US4769197A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for molding precured high temperature resins
Assignee: RTX Corp
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Filing: 1987-02-02
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Granted: 1988-09-06
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Expires: 2007-02-02
Abstract
Abstract A method for molding composite prepregs using high temperature substantially cured thermosetting resins that reduces fiber damage. Fiber plies are impregnated with solutions of high temperature substantially cured thermosetting resins and the plies are stacked to form a prepreg. A solid flowable particulate silicone rubber is caused to apply pressure to the prepreg to form a composite. This invention makes a significant advance in the field of molding high temperature resin composites by providing methods of molding that reduce fiber damage, shorten molding time and result in denser parts.
Inventors
- 👤 Robert V. Kromrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:26
CPC Classifications
B; B29; B29B; B29B15/00; B29B15/08; B29B15/10; B29B15/12; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/44; B29C43/00; B29C43/02; B29C43/10; C; C08; C08J; C08J5/00; C08J5/24; B29C43/12; B29C43/32; B29C43/52; B29K; B29K2079/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
63 words
A method for molding composite prepregs comprising (a) impregnating fiber plies with a solvent solution of a high temperature substantially cured thermosetting resin; (b) stacking said impregnated plies to form a composite prepreg; and (c) causing a solid flowable particulate silicone polymer to apply a substantially uniform pressure to said composite prepreg to form a composite; wherein said composite has reduced fiber damage.
Claim 2
Independent Claim
63 words
A method for molding composite prepregs comprising (a) impregnating fiber plies with a solvent solution of a high temperature substantially cured thermosetting resin; (b) stacking said impregnated plies to form a composite prepreg; and (c) causing a solid flowable particulate silicone polymer to apply a substantially uniform pressure to said composite prepreg to form a composite; wherein said composite has reduced fiber damage.
Claim 3
Dependent Claim
18 words
The method as recited in claim 1 wherein said resin has a Tg greater than about 232° C.
Claim 4
Dependent Claim
16 words
The method as recited in claim 1 wherein said resin is a polybenzimidazole, polyphenyl-quinoxaline or bismaleimide.
Claim 5
Dependent Claim
18 words
The method as recited in claim 1 wherein said a solvent is dimethylacetamide, dimethylsulfoxide or normal methyl pyrrolidone.
Claim 6
Dependent Claim
20 words
The method as recited in claim 1 wherein said substantially cured thermosetting resin has less than about 5% volatile content.
Claim 7
Independent Claim
83 words
A method for molding composite prepregs comprising (a) impregnating fiber plies with a solution of high temperature substantially cured thermoplastic resin that: behaves as a thermosetting resin; can withstand high temperature use without melting; and tends to coalesce under high temperatures and pressures; (b) stacking said impregnated plies to form a composite prepreg; and (c) causing a solid flowable particulate silicone polymer to apply a substantially uniform pressure to said composite prepreg to form a composite; wherein said composite has reduced fiber damage.
Claim 8
Independent Claim
83 words
A method for molding composite prepregs comprising (a) impregnating fiber plies with a solution of high temperature substantially cured thermoplastic resin that: behaves as a thermosetting resin; can withstand high temperature use without melting; and tends to coalesce under high temperatures and pressures; (b) stacking said impregnated plies to form a composite prepreg; and (c) causing a solid flowable particulate silicone polymer to apply a substantially uniform pressure to said composite prepreg to form a composite; wherein said composite has reduced fiber damage.
Claim 9
Dependent Claim
14 words
The method as recited in claim 6 wherein said thermoplastic resin is a polyimide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |