EP0059502B1

EP0059502B1 - Textile treatment compositions

Info

Publication number: EP0059502B1
Application number: EP82200194A
Authority: EP
Inventors: John Christopher Turner; Anthony Dovey
Original assignee: Procter and Gamble Ltd; Procter and Gamble Co
Current assignee: Procter and Gamble Ltd; Procter and Gamble Co
Priority date: 1981-02-28
Filing date: 1982-02-18
Publication date: 1985-06-26
Also published as: ATE14027T1; DE3264359D1; JPH0215664B2; JPS57205580A; EP0059502A1; ES509979A0; IE52564B1; IE820426L; CA1206705A; GR75151B; ES8303517A1

Abstract

Aqueous textile treatment compositions comprising 2% to 11% of an active mixture comprising a water-insoluble cationic fabric softener, a water-insoluble nonionic fabric softener selected from C10-C24 non-cyclic hydrocarbons and C10-C40 fatty acid esters, and an alkoxylated ammonium surfactant having the general formula <CHEM> wherein R5 is C12-C24 alkyl or alkenyl, and R6, R7 and R8 represent C1-C4 alkyl, aryl or (CnH2nO)yH, wherein n is 2 or 3, y is from 0 to 9 and the sum total of CnH2nO groups is from 1 to 9, and wherein X is a counteranion. The compositions are stable compositions displaying excellent viscosity characteristics, softening and antistatic performance.

Description

The present invention relates to textile treatment compositions. In particular, it relates to aqueous compositions suitable for use in the rinse cycle of a textile laundering operation to provide softening/static control benefits, the compositions being characterised by excellent physical characteristics on storage.
Textile treatment compositions suitable for providing fabric softening and static control benefits during laundering are well-known in the art and have found wide scale commercial application. Conventionally, rinse-added fabric softening compositions contain, as the active softening component, substantially water-insoluble cationic materials having two long alkyl chains. Typical of such materials are di-stearyl dimethyl ammonium chloride and imidazolinium compounds substituted with two stearyl groups.
However, although the above mentioned cationic compounds are highly effective softeners when applied in a rinse solution, there are certain disadvantages associated with their use. For example, the cationic compounds having long alkyl chains are very sensitive to carry over of anionic detergent into the rinse. Thus, carry over of anionic detergent tends to neutralize the softening effect because the anionic-cationic complex tends to precipitate out of solution. Also, certain cationic surfactant compounds are expensive and in short supply and it is therefore desirable, for commercial reasons, to provide softening compositions having a reduced amount of cationic surfactant compound.
While certain water-insoluble nonionic compounds have been proposed as fabric softening agents, these are found to deposit only very inefficiently from aqueous solution because of their lack of positive charge and so they must be used in conjunction with a cationic surfactant material to act as "carrier". Such compositions containing mixtures of water-insoluble cationic and nonionic materials have to be formulated with great care to ensure that the compositions will have the necessary phase stability and viscosity characteristics over prolonged periods of storage under both low and high temperature conditions. In particular, the viscosity of the product must be neither too high as to lead to problems with pourability or gel formation, nor too low as to lead to poor consumer impression, and of course the viscosity must be stable within the appropriate range over long term storage and under varying temperature conditions.
GB-A-1550205 and GB-A-1550206 disclose the use of certain cationic surfactants for enhancing the deposition of fatty acid ester softening materials onto fabrics. US-A-4233164 and EP-A-21476 disclose the use of a protonated di-poly-ethoxy monoalkylamine containing from 10 to 40 ethylenoxy groups for improving the freeze-thaw recovery of a fabric conditioning composition containing cationic fabric conditioner and a fatty acid ester.
EP-A-18039 and US-A-4,149,978 describe fabric softening compositions containing a hydrophobic adjunct and a water-soluble cationic surfactant, especially a polyethoxylated diammonium compound. US―A―3,974,076 relates to fabric softening compositions containing a polyethoxylated quaternary ammonium compound and a fatty alcohol.
There is a continuing need, however, for textile treatment compositions having excellent soften- ing/antistatic benefits, combined with optimum viscosity and phase stability characteristics.
The present invention thus provides textile treatment composition having improved softening characteristics, particularly under hard water wash/rinse conditions, and improved formulation viscosity characteristics under long term storage together with excellent phase stability characteristics.
Accordingly, the present invention provides an aqueous textile treatment composition comprising from 2% to 11 % by weight of composition of an active mixture comprising from 1% to 10% by weight of composition of a substantially water-insoluble cationic fabric softener having the general formula I
wherein R₁ and R₂ represent alkyl or alkenyl groups of from 12 to 24 carbon atoms; R₃ and R₄ represent hydrogen or alkyl, alkenyl or hydroxyalkyl groups containing from 1 to 4 carbon atoms; and X is an equivalent amount of a counterion; and from 0.5% to 5% of a substantially water-insoluble nonionic fabric softener selected from C_l6-C₂₄ non-cyclic hydrocarbons and fatty acid esters, having a total of from 10 to 40 carbon atoms, characterized in that the active mixture additionally comprises from 0.1% to 2% by weight of composition of an alkoxylated ammonium surfactant having the general formula 11
wherein R_s is a C16-C22 alkyl or alkenyl group, n is 2, and x, y are each a number average in the range from 0 to 6, the sum total of x and y being in the range from 1 to 6, and X is as defined above.
All percentages and ratios herein are specified by weight of total composition, unless otherwise indicated.
Preferably, the textile treatment compositions contain from 2% to 8% by weight, more preferably from 2.5% to 6% by weight of the cationic fabric softener, from 0.4% to 1.5% by weight, more preferably from 0.5% to 1.2% by weight of the alkoxylated ammonium surfactant, and from 1% to 3% by weight, more preferably from 1% to 2% by weight of the nonionic fabric softener. These levels of active materials are preferred from the viewpoint of obtaining optimal product viscosity and stability characteristics.
The alkoxylated ammonium surfactant component herein has the general formula II
wherein R₅ is a C₁₆₇-C₂₂ alkyl or alkenyl group, n is 2 and x, y are each a number average in the range from 0 to 6, preferably 0 to 3, and the sum total of x and y is in the range from 1 to 6, preferably 1 to 3 and wherein X is as defined above. By'number average' is meant that x, y each represent the weight averaged number of moles of alkylene oxide in the corresponding polyoxyalkylene moiety of the surfactant.
Note that, depending on the precise pH of the textile treatment composition, the alkoxylated ammonium surfactant may be present in the composition in partially deprotonated form. In such cases, all weight percentages and ratios herein are expressed in terms of the corresponding fully protonated salt.
The compositions of the invention are generally formulated so as to have a slightly acidic pH, preferably from about 3.5 to 7, more preferably from about 4 to 6; moreover, it is desirable that the final formulation pH be lower than the acidity constant (pK_a) of the amine so that the amine exists predominantly in the form of its protonated or ammonium derivative. Physically, the compositions take the form of a particulate dispersion of the cationic and nonionic fabric softeners in an aqueous continuum containing at least some of the alkoxylated ammonium surfactant.
A highly preferred composition comprises:

(a) from 2% to 8% of the cationic fabric softener having general formula I,
(b) from 0.4% to 1.5% of the alkoxylated ammonium surfactant having general formula II wherein the weight ratio of (a) to (b) is in the range from 6:1 to 3:1,
(c) from 1% to 3% of the nonionic fabric softener wherein the weight ratio of [(a)+(b)] to
(c) is in the range from 6:1 to 1.5:1.

The nonionic fabric softener materials herein are C_IO-C₂₄ non-cyclic hydrocarbons and fatty acid esters having a total of 10 to 40 carbon atoms. A particularly preferred material is glyceryl monostearate.
The present invention also provides a method of making the textile treatment compositions generally described above by the steps of:

(a) preparing a molten premix of the water-insoluble cationic fabric softener, the water-soluble alkoxylated surfactant and the water-insoluble nonionic fabric softener,
(b) intimately mixing the molten premix with water at a temperature above the melting point of the premix to form an aqueous dispersion, and
(c) cooling the dispersion.

The compositions of the invention preferably are stable to separation in a centrifuge at 3000 r.p.min for 16 hours and have a dynamic viscosity in the range from about (0.35 Pa.s) (350 cp) to about (0.07 Pa.s) (70 cp), preferably from about (0.2 Pa.s) (200 cp) to about (0.1 Pa.s) (100 cp) measured in a Brookfield (RTM) Viscometer, using Spindle No. 2 at 60 r.p.min and at 21°C.
The various ingredients of the compositions of the invention will now be discussed in detail.
The water-insoluble cationic fabric softener is preferably a fabric-substantive cationic compound which, in pure form as a strong acid salt (e.g. chloride), has a solubility in distilled water at pH 2.5 and 20°C of less than 1 g/l, or can be a mixture of such compounds. In this context, the soluble fraction of the surfactant is taken to be that material which cannot be separated from water by centrifugal action and which passes a 100 nm Nucleopore filter (Registered Trade Mark). In addition, the cationic softener desirably has a monomer solubility (as measured by critical micelle concentration or C.M.C.) such that the C.M.C. of the material under the conditions defined above is less than about 50 p.p.min, preferably less than about 20 p.p.min. Literature C.M.C. values are taken where possible, especially surface tension, conductimetric or dye adsorption values.
The substantially water-insoluble cationic fabric softeners are the quaternary ammonium and amine salt compounds having the formula:-
wherein R₁ and R₂ represent alkyl or alkenyl groups of from 12 to 24 carbon atoms, R₃ and R₄ represent hydrogen, alkyl, alkenyl or hydroxyalkyl groups containing from 1 to 4 carbon atoms; and X is the salt counteranion, preferably selected from halide, methyl sulfate, ethyl sulfate, benzoate, acetate, propionate and phosphate 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 anionic chloride, didocosyl dimethyl ammonium chloride; di(hydrogenated tallow) _- dimethyl ammonium methyl sulfate; dihexadecyl diethyl ammonium chloride; di(coconut alkyl) dimethyl ammonium chloride, and di(coconut alkyl) dimethyl ammonium methosulfate. Of these ditallow dimethyl ammonium chloride and di(hydrogenated tallow alkyl) dimethyl ammonium chloride are preferred.
With respect to the alkoxylated ammonium surfactant component, these are defined as protonated mono- or di-polyethoxy primary alkyl amines wherein the amine contains from 16 to 22 carbon atoms in the alkyl chain, and wherein the average number of ethoxy groups per polyethoxy chain is from 0 to 6, preferably from 0 to 3, and wherein the sum total of polyethoxy groups per molecule is from 1 to 6, preferably from 1 to 3. Highly preferred amines have an alkyl group derived from hardened or unhardened tallow or stearyl and are ethoxylated with an average of about 2 moles of ethylene oxide per mole of amine (referring to Formula II, x=y=₁).
Preferred water-insoluble nonionic fabric softeners of the fatty acid ester class are C,_o-C₂₄ fatty acid esters of mono- or poly-hydroxy alcohols containing 1 to 12 carbon atoms. Preferably the alcohol has from 1 to 8 carbon atoms, and the fatty acid ester has at least 1, more preferably at least 2, free (i.e., unesterfied) hydroxyl groups.
The mono or poly-hydric alcohol portion of the ester can be represented by methanol, isobutanol, 2-ethyl-hexanol, isopropanol, ethylene glycol and polyethylene glycol with a maximum of 5 ethylene glycol units, glycerol, diglycerol, polyglycerol, xylitol, erythritol, pentaerythritol, sorbitol or sorbitan, sugars such as glucose, fructose, galactose, mannose, xylose, arabinose, ribose, 2-deoxy-ribose, sedoheptulose and sucrose. Ethylene glycol, glycerol, and sorbitan esters are particularly preferred, especially the monoesters of glycerol.
The fatty acid portion of the ester normally comprises a fatty acid having from 10 to 24 (preferably 12 to 22) carbon atoms, typical examples being lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, oleic acid and linoleic acid.
The glycerol esters are very highly preferred. These are the mono-, di- or tri-esters of glycerol and fatty acids of the class described above. Commercial glyceryl mono-stearate, which may contain a proportion of di- and tri-stearate, is suitable. Also useful are mixtures of saturated and unsaturated esters of glycerol derived from mixed saturated and unsaturated fatty acids.
Another suitable group of nonionic fabric conditioning agents are the C₁₀ to C₂₄ fatty acid esters of sorbitan such as those described in US―A― 4,085,052. Sorbitan mono- and di-esters of lauric, myristic, palmitic, stearic, arachidic or behenic, oleic or linoleic acids are particularly useful as softening agents and can also provide antistatic benefits. Sorbitan esters are commercially available, for instance, under the trade name Span (RTM). For the purpose of the present invention, it is preferred that a significant amount of di- and tri-sorbitan esters are present in the ester mixture. Ester mixtures having from 20%-50% mono-ester, 25%-50% di-ester and 10%-35% of tri- and tetra-esters are preferred.
Preferred nonionic fabric softeners of the hydrocarbon class are paraffins or olefins containing from 14 to 22 carbon atoms. Materials known generally as paraffin oil, soft paraffin wax and petrolatum are especially suitable. Examples of specific materials are tetradecane, hexadecane, octadecane and octadecene. Preferred commercially-available paraffin mixtures include spindle oil and light oil, technical grade mixtures of C₁₄/C₁₇ n-paraffins and C₁₈/C₂₀ n-paraffins and refined white oil.
In addition to the cationic softener, nonionic softener, and alkoxylated ammonium surfactant components, the present compositions can be supplemented by all manner of optional components conventionally used in textile treatment compositions, for example, colorants, perfumes, preservatives, optical brighteners, opacifiers, pH buffers, viscosity modifiers, fabric conditioning agents, surfactants, stabilizers, such as guar gum and polyethylene glycol, anti-shrinkage agents, anti-wrinkle agents, fabric crisping agents, nonionic softening agents, spotting agents, soil- release agents, germicides, fungicides, antioxidants such as butylated hydroxy toluene, anti-corrosion agents etc. Of course, the level of these optional ingredients should, if necessary, be controlled so as not to deleteriously effect the physical stability and viscosity characteristics of the product.
Another optional ingredient is a water-soluble non-alkoxylated quaternary ammonium surfactant having the general formula III
wherein Rg represents a C₈-C₂₄ alkyl or alkenyl group, and R_io, R₁₁, R₁₂ independently represent a C_1-C₄ alkyl or alkenyl group or an aryl group and wherein X is as defined earlier.
Suitable materials of this general type include the tallow trimethyl ammonium salts, cetyl trimethyl ammonium salts, myristyl trimethyl ammonium salts and coconutalkyl trimethyl ammonium salts.
In addition to the above-mentioned components, the compositions may contain other textile treatment or conditioning agents. Such agents include silicones, as for example described in DE-A-2631 419. The optional silicone component can be used in an amount of from 0.1 % to 6%, preferably from 0.2% to 2% of the softener composition.
Another optional ingredient of the present compositions is a water-soluble cationic polymer having a molecular weight in the range from 2000 to 250,000, preferably from 5000 to 150,000 and containing an average of from 100 to 1000, preferably from about 150 to 700 monomer units per molecule. Molecular weights are specified as viscosity average molecular weights and can be determined as described in F. Daniels et al Experimental Physical Chemistry, pp. 71-74, 242-246, McGraw-Hill (1949), at 25°C using an Ostwald viscometer. The polymers are preferably soluble in distilled water to the extent of 0.5% by weight at 20°C. Such polymers can provide valuable softening robustness in the presence of anionic surfactant carried over from a previous cleaning operation, and also contribute to viscosity control. Suitable polymers of this type include polyethyleneimine having an average molecular weight of from 10,000 to 35,000, ethoxylated polyethyleneimine wherein the weight ratio of polyethyleneimine to ethyleneoxide is at least 1:1 and wherein the molecular weight is from 20,000 to 70,000, and quaternised polyethyleneimines sold under the Trade Name Alcostat (RTM) by Allied Colloids.
Suitable preservatives for use in the present compositions include 2-nitro-2-bromo-propane-1,3-diol, glutaraldehyde and 2-methyl-4-isothiazolin-3-one and its 5-chloro derivative.
The textile treatment compositions of the invention can be used by adding to the rinse cycle of a conventional home laundry operation. Generally, rinse water has a temperature of from 5°C to 60°C. The concentration of the total active ingredients is generally from 2 ppm to 1000 ppm, preferably from 10 ppm to 500 ppm, by weight of the aqueous rinsing bath.
The following examples illustrate the invention. In the Examples, the following abbreviations are used:

Examples I to III

Aqueous textile treatment compositions are prepared having the following formulae:-
The compositions are prepared by forming a molten premix of the water-insoluble cationic and nonionic fabric softeners and alkoxylated ammonium surfactants, and where present, silicone and non-alkoxylated water-soluble surfactant, at a temperature of about 65°C. The molten premix is then injected into a water seat containing minor ingredients, apart from perfume, held at about 45°C and this is stirred for about 5 minutes. Thereafter, the dispersion is passed through a heat exchanger to bring the temperature down to about 25°C and finally perfume is added.
The products thus prepared are stable dispersions displaying excellent viscosity characteristics at both low and high temperatures over prolonged periods of storage; they deliver excellent softening and antistatic performance across the range of natural and synthetic fabrics in both hard and soft water and they also display excellent dispensing and dissolving characteristics in cold rinse water.

Claims

1. An aqueous textile treatment composition comprising from 2% to 11% by weight of composition of an active mixture comprising

from 1% to 10% by weight of composition of a substantially water-insoluble cationic fabric softener having the general formula I

wherein R₁ and R₂ represent alkyl or alkenyl groups of from 12 to 24 carbon atoms; R₃ and R₄ represent hydrogen or alkyl, alkenyl or hydroxyalkyl groups containing from 1 to 4 carbon atoms; and X is an equivalent amount of a counteranion; and from 0.5% to 5% by weight of composition of a substantially water-insoluble nonionic fabric softener selected from C₁₀―C₂₄ non-cyclic hydrocarbons and fatty acid esters having a total of from 10 to 40 carbon atoms, characterized in that the active mixture additionally comprises from 0.1% to 2% by weight of composition of an alkoxylated ammonium surfactant having the general formula II

wherein R_s is a C₁₆-C₂₂ alkyl or alkenyl group, n is 2, and x, y are each a number average in the range from 0 to 6, the sum total of x and y being in the range from 1 to 6, and X is as defined above.

2. A composition according to Claim 1 characterized by from 2% to 8% by weight of composition of the cationic fabric softener having general formula 1.

3. A composition according to Claim 1 or 2 characterized by from 0.4% to 1.5% by weight of composition of the alkoxylated ammonium surfactant having general formula II.

4. A composition according to any of Claims 1 to 3 characterized by from 1 % to 3% by weight of composition of the nonionic fabric softener.

5. A composition according to any of Claims 1 to 4 characterized in that x, y are each a number average in the range from 0 to 3, the sum total of x and y being in the range from 1 to 3.

6. A composition according to any of Claims 1 to 5 characterized in that the nonionic softening agent is glyceryl monostearate.

7. A composition according to any of Claims 1 to 6 characterized by:

(a) from 2% to 8% of the cationic fabric softener having the general formula I,

(b) from 0.4% to 1.5% of the alkoxylated ammonium surfactant having general formula II wherein the weight ratio of (a) to (b) is in the range from 6:1 to 3:1,

(c) from 1% to 3% of the nonionic fabric softener wherein the weight ratio of [(a)+(b)] to

(c) is in the range from 6:1 to 1.5:1.