| 摘要 |
PURPOSE: To obtain an optical recording medium having excellent recording characteristics by using urethane resin in which the weight ratio of a side chain part to a main chain part falls within a specific range as a shape memory resin in the medium having a recording layer made of the resin on a board. CONSTITUTION: In an optical recording medium such as an optical disk, etc., in which shape memory resin for recording or recording and erasing information is used as a recording layer, as the resin, urethane resin in which the weight ratio of a side chain part to a main chain part is 1/99 to 50/50 is used. As the urethane resin, polyol having side chain is used, and the side chain part of the urethane resin uses alkyl group or aryl group. The urethane resin is preferably obtained by reacting diisocyanate, polymer diol having a molecular weight of 500 to 10000 and side chain of alkyl group or aryl group and low molecular weight diol having a molecular weight of 20 to 500. |
