Patent ID: 7897686

Claim:
A method for preparing a graft rubber latex which is characterized by graft copolymerization of a mixture containing (a) 50 to 70 weight part of rubber latex having a gel content of at least 95% and an average particle diameter of 2,500 to 5,000 Å; (b) 30 to 50 weight part of a monomer mixture composed of one or more compounds selected from the group consisting of an aromatic a vinyl compound, vinyl cyan compound and an acrylate compound; and (c) 1 to 20 weight part of a latex which has an average particle diameter of 20 to 100 nm and, is prepared by emulsion polymerization with one or more compounds selected from the group consisting of an aromatic vinyl compound and a vinyl cyan compound, and has an average particle diameter of 20 to 100 nm, wherein a step of adding a redox polymerization initiator is additionally included when the polymerization conversion rate reaches at least 94%, and wherein the rubber latex of (a) is one or more compounds selected from a group consisting of polybutadiene, butadiene-styrene copolymer, butadiene-alkylacrylate copolymer, polyisoprene and polychloroprene.