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US3875208A
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Meta-and para-phenylene-bis-(4-hydroxymethylene-phthalic acids and the diester and tetraester thereof
Assignee: IFP Energies nouvelles
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Filing: 1973-08-31
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Granted: 1975-04-01
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Expires: 1993-08-31
Abstract
Abstract M- OR P-Phenylene-bis-(4-hydroxymethylenephthalic acid, and the diester and tetraester thereof useful as intermediates to prepare soluble, high molecular weight, carbinol-containing polyimides.
Inventors
- 👤 Choua Cohen
- 👤 Pierre Giuliani
- 👤 Bernard Sillion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:42
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C07; C07C; C07C65/00; C07C65/01; C07C65/105; C07C65/32; C07C65/34; C07C65/36
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
7 words
META-PHENYLENE BIS(4-HYDROXYMETHYLENE PHTHALIC ACID) OF THE FORMULA
Claim 2
Dependent Claim
7 words
META-PHENYLENE BIS(4-HYDROXYMETHYLENE PHTHALIC ACID) OF THE FORMULA
Claim 3
Dependent Claim
10 words
An ester of meta-phenylene bis(4-hydroxymethylene phthalic acid) of the formula
Claim 4
Dependent Claim
10 words
An ester of meta-phenylene bis(4-hydroxymethylene phthalic acid) of the formula
References Cited (Backward Citations)
DE2005587A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |