| 摘要 |
A latex of a highly crosslinked butadiene rubber polymer comprising not less than 50% of butadiene, 1.0 to 10% of a crosslinking agent and a remainder of an ethylenically unsaturated monomer copolymerizable with butadiene, and having a particle size of 600 to 3,000 ANGSTROM and a degree of swelling of not greater than 7 is obtained by one or more stages of emulsion polymerization. By polymerizing 15 to 30 parts of a monomer mixture of an alkyl methacrylate, an aromatic vinyl monomer, and optionally a crosslinking agent and an unsaturated nitrile in the presence of 85 to 70 parts of the rubber polymer, a graft copolymer is obtained. A composition comprising 2 to 40% of this graft copolymer and 98 to 60% of a vinyl chloride resin possesses high impact resistance coupled with improved stress-whitening resistance, which properties cannot be easily obtained at the same time in conventional resin compositions. |
