PURPOSE: To produce a rubber-modified styrene/acrylonitrile copolymer resin improved in impact resistance and gloss by copolymerizing a styrene monomer with an acrylonitrile monomer in the presence of a rubbery polymer and a solvent in a perfect mixing type reactor under specified conditions.
CONSTITUTION: 3-20 pts.wt. rubbery polymer, 0-70 pts.wt. solvent, 65-92 pts.wt. styrene monomer, 35-8 pts.wt. acrylonitrile monomer and at least 30ppm radical polymerization initiator are fed into a perfect mixing type reactor and subjected to a batchwise polymerization reaction at 80-150°C under agitation until the reaction mixture reaches an inverted-phase state in which the rubbery polymer is dispersed in the form of particles. After being cooled to 70°C or below, the reaction solution is mixed with 1-10 pts.wt. polar solvent while it is continuously discharged from the reactor. The resulting mixture is then introduced into a plug flow type reactor and subjected to a continuous copolymerization reaction to a conversion of 60-100%.
TANAKA HIROSHIGE
NANBU HIDESABURO
NOZAWA MASAYUKI
