Process for relaxing keratin fibres

Abstract

The invention relates to a process for relaxing keratin fibres by applying to the keratin fibres a relaxing composition containing at least one denaturing agent with a molecular mass of greater than 18.1 g/mol, present in a molar concentration of between 1M and 8M, and raising the temperature of the keratin fibres to a temperature of between 110 and 250° C.

Description

REFERENCE TO PRIOR APPLICATIONS [0001] This application claims priority to U.S. provisional application 60 / 646,616 filed Jan. 26, 2005, and to French patent application 0452775 filed Nov. 26, 2004, both incorporated herein by reference.FIELD OF THE INVENTION [0002] The invention relates to a process for relaxing keratin fibres with heat and at least one denaturing agent. [0003] Additional advantages and other features of the present invention will be set forth in part in the description that follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from t...

AI Technical Summary

Benefits of technology

[0035] After extensive studies, it has now been discovered, entirely surprisingly and unexpectedly, that the hair can be durably relaxed by combining the action of a denaturing agent and by heating to a temperature above 110° C. Excellent results in terms of relaxing, hair cosmetic properties and fibre integrity are thus obtained.

Problems solved by technology

Besides the drawback of giving off an unpleasant odour requiring the use of more or less efficient fragrances to mask the odours, the use of a thiol at alkaline pH also leads to degradation of the fibre and most particularly to impairment of artificial colorations.

They have similar drawbacks to thiols, with less efficacy.

Thiols and sulfites (or bisulfites) also have the drawback of having poor stability in aqueous solution.

In general, the durability of the reshaping effects obtained with thiols and sulfites by reduction of disulfides followed by fixing is judged to be very much inferior to that which may be obtained via the lanthionization technique.

However, these hydroxides have the major drawback of being caustic.

This causticity affects the scalp by causing irritation, which may occasionally be severe.

The causticity of hydroxides also affects the condition of the hair by firstly giving it a coarse feel and secondly making it much more fragile, this fragility possibly going as far as flaking or even breaking, or even the dissolution of the hair if the treatment is prolonged.

In certain cases, hydroxides also cause decolorization of the natural colour of the hair.

The presence of this precipitate makes the final rinsing of the hair much more difficult and leaves on the hair and the scalp mineral particles that give it a coarse feel and an unattractive appearance resembling dandruff.

However, these technologies using bases of the hydroxide family remain very aggressive for the hair and the scalp and require very strict control of the application time to avoid excessive irritation and impairment of the hair, which may go as far as breaking of the hair.

Although all these proposals lead to more or less marked improvements, they do not make it possible to significantly reduce the damage caused by the causticity itself of hydroxides.

As indicated above, the use of reducing agents leads to mediocre durability for relaxing or uncurling, and the use of hydroxides, on account of their causticity, limits their use to the field of relaxing.

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