Method for manufacturing an optical disc including a single layered disc and a four layered adhesive sheet member for use therein as well as a rolled member thereof

A method of manufacturing an optical disc comprising the steps of:

• forming a four-layer adhesive sheet member by providing an elongated first release paper formed of a polyethylene terephthalate resin which is processed to have a silicone layer, temporarily attaching a plurality of circular protective sheets formed of a polycarbonate resin to the first release paper at fixed longitudinal intervals, forming an adhesive layer of an acrylic adhesive on the protective sheets and temporarily attaching a second release paper of a polyethylene terephthalate resin which is processed to have a silicone layer to the adhesive layer;
• forming a plurality of holes in the adhesive sheet member adjacent each protective sheet such that each hole penetrates all four layers of the adhesive sheet member;
• winding the adhesive sheet member around a mandrel cylinder utilizing a non-adhesive paper interposed between the first and second release papers;
• feeding the adhesive sheet member from the mandrel cylinder;
• thereafter releasing the second release paper from the adhesive sheet member to expose the adhesive layer and thereby form a three-layer adhesive sheet;
• pressing the three-layer adhesive sheet against the surface of a single-layer disc with a roller to transfer and bond the protective sheet on the surface of the single-layer disc through the adhesive layer;
• thereafter releasing the first release paper from the protective sheet bonded to the single-layer disc to expose the protective sheet;
• and
• thereafter placing the single-layer disc in a pressure enclosure and pressurizing same to remove air bubbles.