Microparticles of active ingredient

polymer microparticles encapsulated, containing: a) at least one acrylic copolymer of the HASE type containing: - at least one anionic monomer having a function of polymerizable vinyl and a carboxyl group, - at least one hydrophobic nonionic monomer having a function polymerizable vinyl and - at least one associative oxyalkylated macromonomer having a function polymerizable vinyl and chain hydrophobic hydrocarbon, b) at least one change material solid-liquid phase having a temperature of phase transition ranging from 20 at 90 ° C and c) at least one active substance.