Patent · US Expired

Polymer packaging material for liquid crystal cell

US4456638A · kind A · utility

10Cited by
13References
12Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 1, 1983
Grant dateJun 26, 1984
Priority date
Expiry dateNov 1, 2003

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC09K2323/02
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A twisted nematic liquid crystal material is sandwiched between two electrode carrying polymer film or sheet substrates in a liquid crystal display assembly. The substrate material preferably is a semi-crystalline aromatic heterochain polymer characterized by a glass transition point (T.sub.g) of at least 90.degree. C. and devoid of secondary transitions in the -50.degree. C. to +80.degree. C. range. The crystallinity of the polymer material is controlled so that the crystallite size in the polymer material is substantially smaller than the wave length of visible light (350-750 micrometers). In a preferred embodiment, an optically isotropic top substrate is formed by a sheet of amorphous cast thermosetting acrylic resin and the lower substrate is formed by a flexible sheet of semi-crystalline aromatic heterochain polymer.

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