Optical lens
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsNoriyuki Kato, Toshiaki Yamada, Eiji Koshiishi, Shu Yoshida
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AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsNoriyuki Kato, Toshiaki Yamada, Eiji Koshiishi, Shu Yoshida
Estimating the term…
An optical lens which can be produced by injection molding on an industrial scale, and which has a high refractive index, a low Abbe's number, a low birefringence index, a high transparency and a high glass transition temperature. The optical lens can be produced by injection molding of a polycarbonate resin (preferably having a reduced viscosity of 0.2 dl/g or higher and a glass transition temperature of 120 to 160° C.), wherein the polycarbonate resin is produced by reacting a diol component comprising 99 to 51 mol % of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and 1 to 49 mol % of bisphenol A with a carbonate diester. It becomes possible to produce an optical lens preferably having a refractive index of 1.60 to 1.65, an Abbe's number of 30 or smaller, a birefringence index of 300 nm or lower and an all light transmittance of 85.0% or higher.
An optical lens composed of a polycarbonate resin which consists essentially of 99 to 80 mol % of a constituent unit derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene represented by the following formula (1):
Dependencies are inferred from the claim text.