| 摘要 |
PURPOSE:To permit ternary recording by 2 kinds of dots by projecting light of controlled exposures to an optical recording medium having a recording layer contg. a polydiacetylene deriv. compd. and specific compd. to discolor the exposed parts, thereby forming the pits consisting of recesses. CONSTITUTION:The light of the exposures controlled according to recording information is projected to the optical recording medium having the recording layer 2 contg. the polydiacetylene deriv. compd. and >=1 kinds of the compd. expressed by the formula [I], [II] or [III] to discolor the exposed parts 3a, 3b of the exposure Q1 and to form the pits consisting of the recesses in the exposed parts of the exposure Q2. (Q1<Q2). In the formulas, R<1> and R<2> denote a hydrogen atom or alkyl group, cyclic alkyl group, allyl group, aralkyl group or aryl group, R<3> and R<4> denote a hydrogen or halogen atom. Z1 and Z2 denote an atomic group necessary for completing a nitrogenous heterocycle and A1 and A2 denote a bivalent hydrocarbon group for forming a 5-membered or 6-membered ring. High-density recording by the ternary recording is thereby permitted with a sheet of the recording medium. |
