PURPOSE: To obtain a DRAW-type optical disc having long-term stability high reflection factor and high absorptive wavelength band by forming an organic color recording layer containing specific pentamethinecyanine and a reflective layer sequentially on a transparent substrate.
CONSTITUTION: Pentamethinecyanine expressed by formula I (R is an alkyl group; W is hydrogen, an aryl group, an aromatic group and halogen; and X is iodine) is dissolved in diacetone alcohol. This solution of the dissolved pentamethinecyanine is applied to the surface of a transparent substrate such as polycarbonate or polymethylmethacrylate using a spin coating technique, then the applied coat is dried to form an organic color recording layer. After that, a reflective layer for laser beam reflection is formed on the organic color recording layer using a sputtering technique with a laser beam, thus to obtain a DRAW-type optical disc. The typical material for the formation of the reflective layer is Al, Au, Cu or Ag. The obtained DRAW-type optical disc has a long stable C/N ratio and high sensitivity.
YANAGISAWA SHUICHI
HAYAMIZU MASAAKI
OKAZAKI YASUKI
NIPPON KANKO SHIKISO KENKYUSHO
Next Patent: DRAW-TYPE OPTICAL DISC CORRESPONDING TO COMPACT DISC OR COMPACT DISC-ROM