| 摘要 |
PROBLEM TO BE SOLVED: To perform a high density recording and a reproduction of information when recording light of 630-640 nm wavelength is used by using a cyanin based coloring matter which is represented by a specified formula as the recording layer of a write-once type optical recording medium. SOLUTION: On the recording layer of a write-once type optical recording medium, a cyanin based coloring matter which is represented by the formula is used. In the formula, for R1 -R6 , an alkyl group of which the number of carbon atoms is 1-16, preferably, an alkyl group of which the number of carbon atoms is 1-4 is used, and for X, a halogen ion or a halogen compound ion, e.g. ClO4 , I, Br, PF6 and BF4 is used. Also ϕ and ψ are a benzene ring or a naphthalene ring, or a benzene ring or a naphthalene ring having a substituent group. Such a cyanin base coloring matter has a light absorbing zone at a wavelength of 630-640 nm, and also, is prepared in a manner to sublimate or evaporate at a temperature which is lower than the thermal decomposition temperature, and after the cyanin based coloring matter sublimates by the radiation of recording light, the recording of information is performed through the change of optical characteristics by coagulation. |
