Patent US5420232A successfully refreshed from Google Patents.
US5420232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making polyamic esters
Assignee: International Business Machines Corp
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Filing: 1992-04-29
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Granted: 1995-05-30
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Expires: 2012-04-29
Abstract
Abstract The present invention relates to an improved process for making polyamic ester comprising reacting an aromatic diester diacid halide with the monohydrohalide salt of an aromatic diamine in the presence of a base. The polyamic ester can be imidized to form a polyimide suitable for use in electronic components.
Inventors
- 👤 Daniel J. Dawson
- 👤 Richard A. DiPietro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:50
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
27 words
A process for making polyamic ester comprising reacting an aromatic diester diacid halide with the monohydrohalide salt of phenylene diamine in the presence of a amine base.
Claim 2
Dependent Claim
27 words
A process for making polyamic ester comprising reacting an aromatic diester diacid halide with the monohydrohalide salt of phenylene diamine in the presence of a amine base.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein the aromatic diester diacid chloride is diethyl pyromellitate diacid chloride, diethyl biphenyltetracarboxylate diacid chloride, dimethyl biphenyltetracarboxylate diacid chloride, or di(methacryloxyethyl) biphenyltetracarboxylate diacid chloride.
References Cited (Backward Citations)
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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) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |