US4140846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal copolyesters containing 4-carboxybenzenepropionic acid
Assignee: Eastman Chemical Co
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Filing: 1978-05-04
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Granted: 1979-02-20
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Expires: 1998-05-04
Abstract
Abstract Disclosed are liquid crystal copolyesters having enhanced heat stability. The copolyesters are prepared from 4-carboxybenzenepropionic acid, a diacyl ester of hydroquinone and a p-acyloxybenzoic acid and contain the following divalent radicals: <IMAGE> (A) <IMAGE> (B) <IMAGE>
Inventors
- 👤 Winston J. Jackson, Jr.
- 👤 Herbert F. Kuhfuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:31
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/18; C08G63/60; C08G63/605
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
36 words
A copolyester having a fiber-forming molecular weight consisting essentially of the following divalent radicals: ##STR14## wherein the range of radical (C) is 10 to 90 mole percent, based on the sum of radicals (A) and (C).
Claim 2
Dependent Claim
36 words
A copolyester having a fiber-forming molecular weight consisting essentially of the following divalent radicals: ##STR14## wherein the range of radical (C) is 10 to 90 mole percent, based on the sum of radicals (A) and (C).
Claim 3
Dependent Claim
18 words
The copolyester of claim 1 wherein the range of radical (C) is from 30 to 80 mole percent.
References Cited (Backward Citations)
US3368998A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |