EP0720645B1

EP0720645B1 - Rinse conditioner

Info

Publication number: EP0720645B1
Application number: EP94926226A
Authority: EP
Inventors: Sigrun Eriksen
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 1993-09-22
Filing date: 1994-08-30
Publication date: 1998-12-23
Anticipated expiration: 2014-08-30
Also published as: GB9319566D0; EP0720645A1; BR9407645A; DE69415546T2; JPH09503009A; WO1995008618A1; ES2124909T3; AU7614794A; DE69415546D1

Description

This invention relates to Rinse Conditioners comprising a softening or anti-static component.

In the past fabric conditioning has been carried out either during the rinsing step of a fabric washing and rinsing process or during tumble drying of the fabric. In almost all cases rinse conditioning is accomplished by adding a liquid dispersion of a rinse conditioning agent to the rinse liquor. The liquid dispersion was traditionally distributed and made available to consumers as a ready to use aqueous dispersion. More recently, concern for the environment and consumer convenience has led to the sale of concentrated aqueous dispersions which are either used in smaller amounts or are mixed with water to form a predilute before use.

In EP 234082 it has been proposed to supply rinse conditioner as a solid block. This approach requires the use of a special restraint for the block and may also require the modification of the washing machine to enable the block to be dissolved and dispensed by a spray system.

Various proposals have been made to supply fabric softener in granular or powdered form. EP 111074 is typical and uses a silica to carry the softener. A disadvantage of using a carrier such as silica is that it bulks up the product and serves no function beyond making the powder compatible with other ingredients that may be contained in a washing powder.

WO 92/18593 describes a granular fabric softening composition comprising a nonionic fabric softener and a single long alkyl chain cationic material. The specification teaches that effective cationic softening compounds when used in granular form exhibit poor dispersion properties.

It is well known to the person skilled in the art that poor dispersion of a fabric softening active can lead to poor softening of fabrics and unsightly deposition of clumps of fabric softening actives on the fabric.

The problem of poor dispersion of granular compositions is overcome by EP 569 184. This application discloses use of the granular composition to form a pre-dilute which is then added to the dispenser drawer of the washing machine.

EP 568 297 discloses a granular fabric conditioner comprising a nonionic dispersing aid and a water insoluble cationic active having the formula:

wherein each R₁ group is independently selected from C_1-4 alkyl, hydroxyalkyl or C₂-C₄ alkenyl groups; and wherein each R₂ group is independently selected from C_2-27 alkyl or alkenyl groups and n is an integer from 0-5.

A further problem with some cationic fabric conditioning actives is that of hydrolytic stability. EP 0 239 910 (Procter and Gamble) discloses this problem and attempts to solve it by limiting the pH range of aqueous formulations.

The present invention mitigates the problems of both hydrolytic stability and of dispersion of a granular fabric conditioner.

According to the present invention there is provided a powdered rinse conditioner comprising:

a) at least 40% by weight of a water insoluble cationic active having the formula:

in which R¹ is a C₁-C₄ alkyl groups, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups, X^- is a softener compatible anion and T is

and;

b) a wetting aid.

c) 1 wt% to 20 wt% of a fatty acid.

It is preferred if the water insoluble cationic active has the formula:

in which R¹ is a C₁-C₄ alkyl groups, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups, X^- is a softener compatible anion.

It is further preferred if the water insoluble cationic active is N,N-di(tallowoyl-oxy-ethyl) N,N-dimethyl ammonium chloride.

It is advantageous for good dissolution and dispersion if the temperature of the rinse water is above 10°C, preferably above 20°C. However an acceptable level of softening is achieved below 10°C.

Preferably the cationic active comprises more than 40% by weight of the powder and less than 95% by weight of the powder, more preferably the level of cationic active is greater than 60% by weight of the powder.

The powder may also contain a co-active at levels of up to 20%. Preferred co-active are fatty acids.

It is preferred if from about 1 wt% to about 15 wt% of fatty acid is present in the composition to boost softening. Ideally the ratio of cationic active:fatty acid is greater than 6:1. More preferably the ratio of cationic active:fatty acid is 12:1, most preferably 20:1. The fatty acid co-active may comprise hardened tallow fatty acid.

The composition of the invention also contains a wetting aid. In the context of the present invention a wetting aid may be defined as any material which promotes the ingress of water into the softening material thus aiding dispensing and dispersion of the material. In some instances the wetting aid may further boost softening. Preferred wetting aids are nonionic materials such as sugar alcohols, alcohol ethoxylates, (poly)ethylene glycols and mixtures thereof. Of particular use with the present inventions are long chain alcohol ethoxylates preferably alcohol ethoxylates with a chain length between 9-20, most preferred due to superior biodegradability are alcohol ethoxylates with greater than 5 moles of ethylene oxide such as Dobanol 91-6EO (trademark ex Shell) and Genapol C100 (trademark ex Hoechst).

Preferably the level of wetting aid is between 1 wt% and 20 wt%.

Advantageously the powder may also contain a flow aid and other ingredients commonly found in rinse conditioners such as perfume, antifoam, preservative, dye and dispersing aids such as low molecular weight cationics.

It is advantageous for environmental reasons if the quaternary ammonium material is biologically degradable.

The invention is of particular use when applied directly to the rinse liquor.

The invention will now be described with reference to the following non-limiting examples:

EXAMPLES

Examples were prepared according to the formulation in Table 1. These examples are no longer illustrative of the invention.

	Weight %
Composition	Example 1	Example A	Example B
DEEDMAC	89	-	-
Stepantex	-	89	-
Arquad 2HT	-	-	89
Perfume	3.8	3.8	3.8
Microsil	4	4	4
Genapol C100	3.2	3.2	3.2

The dispersibility of the Examples in water was evaluated by weighing 5g of conditioner powder into a glass jar and adding 95g of demineralised water (at 20°C or 7°C). The jar was sealed and shaken for 2 seconds. The dispersion was filtered through pre-weighed polymon 43T (trademark) (150 µm) mesh. The mesh was then oven dried and the percentage residue calculated.

The dispersibility results are illustrated in Table 2.

Example	Residue at 20°C	Residue at 7°C
1	2.5	14
A	21	14
B	21	18

The results show the Example 1 has superior dispersibility to examples A & B when the water temperature is 20°C.

The softening properties on fabric of Examples A, B and 1 were evaluated by adding three 19 x 19 cm sqare of standard 8 terry towelling (40g) to cold US water. 1ml of sodium alkyl benzene sulphonate solution was added and the cloths stirred (80 rpm) for one minute. The cloth was removed from the pot and at the relevant time the product was added to the added to the solution. The cloths were added to the pot and stirred for 5 minutes. The cloths were removed, spun dry and line dried overnight.

Softening of the fabrics was assessed by an expert panel of 4 people using a round robin paired comparison test protocol. Each panel member assessed four sets of test cloths. Each set of test cloths contained one cloth of each test system under evaluation. Panel members were asked to pick the softer cloth of each pair during evaluation. A "no difference" vote was not permitted. Softness scores were calculated using an "Analysis of Variance" technique. Higher values are indicative of better softening.

The softening scores of Examples A, B and 1 are illustrated below.

Example	Softening Score (7°C)
1	88
A	42
B	42

It is thus demonstrated that Example 1 softens better than Example A and B.

Claims

A powdered rinse conditioner comprising:

a) at least 40 wt % of water insoluble cationic active having the formula:
in which R¹ is a C₁-C₄ alkyl group, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups, X^- is a softener-compatible anion and T is

b) a wetting aid.

c) 1 wt% to 20% wt of a fatty acid.
A powdered rinse conditioner according to claim 1 in which the water insoluble cationic active has the formula:
in which R¹ is a C₁-C₄ alkyl groups, R² and R³ are the same or different C₁₂ - C₂₂ alkyl or alkenyl groups and X^- is a softener-compatible anion.
A powdered rinse conditioner according to claim 2 in which the water insoluble cationic active is N,N-di(tallowoyl-oxy-ethyl) N,N-dimethyl ammonium chloride.
A powdered rinse conditioner according to any preceding claim in which the wetting aid is a nonionic active.
A powdered rinse conditioner according to any preceding claim in which the level of wetting aid is between 1 wt% and 20 wt%.
A powdered rinse conditioner according to any preceding claim which comprises between 1 wt% and 15 wt% fatty acid.