| abstract |
(57) [Summary] [PROBLEMS] To be useful for direct bonding of an optical disk substrate, Provided an adhesive composition that can suppress the corrosion of metal films, especially aluminum films, in the durability test of product optical discs under high temperature and high humidity conditions, and also suppressed the corrosion of metal films under high temperature and high humidity. Provide an optical disk. An adhesive composition comprising (1) a urethane acrylate having polytetramethylene glycol as a skeleton, (2) an acrylate having a hydroxyl group in a molecule, and (3) a photopolymerization initiator, An adhesive composition containing 40% by weight or more of the urethane acrylate (1) based on the total weight of the urethane acrylate (1) and the acrylate (2) is used. |