Disclosed is an optical material including a cyclic olefin copolymer containing at least a repeating structural unit [A] represented by the general formula (1) and a repeating structural unit [B] represented by the general formula (2) and having a molar ratio [A]/[B] of from 95/5 to 1/99, wherein the absolute value of the ratio ΔOB/ΔF is from 0.001 to 0.250 in which ΔOB represents the amount of a change in the absolute value of the orientation birefringence calculated from the phase difference (nm) at a wavelength of
633
nm/film thickness (μm) in a stretched film obtained from the optical material, and ΔF represents the amount of a change in the absolute value of the orientation coefficient determined from the dichroic ratio of parallel light intensity I
∥
to perpendicular light intensity I
⊥
, each relative to the orientation direction according to Raman spectroscopy.
US9128238B2
申请人:——
公开号:US9128238B2
公开(公告)日:2015-09-08
[EN] METHOD FOR PRODUCING BISPHENOL AND METHOD FOR PRODUCING POLYCARBONATE RESIN<br/>[FR] PROCÉDÉ DE PRODUCTION DE BISPHÉNOL ET PROCÉDÉ DE PRODUCTION DE RÉSINE DE POLYCARBONATE<br/>[JA] ビスフェノールの製造方法、及びポリカーボネート樹脂の製造方法
Cyanation of acetals was achieved by t-butyl isocyanide in the presence of TiCl4, producing cyanohydrin ethers in good yields. β-(Trimethylsilyl)ethyl isocyanide in the combination with TiCl4 effected the cyanation as well.