| 摘要 |
PURPOSE:To prevent the distortion of a substrate by constituting a hub of an inner peripheral part and an outer peripheral part, forming the inner peripheral part with the 7-55wt.% of thermoplastic resin and the 45-93wt.% of magnetic substance powder and/or magnetic substance fiber and forming the outer peripheral part with transparent resin. CONSTITUTION:The hub is composed of an inner peripheral part 1 and an outer peripheral part 2 to surround this part 1. Then, the inner peripheral part 1 is composed of the 7-55wt.% of the thermoplastic resin and the 45-93wt.% of the magnetic substance powder and/or the magnetic substance fiber and the external peripheral part 2 is composed of the transparent resin. When the hub is irradiated with ultraviolet ray 7 and is bonded, a surface side where the hub is attached is irradiated by the ultraviolet rays 7 and the ultraviolet ray 7 to pass through the outer peripheral part 2 is reflected and arrives at an adhesive agent layer. As the transparent resin to constitute the outer periph ery 2, polyester resin, polycarbonate resin and impact resistance polystyrene resin, etc., can be used. Thus, the distortion of an optical disk substrate 4 can be prevented. |
