Patent US4556682A successfully refreshed from Google Patents.
US4556682A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyimide compositions and foams and methods of making same
Assignee: IMI-TECH Corp ELK GROVE ILL A CORP OF
•
Filing: 1985-05-23
•
Granted: 1985-12-03
•
Expires: 2005-05-23
Abstract
Abstract Methods of making modified polyimide compositions and the resulting compositions. A polyimide forming material is prepared by treating an aromatic dianhydride with an esterifying solvent, then adding a suitable diamine. In order to obtain a foam which is non-friable and resistant to repeated compressive forces, the selected diamine must contain an aliphatic moiety in the chain. This material is dried to a powder or film. A foam is produced by heating the material to reaction temperature for a period sufficient to produce a stable foam. The material melts, then spontaneously expands into a foam which becomes self supporting and cures to a resilient, flexible non-friable foam.
Inventors
- 👤 John Gagliani
- 👤 John V. Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:21
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/02; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1025; C08G73/1028; C08G73/1032; C08J2379/00; C08J2379/04; C08J2379/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
110 words
A liquid polyimide foam precursor composition suitable for use in the manufacture of non-friable polyimide foams, prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR2## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
Claim 2
Dependent Claim
110 words
A liquid polyimide foam precursor composition suitable for use in the manufacture of non-friable polyimide foams, prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR2## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
Claim 3
Dependent Claim
124 words
A dry polyimide foam precursor composition suitable for use in the manufacture of non-friable polyimide foams, prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition drying said polyimide precursor composition and pulverizing the resulting dry material to a powder; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR3## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
Claim 4
Dependent Claim
124 words
A dry polyimide foam precursor composition suitable for use in the manufacture of non-friable polyimide foams, prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition drying said polyimide precursor composition and pulverizing the resulting dry material to a powder; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR3## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
Claim 5
Dependent Claim
132 words
A non-friable resilient, flame resistant polyimide foam prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition drying said polyimide precursor composition, pulverizing the resulting dry material to a powder and heating said powder to cause melting and foaming of said powder as the polymerization reaction is completed; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR4## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
Claim 6
Dependent Claim
132 words
A non-friable resilient, flame resistant polyimide foam prepared by esterifying an aromatic dianhydride with an esterifying solvent of produce a half-ester and reacting said half-ester with a diamine to produce a polyimide precursor composition drying said polyimide precursor composition, pulverizing the resulting dry material to a powder and heating said powder to cause melting and foaming of said powder as the polymerization reaction is completed; the improvement wherein: said diamine consists of a mixture of at least one aromatic-aliphatic diamine and from 0.1 to 50 mole % of at least one aliphatic diamine; said aromatic-aliphatic diamine having the general formula: ##STR4## wherein x is a positive integer from 1 to 20; and said aliphatic diamine has the general formula: H.sub.2 N--(CH.sub.2).sub.y --NH.sub.2 wherein y is a positive integer from 2 to 12.
References Cited (Backward Citations)
US30213A
Cited
US3726834A
Cited
US3793281A
Cited
US3966652A
Cited
USRE30213E
Cited
US4070312A
Cited
US4315080A
Cited
US4315077A
Cited
US4346182A
Cited
US4426463A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |