| 摘要 |
PURPOSE:To improve the light resistance of an optical information recording medium, prevent deterioration of its data retrieving efficiency and reduce cost by adding a specific compound to a polymethine coloring matter sewing as a main component of a recording layer. CONSTITUTION:A recording layer consisting mainly of polymethine coloring matter is provided on a base directly or through a primary layer. In addition, a protective layer is provided on the recording layer, if necessary. In a recording medium of the above constitution, a compound expressed in the formula (1) is added. In the formula, R1, R2, R3 and R4 represent hydrogen or -SO2N(R5)2, R5 the alkyl group of upto 8 carbon atoms or hydrogen, and at least one of R1, R2, R3 and R4 -So2N(R5)2.M represents Cu, V, VO2, Pb, Ni, SnCl2, Mn, Zn or Sn. If the compound of the formula is added to the recording layer, it shows a superior preventive effect for improvement of the light resistance and for prevention from data retrieving efficiency of the optical information recording medium. However, the compound can be added to layers other than the recording layer, for instance, the primary layer or protective layer to increase said effect. |
