US3639656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formation of polyphenylene ethers
Assignee: General Electric Co
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Filing: 1969-03-13
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Granted: 1972-02-01
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Expires: 1989-03-13
Abstract
Abstract A PROCESS FOR THE FORMATION OF HIGH MOLECULAR WEIGHT POLYPHENYLENE ETHERS BY THE OXIDATIVE COUPLING OF A PHENOLIC PRECURSOR IN THE PRESENCE OF A CATALYST COMPRISING AN ANHYDROUS NON-BASIC CUPRIC SALT AND A PRIMARY OR SECONDARY AMINE. THE PROCESS IS CHARACTERIZED BY THE CHOICE OF CATALYST WHICH PROVIDES HIGH MOLECULAR WEIGHT POLYMER IN A GIVEN REACTION TIME OR SUBSTANTIALLY DECREASED REACTION TIME.
Inventors
- 👤 James G Bennett
- 👤 Glenn D Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:17
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34; C08G65/38; C08G65/44
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |