WO1995003782A1

WO1995003782A1 - Pearlescent based concentrate for personal care products

Info

Publication number: WO1995003782A1
Application number: PCT/AU1994/000421
Authority: WO
Inventors: Katherine Margaret Wansborough; Anne Maree Lombard; Pamela Joyce Jones
Original assignee: Ici Australia Operations Proprietary Limited
Priority date: 1993-07-28
Filing date: 1994-07-26
Publication date: 1995-02-09
Also published as: CA2168346A1; KR960703565A; NZ269755A

Abstract

A pearlescent based concentrate and method of preparation wherein the concentrate 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

PEARLESCENT BASED CONCENTRATE FOR PERSONAL CARE PRODUCTS

The invention relates to pearlescent based concentrates comprising at least one al ylpolysaccharide, 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 (Priority 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. 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 C₁₂ to C₂₂ fatty acids.

One of the disadvantages of the pearlescent based concentrates of the prior art is that they often comprise chemicals 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 o human skin.

Generally, the order of increasing human skin irritatio 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. 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

H-G_χ-OR¹ where R 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-(°C_nH_2n)_χ-OR³ where R is chosen from the group including C₁₆ to C₂₂ fatty acyl groups, R 3 is chosen from the group comprising H or R2, n is 2 or 3 and x is from 1 to 120.

The current invention further provides a pearlescent based concentrate including: H-G_χ-0R¹ where R 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 to 20% by weight of pearlescing acid of formula R COOH where R is chosen from the group comprising C₁₆ 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

R⁴ - 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

R⁵ (OC₂H₄)_y OH where R⁵ is chosen from the group including

C₆ and C₂₂ alkyl or alkenyl groups and y is from 1 to 120 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

R⁶-0-[CH(R⁷)CH₂0]_n-[COCH(S0₃M)CH₂COOM¹] where R is chosen from the group including C₈ to C₂₀ linear or branched alkyl groups, R⁷ is H or CH₃,

M and M are independently chosen from the group comprising alkali metals, alkaline earth metals, NH₄ ⁺, C_χ 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 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

R⁹OH where R 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 COR¹⁰

CH₃-N-CH₂(CHOH)₄CH₂OH where RR¹¹⁰⁰ is chosen from the group comprising C₆ and C₂₂ alkyl groups In another preferred embodiment the optional additives of the pearlescent concentrate of the current invention includes ether carboxylic acids of the formula R^uC(0)0(C₂H₄0)_πιH where R is chosen from the group includes C₆ to C₂₂ alkyl groups and m is from 1 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

where R 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

R¹³CH = CHCH₂S0₃M² where R 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 10 and 90% of the weight of the composition of water or other suitable solvent. The pearlescent based concentrates of the current invention may also have added optional agents including perfumes, pigments, UV 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 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.

The pearlescent based concentrates of the current 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 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.

The current invention will now be described with reference to the following non-limiting examples; EXAMPLE 1

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

Component Composition (% 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 80°C with vigorous stirring. The solution was maintained at 80°C with stirring for further 30 minutes before being rapidly cooled to 65°C. Once the solution temperature reached 65°C the stirring rate was slowed and the solution cooled at a controlled rate of 10°C per hour until the temperature reached 40°C. The stirrer was then stopped and the pearlescent blend allowed to cool to room temperature.

EXAMPLE 2

Component Com osition (% w/w)

Dodecylpolysaccharide (50% a.i.) Sodium lauryl sulphate (30% a.i.) TERIC 12A23

Ethylene glycol mono-stearate Sodium chloride Water

Method

Ethylene glycol mono-stearate, dodecylpolysaccharide, sodium lauryl sulphate, TERIC 12A23 water and sodium chloride were heated to 80°C with vigorous stirring. Once the solution had reached 80°C, the stirring rate was slowed and the solution cooled at a controlled rate of 10°C per hour until the solution temperature had dropped to 0°C. When the solution temperature had reached 40°C the stirrer was stopped and the pearlescent based composition was allowed to cool to room temperature. (TERIC is a registered trade mark of ICI Australia Operations Proprietary Limited) .

EXAMPLE 3

Component Composition (%w/w)

Decylpolysaccharide (50% a.i.) 37.00

Sodium lauryl sulphate 10.00

Cetyl Stearyl alcohol 5.00

Ethylene glycol monostearate 16.25 Water 32.75

Method

Ethylene glycol monostearate, decylpolysaccharide, sodium lauryl sulphate, cetyl-stearyl alcohol and water were heated to 75°C with vigorous stirring. The solution was cooled until the temperature reached 70°C at which point the rate of cooling was controlled at 15°C/hour and the stirring rate reduced. When temperature reached 40°C, stirring was stopped and the pearlescent based composition allowed to cool to room temperature.

EXAMPLE 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 70°C with vigorous stirring. When the solution temperature reached 70°C the stirring rate was reduced and the solution cooled at a rate of 8°C/hr. When the solution temperature reached 40°C the stirring was stopped and the resultant pearlescent based concentrate left to cool to room temperature.

EXAMPLE 5

Component Composition (%w/w)

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 70°C with rapid stirring then the stirring rate was reduced and the mixture cooled at a rate of 8°C per hour. When the mixture reached 40°C all stirring was ceased.

EXAMPLE 6

Component Composition (%w/w)

Decyl Polysaccharide 25.00 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.

EXAMPLE 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 Method

The above components were combined according to the method of Example 5 to form a pearlescent based concentrate,

EXAMPLE 8

Component Composition (%w/w)

Decyl Polysaccharide Ammonium lauryl sulphate Ethoxylated sorbitan monooleate Sodium Chloride Ethylene glycol monostearate Water

Method

EXAMPLE 9

Component Composition (%w/w)

Decyl Polysaccharide 30.00

Sodium lauryl sulphate 15.00

Stearic acid 15.00 Sodium Chloride 1.00

Water 39.00

Method

EXAMPLE 10

Component om osition (%w/w)

C16-18 Polysaccharide Decyl Polysaccharide Sodium lauryl sulphate Ethylene glycol monostearate Sodium Chloride Water

Method

The above components were combined according to the method of Example 5 to form a pearlescent based concentrate, 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-G^-OR¹ where R 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-(OC_nH_2n)_χ-OR³ where R is chosen from the group including C₁₆ to C₂₂ fatty acyl groups,

R 3 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-G_χ-0R¹ where R 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-G_χ-OR¹ where R 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-(°C_nH_2n)_χ-OR³ where R is chosen from the group including C₁₆ to C₂₂ fatty acyl groups,

R is chosen from the group comprising H or R , 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)S0₃M where R 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

R⁶-0-[CH(R⁷)CH₂0]_n-[COCH(S0₃M)CH₂COOM¹] where R is chosen from the group including C₈ to C₂₀ linear o branched alkyl groups,

R⁷ is H or CH₃, M and M are independently chosen from the group comprising alkali metals, alkaline earth metals, NH₄ ⁺, C₂ 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 R is chosen from the group including C₁₂ to C₁₈ alkyl group; secondary alkane sulphonates; fatty alcohol alkoxylates; fatty acid alkoxylates; fatty alcohols; alkanoyl N- methylgluca ides; 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

R⁹OH 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

COR¹⁰ I CH₃-N-CH₂(CHOH)₄CH₂OH 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

RⁿC(0)0(C₂H₄0)_mH where R 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 R 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

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

17. A pearlescent based concentrates according to claim 1 or 2 wherein said fatty alcohol ethoxylate is of formula

R⁵(OC₂H₄)_y OH where R 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

R⁶-0-[CH(R⁷)CH₂0]_n-[COCH(S0₃M)CH₂COOM¹] where R 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 ⁺, C. 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

R⁹OH where R 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

COR¹⁰

CH₃-N-CH₂ ( CHOH ) ₄CH₂OH where R is chosen from ^•tI- VhΪΩe rgττr-(o-mupτι rcnonnscii' csttii nnπg CC '₆ . 6 a. "n... . . ^{1 ,}d* "C2₂2₂ alkyl groups.

21. A pearlescent based concentrate according to claim 1 or 2 which further includes ether carboxylic acids of the formula

R"C(0)0(C₂H₄0)_BH where R 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 R 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

24. A method of preparing a pearlescent based concentrates of any of claims 3 to 15 comprising the steps of;

25. A method of preparing a pearlescent based concentrates of any of claims 3 to 15 comprising the steps of;

(b) rapidly cooling the stirring solution to between 60°C an 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;

27. A method of preparing a pearlescent based concentrates of any of claims 1, 2 or 16 to 23 comprising the steps of;

(b) rapidly cooling the stirring solution to between 60°C and 70°C, and

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.