Optical rotator formed of a twisted nematic liquid crystal polyster including an ortho-substituted aromatic unit

• US 5,206,752 A
• Filed: 05/20/1991
• Issued: 04/27/1993
• Est. Priority Date: 05/18/1990
• Status: Expired due to Term

• Current Assignee: Nippon Mitsubshi Oil Corporation
• Original Assignee: Nippon Oil Corporation (ENEOS Holdings, Inc.)
• Inventors: Itoh, Hiroyuki, Toyooka, Takehiro, Iida, Shigeki
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): GROSS, ANITA P
• Application Number:
  US07/703,179
• Time in Patent Office: 708 Days
• Field of Search: 252/299.01, 428/1, 359/103, 359/106
• US Class Current: 349/183
• CPC Class Codes: C09K 19/126 Compounds containing at least one asymmetric carbon atom
• CPC Class Codes: C09K 19/3809 Polyesters; Polyester derivatives, e.g. polyamides
• CPC Class Codes: C09K 2323/021 Inorganic, e.g. glass or silicon oxide
• CPC Class Codes: C09K 2323/027 Polyimide
• CPC Class Codes: G02B 1/08 made of polarising materials
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02F 1/133636 with twisted orientation, e.g. comprising helically oriented LC-molecules or a plurality of twisted birefringent sublayers
• CPC Class Codes: G02F 1/133637 characterised by the wavelength dispersion

Abstract

An optical rotator comprising a light transmitting base, an alignment film layer formed on said base, and a film layer formed of a liquid crystalline polymer. The film layer exhibits a twisted nematic orientation in the state of liquid crystal and assumes a glassy state at a temperature below a liquid crystal transition point of the polymer. The polymer is a polyester which includes an ortho-substituted aromatic unit.

Claims

1. An optical rotator comprising a light transmitting base;

an alignment film layer formed on said base; and

a film layer formed of a liquid crystalline polyester which includes an ortho-substituted aromatic unit which exhibits twisted nematic orientation in the state of liquid crystal and assumes a glassy state at a temperature below the liquid crystal transition point of the polyester.

2. An optical rotator as set forth in claim 1, wherein said liquid crystalline polyester is an optically active, main chain type or side chain type liquid crystalline polymer.

3. An optical rotator as set forth in claim 1, wherein said liquid crystalline polyester is a combination of a main chain type or side chain type liquid crystalline polyester which is not optically active and an optically active compound.

4. An optical rotator as set forth in claim 1, wherein said alignment film layer is a polyimide film which has been subjected to a rubbing treatment, an obliquely vapor-deposited film of silicon oxide, a polyvinyl alcohol film which has been subjected to a rubbing treatment, or a film obtained by subjecting a light transmitting base to a rubbing treatment directly.

5. An optical rotator as set forth in claim 1, wherein said liquid crystalline polyester film layer has a thickness in the range of 2 to 1,000 μ

m.