Pioneer Electronic Corporation

Pioneer Video Corporation

Masahide Itoigawa

Haruhisa Maruyama

Shinichi Hanzawa

Masaaki Motokawa

Yoshitaka Nonaka

Junichi Watanabe

Yoshikazu Hirai

Mitsuhiko Sasano

An optical disc has a pair of light-transmissible circular substrates each having an inner non-data region disposed around a center hole thereof, a data region disposed around the inter non-data region for bearing signals corresponding to information to be recorded and an outer non-data region disposed around the data region which are formed on a major surface of the substrate. The optical disc has a reflective layer formed on the data region and a protective layer made of an ultraviolet ray setting resin containing metal ions formed on the reflective layer. The optical disc has an adhesive layer made of an adhesive composition containing an ultraviolet ray setting component and an anaerobic hardening component disposed between the protective layers of the circular substrates for adhering the circular substrates.

Optical disc and method for manufacturing the same

A laminate optical disc which has excellent heat resistance and also has sufficient bond strength. Radiation-curing adhesive layers are formed on a pair of transparent base plates excluding the outermost circumferential portions, respectively, and an ultraviolet-curing resin is applied to the outermost circumferential portion. Then, the pair of transparent base plates are bonded together by the radiation-curing adhesive layers, and also ultraviolet light is irradiated to the ultraviolet-curing resin to fix the base plates firmly to each other along the outermost circumferential portions. In a process for producing a laminate optical disc, radiation-curing adhesive layers are formed respectively on a pair of transparent base plates, and then irradiated with a radiation excluding at least the outermost circumferential portion to be tackified. After the thus treated base plates are bonded together by the radiation-curing adhesive layers, the outermost circumferential portions of these layers are irradiated until they lose tackiness.

Process of reproducing optical discs and optical discs produced by the

Growing community of inventors

Yamanashi, Japan

Masahide Itoigawa