Fabric softening composition.

The present invention relates to a fabric softening composition. In particular but not exclusively it relates to an aqueous based concentrated fabric softening composition.

Fabric softening compositions for the treatment of fabrics, particularly after washing, to improve the feel of the fabrics and, in the case of clothes, to improve the comfort in wear, conventionally include cationic fabric softening agents.

It is known from European patent specification Nos EP-A-86104, 86105, 86106 and 88520 (UNILEVER) that the softening performance of such compositions, their manufacture, ease of use and physical properties can be improved, particularly where the composition is in the form of a concentrated aqueous- based product, by the inclusion in the composition of lanolin or a lanolin-like material.

We have now surprisingly found that the properties of such compositions can be maintained if a part of the lanolin or lanolin-like material is replaced by specific alkoxylated nonionic materials.

Thus, according to the invention, there is provided a fabric softening composition comprising a water-insoluble cationic fabric softener, lanolin or a lanolin-like material and an alkylene oxide adduct of a fatty compound selected from fatty alcohols, fatty acids, fatty esters, fatty amines and fatty acid amides, the fatty compound containing at least 10 carbon atoms and the adduct containing an average of not more than 7 alkylene oxide groups per molecule.

The composition may take the form of a solid product, containing the cationic softener, the lanolin or lanolin-like material, the alkoxylated nonionic material and optionally a carrier material which should ideally be a water-soluble or -dispersible material such as urea or sodium sulphate. More usually however, the composition will take the form of a liquid product, containing the cationic softener, the lanolin or lanolin-like material, the alkoxylated nonionic material and an aqueous base.

The weight ratio of the cationic softener to the sum of the lanolin or lanolin-like material and the alkoxylated nonionic material is preferably from 20:1 to 1:20, most preferably from about 10:1 to about 1:10. The weight ratio of the lanolin or lanolin-like material to the alkoxylated nonionic material is preferably from 10:1 to 1:10.

When the composition is in liquid form, it preferably comprises at least about 0.5% by weight of the cationic fabric softener, most preferably at least about 2% by weight. The benefits of the invention are most useful in concentrated products containing at least about 8% cationic fabric softener. When in liquid form the composition will not usually contain more than about 36% by weight cationic softener, most preferably not more than about 25% by weight.

The water-insoluble cationic fabric softener can be any fabric-substantive cationic compound which has a solubility in water at pH 2.5 and 20°C of less than 10 g/l. Highly preferred materials are quaternary ammonium salts having two C₁₂-C₂₄ alkyl or alkenyl chains, optionally substituted or interrupted by functional groups such as -OH, -O-, -CONH, -COO-, etc.

Well known species of substantially water-insoluble quaternary ammonium compounds have the formula <chemistry id="chem0001" num="0001"><img file="EP0159918A2_D0001.tif" /></chemistry>wherein R₁ and R₂ represent hydrocarbyl groups from about 12 to about 24 carbon atoms; R₃ and R₄ represent hydrocarbyl groups containing from 1 to about 4 carbon atoms; and X is an anion, preferably selected from halide, methyl sulfate and ethyl sulfate radicals. Representative examples of these quaternary softeners include ditallow dimethyl ammonium chloride; ditallow dimethyl ammonium methyl sulfate; dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow alkyl) dimethyl ammonium chloride; dioctadecyl dimethyl ammonium chloride; dieicosyl dimethyl ammonium chloride; didocosyl dimethyl ammonium chloride; di(hydrogenated tallow) dimethyl ammonium methyl sulfate; dihexadecyl diethyl ammonium chloride; di(coconut alkyl) dimethyl ammonium chloride. Ditallow dimethyl ammonium chloride, di(hydrogenated tallow alkyl) dimethyl ammonium chloride, di(coconut alkyl) dimethyl ammonium chloride and di(coconut alkyl) dimethyl ammonium methosulfate are preferred.

Another class of preferred water-insoluble cationic materials are the alkylimidazolinium salts believed to have the formula: <chemistry id="chem0002" num="0002"><img file="EP0159918A2_D0002.tif" /></chemistry>wherein R₆ is an alkyl or hydroxyalkyl group containing from 1 to 4, preferably 1 or 2 carbon atoms, R₇ is an alkyl or alkenyl group containing from 8 to 25 carbon atoms, R₈ is an alkyl or alkenyl group containing from 8 to 25 carbon atoms, and R₉ is hydrogen or an alkyl containing from 1 to 4 carbon atoms and A is an anion, preferably a halide, methosulfate or ethosulfate. Preferred imidazolinium salts include 1-methyl-1-(tallowylamido-) ethyl -2-tallowyl- 4,5-dihydro imidazolinium methosulfate and 1-methyl-1-(palmitoylamido)ethyl -2-octadecyl-4,5- dihydro- imidazolinium chloride. Other useful imidazolinium materials are 2-heptadecyl-l-methyl-l- (2-stearylamido)-ethyl-imidazolinium chloride and 2-lauryl-l-hydroxyethyl-1-oleyl-imidazolinium chloride. Also suitable herein are the imidazolinium fabric softening components of US Patent No 4 127 489, incorporated by reference.

Representative commercially available materials of the above classes are the quaternary ammonium compounds Arquad 2HT (ex AKZO); Noramium M2SH (ex CEKA); Aliquat-2HT (Trade Mark of General Mills Inc) and the imidazolinium compounds Varisoft 475 (Trade Mark of Sherex Company, Columbus Ohio) and Rewoquat W 7500 (Trade Mark of REWO).

An essential component of the present invention is lanolin or a lanolin-like material. Lanolin is wool wax which has been purified by various purification steps including washing, neutralisation, filtration, bleaching and deodorisation. Lanolin is composed primarily of esters which constitute the active constituents in the present invention and which yield on hydrolysis a mixture of complex alcohols and fatty acids. The alcohols which form about half of the ester component by weight, include sterols and terpene alcohols. The sterols amount to about 30% and include cholesterol, 7-dehydrocholesterol and cerebosterol and dihydrocholesterol (cholestanol). The terpene alcohols include lanesterol (C₃₀H₅₀O), dihydrolanesterol (C₃₀H₅₂0), a^gno^sterol (C30H480), dihydroagnosterol (C30H500).

Lanolin is available commercially in a number of forms. Lanolin as such contains the active constituents primarily in their ester form. It is also available in two hydrolysed forms where the active constituents are primarily in their alcoholic or carboxylic acid form. Further, lanolin may be hydrogenated to form a product where the active constituents are present primarily only in their alcoholic form. Lanolin is also commercially available in propoxylated and acetylated forms. As used herein the term "lanolin" is intended to refer to any such material derived from wool wax whether the active constituents are in the alcoholic, ester, alkoxylated, hydrogenated of other chemical form.

Suitable commercial forms of lanolin include Corona (lanolin BP), Hartolan, Polychol and Coronet (Trade Marks of Croda Chemicals Ltd), Solulan, Acetulan and Modulan (Trade Marks of American Cholesterol Products Inc) and Lanocerina (Trade Mark - Esperis SpA Milan). Commercial lanolin is also available from Westbrook Lanolin Co., Bradford, England.

Many of the active constituents of lanolin can be prepared synthetically, from sources other than wool wax or can be extracted from wool wax and other naturally occurring material. While for cost reasons the commercially available forms of lanolin are preferred for the present invention, it is also possible to use any one or more of the active constituents referred to above however derived, and also materials of similar structure. Thus, in place of lanolin one may use a "lanolin-like material- which term as used herein includes <ul id="ul0001" list-style="none"><li>(a) any one or more of the active lanolin constituents referred to above, and the carboxylic acid or alcohol, derivatives thereof;</li><li>(b) the corresponding carboxylic acids or alcohols and ester derivatives of the materials listed in (a), in particular the esters thereof with fatty acids or alcohols containing at least 12 carbon atoms;</li><li>(c) iso- and anteiso-alcohols and acids and derivatives thereof having the general formula <chemistry id="chem0003" num="0003"><img file="EP0159918A2_D0003.tif" /></chemistry>where R¹ is a divalent straight or branched chain, saturated or unsaturated, substituted or unsubstituted hydrocarbyl group having at least 7, preferably at least 15 carbon atoms, R² is a methyl or ethyl group and X is --OH,--COOH,--O--C--R3 or O --_COOR³ where _R³ is a hydrocarbyl group, in particular a fatty acid alkyl group containing at least 12 carbon atoms. Examples of materials in this group include 16-methyl heptadecanol, 24-methylhexacosanol, 8-methyl nonanoic acid; and 2-hydroxy-26-methyl heptadecanoic acid.</li></ul>

The level of lanolin or lanolin-like material in the compositions of the invention, when in liquid form, is preferably from 0.25% to about 10% by weight, most preferably from about 0.35% to about 5% by weight.

The alkoxylated nonionic material is an alkylene oxide adduct of various fatty compounds as specified above.

Alkylene oxide adducts of fatty alcohols useful in the present invention, preferably have the general formula: <chemistry id="chem0004" num="0004"><img file="EP0159918A2_D0004.tif" /></chemistry>wherein R¹⁰ is an alkyl or alkenyl group having at least 10 carbon atoms, most preferably from 10 to 22 carbon atoms, y most preferably is not more than 4.0, such as from about 0.5 to about 3.5 and n is 2 or 3. Examples of such materials include Synperonic A3 (ex ICI) which is a C₁₃-C₁₅ alcohol with about three ethylene oxide groups per molecule and Empilan KB3 (ex Marchon) which is lauric alcohol 3EO.

Alkylene oxide adducts of fatty acids useful in the present invention, preferably have the general formula <chemistry id="chem0005" num="0005"><img file="EP0159918A2_D0005.tif" /></chemistry>wherein R¹⁰, n and y are as given above. Suitable examples include ESONAL 0334 (ex Diamond Shamrock) which is a tallow fatty acid with about 2.4 ethylene oxide groups per molecule.

Alkylene oxide adducts of fatty esters useful in the present invention include adducts of mono-, di- or tri-esters of polyhydric alcohols containing 1 to 4 carbon atoms; such as coconut or tallow oil (triglyceride) 3EO (ex Stearine Dubois).

Alkylene oxide adducts of fatty amines useful in the present invention, preferably have the general formula <chemistry id="chem0006" num="0006"><img file="EP0159918A2_D0006.tif" /></chemistry>wherein R and n are as given above, and x and z in total are preferably not more than 4.0, most preferably from about 0.5 to about 3.5. Examples of such materials include Ethomeen T12 (tallow amine 2EO, available from AKZO), Optamine PC5 (coconut alkyl amine 5EO) and Crodamet 1.02 (oleylamine 2EO, available from Croda Chemicals).

Alkylene oxide adducts of fatty amides useful in the present invention, preferably have the general formula <chemistry id="chem0007" num="0007"><img file="EP0159918A2_D0007.tif" /></chemistry>wherein _R¹⁰ and n are as given above, and x and z in total are preferably not more than 4.0, such as from about 0.5 to about 3.5 while one of x and z can be zero. Examples of such materials include tallow monoethanol-amide and diethanolamide, and the corresponding coconut and soya compounds.

The viscosity of the product, when measured at 110 sec ¹ shear rate should be less than about 150 cP, preferably between about 20 and about 100 cP and the product can be added as such to a fabric rinse liquor or may be pre-diluted with water.

Preferably, the compositions of the invention contain substantially no anionic material, in particular no anionic surface active materials. If such materials are present, the weight ratio of the cationic material to the anionic material should preferably be more than 10:1, such as more than 100:1.

The compositions may include electrolytes to assist in controlling the viscosity of the product. A suitable electrolyte level in the compositions when in liquid form is from about 0.01% to about 0.5%, most preferably from about 0.02% to about 0.2%, measured as the anhydrous salt. Examples of suitable materials include lithium chloride, sodium chloride, ammonium chloride, sodium methosulphate, sodium benzoate, calcium chloride, magnesium chloride or aluminium chloride or aluminium chlorhydrate. Of these, sodium salts are less preferred.

The compositions may include low levels of solvents for the cationic fabric softener. Indeed, the cationic raw materials will often include isopropanol as a solvent. When the composition is in liquid form, it is preferred that the level of isopropanol or any other C1-C4 monohydric alcohol in the composition is less than about 10% by weight, most preferably less than about 5% by weight.

Additionally, when the composition is in liquid form, it can contain substances for maintaining the stability of the product on cold storage. Examples of such substances include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerol and polyethylene glycol. A suitable level for such materials is from about 0.5% to about 5%, preferably about 1.0% to 2.0% by weight.

The compositions of the invention may further include other additional ingredients including colourants, perfumes, preservations, anti-foams, optical brighteners, opacifiers, pH buffers (the preferred pH for the compositions in liquid form is between about 3 and about 8, such as from about 4 to about 6), further viscosity modifiers, non-cationic fabric conditioning agents, anti-shrinkage agents, anti-wrinkle agents, fabric crisping agents, spotting agents, soil-release agents, germicides, anti-oxidants and anti-corrosion agents.

The compositions of the invention may be prepared by a variety of methods. One suitable method for forming liquid products is to form a molten mixture of the cationic fabric softener, the lanolin or lanolin-like material and the alkoxylated nonionic material, add this molten mixture to water with stirring to form a dispersion and thereafter add any optional ingredients.

The invention will now be illustrated by the following Examples, where all parts and percentages are by weight. Where commercially available materials are referred to, the percentages quoted are of the active ingredients therein. Viscosities were measured in a Haake Rotoviscometer (Model RV2) at 110 sec 1 at 25°C.

EXAMPLES 1 TO 4

Rinse conditioners were prepared according to the following formulations by making a liquid mixture of the cationic softener, lanolin and the alkoxylated nonionic material, adding this mixture to water at the same temperature, and thereafter adding any remaining ingredients. The compositions were made in batches of 100g. The dispersion was formed by stirring for 7 minutes at 500 rpm. <tables id="tabl0001" num="0001"><img file="EP0159918A2_D0008.tif" /></tables>

Similar results were obtained when the TMEA was replaced with coco or palm monoethanolamides.

EXAMPLES 5 TO 8

Rinse conditioners were prepared in the same manner to that used in Examples 1 to 4 according to the following formulations. <tables id="tabl0002" num="0002"><img file="EP0159918A2_D0009.tif" /></tables>