WO1997003640A1

WO1997003640A1 - Hair styling method employing metal salts

Info

Publication number: WO1997003640A1
Application number: PCT/EP1996/002788
Authority: WO
Inventors: Peter Christopher Konidaris
Original assignee: Unilever NV
Current assignee: Unilever NV
Priority date: 1995-07-21
Filing date: 1996-06-22
Publication date: 1997-02-06
Anticipated expiration: 1998-01-21
Also published as: AU6416996A; GB9515373D0

Abstract

A hair styling and restyling process comprising the steps of: (i) contacting hair with a reducing agent, followed by rinsing; (ii) in conjunction with the reconfiguration of the hair, contacting the hair with a composition comprising from 1 to 40 % by weight of an ionisable metal salt solution in which the metal has a valency of at least 2, and rinsing and drying the hair; (iii) restyling the hair when desired by contacting the hair, in conjunction with the reconfiguration thereof, with a restyling solution having a pH of from about 2 to 8.5, which solution optionally comprises from 1 % to 40 % of an ionisable metal salt in which the metal has a valency of at least 2.

Description

HAIR STYLING METHOD EMPLOYING METAL SALTS

This invention relates to methods for the styling of hair, more particularly those methods in which the hair fibre chemically interacts with at least one species of metal ion.

BACKGROUND AND PRIOR ART

Permanent waving of hair is well known and usually comprises reduction of disulphide groups followed by realignment of sulphydryl groups to give a degree of set and then re- oxidation of free sulphydryl groups to complete the process.

For example, US 5 051 252 describes permanent waving compositions comprising an aqueous chlorite solution which is stabilised by combination with a divalent metal ion and a buffer salt. EP 134 452A describes an acidic permanent wave neutralizer and oxidising composition comprising a polyvalent metal salt and an oxidising agent. GB 2 153 865A describes a composition and process for restructuring hair where the hair is contacted with a reducing solution comprising a mercaptan, and then with a protein flow solution comprising a polyvalent ion in a pH of preferably 6 to 7. The hair is then re- oxidised to give a permanent style. JP 55 009 016 describes a hair rinse composition to help preserve waved hair containing a quaternary ammonium salt and zinc sulphate. JP 61 007 210 describes an agent for the deformation of hair comprising a divalent metal salt at an alkaline pH.

A problem with such permanent styling is that it cannot be varied according to day to day wishes and it is a harsh process which can damage the hair. An alternative is temporary styling, which takes the form of various sprays, mousses and gels which are applied to the hair after washing. These products are designed to be washed out and may not be very durable, especially in humid atmospheres. Furthermore, the products can have unwelcome sensory negatives due to the deposition of relatively large quantities of polymers and other synthetic materials on the hair.

It is an object of the present invention to provide a treatment of the hair which reduces the sensory negatives associated with conventional temporary styling methods and moreover gives a durable style which can nevertheless be repeatedly changed or even removed according to the wishes of the user. Thus the hair can be straight during the day and curly in the evening or for the weekend.

Reversible styling of hair is disclosed by K.E.Hall and .J. olfram, J Cosmet Chem, 1977, 28, 231-241. They reduce the disulphide bonds within the hair fibre and react the newly formed sulphydryl groups with an alkyl halide. This two step treatment has the effect of introducing hydrophobic groups within the fibre giving rise to an increase in the number hydrophobic bonds present thus leading to retention of set. This technology suffers from safety considerations regarding the alkylation step and does not give sufficient style retention for modern requirements.

We have found that the introduction of metal-sulphur bonds into the hair permits a process by which the hair can be durably styled and then easily restyled as desired. This is unexpected because systems incorporating metal ions have previously only been described in the context of permanent, non-reversible hair set retention. SUMMARY OF THE INVENTION

According to the present invention there is provided a hair styling and restyling process comprising the steps of :

(i) contacting hair with a reducing agent, and rinsing,

(ii) in conjunction with the reconfiguration of the hair, contacting the hair with a composition comprising from 1 to 40% by weight of an ionisable metal salt in which the metal has a valency of at least 2, and rinsing and drying the hair;

(iii) restyling the hair when desired by contacting the hair, in conjunction with the reconfiguration thereof, with a restyling solution having a pH of from about 2 to about 8.5, which solution optionally comprises from 1% to 40% by weight of an ionisable metal salt in which the metal has a valency of at least 2.

DETAILED DESCRIPTION OF THE INVENTION

The step of contacting the hair with a reducing agent may be carried out according to conventional perming techniques as are known in the art. The preferred reducing agent is thioglycollic acid or a thioglycollate, most preferably ammonium thioglycollate. The ability to restyle the hair a number of times without the need to repeat the harsh thioglycollate treatment used in the perming process is very desirable, especially when the style is more resistant to moisture and humidity than a water wave.

Reconfiguration of the reduced hair, typically by conventional mechanical methods such as winding onto curlers or rollers, may suitably take place before contacting the hair with the composition of step (ii) . The hair is then rinsed and dried. Alternatively, the hair may be contacted with the composition of step (ii) , rinsed, reconfigured and then dried.

In the composition of step (ii) , examples of suitable ionisable metal salts include salts of non-oxidising divalent metal cations for example Zn²⁺, Mg²⁺, Ca²⁺, Mn²⁺, and Co²⁺, preferably Zn²*, Mg²⁺ and Ca²⁺. By "non-oxidising" is meant that the standard redox potential of the metal ion is less than that of the cysteine-cystine redox couple within the hair. Particularly preferred are organic acid salts such as acetates and pyrrolidonecarboxylates. Strongly chelating acid salts, such as citrates, are less preferred. Zinc acetate is the most preferred species, since zinc salts are typically colourless and odourless with a good safety profile. Zinc is also thought to offer a protective effect against future hair damage. Without wishing to be bound by theory, it is believed that zinc ions form strong, yet flexible interactions with the sulphur atoms of hair keratin, offering a restyling capability which resists repeated shampooing.

The ionisable metal salt may suitably be in aqueous or alcoholic solution, eg propanol, and is preferably contacted with the hair at room temperature. The concentration of the metal salt solution is preferably from 1% to 20%, most preferably 2% to 10% by weight based on total weight, eg 3%, and the contact time about 15 to 60 minutes, eg 30 minutes.

The restyling step (iii) can be repeated as often as required, and there is no need to repeat the step of contacting the hair with a reducing agent. This is especially advantageous since over exposure of the hair fibre to reducing agents is avoided and the risk of hair damage is thus minimised. The restyling solution may suitably comprise a solution of a weak acid, e.g. acetic acid, or a solution of a weak acid in combination with an ionisable metal salt of the type as is hereinabove described, eg zinc acetate. Alternatively, the restyling solution may be water alone, or aqueous propanol.

The pH of the restyling solution is preferably from 4 to 7.5, eg 4.8. A pH below about 3.5 is less preferred since this will tend to produce leaching of the metal ions from the system. Also preferably avoided in the restyling solution is the presence of substantial quantities of chelating agents, such as EDTA, citric acid and tartaric acid.

Reconfiguration of the hair, for example by winding onto curlers or rollers, can suitably be carried out before or after treatment with the restyling solution.

The invention further provides the use of a composition comprising from 1 to 40% by weight of an ionisable metal salt in which the metal has a valency of at least 2 in a hair styling and restyling process.

The composition is preferably used in step (ii) and/or step (iii) of the hair styling and restyling process as is hereinabove described.

Preferably the composition comprises a salt of zinc, calcium or magnesium, more preferably a salt of zinc, most preferably zinc acetate, in an aqueous or alcoholic solution.

Compositions for use in the styling and restyling process of the invention may suitably be formulated into hair cosmetics, e.g. a lotion, shampoo, conditioner or rinse. Such compositions may be provided in any suitable physical form, for example as low to moderate viscosity liquids, milks, mousses, sprays, gels and creams, and may further comprise conventionally known components within such a range that they do not interfere with the operation of the process of the invention. Preferred hair styling and restyling compositions in accordance with the invention are shampoos and conditioners, mousses, sprays and gels.

Preferred hair styling and restyling compositions of the invention comprise one or more surfactant materials.

Shampoo compositions in accordance with the present invention comprise one or more surfactants selected from anionic, nonionic, amphoteric, zwitteronic and cationic surfactants and mixtures thereof.

Suitable anionic surfactants are the alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, alkyl succinates, alkyl sulphosuccinates, N-alkoyl sarcosinates, alkyl phosphates, alkyl ether phosphates, alkyl ether carboxylates, and 0- olefin sulphonates, especially their sodium, magnesium, ammonium, and mono-, di- and tri-ethanolamine salts. The alkyl groups generally contain from 8 to 18 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether phosphates and alkyl ether carboxylates may contain from 1 to 10 ethylene oxide or propylene oxide units per molecule, and preferably contain 2 to 3 ethylene oxide units per molecule.

Examples of further suitable anionic surfactants include sodium oleyl succinate, ammonium lauryl sulphosuccinate, ammonium lauryl sulphate, sodium dodecylbenzene sulphonate and sodium M-lauryl sarcosinate. The most preferred anionic surfactants are sodium lauryl sulphate, triethanolamine lauryl sulphate, triethanolamine monolauryl phosphate, sodium lauryl ether sulphate 1EO, 2EO and 3EO, ammonium lauryl sulphate and ammonium lauryl ether sulphate 1EO, 2EO and 3EO. The nonionic surfactants suitable for use in the composition of the invention may include condensation products of aliphatic (C₈-C₁₈) primary or secondary linear or branched- chain alcohols or phenols with alkylene oxides, usually ethylene oxide and generally 6-30 EO groups.

Other suitable nonionics include mono- or di-alkyl alkanolamides or alkyl polyglucosides. Examples include coco mono- or di-ethanolamide, coco mono-isopropanolamide, and coco di-glucoside.

The amphoteric surfactants suitable for use in the composition of the invention may include alkyl amine oxides, alkyl betaine, alkyl amidopropyl betaine, alkyl sulphobetaines, alkyl glycinates, alkyl carboxglycinates, alkyl amphopropionates, alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates wherein the alkyl and acyl groups have from 8 to 18 carbon atoms. Examples include lauryl amine oxide, cocodimethyl sulphopropyl betaine and preferably lauryl betaine, cocamidopropyl betaine and sodium cocamphopropionate.

Examples of cationic surfactants include: quaternary ammonium salts such as halides, for example cetyl trimethylammonium chloride, stearyl dimethybenzyl ammonium chloride, cetylpyridinium chloride, quaternium-5, -31, -18 and mixtures thereof.

The level of surfactant materials, if present, in compositions of the invention is preferably more than 1%, more preferably 2-35% and most preferably from 5 to 30% by weight of the composition.

Hair styling and restyling compositions in accordance with the invention may comprise one or more hair conditioning agents .

Suitable conditioning agents are the cationic surfactants mentioned above, which may be present in an amount of from 0.01 to 10%, preferably 0.05 to 5%, most preferably 0.1 to 2% by weight of the composition.

Alternative or additional conditioning agents include cationic polymers, volatile or non-volatile silicones, quatemized silicones (eg those materials available under the trade name ABILQUAT ex T.H. Godlschmidt) , perfluoropolyethers (eg those materials available under the trade name FOMBLIN ex Montefluos) , protein hydrolysates and quaternised protein hydrolysates.

Suitable cationic polymers include Guar

Hydroxypropyltrimonium chloride, Polyquaternium-19, -23, -40, -57, poly (dimethyldiallylammonium chloride), Poly (dimethyl butenyl ammonium chloride)-, w- bis (triethanolammonium chloride) , Poly (dipropyldiallylammonium chloride, Poly (methyl-beta-propaniodiallylammonium chloride) , Poly (diallylpiperidinium chloride) , Poly (vinyl pyridinium chloride) , quaternised poly (vinyl alcohol) , quaternised poly (dimethylaminoethylmethacrylate) and mixtures thereof.

Example of suitable silicones include those available commercially from Dow Corning as 244, 245, 344, 345 and 200 fluids (cyclopolymethylsiloxane blends) , 200/5 fluid (a very short linear polydimethylsiloxane) and 1401 fluid (a mixture of polydimethylsiloxanol gum in cyclopolymethylsiloxanes) ; from Union Carbide as TP503 fluid (an emulsion of polydimethylsiloxane gum in cyclopolymethylsiloxane) and Silicone 7202 and 7158; and from Stauffer Chemical as SWS- 03314. Suitable protein derivatives include lauryl dimonium hydroxy propylamino hydrolysed animal protein, available commercially under the tradename LAMEQUAT L, and hydrolysed keratin containing sulphur-bearing amino acids, available commercially under the tradename CROQUAT WKP.

Conditioning agents which are especially suitable for use in compositions according to the invention include volatile or non-volatile silicone oils, for example polyalkylsiloxanes, polyalkylaryl siloxanes, silicone gums, cyclomethicones and aminofunctional silicones. Preferably these silicone materials are incorporated in the compositions as small particles, preferably of particle size 0.01 to 10 microns.

The preferred level of the alternative or additional conditioning agents, if present, in compositions of the invention is up to 20%, for example from 0.01 to 10%, more preferably from 0.1 to 5% by weight.

Another ingredient that may advantageously be incorporated into the hair styling and restyling compositions of the invention is a fatty alcohol material. The use of such a material especially preferred in conditioning compositions, in particular conditioning compositions which comprise one or more cationic surfactant materials. The combined use of fatty alcohol material and cationic surfactant in conditioning compositions is believed to be especially advantageous, because this leads to the formation of a lamellar phase, wherein the cationic surfactant is dispersed.

Preferred fatty alcohols contain from 8 to 22 carbon atoms, more preferably 16 to 20. Examples of preferred fatty alcohols are cetyl alcohol and stearyl alcohol. The use of these materials is also advantageous in that they contribute to the overall conditioning properties of the compositions of the invention.

The level of fatty alcohol material is conveniently from 0 to 10%, more preferably from 0.1 to 5% by weight of the composition. The weight ratio of cationic surfactant to fatty alcohol may preferably be from 10:1 to 1:10, more preferably from 4:1 to 1:8, most preferably from 1:1 to 1:4.

OTHER INGREDIENTS

The hair styling and restyling compositions of the invention may also include minor amounts of other ingredients commonly found in hair treatment compositions, e.g. antibacterial agents, anti-dandruff agents such as zinc pyridinethione, foam boosters, pearlescers, perfumes, dyes, colouring agents, preservatives, viscosity modifiers, proteins, polymers, buffering agents, polyols and other moisturising agents, herb extracts, mink oil or honey.

Compositions for use in the process of the invention may suitably be supplied to customers in kit form, for example, where the kit contains packages of compositions comprising reducing agent and ionisable metal salt solution respectively, with a composition comprising restyling solution in association therewith. Each packaged composition may advantageously be formulated into a hair cosmetic with any of the ingredients as are hereinabove described. Alternatively, the packaged compositions for use in the process of the invention may be sold separately. The packaging may typically be in the form of sachets, capped plastic bottles, or spray bottles or the like.

The invention will now be further illustrated by way of the following non-limiting Examples, in which: Figure 1 is a graph showing, at high (80%) humidity, the curl retention against time after initial styling with a composition according to the invention, as compared with a waterwave.

Figure 2 is a graph depicting hair volume (measured as interfibre spacing) and hair lift data measured for bobbed hair restyled with a composition according to the invention, as compared with a waterwave.

EXAMPLES;

All percentages are by weight unless otherwise specified.

10 fibre hair switches were prepared by knotting together 10 hair fibres 15cm long. The switches were wound onto curlers and then treated with the following reducing solution for 25 minutes.

Ingredient

Ammonium thioglycollate 6

Ammonia solution (to pH 9.3)

Water to 100%

30g of the following treatment solution was then applied to the switches for 15 minutes, followed by an additional 30g of solution for a further 15 minutes:

Ingredient

Zinc Acetate Dihydrate 3

Acetic Acid to 0.01M

Formaldehyde (40%) 0.1 Aqueous propanol to 100% The hair was then rinsed, styled on curlers and dried. The percentage retention of initial curl length was then evaluated against a control using the ammonium thioglycollate reducing solution alone. Curl retention was determined by measuring the distance of curl fall-out after soaking the switches in water for 5 minutes. The results are shown in Table 1:

Table 1

PERCENTAGE CURL RETENTION (%)

CONTROL 45 (1.8) *

EXAMPLE 1 79 (1.6)

Standard deviations are given in brackets.

The hair was then restyled onto curlers, treated with the following solution and then dried:

Ingredient

%

Zinc Acetate Dihydrate 3 Acetic Acid to 0.1 M

Formaldehyde (40% active) 0.1 Aqueous propanol to 100%

The percentage curl retention was again evaluated, as earlier described against a control using the initial ammonium thioglycollate reducing solution alone. The results are shown in Table 2 : Table 2

PERCENTAGE CURL RETENTION (%)

CONTROL 46.1 (6.2)

EXAMPLE 1 88.8 (3.8)

EXAMPLE 2

In this case, the procedure of Example 1 was followed, except that the solutions used for the styling and restyling of the reduced hair were applied to the hair before rinsing, winding onto curlers and drying. Table 3 shows the percentage retention of initial curl length (evaluated as discussed before) , following restyling, as compared with reducing solution alone.

TABLE 3

PERCENTAGE CURL RETENTION (%)

CONTROL 26.3 (2.4)

EXAMPLE 2 79.1 (2.1)

It can be seen from Examples 1 and 2 how treatment with zinc acetate gives improved curl retention following restyling as compared with the control.

EXAMPLE 3

The procedure of Example 2 was followed, but replacing zinc with other metal ions. Table 4 shows percentage curl retention results for these species following restyling as described, compared with controls using reducing solution alone and monovalent metal cation (K⁺) .

TABLE 4

PERCENTAGE CURL RETENTION (%)

METAL ION

Mg ²⁺ 81.1 (5.1)

Mn ²⁺ 79.9 (1.9)

Ba ⁺ 62.9 (13.8)

Ca ²⁺ 55.3 (8.7)

Control (K⁺) 44.7 (11.5)

Control (Reducing 26.5 (5.0) solution alone)

It can be seen how the divalent metal cations tested give superior restyling performance to the controls.

EXAMPLE 4

A small wig was wound into curls. One side was styled into curls, and then restyled (to a bob) using the procedure described in Example 1, and the other side simply waterwaved.

Figure 1 shows, at high (80%) humidity, the curl retention against time after initial styling for the two treatments. It can be seen how the zinc acetate treated hair displays a significantly slower rate of curl loss. Figure 2 shows hair volume (as interfibre spacing) and hair lift data as measured for the restyled, bobbed hair. It can be seen how the zinc acetate restyled hair retains these properties significantly longer than the waterwaved side.

Claims

1. A hair styling and restyling process comprising the steps of:

(i) contacting hair with a reducing agent, followed by rinsing,

(ii) in conjunction with the reconfiguration of the hair, contacting the hair with a composition comprising from 1 to 40% by weight of an ionisable metal salt solution in which the metal has a valency of at least 2, and rinsing and drying the hair,

(iii) restyling the hair when desired by contacting the hair, in conjunction with the reconfiguration thereof, with a restyling solution having a pH of from about 2 to 8.5, which solution optionally comprises from 1% to 40% of an ionisable metal salt in which the metal has a valency of at least 2.

2. A process according to claim 1 in which the ionisable metal salt comprises a non-oxidising divalent metal cation, preferably Zn²⁺, Mg²⁺ or Ca²⁺.

3. A process according to any preceding claim in which the ionisable metal salt is zinc acetate.

4. A process according to any preceding claim in which the restyling solution has a pH of from 4 to 7.5.

5. A process according to any preceding claim in which the restyling solution comprises acetic acid.

6. A process according to claim 5 in which the restyling solution further comprises zinc acetate.

7. The use of a composition comprising from 1 to 40% by weight of an ionisable metal salt in which the metal has a valency of at least two in a hair styling and restyling process according to any preceding claim.

8. The use according to claim 7 in which the ionisable metal salt is zinc acetate.

9. The use according to claim 7 or claim 8, in which the composition is formulated as a hair cosmetic.

10. A kit for the styling and restyling of hair comprising:

(i) a packaged composition comprising reducing agent for the hair;

(ii) a packaged composition comprising from 1 to 40% by weight of an ionisable metal salt in which the metal has a valency of at least 2;

(iii) in association therewith, a packaged composition comprising a restyling solution for the hair having a pH of from about 2 to about 8.5, which solution optionally comprises from 1% to 40% by weight of an ionisable metal salt in which the metal has a valency of at least 2.

11. The use of an ionisable metal salt in which the metal has a valency of at least 2 in a process for the preparation of a composition for use in a hair styling and restyling process according to any one of claims 1 to 9.