US4535115A
Expired / Lapsed
US
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Method of preparation of polyimide acids
Assignee: Chevron USA Inc
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Filing: 1984-08-20
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Granted: 1985-08-13
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Expires: 2004-08-20
Abstract
Abstract A one-step solution technique for preparing an aromatic polyimide acid which comprises reacting an aromatic dianhydride with an aromatic diamine in the presence of diglyme and a sufficient amount of a co-solvent to maintain the polyimide acid in solution, said co-solvent having the formula: ROH where R is H, an aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms or a methoxy substituted aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms.
Inventors
- 👤 Kiran R. Bakshi
- 👤 Walter P. Barie
- 👤 Edward T. Sabourin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:49
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1032; C08G73/1067; C08G73/1071; C08L; C08L79/00; C08L79/04; C08L79/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
94 words
A one-step method for preparing a solution of an aromatic polyimide acid which comprises: reacting an aromatic dianhydride with an approximately equimolar quantity of an aromatic diamine to produce a polyimide acid in the presence of a solvent comprising diglyme and an amount of a co-solvent sufficient to maintain said polyimide acid in solution, said co-solvent having the formula: ROH where R can be H, an aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms or a methoxy substituted aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms.
Claim 2
Dependent Claim
94 words
A one-step method for preparing a solution of an aromatic polyimide acid which comprises: reacting an aromatic dianhydride with an approximately equimolar quantity of an aromatic diamine to produce a polyimide acid in the presence of a solvent comprising diglyme and an amount of a co-solvent sufficient to maintain said polyimide acid in solution, said co-solvent having the formula: ROH where R can be H, an aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms or a methoxy substituted aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms.
Claim 3
Dependent Claim
11 words
A method according to claim 1 wherein said co-solvent is water.
Claim 4
Dependent Claim
11 words
A method according to claim 1 wherein said co-solvent is methanol.
Claim 5
Dependent Claim
11 words
A method according to claim 1 wherein said co-solvent is ethanol.
Claim 6
Dependent Claim
21 words
A method according to claim 1 wherein the mol ratio of the co-solvent to aromatic diamine is from 0.5:1 to 5:1.
Claim 7
Dependent Claim
25 words
A method according to claim 1 wherein the dianhydride has the formula: ##STR7## where Z is selected from the group consisting of --O-- and ##STR8##
Claim 8
Dependent Claim
14 words
A method according to claim 6 wherein the dianhydride is 3,3',4,4'-benzophenone tetracarboxcyclic acid dianhydride.
Claim 9
Dependent Claim
26 words
A method according to claim 1 wherein the aromatic diamine has the formula: ##STR9## where Z is selected from the group consisting of --O-- and ##STR10##
Claim 10
Dependent Claim
12 words
A method according to claim 8 wherein the aromatic diamine is m,m'-diaminobenzophenone.
Claim 11
Dependent Claim
25 words
A method according to claim 5 wherein the co-solvent is water, the dianhydride is 3,3',4,4'-benzophenone tetracarboxcyclic acid dianhydride and the diamine is meta, meta' diaminobenzophenone.
Claim 12
Dependent Claim
43 words
A method according to claim 1 wherein the aromatic dianhydride is added to a slurry of the aromatic diamine, the solvent and co-solvent at a rate such that the temperature of reaction is maintained at a temperature below the temperature where imidization occurs.
Claim 13
Dependent Claim
16 words
A method according to claim 11 wherein the reaction temperature is less than about 40° C.
References Cited (Backward Citations)
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US4115341A
Cited
US4181641A
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US4255471A
Cited
US4332708A
Cited
US4382126A
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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) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |