Dai-ichi Kogyo Seiyaku Co., Ltd.

Dai-ichi Ceramo Co., Limited

Del-ichi Ceramo Co., Limited

Norimasa Uesugi

Akira Taniuchi

Hiromitsu Kinoshita

Kazuyuki Hagino

Takamitsu Ohtani

Katuyoshi Saitoh

Hirokazu Kato

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.

Injection compacting composition for preparing sintered body of metal

An injection compacting composition having excellent injection compacting characteristics such as powder flowability and an excellent binder removability and being capable of providing compacts having a high strength and sintered compacts having no defects such as warpage and cracks in high yields, which comprises (1) an inorganic powder and (2) an organic binder comprising a composite acrylic polymer and a wax having a melting point of at most 100.degree. C. and being compatible with said composite acrylic polymer, 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.

Injection compacting composition for preparing sintered bodies

A process for preparing an organic binder which is suitable for use in the preparation of a sintered body of an inorganic powder such as a metallic powder or a ceramic powder, and which is superior in compactibility of the inorganic powder, removability from compacts of the inorganic powder prior to sintering, and yield and quality of sintered body, the process comprising the steps of dissolving (a) an ethylene-vinyl acetate copolymer and/or an ethylene-ethyl acrylate copolymer in (b) an acrylic or methacrylic acid ester or a mixture thereof with a styrene compound, dispersing the resulting solution in an aqueous medium containing a dispersing agent, and carrying out a suspension polymerization in the presence of a polymerization initiator such as an oil-soluble initiator.

Process for preparing organic binder

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Kyoto, Japan

Norimasa Uesugi