Patent · US Expired

Optical film

US6210872A · kind A · utility

8Cited by
3References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 18, 2000
Grant dateApr 3, 2001
Priority date
Expiry dateMay 18, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B5/3016
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

A novel optical film capable of readily vitrifying the tendency and state of liquid crystal alignment, excellent in the ability to retain the alignment state, and suitable for the application to optical elements. The film is produced from a liquid-crystal material containing as the essential ingredient a liquid-crystal polyester having structural units (A) and (B) as the essential unit, exhibiting a vitrified state at a temperature lower than the liquid-crystal transition point, and having a logarithmic viscosity number (.eta.) of 0.04-0.4 dl/g as measured at 30.degree. C. in a phenol/tetrachloroethane solvent (60/40 by weight), wherein each X represents independently O or C.dbd.O; each Y represents independently a group selected from among F, Cl, Br and 1-4C alkyls; and n is 0 or 1. ##STR1##

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.