| 摘要 |
An optical information recording medium composed of a substrate and a recording layer having a dye compound of the formula (I): R<1>R<2>C=L<1>-L<2>=L<3>-NR<3>R<4> in which each of R<1> and R<2> is an electron-attracting group (i.e., electron-withdrawing group) having a Hammett's substituent constant sigma p in the range of 0.2 to 0.9; each of L<1>, L<2>, and L<3> is a methine group which can have a substituent under such condition that two or three of L<1>, L<2>, and L<3> can form a ring structure together with the substituent; and each of R<3> and R<4> is a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, or a heterocyclic group, provided that each set of R<1> and R<2>, R<2> and a substituent of L<1>, R<2> and a substituent of L<2>, R<2> and a substituent of L<3>, a substituent of L<1> and R<3>, a substituent of L<2> and R<3>, a substituent of L<3> and R<3>, and R<3> and R<4> can be connected to each other to form a ring structure, is advantageously employed for recording information utilizing a laser beam having a wavelength of 550 nm or shorter. |
