US4154746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anthraquinone amino pleochroic dyes
Assignee: 3M Co
•
Filing: 1978-05-24
•
Granted: 1979-05-15
•
Expires: 1998-05-24
Abstract
Abstract Anils of 1,4- and 1,8-diaminoanthraquinone with p-alkyl- and p-alkoxybenzaldehyde are found to be pleochroic dyes which form guest-host combinations with dielectrically positive anisotropic nematic liquid crystals. These combinations are of value in electro-optical display devices.
Inventors
- 👤 William A. Huffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:57
CPC Classifications
C; C09; C09B; C09B1/00; C09B1/16; C09B1/20; C09B1/205; C09K; C09K19/00; C09K19/52; C09K19/60; C09K19/603
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
51 words
A pleochroic dyestuff of the general formula ##STR7## where C 14 H 6 O 2 is an anthraquinone radical having valences at 1,4 or 1,8 and X is nitro, cyano, phenyl, alkyl of 1-20 carbon atoms, alkoxy of 1-20 carbon atoms or di(lower alkyl)amino containing alkyl groups of 1-4 carbon atoms.
Claim 2
Dependent Claim
51 words
A pleochroic dyestuff of the general formula ##STR7## where C 14 H 6 O 2 is an anthraquinone radical having valences at 1,4 or 1,8 and X is nitro, cyano, phenyl, alkyl of 1-20 carbon atoms, alkoxy of 1-20 carbon atoms or di(lower alkyl)amino containing alkyl groups of 1-4 carbon atoms.
Claim 3
Dependent Claim
12 words
The pleochroic dyestuff according to claim 1 represented by the structure ##STR8##
Claim 4
Dependent Claim
12 words
The pleochroic dyestuff according to claim 1 represented by the structure ##STR9##
References Cited (Backward Citations)
US1930351A
Cited
US4078086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |