US3700639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystalline polystyrene products
Assignee: Atlantic Richfield Co
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Filing: 1971-12-22
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Granted: 1972-10-24
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Expires: 1991-12-22
Abstract
Abstract HIGHLY CRYSTALLINE, ISOTACTIC POLYSTYRENE PRODUCTS HAVING MOLECULAR WEIGHT OF LESS THAN 1,000,000 ARE PREPARED BY THE THERMAL DEGRADATION IN AIR AT TEMPERATURES BETWEEN 100*C. AND 260*C. OF HIGH MOLECULAR WEIGHT, HIGHLY CRYSTALLINE COPOLYMERS OF STYRENE WITH 2-20 PERCENT BY WEIGHT OF AN ALPHA-OLEFIN HAVING 3 TO 10 CARBON ATOMS. THE INITIAL COPOLYMERS HAVE A MOLECULAR WEIGHT IN EXCESS OF 1,000,000. THE RATE OF DEGRADATION OF THE COPOLYMERS OF THIS INVENTION IS GREATER THAN THE RATE OF DEGRADATION OF POLYSTYRENE AT THE SAME TEMPERATURES. THE CRYSTALLINITY OF THE RESULTING POLYSTYRENE PRODUCT IS GENERALLY HIGHER THAN THAT OF THE INITIAL COPOLYMERS.
Inventors
- 👤 George E Hulse
- 👤 James J Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:44
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08F8/00; C08F8/50; Y; Y10; Y10S; Y10S526/00; Y10S526/914
Claims Analysis
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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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |