CATIONIC TYPE ULTRAVIOLET RAY HARDENABLE COMPOSITION, LAMINATING METHOD USING SAME, OPTICAL DISK AND MANUFACTURE OF OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To efficiently manufacture an optical disk showing decreased warpage. SOLUTION: A method of manufacturing an optical disk is provided with a process of coating the recording layer side of at least one of two disk substrates each having a recording layer with a cationic type ultraviolet ray hardenable composition showing viscosity of 200 to 1,000 mPa.s measured with a BM type viscometer and an increase ratio of complex viscosity 3 minutes after the start of irradiation of an ultraviolet ray of not more than 300%, while composition being irradiated with ultraviolet ray during dropping down from a nozzle, a process of laminating one disk on the other disk so that the recording layers face each other and a process of extending the cationic type ultraviolet ray hardenable composition by pressing or self weight.