US4607093A
Expired / Lapsed
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Sydnone based polyimide
Assignee: Dow Chemical Co
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Filing: 1985-04-08
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Granted: 1986-08-19
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Expires: 2005-04-08
Abstract
Abstract Novel amorphous polyimides are provided which are formed by the polymerization of bismaleimides with sydnones wherein carbon dioxide is evolved. The polyimides are readily soluble in dipolar aprotic solvents and are further characterized by high temperature stability to at least 300° C. The polymers find particular utility in the form of films and solutions useful for wire enamel and electrical coatings.
Inventors
- 👤 Kwok K. Sun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:17
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1085
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
72 words
A polyimide having the recurring unit wherein R represents a divalent radical selected from the group consisting of alkylene, arylene containing radical, and cycloalkylene; R 1 is hydrocarbyl; R 2 is selected from the group consisting of hydrogen and hydrocarbyl; and R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, and lower alkyl of C 1 to C 4 .
Claim 2
Dependent Claim
72 words
A polyimide having the recurring unit wherein R represents a divalent radical selected from the group consisting of alkylene, arylene containing radical, and cycloalkylene; R 1 is hydrocarbyl; R 2 is selected from the group consisting of hydrogen and hydrocarbyl; and R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, and lower alkyl of C 1 to C 4 .
Claim 3
Dependent Claim
33 words
A polyimide according to claim 1 wherein R 1 is aryl, R 2 is hydrogen or alkyl, and R 3 , R 4 , R 5 , and R 6 are all hydrogen.
Claim 4
Dependent Claim
10 words
A polyimide according to claim 2 wherein R is alkylene.
Claim 5
Dependent Claim
10 words
A polyimide according to claim 2 wherein R is arylene.
Claim 6
Dependent Claim
33 words
A polyimide according to claim 1 wherein R is 4,4'-methylenebisphenylene, R 1 is phenyl, and R 2 , R 3 , R 4 , R 5 , and R 6 are all hydrogen.
Claim 7
Dependent Claim
33 words
A polyimide according to claim 1 wherein R is 4,4'-oxybisphenylene, R 1 is phenyl, and R 2 , R 3 , R 4 , R 5 , and R 6 are all hydrogen.
Claim 8
Dependent Claim
34 words
A polyimide according to claim 1 wherein R is 4,4'-methylenebisphenylene, R 1 is phenyl, R 2 is methyl, and R 3 , R 4 , R 5 , and R 6 are all hydrogen.
Claim 9
Dependent Claim
32 words
A polyimide according to claim 1 wherein R is 1,2-ethylene, R 1 is phenyl, and R 2 , R 3 , R 4 , R 5 and R 6 are all hydrogen.
Claim 10
Dependent Claim
13 words
A polyimide according to claim 1 in the form of a cellular foam.
Claim 11
Dependent Claim
112 words
A process for the preparation of a polyimide in accordance with claim 1 said process comprising heating together in substantially equimolar proportions A. a bismaleimide having the formula ##STR7## wherein R represents a divalent radical selected from the group consisting of alkylene, arylene containing radical, and cycloalkylene; R 3 , R 4 , R 5 and R 6 are independently selected from the group consisting of hydrogen, and lower alkyl of C 1 to C 4 ; and B. a sydnone having the formula ##STR8## wherein R 1 is hydrocarbyl and R 2 is selected from the group consisting of hydrogen and hydrocarbyl at a temperature sufficiently high to eliminate carbon dioxide.
Claim 12
Dependent Claim
19 words
A process according to claim 10 wherein said (A) and said (B) are heated together in an inert solvent.
Claim 13
Dependent Claim
14 words
A process according to claim 11 wherein said solvent is a dipolar aprotic solvent.
Claim 14
Dependent Claim
24 words
A process according to claim 10 wherein said heating is carried out at a temperature of from about 75° C. to about 250° C.
Claim 15
Dependent Claim
79 words
A process according to claim 10 wherein A. a bismaleimide having the formula ##STR9## wherein R represents a divalent radical selected from the group consisting of alkylene, arylene containing radical, and cycloalkylene is heated together in substantially equimolar proportions with B. a sydnone having the formula ##STR10## wherein R 1 is aryl and R 2 is hydrogen or alkyl in an inert solvent at a temperature of from about 75° C. to about 250° C. to eliminate carbon dioxide.
Claim 16
Dependent Claim
25 words
A process according to claim 14 wherein said solvent is tetramethylene sulfone and the temperature range is from about 90° C. to about 150° C.
Claim 17
Dependent Claim
14 words
A process according to claim 15 wherein (A) is methylenebis(4-maleimidobenzene) and (B) is 3-phenylsydnone.
Claim 18
Dependent Claim
14 words
A process according to claim 15 wherein (A) is oxybis(4-maleimidobenzene) and (B) is 3-phenylsydnone.
Claim 19
Dependent Claim
14 words
A process according to claim 15 wherein (A) is methylenebis(4-maleimidobenzene) and (B) is 3-phenyl-4-methylsydnone.
Claim 20
Dependent Claim
14 words
A process according to claim 15 wherein (A) is N,N'-ethylenebismaleimide and (B) is 3-phenylsydnone.
Claim 21
Dependent Claim
44 words
A process in accordance with claim 10 for the preparation of said polyimide in the form of a cellular foam said process comprising heating said reactants (A) and (B) in the absence of solvent and at a temperature sufficiently high to eliminate carbon dioxide.
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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |