| 摘要 |
PURPOSE:To enhance the weatherability of an optical recording medium, by a method wherein a recording layer consists of cyanine dye and polybutyl metacrylate. CONSTITUTION:Cyanine dye used for a recording layer is so constructed that nitrogen-containing heterocycles are combined with the both ends of a methine chain, as shown by a formula I (wherein (n) represents the natural number of methine chains, R and X<-> respectively represent an alkyl group and an anion such as Cl<->, Br<->, I<->, and ClO4<->). On the other hand, polybutyl, metacrylate is shown by formulas II (poly-tert-butyl metacrylate) and III (poly-iso-butyl metacrylate). The composition ratio of the aforesaid cyanine dye and polybutyl metacrylate is in the range of 25/75<A<75/25 (cyanine dye/polybutyl metacrylate=A). The aforesaid cyanine dye and polybutyl metacrylate are dissolved in a solvent to meet the aforesaid composition, thereafter being coated to a transparent substrate to form a recording layer. As the substrate, a rigid transparent substrate of plastic etc. for a normal optical disk is preferable. As the solvent, a general-purpose solvent of every sort such as methanol and ethanol and a mixed solvent of these are used. |
