RECORDING MEDIUM FOR HIGH DENSITY INFORMATION SIGNAL

摘要

PURPOSE:To prevent generation of a blister by forming a recording medium of a blank material contg. a thermoplastic resin refined from a crude thermoplastic resin which is suspension-polymerized by using a specific compd. as well as a conductive material. CONSTITUTION:A titled medium is formed of a blank material contg. a thermoplastic resin refined from a crude thermoplastic resin which is suspension-polymerized by using sodium polyacrylate as well as a conductive material. The sodium polyacrylate having a degree of polymn. ranging to 5,000-100,000 is suitable. The preferred amt. of use if the sodium polyacrylate having 50,000 degree of polymn. is used is 0.005-0.05wt% by the weight of a monomer in the case of a vinyl chloride homopolymer and 0.01-0.1wt% in the case of copolymer. If the sodium polyacrylate is used, the amt. of the water soluble high polymer compd. to be used is decreased and the sodium polyacrylate can be easily removed after the polymn. reaction and therefore the polyvinyl chloride resin contg. extremely less water soluble high polymer compd. is obtd. The disc is free from generation of a blister on the surface.