US3897393A
Expired / Lapsed
US
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Polyimides from bismaleimides and heterocyclic disecondary diamines
Assignee: Zeneca Inc
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Filing: 1973-11-29
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Granted: 1975-07-29
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Expires: 1993-11-29
Abstract
Abstract Polyimide polymers having an intrinsic viscosity of at least 0.2 dl/g in m-cresol at 25*C. are prepared by reacting a bismaleimide with a difunctional heterocyclic disecondary amine in a phenolic solvent for a time sufficient to form a polymer containing recurring imide units.
Inventors
- 👤 Robert T Lu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:27
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
24 words
IN A PROCESS FOR THE PREPARATION OF A POLYIMIDE POLYMER BY REACTING A BISMALEIMIDE WITH A DEFUNCTIONAL HETEROCYCLIC DISECONDARY AMINE CHARACTERIZED BY THE FORMULA
Claim 2
Dependent Claim
24 words
IN A PROCESS FOR THE PREPARATION OF A POLYIMIDE POLYMER BY REACTING A BISMALEIMIDE WITH A DEFUNCTIONAL HETEROCYCLIC DISECONDARY AMINE CHARACTERIZED BY THE FORMULA
Claim 3
Dependent Claim
23 words
A process of claim 1 wherein the solvent is phenol, o-cresol, m-cresol, p-cresol, 2,6-xylenol, mixtures of o-cresol, p-cresol, and m-cresol, p-chlorophenol, and p-ethylphenol.
Claim 4
Dependent Claim
13 words
A process of claim 2 wherein the bismaleimide is characterized by the formula
Claim 5
Dependent Claim
13 words
A process of claim 2 wherein the difunctional heterocyclic disecondary amine is piperazine.
Claim 6
Dependent Claim
27 words
A process of claim 2 wherein the bismaleimide is selected from the group consisting of methylene bis(4-maleimido benzene), N,N''-4,4''-diphenyl ether bismaleimide, N,N''-4,4''-diphenyl sulphone bismaleimide, and phenylene bismaleimide.
Claim 7
Dependent Claim
44 words
A process of claim 5 wherein the difunctional heterocyclic disecondary amine is piperazine, the temperature is from 20* to 120 *C., and the total concentration of the bismaleimide and piperazine is from 10 to 30% by weight, based on the total weight of solution.
Claim 8
Dependent Claim
64 words
A process of claim 1 wherein the polyimide polymer is precipitated from solution by mixing the polyimide solution with a precipitating agent characterized by having a boiling point below about 150*C., by being miscible with the solvent used to prepare the polyimide polymer, and by being a non-solvent for the polyimide polymer, and wherein the precipitated polyimide polymer is separated from the liquid phase.
Claim 9
Dependent Claim
16 words
A polyimide powder prepared by drying a polyimide polymer obtained by the process of claim 7.
Claim 10
Dependent Claim
26 words
A process of claim 2 wherein the total concentration of bismaleimide and difunctional heterocyclic disecondary amine in the solvent is from 10 to 30% by weight.
Claim 11
Dependent Claim
16 words
A polyimide polymer of a bismaleimide and a difunctional heterocyclic disecondary amine characterized by the formula
Claim 12
Dependent Claim
16 words
A polyimide polymer of a bismaleimide and a difunctional heterocyclic disecondary amine characterized by the formula
References Cited (Backward Citations)
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US3625912A
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US3669930A
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US3679639A
Cited
US3652511A
Cited
US3637901A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |