CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application No. 10 2018 218 945.5, filed Nov. 7, 2018, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure is in the field of cosmetics and relates to a method of reducing damage in the chemical treatment of keratinic fibers, in which a cosmetic composition is applied to keratinic fibers as a pretreatment agent prior to the chemical hair treatment.

BACKGROUND

Hair can be damaged by natural or artificially induced processes. The natural processes can, for example, have a combined (for example, simultaneous) action of UV light and oxygen (O2) on the hair. The artificially induced processes can comprise, for example, applying hair dye (also referred to as colorations), bleaching and/or generating a permanent wave.

In addition to desirable cosmetic effects, such as a lightening of the hair, it is also possible for severe damage to the hair to occur, for example, when using oxidizing agents.

The resulting damage type is called oxidative damage and is caused by the use of colorations, bleaching, permanent waving and also by environmental influences (UV+O2). This damage is caused by the oxidation of the amino acids cystine and cysteine, which are common in the hair, to cysteic acid.

Cystine can form intermolecular disulfide bridges (also called SS bridges) in the hair, so that the cystine is extremely important for the mechanical stability of the hair.

Oxidation of these bridges to cysteic acid can destroy the mechanical stability of the hair and even lead to complete hair breakage with multiple applications. However, previously macroscopically perceptible, for example, tangible, properties of the hair, for example, a surface roughness, can be negatively influenced.

In addition to this oxidative damage, reductive damage to the hair is also possible. This occurs in cosmetic methods that use reducing agents. These are, for example permanent waves or chemical smoothing methods, which contain reducing agents such as thioglycolic acid or sulfite. These ingredients are used to open the disulfide bridges of cysteine for the purpose of reshaping the hair. The following sulfur species are formed in this case: R—S—H (thiols), R—S—SO3−, (bunte salts, after sulfite treatment), R—S—S—CH2COO−(disulfides with thiglycolate units, after thioglycolate treatment).

A method for oxidative hair treatment is known from EP 1923048 A1 in which a cosmetic agent containing a plant extract combination from at least two different plant extracts is first applied to keratinic fibers and then an oxidative cosmetic agent containing an oxidizing agent is applied. Pre-treatment with the cosmetic agent containing a plant extract combination reduces the oxidative damage caused by the use of the oxidizing agent.

However, the methods known in the art do not always result in a desired degree of reduced hair damage.

BRIEF SUMMARY

Methods for the chemical treatment of keratinic fibers are provided. In an exemplary embodiment, a method for the chemical treatment of keratinic fibers includes: i.) applying a cosmetic composition to the keratinic fibers as a pretreatment; and ii.) chemically treating the keratinic fibers with an oxidizing agent and/or a reducing agent within a period of from about 5 seconds to about 24 hours after step i.) The cosmetic composition includes a polyorganosiloxane of formula (I) from about 0.1 to about 4.0 weight percent.



Another method of chemically treating keratinic fibers is provided in another embodiment. The method includes applying a cosmetic composition to the keratinic fibers as a pretreatment, wherein the cosmetic composition includes Amodimethicone/Morpholinomethyl Silsesquioxane Copolymer. The cosmetic composition is left on the keratinic fibers at least until the keratinic fibers are chemically treated with an oxidizing agent, where the keratinic fibers are chemically treated within about 5 seconds to about 24 hours after the pretreatment. A further cosmetic composition is applied to the keratinic fibers as a post-treatment after the chemical treatment, where the further cosmetic composition has a pH of from about 3 to about 5, and includes a metal salt selected from strontium salts, zirconium salts, hafnium salts, titanium salts, tin salts, aluminum salts, bismuth salts, lanthanum salts, calcium salts, magnesium salts, and mixtures thereof.

