OPTICAL RECODING MEDIUM AND PREPARATION THEREOF

摘要

PURPOSE:To provide an inexpensive optical recording medium having a relatively large C/N ratio and long recording life by providing one or more layer composed of thermoplastic polymer fine particles having a specific particle size on a support and setting the refractive index difference between said layer and the circumferential material thereof to 0.03 or more. CONSTITUTION:As a substrate 11, a glass substrate having an inner groove formed thereto is used and a coating composition wherein polystyrene fine particles as thermoplastic polymer fine particles 12 having a particle size of 0.2mum or less and a non-anaerobic photosetting resin as a solvent are well mixed in a wt. ratio of 2:1 is applied to the substrate by a roll coater and irradiated with ultraviolet rays to form a photosetting resin layer 13. In recording, the optical recording medium thus constituted is irradiated with laser beam 22 to melt the thermoplastic polymer fine particles 12 to form a pit 21. The refractive index difference between the thermoplastic polymer fine particles 12 and the circumferential material is set to 0.03 or more. As a result, the optical recording medium layer can be formed by an extremely simple process using the roll coater and an optical disk having a relatively large C/N ratio and forming a recording pit having long life can be obtained.