GB2432851A - Laundry composition including polymer particles containing perfume and a non-ionic deposition aid - Google Patents

Abstract

Polymer particles comprising a benefit agent, preferably a sugar polyester are delivered to fabric during laundering and give long lasting adherence of the benefit agent to fabric during laundering. The particle comprises a benefit agent and a polymer and is prepared using miniemulsion polymerisation. A method of depositing a benefit agent, preferably a sugar polyester, onto a substrate by means of such a composition is also disclosed.

Description

<p>LAUNDRY COMPOSITION</p>

<p>TECffl1ICAL FIELD</p>

<p>The present invention relates to polymer particles comprising a perfume, a benefit agent, which is preferably a sugar polyester, and a nonionic deposition aid and their uses, such as delivery of the perfume to fabric during laundering. Laundry treatment compositions containing particles according to the invention, provide deposition efficiency benefits during washing.</p>

<p>BACKGROUND OF THE INVENTION</p>

<p>The deposition of a perfume onto a substrate, such as a fabric, is a well known method of imparting perfume properties to the substrate. In laundry applications deposition of a perfume is used, for example, during fabric treatment processes such as fabric conditioning. Methods of deposition are diverse and include deposition during the wash or rinse stages of the laundry process or direct deposition before or after the wash, such as by spraying or rubbing or by use of impregnated sheets during tumble drying or water additives during steam ironing.</p>

<p>The perfume is often incorporated into a carrier or delivery system. Carrier systems for perfumes are typically based on encapsulation or entrapment within a matrix. The perfume may simply be emulsified but problems with poor retention or stability exist and deposition onto a substrate, such as fabric, is often inefficient. Diffusion of the perfume into a carrier suffers from complex preparation including time of diffusion; poor retention of the perfume in the matrix and subsequent poor substrate deposition are also common problems.</p>

<p>After deposition onto a surface, a problem exists in that longevity of adherence to that surface of the perfume, in a surfactant containing environment, is inherently poor because surfactants are characteristically very efficient at combining with perfumes. This results in a perfume which has been deposited onto a fabric being washed off during a main wash, or in the perfume being leached from its carrier in the wash liquor thus becoming unavailable for deposition onto the fabric. Protection of the perfume is, therefore, required before and after it has been deposited onto a surface. In the context of laundry products, the need for protection from surfactants of perfumes promotes the need for new protection systems. By protection benefit as used herein is meant protection of the perfume from the action of surfactants during a wash process, for example as suggested above. Thus the protection of perfumes within a formulation in an aqueous environment and longevity of the perfume deposited onto a fabric are both desirable goals.</p>

<p>Protection from the action of surfactants and longevity of deposition on a substrate are particular needs for perfumes as the volatile nature and low molecular weight of perfume components make them susceptible to diffusing out of carrier systems during laundering and evaporating quickly from substrates after deposition.</p>

<p>PRIOR ART</p>

<p>Our co-pending patent application, PCT/EP2005/004779, unpublished at the filing date of this application, is directed towards a process, which uses miniemulsion polyinerisation, for the preparation of polysaccharide/ polymer conjugate particles containing a lubricant. Certain particles produced by the process and uses thereof are also disclosed. The particles facilitate deposition of the lubricant to fabric during the main wash part of a laundering process.</p>

<p>Our co-pending patent applications, GB 0513803.7 and GB 051805.2, both unpublished at the filing date of this application, are directed towards miniemulsion polymer particles (with and without a shell respectively) comprising a benefit agent, preferably a sugar polyester, which may be delivered to fabric during laundering. These particles give long lasting adherence of the benefit agent to fabric during laundering.</p>

<p>We have now surprisingly found that a perfume can be efficiently deposited onto a fabric if a carrier system based on a colloidal particle comprising a polymer, a perfume and a nonionic deposition aid, such as locust bean gum is employed. The carrier system further provides protection and longevity of adherence to the perfume.</p>

<p>DEFINITION OF THE INVENTION</p>

<p>A first aspect of the invention provides a polymer particle comprising a perfume, a benefit agent, and a polymer comprising monomer units which are derived from monomers selected from the group consisting of:-a) monomers with a solubility in water of less than 0.1 g/l, and/or b) monomers with a solubility in water of from 0.1 to 30 g/l, and c) optionally, monomers with a solubility in water of greater than 30 g/l, and/or d) optionally, cross linkers; and wherein the particle further comprises a nonionic deposition aid.</p>

<p>A second aspect of the invention provides a process for the preparation of the particles according to the first aspect, which comprises miniemulsion polymerisation of monomers.</p>

<p>A third aspect of the invention provides a laundry treatment composition comprising the particles of the first aspect.</p>

<p>Use of this laundry treatment composition to provide a perfume deposition benefit to fabric is also provided.</p>

<p>In a fourth aspect, the invention provides the use of a particle of the first aspect to provide a perfume deposition benefit during a laundry process.</p>

<p>In a further aspect, the invention provides the use of a particle of the first aspect in the manufacture of a laundry treatment composition to provide a perfume deposition benefit during the laundry process.</p>

<p>In a still further aspect, the invention provides an aqueous wash medium comprising from 0.05 to 1 gram per litre of a particle according to the first aspect of the invention.</p>

<p>DETAILED DESCRIPTION OF THE INVENTION</p>

<p>The present invention is directed towards polymer particles, comprising a core, wherein the core comprises perfume, a benefit agent and a polymer, which comprises monomer units; the particles further comprise a nonionic deposition aid.</p>

<p>The polymer particles of the invention are usually approximately spherical and of typical colloidal dimensions.</p>

<p>Particle diameters may range from about 30 to 500 nm (The Encyclopaedia of Polymer Science and Engineering, Second Edition, Volume 8, Page 647, John Wiley and Sons Inc. (1987)) Where the particles of the invention are described herein as latex particles, the term "latex" or "latex particle" is defined as a stable colloidal dispersion of a polymeric substance in an aqueous medium.</p>

<p>The polymer particles of the invention can comprise a wide range of monomeric units. By "monomer units" as used herein is meant the monomeric units of the polymer chain, thus references to "a polymer particle comprising insoluble monomer units" as used herein means that the polymer particles is derived from insoluble monomers, and so forth.</p>

<p>The monomer units are derived from monomers which are suitable for free radical polymerisation. Therefore, preferably the monomer contains at least one ethylenically unsaturated group capable of undergoing addition polymerisation.</p>

<p>The monomers may be selected according to their solubilities such that the polymer comprises monomer units which are derived from monomers selected from the group consisting of:-a) monomers with a solubility in water of less than 0.1 g/l, and/or b) monomers with a solubility in water of from 0.1 to 30 g/l, and c) optionally, monomers with a solubility in water of greater than 30 g/l, and/or d) optionally, cross linkers.</p>

<p>By insoluble as used herein in reference to monomers, is meant that the material is soluble in water (distilled or equivalent) at a concentration of less than 0.1 g/litre, at 25 C, i.e. monomers of type (a) above.</p>

<p>By low solubility as used herein in reference to monomers, is meant that the material is soluble in water (distilled or equivalent) at a concentration in the range of from 0.1 to g/litre, at 25 C, i.e. monomers of type (b) above.</p>

<p>By high solubility as used herein in reference to monomers, is meant that the material is soluble in water (distilled or equivalent) at a concentration of greater than 30 g/litre, at 25 C, i.e. monomers of type (c) above.</p>

<p>The particle of the invention may further comprise a shell, which comprises monomer units selected from (b), and optionally (c) and/or optionally (d).</p>

<p>Monomers The polymer comprises monomer units which are derived from monomers that are capable of undergoing free radical polymerisation. Suitable classes of such monomers are given in the group consisting of olefins, ethylene, vinylaromatic monomers, esters of vinyl alcohol with mono-and di-carboxylic acids, esters of a,-monoethylenically unsaturated mono-and dicarboxylic acids with alcohols, nitriles of a,3-monoethylenically unsaturated carboxylic acids, conjugated dienes, a,3-monoethylenically unsaturated monocarboxylic and dicarboxylic acids and their amides, methacrylic acid and its esters with alcohols and diols, acrylic acid and its esters with alcohols and diols, dimethyl or di-n-butyl maleate, and vinyl-sulfonic acid and its water-soluble salts, and mixtures thereof. The polymer particle may comprise mixtures of monomer units.</p>

<p>The polymer particle may optionally comprise monomers which are cross-linkers. Such crosslinkers may have at least two non-conjugated ethylenically unsaturated double bonds.</p>

<p>Examples are alkylene glycol diacrylates and dimethacrylates. A further type of suitable cross-linking monomers are those that are conjugated, such as divinyl benzene. If present, these monomers constitute from 0.1 to % by weight, based on the total amount of monomers to be polymerised.</p>

<p>The monomers a), b), c) and d), as defined above, are preferably selected from the following:-a) vinyl octate; Vinyl decanote; vinyl laurate; vinyl stearate; esters of acrylic, methacrylic, maleic, fumaric or itaconic acid with decyl, dodecyl, tetadecyl, hexadecyl and octadecyl alcohol, b) styrene; a-methylstyrene; o-chlorostyrene vinyl acetate; vinyl propionate; vinyl n-butyrate; esters of acrylic, methacrylic, maleic, fumaric or itaconic acid with methyl, ethyl, n-butyl, isobutyl, n-hexyl and 2-ethylhexyl alcohol; 1,3-butadiene; 2,3 dimethyl butadiene; and isoprene, c) acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, poly (alkylene oxide) monoacrylates and monomethacrylates, N-vinyl-pyrrolidone, methacrylic and acrylic acid, 2-hydroxyethyl acrylates and methacrylates, glycerol acrylates and methacrylates, poly(ethylene glycol) methacrylates and acrylates, n-vinyl pyrrolidone, acryloyl morpholine, vinyl formamide, n-vinyl acetamide and vinyl caprolactone, acrylonitrile (71 gIl), acrylamide, and methacrylamide at levels of less than 10 % by weight of the monomer unit content of the particle; 2-(dimethylamino) ethyl methacrylate, 2- (diethylamino) ethyl methacrylate, 2-(tert-butylamino) ethyl methacrylate, 2 -aminoethyl methacrylate, 2-(2-oxo-l-imidazolidinyl) ethyl methacrylate, vinyl pyridine, vinyl carbazole, vinyl imidazole, vinyl aniline, and their cationic forms after treatment with alkyl halides; d) vinyltoluenes, divinyl benzene, ethylene glycol diacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylates, ethylene glycol dimethacrylate, 1,2-propylene glycol dimethacrylate, 1, 3-propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, methylenebisacrylamide, cyclopentadienyl acrylate, and triallyl cyanurate.</p>

<p>The polymer particle may comprise monomer units, which are derived from monomers selected from the group consisting of butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethyihexyl acrylate, 2-ethyihexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, styrene, vinyl acetate and divinyl benzene, or mixtures thereof.</p>

<p>Particles of the invention can be optionally comprise monomer units which are derived from monomers of solubility -10 -of greater than about 30 g/litre, preferably greater than 35 g/litre, for example 40 to 45 g/litre in water (distilled or equivalent) at 25 C. Such monomers may be utilised in a monomer mixture at levels of up to 10 % based on weight of monomers used.</p>

<p>The Deposition Aid The polymer particle of the invention comprises a deposition aid, which is nonionic.</p>

<p>Preferably, the deposition aid is a polysaccharide. The polysaccharide preferably has a 1-1,4-1inked backbone.</p>

<p>Preferably the polysaccharide is a cellulose, a cellulose derivative, or another -1,4-linked polysaccharide having an affinity for cellulose, such as polymannan, polyglucan, polyglucomannan, polyxyloglucan and polygalactomannan or a mixture thereof. More preferably, the polysaccharide is selected from the group consisting of polyxyloglucan and polygalactomannan. For example, preferred polysaccharides are locust bean gum, tamarind xyloglucan, guar gum or mixtures thereof. Most preferably, the deposition aid is locust bean gum.</p>

<p>The polysaccharide acts as a delivery aid/deposition agent for the particle.</p>

<p>Preferably, the polysaccharide backbone has only 1-1,4 linkages. Optionally, the polysaccharide has linkages in addition to the B-1,4 linkages, such as 1-1,3 linkages.</p>

<p>-1] -Thus, optionally some other linkages are present.</p>

<p>Polysaccharide backbones which include some material which is not a saccharide ring are also within the arnbit of the present invention (whether terminal or within the polysaccharide chain).</p>

<p>The polysaccharide may be straight or branched. Many naturally occurring polysaccharides have at least some degree of branching, or at any rate at least some saccharide rings are in the form of pendant side groups (which are therefore not in themselves counted in determining the degree of substitution) on a main polysaccharide backbone.</p>

<p>Preferably, the polysaccharide is present at levels of between 0.1% to 10% w/w by weight of the total amount of the particle.</p>

<p>The deposition aid, which is preferably a polysaccharide, is attached to the polymer particle (with or without shell).</p>

<p>Attachment may be by means of a covalent bond, entanglement or strong adsorption, preferably by a covalent bond or entanglement and most preferably by means of a covalent bond. By entanglement as used herein is meant that the deposition aid is adsorbed onto the particle as the polymerisation proceeds and the particle grows in size, part of the adsorbed polysaccharide becomes buried within the interior of the particle. Hence at the end of the polymerisation, part of the polysaccharide is entrapped and bound in the polymer matrix of the particle, whilst the remainder is free to extend into the aqueous phase.</p>

<p>-12 -By strong adsorption as used herein is meant strong adsorption of the polysaccharide to the surface of the particle; such adsorption can, for example, occur due to hydrogen bonding, Van Der Waals or electrostatic attraction between the polysaccharide chains and the particle.</p>

<p>The deposition aid is thus mainly attached to the particle surface and is not, to any significant extent, distributed throughout the internal bulk of the particle. This is distinct from graft copolymers in which e.g. a polysaccharide may be grafted along the length of a polymer chain. A particle which is formed from a graft copolymer would, therefore, contain polysaccharide throughout the internal bulk of the particle as well as on the particle surface and the present invention is not intended to cover such a particle. Thus the particle which is produced when using a polysaccharide as the deposition aid according to the process of the invention can be thought of as a "hairy particle", which is different from a graft copolymer. This feature of the invention provides significant cost reduction opportunities for the manufacturer as much less polysaccharide is required to achieve the same level of activity as systems which utilise polysaccharide copolymers.</p>

<p>Optional Shell The particles of the invention may optionally comprise a shell which is situated between the core and the deposition aid. The particle thus has core-shell morphology. Like the core, the shell comprises monomer units which are derived from monomers that are capable of undergoing free radical -13 -polymerisation. The shell comprises monomer units selected from b), and optionally c) and/or optionally d) as described above. The monomer units of the core may be the same as or different from the monomer units of the shell and both the core and the shell may comprise mixtures of monomer units.</p>

<p>Like the core, the shell may optionally comprise monomers which are cross-linkers as described above. The shell preferably covers 50 to 100 % of the surface area of the core, most preferably 95 to 100 %.</p>

<p>The ratio of core to shell by weight may be from 1:1 to 100:1, preferably 2:1 to 20:1 The polymer, perfume and benefit agent must be compatible, i.e. phase separation should not occur when the polymerisation of the monomer (which is mixed with the perfume and benefit agent) is carried out during the process of the invention. The person skilled in the art will be able to determine which are compatible by performing simple tests, for example, a simple test would be to carry out the polymerisation to form a latex, let a sample of the newly formed latex dry into a thin film and look for visual evidence of phase separation -if the film is clear, they are compatible, if opaque they are incompatible. Where an incompatibility exists, dilution of an incompatible polymer with a compatible one may improve its compatibility.</p>

<p>Perfumes The polymer particle of the invention comprises a perfume.</p>

<p>The perfume is present in an amount of from 1 to 50 % by -14 -total weight of the particle, preferably from 10 to 50 % by total weight of the particle.</p>

<p>The perfume suitably has a molecular weight of from 50 to 500.</p>

<p>The perfume suitably has a boiling point of from 30 to 500 degrees Centigrade.</p>

<p>The Benefit Agent The polymer particle further comprises a benefit agent.</p>

<p>A wide range of benefit agents may be used in the present invention. Suitably, the benefit agent may be selected from the group consisting of fabric softeners, conditioners, soil release polymers, shape retention agents, anti-crease agents, ease of ironing aids, quick drying aids, lubricants, texturising agents, insecticides, insect repellents, fungicides, photofading inhibitors, dyes, pigments, fluorescers, and sunscreens, or mixtures thereof. Benefit agents are preferably chemical and/or mechanical protective agents, such as fabric softeners, conditioners, shape retention agents, anti-crease agents, ease of ironing aids, lubricants, texturising agents, insecticides, insect repellents, fungicides, photofading inhibitors and sunscreens, or mixtures thereof. Cosmetic and pharmaceutical benefit agents may also be used.</p>

<p>More preferably, the benefit agent is a lubricant, such as a silicone, mineral oil, vegetable oil and sugar polyester.</p>

<p>-15 -Most preferably, the benefit agent is a biodegradeable lubricant, such as a vegetable oil and a sugar polyester. A highly preferred lubricant in the context of the present invention is a sugar polyester (SPE). They are known in fabric conditioners and/or softeners. These materials are non-toxic and inherently biodegradable.</p>

<p>Typically these materials are the products obtainable by esterification of a sugar, such as a saccharide (or other cyclic polyol), with a fatty material. In the context of the invention, the sugar is preferably a disaccharide, preferably sucrose, that is esterified with fatty acid, wherein the degree of esterification is from 1 (mono) to 8 (octa). The fatty acid preferably has a chain length of from C12 to C22 and may be monounsaturated. Examples of suitable fatty acids are Lauric (Cl2), Myristic(C14), Palmitic(C16), Stearic(C18), Oleic(C18:1), Behenic(C22) and Erucic(C22:1) The Hydrophilic-Lipophilic Balance (HLB) value of the SPE's that are suitable for use in the invention are suitably from 0 to 4, preferably from 0 to 2. HLB is a well known parameter to those skilled in the art and a literature reference is: "Modern Aspects of Emulsion Science", The Royal Society of Chemistry, 1998, page 179.</p>

<p>Sugar polyesters can be represented by the formula below:-C12H1403 (OR) (OH) 8-n -16 -where R = COCH2+1 or COCH2.1 (for monounsaturated fatty acids) Preferred sugar polyesters are sucrose polyesters.</p>

<p>Preferred sucrose polyesters are selected from sucrose tetrastearate and sucrose tetraerucate, sucrose tetralaurate, sucrose tetraoleate, sucrose tetrapalmitate and sucrose tetrapaim kernal, most preferably sucrose tetraerucate. It should be noted that these sucrose polyesters normally contain a spread of degree of substitution on the saccharide rings, for example, sucrose tetrastearate also comprises tristearate, pentastearate, hexastearate, etc. Furthermore, the sugar polyesters may contain traces of surfactant which is separate from the main surfactant and the co-surfactant. The SPE can be a mixture of different fatty acids, such as a mixture of oleate and stearate, for example, palm kernal contains a mixture of lauric acid, stearic acid, myristic acid, palmitic acid and oleic acid.</p>

<p>A highly preferred sugar polyester for use in the present invention is ER-290 ex Mitsubishi Ryoto, which is a sucrose tetraerucate and according to the manufacturers spec is mainly Pentaerucate, Tetraerucate and Hexaerucate and has a HLB value of 2.</p>

<p>The lubricant (such as a sugar polyester) can be incorporated into the particle at a wide range of levels.</p>

<p>For example, of from 0.1 to 99 %, preferably from 50 to 99 % by weight of the total particle.</p>

<p>-17 -Further suitable lubricants are amino functional silicone oils such as Rhodorsil Oil Extrasoft supplied by Rhodia Silicones. Other silicones may be selected from those disclosed GB l,549,180A, EP 459, 82lA2 and EP 459822A. Other suitable lubricants include any of those known for use as dye bath lubricants in the textile industry.</p>

<p>The Polymer Particle The polymer particle may be used in the treatment of fabric.</p>

<p>The treatment provides a perfume benefit. Such treatment may also provide a softening, conditioning, lubricating, crease reducing, ease of ironing, moisturising, colour preserving and/or anti-pilling, quick drying, UV protecting, shape retaining, soil releasing, texturising, insect repelling, fungicidal, dyeing, and/or fluorescent benefit to the fabric, depending on the benefit agent and the monomers used.</p>

<p>Alternatively, the polymer particle may be incorporated into a laundry treatment composition and used in the treatment of fabric.</p>

<p>The particle may be used in the manufacture of a laundry treatment composition to provide a perfume benefit during a laundry process.</p>

<p>Processes for Preparation Any suitable process may be employed for the preparation of the particles of the invention. A suitable process for the -18 -preparation of the polymer particle of the invention is one that comprises miniemulsion.</p>

<p>Preferred processes are the so-called "hybrid" or "artificial" routes as detailed in "Miniemulsion Polymerisation", F. Joseph Schork, Yingwu Luo, Wilfried Smuldes, James P. Russian, Alessandro Butte and Kevin Fontenot, Adv. Polymer Sci (2005) 175: 129-255, and "Emulsion Polymerisation and Emulsion Polymers" Wiley, 1st Edn., 1997, Ed Peter Lovell and Mohamed S El-Aasser p 712, respectively.</p>

<p>Miniemulsion polymerisation is well known in the art and the term "miniemulsion polymerisation" as used herein means the same as the term known in the art. Numerous scientific reviews of miniemulsion techniques have been published: 1) El Aasser, M.S., Miller, C.M., "Preparation of latexes using miniemulsions", In: Asua, J.M., editor. Polymeric dispersions. Principles and applications. Dordrecht: Kluwer, p. 109-126 (1997) 2) Sudol, E.D., El Aasser, M.S. , "Miniemulsion polymerisation", In: Lovell, P.A., El Aasser, M.S., editors. Emulsion polymerisation and emulsion polymers.</p>

<p>Chichester: Wiley, p. 699-722 (1997) 3) Asua, J.M., Prog. Polym. Sci., 27, 1283-1346 (2002) Miniemulsions generally lie in between macroemulsion and microemulsions in terms of droplet size and emulsion - 19 -stability. Miniemulsion droplets typically range in size from 50 to 500 nm. The emulsion can be stable for as little as a few days or for as long as a month. The droplets may be stabilised by the addition of an ionic surfactant (e.g. sodium lauryl sulphate) and a cosurfactant. The latter usually consists of either a long chain alkane (e.g. hexadecane) or an alcohol (e.g. hexadecanol). The function of the cosurfactant is twofold; it acts in combination with the surfactant to create a barrier to droplet/droplet coalescence by arranging at the oil-water interface and it also limits diffusion of the oil phase from smaller to larger droplets by virtue of its low water solubility.</p>

<p>Miniemulsions are typically formed by subjecting an oil (monomer), water, surfactant and cosurfactant system to high shear fields created by devices such as ultrasonifiers, homogenisers and microfluidisers. These devices rely on mechanical shear and/or cavitation to break the oil phase into submicron size droplets. When monomer is used as the oil phase, free radical polymerisation can subsequently be carried out by the addition of an initiator (e.g. ainmonium persuiphate). Such a process in which the miniemulsion droplets are converted to polymer particles is referred to as miniemulsion polymerisation. For the sake of clarity, by "miniemulsion droplet or emulsion droplet" as used herein is meant the miniemulsion droplet before it is polymerised, and "miniemulsion particles" or "emulsion particles" mean the polymerised miniemulsion droplets.</p>

<p>In conventional emulsion polymerisation the monomer diffuses through the aqueous phase to the surfactant formed micelles.</p>

<p>-20 -Particle nucleation begins and proceeds in these micelles and the monomer droplets merely act as a reservoir of monomer. Whereas in miniemulsion polymerisation the presence of cosurfactant and the use of high shear results in the formation of small monomer droplets. These droplets are polymerised directly and no monomer diffusion to micelles occurs and no particle formation occurs within micelles. Such differences are well documented in the literature for example in "Emulsion Polymerisation and Emulsion Polymers", Edited by P.A. Lovell and M.S. El-Aasser, John Wiley and Sons, Chapter 20, page 700-703.</p>

<p>In conventional emulsion polymerisation, the benefit agent can only be incorporated at relatively low levels (typically 10 % or less by weight of the particle) and must be sparingly water soluble, have low molecular weight (typically under 1,000 g mol') and have similar water solubility and diffusion rate as the monomer. However, for the miniemulsion polymerisation, none of these restraints apply. This allows the incorporation of higher levels (typically from 10 to 90 %) and a wider variety of benefit agents, such as completely water insoluble benefit agents (e.g. sugar polyesters, silicone resins and thermoplastic elastomers), in polymer particles, which cannot be achieved using conventional emulsion polymerisation techniques.</p>

<p>Furthermore, inorganic particles can also be incorporated into the polymer using miniemulsion, which cannot be achieved using conventional emulsion.</p>

<p>-21 -The preferred "hybridt' process comprises the steps of: (a) preparation of a miniemulsion (comprising monomers, a benefit agent, aperfume and a cosurfactant), and (b) polymerisation of the miniemulsion of step (a) to form miniemulsion core particles, and attachment of a deposition aid around the core particles.</p>

<p>A core-shell particle may be prepared by using the hybrid process as follows: (a) preparation of a miniemulsion (comprising monomers, a benefit agent, a perfume and a cosurfactant), and (b) polymerisation of the miniemulsion of step (a) to form miniemulsion core particles, and (c) addition of shell monomers and initiator such that polymerisation occurs to form a shell around the core particles of step (b) and attachment of a deposition aid around the particles.</p>

<p>Step (a) of either of the above 2 processes may consist of the following sub-steps: (i) mixing monomers, perfume and benefit agent with a cosurfactant to form a mixture (y), (ii) dissolving at least one surfactant in water to form a solution (z), (iii) combining (y) and (z) and subjecting to high shear to form a miniemulsion.</p>

<p>Step (iii) may consist of the following sub-steps: -22 - (1) (y) and (z) are combined and subjected to high shear to form an emulsion, (2) the emulsion of step (1) is then subjected to further shear (such as sonication or other suitable high pressure homogeniser such as a Microfluidiser or a Manton Gaulin homogeniser) to form a miniemulsion.</p>

<p>By mixed is meant mixed or dissolved, depending on the physical state of the benefit agent and/or perfume.</p>

<p>Preferably, an initiator is added to the miniemulsion of step (iii) or step (2) such that polymerisation of the monomers proceeds. Alternatively, the initiator can be added during step (a), for example if an initiator that is soluble in the monomer is used, or in step (b), for example if the initiator is water soluble.</p>

<p>Alternatively, the surfactant of step (ii) may be a reactive surfactant, by which is meant that it comprises groups that may participate in the polymerisation and a hydrophilic group. In this case it will be combined with the monomer in step (i).</p>

<p>The deposition aid is preferably added prior to addition of the initiator.</p>

<p>The preferred "artificial" process comprises the steps of: (a) preparation of a miniemulsion (comprising a polymer, a benefit agent, a perfume, a cosurfactant and a water insoluble volatile solvent), (b) removal of the volatile solvent, and -23 - (c) addition of shell monomers and subsequent polymerisation to form a shell around the core particles of step (b), wherein attachment of a deposition aid to the particles occurs in step (c) Step (a) may consist of the following sub-steps: (i) dissolving polymer, a benefit agent and a perfume with a cosurfactant in a water insoluble volatile solvent to form a mixture solution (m), (ii) dissolving at least one surfactant in water to form a mixture (n), and (iii) combining (m) and (n) and subjecting to high shear to form a miniemulsion.</p>

<p>A suitable solvent is dicholormethafle (DCM).</p>

<p>The resulting polymer particles preferably have a particle size of less than 1 micron, more preferably of less than 500 nm.</p>

<p>High shear as used herein is applied using any suitable apparatus such as an ultrasound sonicator, microfluidizer or homogenizer. High shear as used in step (iv) above is defined as shear of sufficiently high intensity that the emulsion of step (iii) above is reduced in particle size to sub-micron dimensions, preferably under 500 nm. Suitably, the emulsion of step (iv) is formed using a high shear homogeniser at 10,000 to 24,000 rpm for approximately 30 seconds to 5 minutes and then sonified using a probe ultrasound sonicator (at maximum power output) for 10 minutes to generate the miniemulsion. A suitable -24 -homogeniser is a Manton Gaulin homogeniser or any other make of high shear homogenizer such as an Ultra Turrax.</p>

<p>Cosurfactants, Initiators and Chain Transfer Agents The monomer (hybrid process) or polymer solution (artificial process) is mixed with a cosurfactant. Suitable cosurfactants for use in the present invention include hexadecane, cetyl alcohol, lauroyl peroxide, n-dodecyl mercaptan, dodecyl methacrylate, stearyl methacrylate, polystyrene and polyrnethyl methacrylate. The preferred cosurfactant comprises hexadecane.</p>

<p>The cosurfactant could be the benefit agent itself, if it is suitably hydrophobic.</p>

<p>Initiators and chain transfer agents may also be present.</p>

<p>Those skilled in the art will recognise that a chemical initiator will generally be required but that there are instances in which alternative forms of initiation will be possible, e.g. ultrasonic initiation or initiation by irradiation.</p>

<p>The initiator is preferably a chemical or chemicals capable of forming free radicals. Typically, free radicals can be formed either by homolytic scission (i.e. homolysis) of a single bond or by single electron transfer to or from an ion or molecule (e.g. redox reactions).</p>

<p>Suitably, in context of the invention, homolysis may be achieved by the application of heat (typically in the range of from 50 to 100 C). Some examples of suitable initiators -25 -in this class are those possessing peroxide (-0-0-) or azo (-N=N-) groups, such as benzoyl peroxide, t-butyl peroxide, hydrogen peroxide, azobisisobutyronitrile and ammonium persuiphate. Homolysis may also be achieved by the action of radiation (usually ultraviolet), in which case it is termed photolysis. Examples are the dissociation of 2,2'-azobis (2-cyanopropane) and the formation of free radicals from benzophenone and benzoin.</p>

<p>Redox reactions can also be used to generate free radicals.</p>

<p>In this case an oxidising agent is paired with a reducing agent which then undergo a redox reaction. Some examples of appropriate pairs in the context of the invention are ammonium persulphate/sodium metabisulphite, cumyl hydroperoxide/ferrous ion and hydrogen peroxide/ascorbic acid.</p>

<p>Preferred initiators are selected from the following: Homolytic: benzoyl peroxide, t-butyl peroxide, hydrogen peroxide, azobisisobutyronitrile, ammonium persulphate, 2,2' -azobis (cyanopropane), benzophenone, benzoin, Redox: ammonium persulphate/sodium metabisulphite mixture, cumyl hydroperoxide/ferrous ion mixture and/or hydrogen peroxide/ascorbic acid mixture. Preferred initiators are arnmonium persulphate and hydrogen peroxide/ascorbic acid mixture. The preferred level of initiator is in the range of from 0.1 to 5.0 % w/w by weight of monomer, more preferably, the level is in the range of from 1.0 to 3.0 % w/w by weight of monomer.</p>

<p>-26 -Where the benefit agent is SPE, the preferred initiator is ammonium persulphate and the aqueous phase is buffered with sodium bicarbonate.</p>

<p>Chain transfer agents can optionally be used to reduce the degree of polyinerisation and hence the final molecular weight of the polymer. A chain transfer agent contains very labile hydrogen atoms that are easily abstracted by a propagating polymer chain. This terminates the polymerisation of the growing polymer, but generates a new reactive site on the chain transfer agent that can then proceed to initiate further polymerisation of the remaining monomer. Chain transfer agents in the context of the invention typically contain thiol (mercaptan) functionality and can be represented by the general chemical formula RS-H, such as n-dodecyl mercaptan and 2-mercaptoethanol.</p>

<p>Preferred chain transfer agents are monothioglycerol and n-dodecyl mercaptan, used at levels of, preferably from 0 to 5 % w/w based on the weight of the monomer and more preferably at a level of 0.25 % w/w based on the weight of the monomer.</p>

<p>Laundry Treatment Compositions The polymer particles of the invention may be incorporated into laundry compositions.</p>

<p>The polymer particles are typically included in said compositions at levels of from 0.001% to 10%, preferably from 0.005% to 5%, most preferably from 0.01% to 3% by weight of the total composition.</p>

<p>-27 -The active ingredient in the compositions is preferably a surface active agent or a fabric conditioning agent. More than one active ingredient may be included. For some applications a mixture of active ingredients may be used.</p>

<p>The compositions of the invention may be in any physical form e.g. a solid such as a powder or granules, a tablet, a solid bar, a paste, gel or liquid, especially, an aqueous based liquid. In particular the compositions may be used in laundry compositions, especially in liquid, powder or tablet laundry composition.</p>

<p>The compositions of the present invention are preferably laundry compositions, especially main wash (fabric washing) compositions or rinse-added softening compositions. The main wash compositions may include a fabric softening agent and the rinse-added fabric softening compositions may include surface-active compounds, particularly non-ionic surface-active compounds.</p>

<p>The detergent compositions of the invention may contain a surface-active compound (surfactant) which may be chosen from soap and non-soap anionic, cationic, non-ionic, amphoteric and zwitterionic surface-active compounds and mixtures thereof. Many suitable surface-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch.</p>

<p>-28 -The preferred detergent-active compounds that can be used are soaps and synthetic non-soap anionic, and non-ionic compounds.</p>

<p>The compositions of the invention may contain linear alkylbenzene suiphonate, particularly linear alkylbenzene sulphonates having an alkyl chain length of from C8 to C15.</p>

<p>It is preferred if the level of linear alkylbenzene sulphonate is from 0 wt% to 30 wt%, more preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%, by weight of the total composition.</p>

<p>The compositions of the invention may contain other anionic surfactants in amounts additional to the percentages quoted above. Suitable anionic surfactants are well-known to those skilled in the art. Examples include primary and secondary alkyl sulphates, particularly C8 to C15 primary alkyl suiphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl suiphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.</p>

<p>The compositions of the invention may also contain non-ionic surfactant. Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C8 to C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the dO to C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to moles of ethylene oxide per mole of alcohol.</p>

<p>Non-ethoxylated nonionic surfactants include -29 -alkylpolyglycOsides, glycerol monoethers, and polyhydroxyamides (glucamide).</p>

<p>It is preferred if the level of non-ionic surfactant is from 0 wt% to 30 wt%, preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%, by weight of the total composition.</p>

<p>Any conventional fabric conditioning agent may be used in the compositions of the present invention. The conditioning agents may be cationic or non-ionic. If the fabric conditioning compound is to be employed in a main wash detergent composition the compound will typically be non-ionic. For use in the rinse phase, typically they will be cationic. They may for example be used in amounts from 0.5% to 35%, preferably from 1% to 30% more preferably from 3% to 25% by weight of the composition.</p>

<p>Suitable cationic fabric softening compounds are substantially water-insoluble quaternary ammonium materials comprising a single alkyl or alkenyl long chain having an average chain length greater than or equal to C20 or, more preferably, compounds comprising a polar head group and two alkyl or alkenyl chains having an average chain length greater than or equal to C14. Preferably the fabric softening compounds have two long chain alkyl or alkenyl chains each having an average chain length greater than or equal to C16. Most preferably at least 50% of the long chain alkyl or alkenyl groups have a chain length of C18 or above. It is preferred if the long chain alkyl or alkenyl -30 -groups of the fabric softening compound are predominantly linear.</p>

<p>Quaternary ainmonium compounds having two long-chain aliphatic groups, for example, distearyldimethyl ammonium chloride and di (hardened tallow alkyl) dimethyl ainmonium chloride, are widely used in commercially available rinse conditioner compositions. Other examples of these cationic compounds are to be found in "Surfactants Science Series" volume 34 ed. Richmond 1990, volume 37 ed. Rubingh 1991 and volume 53 eds. Cross and Singer 1994, Marcel Dekker Inc. New York".</p>

<p>Any of the conventional types of such compounds may be used in the compositions of the present invention.</p>

<p>The fabric softening compounds are preferably compounds that provide excellent softening, and are characterised by a chain melting Lf3 to La transition temperature greater than 250 C, preferably greater than 350 C, most preferably greater than 450 C. This L13 to La transition can be measured by differential scanning calorimetry as defined in "Handbook of Lipid Bilayers", D Marsh, CRC Press, Boca Raton, Florida, 1990 (pages 137 and 337) Substantially water-insoluble fabric softening compounds are defined as fabric softening compounds having a solubility of less than 1 x i0 wt % in demineraljsed water at 20 C.</p>

<p>Preferably the fabric softening compounds have a solubility of less than 1 x 10 wt%, more preferably from less than 1 x 10-8 to 1 x 10_6 wt%.</p>

<p>-31 -Especially preferred are cationic fabric softening compounds that are water-insoluble quaternary ammonium materials having two C12-22 alkyl or alkenyl groups connected to the molecule via at least one ester link, preferably two ester links. An especially preferred ester-linked quaternary ammonium material can be represented by the formula: R5 R5 R7-T-R6 (CH2) p-T-R6 wherein each R5 group is independently selected from C1-4 alkyl or hydroxyalkyl groups or C2-4 alkenyl groups; each R6 group is independently selected from C8-28 alkyl or alkenyl groups; and wherein R7 is a linear or branched alkylene group of 1 to 5 carbon atoms, T is or 0C and p is 0 or is an integer from 1 to 5.</p>

<p>Di(tallowoxyloXyethyl) dimethyl arninonium chloride and/or its hardened tallow analogue is an especially preferred compound of this formula.</p>

<p>A second preferred type of quaternary arnmonium material can be represented by the formula:</p>

<p>--</p>

<p>-32 -OOC R6 (R5)3N±(CH2)p CH CH200CR6 wherein R5, p and R6 are as defined above.</p>

<p>A third preferred type of quaternary ammonium material are those derived from triethanolamine (hereinafter referred to as TEA quats') as described in for example US 3915867 and represented by formula: (TOCI-i2CH2) 3N+ (R9) wherein T is H or (R8-CO-) where R8 group is independently selected from C8-28 alkyl or alkenyl groups and R9 is C1-4 alkyl or hydroxyalkyl groups or C2-4 alkenyl groups. For example N-methyl-N,N,N-triethanolamjne ditallowester or di-hardened-tallowester quaternary ammonium chloride or methosuiphate. Examples of commercially available TEA quats include Rewoquat WE18 and Rewoquat WE2O, both partially unsaturated (ex. WITCO), Tetranyl AOT-1, fully saturated (ex. KAO) and Stepantex VP 85, fully saturated (ex. Stepan).</p>

<p>It is advantageous if the quaternary ammonium material is biologically biodegradable.</p>

<p>Preferred materials of this class such as 1,2-bis(hardened tallowoyloxy)-3-trimethylamrnonjum propane chloride and their methods of preparation are, for example, described in US 4 137 180 (Lever Brothers Co). Preferably these -33 -materials comprise small amounts of the corresponding monoester as described in US 4 137 180, for example, 1-hardened tallowoyloxy-2-hydroxy-3-trimethylainmonium propane chloride.</p>

<p>Other useful cationic softening agents are alkyl pyridinium salts and substituted imidazoline species. Also useful are primary, secondary and tertiary amines and the condensation products of fatty acids with alkylpolyamines.</p>

<p>The compositions may alternatively or additionally contain water-soluble cationic fabric softeners, as described in GB 2 039 556B (Unilever).</p>

<p>The compositions may comprise a cationic fabric softening compound and an oil, for example as disclosed in EP-A-0 82 953 1.</p>

<p>The compositions may alternatively or additionally contain nonionic fabric softening agents such as lanolin and derivatives thereof.</p>

<p>Lecithins and other phospholipids are also suitable softening compounds.</p>

<p>In fabric softening compositions nonionic stabilising agent may be present. Suitable nonionic stabilising agents may be present such as linear C8 to C22 alcohols alkoxylated with to 20 moles of alkylene oxide, ClO to C20 alcohols, or -34 -mixtures thereof. Other stabilising agents include the deflocculating polymers as described in EP 0415698A2 and EP 0458599B1.</p>

<p>Advantageously the nonionic stabilising agent is a linear C8 to C22 alcohol alkoxylated with 10 to 20 moles of alkylene oxide. Preferably, the level of nonionic stabiliser is within the range from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight, most preferably from 1 to 4% by weight. The mole ratio of the quaternary arnmoniuin compound and/or other cationic softening agent to the nonionic stabilising agent is suitably within the range from 40:1 to about 1:1, preferably within the range from 18:1 to about 3:1.</p>

<p>The composition can also contain fatty acids, for example C8 to C24 alkyl or alkenyl monocarboxylic acids or polymers thereof. Preferably saturated fatty acids are used, in particular, hardened tallow C16 to C18 fatty acids.</p>

<p>Preferably the fatty acid is non-saponified, more preferably the fatty acid is free, for example oleic acid, lauric acid or tallow fatty acid. The level of fatty acid material is preferably more than 0.1% by weight, more preferably more than 0.2% by weight. Concentrated compositions may comprise from 0.5 to 20% by weight of fatty acid, more preferably 1% to 10% by weight. The weight ratio of quaternary ammonium material or other cationic softening agent to fatty acid material is preferably from 10:1 to 1:10.</p>

<p>It is also possible to include certain mono-alkyl cationic surfactants which can be used in main-wash compositions for -35 -fabrics. Cationic surfactants that may be used include quaternary ainmonium salts of the general formula R1R2R3R4N+ X-wherein the R groups are long or short hydrocarbon chains, typically alkyl, hydroxyalkyl or ethoxylated alkyl groups, and X is a counter-ion (for example, compounds in which Ri is a C8-C22 alkyl group, preferably a C8-C1O or C12-C14 alkyl group, R2 is a methyl group, and R3 and R4, which may be the same or different, are methyl or hydroxyethyl groups); and cationic esters (for example, choline esters) The choice of surface-active compound (surfactant), and the amount present, will depend on the intended use of the detergent composition. In fabric washing compositions, different surfactant systems may be chosen, as is well known to the skilled formulator, for handwashing products and for products intended for use in different types of washing machine.</p>

<p>The total amount of surfactant present will also depend on the intended end use and may be as high as 60 wt%, for example, in a composition for washing fabrics by hand. In compositions for machine washing of fabrics, an amount of from 5 to 40 wt% is generally appropriate. Typically the compositions will comprise at least 2 wt% surfactant e.g. 2- 60%, preferably 15-40% most preferably 25-35%, by weight of the composition.</p>

<p>Detergent compositions suitable for use in most automatic fabric washing machines generally contain anionic non-soap -j -36 -surfactant, or non-ionic surfactant, or combinations of the two in any suitable ratio, optionally together with soap.</p>

<p>The compositions of the invention, when used as main wash fabric washing compositions, will generally also contain one or more detergency builders. The total amount of detergency builder in the compositions will typically range from 5 to wt%, preferably from 10 to 60 wt%, by weight of the compositions.</p>

<p>Inorganic builders that may be present include sodium carbonate, if desired in combination with a crystallisation seed for calcium carbonate, as disclosed in GB 1 437 950 (Unilever); crystalline and amorphous aluminosilicates, for example, zeolites as disclosed in GB 1 473 201 (Henkel), amorphous aluminosilicates as disclosed in GB 1 473 202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter & Gamble); and layered silicates as disclosed in EP 164 514B (Hoechst). Inorganic phosphate builders, for example, sodium orthophosphate, pyrophosphate and tripolyphosphate are also suitable for use with this invention.</p>

<p>The compositions of the invention preferably contain an alkali metal, preferably sodium, aluminosilicate builder.</p>

<p>Sodium aluminosilicates may generally be incorporated in amounts of from 10 to 70% by weight (anhydrous basis), preferably from 25 to 50 wt%.</p>

<p>-37 -The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula: 0.8-1.5 Na20. A1203. 0.8-6 S102 These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5-3.5 Si02 units (in the formula above). Both the amorphous and the crystalline materials can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1 429 143 (Procter & Gamble). The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A and X, and mixtures thereof.</p>

<p>The zeolite may be the commercially available zeolite 4A now widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, the zeolite builder incorporated in the compositions of the invention is maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070A (Unilever). Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium weight ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20.</p>

<p>Especially preferred is zeolite MAP having a silicon to aluminium weight ratio not exceeding 1.07, more preferably -38 -about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per g of anhydrous material.</p>

<p>Organic builders that may be present include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di and trisuccinates, carboxymethyloxy succinates, carboxymethyloxylflalOflateS, dipicolinates, hydroxyethylimiflOdiacetates, alkyl-and alkenylmalonateS and succinates; and sulphonated fatty acid salts. This list is not intended to be exhaustive.</p>

<p>Especially preferred organic builders are citrates, suitably used in amounts of from 5 to 30 wt%, preferably from 10 to wt%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt%, preferably from 1 to 10 wt%.</p>

<p>Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.</p>

<p>Compositions according to the invention may also suitably contain a bleach system. Fabric washing compositions may desirably contain peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution.</p>

<p>Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, n / -39 -persilicates and persuiphates. Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate.</p>

<p>Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture.</p>

<p>Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao).</p>

<p>The peroxy bleach compound is suitably present in an amount of from 0.1 to 35 wt%, preferably from 0.5 to 25 wt%. The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 0.1 to 8 wt%, preferably from 0.5 to 5 wt%.</p>

<p>Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and pernoanoic acid precursors. Especially preferred bleach precursors suitable for use in the present invention are N,N,N' ,N' , -tetracetyl ethylenediamine (TAED) and sodium nonanoyloxybenzene sulphonate (SNOBS). The novel quaternary ainmonium and phosphonium bleach precursors disclosed in US 4 751 015 and US 4 818 426 (Lever Brothers Company) and EP 402 971A (Unilever), and the cationic bleach precursors disclosed in EP 284 292A and EP 303 520A (Kao) are also of interest.</p>

<p>-40 -The bleach system can be either supplemented with or replaced by a peroxyacid. Examples of such peracids can be found in US 4 686 063 and US 5 397 501 (Unilever). A preferred example is the imido peroxycarboxylic class of peracids described in EP A 325 288, EP A 349 940, DE 382 3172 and EP 325 289. A particularly preferred example is phthalimido peroxy caproic acid (PAP). Such peracids are suitably present at 0.1 -12%, preferably 0.5 -10%.</p>

<p>A bleach stabiliser (transition metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetra- acetate (EDTA), the polyphosphonates such as Dequest (Trade Mark) and non-phosphate stabilisers such as EDDS (ethylene diamine di-succinic acid). These bleach stabilisers are also useful for stain removal especially in products containing low levels of bleaching species or no bleaching species.</p>

<p>An especially preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate optionally together with a bleach activator), and a transition metal bleach catalyst as described and claimed in EP 458 397A, EP 458 398A and EP 509 787A (Unilever) The compositions according to the invention may also contain one or more enzyme(s).</p>

<p>Suitable enzymes include the proteases, amylases, cellulases, oxidases, peroxidases and lipases usable for incorporation in detergent compositions. Preferred proteolytic enzymes (proteases) are, catalytically active -41 -protein materials which degrade or alter protein types of stains when present as in fabric stains in a hydrolysis reaction. They may be of any suitable origin, such as vegetable, animal, bacterial or yeast origin.</p>

<p>Proteolytic enzymes or proteases of various qualities and origins and having activity in various pH ranges of from 4-12 are available and can be used in the instant invention.</p>

<p>Examples of suitable proteolytic enzymes are the subtilisins which are obtained from particular strains of B. Subtilis B. licheniformis, such as the commercially available subtilisins Maxatase (Trade Mark), as supplied by Genencor International N.y., Delft, Holland, and Alcalase (Trade Mark), as supplied by Novozymes Industri A/S, Copenhagen, Denmark.</p> <p>Particularly suitable is a protease obtained from a strain of Bacillus

having maximum activity throughout the pH range of 8-12, being commercially available, e.g. from Novozymes Industri A/S under the registered trade-names Esperase (Trade Mark) and Savinase (Trade-Mark). The preparation of these and analogous enzymes is described in GB 1 243 785.</p>

<p>Other commercial proteases are Kazusase (Trade Mark obtainable from Showa-Denko of Japan), Optimase (Trade Mark from Miles Kali-Chemie, Hannover, West Germany), and Superase (Trade Mark obtainable from Pfizer of U.S.A.).</p>

<p>Detergency enzymes are commonly employed in granular form in amounts of from about 0.1 to about 3.0 wt%. However, any suitable physical form of enzyme may be used. Th</p>

<p>-42 -The compositions of the invention may contain alkali metal, preferably sodium carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in amounts ranging from 1 to 60 wt%, preferably from 2 to 40 wt%. However, compositions containing little or no sodium carbonate are also within the scope of the invention.</p>

<p>Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate copolymer, or sodium silicate. One preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt%.</p>

<p>Other materials that may be present in detergent compositions of the invention include sodium silicate; antiredeposition agents such as cellulosic polymers; soil release polymers; inorganic salts such as sodium sulphate; or lather boosters as appropriate; proteolytic and lipolytic enzymes; dyes; coloured speckles; fluorescers and decoupling polymers. This list is not intended to be exhaustive.</p>

<p>However, many of these ingredients will be better delivered as benefit agent groups in materials produced according to the first aspect of the invention.</p>

<p>The detergent composition when diluted in the wash liquor (during a typical wash cycle) will typically give a pH of the wash liquor from 7 to 10.5 for a main wash detergent.</p>

<p>Particulate detergent compositions are suitably prepared by spray-drying a slurry of compatible heat-insensitive -43 -ingredients, and then spraying on or post-dosing those ingredients unsuitable for processing via the slurry. The skilled detergent formulator will have no difficulty in deciding which ingredients should be included in the slurry and which should not.</p>

<p>Particulate detergent compositions of the invention preferably have a bulk density of at least 400 g/litre, more preferably at least 500 g/litre. Especially preferred compositions have bulk densities of at least 650 g/litre, more preferably at least 700 g/litre.</p>

<p>Such powders may be prepared either by post-tower densification of spray-dried powder, or by wholly non-tower methods such as dry mixing and granulation; in both cases a high-speed mixer/granulator may advantageously be used.</p>

<p>Processes using high-speed mixer/granulators are disclosed, for example, in EP 340 013A, EP 367 339A, EP 390 251A and EP 420 317A (Unilever).</p>

<p>Liquid detergent compositions can be prepared by admixing the essential and optional ingredients thereof in any desired order to provide compositions containing components in the requisite concentrations. Liquid compositions according to the present invention can also be in compact form which means it will contain a lower level of water compared to a conventional liquid detergent.</p>

<p>-44 -Product Forms The composition of the invention may be in the form of a liquid, solid (e.g. powder or tablet), a gel or paste, spray, stick, bar or a foam or mousse. Examples include a soaking product, a rinse treatment (e.g. conditioner or finisher) or a main-wash product. Compositions suitable for direct application are preferred, such as gel or paste, spray, stick, bar, foam or mousse. The means for manufacturing any of the product forms are well known in the art. If the polymer particles are to be incorporated in a powder (optionally the powder to be tableted), and whether or not pre-emulsified, they are optionally included in a separate granular component.</p>

<p>Substrate When used in laundering, the substrate may be any substrate onto which it is desirable to deposit polymer particles and which is subjected to treatment such as a washing or rinsing process.</p>

<p>In particular, the substrate may be a textile fabric.</p>

<p>Treatment The treatment of the substrate with the material of the invention can be made by any suitable method such as washing, soaking or rinsing of the substrate but preferably by direct application such as spraying, rubbing, spotting, smearing, etc. -45 -The treatment may involve contacting the substrate with an aqueous medium comprising the material of the invention.</p>

<p>The treatment may be provided as a spray composition e.g., for domestic (or industrial) application to fabric in a treatment separate from a conventional domestic laundering process. Suitable spray dispensing devices are disclosed in WO 96/15310 (Procter & Gamble) and are incorporated herein by reference. Alternatively, the composition may be applied through the irons water tank, a separate reservoir or a spray cartridge in an iron, as described in EP 1201816 and Wa 99/27176.</p>

<p>EXAMPLES</p>

<p>Embodiments of the present invention will now be explained in more detail by reference to the following non-limiting</p>

<p>examples: -</p>

<p>In the following examples where percentages are mentioned, this is to be understood as percentage by weight unless otherwise stated.</p>

<p>The following abbreviations are used:-SDS -Sodium Dodecyl Sulphate THF -Tetrahydrofuran SPE -sugar polyester DCM -Dichioromethane MWL -Model wash liquor -46 -Example 1 -preparation of a model perfume and a model wash liquor A simple model perfume was prepared and used in the ensuing examples. The model perfume components were selected on the following bases: - 1) the component formed middle or base notes, and 2) the component was readily commercially available.</p>

<p>The components thus selected are shown in Table 1.</p>

<p>Table 1 -Perfume components used to make a simple model perfume.</p>

<p>Component Aldrich Formula FW b.p Catalog ( C) ue Code a,a-Dimethyl phenethyl W239208 C12H1602 192 250 at acetate (DMPEA) atmos P Methyl Dihydro Jasmonate W340804 C13H2203 226 110 at (MDHJ) 0.2 rnmHg Phenethyl Phenylacetate W286605 C16H1602 325 325 at (PEPA) atmos P The composition of the model perfume is shown in Table 2.</p>

<p>-47 -Table 2 -Composition of the simple model perfume.</p>

<p>Component Mass (g) wt % a,a-Dimethyl phenethyl 7.8644 33.18 acetate (DMPEA) Methyl Dihydro Jasmonate 7.9347 33.26 (MDHJ) Phenethyl Phenylacetate 7.8445 33.55 (PEPA) Preparation of a model wash liquor: A standard model wash liquor was prepared for use in the ensuing examples as follows: First, a buffer stock solution was made up with the following composition: Trisodium citrate at O.175g/l, sodium citrate at 0.29g1l, sodium bicarbonate at 0.05g/l and sodium sulphate at 1.lg/l.</p>

<p>A surfactant stock solution was also prepared which had the following composition: Anionic surfactant: Linear Alkyl Sulphate (LAS) at 0.5g/l active and nonionic surfactant: (Synperonic A7 or Neodol 25- 7E0) at 0.5g/l active.</p>

<p>-48 -The two stock solutions were then mixed together at a 50:50 ratio to produce a liquor of lg/l surfactant of about pH 10.5.</p>

<p>Example 2 -Preparation of particles P1 and P2 by hybrid miniemulsion Particles according to the invention were prepared by the hybrid miniemulsion route as follows: First, stock solutions were prepared as follows: 1. A stock surfactant solution was prepared by dissolving SDS (2.5 g) and Synperonic A7 (10 g) in demineralised water (500 ml) 2. An LBG stock solution was prepared by slowly dissolving LBG (5 g) in hot water (500 ml) with continuous stirring. (This stock solution was kept refrigerated once made.) 3. A monomer/SPE/model perfume solution was prepared by dissolving SPE (ER290) (25 g) in butyl methacrylate (25 g), adding model perfume (5 g) and then adding hexadecane (2 g).</p>

<p>Particles (P1) comprising a core (polymer/benefit agent (SPE)/model perfume) and a deposition aid (LEG) were then prepared using the stock solutions and the hybrid miniemulsion method: 1. Surfactant stock solution (50 ml) was mixed with demineralised water (370 ml) -49 - 2. To the above mixture 50 g of the monomer/SPE/model perfume solution was added with mixing with an Ultratorax mixer at 20,000 rpm for 5 minutes, resulting in a crude emulsion.</p>

<p>3. Using a sonic probe the crude emulsion was then ultrasonicated at full power for 10 minutes, with stirring provided by a stirrer hot plate and stirrer flea in the crude emulsion. This resulted in the formation of miniemulsion droplets.</p>

<p>4. The miniemulsion droplets and 1% LBG solution (50 ml) were placed in a suitable vessel, such as a polymerisation kettle, equipped with an over head stirrer, condenser, temperature controlled oil bath and a thermo-couple and heated until the mixture reached 75 C.</p>

<p>5. Once the mixture reached the desired temperature the initiation system was added, namely sodium bicarbonate (0.5 g) in water (10 ml) plus airiinonium persulphate (0.5 g) in water (10 ml) 6. The reaction was allowed to finish before being allowed to cool down and extra surfactant Tween 80 (2 g) in water (10 ml) added to help stabilise the latex.</p>

<p>Particles (P2) comprising a core (polymer/benefit agent (SPE)/model perfume), a shell and a deposition aid (LBG) were also prepared using the stock solutions and the hybrid miniemulsion method: 1. Surfactant stock solution (50 ml) was mixed with demineralised water (370 ml) -50 - 2. To the above mixture 50 g of the monomer/SPE/model perfume solution was added with mixing with an Ultratorax mixer at 20,000 rpm for 5 minutes, resulting in a crude emulsion.</p>

<p>3. Using a sonic probe the crude emulsion was then ultrasonicated at full power for 10 minutes, with stirring provided by a stirrer hot plate and stirrer flea in the crude emulsion. This resulted in the formation of miniemulsion droplets.</p>

<p>4. The miniemulsion droplets were placed in a suitable vessel, such as a polymerisation kettle, equipped with an over head stirrer, condenser, temperature controlled oil bath and a thermo-couple and heated until the mixture reached 75 C.</p>

<p>5. Once the mixture reached the desired temperature the initiation system was added, namely sodium bicarbonate (0.5 g) in water (10 ml) plus ammonium persuiphate (0.5 g) in water (10 ml).</p>

<p>6. 2.5 hours were allowed to elapse before vinyl acetate (25 g) and of 1% LBG solution (50 ml) were combined and allowed to mix for 30 minutes.</p>

<p>7. An initiator system of 35 wt % hydrogen peroxide (0.77 g) in water (5 ml) and ascorbic acid (0.25 g) in water (5 ml) was added.</p>

<p>8. Once the reaction had finished, the reaction mixture was allowed to cool down and extra surfactant (Tween 80 (2 g) in water (10 ml)) was added to help stabilise the latex.</p>

<p>-51 -Example 3 -Preparation of particles, P3, by artificial miniemuls ion Particles (P3) comprising a core (polymer/benefit agent (SPE)/model perfume), a shell and a deposition aid (LBG) were also prepared by the artificial miniemulsion route as follows: First, a solution of polymer/SPE/model perfume in dichloromethane (DCM) was prepared by dissolving SPE (ER290) (12.5 g) dissolved in poly butyl methacrylate (12.5 g), model perfume (2.5 g) and hexadecane (1 g) in DCM (100 ml).</p>

<p>Polymer/SPE/model perfume artificial minieinulsion latex particles were then prepared using the following method: 1. Surfactant stock solution (50 ml) was mixed with demineralised water (375 ml).</p>

<p>2. The polymer/SPE/model perfume/DCM solution (125 ml) was added to the surfactant/water mixture with mixing with an Ultratorax mixer at 20,000 rpm for 5 minutes to form a crude emulsion.</p>

<p>3. Using a sonic probe, the crude emulsion was ultrasonicated at full power for 10 minutes with stirring provided by a stirrer hot plate and stirrer flea in the crude emulsion to form miniemulsion droplets.</p>

<p>4. The miniemulsion droplets were then placed in a suitable round bottom flask and the DCM removed using a rotary evaporator and gravimetric analysis to monitor the loss of DCM.</p>

<p>-52 - 5. The miniemulsion droplets were then placed in a suitable vessel, such as a polymerisation kettle, equipped with an over head stirrer, condenser, temperature controlled oil bath and a thermo-couple and heated to 75 C.</p>

<p>6. 2.5 hours were then allowed to elapse before vinyl acetate (25 g) and of 1% LEG solution (50 ml) were then added and allowed to mix for 30 minutes.</p>

<p>7. An initiator system of 35 wt % hydrogen peroxide (0.77 g) in water (5 ml) and ascorbic acid (0.25 g) in water (5 ml) was added.</p>

<p>8. Once the reaction had finished, the reaction mixture was allowed to cool down and extra surfactant (Tween 80 (2 g) in water (10 ml)) was added to help stabilise the latex.</p>

<p>Preparation of Comparative Example A The model perfume was emulsified to form comparative example A. The emulsion was prepared in the following way: Synperonic A20 (0.1 g) and SDS (0.025 g) were dissolved in demineralised water (50 ml). Model perfume (0.5 g) was then added and the resulting mixture mixed with a high shear overhead mixer for 2 minutes.</p>

<p>The compositions of the particles P1, P2 and P3 and of comparative example A are summarised in Table 3 below.</p>

<p>Table 3 -Compositions of particles P1-P3 and of comparative</p>

<p>example A.</p>

<p>-53 -All the particles had a ratio of PBMA: SPE: Model Perfume of 50: 50: 10.</p>

<p>P1 P2 P3 A Method of Hybrid Hybrid Artificial Conventional preparation Emulsion Core composition monomer! BMA' BMA PBMA3 -polymer benefit SPE2 SPE SPE -agent model -perfume Shell -vinyl vinyl - composition acetate acetate Deposition LBG4 LBG LEG -aid BMA = Eutyl Methacrylate, Aldrich 2sp = Sugar Polyester, ER290, Mitsubishi 3PBMA = Poly Butyl Methacrylate, Aldrich 4LBG = Locust Bean Gum, Sigma 5Model perfume -as given in Table 2 Example 4 -Longevity of the model perfume on fabric The amount of perfume remaining on fabric which had been spotted with particles according to the invention (P1, P2, P3) or with the control emulsion A was determined as follows: -54 - 1. 100 p.1 of a 1:4 particle:water (i.e. 20 p.1 particle and p.1 water) mixture was then spotted onto the fabric using a glass capillary tube. The fabric was hung in an ambient atmosphere.</p>

<p>2. At time intervals of 1, 3 and 6 days, approximately 1 g of fabric was placed into a vial with 10 ml THF overnight and then removed from the vial.</p>

<p>3. The amount of each perfume component remaining on the fabric was then determined by GC/MS after 1, 3 and 6 days.</p>

<p>Table 4 -Amount of perfume remaining on fabric spotted with P1, P2, P3 or A after 1, 3 and 6 days.</p>

<p>Amount perfume remaining on fabric (%) Example Perfume Day 1 Day3 Day 6 component P1 DMPEA 3.68 2.95 2.98 MDHJ 94.84 70.19 62.03 PEPA 96.17 78.47 71.86 P2 DMPEA 5.23 4.13 3.96 MDHJ 80.58 57.58 51.56 PEPA 93.03 71.75 64.60 P3 DMPEA 3.71 3.81 3.77 MDHJ 82.12 67.67 61.75 PEPA 98.04 88.86 87.30 A DMPEA 1.84 1.65 1.77 MDHJ 69.68 55.02 51.79 PEPA 80. 65 73.33 80.70 -55 -As expected, DMPEA experienced the greatest loss as it was the most volatile component in the model perfume.</p>

<p>It will be seen that the particles according to the invention (P1, P2 and P3) give greater longevity of perfume on fabric than the comparative control.</p>

<p>Example 5 -Protection of perfume during wash in water and in model wash liquor (MWL) The amount of perfume retained in the particles (P1, P2, P3) or in the control A following washing in water or in a model wash liquor (MWL) was determined as follows: 1. 20 p1 of particles/emulsion containing 1 % perfume was added to 10 ml of water or Model Wash Liquor (MWL).</p>

<p>2. The resulting mixture was then agitated using a flask shaker for 1 hour.</p>

<p>3. 10 ml of hexane was then added and the mixture agitated further.</p>

<p>4. The hexane and aqueous layers were then allowed to separate.</p>

<p>5. The aqueous layer was then removed and discarded and the hexane solution dried over magnesium sulphate.</p>

<p>6. The level of perfume in the organic layer was then determined using GP/MS.</p>

<p>Table 5 -Amount of perfume retained in P1, P2, P3 or A after washing in water and MWL.</p>

<p>-56 -Amount model perfume retained in the particle (%)</p>

<p>Example water MWL</p>

<p>P1 38.0 13.0 P2 32.9 5.9 P3 49.7 34.9 A 19.1 0.2 In all cases, less perfume remains in the particle after exposure to MWL compared to water alone.</p>

<p>It will be seen that the particles according to the invention (P1, P2 and P3) give greater protection of perfume against surfactants than the control particle.</p>

<p>Example 6 -Deposition of perfume onto fabric from P1, P2 and A during washing.</p>

<p>Perfume was deposited onto fabric from particles (P1, P2) or the control A during washing by using the standard Linitest wash protocol as follows: (1) The Linitest was heated to 40 C.</p>

<p>(2) In a 550ml steel washpot, the required level of silicone emulsion was added and made up to a final volume of 150m1 with test liquor.</p>

<p>(3) 25 steel ball bearings were added.</p>

<p>(4) 1 piece of fabric weighing 18g was then added.</p>

<p>(5) The pots were sealed and placed in the cradle of the Linitest, and washed at 40 C for 45 minutes.</p>

<p>-57 - (6) At the end of the wash the pots were removed from the cradle and opened.</p>

<p>(7) As much wash liquor as possible was decanted off.</p>

<p>(8) 250m1s of water was added to the pot and resealed (9) Steps 7 & 8 were repeated for all pots.</p>

<p>(10) The pots were replaced in the Linitest and washed for minutes.</p>

<p>(11) Steps 6 -10 were repeated for all pots.</p>

<p>(12) At the end of the wash the pots were removed from the Linitest and step 7 repeated.</p>

<p>(13) The fabric was gently squeezed to remove any excess water.</p>

<p>(14) The samples were line dried overnight.</p>

<p>The liquor to cloth ratio was about 8: 1.</p>

<p>The amount of perfume deposited onto fabric from particles (P1, P2) or the control A during washing was then determined using GC/MS: Table 6 -Amount of perfume deposited onto fabric from P1, P2, P3 or A. Example Amount model perfume deposited onto fabric (%) P1 4.0 P2 4.6 A 3.2 -58 It will be seen that the particles according to the invention (P1 and P2) give greater deposition of perfume onto fabric than the control particle.</p>

Claims (1)

1. <p>S</p>

   <p>-59 -</p>

   <p>CLAIMS</p>

   <p>1. A polymer particle comprising a core wherein the core comprises a perfume, a benefit agent, and a polymer comprising monomer units which are derived from monomers selected from the group consisting of:-a) monomers with a solubility in water of less than 0.1 g/l, and/or b) monomers with a solubility in water of from 0.1 to g/l, and c) optionally, monomers with a solubility in water of greater than 30 g/l, and/or d) optionally, cross linkers, and wherein the particle further comprises a nonionic deposition aid.</p>

   <p>2. A particle as claimed in claim 1, wherein the deposition aid is a polysaccharide having 13-1,4 linkages.</p>

   <p>3. A particle as claimed in claim 2, wherein the polysaccharide is selected from the group consisting of a polymannan, a polyglucan, a polyglucomannan, a polyxyloglucan and a polygalactomannan or a mixture thereof.</p>

   <p>4. A particle as claimed in claim 3, wherein the polysaccharide is locust bean gum.</p>

   <p>-60 - 5. A particle as claimed in any preceding claim which further comprises a shell, wherein the shell comprises monomer units selected from b), and optionally c) and/or optionally d).</p>

   <p>6. A particle as claimed in any preceding claim wherein the benefit agent is selected from the group consisting of fabric softeners, conditioners, shape retention agents, anti-crease agents, ease of ironing aids, quick drying aids, lubricants, texturising agents, insecticides, insecticide repellents, fungicides, photofading inhibitors, dyes, pigments fluorescers and sunscreens, or mixtures thereof.</p>

   <p>7. A particle as claimed in claim 6, wherein the benefit agent is a chemical or mechanical protective agent.</p>

   <p>8. A particle as claimed in any preceding claim, wherein the benefit agent comprises a biodegradable lubricant.</p>

   <p>9. A particle as claimed in claim 8 wherein the lubricant is a sugar polyester.</p>

   <p>10. A particle as claimed in claim 9 wherein the sugar polyester is a sucrose polyester, preferably selected from sucrose tetrastearate, sucrose tetraerucate, sucrose tetralaurate, sucrose tetraoleate, sucrose tetrapalmitate and sucrose tetrapaim kernal.</p>

   <p>-61 - 11. A particle as claimed in claim 9 wherein the particle comprises from 0.1 to 99 %, preferably from 50 to 99 % of sugar polyester, by weight.</p>

   <p>12. A particle as claimed in any preceding claim wherein the perfume is present in an amount of from 1 to 50 % by total weight of the particle, preferably from 10 to % by total weight of the particle.</p>

   <p>13. A particle as claimed in any preceding claim wherein the perfume has a molecular weight of from 50 to 500.</p>

   <p>14. A particle as claimed in any preceding claim wherein the perfume has a boiling point of from 30 to 500 degrees Centigrade.</p>

   <p>15. A particle as claimed in any preceding claim wherein the polymer comprises monomer units which are derived from monomers selected from the group consisting of olefins, ethylene, vinylaromatic monomers, esters of vinyl alcohol with mono-and di-carboxylic acids, esters of a,113-monoethylenically unsaturated mono-and dicarboxylic acids with alcohols, nitriles of a,13-monoethylenically unsaturated carboxylic acids, conjugated dienes, a,3-monoethylenically unsaturated monocarboxylic and dicarboxylic acids and their amides, methacrylic acid and its esters with alcohols and diols, acrylic acid and its esters with alcohols and diols, dimethyl or di-n-butyl maleate, and/or vinyl-sulfonic acid and its water-soluble salts and mixtures thereof.</p>

   <p>-62 - 16. A particle as claimed in any preceding claim wherein the monomers a), b), c) and d) comprise the following:-a) vinyl octate; Vinyl decanote, vinyl laurate; vinyl stearate; esters of acrylic, methacrylic, maleic, fumaric or itaconic acid with decyl, dodecyl, tetadecyl, hexadecyl and octadecyl alcohol, b) styrene; -methylstyrene; o-chlorostyrene vinyl acetate; vinyl propionate; vinyl n-butyrate; esters of acrylic, methacrylic, maleic, fumaric or itaconic acid with methyl, ethyl, n-butyl, isobutyl, n-hexyl and 2-ethylhexyl alcohol; 1,3-butadiene; 2,3 dimethyl butadiene; and isoprene, c) acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, poly (alkylene oxide) monoacrylates and monomethacrylates, N-vinyl- pyrrolidone, methacrylic and acrylic acid, 2-hydroxyethyl acrylates and methacrylates, glycerol acrylates and methacrylates, poly(ethylene glycol) methacrylates and acrylates, n-vinyl pyrrolidone, acryloyl morpholine, vinyl formamide, n-vinyl acetamide and vinyl caprolactone, acrylonitrile, acrylamide, and methacrylamide at levels of less than 10 % by weight of the monomer unit content of the particle;

   2-(dimethylamino) ethyl methacrylate, 2-(diethylamino) ethyl methacrylate, 2-(tert-butylamino) ethyl methacrylate, 2 -aminoethyl methacrylate, 2-(2-oxo-1-imidazolidinyl) ethyl -63 -methacrylate, vinyl pyridine, vinyl carbazole, vinyl imidazole, vinyl aniline, and their cationic forms after treatment with alkyl halides, d) vinyltoluenes, divinyl benzene, ethylene glycol diacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylates, ethylene glycol dimethacrylate, 1,2-propylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, methylenebisacrylamide, cyclopentadienyl acrylate, and triallyl cyanurate.</p>

   <p>17. A particle as claimed in claim 16 wherein the polymer comprises monomer units, which are derived from monomers selected from the group consisting of butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, styrene, vinyl acetate and divinyl benzene, or mixtures thereof.</p>

   <p>18. A particle as claimed in any preceding claim, having a particle size of less than 1 micron, preferably of less than 500nm.</p>

   <p>-64 - 19. A process for the preparation of polymer particles as claimed in any preceding claim, which comprises preparation of a miniemulsion.</p>

   <p>20. A process as claimed in claim 19 which comprises the steps of: (a) preparation of a miniemulsion (comprising monomers, a benefit agent, a perfume and a cosurfactant), and (b) polymerisation of the miniemulsion of step (a) to form miniemulsion core particles, and (c) attachment of a deposition aid around the core particles of step (b).</p>

   <p>21. A process as claimed in claim 19 which comprises the steps of: (a) preparation of a miniemulsion (comprising monomers, a benefit agent, a perfume and a cosurfactant), and (b) polymerisation of the miniemulsion of step (a) to form miniemulsion core particles, and (c) addition of shell monomers and initiator such that polymerisation occurs to form a shell around the core particles of step (b), and attachment of a deposition aid around the particles.</p>

   <p>22. A process as claimed in claim 21 which comprises the steps of: -65 - (1) mixing monomers and a benefit agent with a cosurfactant to form a mixture (y), (ii) dissolving at least one surfactant in water to form a mixture (z), (iii) combining (y) and (z) and subjecting to high shear to form a miniemulsion, (iv) adding an initiator such that polymerisation proceeds to form a core, and (v) adding monomers, a deposition aid and initiators at such a rate so as to polymerise the monomers resulting in a shell around the core, with simultaneous attachment of a deposition aid onto the particles.</p>

   <p>23. A process as claimed in claim 19 which comprises the steps of: (a) preparation of a miniemulsion (comprising a polymer, a benefit agent, a perfume, a cosurfactant and a water insoluble volatile solvent), (b) removal of the volatile solvent, and (c) addition of shell monomers and initiator such that polymerisation occurs to form a shell around the core particles of step (b), wherein attachment of a deposition aid to the particles occurs in step (c).</p>

   <p>24. A process as claimed in claim 23 which comprises the steps of: -66 - (i) dissolving polymer, a benefit agent and a perfume with a cosurfactant in a water insoluble volatile solvent to form a mixture (m), (ii) dissolving at least one surfactant in water to form a mixture (n), (iii) combining (m) and (n) and subjecting to high shear to form a miniemulsion, (iv) removing the volatile solvent, and (v) adding shell monomers, a deposition aid and initiators at such a rate so as to polymerise the monomers resulting in a shell around the core, with simultaneous attachment of a deposition aid onto the polymer particles.</p>

   <p>25. A laundry treatment composition comprising the particle as claimed in any of claims 1 to 17.</p>

   <p>26. Use of a laundry treatment composition as claimed in claim 24 in the treatment of fabric.</p>

   <p>27. Use as claimed in claim 21 wherein the use provides a deposition benefit for the perfume onto the fabric.</p>

   <p>28. A method of treating fabric, comprising contacting the fabric with the polymer particle according to any one of claims 1 to 17.</p>

   <p>29. Use of a particle as claimed in any one of claims 1 to 17 in the treatment of a fabric to provide a perfume deposition benefit during a laundry process.</p>

   <p>-67 - 30. Use of a particle as claimed in any one of claims 1 to 17 in the manufacture of a laundry treatment composition to provide a perfume deposition benefit during a laundry process.</p>

   <p>31. Aqueous wash medium comprising from 0.05 to 1 gram per litre of a particle according to any one of claims 1 to 18.</p>