GB591932A - Improvements in and relating to the treatment of hair for permanent waving - Google Patents

Abstract

Hair, particularly human hair, is given a permanent set, or stress is removed therefrom, by treating the hair with an aqueous sulphite solution having a pH value within the range from about pH 6 to pH 8 and containing from 15 per cent to 45 per cent by volume of a water-soluble monohydric alcohol or mixture of alcohols at a temperature below 50 DEG C. The sulphite solution may comprise a mixture of a sulphite and a bisulphite in proportions to give the desired pH value. Sodium or potassium sulphite may be used with lithium or ammonium bisulphite. Approximately equimolecular proportions of sulphite and bisulphite will in general give the specified pH condition. The concentration is preferably within the range of two-thirds to one and one-third gram-molecule of sulphite and bisulphite together per litre. Methyl, ethyl, propyl, or butyl alcohol may be used. The monohydric alcohol may be used in admixture with a glycol such as ethylene glycol. The sulphite solution may contain a surface active agent such as cetyl trimethyl ammonium bromide or cetyl pyridinium bromide. Kieselguhr or gum may be included as thickening agent. For treating human hair on the head, the hair may be washed, dried, wound on curlers and then treated with the sulphite solution or it may be treated with the solution and then wound on curlers or formed into waves or curls. In an example, the hair is treated with a solution containing 63 grams of sodium sulphite, 50 grams of ammonium bisulphite and 300 c.c. of ethyl alcohol per litre. The hair may be covered with a cap and left for 30 to 60 minutes without heating, or it may be heated by air or heated pads for 10-20 minutes at 35-45 DEG C. The hair is then washed and it may be further treated with a solution of a mild oxidizing agent, e.g. peroxide, persulphate, or perborate. This solution may contain a cation-active compound such as cetylpyridinium bromide. Alternatively, the finishing treatment may be effected with a solution of cation-active compound without any oxidizing agent. Specification 456,336 is referred to.