AU666135B2

AU666135B2 - Fabric softener composition

Info

Publication number: AU666135B2
Application number: AU27267/92A
Authority: AU
Inventors: Paul Lawrence Heffernan; Inderbir Tranter
Original assignee: Cussons International Ltd
Current assignee: Cussons International Ltd
Priority date: 1991-10-23
Filing date: 1992-10-22
Publication date: 1996-02-01
Anticipated expiration: 2012-10-22
Also published as: AU2726792A; GB9122486D0; GB9222200D0; GB2260771A

Description

Our Ref: 447308 AM&13 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT e s s r Applicant(s): Cussons (International) Limited Bridgewater House Whitworth Street MANCHESTER M1 6LU UNITED KINGDOM DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Fabric softener composition Address for Service: Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 1 FABRIC SOFTENER COMPOSITION This invention relates to a fabric softener composition.

It is well known to use fabric softener compositions in the laundering of textile material in order to improve the handle of the washed material.

Conventional fabric softener compositions are usually based upon tallow substituted quaternary ammonium compounds or imidazoline compounds as active ingredient.

The preparation of these compositions requires very careful and gradual addition of the active ingredient to water that is maintained at an elevated temperature of the order of 55 0 C. In other words the conventional mthod of preparation is relatively slow and also requires heat energy. However, 'in addition to those disadvantages it is difficult to obtain a high concentration of active ingredient. This is a particularly serious drawback to conventional fabric softener compositions. High concentration fabric softener compositions can be packaged in smaller containers than the more dilute compositions. Not only does this save considerably on the packaging costs, but it also reduces the cost of transport and as well reduces the shelf space required for storage and for display at the point of sale. For the purchaser there is a le s bulky container that needs to be carried home.

-2- A considerable effort has, therefore, been made to produce fabric softener compositions with a higher concentration of active ingredient. While there has been some success in that field the concentrated compositions are generally very watery if they are diluted by the user. This watery physical appearance of the diluted composition is perceived by the user as an indication that the composition is not very-effective. The received wisdom of the users of fabric softeners is that the effectiveness of a softener composition is related to its viscosity in that the less viscous the composition the less effective it will be. Although this is not necessarily true it represents a severe marketing difficulty. The normal recommendation for use of concentrated fabric softeners is, therefore, not to dilute them, but just to use a smaller dose than would be used with a regular strength product.

The present invention has been made with a view to dealing with these problems.

S S According to the invention there is provided a method of increasing the viscosity of a fabric softener composition comprising diluting with water a concentrated fabric softener composition, said concentrated composition comprising at least 35 by weight of active ingredient, said active ingredient comprising a quaternary ammonium compound, the dilution being in the range 1:1 to 1:20 concentrated fabric softener composition to diluent.

The quaternary ammonium compounds for use in the present invention include conventional compounds such as V C Wq J 3 di-alkyl di-methyl ammonium chloride, imidazoline quaternary ammonium compounds and diamido alkoxylated quaternary ammonium compounds.

In a preferred embodiment of the concentrate the active ingredient is present in an amount not less than by weight. Preferred active ingredients include alkyl or alkenyl substituted imidazoline quaternary ammonium compounds.

The concentrate preferably also includes a water miscible solvent for the active ingredient. Preferred :iiii :solvents include alcohols particularly glycols.

The concentrate can be made by combining the :.....constituents in any order and without heating. They are, therefore, vei much easier and cheaper to produce than the known compositions.

S. *S• The invention also provides a fabric softener cor-nosition comprising a concentrate diluted with water, C. concentrate being as defined above. The dilution is in the range from 1:1 to 1:20 parts by volume of concentrate to diluent and preferably in the range 1:5 to 1:15.

The concentrates may also include addihives such as r/ dye, perfume, preservatives and the like.

4 The fabric softener concentrates are relatively low viscosity liquids which are transparent at ambient temperatures. Surprisingly when diluted with water prior to use the viscosity increases substantially.

This totally unexpected consequence of dilution means that the perceived disadvantage of the watery appearance of diluted prior art concentrates is disposed of.

The rise in viscosity from concentrate to diluted 0000 product may be explained by the structuring of the :0 liquid on transition from a predominantly organic 0 solvent based system to an aqueous system.

in the former case the cationic active is in true solution whereas in the latter case it is in the form of 0.00 dispersed multi-layered vesicles. These structures can clearly be seen using a microscope on high magnification (of the order of x 1000) In the case of oleic acid based imidazoline quaternary amnmoniumn compounds which are liquid at room temperature at 75% active they even form when the raw material is mixed with cold water with vigorous shaking by hand. Previous fabric softener formulations have necessitated carelful temperature control and carefully controlled mixing conditions in order to obtain the desired liquid structure with a satiatactory particle size distribution.

The careful control of these manufacturing variables is unnecessary with the invention because the strzucturing takes place on dilution of the product by the consumer. Simple mixing and shaking with cold water is all that is needed.

The product being isotropic is transparent or almost transparent. If that is not wanted a pearlising agent may be incluided which renders the product non-transparent and gives it a pearly sheen.

It would seem that that particle size affects viscosity and stability, If there are a significant proportion of particles greater than around 20 microns 94. 9in diameter then this can give rise to instability (viscosity rise and even gelling) For good stability, the distribution needs to be fairly narrow and preferably the median needs to be under 10 microns. it also seems to be the case that if particles are too large (ie >20iWm) they do not soften as well as smaller ones. However, we have found that the particle size distribution of the diluted product of the invention is similar to that of regular strength prior art compositions and that no particle size related problems arise.

"The following Example further illustrates the 6

EXAMPLE

A concentrated fabric softener was formulated as follows: _by weight Water 15.00 Hexylene glycol 15.00 Rewoquat t W3690 67.'00 Perfume 3.00 "Rewoquat" is a commercially available oleic acid derived imidazoline quat )rnary ammnonium compound, active in isopropyl alcohol (IPA) or dipropylene glycol

(DPG).

The concentrate was produced by dispersi4ng dye in *0*the water, adding the haxylene glycol with stirring and subsequently the kRewoquat" also with stirring. No :heat was applied. Stirring was continued until the mixture was clear whereupon the perfume was added.

The viscosity of the product (Brookfield RVT Spindle 3, 50 rpm at 25*C) was 60-70 cp when the "Rewoquat" used was in IPA and 120 op when the "Rewoquat" was DPG based.

*4or use 1 part of the concentrate was diluted with 9 parts of water. The viscosity was from 200 to 300 cp.

-7 Both concentrate and diluted product were found to be stable at room temperature and at 370 for four months.

The softening performance of the diluted product Was evaluated using the following protocol: A number of loads of washing consisting of two cotton hand towels together with other fabric items such as polyester/cotton blend sheets and pyjamas, woollen/nylon jumpers and nylon underwear were assembled. Each load weighed about 2.5 Kg. The loads .*were washed in front loading automatic washing machines using a standard detergent powder. Diluted fabric softener of the invention was added to one or more loads, prior art fabric softener composition added to e 9* other-loads and some loads were washed without fabric Ssoftener. The towels were air dried on a washing line.

ego• 6 SThe towels were evaluated for softness by a panel of judges who applied a rating based on a scale of from 1 (very harsh) to 10 (very soft).

The results were as follows:- 8- Regular Strength prior art Diluted Control Composition Product 3.88 7.33 7.58 Significance level (0.i% There was statistically no significant difference to.I.

to: in the softening performance of regular strength prior art composition and diluted product of the invention at equal dosage (90g) With this protocol a score above 7 represents a premium quality fabric softener.

66*6 The invention is not restricted to the a* above-described embodiment and many variations and S Smodifications can be made.

Claims

9- The claims defining the invention are as follows: 1. A method of increasing the viscosity of a fabric softener composition comprising diluting with water a concentrated fabric softener composition, said concentrated composition comprising at least 35% by weight of active ingredient, said active ingredient comprising a quaternary ammonium compound, the dilution being in the range 1:1 to 1:20 concentrated fabric softener composition to diluent. 2. A method as claimed in Claim 1 wherein the active ingredient is present in an amount of at least 0. 40% by weight. *e 3. A method as claimed in any preceding claim, wherein the active ingredient comprises di-alkyl di- methyl ammonium chloride, diamido alkoxylated .quaternary ammonium compounds, imidazoline quaternary ammonium compounds or mixtures thereof. 4. A method as claimed in Claim 3, wherein the active ingredient comprises an alkyl or alkenyl substituted imidazoline quaternary ammonium compound. A method as claimed in any preceding claim, wherein the composition further comprises a water miscible solvent for the active ingredient. kiV" 10 6. A method as claimed in Claim 5, wherein the solvent is an alcohol. 7. A method as claimed in Claim 6, wherein the solvent is a glycol. 8. A method as claimed in any preceding claim, wherein the ingredients are combined together in any order and without the application of heat. Se9. A fabric softener composition produced by the method as claimed in any preceding claim. 10, A fabric softener composition as claimed in Claim 9, wherein the dilution is in the range 1:5 to 1:15 parts by volume of concentrated fabric softener composition to diluent.
11. A method of manufacturing a concentrated fabric softener composition which comprises the steps of mixing without heating a quaternary ammonium compound which 0**e*o comprises at least 35% by weight of the total composition, with an alcohol and water and optionally also a perfume, such that the composition is capable of dilution with water before use within a weight ratio range of concentrate to water from 1:1 to 1:20, said dilution resulting in an increase in viscosity.
12. A method of increasing the viscosity of a fabric softener and the fabric softener composition produced by this method, substantially as hereinbefore defined with reference to the Example. S DATED this 16th day of November, 1995. S t I CUSSONS (INTERNATIONAL) LIMITED 'r o By Its Patent Attorneys DAVIES COLLISON CAVE IABSTRACT FABRIC SOFTENER COMPOSITION A conicentrated fabric softener composition which includes at least 35% of a quaternary ammonium compound in a water miscible solvent. on addition of the concentrate with water for use, the viscosity of the composition increases. *too co-op go 0