Patent ID: 6187862
Filing Date: 2001-02-13
Classification: C08F,C08L

Abstract:
A thermoplastic molding composition comprising a grafted rubber and a copolymeric matrix wherein grafted rubber includes a substrate, a first grafted phase and a subsequent grafted phase which are sequentially grafted to said substrate, wherein substrate contains a crosslinked elastomer selected from the group consisting of polyalkyl acrylate and hydrogenated polydiene, and said first grafted phase contains a copolymer consisting of at least one vinylaromatic monomer and at least one member selected from the group consisting of (meth)acrylonitrile and alkyl (meth)acrylate, said vinylaromatic monomer and said member relating by weight as 90/10 to 80/20 and where said subsequent grafted phase contains a copolymer of about 70 to 75 percent relative to the weight of said subsequent grafted phase of at least one vinylaromatic monomer, and about 25 to 30 percent relative to the weight of said subsequent grafted phase of at least one member selected from a second group consisting of (meth)acrylonitrile and alkyl(meth)-acrylate, and wherein weight ratio of said first grafted phase to said subsequent grafted phase is 1/4 to 4/1, said grafted rubber is present in particulate form having a weight average particle size of about 0.1 to 1.0 microns, and wherein matrix contains the polymerized product of at least one vinylaromatic monomer and at least one monomer selected from the group consisting of (meth)acrylonitrile and alkyl(meth)acrylate, said first grafted phase and said subsequent grafted phase being chemically different one from the other.