| 摘要 |
<p>A turntable (1) comprises an annular substrate (2) and raised portions (6,7) for retaining a disk-shaped recording medium. The disk-shaped substrate (2) is shaped from a thermoplastic composite resin having a dynamic shear modulus, G', of at least 1.5 x 10<1><0> dyne/cm<2>, a G1' (-40 DEG C)/G2' (100 DEG C) ratio of up to 1.5, and a density of up to 2.0 g/cm<3>, and the receiving portion (6,7) is usually an annulus at the inner and outer edge of the substrate (2), formed on the top of the substrate (2) from a thermoplastic elastomer having a hardness of 5 to 40. A suitable composite resin is a blend of a non-crystalline polycarbonate, polysulfone or polyether with 22-50 vol% of reinforcing fibers, e.g. of glass; suitable elastomers are copolymers of polystyrene, polyolefins or polyesters or mixtures thereof with rubber.</p> |
