| abstract |
A hydrogenated aromatic vinyl polymer in which the degree of hydrogenation of the aromatic rings is 97 % or higher, the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), (Mw/Mn), is 2.0 or lower, the weight-average molecular weight (Mw) is 100,000 to 300,000, and the content of components having a molecular weight (M) of 10,000 or lower is 2 wt.% or lower based on the whole polymer; a hydrogenated aromatic vinyl polymer in which the number of foreign particles having a particle diameter of 0.5 νm or larger is 3.0x104 or smaller per g of the polymer; a substrate for information-recording media which is obtained by molding a resin material comprising a hydrogenated aromatic vinyl polymer in which the degree of hydrogenation of the aromatic rings is 97 % or higher, the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), (Mw/Mn), is 2.0 or lower, and the weight-average molecular weight (Mw) is 100,000 to 300,000; and a process for producing the substrate. |