US4408840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal compositions containing pleochroic anthraquinone dyes, liquid crystal devices containing the compositions, and the dyes
Assignee: Hitachi Ltd
•
Filing: 1981-09-22
•
Granted: 1983-10-11
•
Expires: 2001-09-22
Abstract
Abstract A liquid crystal composition contains a pleochroic dye which is an anthraquinone dye having the group -OCOO- in a substituent group. Such a dye shows a reasonable order parameter and good solubility as well as stability in the liquid crystal composition.
Inventors
- 👤 Shuji Imazeki
- 👤 Akio Mukoh
- 👤 Mikio Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:35
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/60; C09K19/603
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
35 words
A liquid crystal composition containing a pleochroic anthraquinone dye, said dye having one of the two following formulae I and II: ##STR24## wherein R 1 is selected from the group consisting of alkyl and cycloalkyl.
Claim 2
Dependent Claim
35 words
A liquid crystal composition containing a pleochroic anthraquinone dye, said dye having one of the two following formulae I and II: ##STR24## wherein R 1 is selected from the group consisting of alkyl and cycloalkyl.
Claim 3
Dependent Claim
34 words
A liquid crystal composition as claimed in claim 1, wherein R 1 is selected from the group consisting of n-C 4 H 9 , n-C 7 H 15 and n-C 9 H 19 .
Claim 4
Dependent Claim
18 words
A liquid crystal composition as claimed in claim 1 or 2, which further includes an optically active substance.
Claim 5
Dependent Claim
105 words
A liquid crystal device comprising (a) a pair of spaced apart plates, at least one of which is transparent, arranged with a space between them, (b) a pair of layer electrodes respectively on said plates, (c) a liquid crystal composition located in said space between the plates, said composition comprising (i) a liquid crystal material having positive dielectric anisotropy forming a host material and (ii) a pleochroic anthraquinone dye dissolved in said liquid crystal material as a guest material, said dye having one of the two following formulae I and II ##STR25## wherein R 1 is selected from the group consisting of alkyl and cycloalkyl.
Claim 6
Dependent Claim
105 words
A liquid crystal device comprising (a) a pair of spaced apart plates, at least one of which is transparent, arranged with a space between them, (b) a pair of layer electrodes respectively on said plates, (c) a liquid crystal composition located in said space between the plates, said composition comprising (i) a liquid crystal material having positive dielectric anisotropy forming a host material and (ii) a pleochroic anthraquinone dye dissolved in said liquid crystal material as a guest material, said dye having one of the two following formulae I and II ##STR25## wherein R 1 is selected from the group consisting of alkyl and cycloalkyl.
Claim 7
Dependent Claim
46 words
A liquid crystal device as claimed in claim 4, wherein said liquid crystal material having positive dielectric anisotropy comprises a liquid crystal material having a negative dielectric and mixed with liquid crystals having a positive dielectric anisotropy so that the resulting mixture has positive dielectric anisotropy.
References Cited (Backward Citations)
EP0002104A1
Cited
DE2920730A1
Cited
JPS55127485A
Cited
DE3028593A1
Cited
JPS5638376A
Cited
EP0026004A1
Cited
DE3036853A1
Cited
JPS56112967A
Cited
US4308164A
Cited
US4308161A
Cited
US4308163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |