PURPOSE: To improve recording sensitivity and C/N ratio by incorporating a specific acrylic resin into an underlying layer.
CONSTITUTION: The acrylic resin contg. the atomic group expressed by the formula I as a repeating unit is incorporated into the underlying layer of an optical information recording medium including a polycarbonate substrate, the underlying layer formed on this substrate and a recording layer formed on the underlying layer. In the formula I, R1 denotes a hydrogen atom. or methyl group, R2 denotes an alkyl group of 1W4C. More specifically, a polymethyl methacrylate resin which is a homopolymer resin of methacrylate monomers such as methyl methacrylate, ethyl methacrylate and butyl methacrylate and/or acrylate monomers such as methyl acrylate and ethyl acrylate, respectively or is a copolymer resin copolymerized with ≥two kinds among the above- mentioned monomers is more particularly adequately used. The recording sensitivity and C/N ratio are thereby improved.
TANAKA TOKUJI
OTA SEIICHI
