EP0387064A2

EP0387064A2 - Fabric conditioning

Info

Publication number: EP0387064A2
Application number: EP19900302491
Authority: EP
Inventors: Stephen Norman Kay
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 1989-03-10
Filing date: 1990-03-08
Publication date: 1990-09-12
Also published as: CA2011577A1; EP0387064A3; GB8905552D0

Abstract

A liquid fabric conditioner composition comprising an aqueous base, a cationic fabric softener material and ethylene glycol distearate. Preferably the composition also comprises a fatty acid material. The ethylene glycol distearate is preferably present as a separate dispersed phase.

Description

The present invention relates to a fabric conditioning composition and a method for its preparation. Specifically the present invention relates to a fabric softener compostion for use in the rinse step of a fabric washing process.
It is known to treat fabrics, particularly after washing, with fabric softening agents in order to improve the feel of the fabrics and, in case of clothes, to improve the comfort in wear. Traditionally fabric softening agents are applied from an aqueous liquor which is made up by adding a relatively small volume of softening composition to water, for example during the rinse cycle in an automatic washing machine. The fabric softening composition is usually a cationic fabric softening agent which is a quaternary ammonium or imidazolinium salt.
It has previously been suggested to combine cationic softening materials with nonionic softening agents in fabric conditioning compositions. The use of nonionic materials in these systems is especially preferred for environmental reasons.
It is an object of the present invention to provide fabric conditioning compositions, providing increased softening benefits. Other objects of the present invention are to provide a fabric conditioning composition which is stable, easy to prepare and which has a particularly attractive appearance.
Surprisingly it has been found that one or more of the above mentioned objects can be fullfilled by using a combination of a cationic fabric softener and a specific nonionic ingredient.
Accordingly the present invention relates to a liquid fabric conditioner composition, comprising:

(i) an aqueous base;
(ii) a cationic fabric softener material; and
(iii) ethylene glycol distearate.

Surprisingly it has been found that the combined use of ethylene glycol distearate and a cationic fabric softener material provides excellent softening results. Furthermore compositions according to the invention are stable, easy to prepare and have a particularly attractive appearance.
These advantages are even more apparent when ethylene glycol distearate is used in combination with a cationic fabric softener material and a fatty acid component. Accordingly a preferred fabric conditioning composition according to the present invention comprises:

(i) an aqueous base
(ii) a cationic fabric softener material;
(iii) a fatty acid material; and
(iv) ethylene glycol distearate.

Aqueous fabric conditioning compositions generally comprise a dispersed phase of the active materials, such a phase can for instance be prepared by co-melting the active materials followed by mixing the co-melt under stirring into water. Compositions according to the present invention may contain the ethylene glycol distearate component as part of the cationic dispersed phase. Surprisingly, however, it has been found that one or more of the above mentioned advantages are even more pronounced, when the ethylene glycol distearate is present as a separate dispersed phase in the composition. Especially the appearance of the composition takes advantage of the presence of such a separate dispersed phase.
In the preparation of a fabric softening composition, the formation of a separate dispersed phase for the ethylene glycol distearate may for instance be effected by adding the ethylene glycol distearate in the form of a separate predispersion, after the forming of the first dispersed phase of other active materials.

Detailed description of the invention

Preferably the cationic fabric softener material for use in compositions according to the present invention is a cationic material which is water-insoluble in that these materials have a solubility in water at pH 2.5 and 20°C of less than 10 g/l. Highly preferred materials are cationic quaternary ammonium salts having two C12-24 hydrocarbyl chains.
Well-known species of substantially water-insoluble quaternary ammonium compounds have the formula
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) dimethyl ammonium methyl sulfate; dihexadecyl diethyl ammonium chloride; di(coconut) dimethyl ammonium chloride. Ditallow dimethyl ammonium chloride, di(hydrogenated tallow) dimethyl ammonium chloride, di(coconut) dimethyl ammonium chloride and di(coconut) dimethyl ammonium methosulfate are preferred.
Suitable materials also include dialkyl ethoxyl methyl ammonium methosulphate based on soft fatty acid, dialkyl ethoxyl methyl ammonium methosulphate based on hard fatty acid, and a material in which R₃ and R₄ represent methyl, R₁ is C₁₃₋₁₅, R₂ is CH₂CH₂OCOR, where R is stearyl, and X is methosulphate. Materials in which R₂, R₃ and R₄ each represent methyl, R₁ is the group
where R is hardened tallow and X is methosulphate are also suitable. 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.
Other preferred cationic compounds include those materials as disclosed in EP 239,910 (P&G), which is included herein by reference.
In this specification the expression hydrocarbyl group refers to alkyl or alkenyl groups optionally substituted or interrupted by functional groups such as -OH, -O-, -CONH, -COO-, etc.
Other preferred materials are the matarials of formula
R₅ being partially hardened tallow, which is available from Stepan under the tradename Stepantex VRH 90
and
where R₈, R₉ and R₁₀ are each alkyl or hydroxyalkyl groups containing from 1 to 4 carbon atoms, or a benzyl group. R₆ and R₇ are each an alkyl or alkenyl chain containing from 11 to 23 carbon atoms, and X⁻ is a water soluble anion, substantially free of the corresponding monoester.
Another class of preferred water-insoluble cationic materials are the hydrocarbylimidazolinium salts believed to have the formula:
wherein R₁₃ is a hydrocarbyl group containing from 1 to 4, preferably 1 or 2 carbon atoms, R₁₁ is a hydrocarbyl group containing from 8 to 25 carbon atoms, R₁₄ is an hydrocarbyl group containing from 8 to 25 carbon atoms and R₁₂ is hydrogen or an hydrocarbyl 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- dihydroimidazolinium chloride. Other useful imidazolinium materials are 2-heptadecyl-1-methyl-1- (2-stearylamido)-ethyl-imidazolinium chloride and 2-lauryl-1-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 CECA); Aliquat-2HT (Trade Mark of General Mills Inc), Stepantex Q185 (ex Stepan); Stepantex VP85 (ex Stepan); Stepantex VRH90 (ex Stepan); Synprolam FS (ex ICI) and the imidazolinium compounds Varisoft 475 (Trade Mark of Sherex Company, Columbus Ohio) and Rewoquat W7500 (Trade Mark of REWO).
Preferably the amount of cationic fabric softening agents in compositions according to the present invention is more than 0.5% by weight, more preferred more than 1% by weight, especially preferred more than 3% by weight of the composition. The level of cationic fabric softening materials is preferably less than 60 % by weight, more preferred less than 35 % by weight, especially preferred less than 25 % by weight.
Typical diluted products according to the present invention will for instance include from 2-15%, especially from 3-10 % by weight of cationic fabric softener materials. Concentrated products according to the present invention may contain higher levels of actives, typical levels of cationic material in these products will be from 8-30%, especially from 10 to 25%.
The ethyleneglycol distearate ingredient of compositions according to the present invention can be added as such; in that case the compositions according to the invention are preferably heated above the melting temperature of the ethyleneglycol distearate to allow the formation of ethyleneglycol distearate crystals upon cooling. These crystals are believed especially to be advantageous as far as the appearance of the product is concerned.
Especially preferred is the addition of the ethyleneglycol distearate component in the form of a predispersion, this generally avoids the need of heating the product above the melting temperature of the ethylene glycol distearate while still providing the appearance advantages.
The predispersion of ethylene glycol distearate is preferably of cationic or nonionic nature. Examples of cationic/nonionic predispersions are for instance disclosed in DE 34 11 328 (Hoechst AG) and DE 35 19 080 (Henkel KGaA).
The amount of ethylene glycol distearate in compositions according to the present invention is preferably such that the weight ratio of cationic fabric softening material to ethyleneglycol distearate is between 100:1 and 1:1, more preferably between 25:1 and 2:1, especially preferred between 20:1 and 5:1.
The level of ethylene glycol distearate is preferably above 0.1% by weight, more preferred above 0.2% by weight, especially preferred above 0.3% by weight of the composition. For reasons of costs and stability the level of ethylene glycol distearate is preferably not above 10%, more preferred not more than 5%, most preferred not more than 2.5% by weight of the composition.
Typical products according to the present invention may for instance comprise from 0.2 to 2 %, more preferred from 0.3 to 1.5% by weight of ethylene glycol distearate.
Compositions according to the present invention preferably also comprise a fatty acid component. Especially suitable combinations of fatty acid and cationic softening materials are disclosed in DE 29 43 606 (Unilever N.V.). Typical blends of cationic materials and fatty acids suitable for being used in conjunction with ethylene glycol distearate in compositions according to the present invention include 20-95 mole % of a cationic softening material and 5-80 mole % of a fatty acid material.
Preferably the fatty acid material is a C₈-C₂₄ fatty acid material, preferably saturated fatty acid materials such as hardened fatty acid are used.
The level of fatty acid material is preferably from 0.1 to 30 % by weight, more preferred from 0.2 to 15 % by weight, especially preferred between 0.3 and 7.5 % by weight, most preferred between 0.4 and 4 % by weight of the composition.

Optional ingredients

Preferably, the compositions of the present invention contain substantially no anionic material, in particular no anionic surface active material. If such materials are present, the weight ratio of the cationic fabric softening agent to the anionic material should preferably be more than 5:1.
The composition can also contain one or more optional ingredients selected from non-aqueous solvents such as C₁-C₄ alkanols and polyhydric alcohols, pH buffering agents such as strong or weak acids eg. HCl, H₂SO₄, phosphoric, benzoic or citric acids (the pH of the liquid compositions is preferably less than 5.0), rewetting agents, viscosity modifiers such as electrolytes, for example calcium chloride, antigelling agents, perfumes, perfume carriers, fluorescers, colourants, hydrotropes, antifoaming agents, antiredeposition agents, enzymes, optical brightening agents, opacifiers, stabilisers such as guar gum and polyethylene glycol, emulsifiers, anti-shrinking agents, anti-wrinkle agents, fabric crisping agents, anti-spotting agents, soil-release agents, germicides, linear or branched silicones, fungicides, anti-oxidants, anti-corrosion agents, preservatives such as Bronopol (Trade Mark), a commercially available form of 2-bromo-2-nitropropane-1,3-diol, dyes, bleaches and bleach precursors, drape imparting agents, antistatic agents and ironing aids.
Especially preferred is the addition of polymer thickener materials for viscosity regulation of the composition. Suitable polymeric materials for use in compositions according to the present invention are described in our co-pending application EP 89 200434.2 and include for instance the Natrosol Plus materials ex Hercules; other suitable materials are described in our co pending British patent application 89 04 749.2, examples of these materials are the UCAR materials ex Union Carbide.
The optional ingredients, if added, are each present at levels up to 5% by weight of the composition. The pH of the composition is preferably 5 or below, or adjusted thereto.
Anti redeposition agents particularly preferred in the compositions according to the invention are polymers. Suitable polymers include alkyl and hydroxoyalkyl cellulose ethers, such as methyl cellulose, and polyvinylpyrrolidone.
Silicones can be included in the compositions as the ironing aid, rewetting agent or the antifoaming agent. Suitable silicones for use in the compositions according to the invention include predominantly linear polydialkyl or alkylaryl siloxanes in which the alkyl groups contain one to five carbon atoms. The siloxanes can be amido or amino substituted. When the siloxane is amine substituted the amine group may be quaternised.
Compositions according to the present invention may be prepared by a variety of methods. For example a suitable method for preparing the compositions involves the premelting of the cationic softener and the ethylene glycol distearate, followed by dispersing the premelt in water of elevated temperature, optionally further diluting and cooling to ambient temperature.
As described above preferably compositions according to the invention are prepared by the addition of the ethylene glycol distearate in predispersed form. This predispersion may be added before or after formation of a dispersion of the cationic softening material. Most preferred however is a method of preparing an aqueous liquid fabric conditioning composition according to the present invention which method comprises the steps of:

(i) forming a first dispersion in water, wherein the dispersed phase comprises the cationic softening material; and
(ii) adding a pre-dispersion of ethylene glycol distearate to this first dispersed phase.

Preferably the formation of the first dispersion takes place at elevated temperature (preferably above the melting point of the materials of the first dispersed phase, typically above 50 ⁰C), followed by cooling the first dispersion to ambient temperature and subsequently addding the pre-dispersion of ethylene glycol distearate.
In use, the fabric conditioning composition of the invention may be added to a large volume of water to form a liquor with which the fabrics to be treated are contacted. Generally, the total concentration of the cationic fabric softening agent in this liquor will be between about 30 ppm and 500 ppm. The weight ratio of the fabrics to liquor will generally be between 40:1 and 4:1.
The invention will be further illustrated by means of the following examples, examples I,II and IV are included for comparison.

EXAMPLES I - VI

Fabric conditioning compositions were prepared by preheating the cationic softener materials, the fatty component and if present the silicone component at 50 ^oC followed by stirring the pre-melt into water of ambient temperature and diluting and cooling the obtained dispersion to the required active level. In examples 3,5 and 6 an ethylene glycol distearate predispersion (S3550/1 ex Hoechst) of 14 % ethylene glycol distearate (EGDS) stabilised with coconutmonoethanolamide (CEA) and alcoholethoxylate (AEO) in weight ratios EGDS:CEA:AEO of 16:5:1 was postdosed to the composition at ambient temperature. The pH of the composition was adjusted with orthophosphoric acid to 2.8.

EXAMPLE	I	II	III	IV	V	VI
COMPONENT	% BY WEIGHT
ARQUAD 2HT	4.8	4.8	4.8	5.2	5.2	5.2
FATTY ACID (a)	0.5	0.5	0.5	0.5	0.5	0.5
PDMS (b)	-	0.13	0.13	-	-	-
EGDS	-	-	0.4	-	0.4	0.6
CEA	-	-	0.13	-	0.13	0.19
AEO	-	-	0.03	-	0.03	0.04
OPA (c)	to a pH of 2.8
dye,water	balance

(a) coconut fatty acid
(b) polydimethylsiloxane
(c) orthophosphoric acid

Compositions III,V and VI had an attractive pink silky appearance, which was significantly better than the appearance of compositions I,II and IV which were blue.
Pieces of cotton terry towelling were rinsed in approximately 20 l of water in a front loading automatic machine whereto 90 g of one of the above softening compositions was added, and subsequently line dried. Each assessment was done for four machines and the cloths were afterwards assessed by a trained panel, a higher softness score indicating better softness. The following results were obtained:

COMPOSITION I II III IV V VI

softening score 4.5 5.5 8.0 3.5 6.75 7.75

Claims

1. A liquid fabric conditioner composition, comprising:

(i) an aqueous base;

(ii) a cationic fabric softener material; and

(iii) ethylene glycol distearate.

2. A composition according to claim 1, comprising

(i) an aqueous base

(ii) a cationic fabric softener material;

(iii) a fatty acid material; and

(iv) ethylene glycol distearate.

3. A composition according to claim 1 or 2 wherein the ethylene glycol distearate is present as a separate dispersed phase.

4. A method of preparing an aqueous liquid fabric conditioning composition according to one or more of the preceeding claims, which method comprises the steps of:

(i) forming a first dispersion in water, wherein the dispersed phase comprises the cationic softening material; and

(ii) adding a pre-dispersion of ethylene glycol distearate to this first dispersed phase.

5. Method according to claim 4 comprising the steps of

(i) forming the first dispersion in water at an elevated temperature;

(ii) cooling the first dispersion to ambient temperature; and

(iii) adding the pre-dispersion of ethylene glycol distearate at ambient temperature.