| 摘要 |
PURPOSE:To obtain an optical memory disk which decreases change in double refractive indices, simplifiers production process and is less environmentally deteriorated by forming the titled hub of a mixture composed of 7-55wt.% thermoplastic resin and 45-93wt.% magnetic material powder contg. >=80wt.% at least one kind among iron, cobalt and nickel. CONSTITUTION:This hub is formed of the mixture composed of 7-55wt.% thermoplastic resin and 45-93wt.% magnetic material powder contg. >=80wt.% at least one kind among iron, cobalt and nickel. For example, a polyester resin, polyamide resin, polycarbonate resin, polyphenylene oxide resin, etc., are used for the thermoplastic resin. The increase in the double refractive indices of the optical disk memory by adhesion and a change of the environmental conditions is thereby extremely decreased. |
