Birch Stewart Kolasch & Birch, LLP
Process for preparation of rubber-modified aromatic vinyl resin compositions
 This invention relates to a process for preparing rubber-modified aromatic vinyl resin compositions by polymerizing a raw material solution containing 3 to 20% by weight of rubbery polymer, 50 to 97% by weight of an aromatic vinyl monomer, and 0 to 30% by weight of a solvent until the conversion of said aromatic vinyl monomer falls in the range from 30 to 70%, adding a (meth)acrylate monomer or its mixture with other monomers to the reaction mixture so that the ratio by weight of the aromatic vinyl monomer in the reaction mixture to the (meth)acrylate monomer becomes 85/15 to 50/50, continuing the polymerization, and devolatilizing to remove the unreacted monomers, solvent, and the like. It is possible by this process to prepare easily and economically rubber-modified aromatic vinyl resin compositions of easy processability, good surface properties in respect to appearance and scratch resistance, and good balance between impact resistance and rigidity. 
Nippon Steel Chemical Co., Ltd.
C C C
C08F C08F C08L
inventional inventional inventional
Masanari Yasuji
Fujita Shichijo