Transparent colored cosmetic ingredient for cosmetic products, possibly capable of automatically changing color when irradiated by ultraviolet light
A cosmetic ingredient for cosmetic products has a polymer structure which includes an emollient or film-forming cosmetic polymer which is transparent to light. An organic chromophore molecule is inserted and chemically linked into the polymer, which can be a fixed color molecule or a photochromic molecule capable of rapidly switching from one color to another. The colored or photochromic molecule is inserted and chemically linked by transesterification into a cosmetic oil provided with functionalities which are suitable for the chemical anchoring of the molecule and chemically linked to said oil. The cosmetic oil may be a silicone macrodiol functionalized with a photochromic derivative designed so as to ensure the transition between a colorless state and a colored state following irradiation with ultraviolet light.
1 . A cosmetic ingredient with polymer structure for cosmetic products, wherein said polymer structure includes a cosmetic polymer with an emollient function or with a film-forming function, transparent to light both in dry and solution condition, with an organic photochromic molecule chemically linked in a covalent manner inside said polymer, wherein said photochromic molecule has a chemical structure of the spiropyran type, capable of rapidly switching from one color to another, wherein said photochromic molecule has the following structure FC-C3-Et:
2 . The cosmetic ingredient according to claim 1 , wherein that said polymer with an emollient function is made of polysiloxane.
3 . The cosmetic ingredient according to claim 2 , wherein that said polysiloxane is bis-hydroxyethoxypropyl dimeticone.
4 . The cosmetic ingredient according to claim 1 , wherein that said polymer with a cosmetic film-forming function is made of polyurethane.