US4464520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Delayed cure bismaleimide resins
Assignee: United States Department of Energy
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Filing: 1982-08-12
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Granted: 1984-08-07
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Expires: 2002-08-12
Abstract
Abstract Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R 1 and R 2 each independently is H, C 1-4 -alkyl, C 1-4 -alkoxy, Cl or Br, or R 1 and R 2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R 1 and R 2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH 2 ) n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.
Inventors
- 👤 Johnnie E. Adams
- 👤 Donald R. Jamieson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:22
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/125; C08F; C08F22/00; C08F22/36; C08F22/40; C08G73/123; C08G73/124
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
153 words
A method for delayed curing of a bismaleimide, comprising: heating the bismaleimide to a temperature equal to or greater than its melting point but lower than the temperature at which it begins to polymerize; holding the melted bismaleimide at a temperature lower than that at which it begins to polymerize for a period of time sufficient to obtain a homogeneous melt; and then heating the bismaleimide to the temperature at which it polymerizes; said bismaleimide having the formula ##STR4## wherein R 1 and R 2 each independently is H, C 1-4 -alkyl, C 1-4 -alkoxy, Cl or Br, or R 1 and R 2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R 1 and R 2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH 2 ) n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.
Claim 2
Independent Claim
153 words
A method for delayed curing of a bismaleimide, comprising: heating the bismaleimide to a temperature equal to or greater than its melting point but lower than the temperature at which it begins to polymerize; holding the melted bismaleimide at a temperature lower than that at which it begins to polymerize for a period of time sufficient to obtain a homogeneous melt; and then heating the bismaleimide to the temperature at which it polymerizes; said bismaleimide having the formula ##STR4## wherein R 1 and R 2 each independently is H, C 1-4 -alkyl, C 1-4 -alkoxy, Cl or Br, or R 1 and R 2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R 1 and R 2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH 2 ) n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein the bismaleimide is 1,2-bis(2-maleimidophenylthio)ethane.
Claim 4
Dependent Claim
10 words
A polybismaleimide prepared according to the process of claim 1.
Claim 5
Dependent Claim
16 words
An oxygen and heat resistant composite in which the matrix is the polybismaleimide of claim 3.
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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) | 1987-08-07 | 1988-02-06 | 1988-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-07 | 1992-02-06 | 1992-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-07 | 1996-02-06 | 1996-08-07 | $7700.00 | Window Closed / Lapsed |