GB2144989A

GB2144989A - Hair relaxing compositions and preparations and use thereof

Info

Publication number: GB2144989A
Application number: GB08416334A
Authority: GB
Inventors: Dwaipayan Chaudhuri
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1983-07-28
Filing date: 1984-06-27
Publication date: 1985-03-20
Also published as: OA07758A; GB2144989B; ZA845473B; KE3784A; CA1234763A; GB8320366D0; GB8416334D0

Abstract

A hair relaxing composition comprises, by weight, (i) 1.0 to 13.0% of ammonium or alkali metal bisulphite, (ii) 5.0 to 11.0% of a combination of polyoxyethylene (POE) 21-stearyl alcohol and one or more other POE non-ionic surfactants, the combination providing at least 1.33% of POE 21-stearyl alcohol and having a calculated HLB of 7 to 9, and/or 0.5 to 1.5% of cetyl trimethylammonium bromide, and (iii) 5.0 to 20.0% of one or more oils, the balance being water, and the composition being in the form of a stable creme emulsion. .

Description

SPECIFICATION Hair relaxing compositions and preparation and use thereof This invention is concerned with hair relaxing compositions, with a process for their preparation, and with their use in the treatment of hair.

Hair waving, hair straightening and hair relaxing are all based on the breaking, rearranging and reforming of keratin protein bonds which are responsible for hair configuration. Affecting natural hair shape by lysing the cystine disulphide linkages of keratin protein is referred to as softening or relaxing the hair. Hair softening chemicals are generally called hair waving agents, but they can equally be used to straighten hair as well. A useful discussion of the state of this art can be found, for example, in European Patent Application 75475A.

The tight curly configuration of negroid hair poses special problems. Until recently, the approach to styling this type of hair has been to straightening it using products based on sodium hydroxide or thioglycollates as the active materials and various hair straightening compositions based on one or other of these active materials are available in the U.S. and African markets. These active materials are relatively harsh in their effect and such compositions, if not properly used, can lead to hair breakage, to loss of hair colour (black hair becoming brown), and to drying of the scalp. Their use involves multiple stages, all of which have to be carefully carried out, and they are therefore generally unsuitable for home use.

In addition, there has been a movement recently in the styling of negroid hair away from a relatively harsh straightening effect to a less drastic effect in which the natural tight curly configuration is loosened or relaxed.

We have now developed bisulphite-based hair relaxing compositions which can be used for the relaxing of negroid hair (and, of course, for the waving of caucasian hair) and which are suitable for use in a one stage process, thus avoiding the multiple stage processing of conventional hair straightening compositions. Our compositions are, therefore, well suited to home use.

While bisulphite-containing hair treatment compositions are known, we believe that our compositions are the first which are adapted for use in a one stage process which does not require any pre-treatment or post-treatment of the hair.

According to the present invention, there is provided a hair relaxing composition, which comprises, by weight, (i) 1.0 to 13.0% of ammonium or alkali metal bisulphite, (ii) 5.0 to 11.0% of a combination of polyoxyethylene 21-stearyl alcohol and one or more other polyoxyethylene non-ionic surfactants, the combination providing at least 1.33% of POE 21-stearyl alcohol and having a calculated HBL of 7-9, and/or 0.5 to 1.5% of cetyl trimethylammonium bromide, and (iii) 5.0 to 20.0% of one or more oils, the balance being water, and the composition being in the form of a stable creme emulsion As the active material, it is preferred to use ammonium bisulphite, but alkali metal bisulphites, preferably sodium bisulphite, can be used if desired. It is preferred that the composition should contain 7.0% of the active material.

Ammonium bisulphite is conveniently obtained and handled as a 40% aqueous dispersion having a pH of about 7 (adjusted with ammonium hydroxide); if such a dispersion is used as the source of the bisulphite, the composition may contain 2.5 to 32.5% of it, preferably 17.5% As indicated, the emulsifier used to form the emulsion may be a combination of POE nonionic surfactants and/or a particular cationic surfactant, that is cetyl trimethylammonium bromide (which is available under the Trade Mark "Cetavlon"). When the cationic surfactant is used alone, the composition imparts a somewhat harsher feel to the hair than when the nonionic combination is used and it is, therefore, preferred to use the latter alone or in combination with the cationic surfactant.

POE 21-stearyl alcohol is available under the Trade Mark "Brij 721"; other POE non-oinic surfactants which can be used in the non-oinic combination are also available under the Trade Mark "Brij". A preferred other POE non-ionic surfactant is POE 2-stearyl ether ("Brij 72"). As stated above, the non-ionic combination should have a calculated HLB of 7 to 9, preferably 7.5.

POE 21-stearyl alcohol has an HLB of 15.5; POE 2-stearyl ether has an HLB of 4.9 so that it is necessary to use three times as much POE 2-stearyl ether as POE 21-stearyl alcohol to obtain the required overall HLB.

The amounts of this preferred combination of POE 21-stearyl alcohol and POE 2-stearyl ether used in the composition are preferably from 1.33 to 2.66% of POE 21-stearyl alcohol and 4.0 to 8.0% of POE 2-stearyl ether, the amount of each within these ranges being such that the weight ratio of POE 2-stearyl ether to POE 21-stearyl alcohol is about 3. It is most preferred to use 6.0% of POE 2-stearyl ether and 2.0% of POE 21-stearyl alcohol.

When cetyl trimethylammonium bromide is used, it is preferably present in an amount of 1.0%.

The purpose of the oil component of the composition is to facilitate removal of oily residues (whether of natural origin or previously applied) from the hair so as to permit good contact between the active material of the composition, the bisulphite, and the hair and the leave some oil on the hair after treatment to condition the hair. The oil used should, therefore, be suitable for these purposes. Suitable oils include, for example, mineral oils, that is liquid paraffins.

isopropyl myristate, isopropyl palmitate, and natural oils; mixtures of two or more oils can, of course, be used. A preferred oil is the liquid paraffin available under the Trade Mark "Carnation 70".

The amount of oil used is, as stated above, from 5.0 to 20.0%; it is preferred to use about 10.0%.

The composition according to the invention may additionally contain a number of optional ingredients.

(i) Emulsion stabilisers A variety of emulsion stabilisers are known to those skilled in the art and any of them can, in principle, be used in the composition according to the invention given, of course, that they are medically approved for use in a hair care product and are chemically compatible with the other ingredients.

A preferred class of emulsion stabilisers is fatty alcohols containing from 1 4 to 20 carbon atoms, of which cetyl alcohol and stearyl alcohol are particularly preferred. Stearyl alcohol is the more preferred of these two with compositions containing higher levels, that is 7.0% or more, of bisulphite.

Another class of stabilisers which is suitable are the partial esters of glycerol with long chain fatty acids, such as glyceryl monostearate.

The amount of emulsion stabiliser used is suitably from 1.0 to 10.0%, more preferably about 5.0%.

(ii) Thickening agents It is preferred that the composition should be structured, that is thickened, by the inclusion of one or more thickening agents. These may be compatible with the oil phase or the aqueous phase of the emulsion.

A preferred class of oil-compatible thickening agents are cationically treated montmorillonite clays such as those available under the Trade Marks "Bentone 38" and "Bentone 27", of which the first is particularly preferred. Where such a modified clay is used, it is preferred that the composition should also contain a small proportion of a lower aliphatic alcohol or propylene carbonate, the amount of this additive preferably being about half that of the modified clay, for example 0.05 to 0.25%, more preferably 0.1%, of 95% aqueous ethanol or of propylene carbonate. The lower aliphatic alcohol or propylene carbonate serves to de-agglomerate the clay platelets and thus enhance the thickening effect of the modified clay.

Another thickening agent compatible with the oil phase that can be used is aluminium stearate.

Suitable thickening agents which are compatible with the aqueous phase include, for example, sodium carboxymethyl cellulose, hydroxyethyl cellulose, and guar gum.

The amount of thickening agent used is suitably from 0.1 to 1.0%, more preferably about 0.2%.

(iii) Hair swelling agents Hair swelling agents promote the action of the active material, the bisulphite, on the hair.

Suitable hair swelling agents are, for example, isopropyl alcohol and urea.

The amount of hair swelling agent used is suitably from 1.0 to 10.0%, more preferably about 5.0%.

(iv) Others The composition according to the invention may additionally contain one or more colourants which are non-substantive to hair, perfumes, bacaeiiostats, or anti-oxidants. Any such additives should, of course, be one that is medically approved for inclusion in a hair care product.

Suitable additives of these kinds and the amounts in which they are suitably used will be known to those skilled in the art.

The composition according to the invention may be prepared in any convenient way; it is normally preferred to mix the components under high shear conditions. It is preferred to mix and emulsify all the ingredients except the bisulphite at a relatively elevated temperature, for example 70"C, and then to cool the emulsion obtained to a temperature of 40'C or less before adding the bisulphite. If ammonium bisulphite is -,drlqd at a temperature above 45"C, some decomposition occurs with liberation of amrn.

A preferred procedure is as follows: 1. When an oil compatible thickener is used, it is dispersed in the oil with high shear mixing, and when such a thickener is a modified clay, a lower alcohol, such as 95% aqueous ethanol, is added after dispersion of the clay.

2. The surfactant(s) and emulsion stabiliser(s), if used, and any other oil-soluble or oil compatible additive(s) are then added and the mixture is heated to 70"C.

3. When a water-compatible thickener is used, it is dispersed in the water with appropriate mixing and any water-soluble or water-compatible additive(s) is/are added to the dispersion. The aqueous mixture is heated to 70"C.

4. The oil phase, at 70"C, is added to the aqueous phase, at 70"C, using high shear mixing.

5. The resulting emulsion is cooled to 45"C, the bisulphite is added and the mixture is homogenised.

In use, the composition according to the invention is applied to the hair (with the latter dry, that is pre-shampooing or pre-wetting of the hair is neither required nor desirable) and rubbed in, the composition is gently combed through the hair with more composition being added to any areas which are not covered, the hair is patted flat, and the hair is left in this state for 30 to 90 minutes depending on the degree of relaxation required; this period is referred to as the "passive phase". The passive phase is preferably about 60 minutes. However a passive phase lasting longer than 90 minutes is unlikely to cause damage to the hair or scalp. The composition is then rinsed off. No post-treatment, such as neutralisation or reoxidation, is required.

It is found that tight curly hair is substantially relaxed by this treatment and is left in a soft and manageable condition.

It is known that electrolytes, such as the bisulphite active material used in the composition according to the invention, have a destabilising effect on the stability of emulsions. The present invention is based on the discovery of selected surfactants or combinations of surfactants which give a stable emulsion even in the presence of the bisulphite. (The criteria for stability we have chosen for this purpose is that the emulsion should be stable at room temperature and at 45"C for at least three months). In the research leading to the present invention many surfactants, including some that are reputed to be electrolyte stable, were tested in a prototype emulsion and were found not to give emulsions meeting the stability criteria mentioned.The prototype emulsion mentioned had the following composition: Surfactant(s) 6.0 + 1.0% Cetyl alcohol 3.0% Liquid paraffin (Carnation 70) 20.0% Modified clay (Bentone 38) 0.2% 95% aq. ethanol 0.1% Glycerol 4.0% Ammonium bisulphite (as 40% aqueous dispersion, pH 7.0) 17.5% Distilled water to 100 Monoethanolamine q.s. to pH 6.5-7 The surfactants used in ten comparative tests, and their calculared HLB, were as follows: 1. Tegin 90 - HLB 4.5 2. Combination of Tegin 90 (HLB 4.5) anci Brij 78 (HLB 15.3) to give HLB 6.3.

3. Combination of Tegin 90 (HLB 4.5) and Brij 58 (HLB 15.7) to give HLB 6.4.

4. Combination of Tegin 90 (HLB 4.50) and Emulgatoren 2155 (HLB 10.5) to give HLB 7.5.

5. Combination of Tegin M (HLB 3.8) and Tegat S (HLB 16.4) to give HLB 7.5.

6. Combination of Brij 78 (HLB 15.3) and Brij 72 (HLB 4.9) to give HLB 7.5.

7. Combination of Brij 78 (HLB 15.3) and Brij 72 (HLB 4.9) to give HLB 9.0.

8. Combination of Brij 78 (HLB 15.3) and Brij 72 (HLB 4.9) to give HLB 9.6.

9. Brij 30 - HLB 9.7.

10. Combination of Brij 72 (HLB 4,9) and Brij 721 (HLB 15.5) to give HLB 10.0 The chemical natures of the surfactants referred to above are as follows: Tegin 90 . Esters of palmitic and stearic acid Tegin M Glyceryl monostearate Tegat S POE glyceryl monostearate Emulgatoren 2155 : Blend of fatty alcohol polyglycol ethers with stearyl alcohol Brij 30 : POE 4 lauryl ether Brij 58 . POE 20 cetyl ether Brij 72 POE 2 stearyl ether Brij 78 . POE 20 stearyl ether Brij 721 POE 21 stearyl alcohol In each of the comparative tests, the emulsion was prepared by the preferred procedure described above. All the emulsions obtained were found to be unstable after one month at 45"C.

The following examples of compositions according to the invention are given by way of illustration only.

Examples 1-4 Creme emulsions of the following compositions (all percentage by weight) were prepared by the preferred procedure described above: Example 1 2 3 4 Brij 72 6.0 6.0 6.0 3.0 Brij 721 2.0 2.0 2.0 1.0 Cetavlon - - - 1.0 Cetyl alcohol 5.0 - 5.0 5.0 Stearyl alcohol - 3.0 - Carnation 70 10.0 10.0 10.0 10.0 Bentone 38 0.2 0.2 0.2 0.2 95% aq. ethanol 0.1 0.1 0.1 0.1 Amm. bisulphite (40 /0 aq. dis.) 12.5 17.5 17.5 17.5 Isopropyl alcohol - - 5.0 Water to 100 to 100 to 100 to 100 Each of these emulsions was stable on storage both at room temperature and at 45"C for at least three months.

Each composition was used to treat hair in the manner described above and in each case, after rinsing off the composition, the hair was found to be substantially relaxed and in a soft and manaaeable condition.

Claims

1. A hair relaxing composition, which comprises, by weight, (i) 1.0 to 13.0% of ammonium or alkali metal bisulphite, (ii) 5.0 to 11.0% of a combination of polyoxyethylene (POE) 21-stearyl alcohol and one or more other POE non-ionic surfactants, the combination providing at least 1.33% of POE 21stearyl alcohol and having a calculated HLB of 7 to 9, and/or 0.5 to 1.5% of cetyl trimethylammonium bromide, and (iii) 5.0 to 20.0% of one or more oils, the balance being water, and the composition being in the form of a stable creme emulsion.

2. A composition according-to claim 1, which comprises approximately 7.0% of the bisulphite.

3. A composition according to claim 1 or 2, in which the other POE non-ionic surfactant used in combination with the POE 21-stearyl alcohol is POE 2-stearyl ether.

4. A composition according to claim 3, in lnicl) *he composition comprises from 1.33 to 2.66% of POE 21-stearyl alcohol and 4.Q to 8.0% of POE 2-stearyl ether, the amount of each within the ranges specified being such that the weight ratio of POE 2-stearyl ether to POE 21stearyl alcohol is approximately 3.

5. A composition according to claim 3 or 4, which comprises 2.0% of POE 21-stearyl alcohol and 6.0% of POE 2-stesryl ether

6. A composition according tn any of hair 1 to 5, which comprises 1.0% of cetyl trimethylammonium bromide.

7. A composition according to any of claims 1 to 6, in which the oil is a liquid paraffin.

8. A composition according to any of claims 1 to 7, which comprises about 10.0% of oil.

9. A composition according to any of claims 1 to 8, which additionally comprises from 1.0 to 10% of one or more emulsion stabilisers.

10. A composition according to claim 9, in which the emulsion stabiliser is a fatty alcohol having 14 to 20 carbon atoms.

11. A composition according to any of claims 1 to 10, which additionally comprises from 0.1 to 1.0% of one or more thickening agents.

1 2. A composition according to claim 11, in which the thickening agent is a cationically treated montmorillonite clay, aluminium stearate, sodium carboxymethylcellulose, hydroxyethyl cellulose, or guar gum.

1 3. A composition according to claim 12, in which the thickening agent is cationically modified montmorillonite clay and the composition additionally comprises 0.05 to 0.25% of 95% aqueous ethanol or of propylene carbonate.

1 4. A composition according to any of claims 1 to 13, which additionally comprises from 1.0 to 10.0% of one or more hair swelling agents.

1 5. A composition according to claim 14, in which the hair swelling agent is isopropyl alcohol or urea.

16. A hair relaxing composition substantially as herein described in any of Examples 1 to 4.

1 7. A method of relaxing hair, which comprises applying a composition according to any of claims 1 to 1 6 to the hair to be relaxed, maintaining the hair in a configuration appropriate to the desired relaxed effect and in contact with the composition for 30 to 90 minutes, and then rinsing the composition from the hair.