Patent ID: 7049368
Filing Date: 2006-05-23
Classification: C08F,C08L

Abstract:
1. A method for preparing an acrylonitrile-styrene-acrylate (ASA) type resin comprising a discontinuous elastomeric phase dispersed in a rigid thermoplastic phase, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase and wherein the elastomeric phase comprises a polymer having structural units derived from at least one (C 1 -C 12 )alkyl(meth)acrylate monomer, which comprises the steps of: (a) polymerizing mixture of monomers in a first stage in the presence of the elastomeric phase, at least one of which monomers is selected from the group consisting of vinyl aromatic monomers and at least one of which monomers is selected from the group consisting of monoethylenically unsaturated nitrile monomers, followed by (b) polymerizing a mixture of monomers in at least one subsequent stage in the presence of the elastomeric phase from (a), wherein the monomers comprise at least one vinyl aromatic monomer, at least one monoethylenically unsaturated nitrile monomer, and at least one monomer selected from the group consisting of (C