US4026871A
Expired / Lapsed
US
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Chain-extending phenolic end-capped polyimides
Assignee: University of Notre Dame
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Filing: 1975-03-14
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Granted: 1977-05-31
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Expires: 1995-03-14
Abstract
Abstract Aromatic polyimides with phenolic end groups are chain-extended (molecular weight increased) by reacting them with formaldehyde, compounds capable of generating formaldehyde under the reaction conditions or hexamethylene tetramine in the presence of a catalytic amount of lime. These polyimides can be shaped and formed prior to the chain-extending. The aromatic polyimides appropriate for chain-extending are formed by the reaction of aromatic dianhydrides, aromatic diamines and phenolic compounds such as aminophenol.
Inventors
- 👤 Gaetano Francis D'Alelio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:00
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/64; C08G18/6415; C08G18/6438; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1057; C08G73/1064; C08G73/1067; C08G73/1071; Y; Y10; Y10S; Y10S525/00; Y10S525/925; Y10S525/928
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
146 words
A polymeric chain-extending process comprising: heating at a temperature in the range of about 150°-450° C. a polyimide having the formula ##STR21## wherein Ar' is a tetravalent aromatic organic radical, the four carbonyl groups being attached directly to separated 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, R is an aromatic hydrocarbon radical of 6 to 12 carbon atoms, and n is a positive integer of at least one with a chain-extending material selected from the group consisting of formaldehyde, a compound capable of generating formaldehyde under the reaction conditions and hexamethylene tetramine in the presence of about 1-5% by weight, based on the weight of polyimide, of lime, and wherein the amount of formaldehyde present or generated is about 5-25% by weight, based on the weight of polyimide.
Claim 2
Dependent Claim
146 words
A polymeric chain-extending process comprising: heating at a temperature in the range of about 150°-450° C. a polyimide having the formula ##STR21## wherein Ar' is a tetravalent aromatic organic radical, the four carbonyl groups being attached directly to separated 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, R is an aromatic hydrocarbon radical of 6 to 12 carbon atoms, and n is a positive integer of at least one with a chain-extending material selected from the group consisting of formaldehyde, a compound capable of generating formaldehyde under the reaction conditions and hexamethylene tetramine in the presence of about 1-5% by weight, based on the weight of polyimide, of lime, and wherein the amount of formaldehyde present or generated is about 5-25% by weight, based on the weight of polyimide.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein ##STR22## and n is at least 4.
Claim 4
Dependent Claim
57 words
The process of claim 1 wherein Ar' is selected from the group consisting of ##STR23## and Ar is selected from the group consisting of ##STR24## and multiples thereof connected to each other by R IV , wherein R IV is alkylene of 1 to 3 carbon atoms, ##STR25## --O-- , --S-- , --CH═CH--, and --SO 2 --.
Claim 5
Dependent Claim
115 words
A polymeric chain-extending process comprising: heating a polyimide at a temperature in the range of about 150°-450° C. with about 5-25% by weight, based on the weight of polyimide, of formaldehyde or paraformaldehyde and about 1-5% by weight, based on the weight of polyimide, of lime, said polyimide of the formula: ##STR26## Ar' is selected from the group consisting of ##STR27## and Ar is selected from the group consisting of ##STR28## and multiples thereof connected to each other by R IV , wherein R IV is alkylene of 1 to 3 carbon atoms, ##STR29## --O-- , --S-- , --CH═CH-- , and --SO 2 -- ##STR30## and n is a positive integer of at least 1.
Claim 6
Dependent Claim
115 words
A polymeric chain-extending process comprising: heating a polyimide at a temperature in the range of about 150°-450° C. with about 5-25% by weight, based on the weight of polyimide, of formaldehyde or paraformaldehyde and about 1-5% by weight, based on the weight of polyimide, of lime, said polyimide of the formula: ##STR26## Ar' is selected from the group consisting of ##STR27## and Ar is selected from the group consisting of ##STR28## and multiples thereof connected to each other by R IV , wherein R IV is alkylene of 1 to 3 carbon atoms, ##STR29## --O-- , --S-- , --CH═CH-- , and --SO 2 -- ##STR30## and n is a positive integer of at least 1.
Claim 7
Dependent Claim
26 words
The process of claim 4 wherein the formaldehyde or paraformaldehyde is at a concentration of about 10-15% by weight and n is from 1 to 20.
Claim 8
Dependent Claim
10 words
A cross-linked polymer prepared by the process of claim 1.
Claim 9
Dependent Claim
10 words
A cross-linked polymer prepared by the process of claim 4.
Claim 10
Dependent Claim
10 words
A cross-linked polymer prepared by the process of claim 5.
Claim 11
Dependent Claim
87 words
The product of claim 6 wherein ##STR31## and Ar 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 OC 6 H 4 SO 2 C 6 H 4 OC 6 H 4 -- , --C 6 H 4 OC 6 OC 6 H 4 -- , --C 6 H 4 OC 6 H 4 -- , and --C 6 H 4 --.
Claim 12
Dependent Claim
90 words
The product of claim 7 wherein ##STR32## and Ar 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 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 -- , --C 6 H 4 OC 6 H 4 -- , and --C 6 H 4 -- .
Claim 13
Dependent Claim
87 words
The product of claim 7 wherein ##STR33## and Ar 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 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 --, --C 6 H 4 OC 6 H 4 -- , and --C 6 H 4 --.
Claim 14
Dependent Claim
89 words
The product of claim 8 wherein ##STR34## and Ar 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 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 -- , --C 6 H 4 OC 6 H 4 -- , and --C 6 H 4 --.
Claim 15
Dependent Claim
22 words
The process of claim 1 wherein the chain-extending material is an addition product of formaldehyde and a phenol having 2 methylol functions.
Claim 16
Dependent Claim
22 words
The process of claim 1 wherein the chain-extending material is an addition compound of formaldehyde and melamine having from 3-6 methylol functions.
Claim 17
Dependent Claim
17 words
The process of claim 1 wherein the chain-extending material is a substituted formaldehyde having two --CHO functions.
Claim 18
Dependent Claim
11 words
The process of claim 15 wherein the substituted formaldehyde is furfuraldehyde.
Claim 19
Dependent Claim
129 words
A polymeric chain-extending process comprising: heating at a temperature in the range of about 150°-450° C. a polyimide having the formula ##STR35## 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, R is an aromatic hydrocarbon radical of 6 to 12 carbon atoms, and n is a positive integer of at least one with a chain-extending material selected from the group consisting of formaldehyde, a compound capable of generating formaldehyde under the reaction conditions and hexamethylene tetramine, wherein the amount of formaldehyde present or generated is about 5-25% by weight, based on the weight of polyimide.
Claim 20
Dependent Claim
129 words
A polymeric chain-extending process comprising: heating at a temperature in the range of about 150°-450° C. a polyimide having the formula ##STR35## 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, R is an aromatic hydrocarbon radical of 6 to 12 carbon atoms, and n is a positive integer of at least one with a chain-extending material selected from the group consisting of formaldehyde, a compound capable of generating formaldehyde under the reaction conditions and hexamethylene tetramine, wherein the amount of formaldehyde present or generated is about 5-25% by weight, based on the weight of polyimide.
Claim 21
Dependent Claim
10 words
A cross-linked polymer prepared by the process of claim 17.
References Cited (Backward Citations)
US3437636A
Cited
US3442861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |