Abstract: A process for preparing a thermoplastic resin composition capable of giving delustered articles which comprises blending (A) 10 to 30 parts by weight of a graft-copolymer and (B) 90 to 70 parts by weight of a copolymer, the total amount of the components (A) and (B) being 100 parts by weight;said graft-copolymer (A) being prepared by adding a nonionic or cationic polymer coagulant to (1) 70 to 95 parts by weight of diene rubber having a diene content of more than 50% by weight to give a coagulated diene rubber, and then graft-polymerizing (2) 30 to 5 parts by weight of at least one monomer selected from the group consisting a vinyl aromatic monomer, a vinyl cyanide and a methacrylic acid ester onto the coagulated diene rubber, the total amount of the components (1) and (2) being 100 parts by weight; said polymer (B) being prepared by polymerizing at least one monomer selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide, an acrylic acid ester and a methacrylic acid ester.

Abstract: A process for hydrogenating acetylene in hydrogen chloride gas using the catalytic palladium supported on silicon carbide carrier whose iron content is specified to be not more than 1,000 ppm. The catalyst has the advantages of enhancing the conversion of acetylene into ethylene, improving the selectivity of ethylene, and retaining catalytic activity over a long time at a large space velocity. This process can be effectively applied to the hydrogenation of acetylene in hydrogen chloride gas separated from the thermally decomposed products of 1,2-dichloroethane which occurs in the production of vinyl chloride; namely, the hydrogen chloride gas that contains thus hydrogenated acetylene (ethylene) can be recycled in such an effective way that 1,2-dichloroethane can be produced economically.