Process for producing thermoplastic graft copolymer resin containing nitrile

摘要

A process for producing a thermoplastic resin by polymerizing a monomer mixture consisting of an unsaturated nitrile monomer and an alkenyl aromatic hydrocarbon monomer in the presence of a rubbery polymer latex, characterized in that (a) at first, a monomer mixture having an unsaturated nitrile monomer content of 0 to 20 weight % is polymerized in an amount of 30 to 70 weight % based on the amount of the whole monomer mixture, (b) subsequently, the residual monomer mixture having an unsaturated nitrile monomer content of 35 to 90 weight % is polymerized, and the unsaturated nitrile monomer content in the polymer part formed by polymerization in said (a) and (b) steps is 28 to 38 weight %. The thermoplastic resin obtained according to this process has a high chemical resistance, an excellent impact resistance and an excellent processability.