WO2009103615A1 - Improvements relating to benefit particles - Google Patents

Abstract

A fabric conditioning composition of pH less than 7 comprising: a) a quaternary ammonium fabric conditioning agent, preferably selected from ditallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, ditallow dimethyl ammonium chloride, dihydrogenatedtallow dimethyl ammonium chloride, ditallowoyloxyethyl methylhydroxyethylammonium methyl sulfate, dihydrogenated-tallowoyloxyethyl methyl hydroxyethylammonium chloride or combinations thereof; b) encapsulated particles comprise an inner shell of a formaldehyde polymer, preferably of the melamaine/urea formaldehyde type, and, an outer shell of a non-formaldehyde polymer, preferably of the vinyl acetate and/ or methyl acrylate type, and; c) a formaldehyde scavenger, preferably selected from the group comprising urea, ethylene urea, ethylacetamide, acetoacetamaide and mixtures thereof.

Description

IMPROVEMENTS RELATING TO BENEFIT PARTICLES

TECHNICAL FIELD

The present invention relates to particles comprising a benefit agent (typically, but not exclusively, a perfume) and their uses in both the formulation of laundry detergent compositions and delivery of, for example, perfume to fabric during laundering. Laundry treatment compositions containing particles according to the invention provide deposition efficiency benefits during washing without certain negatives associated with known compositions.

BACKGROUND OF THE INVENTION

Methods of perfume deposition from laundry compositions are diverse and perfume is often incorporated into a carrier or other delivery system. Carrier systems for perfumes are typically based on encapsulation or entrapment of the perfume within a matrix. The perfume may simply be emulsified, but deposition onto a substrate, such as fabric, is often inefficient and problems with poor retention or stability may be found. Preparation of materials by diffusion of the perfume into a carrier can require complex preparation, long times of diffusion, and may suffer from poor retention of the perfume in the matrix and subsequent poor substrate deposition.

Surfactants are characteristically very efficient at combining with oily materials such as perfumes and removing them. Therefore deposition onto a surface and longevity of adherence of the perfume in a surfactant containing environment, is inherently poor. This results in any deposited perfume being washed off during a main wash, or in the perfume being leached from its carrier in the wash liquor and becoming unavailable for deposition onto the fabric. Perfume encapsulates have been proposed as a means of overcoming these problems and include those described in: US 2003-215417; US 2003-216488; US 2003-158344;

US 2003-165692; US 2004-071742; US 2004-071746; US 2004-072719; US 2004-072720; EP 1393706; US 2003-203829; US 2003-195133; US 2004-087477; US 2004-0106536; US 6645479; US 6200949; US 4882220; US 4917920; US 4514461 and US 4234627.

Our co-pending application GB 0710369.0 is concerned with a process for the manufacture of core/shell perfume particles which comprise a non-ionic deposition aid. By changing the materials present during the polymerisation process it is possible to ensure that the non-ionic deposition aid is predominantly attached to the outer surface of the particles. Typically the shell comprise an inner layer of melamine/urea-formaldehyde formed by polymerisation of melamine/urea (or mixtures thereof) and formaldehyde monomers, and an outer layer formed from ethylenically-unsaturated monomers, particularly vinyl acetate and methyl acrylate. The application suggests the use of these capsules both in laundry main wash compositions and in rinse conditioners and illustrates its preferred embodiments with examples of laundry compositions.

The use of melamine/urea-formaldehyde as an encapsulating medium has raised issues over the formaldehyde levels on products. Several patent applications have mentioned this problem. EP 1797947 discloses how formaldehyde levels can be reduced by incorporation of a formaldehyde scavenger. This provides an encapsulate slurry with low levels of formaldehyde. EP 1797947 discusses the incorporation of formaldehyde scavengers in a range of formulations with a range of different types of encapsulated perfumes. A similar proposal is found in WO 2007/091223 which is particularly concerned with rinse conditioners. Despite these advances, we have identified that a potential problem still arises with rinse conditioners of acid pH when urea-formalydehyde or melamine- formaldehyde capsules are incorporated in the formulation. In these compositions acid hydrolysis of the aminoplast capsule material may take place and release formaldehyde. This counteracts efforts to prevent the carry-over of formaldehyde from the production process. The problem increases with prolonged storage at elevated temperatures.

EP 1767614 (Takasago) proposes the addition of an excess of urea or melamine as a way of reducing formaldehyde levels.

EP 1797946 (IFF) is concerned with "high stability microcapsules" for use in rinse- conditioners. These comprise both a melamine-formaldehyde resin and an acrylamine/acrylic acid polymer. The acrylamine/acrylic acid polymer is a water soluble polymer and is used in the reaction to cross link the melamine- formaldehyde resin to give greater stability.

BRIEF DESCRIPTION OF THE INVENTION

We have determined that liquid rinse conditioners which have and maintain surprisingly low levels of formaldehyde development on storage can be made provided that their perfume encapsulates are characterised by the presence of an outer layer of non-formaldehyde polymer on an encapsulate comprising an inner region which comprises a formaldehyde based polymer.

Accordingly a first aspect of the present invention comprises a fabric conditioning composition of pH less than 7 comprising:

a) a quaternary ammonium fabric conditioning agent, - A -

b) an encapsulated benefit agent wherein said encapsulates are made at least part from a formaldehyde-based polymer, and, at least in part from a non-formaldehyde based polymer, and

c) a formaldehyde scavenger.

The present invention will be further discussed with reference to the benefit agent being perfume, which is by far the most preferred benefit agent. However, further benefit agents can be present in addition to or as an alternative to perfume. Suitable benefit agents are preferably relatively high value materials having a post-wash benefit these include, but are not limited to, odourless essential oils, insect repellents, sunscreens, anti-oxidants, antimicrobial compounds, and skin benefit agents.

Encapsulated perfumes herein are any encapsulated perfumes having the form of discrete particles having sizes sufficiently small to be dispersed or suspended in the fabric conditioning compositions herein, so that they are pourable from the package along with the fabric conditioning compositions. "Encapsulated" means that there will be present coating layers enclosing the perfume.

The perfume contained in the encapsulate can be in liquid or solid form and can be homogeneously or non-homogeneously distributed. Suitable particle sizes range from nanometer scale to micron scale and even to millimeter scale. Typical particle sizes range from 1 micron to 1 mm, with particle sizes in the range of 5-50 microns being preferred, especially particles of 10-30 microns. In embodiments herein, encapsulated perfume leaves little or no visible residues on fabrics onto which it is deposited.

In preferred embodiments perfume encapsulates have a measurable increase in deposition onto fabrics during laundering with the detergent, by virtue of chemical and/or physical mechanisms ranging from having a particle size suitable for being entrapped in fabrics by filtration, through to electrostatic attraction to fabrics by virtue of having an opposite net surface charge. Particularly preferred particles are provided with a non-ionic or anionic deposition aid which is selectively substantive to fabrics.

DETAILED DESCRIPTION OF THE INVENTION

In order that the present invention may be further understood it is described in further detail below with reference to preferred features. At percentages used herein are wt% unless stated otherwise and all ratios are weight ratios unless stated otherwise.

The polymer particles of the invention can comprise a wide selection of monomer units provided that at least some of those present comprise formaldehyde or have the capacity to release formaldehyde on exposure to an acidic environment. By "monomer units" as used herein is meant the monomer 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.

The monomer units are preferably derived from monomers which are suitable for either step growth polymerisation or addition/free radical polymerisation.

In the most particularly preferred embodiment of the invention:

a) the monomers for step-growth polymerisation are those which can undergo acid hydrolysis to release formaldehyde and these polymers are localised in an inner shell surrounding and enclosing the perfume material, and, b) the monomers for addition/free radical polymerisation do not undergo acid hydrolysis to release formaldehyde and are present in an outer shell surrounding and enclosing the shell formed from the monomers for step- growth polymerisation

Advantageously, the compositions of the present invention not only have a low initial level of formaldehyde (i.e. low levels of formaldehyde left over from the encapsulation process) but also maintain a low level of formaldehyde. It is believed that this is due to the protective effect of the outer shell.

"Inner" and "outer" in regard to the shells are used in a relative sense and while it is preferred that they are equivalent to "innermost" and "outermost" they are not intended to be so limited.

Monomers for step growth polymerisation:

Suitable classes of such monomers are given in the group consisting of the melamine/formaldehyde class and the urea/formaldehyde class. Although melamine is specifically mentioned for use in the practice of this invention, and is generally preferred, the melamine may be partially or totally replaced with other suitable amine-containing compounds.

Other suitable compounds include urea, thiourea, dicyandiamide, melem (1 ,3,4,6,7,9,9b-Heptaazaphenalene), melam (N2-(4,6-diamino-1 ,3,5-triazin-2-yl)- 1 ,3,5-Thazine-2,4,6-Triamine), melon (where the heptazine is polymerized with the tri-s-triazine units linked through an amine link), ammeline (4,6-Diamino-2- hydroxy-1 ,3,5-triazine), ammelide (6-Amino-2,4-Dihydroxy-l,3,5-Thazine ), substituted melamines, guanamines, or mixtures thereof. Substituted melamines include the alkyl melamines and aryl melamines which can be mono, di-, or tri-substituted. In the alkyl-substituted melamines, each alkyl group can contain from 1 to 6 carbons, preferably from 1 to 4 carbons.

Representative examples of some alkyl-substituted melamines are monomethylmelamine, dimethyl melamine, trimethyl melamine, monoethyl melamine, and 1-methyl-3-propyl-5-butyl melamine. In the aryl-substituted melamines, each aryl group can contain 1 -2 phenyl moieties and, preferably, 1 phenyl moiety. Typical examples of an aryl-substituted melamine are monophenyl melamine or diphenyl melamine. Based on considerations of cost and availability, Standard melamine is generally preferred.

Preferred are particles having an inner shell of the melamine- and/or urea- formaldehyde class. Perfume particles which consist only of melamine/urea formaldehyde shells are widely manufactured by well understood processes which give a relatively high perfume loading.

The urethane polymers are also made by step-growth polymerisation but do not release formaldehyde on hydrolysis. Consequently the urethane polymers are suitable for the outer shell of the particle.

Monomers for addition/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 α,β-monoethylenically unsaturated mono- and dicarboxylic acids with alcohols, nitriles of α,β-monoethylenically unsaturated carboxylic acids, conjugated dienes, α,β-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.

The polymer particle may optionally comprise monomers which are cross-linkers. Such crosslinkers may have at least two non-conjugated ethylenically unsaturated double bonds. 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 10 % by weight, based on the total amount of monomers to be polymerised.

The monomers preferably comprise and more preferably consist of monomers selected from: styrene; α-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. The preferred monomers are vinyl acetate and methyl acrylate.

Optionally, the monomers are used as co-polymers with one or more of 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 methacrylate, vinyl pyridine, vinyl carbazole, vinyl imidazole, vinyl aniline, and their cationic forms after treatment with alkyl halides;

Optional cross linkers include 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.

The most preferred monomers for the outer shell are vinyl acetate and/or methyl acrylate. These are preferably used in combination with the most preferred monomers for the inner shell, particularly the melamine/urea formaldehyde polymers.

It is preferable that the ratio of the monomers used in the inner and outer shell formation are the ratio of 20:1 to 1 :1 (as innenouter). Preferably, the ratio is 5:1 - 2:1 , more preferably 4:1-2:1.

Formaldehyde scavenger:

As noted above, the compositions of the present invention comprise a formaldehyde scavenger. The formaldehyde scavengers disclosed in EP 1797947 can be used in embodiments of the invention.

The formaldehyde scavengers of the present invention are preferably selected from beta-dicarbonyl compounds, mono- or di-amide materials, amines and other materials which can react with formaldehyde and remove it. Suitable beta-dicarbonyl compounds of the present have an acidic hydrogen giving rise to a nucleophilic attack on formaldehyde.

Preferred beta-dicarbonyl compounds are acetoacetamide (BKB (available in the marketplace from Eastman)), ethyl acetoacetate (EAA (available in the marketplace from Eastman)), N,N-Dimethyleneacetamide (DMAA (available in the marketplace from Eastman)), acetoacetone, dimethyl-1 ,3-acetonedicarboxylate, 1 ,3-acetonedicarboxylic acid, malonic acid, resorcinol, 1 ,3-cyclohexadione, barbituric acid, 5,5-dimethyl-1 ,3-cyclohexanedione (dimedone), 2,2-dimethyl-1 ,3- dioxane-4,6-dione (Meldrum's acid), salicylic acid, methyl acetoacetate (MAA (available in the marketplace from Eastman)), ethyl-2-methyl acetoacetate, 3- methyl-acetoacetone, dimethyl malonate, diethyl malonate, 1 ,3-dimethyl barbituric acid, resorcinol, phloroglucinol, orcinol, 2,4-dihydroxy benzoic acid, 3,5- dihydroxy benzoic acid, and malonamide. Other suitable beta-dicarbonyl scavenger are listed in U.S. 5,194,674 and 5,446,195 as well as in Tomasino et al, Textile Chemist and Colorist, vol. 16, No. 12 (1984),

Mono or Di-amides may also be used as effective formaldehyde scavengers.

Examples of the preferred effective mono- and di-amide scavengers are urea, ethylene urea, propylene urea, caprolactam, glycouril, hydantoin, 2-oxazolidinone, 2-pyrrolidinone, uracil, barbituric acid, thymine, uric acid, allantoin, polyamides, 4,5-dihydroxyethylene urea, monomethylol-4-hydroxy-4-methoxy-5,5-dimethyl- propylurea, nylon 2-hydroxyethyl ethylene urea (SR-511 ; SR-512 (Sartomer)), 2- hydroxyethyl urea (Hydrovance (National Starch)), L-citrulline, biotin, N-methyl urea, N-ethyl urea, N-butyl urea, N-phenyl urea, 4,5-dimethoxy ethylene urea and succinimide.

Another class of compounds that are effective formaldehyde scavengers are amines which form imines by reaction with formaldehyde. Preferred amines include, polyvinyl amine) (Lupamin™ (BASF)), arginine, lysine, asparagines, proline, tryptophan, 2-amino-2-methyl-1 -propanol (AMP); proteins such as casein, gelatin, collagen, whey protein, soy protein, and albumin; melamine, benzoguanamine, 4-aminobenzoic acid (PABA), 3-aminobenzoic acid, 2-aminobenzoic acid (anthranilic acid), 2-aminophenol, 3-aminophenol, 4- aminophenol, creatine, 4-aminosalicylic acid, 5-aminosalicylic acid, methyl anthranilate, methoxylamine HCI, anthranilamide, 4-aminobenzamide, p-toluidine, p-anisidine, sulfanilic acid, sulfanilamide, methyl-4-aminobenzoate, ethyl-4- aminobenzoate (benzocain), beta-diethylaminoethyl-4-aminobenzoate (procain), 4-aminobenzamide, 3,5-diaminobenzoic acid and 2,4-diaminophenol.

Other amines as disclosed in copending U.S. Letters for Patent Application Number 11/123,898 and U.S. 6,261 ,483, and in Tomasino et al, Textile Chemist and Colorist, vol. 16, No. 12 (1984).

Other formaldehyde scavengers are known, for example, hydrazines such as 2,4- dinitrophenzylhydrazine react with formaldehyde to give hydrazones. The reaction is pH-dependent and reversible. Other preferred amines can be selected from a non-limiting list of 1 ,2-phenylenediamine, 1 ,3-phenylenediamine, and 1 ,4- phenylenediamine.

In addition, aromatic amines, triamines, and aliphatic polyamine may also be used. Examples of these amines may include, but are not limited to, aniline, hexamethylene-diamine, bis-hexamethylenetriamine, thethyl-aminethamine, poly(propyleneoxide)triamine, and poly(propyleneglycol)-diamines.

The formaldehyde scavengers of WO 2007/091223 may also be used in embodiments of the invention. These are sodium bisulfite, urea, cysteine, cysteamine, lysine, glycine, serine, carnosine, histidine, glutathione, 3,4- diaminobenzoic acid, allantoin, glycouril, anthranilic acid, methyl anthranilate, methyl 4- aminobenzoate, ethyl acetoacetate, acetoacetamide, malonamide, ascorbic acid, 1 ,3- dihydroxyacetone dinner, biuret, oxamide, benzoguanamine, pyroglutamic acid, pyrogallol, methyl gallate, ethyl gallate, propyl gallate, triethanol amine, succinamide, thiabendazole, benzotriazol, triazole, indoline, sulfanilic acid, oxamide, sorbitol, glucose, cellulose, polyvinyl alcohol), polyvinyl amine), hexane diol, ethylenediamine-N,N'-bisacetoacetamide, N-(2- ethylhexyl)acetoacetamide, N-(3-phenylpropyl)acetoacetamide, lilial, helional, melonal, triplal, 5,5-dimethyl-l,3- cyclohexanedione, 2,4-dimethyl-3-cyclohexenecarboxaldehyde, 2,2-dimethyl- 1, 3- dioxan-4,6-dione, 2-pentanone, dibutyl amine, thethylenetetramine, benzylamine, hydroxycitronellol, cyclohexanone, 2-butanone, pentane dione, dehydroacetic acid, chitosan, and/or mixtures thereof.

Particularly preferred scavengers comprise at least one of urea, ethylene urea, ethylacetamide, acetoacetamide and mixtures thereof. The most preferred scavengers are selected from the group consisting of urea, ethylene urea, ethylacetamide, acetoacetamide and mixtures thereof.

The level of formaldehyde scavenger is preferably less than 0.1 %wt, preferably less than 0.065%wt of the final product. Minimum levels of formaldehyde scavenger will be no less than 200ppm. Typical levels in a product will be 0.02- 0.10%wt.

Optional deposition aid:

A deposition aid can be incorporated in the outermost shell. The deposition aid can be nonionic, cationic or anionic.

In one preferred embodiment, the deposition aid is a polysaccharide. In these embodiments the polysaccharide preferably has a β-1 ,4-linked backbone and is substantive to cellulose. Preferably the polysaccharide is a cellulose, a cellulose derivative, or another β-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.

Polysaccharides can act as thickeners when added to an emulsion system, such as that employed herein. One problem with increased viscosity is it can determine how much polysaccharide one can coat a capsule with, and on a large scale flexibility of processing can be compromised. We have determined that selection of the polysaccharide type can modify the viscosity.

Preferably, the polysaccharide backbone has only β-1 ,4 linkages. Optionally, the polysaccharide has linkages in addition to the β-1 ,4 linkages, such as β-1 ,3 linkages. Thus, optionally some other linkages are present.

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

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.

Preferably, the polysaccharide is present at levels of between 0.1 % to 10% w/w by weight of the total amount of the particle. An alternative non-ionic or anionic deposition aid is one which is substantive to polyester.

Preferably the polyester-substantive deposition aid is a polymer derivable from dicarboxylic acids and polyols, particularly a phthalate containing polymer, more preferably a polymer comprising units derived from (poly)ethylene glycol and terephthalate. Most preferably the polymer is a selected from the group comprising PET/POET, PEG/POET, PET/PEG and phthalate/glycerol/ethylene glycol polymers. Materials of this type are widely available to the laundry formulator as they are commonly used as soil-release polymers.

Any polymeric soil release agent known to those skilled in the art can be employed in compositions according to the invention. Polymeric soil release agents are characterized by having both hydrophilic segments, to hydrophilize the surface of hydrophobic fibers, such as polyester and nylon, and hydrophobic segments, to deposit upon hydrophobic fibers and remain adhered thereto through completion of washing and rinsing cycles and, thus, serve as an anchor for the hydrophilic segments. This is commonly done to enable stains occurring subsequent to treatment with the soil release agent to be more easily removed in later washing procedures.

The polymeric deposition aids useful herein especially include those soil release agents having one or more nonionic hydrophilic components comprising oxyethylene, polyoxyethylene, oxypropylene or polyoxypropylene segments, and, one or more hydrophobic components comprising terephthalate segments. Typically, oxyalkylene segments of these deposition aids will have a degree of polymerization of from 1 to about 400, although higher levels can be used, preferably from 100 to about 350, more preferably from 200 to about 300. One type of preferred deposition aid is a copolymer having random blocks of ethylene terephthalate and polyethylene oxide terephthalate. The preferred molecular weight of this class of polymeric deposition aid agent is in the range of from about 5kD to about 55kD.

Another preferred polymeric deposition aid is polyester with repeat units of ethylene terephthalate units contains 10-15% by weight of ethylene terephthalate units together with 90-80% by weight of polyoxyethylene terephthalate units, derived from a polyethylene glycol of average molecular weight 0.2kD-40kD. Examples of this class of polymer include the commercially available material ZELCON 5126 (from DuPont) and MILEASE T (from ICI). Examples of related polymers can be found in US 4702857.

Another preferred polymeric deposition aid is a sulfonated product of a substantially linear ester oligomer comprised of an oligomeric ester backbone of terephthaloyl and oxyalkyleneoxy repeat units and terminal moieties covalently attached to the backbone. These soil release agents are described fully in US 4968451. Other suitable polymeric soil release agents include the terephthalate polyesters of US 4711730, , the anionic end-capped oligomeric esters of US 4721580, and the block polyester oligomeric compounds of US 4702857,..

Preferred polymeric deposition aids also include the soil release agents of U.S. 4877896 which discloses anionic, especially sulfoarolyl, end-capped terephthalate esters.

Still another preferred deposition aid is an oligomer with repeat units of terephthaloyl units, sulfoisoterephthaloyl units, oxyethyleneoxy and oxy-1 ,2- propylene units. The repeat units form the backbone of the oligomer and are preferably terminated with modified isethionate end-caps. A particularly preferred deposition aid of this type comprises about one sulfoisophthaloyl unit, 5 terephthaloyl units, oxyethyleneoxy and oxy-1 ,2-propyleneoxy units in a ratio of from about 1.7 to about 1.8, and two end-cap units of sodium 2-(2- hydroxyethoxy)-ethanesulfonate. Said soil release agent also comprises from about 0.5% to about 20%, by weight of the oligomer, of a crystalline-reducing stabilizer, preferably selected from the group consisting of xylene sulfonate, cumene sulfonate, toluene sulfonate, and mixtures thereof.

The microencapsulates used in the practice of the present invention may be coated with a cationic polymer. Suitable cationic polymers include those as disclosed in Application for U.S. Letters patent Ser. No. 10/718,240 filed on Nov. 20, 2003 and, in addition, Applications for U.S. patent Ser. Nos. 10/268,566 and 10/268,526 filed on Oct. 10, 2002. Examples of such cationic polymers used as coatings are cationically modified starch and cationically modified guar, polymers comprising poly diallyl dimethyl ammonium halides (PoIyDADMAC), and copolymers of DADMAC with vinyl pyrrolidone, acrylamides, imidazoles, imidazolinium halides, and the like. For instance, Polyquaternium-6, 7, 22 and 39, all available from Ondeo Nalco.

Preferred cationic starches, which can also be used, have a molecular weight of from about 100,000 to about 500,000,000, preferably from about 200,000 to about 10,000,000 and most preferably from about 250,000 to about 5,000,000. Particularly preferred cationic starch products are HI-CAT CWS42 and HI-CAT 02 and are commercially available from ROQUETTE AMERICA, Inc.

The preferred cationic guar has a molecular weight of from about 50,000 to about 5,000,000. The preferred cationic guar products are Jaguar C-162 and Jaguar C-17 and are commercially available from Rhodia Inc. The deposition aid may be straight or branched. Preferably, the polymer is present at levels of between 0.1 % to 10% w/w by weight of the total amount of the particle.

The deposition aid is preferably attached to the particle 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 deposition aid becomes buried within the interior of the particle. Hence at the end of the polymerisation, part of the deposition aid is entrapped and bound in the polymer matrix of the particle, whilst the remainder is free to extend into the aqueous phase.

By strong adsorption as used herein is meant strong adsorption of the deposition aid to the surface of the particle; such adsorption can, for example, occur due to hydrogen bonding, Van Der Waals or electrostatic attraction between the deposition aid and the particle.

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 deposition aid is required to achieve the same level of activity as systems which utilise polysaccharide copolymers.

Other types of particle surface morphology may be produced when a deposition aid is attached to the particle of the invention. For example, where a polysaccharide attaches to the particle surface in multiple places, loops may result, or the deposition aid may be in the form of a swollen polymer layer at the particle surface.

In one particularly preferred aspect of the invention the deposition aid is grafted with a polymer prior to addition to the reaction mixture containing the particles.

The most preferred particles according to the present invention are those in which the monomers for the outer shell are vinyl acetate and/or methyl acrylate, the monomers for the inner shell are of the melamine/urea formaldehyde type, the deposition aid is a polysaccharide (preferably a beta 1-4 and more preferably locust bean gum) and at least one of the formaldehyde scavengers is selected from the group consisting of urea, ethylene urea, ethylacetamide, acetoacetamide and mixtures thereof.

Perfumes:

The benefit agent is most preferably a perfume which is typically present in an amount of from 10-85% by total weight of the particle, preferably from 20 to 75 % by total weight of the particle.

The perfume suitably has a molecular weight of from 50 to 500.

Useful components of the perfume include materials of both natural and synthetic origin. They include single compounds and mixtures. Specific examples of such components may be found in the current literature, e.g., in Fenaroli's Handbook of Flavor Ingredients, 1975, CRC Press; Synthetic Food Adjuncts, 1947 by M. B. Jacobs, edited by Van Nostrand; or Perfume and Flavor Chemicals by S. Arctander 1969, Montclair, N.J. (USA). These substances are well known to the person skilled in the art of perfuming, flavoring, and/or aromatizing consumer products, i.e., of imparting an odor and/or a flavor or taste to a consumer product traditionally perfumed or flavored, or of modifying the odor and/or taste of said consumer product.

By perfume in this context is not only meant a fully formulated product fragrance, but also selected components of that fragrance, particularly those which are prone to loss, such as the so-called 'top notes'.

Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Examples of well known top-notes include citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol. Top notes typically comprise 15-25%wt of a perfume composition and in those embodiments of the invention which contain an increased level of top-notes it is envisaged at that least 20%wt would be present within the encapsulate.

Typical perfume components which it is advantageous to encapsulate, include those with a relatively low boiling point, preferably those with a boiling point of less than 300, preferably 100-250 Celsius.

It is also advantageous to encapsulate perfume components which have a low LogP (ie. those which will be partitioned into water), preferably with a LogP of less than 3.0. These materials, of relatively low boiling point and relatively low LogP have been called the "delayed blooming" perfume ingredients and include the following materials: AIIyI Caproate, Amyl Acetate, Amyl Propionate, Anisic Aldehyde, Anisole, Benzaldehyde, Benzyl Acetate, Benzyl Acetone, Benzyl Alcohol, Benzyl Formate, Benzyl lso Valerate, Benzyl Propionate, Beta Gamma Hexenol, Camphor Gum, Laevo-Carvone, d-Carvone, Cinnamic Alcohol, Cinamyl Formate, Cis-Jasmone, cis-3-Hexenyl Acetate, Cuminic Alcohol, Cyclal C, Dimethyl Benzyl Carbinol, Dimethyl Benzyl Carbinol Acetate, Ethyl Acetate, Ethyl Aceto Acetate, Ethyl Amyl Ketone, Ethyl Benzoate, Ethyl Butyrate, Ethyl Hexyl Ketone, Ethyl Phenyl Acetate, Eucalyptol, Eugenol, Fenchyl Acetate, Flor Acetate (tricyclo Decenyl Acetate), Frutene (thcyclco Decenyl Propionate), Geraniol, Hexenol, Hexenyl Acetate, Hexyl Acetate, Hexyl Formate, Hydratropic Alcohol, Hydroxycitronellal, Indone, lsoamyl Alcohol, lso Menthone, lsopulegyl Acetate, Isoquinolone, Ligustral, Linalool, Linalool Oxide, Linalyl Formate, Menthone, Menthyl Acetphenone, Methyl Amyl Ketone, Methyl Anthranilate, Methyl Benzoate, Methyl Benyl Acetate, Methyl Eugenol, Methyl Heptenone, Methyl Heptine Carbonate, Methyl Heptyl Ketone, Methyl Hexyl Ketone, Methyl Phenyl Carbinyl Acetate, Methyl Salicylate, Methyl-N-Methyl Anthranilate, Nerol, Octalactone, Octyl Alcohol, p- Cresol, p-Cresol Methyl Ether, p-Methoxy Acetophenone, p-Methyl Acetophenone, Phenoxy Ethanol, Phenyl Acetaldehyde, Phenyl Ethyl Acetate, Phenyl Ethyl Alcohol, Phenyl Ethyl Dimethyl Carbinol, Prenyl Acetate, Propyl Bornate, Pulegone, Rose Oxide, Safrole, 4-Terpinenol, Alpha-Terpinenol, and /or Viridine

It is commonplace for a plurality of perfume components to be present in a formulation. In the encapsulates of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components from the list given of delayed blooming perfumes given above present in the encapsulated perfume.

Another group of perfumes with which the present invention can be applied are the so-called 'aromatherapy' materials. These include many components also used in perfumery, including components of essential oils such as Clary Sage, Eucalyptus, Geranium, Lavender, Mace Extract, Neroli, Nutmeg, Spearmint, Sweet Violet Leaf and Valerian. By means of the present invention these materials can be transferred to textile articles that will be worn or otherwise come into contact with the human body (such as handkerchiefs and bed-linen).

Encapsulation process details

As noted above the process for the preparation of the particles is preferably a two step process in which the first step forms a capsule and the second step applies a coating to it. The first step can either be step-growth or addition polymerisation and the second step is preferably addition polymerisation.

It is particularly preferably that the first step uses monomers selected from melamine/urea-formaldehyde and the second step uses monomers selected from vinyl acetate and/or methyl acrylate. It is particular preferred that the non-ionic deposition aid is not added until the second step.

For step-growth polymerisation some heating is generally necessary to cause polymerisation to proceed. Initiators and chain transfer agents may also be present in the polymerisation mixture where use is made of any addition polymerisation. Those skilled in the art will recognise that a chemical initiator will generally be required for addition polymerisation but that there are instances in which alternative forms of initiation will be possible, e.g. ultrasonic initiation or initiation by irradiation.

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). Suitably, in context of the invention, homolysis may be achieved by the application of heat (typically in the range of from 50 to 100⁰C). Some examples of suitable initiators in this class are those possessing peroxide (-O-O-) or azo (-N=N-) groups, such as benzoyl peroxide, t-butyl peroxide, hydrogen peroxide, azobisisobutyronitrile and ammonium persulphate. 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. Redox reactions can also be used to generate free radicals. 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.

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 ammonium 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.

Chain transfer agents can optionally be used. 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. 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.

The preferred product of such a process is a slurry or dispersion comprising some 30-60% of solids.

Cation ic Fabric Softeners

Suitable cationic fabric softening compounds (FSCs) 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. Substantially water-insoluble FSCs are defined as FSCs having a solubility of less than 1 x 10^~3 wt% in demineralised water at 20°C. Preferably the FSCs have a solubility of less than 1 x 10^~4 wt%, more preferably from less than 1 x 10^"8 to 1 x 10^"6 wt%.

Preferably the FSCs 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 groups of the FSCs are predominantly linear.

Examples suitable include dialkydimethylammonium salts and dialkylene dimethylammonium salts such as ditallow dimethylammonium chloride and ditallow dimethylammonium methylsulfate. Examples of commercially available dialkyl(ene) dimethylammonium salts usable in the present invention are di- hydrogenated tallow dimethyl ammonium chloride and ditallow dimethyl ammonium chloride available from Degussa under the trade names Adogen® 442 and Adogen® 470 respectively.

Other examples of FSCs 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".

The preferred quaternary ammonium fabric conditioner for use in the compositions of the present invention are so-called "ester quats".

Particularly preferred materials are the ester-linked triethanolammonium (TEA) quaternary ammonium compounds comprising a mixture of mono-, di- and tri- ester linked components.

Typically, TEA-based fabric softening compounds comprise a mixture of mono, di- and tri-ester forms of the compound where the di-ester linked component compises 70-45%wt and at least 5%wt of the monoester linked component is present.

A first group of quaternary ammonium compounds (QACs) suitable for use in the present invention is represented by formula (I): [(CH₂)n(TR)]_m-(R¹).N⁺-[(CH2)n(OH)]_3-m X^" (I)

wherein each R is independently selected from a C_5-35 alkyl or alkenyl group; R¹ represents a Ci_-4 alkyl, C_2-4 alkenyl or a Ci_-4 hydroxyalkyl group; T is generally O-CO. (i.e. an ester group bound to R via its carbon atom), but may alternatively be CO. O (i.e. an ester group bound to R via its oxygen atom); n is a number selected from 1 to 4; m is a number selected from 1 , 2, or 3; and X^" is an anionic counter-ion, such as a halide or alkyl sulphate, e.g. chloride or methylsulphate. Di-esters variants of formula I (i.e. m = 2) are preferred and typically have mono- and tri-ester analogues associated with them. Such materials are particularly suitable for use in the present invention.

Especially preferred agents are preparations which are rich in the di-esters of triethanolammonium methylsulphate, otherwise referred to as "TEA ester quats".

Commercial examples include Prapagen™ TQL, ex Clariant, and Tetranyl™ AHT- 1 , ex Kao, (both di-[hardened tallow ester] of triethanolammonium methylsulphate), AT-1 (di-[tallow ester] of triethanolammonium methylsulphate), and L5/90 (di-[palm ester] of triethanolammonium methylsulphate), both ex Kao, and Rewoquat™ WE15 (a di-ester of triethanolammonium methylsulphate having fatty acyl residues deriving from C10-C20 and Ci₆-Ci₈ unsaturated fatty acids), ex Degussa.

A second group of QACs suitable for use in the invention is represented by formula (II):

(R¹)₃N⁺-(CH₂)_n-CH.( CH₂TR²)-TR² X^" (II) wherein each R¹ group is independently selected from Ci_-4 alkyl, hydroxyalkyl or C_2-4 alkenyl groups; and wherein each R² group is independently selected from Cs-28 alkyl or alkenyl groups; and wherein n, T, and X^" are as defined above.

Preferred materials of this second group include 1 ,2 ιb/s[tallowoyloxy]-3- trimethylammonium propane chloride, 1 ,2 ιb/s[hardened tallowoyloxy]-3- trimethylammonium propane chloride, 1 ,2-ιb/s[oleoyloxy]-3-trimethylammonium propane chloride, and 1 ,2 ιb/s[stearoyloxy]-3-trimethylammonium propane chloride. Such materials are described in US 4,137,180 (Lever Brothers). Preferably, these materials also comprise an amount of the corresponding mono-ester.

A third group of QACs suitable for use in the invention is represented by formula (III):

(R¹)2-N⁺-[(CH₂)n-T-R²]₂ X- (III)

wherein each R¹ group is independently selected from Ci_-4 alkyl, or C_2-4 alkenyl groups; and wherein each R² group is independently selected from Cs_-2S alkyl or alkenyl groups; and n, T, and X^" are as defined above. Preferred materials of this third group include bis(2-tallowoyloxyethyl)dimethyl ammonium chloride and hardened versions thereof.

The iodine value of the quaternary ammonium fabric conditioning material is preferably from 0 to 80, more preferably from 0 to 60, and most preferably from 0 to 45. Essentially saturated material, i.e. having an iodine value of from 0 to 1 , is used in especially high performing compositions. At low iodine values, the softening performance is excellent and the composition has improved resistance to oxidation and associated odour problems upon storage. Low iodine values are also preferred in the presence of the photo-bleaches of the present invention. While some reaction between the fatty chains of the fabric conditioners and the photo-bleach can be accommodated, and may even lead to the development of fragrance components, it is preferred that this only occurs at a low level, and that largely (less than 10% total 18:1 and 18:2) or effectively fully saturated conditioners are employed.

Iodine value is defined as the number of grams of iodine absorbed per 100 g of test material. NMR spectroscopy is a suitable technique for determining the iodine value of the softening agents of the present invention, using the method described in Anal. Chem., 34, 1136 (1962) by Johnson and Shoolery and in EP 593,542 (Unilever, 1993).

Particularly preferred FSCs include ditallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, ditallow dimethyl ammonium chloride, dihydrogenatedtallow dimethyl ammonium chloride, ditallowoyloxyethyl methylhydroxyethylammonium methyl sulfate, dihydrogenated- tallowoyloxyethyl methyl hydroxyethylammonium chloride, or combinations thereof.

Typical minimum levels of incorporation of the FSC in the compositions of the present invention are at least about 1 %, alternatively at least about 2%, alternatively at least about at least about 3%, alternatively at least about at least about 5%, alternatively at least about 10%, and alternatively at least about 12%, by weight of the fabric care composition. The fabric care composition may typically comprise maximum levels of FSA of about less than about 90%, alternatively less than about 40%, alternatively less than about 30%, alternatively less than about 20%, by weight of the composition. Co-softeners may be used. When employed, they are typically present at from 0.1 to 20% and particularly at from 0.5 to 10%, based on the total weight of the composition. Preferred co-softeners include fatty esters, and fatty N-oxides. Fatty esters that may be employed include fatty monoesters, such as glycerol monostearate, fatty sugar esters, such as those disclosed WO 01/46361 (Unilever).

The compositions of the present invention will preferably comprise a fatty co-softener.

Especially suitable fatty co-softeners include fatty alcohols and fatty acids. Of these, fatty alcohols are most preferred.

Preferred fatty acids include hardened tallow fatty acid (available under the tradename Pristerene™, ex Uniqema). Preferred fatty alcohols include hardened tallow alcohol (available under the tradenames Stenol™ and Hydrenol™, ex Cognis and Laurex™ CS, ex Albright and Wilson).

The fatty co-softener is preferably present in an amount greater than 0.3 to 5% by weight based on the total weight of the composition. More preferably, the fatty component is present in an amount of from 0.4 to 4%. The weight ratio of the mono-ester component of the quaternary ammonium fabric softening material to the fatty complexing agent is preferably from 5:1 to 1 :5, more preferably 4:1 to 1 :4, most preferably 3:1 to 1 :3, e.g. 2:1 to 1 :2.

It is preferred that the compositions further comprise a nonionic surfactant.

Typically these can be included for the purpose of stabilising the compositions.

Suitable nonionic surfactants include addition products of ethylene oxide and/or propylene oxide with fatty alcohols, fatty acids and fatty amines. Any of the alkoxylated materials of the particular type described hereinafter can be used as the nonionic surfactant.

Suitable surfactants are substantially water soluble surfactants of the general formula:

R-Y-(C₂H₄O)_Z-CH₂-CH₂-OH

where R is selected from the group consisting of primary, secondary and branched chain alkyl and/or acyl hydrocarbyl groups; primary, secondary and branched chain alkenyl hydrocarbyl groups; and primary, secondary and branched chain alkenyl-substituted phenolic hydrocarbyl groups; the hydrocarbyl groups having a chain length of from 8 to about 25, preferably 10 to 20, e.g. 14 to 18 carbon atoms.

In the general formula for the ethoxylated nonionic surfactant, Y is typically:

-O- , -C(O)O-- , -C(O)N(R)- or -C(O)N(R)R-

in which R has the meaning given above or can be hydrogen; and Z is at least about 8, preferably at least about 10 or 11.

Preferably the nonionic surfactant has an HLB of from about 7 to about 20, more preferably from 10 to 18, e.g. 12 to 16. Genapol™ C200 (Clariant) based on coco chain and 20 EO groups is an example of a suitable nonoionic surfactant.

The nonionic surfactant is present in an amount from 0.01 to 10%, more preferably 0.1 to 5 by weight, based on the total weight of the composition. The most preferred compositions according to the present invention are those in which the monomers for the outer shell of the particles are vinyl acetate and/or methyl acrylate, the monomers for the inner shell of the particles are of the melamine/urea formaldehyde type, the deposition aid used in the particles is a polysaccharide (preferably locust bean gum), the formaldehyde scavenger is selected from the group consisting of urea, ethylene urea, ethylacetamide, acetoacetamide and mixtures thereof and the cationic fabric softener is selected from the group consisting of ditallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated-tallowoyloxyethyl dimethyl ammonium chloride, ditallow dimethyl ammonium chloride, dihydrogenatedtallow dimethyl ammonium chloride, ditallowoyloxyethyl methylhydroxyethylammonium methyl sulfate, dihydrogenated- tallowoyloxyethyl methyl hydroxyethylammonium chloride, or combinations thereof

Further Optional Ingredients

The compositions of the invention may contain one or more other ingredients. Such ingredients include preservatives (e.g. antimicrobials including biocides and biostats), pH buffering agents, perfume carriers, hydrotropes, anti-redeposition agents, soil-release agents, polyelectrolytes, anti-shhnking agents, anti-wrinkle agents, anti-oxidants, sunscreens, anti-corrosion agents, drape imparting agents, anti-static agents and ironing aids. The products of the invention preferably contain pearlisers and/or opacifiers.

The preferred pH of the product is 2-4.

It is believed that those polymers which deposit on cloth as a part of their activity may also assist in the deposition of the perfume components present. These include cationic polymeric deposition aids. Suitable cationic polymeric deposition aids include cationic guar polymers such as Jaguar™ (ex Rhone Poulenc), cationic cellulose derivatives such as Celquats™ (ex National Starch), Flocaid™ (ex National Starch), cationic potato starch such as SoftGel™ (ex Aralose), cationic polyacrylamides such as PCG (ex Allied Colloids).

Product Form

A composition of the invention may be in dry solid or liquid form. The composition may be a concentrate to be diluted, rehydrated and/or dissolved in a solvent, including water, before use. The composition may also be a ready-to-use (in-use) composition. Preferably the compositon is provided as a ready to use liquid comprising an aqueous phase. The aqueous phase may comprise water-soluble species, such as mineral salts or short chain (C1 -4) alcohols.

The mineral salts may aid the attainment of the required phase volume for the composition, as may water soluble organic salts and cationic deflocculating polymers, as described in EP 41 ,698 A2 (Unilever). Such salts may be present at from 0.001 to 1 % and preferably at from 0.005 to 0.1 % by weight of the total composition. Examples of suitable mineral salts for this purpose include calcium chloride and magnesium chloride. The compositions of the invention may also contain pH modifiers such as hydrochloric acid. The short chain alcohols include primary alcohols, such as ethanol, propanol, and butanol, and secondary alcohols such as isopropanol. The short chain alcohol may be added with the cationic softening agent during the preparation of the composition.

The composition is preferably used in the rinse cycle of a home textile laundering operation, where, it may be added directly in an undiluted state to a washing machine, e.g. through a dispenser drawer or, for a top-loading washing machine, directly into the drum. Alternatively, it can be diluted prior to use. The compositions may also be used in a domestic hand-washing laundry operation. It is also possible, though less desirable, for the compositions of the present invention to be used in industrial laundry operations, e.g. as a finishing agent for softening new clothes prior to sale to consumers.

Method of Manufacture

In a typical method of manufacture, the cationic softening agent, and any optional components such as co-softener are heated together until a co-melt is formed. Water and other components are heated and the co-melt is added to the water with stirring. The phase volume of the disperse phase may be reduced by the addition of an electrolyte and/or by milling, preferably whilst the mixture is still hot.

The addition of perfume may be as a co-melt with the actives, as a separate addition stage similar to the addition of perfume, that is, at the end of the process stage when the batch is cooled or post dosed at the end of the process as a preformed emulsion with the perfume of the formulation.

The preferred method of perfume encapsulate addition is to add this at the end of the process. This prevents the possible degradation of the capsules and protects them from high temperature processing and shear.

In order that the present invention may be further understood and carried forth into practice it will be further described with reference to the following examples:

EXAMPLES:

The following experiments were done with fresh and aged capsules, wherein the aged capsules had been stored in a composition for 5 weeks at 37 Celsius. High performance liquid chromatography (HPLC) and fluorescence detection were employed to measure the levels of formaldehyde. Aqueous extractions of free formaldehyde from concentrated encapsulate slurries were performed prior to a filtration step, to remove particulate matter (including encapsulates). 100 mg diluted with water to a volume of 10 mis. Rotamixed and filtered via 1.2 μm/0.45 μm glass/PVDF membranes.

Reverse-phase HPLC separation on the resultant solutions was performed followed by a direct post-column dehvitisation of formaldehyde by in-flow addition of pentane-dione/ammonium reagent from a secondary pump in advance of mixing in a 500 μl reaction coil at 8O⁰C followed by fluorescence detection. An Agilent™ 1100 Series HPLC System.was used with a Hypersil™ ODS, 5 μm, 4.6 x 250 mm column. The elutent was ion-pure water.

The post column reagent was ammonium acetate (66.5 g), 2,4-pentane dione (5 mis), acetic acid (7.5 mis), diluted to a total volume of 1 litre with water. Flow rates were 0.7mls/min (separation eluent) & 0.4 mls/min (post column reagent). Injection volumes were 1 - 50 μl, dependant on sample concentration. Direct post-column mixing of analyte (separation eluent) and reagent was performed at 8O⁰C through a 500 μl reaction coil (Dionex™ PCH-2). Detection was by fluorescence, Ex = 400 nm, Em = 510 nm.

Measurements were standardised with formaldehyde solution (37%, stabilised with -10% methanol) diluted with water to give a typical concentration range of 0.4 - 20 ppm dependant on formaldehyde level of the samples. Linear external standard calibration was performed for calculation of sample formaldehyde concentration.

To modify melamine formaldehyde (MF) capsules with polyvinyl acetate (PVAc) and or poly methacylate (PMA), the following method was used: Locust bean gum (5 g) was dissolved in hot (70-80 C) de-ionised water (50Og) by mixing with a high speed homogeniser (Silverson™) at 10,000rpm for 10 minutes until completely solubilised. The solution was then allowed to cool to room temperature under static conditions.

A reaction vessel fitted with an overhead stirrer, condenser, thermocouple (attached to a heating mantle) and nitrogen inlet. The vessel was charged with perfume encapsulates (100 g, 40% active) and 130 ml of de-ionised water and the contents purged with nitrogen for 10 minutes after which point the vessel and contents were left over a nitrogen blanket for the duration of the reaction and the temperature was then raised to 70⁰C. Vinyl acetate (4 g) and LBG solution (40 ml, 1 % Active) was added. Aqueous ascorbic acid solution (0.89 g in 5g de-ionised water) together with aqueous hydrogen peroxide solution (0.35 g, 30% active in 5 g de-ionised water) was added to initiate the polymerisation. After 90 minutes the sample was then allowed to cool to room temperature under stirring. The white dispersion that was obtained consisted of -14% solids. The same method was used the PMA based polymers except that the vinyl acetate was replaced with methyl acrylate (4g).

Example 1 : without added formaldehyde scavenger

Results are shown in the table below with formaldehyde levels expressed in ppm. The capsules were aged at 37C for five weeks in fabric conditioner base.

From the results of example 1 it can be seen that there was a marked reduction in the level of formaldehyde produced on storage for all three types of capsules when the capsules were modified with a coating. It is believed that the coating protects the aminoplast portion of the capsule from the effect of the acidic rinse conditioner. It can be seem that better results are obtained with the larger capsules and it is believed that this is due to the smaller surface area available for diffusion and/or the thicker shell that will be deposited on this smaller area given that the same amount of shell was deposited. Example 2: with added formaldehyde scavenger (0.05% ethylene urea on product ):

Results are shown in the table below with formaldehyde levels expressed in ppm. The capsules were either aged at 37C for five weeks in fabric conditioner base or frozen to keep them fresh.

From the results of Example 2 it can be seen that the initial levels of formaldehyde are very much lower than in the scavenger-free samples - compare for example comparative (b) of Example 1 (50ppm) which is reduced to 6.5 ppm. On storage the scavenger containing samples rise to 59ppm while those without scavenger rise to 93 ppm (compare AGED comparative of Example 2 with AGED comparative of Example 1 ). For the modified capsules the initial level of formaldehyde is comparable in the presence of the scavenger but there is a further improvement over the unmodified capsules (compare, for example, 77ppm with the scavenger-free capsules with 52 ppm with the addition of a scavenger. The greatest level of formaldehyde generation as compared to the fresh samples was in the unmodified capsules. In both sets of modified capsules (examples 2a and 2b) less formaldehyde was generated than in the unmodified capsules.

Claims

Claims:

1. A fabric conditioning composition of pH less than 7 comprising:

a) a quaternary ammonium fabric conditioning agent,

b) an encapsulated benefit agent wherein said encapsulates are made at least part from a formaldehyde-based polymer, and, at least in part from a non-formaldehyde based polymer, and

c) a formaldehyde scavenger.

2. A composition according to claim 1 wherein the formaldehyde-based polymer is a polymer of formaldehyde and one or more of melamine, monomethylmelamine, dimethyl melamine, trimethyl melamine, monoethyl melamine, 1 -methyl-3-propyl-5-butyl melamine, 1 -phenyl melamine, urea, thiourea, dicyandiamide, melam, melon, ammeline, ammelide and guanamine.

3. A composition according to claim 1 wherein the non-formaldehyde based polymer is a polymer comprising one or more of styrene; α-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.

4. A composition according to claim 1 wherein the formaldehyde scavenger comprises one or more of a beta-dicarbonyl, mono or di-amide, amine and polyamine.

5. A composition according to claim 1 wherein the formaldehyde scavenger comprises one or more of acetoacetamide, ethyl acetoacetate, N,N-Dimethyleneacetamide, acetoacetone, dimethyl-1 ,3- acetonedicarboxylate, I .S-acetonedicarboxylic acid, malonic acid, resorcinol, 1 ,3-cyclohexadione, barbituric acid, 5,5-dimethyl-1 ,3- cyclohexanedione, 2,2-dimethyl-1 ,3-dioxane-4,6-dione, salicylic acid, methyl acetoacetate, ethyl-2-methyl acetoacetate, 3-methyl-acetoacetone, dimethyl malonate, diethyl malonate, 1 ,3-dimethyl barbituric acid, resorcinol, phloroglucinol, orcinol, 2,4-dihydroxy benzoic acid, 3,5- dihydroxy benzoic acid, urea, ethylene urea, propylene urea, caprolactam, glycouril, hydantoin, 2-oxazolidinone, 2-pyrrolidinone, uracil, thymine, uric acid, allantoin, 4,5-dihydroxyethylene urea, monomethylol-4-hydroxy-4- methoxy-5,5-dimethyl-propylurea, nylon 2-hydroxyethyl ethylene urea, 2- hydroxyethyl urea, L-citrulline, biotin, N-methyl urea, N-ethyl urea, N-butyl urea, N-phenyl urea, 4,5-dimethoxy ethylene urea, succinimide and malonamide.

6. A composition according to claim 1 wherein the encapsulated benefit agent further comprises a deposition aid selected from a polysaccharide, a dicarboxylic/polyols polymer and mixtures thereof.

7. A composition according to claim 1 wherein the polysaccharide is selected from Locust Bean Gum, cationic starch and mixtures thereof.

8. A composition according to claim 1 wherein

a) the quaternary ammonium fabric conditioning agent is selected from ditallowoyloxyethyl dimethyl ammonium chloride, dihydrogenated- tallowoyloxyethyl dimethyl ammonium chloride, ditallow dimethyl ammonium chloride, dihydrogenatedtallow dimethyl ammonium chloride, ditallowoyloxyethyl methylhydroxyethylannnnoniunn methyl sulfate, dihydrogenated-tallowoyloxyethyl methyl hydroxyethylammonium chloride or combinations thereof;

b) the encapsulated particles comprise an inner shell of the melamine/urea formaldehyde type, and, an outer shell of the vinyl acetate and/or methyl acrylate type;

c) the formaldehyde scavenger is selected from the group comprising urea, ethylene urea, ethylacetamide, acetoacetamide and mixtures thereof; and,

d) the encapsulated particles comprise a polysaccharide deposition aid selected from Locust Bean Gum, cationic starch and mixtures thereof.