| 摘要 |
PROBLEM TO BE SOLVED: To completely harden a protective coat film of an optical disk even when the film is thin and to prevent warpage of the film even when the film is thick. SOLUTION: The resin material used for the protective coat film is a cation polymerization type epoxy UV-curing resin instead of a radical polymerization type UV-curing resin conventionally used. This prevents the conventional problem that a film does not harden when the film is thin. Since the obtained film has small shrinkage by hardening, warpage of the disk can be also decreased. |
