Teijin Chemicals Limited

Sony Corporation

Koji Ishihata

Nobuyuki Arakawa

Makoto Takagi

Tetsushi Ono

Hisanaga Shimizu

A disc-shaped recording medium having transcription characteristics for fine signals simultaneously with resonance characteristics and stiffness which are characteristics contrary to the transcription characteristics. At least a recording layer and a light transmitting layer are sequentially formed on a substrate and light is illuminated from a light transmitting layer side to record and/or reproduce information signals. The substrate includes a core layer formed of a resin composition comprised of a mixture of two or more resin sorts. The resin composition has tan&#x3b4;, as an index indicating the internal loss, equal to not less than 0.015 as a system in its entirety. The resin composition constituting the core layer is a compounded resin of the incompatible system and is of an islands-sea structure.

Optical recording medium

A resin composition comprising 100 parts by weight of a resin component selected from (a) an aromatic polycarbonate resin (A-1 component) obtained by melt polymerization and, when measured for fluorescent spectrum at an exciting wavelength of 320 nm, having a relative fluorescence intensity of 4&times;10 or less at 465 nm relative to a standard substance, (b) a resin mixture of said A-1 component and a styrene-based resin (A-2 component), and (c) a resin mixture of said A-1 component and an aromatic polyester resin (A-3 component), and 5 to 200 parts by weight of a reinforcing filler. This resin composition gives a molded article superior in wet heat fatigue and various physical properties.

Growing community of inventors

Ehime, Japan

Koji Ishihata