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US4698397A
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Cholesteric liquid crystal copolyesters
Assignee: NIPPON COMPANY Ltd A CORP OF JAPAN
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Filing: 1986-08-28
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Granted: 1987-10-06
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Expires: 2006-08-28
Abstract
Abstract A process for preparing a cholesteric liquid crystal copolyester consisting essentially of structural units represented by the following formula (A), (B), (C) and (D): <IMAGE> (A) OCH2CH2O (B) <IMAGE> (C) <IMAGE> (D) which is optically active characterized in that a polyethylene terephthalate oligomer having a (B)/(A) mole ratio in the range of 1.1 to 1.8, p-acetoxybenzoic acid and 3-methyladipic acid are reacted to prepare the final cholesteric liquid crystal copolyester having an inherent viscosity of at least 0.4 dl/g.
Inventors
- 👤 Tomohiro Toya
- 👤 Hajime Hara
- 👤 Shigeki Iida
- 👤 Tetsuo Satoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:45
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/60; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3804; C09K19/3809
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
72 words
A process for preparing a cholesteric liquid crystal copolyester consisting essentially of structural units represented by the following formula (A), (B), (C) and (D): ##STR3## which is optically active characterized in that a polyethylene terephthalate oligomer having a (B)/(A) mole ratio in the range of 1.1 to 1.8, p-acetoxybenzoic acid and 3-methyladipic acid are reacted to prepare the final cholesteric liquid crystal copolyester having an inherent viscosity of at least 0.4 dl/g.
Claim 2
Dependent Claim
72 words
A process for preparing a cholesteric liquid crystal copolyester consisting essentially of structural units represented by the following formula (A), (B), (C) and (D): ##STR3## which is optically active characterized in that a polyethylene terephthalate oligomer having a (B)/(A) mole ratio in the range of 1.1 to 1.8, p-acetoxybenzoic acid and 3-methyladipic acid are reacted to prepare the final cholesteric liquid crystal copolyester having an inherent viscosity of at least 0.4 dl/g.
Claim 3
Dependent Claim
26 words
A process as set forth in claim 1, wherein the (B)/(A) mole ratio of the polyethylene terephthalate oligomer is in the range of 1.2 to 1.5.
Claim 4
Dependent Claim
33 words
A process as set forth in claim 1, wherein said copolyester comprises 20-80 mole% of structural unit (C), 1-20 mole% of structural unit (D), and the balance of structural units (A) and (B).
Claim 5
Dependent Claim
33 words
A process as set forth in claim 1, wherein said copolyester comprises 30-70 mole% of structural unit (C), 2-15 mole% of structural unit (D), and the balance of structural units (A) and (B).
Claim 6
Dependent Claim
29 words
A process as set forth in claim 1, wherein the reaction is carried out in a molten condition at a temperature in the range of 200° to 350° C.
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) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |