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US4477368A
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Color display liquid crystal composition
Assignee: Alps Alpine Co Ltd
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Filing: 1982-09-30
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Granted: 1984-10-16
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Expires: 2002-09-30
Abstract
Abstract A color display liquid crystal composition comprising a nematic liquid crystal having positive dielectric anisotropy, an optically active substance and a dichroic dye mixture consisting of a dichroic reddish purple diazo dye (1,4-naphthylene derivative) and a dichroic red diazo dye (1,4-phenylene derivative). This composition is suitable for use in a guest-host type color liquid crystal display device.
Inventors
- 👤 Fumiaki Yamanashi
- 👤 Yuzo Hayashi
- 👤 Mitsuru Kano
- 👤 Yoshiyuki Fujiwara
- 👤 Yoshizo Tashiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:21
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/60; C09K19/601; C09B; C09B31/00; C09B31/02; C09B31/04; C09B31/043
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
A color display liquid crystal mixture useful in phase transition type negative color liquid crystal display devices comprising a nematic liquid crystal having positive dielectric anisotropy, an optically active substance and from 0.4 to 0.9 wt. % of a dichroic dye mixture comprising 60 to 95 wt % of a dichroic reddish purple diazo dye which is a 1,4-naphthylene derivative of the structural formula: ##STR23## wherein R 1 represents an alkyl group containing up to 5 carbon atoms and R 2 represents ##STR24## or ##STR25## in which R and R' each represent a lower alkyl group and n represents an integer of at least 4, and 40 to 5 wt % of a dichroic red diazo dye which is a 1,4-phenylene derivative of the structural formula: ##STR26## wherein R 3 represents an alkyl group containing up to 5 carbon atoms and R 4 represents ##STR27## or ##STR28## in which R" and R"' each represent a lower alkyl group and n represents an integer of at least 4.
Claim 2
Dependent Claim
167 words
A color display liquid crystal mixture useful in phase transition type negative color liquid crystal display devices comprising a nematic liquid crystal having positive dielectric anisotropy, an optically active substance and from 0.4 to 0.9 wt. % of a dichroic dye mixture comprising 60 to 95 wt % of a dichroic reddish purple diazo dye which is a 1,4-naphthylene derivative of the structural formula: ##STR23## wherein R 1 represents an alkyl group containing up to 5 carbon atoms and R 2 represents ##STR24## or ##STR25## in which R and R' each represent a lower alkyl group and n represents an integer of at least 4, and 40 to 5 wt % of a dichroic red diazo dye which is a 1,4-phenylene derivative of the structural formula: ##STR26## wherein R 3 represents an alkyl group containing up to 5 carbon atoms and R 4 represents ##STR27## or ##STR28## in which R" and R"' each represent a lower alkyl group and n represents an integer of at least 4.
Claim 3
Dependent Claim
24 words
A color display liquid crystal mixture as in claim 1 wherein the 1,4-naphthalene derivative and 1,4-phenylene derivative are represented by the following formulas: ##STR29##
Claim 4
Dependent Claim
24 words
A color display liquid crystal mixture as in claim 1 wherein the 1,4-naphthalene derivative and 1,4-phenylene derivative are represented by the following formulas: ##STR30##
Claim 5
Dependent Claim
24 words
A color display liquid crystal mixture as in claim 1 wherein the 1,4-naphthalene derivative and 1,4-phenylene derivative are represented by the following formulas: ##STR31##
Claim 6
Dependent Claim
24 words
A color display liquid crystal mixture as in claim 1 wherein the 1,4-naphthalene derivative and 1,4-phenylene derivative are represented by the following formulas: ##STR32##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |