Patent ID: 7803461

Claim:
A silicone-acrylic impact modifier having multi-layer structure, which is characterized by containing 1-40 weight % of a silicone rubber seed containing one or more vinyl copolymers; 20-80 weight % of an acrylic rubber core covering the silicone rubber seed; and 19-40 weight % of a shell containing one or more vinyl copolymers and covering the acrylic rubber core, wherein the silicone rubber seed is characterized by containing i) 0.1-10 weight % of one or more vinyl copolymers; ii) 50-94.9 weight % of a silicone rubber layer covering the vinyl copolymers; and iii) 5-40 weight % of an alkyl methacrylate monomer covering the silicone rubber layer wherein the vinyl copolymer of i) is one or more compounds having a glass transition temperature of at least room temperature and selected from the group consisting of an aromatic vinyl monomer of styrene, α-methyl styrene, p-methyl styrene, p-butyl styrene and 3,4-dichloro styrene; an alkyl acrylate of ethyl acrylate; an alkyl methacrylate of methyl methacrylate and glycidyl methacrylate; benzyl methacrylate; and a cyano vinyl monomer such as acrylonitrile and methacrylonitrile.