07.01.15
US Patent No. 8,999,308 B2; Coty Germany has patented a base and a top coat in which the anhydrous base coat composition consists of a water absorbent compound which is a cosmetically acceptable salt of acrylic or polyacrylic acid, a CO2 releasing compound which is an inorganic or organic carbonate, or bicarbonate, a solvent for the water absorbent compound and the CO2 releasing compound, a wax, auxiliary substances which do not encompass surfactants and optionally, a second water absorbent compound selected from the group consisting of cellulose gum, polysaccharides, natural gums, clays, aluminum silicate, bentonite, aluminum starch octenylsuccinate, acrylic acid and polyacrylic acid. The solvent is dimethiconol in cyclomethicone silicone oil and does not allow an interaction of the salt of acrylic or polyacrylic acid and CO2 releasing compound before the topcoat is applied to the base coat composition. The salt of acrylic or polyacrylic acid and the CO2 releasing compound are present in an amount effective to interact and generate CO2 when the top coat is applied, wherein the amount of the salt of acrylic or polyacrylic acid is 15-35% by weight and the amount of the CO2 releasing compound is 10-80% by weight, the weight percentage being based on the total weight of the base coat composition. The topcoat consists of a film former and water with a viscosity that is lower than that of the base coat composition and the film former is present in the topcoat in an amount effective to form a film on the hair fibers and to be expanded by CO2 after application to the base coat composition.