Molding material for plastic lens
AssigneeNippon Zeon Co., Ltd.
InventorsTeruhiko Suzuki, Tsutomu Nagamune
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Abstract
A molding material for plastic lenses, comprising a hydrogenated product of an aromatic vinyl polymer, wherein the hydrogenated product of the aromatic vinyl polymer has properties that the hydrogenation rate of aromatic rings is at least 97%, the weight average molecular weight (Mw) is within a range of 50,000 to 500,000, and the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is at most 2.5, a plastic lens obtained by molding the molding material, novel hydrogenated products of aromatic vinyl polymers, which are suitable for use as molding materials, and a production process thereof.
Claims4
A process for producing a hydrogenated product of an aromatic vinyl polymer by hydrogenating an aromatic vinyl polymer obtained by polymerizing an aromatic vinyl compound, the process comprising
- polymerizing the aromatic vinyl compound to synthesize an aromatic vinyl polymer having a weight average molecular weight (Mw) within a range of 100,000 to 400,000 and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of at most 2.0, and
- then subjecting the aromatic vinyl polymer to a hydrogenation reaction in the presence of a hydrogenation catalyst supported on a silica-alumina carrier to obtain a hydrogenated product having the following properties:
- (a) the hydrogenation rate of aromatic rings being at least 97%;
- (b) the weight average molecular weight (Mw) being within a range of 100,000 to 300,000;
- and
- (c) the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) being at most 2.0.
Dependencies are inferred from the claim text.