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US 7,067,609 B2Granted
Polycarbonate resin for optical disk substrate and optical disk substrate
AssigneeIdemitsu Kosan Co., Ltd.
InventorsTatsuya Tomioka, Hiroshi Kawato, Munehiro Chosa
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Abstract
The present invention relates to a polycarbonate resin that has a viscosity average molecular weight of from 10,000 to 17,000 and has characteristic features in an iron content, a free total phenol content, a content of a releasing agent, a fraction of hydroxyl end groups, a 1H-NMR spectrum or the like. The polycarbonate resin has less defects due to flash without increase of an addition amount of a releasing agent to an unnecessary level and therefore is suitable for a material of an optical disk substrate.
Claims8
A polycarbonate resin composition, comprising:
- a polycarbonate resin;
- and
- 150 to 350 ppm of a fatty acid monoester of glycerin;
- wherein said polycarbonate resin composition has a viscosity average molecular weight of from 10,000 to 17,000, an iron content of 0.2 ppm or less and a fraction of hydroxyl end groups of less than 7% by mole.
1 more element
Dependencies are inferred from the claim text.