Thermoplastic resin composition of ethylene-propylene-non-conjugated diene terpolymer rubber having improved combined properties of weather resistance and molding appearance

A thermoplastic resin composition comprising 5 to 80 parts by weight of a graft polymer resin (1) obtained by polymerizing 10 to 60% by weight of at least one monomer (b) selected from the group consisting of aromatic vinyl compounds and ethylenically unsaturated compounds of the general formula

• CH.sub.2 .dbd.CRX
• where R is --H or --CH.sub.3, X is --CN or --COOR.sup.1, and R.sup.1 is an alkyl group having 1 to 3 carbon atoms, in the presence of 90 to 40% by weight (on a solid basis) of latex of an ethylene-propylene-non-conjugated diene terpolymer rubber (a) having a gel content of 50 to 95% and a particle diameter of 0.05 to 2 um, the combined amount of (a) and (b) being 100% by weight;
• and 20 to 95 parts by weight of a rigid thermoplastic resin (2), provided that the combined amount of (1) and (2) is 100 parts by weight;
• said graft polymer resin (1) having a degree of grafting of 10 to 100%, and the free polymer resin obtained by extracting said graft polymer resin (1) with acetone has a reduced viscosity (.eta..sub.sp /c) of 0.3 to 1.