Patent US3929691A successfully refreshed from Google Patents.
US3929691A
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Solutions of copolymers containing amide and imide groups and process for their preparation
Assignee: Rhodiaceta SA
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Filing: 1969-12-29
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Granted: 1975-12-30
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Expires: 1989-12-29
Abstract
Abstract The invention provides wet- or dry-spinnable solutions of high molecular weight polyamide-polyimide copolymers derived from an aromatic diisocyanate, an aromatic or heterocyclic diacid, an aromatic anhydride acid and, optionally, an aromatic dianhydride, in polar solvents such as N-methylpyrrolidone.
Inventors
- 👤 Pierre Allard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:33
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/14; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/34; C08G18/343
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
26 words
A SPINNABLE SOLUTION CONSISTING ESSENTIALLY OF A HIGH MOLECULAR WEIGHT POLYAMIDE-POLYIMIDE COPOLYMER DISSOLVED IN A POLAR SOLVENT, SAID COPOLYMER CONSISTING ESSENTIALLY OF UNITS O THE FORMULA:
Claim 2
Dependent Claim
26 words
A SPINNABLE SOLUTION CONSISTING ESSENTIALLY OF A HIGH MOLECULAR WEIGHT POLYAMIDE-POLYIMIDE COPOLYMER DISSOLVED IN A POLAR SOLVENT, SAID COPOLYMER CONSISTING ESSENTIALLY OF UNITS O THE FORMULA:
Claim 3
Dependent Claim
17 words
A spinnable solution according to claim 1, in which Ar2 is m-or p-phenylene or a mixture thereof.
Claim 4
Dependent Claim
35 words
A spinnable solution according to claim 1, in which the copolymer contains from 5 to 60 mole % of the units of formula: -NH - Ar1 - NH - CO - Ar2 - CO -.
Claim 5
Dependent Claim
32 words
A spinnable solution according to claim 1, in which the copolymer has an inherent viscosity between 0.8 and 1.2, as measured by using an 0.5% strength solution thereof in N-methylpyrrolidone at 25*C.
Claim 6
Dependent Claim
17 words
A spinnable solution according to claim 1, in which the polar solvent is N-methylpyrrolidone, dimethylformamide or dimethylacetamide.
Claim 7
Dependent Claim
60 words
A process for preparing a spinnable solution consisting essentially of the high molecular weight polyamide-polyimide copolymer defined in claim 1, comprising reacting in an anhydrous polar solvent that is essentially inert with respect to said copolymer, reactants in substantially stoichometric proportions that consist essentially of a diisocyanate of formula: OCN - Ar1 - NCO an aromatic anhydride acid of formula:
Claim 8
Dependent Claim
19 words
A process according to claim 6, in which the polar solvent contains less than 3000 ppm of residual water.
Claim 9
Dependent Claim
20 words
A process according to claim 7, in which the polar solvent contains between 100 and 1000 ppm of residual water.
Claim 10
Dependent Claim
31 words
A process according to claim 6, in which the concentration of the reactants is such that the solids content of the solution after reaction is between 18 and 35% by weight.
Claim 11
Dependent Claim
17 words
A process according to claim 6, in which said concentration is between 21 and 28% by weight.
References Cited (Backward Citations)
US3300420A
Cited
US3314923A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |