| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk substrate having a high light transmittance, little haze, low water absorption and a low index of double refraction. SOLUTION: The optical disk substrate consists of an alicyclic polyolefin obtained by hydrogenating an aromatic polyolefin in the presence of a hydrogenation catalyst and satisfying the following conditions (1)-(4); (1) the rate of hydrogenation of aromatic rings is 90-99.5%, (2) the alicyclic polyolefin does not show a peak and does not substantially show a signal in the range of 6.3-6.8 ppm in its IH-NMR spectrum measured in heavy chloroform at room temperature, (3) the reduction viscosity (in toluene, 0.5g/dl, 30 deg.C) is >=0.2 and (4) the thermal deformation temperature is >=80 deg.C. |
