used for cleaning surfaces such as: kitchen utensils, dishes, kitchen platforms, tabletops, worktops, floors etc. One of such examples is a tablet for dishwashing. Another of such examples is a tablet for floor cleaning.

[0055] It may also be possible to formulate the tablet for providing a multi-use liquid detergent. The consumer may prepare a liquid detergent by dissolving the tablet in a secondary container and storing it for multiple uses.

[0056] In a second aspect there is provided a method for forming a wash liquor by combing the tablet of the first aspect of the invention with water in a container, and optionally agitating the mixture. Preferably the ratio of the tablet to water is in the range of 1:10 to 1:10,000 by weight or by volume. More preferably the ratio of the tablet to water is in the range 1:15 to 1:5,000 by weight or by volume, even more preferably 1:20 to 1:1,000 and most preferably 1:25 to 1:500 by weight or by volume.Use of a detergent tablet

[0057] Use of the detergent tablet disclosed in the first aspect of the invention is herein disclosed for the creation of a liquid wash liquor. A wash liquor is created when the detergent tablet is sufficiently dissolved such that the cleaning ingredients originally contained in the tablet are dissolved into the water. The liquor is then ready for use by an end user. Preferably such a wash liquor is formed in 5 minutes or less.Methods of testing

[0058] Several properties of the tablets produced were assessed by dissolving the tablets in water at 25°C.Disintegration time

[0059] This is considered the point at which at least 80% of the tablet was observed to have broken away from the original structure.Dissolution time

[0060] This is considered to be the point at which all of the soluble material has dissolved, for the compositions in table 1 sodium benzoate is the last such ingredient to dissolve.Tablet strength

[0061] Tablet strength was measured on a Texture Analyser supplied by Stable Micro Systems, UK. The tablets were assessed using ASTM D4179-11. The tablets were placed with their circular face aligned with the slot holder of the machine. The machine was then calibrated to the height of the tablet through the built-in automated height calibration process. The test was then executed and the machine applied the threshold pressure on the tablet up to the point of fracture. At this point the test was stopped by the machine. The force required to break the tablet was displayed on the machine; this was recorded as the tablet strength.Tablet strength drop test (number required to fracture):

[0062] Tablets were dropped individually from a height of 1.8m. The tablets were dropped repeatedly in the same manner until the tablet broke into two or more parts.Visual observation

[0063] Visual observations were recorded at the end of the dissolution trial.Examples

[0064] Table 1: Test tablets were produced using the following ingredients:IngredientComparative A (wt%)Comparative B (wt%)Example 1 (wt%)Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.134.134.13Sodium methyl cocoyl taurate (Aquanate Cot 75)9.959.959.95p-sodium cumene sulphonate (Eltesol SC93)2.932.932.93Citric Acid Anhydrous (fine grade)202020Glucose monohydrate (from EMDEX ®< )45.230.0038.10Oligosaccharides (from EMDEX ®< )2.380.002.01D62221F BLUE LF (Direct Blue 199)0.0330.0330.033Sodium Benzoate6.06.06.0Fragrance8.338.338.33PVPP0.0047.587.50Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)1.031.031.03

[0065] Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0066] In each case 5 cylindrical-shaped tablets of 6g with a diameter of 20mm were produced (height about 22-24mm).

[0067] The tablets were produced by adding the relevant ingredients one at a time into a suitable airtight container and the container was sealed (with sufficient headspace to allow mixing). The composition was then shaken vigorously for 2 minutes to ensure good mixing of the ingredients. The mixture was then filled into a die-block and compressed to form a tablet.Results

[0068] The following results are the average results across 5 tablets for the compositions described in table 1. Table 2 - performance data (for tablets compressed at 98N / cm 2< )TestComparative AComparative BExample 1Disintegration time (min : secs)15:00 (stdev = 0:38)1:02 (stdev = 0:10)1:48 (stdev = 0:17)Dissolution time** (min : secs)20:36 (stdev = 0:48)5:48 (stdev = 0:44)8:12 (stdev = 0:44)Tablet strength (kN)189 (stdev = 3.4)67 (stdev = 5.8)161 (stdev = 3.2)Number of drops to fracture613Visual observation post dilutionTransparentOpaqueSemi-transparent** = the point at which the sodium benzoate was considered dissolved Table 3 - performance data (for tablets compressed at 147N / cm 2< ) TestComparative AComparative BExample 1Disintegration time (min : secs)25:12 (stdev = 1:20)1:20 (stdev = 0:38)2:39 (stdev = 0:14)Dissolution time**30:48 (stdev = 1:43)6:36 (stdev = 0:29)10:48 (stdev = 0:44)Tablet strength (kN)232 (stdev = 3.7)121 (stdev = 3.7)230 (stdev = 11.8)Number of drops to fracture915Visual observation post dilutionTransparentOpaqueSemi-transparent ** = the point at which the sodium benzoate was considered dissolved Second study

[0069] Table 4: Test tablets were produced using the following ingredients:IngredientComparative C (wt%)Comparative D (wt%)Example 2 (wt%)Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.504.004.50Citric Acid Anhydrous (fine grade)8.008.008.00Glucose monohydrate (from EMDEX ®< )59.380.0052.26Oligosaccharides (from EMDEX ®< )3.130.002.75Dye (tatrazine)0.200.200.20Sodium Carbonate6.506.506.50Fragrance3.703.703.70Polyvinyl polypyrrolidone0.0064.637.50Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)13.5012.0013.50

[0070] Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0071] In all cases tablets of 6g were produced that were cylindrical in shape and had a diameter of 20mm.Results

[0072] The following results are for the compositions described in table 4. The results are the average of 5 tablets in each case. Table 5 - performance data (for tablets compressed at 147N / cm 2< )TestComparative CComparative DExample 2Disintegration time (min : secs)35:00 (stdev = 5:00)1:30 (stdev = 0)1:05 (stdev = 0:06)Tablet strength (kN)264 (stdev = 10.7)27 (stdev = 7.0)86 (stdev = 13.8)CommentDisintegration time too high for intended end useToo fragile to process Table 6 - performance data (for tablets compressed at 196N / cm 2< ) TestComparative CComparative DExample 2Disintegration time (min : secs)44:00 (stdev = 4:10)2:14 (stdev = 0:12)2:00 (stdev = 0:12)Tablet strength (kN)288 (stdev = 7.5)62 (stdev = 10.5)130 (stdev = 11.7)CommentDisintegration time too high for intended end useToo fragile to process Discussion of results

[0073] As can be seen in the results in tables 2, 3, 5 and 6 the inclusion of a low amount of PVPP results in a disintegration time and dissolution time that is comparable to a very high level of PVPP, whereas the tablet strength is comparable to a composition with a very high level of EMDEX. These trends are further exemplified in the figures in the application.

Examples

examples

Examples

[0064]

Table 1: Test tablets were produced using the following ingredients:

IngredientComparative A (wt%)Comparative B (wt%)Example 1 (wt%)

Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.134.134.13

Sodium methyl cocoyl taurate (Aquanate Cot 75)9.959.959.95

p-sodium cumene sulphonate (Eltesol SC93)2.932.932.93

Citric Acid Anhydrous (fine grade)202020

Glucose monohydrate (from EMDEX ®45.230.0038.10

Oligosaccharides (from EMDEX ®2.380.002.01

D62221F BLUE LF (Direct Blue 199)0.0330.0330.033

Sodium Benzoate6.06.06.0

Fragrance8.338.338.33

PVPP0.0047.587.50

Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)1.031.031.03

[0065]Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0066]In each case 5 cylindrical-shaped tablets of 6g with a diameter of 20mm were produced (height about 22-24mm).

[0067]The tablets were produced by adding the relevant ingredients one at a time into a suitable airtight c...

Field of the Invention

[0001] The field of the invention concerns detergent tablets with good structural rigidity that dissolve rapidly in water to produce a wash liquor.Background of the Invention

[0002] Detergent tablets are a known means of allowing an end user to form a ready to use liquid wash liquor, simply by the addition of a water to the detergent tablet (and optionally by agitating the mixture of water and the detergent tablet). They provide a convenient means of reducing storage space (during processing, distribution and at the point of sale) and allowing ingredients with a limited shelf life in liquid form to be incorporated into the solid and only converted into a wash liquor at the point of use.

[0003] One such use is in the formation of a multi-purpose spray cleaner. Such a product can be used to clean a variety of surfaces, for example a table, cooker or a tiled surface. In such an instance the tablet can be added directly to an empty bottle, mixed with water and then released from the bottle, for example via a trigger spray. Such bottles can be reused multiple times. Such a use is particularly common in industrial cleaning (e.g. hotel or restaurant kitchen cleaning), whereby large surface areas need to be cleaned relatively quickly, and so the ability to simply reuse the bottle and quickly refill it using a source of water and another detergent tablet is extremely useful. In this way employees working in the industrial cleaning sector are saved significant time and effort over the course of a shift, as effort is saved in having to dispose of and seek a fresh bottle multiple times.

[0004] Another example use is in the formation of a floor cleaning wash liquor. In such an instance the tablet is typically added to a bucket of water and allowed to dissolve. The wash liquor is then applied directly to the floor, typically via a mop or sponge. Cleaning a large area often results in the end user needing to fill the bucket multiple times. This is made easier through the use of detergent tablets. As these are relatively portable the end user can carry multiple with them as they clean, this is easier than carrying out a concentrated bottle of liquid detergent ingredients which can be quite heavy.

[0005] A common problem with known detergent tablets is that the dissolution time taken in tap water is too long, meaning that the end user has to wait a long time before they can use the cleaning solution or worse still they might begin using it before tablet dissolution is complete, leading to residues on the substrate, insufficient performance etc. This is an important consideration in a high-volume usage environment, for example industrial cleaning.

[0006] Despite the prior art there exists the need for detergent tablets which dissolve rapidly in water to produce an adequate wash liquor.Summary of the Invention

[0007] In a first aspect there is provided a detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl polypyrrolidone from 4 to 20 percent by weight and surfactant.

[0008] The inventors have surprisingly found that by forming a detergent tablet comprising glucose monohydrate and polyvinyl polypyrrolidone (PVPP) at particular weight inclusion levels structural integrity can be maintained whilst delivering rapid dissolution.

[0009] In a second aspect there is provided a method for forming a wash liquor by combining water and the tablet of the first aspect of the invention in a container, and optionally agitating the mixture.

[0010] In a third aspect there is provided the use of the detergent tablet of the first aspect to form a wash liquor.

[0011] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from reading of the following detailed description. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.Detailed Description of the Invention Detergent tablet

[0012] By "detergent tablet" as used herein, is meant a solid tablet suitable for dissolution in water to create a liquid wash liquor comprising detersive ingredients.

[0013] By "disintegrant" as used herein, is meant an ingredient present in a tablet to accelerate dissolution of the tablet in water. In contact with water such ingredients cause the tablet to break or disintegrate into smaller fragments thereby accelerating the dissolution. According to the present invention the disintegrant comprises a combination of glucose monohydrate and polyvinyl polypyrrolidone.

[0014] By "polyvinyl polypyrrolidone" as used herein, is meant highly crosslinked polyvinyl pyrrolidone. Polyvinyl polypyrrolidone is water-insoluble, but it is water swellable.

[0015] In a first aspect there is provided a detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl pyrrolidone from 4 to 20 percent by weight and surfactant.

[0016] The tablet according to the present invention preferably comprises polyvinyl polypyrrolidone from 5 to 15 percent by weight and most preferably from 5 to 10 by weight of the tablet.

[0017] The tablet according to the present invention preferably comprises glucose monohydrate from 30 to 70 percent by weight, more preferably from 35 to 65 percent by weight and most preferably from 35 to 60wt percent by weight of the tablet.

[0018] Preferably the weight ratio of glucose monohydrate to polyvinyl polypyrrolidone is from 9:1 to 1:3, more preferably from 8:1 to 1:3, more preferably is from 8:1 to 1:2 and most preferably is from 8:1 to 1:1Disintegrant

[0019] The detergent tablet composition comprises a soluble disintegrant and an insoluble disintegrant. The soluble disintegrant comprises glucose monohydrate. The insoluble disintegrant comprises polyvinyl polypyrrolidone.

[0020] EMDEX ®< - is a commercially available material (available from JRS Pharma). It is a combination of glucose monohydrate and various starch-derived polysaccharides at a 19:1 weight ratio. It provides a suitable soluble disintegrant for use in the invention.Surfactant

[0021] Tablets according to the invention comprise a surfactant. Preferably the tablets comprise from 10 to 50 percent by weight surfactant, more preferably from 12 to 40 percent by weight surfactant and most preferably from 14 to 30 percent by weight surfactant by weight of the total tablet.

[0022] Preferably the surfactant comprises anionic surfactant. If present the anionic surfactant is present at from 1 to 100 percent by weight of the total surfactant content.

[0023] Preferably the surfactant comprises nonionic surfactant. If present the nonionic surfactant is present at from 1 to 100 percent by weight of the total surfactant content.

[0024] Most preferably the surfactant comprises both anionic and non-ionic surfactant.

[0025] Preferably the anionic surfactant is selected from alkyl sulphate, alkyl ether sulphate, linear alkyl benzene sulphonate (LAS), taurate and combinations thereof. Most preferably the anionic surfactant selected from linear alkyl benzene sulphonate and a taurate and combinations thereof. Preferably the taurate surfactant is sodium methyl cocoyl taurate.

[0026] Commercial LAS is a mixture of closely related isomers and homologues alkyl chain homologues, each containing an aromatic ring sulfonated at the "para" position and attached to a linear alkyl chain at any position except the terminal carbons. The linear alkyl chain typically has a chain length of from 11 to 15 carbon atoms, with the predominant materials having a chain length of about C12. Each alkyl chain homologue consists of a mixture of all the possible sulpho-phenyl isomers except for the 1-phenyl isomer. LAS is normally formulated into compositions in acid (i.e., HLAS) form and then at least partially neutralized in-situ. The counterion for anionic surfactants is generally an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine (MEA), diethanolamine (DEA) or triethanolamine (TEA), monoisopropanolamine (MIPA). Mixtures of such counterions may also be employed. Sodium and potassium are preferred. An example of a suitable commercial grade of LAS is Ufaryl DL 8, available from Unger Fabrikker AS.

[0027] If an alkyl ether sulphate is selected then preferably it contains from one to ten ethylene oxide or propylene oxide units per molecule, and more preferably it contains one to three ethylene oxide units per molecule.

[0028] If an alkyl sulphate is selected then preferably it comprises an alkyl chain length of from 10 to 18, more preferably it comprises primary alkyl sulphate (PAS) with an average alkyl chain length of about 12.

[0029] Further anionic surfactants suitable for the present invention include salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term "alkyl" being used to include the alkyl portion of higher acyl radicals. Examples of such materials include alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof. The alkyl radicals preferably contain from 10 to 18 carbon atoms and may be unsaturated.

[0030] Preferably the amount of the anionic surfactant is in the range up to 100% by weight of the total amount of the surfactant. More preferably, the amount of anionic surfactant is in the range 10 to 90%, even more preferably 20 to 80%, most preferably 30 to 70% by weight of the total amount of surfactant.

[0031] The tablet according to the present invention may comprise a non-ionic surfactant.

[0032] Suitable non-ionic surfactants include water soluble aliphatic ethoxylated non-ionic surfactants including the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. This includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 30 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 10 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol.

[0033] Suitable non-ionic surfactants also include solid non-ionic surfactants with about 25 to 50 moles of EO, more preferably 25 to 40 moles and most preferably 30 to 40 moles of EO. Such non-ionic surfactants typically have a carbon chain length of C16-18.

[0034] An example of a suitable commercially available non-ionic is Genapol ®< T250 (available from Clariant).

[0035] Another group of suitable non-ionic surfactants are alkyl polyglycosides (APG) which are sugar derivatives of fatty alcohol. Example of such surfactants are decyl glucoside, lauryl glucoside, myristyl glucoside.

[0036] The tablet may further comprise a cationic or an amphoteric surfactant in addition to the anionic and the non-ionic surfactant.

[0037] Suitable cationic surfactants are quaternary ammonium salts. According to the present invention quaternary ammonium salts are characterised in that the ammonium salt has the general formula: R1 R2R3R4N+X- wherein R1 is a C12 to C18 alkyl group, each of R2, R3 and R4 independently is a C1 to C3 alkyl group and X is an inorganic anion. R1 is preferably a C14 to C16 straight chain alkyl group, more preferably C16. R2, R3 and R4 are preferably methyl groups. The inorganic anion (X-) is preferably chosen from halide, sulphate, bisulphate or hydroxide.

[0038] For the purposes of this invention, a quaternary ammonium hydroxide is considered to be a quaternary ammonium salt. More preferably the anion is a halide ion or sulphate, most preferably a chloride or sulphate. Cetyl-trimethylammonium chloride is a specific example of a suitable compound and commercially abundantly available.

[0039] Another type of quaternary ammonium cationic surfactant is the class of benzalkonium halides, also known as alkyldimethylbenzylammonium halides. The most common type being benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride (or ADBAC). Suitable amphoteric surfactants include derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3-(N-N-dimethyl-N-hexadecylammonium) propane-1 -sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-1 -sulphonate betaine and 3- (cetylmethylphosphonium) ethane sulphonate betaine.

[0040] Examples of amphoteric surfactants suitable for the present invention include cocoamidopropyl betaine (CAPB), cocoamidopropyl amine oxide (CAPAO), cocodiethanol amide (CDEA) and cocomonoethanol amide (CMEA).Effervescent

[0041] Preferably the composition comprises an effervescent. By "effervescent" as used herein, is meant an ingredient that expediates the dissolution of the tablet in water, by releasing gas when it is brought into contact with water.

[0042] Suitable effervescents include organic acids such as citric acid, tartaric acid, fumaric acid, malic acid, adipic acid, succinic acid, and a carbonate salt. Preferred carbonate salts include sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, calcium carbonate, calcium bicarbonate and magnesium carbonate as well as mixtures thereof. A particularly preferred effervescent is citric acid.

[0043] The level of effervescent is preferably from 1 to 30wt% of the tablet, more preferably from 2 to 27wt% of the composition, more preferably from 3 to 24wt% and most preferably from 6 to 21wt% of the composition.Filler

[0044] Typically detergent tablets comprise one or more filler ingredients. Fillers suitable for use in the tablet include sodium carbonate, calcium carbonate, zeolite, clays such as bentonite, dolomite and combinations thereof. A preferred filler is sodium carbonate.Hydrotrope

[0045] The tablet may comprise a hydrotrope. Hydrotropes are a class of low molecular weight compounds having a hydrophilic and hydrophobic part similar to surfactants. However, the hydrophobic part is much smaller compared to surfactants. Thus, they may not lead to spontaneous self-aggregation or micellar solubilization. It is also observed that the hydrotrope does not have a critical micellar concentration (CMC) or a critical vesicle concentration (CVC) like surfactants. It may possible that hydrotrope aggregates in a stepwise self-aggregation process, gradually increasing aggregation size. Preferably the hydrotrope comprises an alkyl aryl sulphonate having C1 to C5 alkyl chain.

[0046] The tablet preferably comprises 0.1 to 10% by weight of the hydrotrope. More preferably the tablet comprises 0.2 to 9% by weight, even more preferably 0.3 to 8% by weight and most preferably 0.3 to 7% by weight of the hydrotrope.

[0047] The hydrotrope may be selected from sodium xylene sulphonate, sodium toluene sulphonate, sodium cumene sulphonate, potassium xylene sulphonate, potassium toluene sulphonate, potassium cumene sulphonate and combinations thereof. Most preferred hydrotropes are sodium cumene sulphonate and / or sodium xylene sulphonate.Dye

[0048] The composition may comprise one or more dyes to provide colour to the tablet.Preservative

[0049] Optionally the detergent tablet may comprise a material capable of preserving the resulting liquid wash liquor from bacterial, fungal and / or mould spoilage. Suitable such materials include sodium benzoate, potassium sorbate, lactic acid, isothiazolinones and the like. A particularly preferred material is sodium benzoate.Process of making a tablet

[0050] A homogenised dry powder is first prepared by mixing the ingredients in specified ratio. Subsequently, the powder is filled in a die-block and compressed to form the tablet. A rotary press or a hydraulic press maybe employed to compress the powder to tablet.

[0051] Preferably the pressure applied during the compression is in the range 1 to 100 kg-f / cm 2< , more preferably 2.5 to 75 kg-f / cm 2< , even more preferably 5 to 50 kg-f / cm 2< , and most preferably 7.5 to 30 kg-f / cm 2< .Mass of tablet

[0052] Tablets according to the invention can be manufactured in a variety of sizes. The preferred mass of a single tablet is from 2 to 10g, more preferably from 3 to 8g and most preferably from 4 to 6g. Such a size allows for a sufficient mass of surfactant to be included such that the resulting liquid wash liquor has sufficient surfactant to function as a plethora of applications, for example a floor cleaner or multi-surface spray, in particular such a floor cleaner or multi-surface spray suitable for use in an industrial cleaning context.Compression strength

[0053] Preferably the tablet has a compression strength of from 50 to 300N, more preferably 60 to 270N, more preferably from 70 to 250N and most preferably from 80 to 240N.Method of producing a liquid wash liquor Application

[0054] The tablet according to the present invention may be formulated for cleaning surfaces, in particular hard surfaces. Hard surface cleaning compositions are generally used for cleaning surfaces such as: kitchen utensils, dishes, kitchen platforms, tabletops, worktops, floors etc. One of such examples is a tablet for dishwashing. Another of such examples is a tablet for floor cleaning.

[0055] It may also be possible to formulate the tablet for providing a multi-use liquid detergent. The consumer may prepare a liquid detergent by dissolving the tablet in a secondary container and storing it for multiple uses.

[0056] In a second aspect there is provided a method for forming a wash liquor by combing the tablet of the first aspect of the invention with water in a container, and optionally agitating the mixture. Preferably the ratio of the tablet to water is in the range of 1:10 to 1:10,000 by weight or by volume. More preferably the ratio of the tablet to water is in the range 1:15 to 1:5,000 by weight or by volume, even more preferably 1:20 to 1:1,000 and most preferably 1:25 to 1:500 by weight or by volume.Use of a detergent tablet

[0057] Use of the detergent tablet disclosed in the first aspect of the invention is herein disclosed for the creation of a liquid wash liquor. A wash liquor is created when the detergent tablet is sufficiently dissolved such that the cleaning ingredients originally contained in the tablet are dissolved into the water. The liquor is then ready for use by an end user. Preferably such a wash liquor is formed in 5 minutes or less.Methods of testing

[0058] Several properties of the tablets produced were assessed by dissolving the tablets in water at 25°C.Disintegration time

[0059] This is considered the point at which at least 80% of the tablet was observed to have broken away from the original structure.Dissolution time

[0060] This is considered to be the point at which all of the soluble material has dissolved, for the compositions in table 1 sodium benzoate is the last such ingredient to dissolve.Tablet strength

[0061] Tablet strength was measured on a Texture Analyser supplied by Stable Micro Systems, UK. The tablets were assessed using ASTM D4179-11. The tablets were placed with their circular face aligned with the slot holder of the machine. The machine was then calibrated to the height of the tablet through the built-in automated height calibration process. The test was then executed and the machine applied the threshold pressure on the tablet up to the point of fracture. At this point the test was stopped by the machine. The force required to break the tablet was displayed on the machine; this was recorded as the tablet strength.Tablet strength drop test (number required to fracture):

[0062] Tablets were dropped individually from a height of 1.8m. The tablets were dropped repeatedly in the same manner until the tablet broke into two or more parts.Visual observation

[0063] Visual observations were recorded at the end of the dissolution trial.Examples

[0064] Table 1: Test tablets were produced using the following ingredients:IngredientComparative A (wt%)Comparative B (wt%)Example 1 (wt%)Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.134.134.13Sodium methyl cocoyl taurate (Aquanate Cot 75)9.959.959.95p-sodium cumene sulphonate (Eltesol SC93)2.932.932.93Citric Acid Anhydrous (fine grade)202020Glucose monohydrate (from EMDEX ®< )45.230.0038.10Oligosaccharides (from EMDEX ®< )2.380.002.01D62221F BLUE LF (Direct Blue 199)0.0330.0330.033Sodium Benzoate6.06.06.0Fragrance8.338.338.33PVPP0.0047.587.50Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)1.031.031.03

[0065] Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0066] In each case 5 cylindrical-shaped tablets of 6g with a diameter of 20mm were produced (height about 22-24mm).

[0067] The tablets were produced by adding the relevant ingredients one at a time into a suitable airtight container and the container was sealed (with sufficient headspace to allow mixing). The composition was then shaken vigorously for 2 minutes to ensure good mixing of the ingredients. The mixture was then filled into a die-block and compressed to form a tablet.Results

[0068] The following results are the average results across 5 tablets for the compositions described in table 1. Table 2 - performance data (for tablets compressed at 98N / cm 2< )TestComparative AComparative BExample 1Disintegration time (min : secs)15:00 (stdev = 0:38)1:02 (stdev = 0:10)1:48 (stdev = 0:17)Dissolution time** (min : secs)20:36 (stdev = 0:48)5:48 (stdev = 0:44)8:12 (stdev = 0:44)Tablet strength (kN)189 (stdev = 3.4)67 (stdev = 5.8)161 (stdev = 3.2)Number of drops to fracture613Visual observation post dilutionTransparentOpaqueSemi-transparent** = the point at which the sodium benzoate was considered dissolved Table 3 - performance data (for tablets compressed at 147N / cm 2< ) TestComparative AComparative BExample 1Disintegration time (min : secs)25:12 (stdev = 1:20)1:20 (stdev = 0:38)2:39 (stdev = 0:14)Dissolution time**30:48 (stdev = 1:43)6:36 (stdev = 0:29)10:48 (stdev = 0:44)Tablet strength (kN)232 (stdev = 3.7)121 (stdev = 3.7)230 (stdev = 11.8)Number of drops to fracture915Visual observation post dilutionTransparentOpaqueSemi-transparent ** = the point at which the sodium benzoate was considered dissolved Second study

[0069] Table 4: Test tablets were produced using the following ingredients:IngredientComparative C (wt%)Comparative D (wt%)Example 2 (wt%)Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.504.004.50Citric Acid Anhydrous (fine grade)8.008.008.00Glucose monohydrate (from EMDEX ®< )59.380.0052.26Oligosaccharides (from EMDEX ®< )3.130.002.75Dye (tatrazine)0.200.200.20Sodium Carbonate6.506.506.50Fragrance3.703.703.70Polyvinyl polypyrrolidone0.0064.637.50Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)13.5012.0013.50

[0070] Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0071] In all cases tablets of 6g were produced that were cylindrical in shape and had a diameter of 20mm.Results

[0072] The following results are for the compositions described in table 4. The results are the average of 5 tablets in each case. Table 5 - performance data (for tablets compressed at 147N / cm 2< )TestComparative CComparative DExample 2Disintegration time (min : secs)35:00 (stdev = 5:00)1:30 (stdev = 0)1:05 (stdev = 0:06)Tablet strength (kN)264 (stdev = 10.7)27 (stdev = 7.0)86 (stdev = 13.8)CommentDisintegration time too high for intended end useToo fragile to process Table 6 - performance data (for tablets compressed at 196N / cm 2< ) TestComparative CComparative DExample 2Disintegration time (min : secs)44:00 (stdev = 4:10)2:14 (stdev = 0:12)2:00 (stdev = 0:12)Tablet strength (kN)288 (stdev = 7.5)62 (stdev = 10.5)130 (stdev = 11.7)CommentDisintegration time too high for intended end useToo fragile to process Discussion of results

[0073] As can be seen in the results in tables 2, 3, 5 and 6 the inclusion of a low amount of PVPP results in a disintegration time and dissolution time that is comparable to a very high level of PVPP, whereas the tablet strength is comparable to a composition with a very high level of EMDEX. These trends are further exemplified in the figures in the application.

Examples

examples

Examples

[0064]

Table 1: Test tablets were produced using the following ingredients:

IngredientComparative A (wt%)Comparative B (wt%)Example 1 (wt%)

Sodium salt of linear alkyl benzene sulphonate (Ufaryl DL 80)4.134.134.13

Sodium methyl cocoyl taurate (Aquanate Cot 75)9.959.959.95

p-sodium cumene sulphonate (Eltesol SC93)2.932.932.93

Citric Acid Anhydrous (fine grade)202020

Glucose monohydrate (from EMDEX ®45.230.0038.10

Oligosaccharides (from EMDEX ®2.380.002.01

D62221F BLUE LF (Direct Blue 199)0.0330.0330.033

Sodium Benzoate6.06.06.0

Fragrance8.338.338.33

PVPP0.0047.587.50

Non-ionic surfactant - fatty alcohol polyglycol ether 25EO (Genapol T250)1.031.031.03

[0065]Fine grade of citric acid: particle size distribution: 90% of material is from mesh sizes 20 to 40.

[0066]In each case 5 cylindrical-shaped tablets of 6g with a diameter of 20mm were produced (height about 22-24mm).

[0067]The tablets were produced by adding the relevant ingredients one at a time into a suitable airtight c...

Claims

1. A detergent tablet comprising glucose monohydrate from 30 to 70 percent by weight, polyvinyl polypyrrolidone from 4 to 20 percent by weight and surfactant.

2. The detergent tablet according to claim 1 comprising from 10 to 50 percent by weight surfactant.

3. The detergent tablet according to any preceding claim with a total mass of from 2 to 10g.

4. The detergent tablet according to any preceding claim wherein the compression strength of the tablet is from 50 to 300N.

5. The detergent tablet according to any preceding claim capable of disintegration within 5 minutes or less when placed in water at 25°C, wherein the disintegration time is the time taken for 80% of the tablet to have broken away from the original structure.

6. A method of producing a liquid wash liquor comprising the steps of: a Combining water and a tablet according to any preceding claim in a container b Optionally, agitating the mixture7. A method according to claim 6 wherein the ratio of the tablet to water is in the range of 1:10 to 1:10,000 by weight or by volume.

8. Use of a detergent tablet according to any of claims 1-5 to form a wash liquor.

9. Use of a detergent tablet according to any of claims 1-5 to form a liquid wash liquor in 5 minutes or less.

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