| 摘要 |
PURPOSE:To obtain a copolymer having a low content of unreacted monomer and excellent heat resistance, by controlling monomer addition so that the unreacted unsaturated nitrile remains at the completion of monomer addition at a high concentration in the polymerization system and polymerizing the monomers so that the diameter of latex olymer is extremely small, in the production of ABS resin. CONSTITUTION:In emulsion-polymerizing 70-80wt% alpha-alkylstyrene (e.g., alpha- methylstyrene) and 30-20wt% unsaturated nitrile (e.g., acrylonitrile) by use of a radical initiator (e.g., potassium persulfate), monomer addition is controlled so that the unreacted unsaturated nitrile monomer remains at a concentration of 31wt% in the polymerization system at the completion of monomer addition. Further, addition of deionized water and an emulsifier is adjusted so that at least 90% of the polymer particles in the latex at the completion of the polymerization have a diameter <=0.10mu. The copolymer thus obtained has a low thermal decomposition tendency because of lowered content of coagulum and unreacted monomer. |
