| 摘要 |
PURPOSE:To prevent the deterioration of a recording film by injection-molding a bisalkane polycarbonate resin contg. a specific phosphite and providing the recording film thereon. CONSTITUTION:The bisalkane polycarbonate resin contg. <=0.005wt% phosphite expressed by the formula and having 130,000-22,000 average mol. wt. is injection-molded and the recording film is formed thereon. R1, R2 in the formula are an alkyl group or aryl group and R3 is a hydrogen atom or compd. consisting of an alkyl group or aryl group. The content of the phosphite is <=0.0025wt% by the weight of the polycarbonate resin. An adverse influence is exerted to the recording film and the deterioration of the film is accelerated if the phosphite is excessively added. The optical disk which has no adverse influence on the recording film, has good double refractions, lessens the decrease of a CN ratio and has excellent quality is thus obtd. |
