EP0885278B1

EP0885278B1 - Fabric softening composition

Info

Publication number: EP0885278B1
Application number: EP97904366A
Authority: EP
Inventors: Ailsa Pauline Hilary Grieveson; Christopher Whaley
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 1996-02-09
Filing date: 1997-01-28
Publication date: 2001-08-29
Anticipated expiration: 2017-01-28
Also published as: DE69706405D1; AR005743A1; DE69706405T2; EP0885278A1; AU1720797A; BR9707273A; WO1997029171A1; JP2000504754A; CA2246060C; ES2163121T3; CA2246060A1; GB9602619D0

Description

This invention relates to fabric softening compositions containing a skin benefit agent such that when fabrics are treated with the fabric softening composition when in contact with the skin the fabrics deliver the skin benefit agent to the skin
Rinse added fabric softener compositions are well known. Typically such compositions contain a water insoluble amine salt and/or a quaternary ammonium fabric softening agent dispersed in water at a level of softening agent up to 7% by weight in which case the compositions are considered dilute, or at levels from 7% to 50% in which case the compositions are considered concentrates. Quaternary ammonium materials with long chain substituents have been used in fabric softening compositions for many years. Often they are used in conjunction with co-actives such as fatty acids or other relatively cheap materials which also provide softening benefits.
In addition to softening, fabric softening compositions desirably have other benefits.
GB 1 601 359 ( Procter and Gamble ) and GB 1 550 205 (Procter and Gamble) describes the use of ester oil and silicones as an ingredient in a fabric softening composition as fabric lubricants suggested which may give ease of ironing benefits, and softening.
EP 0 436 729 (Kanebo) discloses an industrial process for applying microcapsules to fabric, which when contacted with the skin are physiologically active.
Accordingly the present invention provides a fabric softening composition comprising a skin conditioning compound comprising a C₈-C₂₂ α-hydroxyacid, an ester of a α-hydroxyacid or mixtures thereof and a biodegradable, fabric softening quaternary ammonium compound as defined in claim 1.
In a second aspect of the present invention there is also provided the use of an α-hydroxyacid, or an ester thereof, in a fabric treatment composition such that skin is conditioned when fabrics treated with said composition come into contact with the skin.
It is preferred if the skin conditioning agent is an α-hydroxy carboxylic acid or ester or mixtures thereof. It is further preferred if the skin conditioning agent is represented by formula I: R¹- [0-CH(R³)-CO]_m-OR²
In which R¹ is H or a C₁₀-C₂₂ acyl group and R² is H, a C₁₀-C₂₂ alkyl group, or a compatible counterion, for example sodium, potassium, or quaternary ammonium, R³ is hydrogen or C₁-C₂₀ alkyl group and m is equal to 1 or 10 with the proviso that if R¹ and R² are both hydrogen R³ is C₆- C₂₀ alkyl group.
Preferred α-hydroxyacids and esters for use with the invention may be represented by formula II and include glycollic acid esters, alkyl lactates, acyl lactylates, citric acid esters, tartaric acid esters, α-hydroxycaprylic acid esters, and long chain α-hydroxyacids (greater than or equal to 8 carbon atoms), for example α-hydroxycaprylic acid. R¹-O-CH(CH₃)CO.OR²
In which R¹ is H or a C₁₀-C₂₂ acyl group and R² is H, a C₁₀-C₂₂ alkyl group, or a compatible counterion, for example sodium, potassium, or quaternary ammonium, with the proviso that R¹ and R² cannot both be H.
It is especially preferred if the α-hydroxyacid ester is an alkyl lactate or acyl lactylate.
The level of acyl lactylate or alkyl lactate is preferably 5 to 30 wt%, most preferably 10 to 25wt% of the total composition.
Compositions according to the invention contain a quaternary ammonium fabric softeners compound. Advantageously the fabric softening composition comprises a water insoluble cationic compound having two C_12-28 alkyl or alkenyl groups. It is especially preferred if these C_12-28 alkyl or alkenyl groups are connected to the N atom via one or more ester links.
One type of ester-linked quaternary ammonium material used in the compositions according to the invention is represented by the formula:
In which each R⁴ group is independently selected from C_1-4 alkyl, hydroxyalkyl groups or C_2-4 alkenyl groups; wherein each R⁵ group is independently selected from C_8-28 alkyl or alkenyl groups; X^- is a suitable counter ion and n is o or an integer from 1-5.
Materials of this class and their method of preparation are described in US 4 137 180 (Lever Brothers). Analysis of such materials shows that they also comprise small amounts of the corresponding dimethylamine salt, one such salt being N,N-dimethyl-2,3-bis[hardened tallowoyloxy]-propylamine hydrochloride. Advantageously these materials comprise small amounts of the corresponding monoester as described in US 4 137 180, for example, 1-hardened tallowoyloxy-2-hydroxy-3-trimethylammonium propane chloride.
A further type of cationic softener used in the composition according to the invention is represented by the formula:
wherein each R⁶ group is independently selected from C_1-4 alkyl, hydroxyalkyl or C_2-4alkenyl groups; and wherein each R⁷ group is independently selected from C_8-28 alkyl or alkenyl groups;
T is
and
n is o or an integer from 1-5 and X^- is any suitable anion.
A further advantage of using ester linked quaternary ammonium materials with the above formula is that when fabric softening compositions containing them have excellent viscosities and are stable on storage.
Preferably the level of ester linked quaternary ammonium compounds is at least 1% by weight of the composition, more preferably at least 3% by weight of the composition; especially interesting are concentrated compositions which comprise at least 7% of ester-linked quaternary ammonium compound. The level of ester-linked quaternary ammonium compounds preferably is from 1% to 80% by weight, more preferably from 4% to 32%, most preferably from 6% to 22%.
The ratio of fabric softening compound to acyl lactylate/alkyl lactate is preferably from 0.5:1 to 1:5, more preferably from 1:1 to 1:4.
The softening composition may also comprise a nonionic stabilising agent selected from:
i. linear C₈ to C₂₂ alcohol alkoxylated with 10 to 20 moles of alkylene oxide; and
ii. a C₁₀ to C₂₀ alcohol or mixtures thereof.
Advantageously the nonionic stabilising agent is a linear C₈ to C₂₂ alcohol alkoxylated with 10 to 20 moles of alkylene oxide. Preferably the nonionic stabiliser has an HLB value of from 10 to 20, more preferably from 12 to 20.
Preferably, the level of nonionic stabiliser is within the range from 0 to 10% by weight, more preferably from 0 to 5% by weight, most preferably from 0 to 4% by weight. When nonionic stabilising agent is present the mole ratio of the quaternary ammonium compound to the nonionic stabilising agent is within the range from 40:1 to 1:1, preferably within the range from 18:1 to 3:1.
Preferably the compositions of the invention are liquids comprising an aqueous base.
The composition can also contain a co-active for example a C₈ - C₂₄ alkyl or alkenyl monocarboxylic acid or polymer thereof. Preferably saturated fatty acids are used, in particular, hardened tallow (C₁₆-C₁₈₎ fatty acids. Preferably the fatty acid is non-saponified, for example free oleic acid, lauric acid or tallow fatty acid. Lanolin or other nonionic fabric softening agents may also be used as co-actives.
The level of co-active material is preferably more than 0.1% by weight, more preferably more than 0.2% by weight. Especially preferred are concentrates comprising from 0.5 to 20% by weight of co-active, more preferably 1% to 10% by weight. The weight ratio of quaternary ammonium/amine material to co-active material is preferably from 10:1 to 1:10.
The composition can also contain one or more optional ingredients, selected from non-aqueous solvents, pH buffering agents, perfumes, perfume carriers, fluorescers, colourants, hydrotropes, antifoaming agents, soil release agents, enzymes, optical brightening agents, opacifiers, anti-shrinking agents, anti-spotting agents, germicides, fungicides, anti-oxidants, anti-corrosion agents, and antistatic agents.
The invention will now be illustrated by the following nonlimiting examples. In the examples all percentages are expressed by weight.

Example 1

A fabric softening composition comprising:
4.29 wt% quaternary ammonium cationic¹
0.71 wt% fatty acid²
15.00 wt% lauryl lactate³
to 100 wt% water and minors

Example 2

A fabric softening composition comprising:
4.29 wt% quaternary ammonium cationic¹
0.71 wt% fatty acid²
10.00 wt% lauryl lactate³
to 100 wt% water and minors

Preparation of Examples

The fabric softening compositions of the Examples were prepared by heating admixtures of cationic/fatty acid to above 70°C in lauryl lactate and slowly adding the mixture to hot demineralised water with vigorous shear.
A comparative example containing 4.29% quaternary ammonium cationic and 0.71 wt% fatty acid was prepared in a similar manner.
The Comparative Example and Example 1 were used to treat terry towelling in 1L tergotometer pots (liquor:cloth = 40:1, ambient temperature, 5 mins., 65 rpm). The terry towelling was spun to remove excess liquor and then line dried. The treated terry towelling pieces were rubbed onto the front forearms of the panellist for one minute. Tape strips samples of the skin surface were taken and analysed for lactate content using a standard method involving Sigma 735-10 lactate reagent. The results are shown in the Table below and clearly illustrate the increased level of lactate found on using the formulation of Example 1.

Example Dosage (ml) Lactate (µg/cm²)

1 0.67 1.11

Comparative 2 0.43

1 1.33 0.95

Comparative 4 0.33

Claims

A fabric softening composition characterised in that it comprises:

i) a skin conditioning compound comprising a C₈-C₂₂ α-hydroxyacid, an ester of a α-hydroxyacid or mixtures thereof and;

ii) a biodegradable, fabric softening quaternary ammonium compound represented by the formula:
in which each R⁴ group is independently selected from C_1-4 alkyl, hydroxyalkyl groups or C_2-4 alkenyl groups; wherein each R⁵ group is independently selected from C_8-28 alkyl or alkenyl groups; X^- is a suitable counter ion and n is o or an integer from 1-5, or by the formula:
wherein each R⁶ group is independently selected from C_1-4 alkyl, hydroxyalkyl or C_2-4 alkenyl groups; and wherein each R⁷ group is independently selected from C_8-28 alkyl or alkenyl groups;
T is
and n and X^- are as defined above.
A fabric softening composition according to claim 1 in which the skin conditioning agent is represented by the formula: R¹-[0-CH(R³)-CO]_m-OR² in which R¹ is H or a C₁₀-C₂₂ acyl group and R² is H, a C₁₀-C₂₂ alkyl group, or a compatible counterion, for example sodium, potassium, or quaternary ammonium, R³ is hydrogen or C₁-C₂₀ alkyl group and m is equal to 1 or 10 with the proviso that if R¹ and R² are both hydrogen R³ is C₆- C₂₀. alkyl group.
A fabric softening composition according to any preceding claim in which the skin conditioning compound is an acyl lactylate or an alkyl lactate or mixtures thereof.
A fabric softening composition according to any preceding claim in which the alkyl lactate or acyl lactylate has the following formula: R¹-O-CH(CH₃)CO.OR² in which R¹ is H or a C₁₀-C₂₂ acyl group and R² is H, a C₁₀-C₂₂ alkyl group, or a compatible counterion, for example sodium, potassium, or quaternary ammonium, with the proviso that R¹ and R² cannot both be H.
A fabric softening composition according to any preceding claim in which the level of skin conditioning compound is from 5 to 30 wt%.
A fabric softening composition according to any preceding claim in which the ratio of fabric softening compound to skin conditioning compound is in the range from 1:1 to 1:5.
Use of an α-hydroxyacid or esters thereof in a fabric softening composition as defined in any proceeding claim such that skin is conditioned when fabrics treated with the composition come into contact with the skin.
Use of an α-hydroxyacid ester in a fabric softening composition according to claim 7 in which the α-hydroxyacid ester is an alkyl lactate or an acyl lactylate.