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Patent US4945170A successfully refreshed from Google Patents.
US4945170A
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Method for making polyimides and products produced thereby
Assignee: Wyeth Holdings LLC
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Filing: 1986-05-30
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Granted: 1990-07-31
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Expires: 2006-05-30
Abstract
Abstract A method for making polyimide polymers is provided by effecting reaction between an aliphatically unsaturated imide, such as maleimide, formaldehyde, and an organic polyamine, for example trimethylene bis(4-aminobenzoate), for example in refluxing ethanol. The polyimides produced by the simple one-step method are pure, and exhibit superior toughness, and reduced shrinkage upon cure by heating. The new product are useful as molding compounds, laminating resins, and the like, being especially suitable for airplane parts, advanced composites, high performance adhesives and printed circuit boards.
Inventors
- 👤 Dalip K. Kohli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:09
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/26; C08G12/34; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/121
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A method for the preparation of a bismaleimide of the formula: ##STR20## which comprises heating a mixture comprising (i) maleimide, a compound of the formula ##STR21## (ii) from about 0.5 to about 2 moles per mole of (i) of formaldehyde; and (iii) from about 0.5 to 2 moles per mole of (i) of an arylene diamine of the formula ##STR22## until reaction is substantially complete.
Claim 2
Independent Claim
65 words
A method for the preparation of a bismaleimide of the formula: ##STR20## which comprises heating a mixture comprising (i) maleimide, a compound of the formula ##STR21## (ii) from about 0.5 to about 2 moles per mole of (i) of formaldehyde; and (iii) from about 0.5 to 2 moles per mole of (i) of an arylene diamine of the formula ##STR22## until reaction is substantially complete.
References Cited (Backward Citations)
US3625912A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |