OPTICAL INFORMATION RECORDING MEDIUM AND NEAR-INFRARED ABSORBING MATERIAL USED THEREIN

摘要

A phthalocyanine near-infrared absorbing material having a silyl group as a bulky substituent introduced into the benzene ring of the phthalocyanine skeleton, and an optical information recording medium containing the material. This material is excellent in the ability to inhibit association and lightfastness, has a high refractive index in a wavelength region of 770-830 nm, and is highly safe. As a result, an optical information recording medium (a CD-R recording medium) made of this material has a high reflectance and excellent storage and reproduction stabilities. Further this medium has high absorptivity and light reflectivity in a wavelength region of 630-720 nm and is applicable to a pickup using a 630-720 nm semiconductor laser. Thus it can achieve a recording density 1.6-1.7 times as high as that of the current recording medium adapted for use in a wavelength region of 770-830 nm.