GB2335434A - Encapsulated liquid incorporation in tableted compositions - Google Patents

Abstract

By correct selection of encapsulate particle size and regulation of the compression force as reflected in final tablet hardness measurements liquid-containing encapsulates can be successfully incorporated in to tableted detergent products for automatic dish washing and textile washing. The tablet will contain 0.1 to 10% of detergent liquid and the encapsulate is of a size between 0.01 and 100 microns.

Description

1 2335434 ENCAPSULATED LIQUID INCORPORATION IN TABLETED COMPOSITIONS

FIELD OF THE INVENTION

The present invention relates to encapsulated liquid detergent components that can be successfully incorporated in detergent tablet compositions.

BACKGROUND TO THE INVENTION

Detergent compositions are known in many physical forms including powders, liquids, pastes and tablets. Tablets or briquettes have advantages, for example, in that obtaining the correct product dosage is easier than with other product forms and product spillage is prevented. Blocks, tablets and briquets can be produced by a variety of methods, for example, casting, extrusion and coating powder with a binder layer. However, for large volume production compression of a powder composition to form a tablet is the most suitable and widely used method. In formulating such compositions for manufacture it is desirable for the product formulator to access the full range of detergent components. This gives rise to difficulties with components which are coated since they may be either unstable, volatile or need to be subject to a delayed release during a washing process, for example. This is because the act of compressing a powder brings all the components in to intimate contact which can serve to break the protective coating. This issue is primarily of relevance to encapsulated liquid components since solids particles are less deformable and more readily survive the compression process. In addition a liquid encapsulate need only be breached in one place to potentially release all the liquid. It is therefore desirable to have a method of successfully formulating liquids in a protective coating which will survive the tableting process.

It is an object of the present invention to obviate or mitigate the abovementioned disadvantages.

BACKGROUND ART

The incorporation of encapsulated liquid components in detergents formulations in the art largely concerns perfumes and perfumery components. For example, WO 97/1115 (Procter and Gamble) discloses the use of hygroscopic glassy particles containing a perfume and an optional carrier material. EP 0 346 034 (Unilever) describes the use of an encapsulation process based upon a hydrophobic wax for detergent components. Many examples are also present outwith the detergents field. However, no evidence of how these may successfully survive a tableting process is given and comparative examples herein show that a simple application of these technologies to tabletisation gives unsatisfactory results.

Perfume and other liquids retention in tabletised products has therefore been approached by 2 a variety of alternative methods. JP 53069840 (Fuji) teaches an external coating for the whole tablet. This method dose not segregate the liquid from the other tablet components. WO 93 08255 teaches the use of a specific perfume carrier adsorbent but does not teach the use of an impermeable barrier between a detergent and a liquid such as is found in a true encapsulate. EP 101402 (Henkel) teaches the segregation of perfumes by their incorporation in a plastifiable mixtures which can be co-extruded with another mixture to form a tablet. This method segregates the materials and limits their area of contact but does not put a barrier between them as such.

All of the identified prior art documents show an awareness of the issues of segregating and stabilising a detergent components, particularly perfumes and teach various methods of improving liquids formulation in tablets. Yet none teach a practicable method of incorporating an encapsulated liquid component in a tabled composition by compressing powder. It is thus an aim of the present invention to provide a tableted detergent composition wherein an encapsulated liquid component can be incorporated and is present after a tablet forming process based upon compression of a powder.

SUMMARY OF THE INVENTION

It has been surprisingly found that by judicious choice of encapsulate size that according to the present invention a detergent tablet composition formed by compression of a powder or powders containing between 0. 1 and 10% of a detergent liquid component incorporated as an encapsulate such that the encapsulate has a primary particle size of between 10Ogm and 0.0 1 gm. It is therefore noted that surprisingly not only an upper but also a lower particle size for successfully incorporating encapsulates has been found. In particular a size range of 1 Opm to 0. 0 1 [Am is preferable and even more preferably the size range of the encapsulate is from 1 Oim and 0. 1 pim which is surprisingly found in a dense tablet composition of greater than 0.75g/cc and even more surprisingly in compositions of greater than 1.0g/cc wherein it may be expected that much of the free space or porosity of the composition will have been eliminated and therefore applied pressure will be brought directly to bear on the fragile encapsulates.

DETAILED DESCRIPTION OF THE INVENTION

Thus according to the present invention the detergent composition is in a tableted form. As used herein the term tablet refers to a non particulate solid, which may be a bar, briquette, cake or tablet. In addition an encapsulate or a liquid is incorporated in the composition for the purposes of substantially segregating a liquid component ftom the other components of the composition when in a tablet form. As used herein the term encapsulate refers to a particulate material in which comprises a liquid or substantially liquid phase or phases surrounded completely by a barrier or membrane which is impermeable to the said liquid phase 3 material(s).

The encapsulated liquid may be any liquid with a detergent function examples being Liquid surfactants, (eg Syriperonic A3, A3 {ICI}) Bleach precursor (eg Glycerol triacetate) Antifoarn (eg poly dimethyl siloxane) Perfumes Perfume precursors (eg. esters of volatile aldehydes and ketones) also mixtures of the above or in combination with solid components such that the viscosity of the encapsulate remains essentially liquid, ie with a viscosity of less than 10 Pascal seconds at 20s-1 shear rate (as for example measured by a Haake viscometer with a cylindrical measuring cup and bob).

The encapsulating material may be any material which gives a particulate encapsulate where no part of the encapsulated liquid can directly contact its surrounding. It is recognised that in commercial production some encapsulate material will inevitably remain un-encapsulated and some coating remain unused. This invention does not therefore rely on the success of the encapsulation procedure or of the amount or proportion of any liquid or liquids present that have been encapsulated but on the presence of encapsulated material per se.

Suitable encapsulating materials are illustrated by the following nonlimiting examples:

Organic polymers - Addition polymers - eg Poly Vinyl; ethers, esters, amides, carboxylates, maleates, methacrylates, acrylates, alcohols, acetates and copolymers thereof.

- Condensation polymers - eg Poly; esters, and urethanes, gelatin, xanthan gums, guar gum, alginates.

Z:5 The encapsulates will typically consist of largely spherical structures filled at lest in part with the desired liquid, the remainder being either liquid vapour, air, nitrogen, argon or similar. These structures may consist of aggregates of multiples of these primary structures as may typically be produced during the encapsulation process.

The encapsulates may typically be produced by emulsifying the desired liquid in an other liquid, the introduction of an amphiphillic polymer or monomer which will reside largely at the interface of the droplets. This emulsion or suspension is then reacted to polymerise and / or cross link to form suspended encapsulate which is then used as such or removed by filtration, centrifugation or other suitable means.

To produce tablets containing two or more layers, the formulations for the first and second layers are produced separately and then introduced as separate layers into the die of a tableting press and co-compressed. The encapsulated component(s) may be in one or both 4 layers or may be split across the layers.

A pressure of 100 kPa to 1000 MPa will generally be suitable for forming the tablet. More preferably, a pressure of 200 kPa to 100 MPa is used and even more preferably one of 250kPa to 10 MPa, most preferably from 300 kPa to 5000 kPa.

There are a number of models of tableting press which are capable of producing dual layer tablets, for instance the "Excelapress" and "Rotapress" models are produced by BWI Manesty of Liverpool. It is also possible to modif, a single layer press to produce dual layer tablets, for instance an RS model, also ex Manesty, could be modified in this way. Other examples are the PH400 series ex Korsch of Berlin, the 3090 series ex Wilhem Fette of Hambury or model MOD BR680 ex J. Bonal S.A., Barcelona.

Tableting presses generally work by having a rotating circular turret with arrays of punches which compress the tablets from above and below. The cycle consists of filling the die with the powder which will make up one of the layers, optionally followed by filling with the powder of the second layer, compression of the tablet, and release.

Machines specially designed for dual layer operation usually have a small amount of pre-compression between filling the die with the powders of the first and second layers. This gives a sharper definition between the two layers which may be more aesthetically pleasing, particularly if the layers are of different colours.

The tableting press should be equipped with a feed mechanism so that the two powders are fed into the die in the weight ratio desired. Excess powder is removed from the area of the die by means of scrapers. The press should allow the tablet thickness to be adjustable. For a given die/punch size, this allows the tablet weight to be regulated.

The press should also have a control to regulate the applied force used in the main compression. The applied pressure should typically be about 0. 2 to 50 MPa, which for a 20 gram tablet would translate to an applied force per tablet of about 0. 18 to 45 kN. The pressure applied is a crucial part of the tableting operation as inadequate pressure will give a tablet which is not robust enough to withstand handling, while excess pressure gives a tablet which dissolves too slowly. The tablet strength may be monitored by use of equipment to measure its breaking strength under compression, such as the Holland CT5 automatic compression tester. The tablet is placed so that its smallest two opposite faces are placed between the compression bars. A 50 grain tablet should break at about 15- 150 kg applied force, as applied by pseudo static compressive breaking force between flat faced, parallel opposed anvils or circular cross section of 1 cm square which corresponds to about 500-5000 kPa. Such a measure can conveniently be taken using a Holland CT5 automatic compression tester.

Tablets produced in accordance with the invention will generally consist of a single layer or only the first and second layers as discussed above although we do not preclude the possibility of additional layers being present. The tablet may, for example, comprise the second layer sandwiched between two of the first layers. Each of the first and second layers will, in the depth dimension of the tablet, generally have a thickness considerably less than the other two dimensions so that in a two layer tablet the individual layers have major faces injuxtaposed face- to-face relationship. The first and second layers may, for example, have a major face of circular or rectangular shape. The tablet may typically weight about 20g to 60g and if desired the first and second layers may be differently coloured.

The detergent formulation in accordance with the invention will include at least one surface active agent which may, for example, be an anionic, cationic, non-anionic or amphoteric surface active agent. Any of the surface active agents widely used in detergent formulations may be employed in the present invention.

If an amphoteric surface active agent is used it may be present in the formulation in an amount of 0. 1 to 10% by weight, more preferably 0. 5 to 5%, even more preferably 1 to 4% on the same basis.

The amphoteric surface active agent may be betaine surface active agent. Preferred betaines may be either of the formula (I) or (H).

R' 1 W-W-CH2-COO- (1) R 2 R' R3CONI-ICH2CH2CH2N±CH2C001 (II) lc In the above formula, R' and W may be the same or different C, -4alkyl groups whereas R 3 is an alkyl group having 8-22 carbon atoms, more preferably 12 to 18 carbon atoms e.g.

mixed C 10 toC14.

The preferred betaine for use in the formulation of the invention is cocoamidopropyl 6 betaine.

An alternative amphoteric surface active agent for use in the formulation of the invention is a glycinate of the formula RSFICH2CO2H where R3 is as defined above.

Other suitable materials are as given in chapter 1 of "Amphoteric Surfactants", e.g. Lomax Ed, Marcel Decker, New York 1996.

A cationic surface active agent may also be employed as the surface active agent. The cationic surface active agent is preferably used in an amount of up to 20%, more preferably up to 10%, even more preferably up to 5% by weight of the formulation. by weight of the formulation. Examples of suitable cationic surface active agents include quaternary ammonium salts having three lower (C,,) alkyl groups (preferably methyl groups) and a long chain (C8-20) alkYl group, e.g. coco trimethyl ammonium chloride. Further examples include alkyl pyridinium. salts and other compounds in which the nitrogen atom of the pyridine assumes a quaternary form, e.g. as in an alkyl pyridinium bromide.

Further examples of cationic surface active agents which may, be used include amine and imidazoline salts.

If an anionic surface active agent is used then it is preferably present in the formulation in an amount of up to 20%, more preferably up to 10%, even more preferably up to 5% by weight of the formulation. Examples of anionic surface active agents which may be employed include alkylaryl sulphonates, alkyl sulphates, ether sulphates and ether carboxylates all as conventionally employed in laundry detergent formulations.

If a non-ionic surface active agent is used then it is preferably present in an amount of up to 25% by weight of the formulation, more preferably 2 to 15%, most preferably from 4 to 10% on the same basis. Examples of nonionic surface active agent which may be used include alkoxylates, ethylene oxide/propylene oxide block copolymers, alkanolamides (e.g. monoethanolamides and diethanolamides), esters and amine oxides.

The formulation may include at least one builder salt in a total amount of 10% to 50% by weight of the formulation. The builder may be for example be an alkali metal phosphate or alkali metal carbonate. A particularly preferred builder is sodium triphosphate.

7 It will be appreciated that the formulation may incorporate additional components as conventionally included in laundry detergent formulation. One example of such an additional component is a soap which may be used in an amount up to 5% by weight as a processing aid. Further examples include anti-foam agents, sequestrants (e.g. of the phosphonate type), whiteness maintenance agents (e.g. CMC, polyoxyethylene terephthalate, polyethylene terephthalate), colourants (e.g. dyestuffs), perfume, flow control agents (e.g. a sulphate) flow enhancer (e.g. a zeolite), pH regulators (e.g. a carbonate or bicarbonate), anti-corrosion agents, dye transfer inhibitors (e.g. PVP) and optical brighteners (e.g. Tinopal CBS- X and Tinopal DNIS-X). These components may, for example, each be present in amounts up to 1% by weight of the formulation.

The builder may, for example, be an alkali metal polyphosphate, an alkali metal carbonate, alkali metal bicarbonate, alkali metal citrate, zeolite or a crystalline or amorphous silicate builder system. Zeolites 4A and A24 are examples. A zeolite builder will typically be supplemented by a polycarboxylate or citrate co-builder. If a polycarboxylate co-builder is used it may optionally be derived from material used to encapsulate the liquid component. Mixtures of these builder systems may be used.

It is particularly preferred that the builder is sodium tripolyphosphate. If the tablet contains more than one layer the sodium tripolyphosphate for the first layer (i.e. the layer which dissolves more quickly) may for example be STP GL (ex Kemira Chemle) or STP PC (ex Albright and Wilson) whereas that for the second layer may be STP P (ex Albright and Wilson).

It is preferred (but not essential) that the builders of the layers are chemically the same.

The bleaching system may be an activated bleaching system which may comprise a compound which generates hydrogen peroxide on dissolution in water together with a bleach activator. The hydrogen peroxide compound may, for example, be an inorganic persalt, e.g. a perborate (in the monohydrate and/or tetra hydrate form), a percarbonate or a persulphate. The alkali metal salts of these compounds are preferred, particularly sodium and potassium salts. The bleach activator may be a compound incorporating aliphatic acyl groups preferably having two or three carbon atoms, the acetyl group being preferred. Examples of suitable bleach activators are tetraacetylethylene diamine (TAED) and acetylated polyols such as acetylated sugars (e.g. penta acetyl glucose, fructose etc.) and acetylated sugar derivatives (e.g. acetylated sorbitol and acetylated mannitol). All of these specific bleach activators are capable of reacting with hydrogen peroxide to generate peracetic acid as an active bleaching species.

The tablet will comprise a surface active agent such as conventionally used for automatic dish washing, textile washing or detergent formulations. Generally the surface 8 active agent will be incorporated in the second layer. Alternatively or additionally either of the layers may include a surface active agent. it is particularly preferred that the surface active agents employed in the tablets are non-ionic surface active agents such as available under the trade name Syriperonic. Further examples of surfactants which may be used include Lutensol A03 or A07 (ex BAS17), Plurafac, LF404 or LF244 (ex BASF) or Dobanol 91-7 or 91-3 (ex Shell).

Further ingredients which may be present in the composition, either homogeneously or in separately are:

(1) soil suspension agents (e.g. Disilicate) (ii) anti-corrosion agent (e.g. Disilicate) (iii) source of alkalinity (e. g. sodium carbonate) (iv) crystal growth inhibitors (e.g. a phosphonate) (v) anti-tamishing agents (e.g. benzatriazole). (vi) bleach scavengers (e. g. ammonium sulphate, sodium, potassium or ammonium glutamate or sodium or potassium bisulphite).

(vii) water softening agents (e.g. a phosphate or polycarboxylate) (viii) fat emulsifier (e.g. a non-ionic surfactant) (1x) binder (e.g. ethylene glycol) (x) perfume (xi) dye An automatic dish washing composition may, for example, comprise Builders (e.g. phosphate, carbonate, zeolite) Hydrogen Peroxide Precursor Compound Surfactant Soap Phosphonate Polymer Perfume Enzymes Corrosion Inhibitor 10% to 90% of at least a portion of the builder is provided by silicate.

Binder / Disintegrant 10% to 80 5% to 20% up to 25% 0% to 4% 0. 1 % to J3 0% to 4% 0% to 3% 0% to 10 0.01% to 1 Optionally, the particles of ingredients of the detergent base powder may be coated with 9 binder/disintegrant. However, particles of ingredients which are typically post-dosed, for example bleach, enzymes, are preferably not coated with binder/disintegrant.

Use of a binder helps to hold the tablet together, thus enabling it to be made using a lower compaction pressure and making it inherently more likely to disintegrate well in the wash liquor. If the binder is also a material that causes disruption when contacted with water, even better disintegration properties may be achieved.

Tablet disintegrants are well known in the pharmaceutical art and are known to act by four principle mechanisms: swelling, porosity and capillary action (wicking), and deformation (all physical), and effervescence (chemical). Tablet disintegrants in the pharmaceutical industry are described in W Lowenthal, Journal of Pharmaceutical Sciences Volume 6 1, No. 11 (November 1972).

Physical disintegrants are suitable. These include organic materials such as starches, for example, corn, maize, rice and potato starches and starch derivatives, such as Primojel (Trade Mark) carboxymethyl starch and Explotab (Trade Mark) sodium starch glycolate; celluloses and cellulose derivatives, for example, Courlose (Trade Mark) and Nymcel (Trade Mark) sodium carboxymethyl cellulose, Ac-di-Sol (Trade Mark) cross- linked modified cellulose, and Hanfloc (Trade Mark) microcrystalline cellulosic fibres. and various synthetic organic polymers, notably polyethylene glycol; cross linked polyvinyl pyrrolidone, for example, Polypiasdone (Trade Mark) XL or Kollidon (Trade Mark) CL. Inorganic swelling disintegrants include bentonite clay.

The binder/disintegrant may suitably be applied to the particles by spraying on in solution or dispersion form. Some disintegrants may additionally give a functional benefit in the wash, for example, supplementary building, antiredeposition or fabric softening.

Preferred binder/disintegrants are polymers. A more preferred binder/disintegrant is cross linked polyvinyl pyrrolidone, for example, Kollidon (Trade Mark) CL or PolypIasdone (Trade Mark) XL.

The binder/disintegrant is preferably used in an amount within the range of from 0. 1 to 10 wt%, more preferably from 1 to 5 wt9/o.

Effervescent (chemical) disintegrants Effervescent disintegrants may be included to help break up the tablet, these include weak acids or acid salts, for example, citric acid, maleic acid or tartaric acid, in combination with alkali metal carbonate or bicarbonate; these may suitably be used in an amount of from 1 to 25 wt%, preferably from 5 to 15 wt%. Further examples of acid and carbonate sources and other effervescent systems are detailed in Pharmaceutical Dosage Forms: Tablets, Volume 1, 1989, pages 287-291 (Marcel Dekker Inc, ISBN 0-8247-8044-2).

EXAMPLES The invention will be fin-ther described with reference to the following non-limiting examples. Encapsulates ID Liquid core Coating material Average particle size CYVA. 100 Citronellol Polyvinyl alcohol, poly 100im (racemic mixture) vinyl acetate copolymer (ex Aldrich chem co.) (80/2 CYVA.22 Citronellol ditto 22im C.PVA.02 Citronellol ditto 2tm CYVA.0.1 Citronellol ditto 0. 1 pim WLYVA. 15 White Line commercial ditto 15im perfume ex Pheonix fragrances, Northants UK.

% Coating by weight 10%, liquid 90%.

Average particle sizes can be measured on a Coulter counter time of transition particle size measuring apparatus with light scattering adjustment for lower particle sizes. Suitable encapsulates can be manufactured by Celessence International Ltd, UK.

Composition 1 (Automatic dish washing composition) Component % by weight Sodium Tripoly to 100% phosphate Sodium Disilicate Heavy Gran 25.0 Granular Sodium Carbonate 8.40 Sodium Perborate 12.5 Polyvinyl pyrrolidone MW 25,000 10.0 50% solution Dequest 2016D 0.40 Benzotriazole 0.20 Polyethylene Glycol 0.20 TAED 3.00 Synperonic LF/RA 260 33.00 Glycerol triactete / GTA encapsulate of 85% 5.00/6.00 active GTA (see table) The composition was mixed to form a homogeneous powder using a low shear mixing process (Lodige ploughshare horizontal mixer) for 5 minutes. The mixture was then compressed in 11 to tablets of 36min long by 26mm wide and weighing 20grammes at the pressure indicated. The encapsulating material used was a cross linked polyacrylate.

Tablet physical parameters Top value: hardness values in Newtons. Bottom value: Tablet density in glcc Composition 2 Pressure in kPa to form the tablet 670kPa 1340 3350 5025 6700 Liquid GTA 12 20 45 60 90 0.5% 0.86 1.04 1.32 1.52 1.58 Encapsulate 0.55% inclusion GTAMM. 110 14 21 47 68 94 0.96 1.17 1.22 1.55 1.58 GTAMM.20 12 21 47 65 98 1.33 GTAMM.02 12 22 48 68 97 0.88 1.22 1.45 1.56 1.59 GTAMM.0. 1 13 20 48 61 90 GTA.Gel.18 12 21 50 69 98 Perfume used for WL was 'White Line' ex Pheonix Fragrances, UK. The encapsulating material was a high molecular weight gelatine.

12 Peracetic acid released in water at 80-C (TOP FIGURE) 15'C (BOTTOM FIGURE) after 5 minutes as compared to liquid GTA scored at 100%.

Composition 2 Pressure in kPa 670kPa 1340 3350 5025 6700 Liquid GTA 100 100 100 100 100 0.5% Encapsulate 0.55% inclusion GTA.MM. 110 91 90 92 96 98 28 45 90 90 89 GTA.MM.20 95 91 97 92 98 0 0 0 GTA.MM.02 98 95 98 90 98 0 0 0 15 45 GTA.MM.0.1 98 90 96 90 96 38 GTA. Gel. 18 100 100 100 100 100 0 0 0 70 80 Key # GTA - Encapsulated liquid, MM - Poly methyl methacrylate/ acrylic acid copolymer 80/20 encapsulating medium, PVA Poly vinyl acetate encapsulation medium, Gel - Gelatine encapsulating medium. Final figure is the primary particle size in pt metres. Eg. 15 = 15 gm. This table demonstrates the efficacy of the encapsulation after tableting when specific particle size encapsulates are used.

13 Composition 2 (Textile washing composition) RAW MATERIAL Percentage SODIUM TR.1POLYPHOSPHATE 32% LIGHT SODIUM CARBONATE To 100% PERBOR-ATE TETRA HYDRATE 22% SODIUM CARBOXY METHYL CELLULOSE 2% TINOPAL DMS-X (FLUORESCER) 0.2% TINOPAL CBS (FLUORESCER) 0.1% PROTEASE ENZYME 0.7% AMYLASE ENZYME 0.7% CELLULASE ENZYME 0.7% POLY DIMETHYL SILOXANE 0.4% SODIUM SILICATE 2% TETRA ACETYL ETHYLENE DLAMINE 3% 7E0 ALKYL ETHOXYLATE 5% SODIUM ALKYL BENZENE SULPHONATE 10% 40% SODIUM SILICATE SOLUTION (BINDER) 12% PERFUME SEE TABLE ENCAPSULATE SEE TABLE The silicate is sprayed on to the powder whilst mixing under low shear in a Lodige ploughshare mixer to give a granular powder for agglomeration. This was then tableted at the specified pressure to form a tablet of 44nun diameter and 50g weight.

14 HARDNESS VALUES IN NEWTONS.

Composition 2 Pressure in kPa to form the tablet 670 1340 3350 5025 6700 Citronellol 15 67 188 309 414 0.5% Encapsulate 0.55% inclusion CYVA.100 15 70 200 300 415 CYVA.22 15 68 199 310 409 CYVA.02 15 71 195 302 410 CYVA.0.1 15 72 200 300 412 WLYVA. 15 14.5 70 215 305 410 Perfume used for WL was 'White Line' ex Pheonix Fragrances, UK. The encapsulating material was a high molecular weight gelatine. With 15% perfume by weight.

c The C encapsulates contained Citronellol at 90% by weight.

Perfume intensity scores VALUES as a percentage score of intensity of the Composition 2 Pressure in kPa 670 1340 3350 5025 6700 Citronellol 100 100 100 100 100 0.5% encapsulate 0.55% inclusion CYVA. 100 10 30 50 50 80 CYVA.22 0 0 0 20 35 C.PVA.02 0 0 0 15 330 CYVA.0.1 0 0 10 330 45 WLYVA.15 0 0 0 15 20 Perfume used was 'White Line' ex Pheonix Fragrances, UK.

Perfume intensity was scored using a panel of 5 people. Each person was asked to rank the intensity of the perfume as compared to the control of the unencapsulated perfume as a percentage. This table also demonstrates the efficacy of the encapsulation after tableting when specific particle size encapsulates are used.

16

Claims (13)

1) A detergent tablet composition formed by compression of a powder or powders containing between 0. 1 and 10% of a detergent liquid component incorporated as an encapsulate such that the encapsulate has a primary particle size of between 1 001Am and 0.0 1 im.

2) A detergent tablet composition formed by compression of a powder or powders containing between 0. 1 and 10% of a detergent liquid component incorporated as an encapsulate such that the encapsulate has a primary particle size of between 10pm and 0.0 1 pim and has a compressed density greater than 0.75g/cc.

3) A detergent tablet composition formed by compression of a powder or powders containing between 0. 1 and 10% of a detergent liquid component incorporated as an encapsulate such that the encapsulate has a primary particle size of between 1 Oim and 0. 1 Lm and the density of the tablet is greater than 1.0g/cc and less than 1.50g/cc.

4) A composition according to claims 1 to 3 whereby the wall thickness of the encapsulate is no greater than 5 0 im.

5) A composition according to claims 1 to 4 where the wall thickness of the encapsulate is no greater than 2 5 im.

6) A composition according to claims 1 to 4 where the tablet has a static compressive breaking strength (hardness) between opposed anvils of 1 cm square of more than 10 NeAlons.

7) A composition according to claims 1 to 4 where the tablet has a static compressive breaking strength (hardness) between opposed anvils of 1 cm square of more than 20 NeAlons.

8) A composition according to claims 1 to 7 where the encapsulating material is an organic condensation or addition polymer.

9) A composition according to claims 1 to 7 where the encapsulated liquid has a melting point of less than 2TC.

10) A composition according to claims 1 to 7 where the encapsulated liquid has a melting point of more than 2TC and the tablet is formed at a temperature below the melting point of the liquid.

11) A composition according to any of claims 1 to 10 where the liquid is a liquid other than a perfume or perfume component or precursor, preferably a surfactant, bleach precursor, 17 peroxy bleach, antifoam, rinse aid or other liquid detergent component.

12) A composition according to any of claims 1 to 10 where the liquid is not a perfume or perfume component or precursor.

13) A composition according to any of the preceding claims where the tablet is for textile or automatic dish washing wherein it comprises not less than 30% by weight sodium triphosphate and other detergents salts of not less than 50% by weight which is formed by a compressive force of greater than 1000 Pascals pressure to yield a tablet of greater than 100 Newtons static compressive breaking strength (hardness) when broken between opposed anvils of 1 cm square.