Polycarbonates for optical use, and their applications
AssigneeGeneral Electric Company
InventorsKazushige Inoue, Tomoaki Shimoda
Life of this patent
Estimating the term…
Abstract
This specification discloses polycarbonates for optical use. These polycarbonates are prepared by reacting a bisphenol and carbonic diester in the presence of an alkaline compound catalyst. These polycarbonates have: (i) an intrinsic viscosity (IV) as determined at 20° C. in methylene chloride of between 0.34 and 0.38; (ii) a glass transition temperature (Tg) as determined by DSC of between 143 and 147° C.; and (iii) an intrinsic viscosity (IV) and glass transition temperature (Tg) ratio complying with the following general formula (A): IV×95.888+107.9<Tg<IV×95.888+113.7 (A)
Claims10
Polycarbonates for optical use, prepared by melt polycondensing a bisphenol and carbonic diester in the presence of an alkaline compound catalyst, wherein said polycarbonates have:
- (i) an intrinsic viscosity (IV) as determined at 20° C. in methylene chloride of between 0.34 and 0.38;
- (ii) a glass transition temperature (Tg) as determined by DSC of between 143 and 147° C.;
- and
- (iii) an intrinsic viscosity (IV) and glass transition temperature (Tg) ratio complying with the following formula (A):
- IV×95.888+107.9<Tg<IV×95.888+113.7 (A).
Polycarbonates for optical use, prepared by melt polycondensing a bisphenol and carbonic diester in the presence of an alkaline compound catalyst, wherein said polycarbonates have:
- (i) an intrinsic viscosity (IV) as determined at 20° C. in methylene chloride of between 0.34 and 0.38;
- (ii) a glass transition temperature (Tg) as determined by DSC of between 143 and 147° C.;
- and
- (iii) an intrinsic viscosity (IV) and glass transition temperature (Tg) ratio complying with the following formula (A):
- IV×95.888+109.3<Tg<IV<95.888+112.3 (A).
Dependencies are inferred from the claim text.