| 摘要 |
PURPOSE:To produce a magnetic paint having improved dispersibility, by kneading a nitrile rubber with a kneaded material composed of a polyurethane resin and a ferromagneic metallic iron or its alloy to disperse them in each other. CONSTITUTION:A polyurethane resin is kneaded with the powder of a ferromagnetic metallic iron or its alloy to disperse them in each other. This kneaded material and a nitrile rubber are kneaded to disperse them in each other, thereby obtaining a magnetic paint. Pref. polyurethane resins are those having a softening temp. of 150 deg.C or lower, an average MW of 10,000-200,000 and the degree of polymn. of 200-2,000. Examples of nitrile rubbers are polymers contg. acrylonitrile unit in the molecule and having an average MW of 10,000-150,000 and the degree of polymn. of 100-1000, such as a butadiene/acrylonitrile copolymer and an acrylate ester/acrylonitrile copolymer. |
