US4444980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal copolyesters
Assignee: Monsanto Co
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Filing: 1983-03-15
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Granted: 1984-04-24
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Expires: 2003-03-15
Abstract
Abstract Disclosed are liquid crystal copolyesters prepared from p-hydroxybenzoic acid, isophthalic acid, hydroquinone and 2,2-bis(4-hydroxyphenyl) propane.
Inventors
- 👤 Oliver D. Deex
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:39
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/60
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
152 words
A copolyester capable of forming a thermotropic melt phase at a temperature below about 340° C. and having a glass transition temperature of at least about 160° C. determined on a film of molded copolyester of 150 to 250 micron in thickness, by means of a dynamic tensile instrument operated at a frequency of 11 herz and a heating rate of 2° C. per minute and an inherent viscosity, determined at 30° C. with a solution of 0.5 gram of copolyester per 100 ml of a solvent composed of 60 parts by weight of phenol and 40 parts by weight of tetrachloroethane, of at least about 0.3, consisting essentially of the following divalent radicals: ##STR2## wherein the range of radical A is from 10 to 40 mol percent of the copolyester and the range of radical C is from 82 to 95 mole percent of the total of radicals C and D.
Claim 2
Dependent Claim
152 words
A copolyester capable of forming a thermotropic melt phase at a temperature below about 340° C. and having a glass transition temperature of at least about 160° C. determined on a film of molded copolyester of 150 to 250 micron in thickness, by means of a dynamic tensile instrument operated at a frequency of 11 herz and a heating rate of 2° C. per minute and an inherent viscosity, determined at 30° C. with a solution of 0.5 gram of copolyester per 100 ml of a solvent composed of 60 parts by weight of phenol and 40 parts by weight of tetrachloroethane, of at least about 0.3, consisting essentially of the following divalent radicals: ##STR2## wherein the range of radical A is from 10 to 40 mol percent of the copolyester and the range of radical C is from 82 to 95 mole percent of the total of radicals C and D.
Claim 3
Dependent Claim
21 words
The copolyester of claim 1 wherein the range of radical A is from 20 to 35 mole percent of the copolyester.
Claim 4
Dependent Claim
25 words
The copolyester of claim 2 wherein the range of radical C is 88 to 95 mole percent of the total of radicals C and D.
Claim 5
Dependent Claim
15 words
The copolyester of claim 2 or 3, wherein the inherent viscosity is at least 0.5.
References Cited (Backward Citations)
US4377681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-24 | 1987-10-24 | 1988-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-24 | 1991-10-24 | 1992-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-24 | 1995-10-24 | 1996-04-24 | $7700.00 | Window Closed / Lapsed |