Patent JPS6453744A successfully refreshed from Google Patents.
US4476254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density, modified polyimide foams and methods of making same
Assignee: IMI-TECH Corp ELK GROVE ILL A CORP OF
•
Filing: 1984-03-07
•
Granted: 1984-10-09
•
Expires: 2004-03-07
Abstract
Abstract Methods of making low density modified polyimide/polyimide-amide foams and the resulting compositions. An N-substituted aliphatic imide is prepared by reacting a suitable aromatic dianhydride with a suitable oxime. A polyimide forming material is prepared by dissolving the N-substituted aliphatic imide in an esterifying solvent, then adding a suitable aromatic diamine. This material is dried to a powder. A suitable hydrated compound which is stable up to at least about 100° C. is mixed with the powder. A foam is then 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 foam. The addition of the hydrated compound is found to result in an exceptionally low density foam. Depending upon heating conditions, a polyimide, polyimide-amide or mixture thereof may be produced, resulting in foams having selectively variable physical properties.
Inventors
- 👤 John V. Long
- 👤 John Gagliani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:34
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/34; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028; C08J9/02; C08L; C08L79/00; C08L79/04; C08L79/08; C08J2379/00; C08J2379/04; C08J2379/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
146 words
A low density, resilient, flame resistant modified polyimide foam product obtained according to the following method steps: reacting an aromatic dianhydride with an effective amount of an oxoimine having the general formula ##STR8## where "x" is an integer from 1 to 5, in a mole ratio of oxime to dianhydride up to about 1.5:1 to produce an N-substituted aliphatic imide; dissolving said imide in a reactive solvent esterfying agent to exterify said imide; adding thereto a diamine; drying the resulting solution to produce a powdered prepolymer; blending with said powdered prepolymer from about 0.05 to 10 wt. %, based on prepolymer weight, of a hydrated compound which is stable up to at least about 100° C.; and heating the blended material to a selected foaming temperature of from about 120° C. to about 320° C. for a period of from about 10 to about 60 minutes.
Claim 2
Dependent Claim
146 words
A low density, resilient, flame resistant modified polyimide foam product obtained according to the following method steps: reacting an aromatic dianhydride with an effective amount of an oxoimine having the general formula ##STR8## where "x" is an integer from 1 to 5, in a mole ratio of oxime to dianhydride up to about 1.5:1 to produce an N-substituted aliphatic imide; dissolving said imide in a reactive solvent esterfying agent to exterify said imide; adding thereto a diamine; drying the resulting solution to produce a powdered prepolymer; blending with said powdered prepolymer from about 0.05 to 10 wt. %, based on prepolymer weight, of a hydrated compound which is stable up to at least about 100° C.; and heating the blended material to a selected foaming temperature of from about 120° C. to about 320° C. for a period of from about 10 to about 60 minutes.
Claim 3
Dependent Claim
88 words
A foamable material capable of expanding into a low density, resilient, flame resistant modified polyimide foam product, obtained according to the following method: reacting an aromatic dianhydride with an effective amount of an oxoimine having the general formula ##STR9## where "x" is an integer from 1 to 5, in a mole ratio of oxime to dianhydride up to about 1.5:1 to produce an N-substituted aliphatic imide; dissolving said imide in a reactive solvent esterfying agent to esterify said imide; adding thereto a diamine; and drying the resulting solution.
Claim 4
Dependent Claim
88 words
A foamable material capable of expanding into a low density, resilient, flame resistant modified polyimide foam product, obtained according to the following method: reacting an aromatic dianhydride with an effective amount of an oxoimine having the general formula ##STR9## where "x" is an integer from 1 to 5, in a mole ratio of oxime to dianhydride up to about 1.5:1 to produce an N-substituted aliphatic imide; dissolving said imide in a reactive solvent esterfying agent to esterify said imide; adding thereto a diamine; and drying the resulting solution.
Claim 5
Dependent Claim
40 words
The product of claim 2 further including the step of: blending with the powdered prepolymer from about 0.05 to 10 wt. % based on prepolymer weight, of a hydrated compound which is stable up to at least about 100° C.
References Cited (Backward Citations)
US4426463A
Cited
US4425441A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |