Patent US3671498A successfully refreshed from Google Patents.
US3671498A
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Copolyamides from bis(aminophenyl)sulfone
Assignee: Imperial Chemical Industries Ltd
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Filing: 1970-04-17
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Granted: 1972-06-20
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Expires: 1990-04-17
Abstract
Abstract The color of polyamides of bis(aminophenyl)sulphones and Alpha , omega -polymethylene dicarboxylic acids having from six to 16 carbon atoms in all, or mixtures of these acids with up to 25 mole percent of one or more other dicarboxylic acids, may be improved by replacing from 4 to 20 mole percent of the bis(aminophenyl)sulphone with a linear or branched alkylene diamine having the structure NH2CH2(CR1R2)mCH2NH2 where each R1 and R2 is hydrogen or an alkyl group having up to four carbon atoms and m is from 0 to 10 inclusive.
Inventors
- 👤 Michael Horace Knight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/42
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
18 words
A copolyamide as claimed in claim 1 in which Z is CH2 n in all the repeat units.
Claim 2
Dependent Claim
15 words
A copolyamide as claimed in claim 1 in which n is 4, 7 or 10.
Claim 3
Dependent Claim
31 words
A copolyamide as claimed in claim 1 in which n is from 4 to 7 and Z has the structure II in from 8 to 18 percent of the repeat units.
Claim 4
Dependent Claim
26 words
A copolyamide as claimed in claim 1 which is a copolymer of (i) bis(4-aminophenyl)sulphone, (ii) hexamethylene diamine, and (iii) adipic acid, azelaic acid or 1,10-decanedicarboxylic acid.
Claim 5
Dependent Claim
20 words
A copolyamide as claimed in claim 1 in which m is a whole number of from 0 to 2 inclusive.
Claim 6
Dependent Claim
23 words
A copolyamide as claimed in claim 1 in which the concentration of acid residues is less than 150 microequivalents per gram of polymer.
Claim 7
Dependent Claim
12 words
A film or fiber of the copolyamide as claimed in claim 1.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |