Kenryo Namba

Reversible Read-Write-Erase Properties of Styrene Oligomer Optical Recording Media

Optical recording media consisting of a thermoplastic oligomer resin blended with a photoabsorbing pigment permit heat-mode pit writing without corona discharge, as well as heat erasure and rewriting. The properties of recording layers consisting of styrene oligomers having number-average molecular weights (Mn) of 400 or 3000 blended with copper phthalocyanine or anthraquinone pigment, when subjected to recording and playback operations with a helium-neon (He–Ne) laser, are investigated. In addition, full-surface heat erasure, and scanning heat erasure are discussed. Pits with an outside diameter of 2.5 µm were recorded (writing time, 2 µsec) with a 10 mW He–Ne laser light. A readout signal contrast (ratio of reflected light intensity in the absence of pits to that in the presence of pits) of 3 was obtained.

Metal Complex Dyes

Many kinds of metal complexes have been synthesized for the chemical analysis of metal ions and for use as catalysts for organic reactions, as dyes and pigments, and in other materials. Many metal complexes are also used as mordant dyes. They are, in general, insoluble or slightly soluble in water and most organic solvents. Some kinds of nickel complexes have been used for the Q-switch dye laser,1 in infrared absorbing films for agricultural uses, and as infrared absorbers in sunglasses and goggles, antioxidants for polymers,2,3 and singlet oxygen quenchers for the photofading of dyes.4