Patent US3573254A successfully refreshed from Google Patents.
US3573254A
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US
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Reductive capping of poly(phenylene oxides)
Assignee: General Electric Co
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Filing: 1968-12-23
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Granted: 1971-03-30
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Expires: 1988-12-23
Abstract
Abstract POLY (PHENYLENE OXIDES) HAVING IMPROVED OPTICAL CLARITY ARE PREPARED BY TREATING A SOLUTION OF THE POLYMER WITH ALUMINUM, CADMIUM, MAGESIUM, TIN OR ZINC, PRIOR TO OR SIMULTANEOUSLY WITH THE CAPPING REACTION, WHEREBY THE HYDROXYL GROUPS OF THE POLYMER ARE CONVERTED TO SUBSTITUENTS WHICH ARE SUBSTANTIALLY INERT TO OXYGEN ATTACK AT ELEVATED TEMPERATURES. STILL FURTHER IMPROVEMENT IN CLARITY IS OBTAINED WHEN A CARBOXYLIC ACID SOLUBLE IN THE REACTION MIXTURE IS USED IN CONJUNCTION WITH ZINC AND ESPECIALLY, WHEN THIS TREATMENT IS CARRIED OUT SIMULTANEOUSLY WITH A HOT-CAPPING PROCESS, WHICH GENERATES AND CAPS ANY INCIPIENT HYDROXYL GROUPS ON THE POLYMER CHAIN.
Inventors
- 👤 Arnold Factor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:37
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34; C08G65/46; C08G65/48; C08G65/485; Y; Y10; Y10S; Y10S525/00; Y10S525/905
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) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |