| 摘要 |
PROBLEM TO BE SOLVED: To deal with a DVD system by incorporating first and second dye materials respectively having absorption peaks at specific wavelengths in a recording layer to shorten an interval and a length of a track pitch in a predetermined wavelength range, thereby improving a recording density. SOLUTION: A recording layer contains a first dye material having a sub- absorption peak in 600 to 700 nm and a second dye material having a maximum absorption peak in 400 to 600 nm. As the first material, a phthalocyanine dye represented by a formula I is preferably, and as the second material, a porphyrin dye represented by a formula II is preferable. In the formula I, (R1 to R8 are each a hydrogen, or a monovalent organic residue, M is two hydrogens or bivalent to tetravalent metal, and X1 , X2 are each a halogen or the like. In the formula II, R9 to R16 are each a halogen, a hydrogen or the like, A1 to A4 are each N or CR17 R17 is a hydrogen or the like, M is two hydrogens or metal, and X3 , X4 are each a halogen or the like. Thus, information can be recorded in a DVD system having a laser beam including a wavelength of 600 to 680 nm as a recording light. |
