CA2168346A1

CA2168346A1 - Pearlescent based concentrate for personal care products

Info

Publication number: CA2168346A1
Application number: CA002168346A
Authority: CA
Inventors: Katherine Margaret Wansborough; Anne Maree Lombard; Pamela Joyce Jones
Original assignee: Individual
Current assignee: Orica Australia Pty Ltd
Priority date: 1993-07-28
Filing date: 1994-07-26
Publication date: 1995-02-09
Also published as: KR960703565A; WO1995003782A1; NZ269755A

Abstract

A pearlescent based and method of preparation wherein the comprises at least one alkylpolysaccharide, traditional pearlscent ester or acid and alkyl sulphates. The concentrate is suitable for use in personal care products of low irritancy to the skin of users.

Description

2 216 g ~ ~ 6 PCT/AU94/00421 PEARLESCENT BASED COrl~ ATE
FOR PERSONAL CARE PRODUCTS
The invention relates to pearlescent based concentrates comprising at least one alkylpolysaccharide, traditional pearlescent esters or acid and alkyl sulphates and to processes for the preparation thereof.

Personal care products such as handsoaps, bubble baths, shampoos and hair conditioners often include in their composition agents which impart a pleasant, pearl-like glossy appearance in order to enhance the appeal of such products to the consumer. The agents which impart this appearance are known as pearlescent based concentrates and generally comprise microscopic platelike crystals which remain dispersed in compositions to which they are added and reflect light in such a manner as to impart a pearl-like appearance.

Pearlescent based concentrates of the prior art have included finely divided natural substances or inorganic compounds such as mica, fish scale, bismuth oxychloride or the like. For example, Japanese patent application no.
90/134,825 tPriority Date; 24 May 1990) describes compositions for cosmetics having a pearly appearance, comprising glucose fatty acid esters and mica and/or mica Ti.

In recent years, the use of a fatty acid glycolic ester in pearlescent concentrates has been particularly favoured.
In general such concentrates are produced by adding a fatty acid glycolic ester which is solid at room temperature to a composition such as shampoo or the like, followed by heating of the mixture to melt the fatty acid glycolic ester, and then by cooling to recrystallise it and thereby providing small crystals which impart a pearl-like gloss to the composition. In an alternative method of production, a pearling agent dispersion (such as a fatty acid glycolic ester dispersion, which is dissolved and cooled to recrystallise in advance) is mixed with a shampoo or the like at room temperature as described in Japanese Patent Application nos. 71021/81 and 216728/83.

21683~ 2 Other known pearlescent based concentrates have comprised microcrystalline polyvalent metal salts of higher fatty acids or fatty acid glycolic esters such as those described in United States Patent 4,959,200 (Date of Patent; 25 September 1990).

Other commonly used pearlescent based concentrates have been prepared using ethylene glycol monostearate, ethylene glycol di-stearate, glycerol monostearate, glycerol di-stearate or a cetyl stearly alcohol or the like in conjunction with other similar esters. These pearlescent based concentrates of the prior art have also normally comprised ether sulphates, betaines, ethanolamide, amine based surfactants and the like which can be used as emulsifiers. United States Patent 5,017,305 (Date of Patent;
21 May 1991) describes a typical pearlescent concentrate in the form of a free-flowing dispersion comprising pearlescing esters, ether carboxylic acids and one or more monoethanolamides of Cl2 to C22 fatty acids-One of the disadvantages of the pearlescent based concentrates of the prior art is that they often comprisechemicals which are potential skin sensitisers. Japanese Patent Application no. 21678/83 for example, discloses a pearling agent containing a salt of alkyl sulphate or a salt of polyoxyalkylene alkyl sulphate, a fatty acid dialkanolamide and water as solvents, and a fatty acid glycolic ester at a high concentration. Many factors influence the irritation effect of surfactants and the molecular structure of the surface active agent can be closely linked to its effect on adsorption, solubilization, penetration, swelling, denaturation and general irritation on human skin.

Generally, the order of increasing human skin irritation of anionic surfactants commonly used in personal care products is in the following order:
Ammonium Laureth Sulphate <Sodium Laureth Sulphate <Ammonium Lauryl Sulphate <Sodium Lauryl Sulphate.

WOgS/03782 21~ ~ 3 ~ 6 PCT/AU94/0042l Furthermore, some of the pearlescent based concentrates of the prior art have included surfactants which may contain toxic trace impurities which are suspected carcinogens including nitrosamine containing compounds such as diethanolamides. European Patent no. 221465 (22 October 1992) for example, relates to a process for the production of pearlescent pigment comprising ethanolamide.

In general, alkyl polyglucosides demonstrate very little tendency to scalp irritations.

It has now been found that low irritant pearlescent based concentrates containing biodegradable surfactants can be prepared using alkylpolysaccharides. Ultimate biodegradability was measured using OECD tests 301E and 301A,1981. Alkylpolysaccharides are particularly attractive for use in personal care products because they contain no toxic trace impurities and because they are derived from renewable resources such as coconut oil and wheat starch.

The current invention therefore provides a pearlescent based concentrate including:
between 5 and 40% by weight of the composition of alkylpolysaccharide of formula where Rl is selected from the group comprising linear or branched C6 to C22 alkyl or alkenyl group where G is selected from the group comprising a Cs or C6 saccharide and x is from 1 to 10;

between 3 and 30% by weight of the composition of alkyl sulphate and/or alkyl ether sulphate;
and between 5 and 20% by weight of pearlescing esters of formula R -(ocnH2n)x OR
where R is chosen from the group including C}6 to C22 fatty acyl groups, R3 is chosen from the group comprising H or R , 21683~ 4 n is 2 or 3 and x is from l to 120.

The current invention further provides a pearlescent based concentrate including:
S H-G~-OR
where Rl is selected from the group comprising linear or branched C6 to C22 alkyl or alkenyl group where G is selected from the group comprising a C5 or C6 saccharide and x is from l to l0;
between 3 and 30% by weight of the composition of alkyl sulphate and/or alkyl ether sulphate;
and between S to 20% by weight of pearlescing acid of formula R COOH
where R is chosen from the group comprising Cl6 to C22 alkyl groups.

In a preferred embodiment the pearlescing esters or acid of the current invention is chosen from ethylene glycol monostearate, ethylene glycol disterate, stearic acid and mixtures thereof.

In a preferred embodiment the pearlescent based concentrate of the current invention further includes secondary alkane sulphonates of the formula R - CH(CH3)S03M
where R4 is chosen from the group comprising C6 to C22 alkyl groups and M is chosen from the group comprising alkali metals In a further preferred embodiment the fatty alcohol ethoxylates used in pearlescent based concentrate of the current invention are of the formula R (OC2H4)y OH
where Rs is chosen from the group including C6 and C22 alkyl or alkenyl groups and y is from l to 120 WOgS/03782 216 ~ 3 A ~ PCT/AU94/00421 s The pearlescent based concentrate of the current invention may further include between 0 and 30% by weight of the composition of one or more optional additives chosen from the group including:
alkylsulphosuccinate or polyoxyalkylenealkylsulphosuccinate of the formula R ~O~ [ CH ( R ) CH20 ] n~ [ COCH ( SO3M) CH2COOM ]
where R6 is chosen from the group including C8 to C20 linear or branched alkyl groups, R is H or CH3 ~
Ml and M are independently chosen from the group comprising alkali metals, alkaline earth metals, NH4+, C1 to C3 alkyl groups, substituted ammonia and hydroxy substituted C2 or C3 alkyl substituted ammonia and n is from 0 to 8;
sorbitan fatty acid esters of formula, CH2- ( CHOH ) 3-CHOCH20R
where R is chosen from the group including C12 to C18;
secondary alkane sulphonates; fatty alcohol alkoxylates;
fatty acid alkoxylates; fatty alcohols; alkanoyl N-methylglucamides; ether carboxylic acids; ethoxylated sorbitan fatty acid esters; and alpha-olefin sulphonates.

In a preferred embodiment the optional additives of the pearlescent concentrate of the current invention includes fatty alcohols of the formula R OH
where R9 is chosen from the group comprising C6 to C22 alkyl groups In a further preferred embodiment the optional additives of the pearlescent concentrate of the current invention includes alkanoyl N-methylglucamides of the formula coRlo CH3-N-CH2(CHOH)4CH2OH
where R10 is chosen from the group comprising C6 and C22 alkyl groups.

WOg5/03782 PCT/AU94/00421 21683i6 6 In another preferred embodiment the optional additives of the pearlescent concentrate of the current invention includes ether carboxylic acids of the formula RllC(O)O(C2H40)mH
where R11 is chosen from the group includes C6 to C22 alkyl groups and m is from l to 120 In a further preferred embodiment the optional additives of the pearlescent concentrate of the current invention comprise ethoxylated sorbitan fatty acid esters of the formula ( OCH2CH2 ) WOH

( OCH2CH2 ) VOH
CH2 ( CH2CH2 ) uH
CH2(OCH2CH) tOC ( O ) Rl where Rl2 is chosen from the group comprising C6 to C22 alkyl groups and w, v, u, t are from 4 to 20 In a further preferred embodiment the optional additives of the pearlescent concentrate of the current invention comprise alpha-olefin sulphonates of formula R CH = CHCH2SO3M
where Rl3 is chosen from the group comprising C6 to C22 alkyl groups and M is chosen from the group comprising Na & K.

Another optional additive to the pearlescent based concentrates of the current invention is between 0 and 2% of at least one inorganic salt including alkali metal halide salt such as NaCl, KCl, Kl and the like.

The pearlescent based concentrates of the current invention may also be diluted with between lO and 90% of the weight of the composition of water or other suitable solvent.

W095/03782 216 8 ~ ~ ~ PCT/AU94/00421 The pearlescent based concentrates of the current invention may also have added optional agents including perfumes, pigments, W absorbers and antioxidants.

There is further provided a method of preparation of the pearlescent based concentrates of the current invention comprising the steps of;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present and stirrinq to form a homogeneous solution, and (b) cooling the stirring solution to a temperature of between 35C and 45C at a maximum cooling rate of 15C/hour.

The pearlescent based concentrates of the current lS invention may also be prepared by a method comprising the following steps;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present while stirrinq vigorously to form a homogeneous solution, (b) rapidly cooling the stirring solution to between 60C and 70 C, and (c) cooling the stirring solution to a temperature of between 35C and 45C at a maximum cooling rate of 15C/hour.

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

WOgS/03782 PCT/AU94/00421 A pearlescent based concentrate of the following composition was prepared by the method described below.

Com~onent ~ ComDosition (% w/w) Decylpolysaccharide (50% a.i.) 36.00 Sodium lauryl sulphate (30% a.i.)10.00 Ethylene Glycol mono-stearate 16.25 Sodium chloride 1.00 Water 36.75 Method Ethylene glycol monostearate, decylpolysaccharide, alkyl sulphate, water and sodium chloride were heated to 80C with vigorous stirring. The solution was maintained at 80C with stirring for further 30 minutes before being rapidly cooled to 65C. Once the solution temperature reached 65 C
the stirring rate was slowed and the solution cooled at a controlled rate of 10C per hour until the temperature reached 40C. The stirrer was then stopped and the pearlescent blend allowed to cool to room temperature.

A pearlescent based concentrate of the following composition was prepared by the method described below.

Component Composition (% w/w) Dodecylpolysaccharide (50% a.i.)25.00 Sodium lauryl sulphate (30% a.i.)31.00 TERIC 12A23 3.00 Ethylene glycol mono-stearate 12.50 Sodium chloride 1.00 ~ater 27.50 Method Ethylene glycol mono-stearate, dodecylpolysaccharide, sodium lauryl sulphate, TERIC 12A23 water and sodium chloride were heated to 80C with vigorous stirring. Once the solution had reached 80C, the stirring rate was slowed and the solution cooled at a controlled rate of 10C per hour until the solution temperature had dropped to 40C. When the solution temperature had reached 40C the stirrer was stopped 21 6 8 3 ~ ~ PCT/AU94/00421 Wo g5/03782 and the pearlescent based composition was allowed to cool to room temperature. (TERIC is a registered trade mark of ICI
Australia Operations Proprietary Limited).

5 Com~onent Composition (%w/w) Decylpolysaccharide (50% a.i.) 37.00 Sodium lauryl sulphate 10.00 Cetyl Stearyl alcohol 5.00 Ethylene glycol monostearate 16.25 Nater 32.75 Method Ethylene glycol monostearate, decylpolysaccharide, sodium lauryl sulphate, cetyl-stearyl alcohol and water were heated to 75C with vigorous stirring. The solution was cooled until the temperature reached 70C at which point the rate of cooling was controlled at 15C/hour and the stirring rate reduced. When temperature reached 40C, stirring was stopped and the pearlescent based composition allowed to cool to room temperature.

EXAMPL~ 4 ComPonent Composition (%w/w) Dodecylpolysaccharide (50% a.i.) 36.00 Ammonium lauryl sulphate (25% a.i.)10.00 Disodium alkyl ethoxy sulphosuccinate (30% a.i.) 13.3 Sodium chloride 1.0 Ethylene glycol distearate 16.25 Water 23.45 Method Dodecylpolysaccharide, ammonium lauryl sulphate, disodium alkylethoxy sulphosuccinate and ethylene glycoldistearate were blended together to form a homogeneous mixture. Sodium chloride was then dissolved in the water and added to the mixture which was heated to 70C with vigorous stirring. When the solution temperature reached 70C the stirring rate was reduced and the solution cooled at a rate of 8C/hr. When the solution temperature reached 40C the WO95/03782 ' PCT/AU94/00421 21683~16 lo stirring was stopped and the resultant pearlescent based concentrate left to cool to room temperature.

ComPonent Composition (%w/w) 5 Decyl Polysaccharide 25.00 Sodium lauryl sulphate 20.00 Ethylene glycol monostearate 7.50 Sodium Chloride 1.00 Water 46.5 Method The sodium chloride was dissolved in a portion of the water. The remaining components were blended together and the salt solution mixed in. The resultant mixture was heated to 70C with rapid stirring then the stirring rate was reduced and the mixture cooled at a rate of 8C per hour.
When the mixture reached 40C all stirring was ceased.

Component Composition (%w/w) Decyl Polysaccharide 25.00 20 Sodium lauryl sulphate 20.00 Sorbitan monolaurate 5.00 Ethylene glycol monostearate 15.00 Sodium Chloride 1.00 Water 34.00 Method The above components were combined according to the method of Example 5 to form a pearlescent based concentrate.

~XAMPL~ 7 ComPonent ComPosition (%w/w) C8-10 Polysaccharide 5.00 Decyl Polysaccharide 25.00 Sodium lauryl sulphate 20.00 Ethylene glycol monostearate 15.00 Sodium Chloride 1.00 Water 34.00 2 1 6 8 ~ ~ ~ PCT/AU94/004t1 W095t03782 Method The above components were combined according to the method of Example 5 to form a pearlescent based concentrate.

5 ComPonent Composition (%w/w) Decyl Polysaccharide 30.00 Ammonium lauryl sulphate 20.00 Ethoxylated sorbitan monooleate 2.50 Sodium Chloride 1.00 10 Ethylene glycol monostearate 15.00 Water 31.50 Method The above components were combined according to the method of Example 5 to form a pearlescent based concentrate.

Component Composition (%w/w) Decyl Polysaccharide 30.00 Sodium lauryl sulphate 15.00 Stearic acid 15.00 20 Sodium Chloride 1.00 Water 39.00 Method The above components were combined according to the method of Example 5 to form a pearlescent based concentrate.

ComPonent Composition (%w/w) C16-18 Polysaccharide 10.00 Decyl Polysaccharide 15.00 Sodium lauryl sulphate 15.00 30 Ethylene glycol monostearate 15.00 Sodium Chloride 1.00 Water 44.00 - Method The above components were combined according to the method of Example 5 to form a pearlescent based concentrate.

21683 1~ 12 The pearlescent based concentrates of each example exhibited small crystals of relatively uniform size which give a lustrous appearance to the concentrate and good reflectance.

While the invention had been explained in relation to its preferred embodiments it is~to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

The claims defining the inventions are as follows:

1. A pearlescent based concentrate comprising:
between 5 and 40% by weight of the composition of alkylpolysaccharide of formula H-Gx-OR1 where R1 is selected from the group comprising linear or branched C6 to C22 alkyl or alkenyl group where G is selected from the group comprising a C5 or C6 saccharide and x is from 1 to 10;

between 3 and 30% by weight of the composition of alkyl sulphate and/or alkyl ether sulphate;

and between 5 and 20% by weight of pearlescing compound of formula R2-(OCnH2n)x-OR3 where R2 is chosen from the group including C16 to C22 fatty acyl groups, R3 is chosen from the group comprising H or R2, n is 2 or 3 and x is from 0 to 120.

2. A pearlescent based concentrate according to claim 1 comprising:
between 5 and 40% by weight of the composition of alkylpolysaccharide of formula H-Gx-OR1 where R1 is selected from the group comprising linear or branched C6 to C22 alkyl or alkenyl group where G is selected from the group comprising a C5 or C6 saccharide and x is from 1 to 10;

between 3 and 30% by weight of the composition of alkyl sulphate and/or alkyl ether sulphate;

and between 5 and 20% by weight of pearlescing acid of formula R COOH
where R is chosen from the group including C16 to C22 alkyl groups,

3. A pearlescent based concentrate comprising:
between 5 and 40% by weight of the composition of alkylpolysaccharide of formula H-Gx-OR1 where R1 is selected from the group comprising linear or branched C6 to C22 alkyl or alkenyl group where G is selected from the group comprising a C5 or C6 saccharide and x is from 1 to 10;
between 3 and 30% by weight of the composition of alkyl sulphate and/or alkyl ether sulphate;
and between 5 and 20% by weight of pearlescing esters of formula R2-(OCnH2n)x-OR3 where R2 is chosen from the group including C16 to C22 fatty acyl groups, R3 is chosen from the group comprising H or R2 , n is 2 or 3 and x is from 1 to 120.

4. A pearlescent based concentrate according to claim 3 which further includes secondary alkane sulphonates of the formula R4-CH(CH3)SO3M
where R4 is chosen from the group comprising C6 to C22 alkyl groups and M is chosen from the group comprising alkali salts.

5. A pearlescent based concentrates according to claim 3 wherein said fatty alcohol ethoxylate is of formula R5(OC2H4)y OH
where R5 is chosen form the group including C6 and C22 alkyl or alkenyl groups and y is from 1 to 120.

6. A pearlescent based concentrate according to claim 3 which further includes between 0 and 30% by weight of the composition of one or more optional additives chosen from the group including:
alkylsulphosuccinate or polyoxyalkylenealkylsulphosuccinate of the formula R6-O-[CH(R7) CH2O]n-[COCH(SO3M)CH2COOM1]
where R6 is chosen from the group including C8 to C20 linear or branched alkyl groups, R7 is H or CH3, M and M1 are independently chosen from the group comprising alkali metals, alkaline earth metals, NH4+, C1 to C3 alkyl groups, substituted ammonia and hydroxy substituted C2 or C3 alkyl substituted ammonia and n is from 0 to 8;
sorbitan fatty acid esters of formula, CH2-(CHOH)3-CHOCH2OR8 where R8 is chosen from the group including C12 to C18 alkyl group;
secondary alkane sulphonates; fatty alcohol alkoxylates;
fatty acid alkoxylates; fatty alcohols; alkanoyl N-methylglucamides; ether carboxylic acids; ethoxylated sorbitan fatty acid esters; and alpha-olefin sulphonates.

7. A pearlescent based concentrate according to claim 3 which further includes fatty alcohols of the formula where R9 is chosen from the group comprising C6 to C22 alkyl groups.

8. A pearlescent based concentrate according to claim 3 which further includes alkanoyl N-methylglucamides of the formula where R10 is chosen from the group consisting C6 and C22 alkyl groups.

9. A pearlescent based concentrate according to claim 3 which further includes ether carboxylic acids of the formula R11C(O)O(C2H4O)mH
where R11 is chosen from the group including C6 to C22 alkyl groups and m is from 1 to 120.

10. A pearlescent based concentrate according to claim 3 which further includes ethoxylated sorbitan fatty acid esters of the formula where R12 is chosen from the group comprising C6 to C22 alkyl groups and w, v, u, t are from 4 to 20

11. A pearlescent based concentrate according to claim 3 which further includes alpha-olefin sulphonates of formula R13CH = CHCH2SO3M2 where R13 is chosen from the group comprising C6 to C22 alkyl groups and M2 is chosen from the group comprising Na & K.

12. A pearlescent based concentrate according to claim 3 comprising between 0 and 2% of the weight of the composition of inorganic salt.

13. A pearlescent based concentrate according to claim 12 wherein said inorganic salt is an alkali metal halide salt.

14. A pearlescent based concentrate according to claim 3 comprising between 10 and 90% of the weight of the composition of solvent.

15. A pearlescent composition comprising a pearlescent based concentrate according to any of the previous claims and at least one solvent in the ratio of between 10:90 and 90:10 weight %.

16. A pearlescent based concentrate according to claim 1 or 2 which further includes secondary alkane sulphonates of the formula R4-CH(CH3)SO3M
where R4 is chosen from the group comprising C6 to C22 alkyl groups and M is chosen from the group comprising alkali salts.

17. A pearlescent based concentrates according to claim 1 or 2 wherein said fatty alcohol ethoxylate is of formula R5(OC2H4)y OH
where R5 is chosen form the group including C6 and C22 alkyl or alkenyl groups and y is from 1 to 120.

18. A pearlescent based concentrate according to claim 1 or 2 which further includes between 0 and 30% by weight of the composition of one or more optional additives chosen from the group including:
alkylsulphosuccinate or polyoxyalkylenealkylsulphosuccinate of the formula R6-O-[CH(R7)CH2O]n-[COCH(SO3M)CH2COOM1]
where R6 is chosen from the group including C8 to C20 linear or branched alkyl groups, R7 is H or- CH3, M and M1 are independently chosen from the group comprising alkali metals, alkaline earth metals, NH4+ C1 to C3 alkyl groups, substituted ammonia and hydroxy substituted C2 or C3 alkyl substituted ammonia and n is from 0 to 8;
sorbitan fatty acid esters of formula, CH2-(CHOH)3-CHOCH2OR8 where R8 is chosen from the group including C12 to C18 alkyl group;

secondary alkane sulphonates; fatty alcohol alkoxylates;
fatty acid alkoxylates; fatty alcohols; alkanoyl N-methylglucamides; ether carboxylic acids; ethoxylated sorbitan fatty acid esters; and alpha-olefin sulphonates.

19. A pearlescent based concentrate according to claim 1 or 2 which further includes fatty alcohols of the formula where R9 is chosen from the group comprising C6 to C22 alkyl groups.

20. A pearlescent based concentrate according to claim 1 or 2 which further includes alkanoyl N-methylglucamides of the formula where R10 is chosen from the group consisting C6 and C22 alkyl groups.

21. A pearlescent based concentrate according to claim 1 or 2 which further includes ether carboxylic acids of the formula R1C(O)O(C2H4O)mH
where R11 is chosen from the group including C6 to C22 alkyl groups and m is from 1 to 120.

22. A pearlescent based concentrate according to claim 1 or 2 which further includes ethoxylated sorbitan fatty acid esters of the formula where R12 is chosen from the group comprising C6 to C22 alkyl groups and w, v, u, t are from 4 to 20

23. A pearlescent based concentrate according to claim 3 which further includes alpha-olefin sulphonates of formula R13CH = CHCH2SO3M2 where R13 is chosen from the group comprising C6 to C22 alkyl groups and M is chosen from the group comprising Na & K.

24. A method of preparing a pearlescent based concentrates of any of claims 3 to 15 comprising the steps of;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present and stirring to form a homogeneous solution, and (b) cooling the stirring solution to a temperature of between 35°C and 45°C at a maximum cooling rate of 15°C/hour.

25. A method of preparing a pearlescent based concentrates of any of claims 3 to 15 comprising the steps of;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present while stirring vigorously to form a homogeneous solution, (b) rapidly cooling the stirring solution to between 60°C and 70°C, and (c) cooling the stirring solution to a temperature of between 35°C and 45°C at a maximum cooling rate of 15°C/hour.

26. A method of preparing a pearlescent based concentrates of any of claims 1, 2 or 16 to 23 comprising the steps of;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present and stirring to form a homogeneous solution, and (b) cooling the stirring solution to a temperature of between 35°C and 45°C at a maximum cooling rate of 15°C/hour.

27. A method of preparing a pearlescent based concentrates of any of claims 1, 2 or 16 to 23 comprising the steps of;
(a) heating the components to a temperature above the highest melting point of the components but less than the boiling point of any solvents present while stirring vigorously to form a homogeneous solution, (b) rapidly cooling the stirring solution to between 60°C and 70°C, and (c) cooling the stirring solution to a temperature of between 35°C and 45°C at a maximum cooling rate of 15°C/hour.

28. A pearlescent based concentrate substantially as herein described with reference to the examples.

29. A method of preparing a pearlescent based concentrate as herein described with reference to the examples.