Patent ID: 6488898
Filing Date: 2002-12-03
Classification: C08F

Abstract:
A process for preparing acrylonitrile-styrene copolymer by a continuous bulk or solution polymerization, the process comprising the steps of:(a) separately feeding 70 to 90 part by volume and 10 to 30 part by volume based on the total input of a raw material monomer into first and second reactors from a raw material monomer storing section via two feeding sections, the raw material monomer consisting of 50 to 90 part by weight of styrene, 10 to 50 part by weight of acrylonitrile, 0 to 30 part by weight of polymerization solvent, and 0 to 0.5 part by weight of chain transfer agent, wherein an output is issued from the second reactor as much as the input at the same time, (b) polymerizing the mixture of the raw material monomers in each reactor for 1.5 to 2.5 hours at a reaction temperature of 130 to 160Â° C. and under the pressure of 1.5 to 4 kg/cm2 G to have conversion ratio of 80%; and (c) recycling part of the reaction solution from the first reactor to a separate mixer, mixing discharged solution from the second reactor and part of monomers directly supplied from one feeding section, and recycling the mixture to the first reactor.