Injection compacting composition for preparing sintered body of metal powder and sintered body prepared therefrom

摘要

An injection compacting composition suitable for preparing sintered bodies of metal powders, which can provide, by injection compacting, compacts having a high strength from which the binder can be removed without causing deformation, cracking and other defects, thus providing sintered metallic materials having a high density and no defects such as warpage and cracks in high yields, which comprises (1) a metal powder and (2) an organic binder comprising a composite acrylic polymer and an atactic polypropylene, said composite acrylic polymer being a suspension polymerization product prepared by dissolving (a) a polymer selected from the group consisting of an ethylene-vinyl acetate copolymer and an ethylene-ethyl acrylate copolymer in (b) an acrylic or methacrylic acid ester monomer or a mixture of an acrylic or methacrylic acid ester monomer and a styrene compound monomer, dispersing the resulting solution in an aqueous medium in the presence of a dispersing agent, and subjecting the resulting dispersion to a suspension polymerization.