US4197397A
Expired / Lapsed
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Chain-extending anhydride end-capped polyimides
Assignee: University of Notre Dame
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Filing: 1978-03-06
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Granted: 1980-04-08
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Expires: 1998-03-06
Abstract
Abstract Aromatic polyimides with anhydride end groups are chain-extended (molecular weight increased) by reacting them with aromatic diamines or diamine terminated imide oligomers. The reaction can either be at a temperature above the melting point of the reactants or in solvents for the reactants. These polyimides can be shaped and formed prior to chain-extending.
Inventors
- 👤 Gaetano F. D'Alelio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:12
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; C08G73/1003; C08G73/1007; C08G73/101; C08G73/1014
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
71 words
A polyimide-polyamic acid product having the repeating structural unit: ##STR25## wherein Ar' is a tetravalent aromatic organic radical, the four carbonyl groups being attached directly to separate carbon atoms and each pair of carbonyl groups being attached to adjacent carbon atoms in the Ar' radical. Ar is a divalent aromatic organic radical, n' is a positive integer of at least 1, and n is a positive integer of at least 2.
Claim 2
Dependent Claim
71 words
A polyimide-polyamic acid product having the repeating structural unit: ##STR25## wherein Ar' is a tetravalent aromatic organic radical, the four carbonyl groups being attached directly to separate carbon atoms and each pair of carbonyl groups being attached to adjacent carbon atoms in the Ar' radical. Ar is a divalent aromatic organic radical, n' is a positive integer of at least 1, and n is a positive integer of at least 2.
Claim 3
Dependent Claim
46 words
The product of claim 1 wherein Ar' is selected from the group consisting of ##STR26## Ar is selected from the group consisting of ##STR27## multiples thereof connected to each other by R IV , wherein R IV is alkylene of 1 to 3 carbon atoms, ##STR28##
Claim 4
Dependent Claim
9 words
The product of claim 2 wherein n is 4-20.
Claim 5
Dependent Claim
9 words
The product of claim 3 wherein n' is 4-20.
Claim 6
Dependent Claim
14 words
The product of claim 2 in which each of n and n' is 8-10.
Claim 7
Dependent Claim
99 words
A process for preparing the product of claim 1 comprising reacting a polyimide of the formula: ##STR29## with an aromatic diamine of the formula NH 2 ArNH 2 or a diamine terminated imide oligomer of the formula: ##STR30## in a solution of a phenol having the formula: ##STR31## wherein Ar, Ar', n and n' in all instances are as defined in claim 1 and R 1 is hydrogen or methyl, the mole ratio of said diamine or said oligomer to said polyimide being 1:1 to 2:1, and thereafter eliminating said phenol to increase the viscosity of the reaction product.
Claim 8
Dependent Claim
85 words
A process for preparing the product of claim 1 comprising reacting a polyimide of the formula: ##STR32## with an aromatic diamine of the formula NH 2 ArNH 2 or a diamine terminated imide oligomer of the formula: ##STR33## in a solution of phenol having the formula: ##STR34## wherein ar, Ar', n and n' in all instances are as defined in claim 1 and R 1 is hydrogen or methyl, the mole ratio of said diamine or said oligomer to said polyimide being 1:1 to 2:1.
Claim 9
Dependent Claim
15 words
The process of claim 7 wherein each of n and n' are 4 to 20.
Claim 10
Dependent Claim
17 words
The process of claim 6 wherein Ar' in formula (A), formula (B) or both formulas is ##STR35##
Claim 11
Dependent Claim
91 words
The process of claim 8 wherein Ar in formula (A), formula (B) or both formulas is selected from the group consisting of --C 6 H 4 CH 2 C 6 H 4 --, --C 6 H 4 SO 2 C 6 H 4 --, --C 6 H 4 --, --C 6 H 4 OC 6 H 4 SO 2 C 6 H 4 OC 6 H 4 --, --C 6 H 4 OC 6 H 4 OC 6 H 4 -- and --C 6 H 4 OC 6 H 4 --.
Claim 12
Dependent Claim
9 words
The product of claim 1 wherein n+n' is 8.
Claim 13
Dependent Claim
7 words
The product of claim 2 wherein ##STR36##
Claim 14
Dependent Claim
13 words
The process of claim 6 wherein said mole ratio is at least 1.1:1.
Claim 15
Dependent Claim
10 words
The process of claim 6 wherein said phenol is m-cresol.
Claim 16
Dependent Claim
18 words
The process of claim 6 where said phenol is removed from the reaction product by evaporation or distilation.
Claim 17
Dependent Claim
13 words
The process of claim 7 wherein said mole ratio is at least 1.1:1.
Claim 18
Dependent Claim
10 words
The process of claim 7 wherein said phenol is m-cresol.
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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |