US3950264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Schiff-base liquid crystals doped to raise dynamic scattering cutoff frequency
Assignee: Boeing North American Inc
•
Filing: 1973-05-07
•
Granted: 1976-04-13
•
Expires: 1993-05-07
Abstract
Abstract When a nematic liquid crystal has been doped to maximize its contrast ratio, its cutoff frequency (that above which all dynamic scattering ceases) can be further increased up to about 500% by adding small amounts of an ionic dpoant to the doped nematic crystal. The ionic dopant is R 1 R 2 R 3 R 4 N +B - (R 5 ) 4 , where R 1 , R 2 , R 3 , R 4 and R 5 may be the same or different alkyl or aryl groups. The alkyl groups having the formula CH 3 (CH 2 ) n , where n is a positive integer or zero and the aryl groups being either phenyl or biphenyl. Ammonium boride -18 , (C 18 H 37 ) 2 (CH 3 ) 2 N +B - (C 6 H 5 ) 4 , is the preferred ionic dopant.
Inventors
- 👤 Freeman B. Jones, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:39
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/58; C09K19/582; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13743; G02F1/1375
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
74 words
A dynamic scattering type nematic liquid crystal doped with an ionic dopant of the formula (R 1 ) 2 (R 2 ) 2 N +B - (R 3 ) 4 where R 1 , R 2 and R 3 are each selected from the group consisting of phenyl, biphenyl and CH 3 (CH 2 ) n , where n is a positive integer or zero and R 1 and R 2 are different groups.
Claim 2
Dependent Claim
74 words
A dynamic scattering type nematic liquid crystal doped with an ionic dopant of the formula (R 1 ) 2 (R 2 ) 2 N +B - (R 3 ) 4 where R 1 , R 2 and R 3 are each selected from the group consisting of phenyl, biphenyl and CH 3 (CH 2 ) n , where n is a positive integer or zero and R 1 and R 2 are different groups.
Claim 3
Dependent Claim
30 words
The composition of claim 1 wherein the ionic dopant is (C 18 H 37 ) 2 (CH 3 ) 2 N +B - (C 6 H 5 ) 4 .
Claim 4
Dependent Claim
74 words
A Schiff-base dynamic scattering-type nematic liquid crystal doped with an ionic dopant of the formula (R 1 ) 2 (R 2 ) 2 N +B - (R 3 ) 4 where R 1 , R 2 and R 3 are each selected from the group consisting of phenyl, biphenyl and CH 3 (CH 2 ) n , where n is a positive integer or zero and R 1 and R 2 are different groups.
Claim 5
Dependent Claim
74 words
A Schiff-base dynamic scattering-type nematic liquid crystal doped with an ionic dopant of the formula (R 1 ) 2 (R 2 ) 2 N +B - (R 3 ) 4 where R 1 , R 2 and R 3 are each selected from the group consisting of phenyl, biphenyl and CH 3 (CH 2 ) n , where n is a positive integer or zero and R 1 and R 2 are different groups.
Claim 6
Dependent Claim
35 words
A Schiff-base dynamic scattering-type nematic liquid crystal doped with an ionic dopant of the formula (C 18 H 37 ) 2 (CH 3 ) 2 N +B - (C 6 H 5 ) 4 .
Claim 7
Dependent Claim
35 words
A Schiff-base dynamic scattering-type nematic liquid crystal doped with an ionic dopant of the formula (C 18 H 37 ) 2 (CH 3 ) 2 N +B - (C 6 H 5 ) 4 .
Claim 8
Dependent Claim
11 words
The composition of claim 4 wherein the dopant constitutes 50 ppm.
Claim 9
Dependent Claim
22 words
The liquid crystal of claim 5 wherein the mixture is further doped with 0.5 weight % p-aminophenol and 10 ppm p-toluenesulfonic acid.
Claim 10
Dependent Claim
20 words
The liquid crystal of claim 6 wherein the nematic material is substantially 55% 4-methoxybenzylidene-4'-n-butylaniline and substantially 45% 4-ethoxybenzylidene-4'-n-butylaniline by weight.
Claim 11
Dependent Claim
20 words
The liquid crystal of claim 3 wherein the nematic material is substantially 55% 4-methoxybenzylidene-4'-n-butylaniline and substantially 45% 4-ethoxybenzylidene-4'-n-butylaniline by weight.
References Cited (Backward Citations)
US3597043A
Cited
US3656834A
Cited
US3697150A
Cited
US3698449A
Cited
US3803050A
Cited
US3756694A
Cited
US3816113A
Cited
US3838059A
Cited
US3809456A
Cited
US3814700A
Cited
US3904797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |