The style guide: 4 patents for hair care

Published: 25-Jul-2018

This collection of patent abstracts brings together one on hair gels; one on hair conditioning and conditioning shampoos; one to restore broken disulfide bonds within a hair shaft; and one on a four-step permanent waving process

From non-tacky styling gels to a new permanent waving process via conditioning shampoos – the following patents showcase the latest breakthroughs in hair care products:

1. Cosmetic composition comprising a fixing polymer and a specific thickener and uses in styling
US Patent 9,833,400
Application No 13/821,047
Granted 5 December 2017
Assignee L’Oréal

The application of conventional styling gels presents problems of tackiness associated with very long drying times.

Additionally, it is often difficult to ensure homogeneous distribution of the polymers over all the hair to obtain a uniform coating feel.

The patent claims to overcome these disadvantages by presenting a hair styling composition comprising one or more cationic fixing polymers and one or more (meth)acrylic thickening polymers in compositions having high levels of alcohol.

The compositions described may be applied without a reduction in viscosity over time, they dry rapidly and without a tacky effect and make it possible to give a natural and long lasting hairstyle.

Drilling down through the multitudes of materials claimed to be suitable as cationic styling polymers, it appears that polyquaternium-4, polyquaternium-46 and hydroxypropyl guar are favoured.

However, anionic styling polymers including acrylates/t-butylacrylamide copolymer and various VP/VA copolymers are also included in the example formulations.

Again, drilling down through the extensive examples of potential anionic thickening polymers, it appears that polyacrylates-14 and 32, polyacrylate-2 crosspolymer, AMP-acrylates/allyl methacrylate copolymer and acrylates/C10-30 alkyl acrylate crosspolymer are preferred.

The alcohol content is at a minimum 75% by weight and the gels may contain perfume, PEG-14 dimethicone, glycols, panthenol and other additives to improve their product claims and aesthetics.

2. Conditioning composition for hair
US Patent 9,616,012
Application No 13/814,110
Granted 13/814,110
Assignee Kao Germany

The patent describes an aqueous conditioning composition for hair comprising at least one cationic starch polymer and at least one additional cationic polymer with monosaccharide units.

The compositions can be shampoos, cleansing-conditioning compositions or conditioners used after washing the hair.

The preferred cationic starch polymer is hydroxypropyl oxidised starch PG trimonium chloride present at up to 2.5% w/w and the preferred additional cationic polymer is guar hydroxypropyltrimonium chloride, also present at up to 2.5% w/w.

This combination is claimed to make hair smooth and to confer improved looseness and bounce. Such effects are especially pronounced when hair is damaged and significantly improved properties were also observed with fine hair.

Smooth hair has enhanced shine and volume, and improved looseness and bounce gives extra body and volume.

The composition further contains silicone compounds, preferably amodimethicone or a derivative thereof, and silicone quaternium-22 with a total concentration up to 2.5% w/w.

Additional conditioning agents including stearyl trimethylammonium chloride, cetrimonium chloride and panthenol are also named.

3. Methods for fixing hair and skin
US Patent 9,855,447
Application No 4/835,223
Granted 2 January 2018
Assignee Liqwd

Hair consists of many long protein chains composed of amino acid building blocks bound to each other via hydrogen bonding, salt bridges between acid and base groups, and disulfide bonds.

Repeated washing with slightly alkaline shampoo, hair colouring with oxidative hair dyes, hair perming or use of heated styling tongs damages the hair by breaking the disulfide bonds.

This causes the cuticle or outer surface of the hair to become rough – hair lacks shine, is difficult to brush or comb and ends may split.

The patent describes compositions, kits and methods for repairing disulfide bonds to provide a long lasting, smooth, moisturised feel with increased tensile strength and ease of combing, and less hair breakage and frizz.

The essential part of the patent is a binding agent that restores broken disulfide bonds and this is added as a solution to the hair prior to shampooing, colouring or other hair treatment process.

Alternatively, it may be added to the actual treatment composition before use.

The binding agent contains at least two reactive moieties capable of reacting with a thiol and optionally contains a linker that forms two or more ionic bonds between the reactive moieties.

The reactive moieties, upon reaction with thiol groups on the hair follicle, form bonds that are stable.

The binding composition comprises a bismaleate, 2,2'-(ethane-1,2-diylbis (oxy))bis(ethan-1-amine) di-maleate that is supplied as a dry powder to be used at a concentration of 300mg in 10g of water or treatment composition.

It is suggested that the binding agent covalently binds at least two thiol groups in the hair and prevents reversion of the repaired bonds to their free thiol state.

4. Composition and process for permanent shaping of human hair
US Patent 9,554,980
Application No 13/993,500
Granted 31 January 2017
Assignee Kao Germany

Permanent shaping of hair is carried out according to a two-step process.

In the first step, the reductive splitting of the cysteine disulfide bonds is achieved by a reducing agent, and in the second step, neutralisation is carried out by application of an oxidising agent, whereby the cysteine disulfide bonds are restored in the new shape.

In general terms hair is shampooed then shaped using curlers then the reducing composition is applied.

The reducing composition according to the patent consists of 10.5-12.5% w/w ammonium thioglycolate and polyquaternium-86 at a concentration of 0.2-0.5% w/w. It has a pH of 8-9.5.

After a processing time of 1-30 minutes at a temperature of 20-45°C it is rinsed from the hair prior to application of the oxidising composition.

The oxidising composition is pH 3- 5 and comprises hydrogen peroxide at a concentration of 0.5-10% by weight.

The oxidising agent is applied at a temperature range of 20-45°C and rinsed from hair after about eight minutes and the curlers removed.

The patent also describes intermediate steps involving the optional application of a solution of an inorganic salt and polyquaternium-86 prior to application of the reducing composition and again, before the application of the oxidising solution.

Application of these solutions is claimed to significantly improve results.

The patent describes many additional ingredients that may be added to improve efficacy, aesthetics and shelf life.

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