US3585259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacturing friable solid polyester products
Assignee: Eastman Kodak Co
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Filing: 1969-08-15
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Granted: 1971-06-15
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Expires: 1989-08-15
Abstract
Abstract IT HAS BEEN FOUND THAT BY (A) INCORPORATING AN INERT GAS INTO MOLTEN POLYESTER PREPOLYMER PRIOR TO THE TIME THE PREPOLYMER IS SOLIDIFIED (AFTER WHICH IT IS TO BE GROUND AND SUBJECTED TO A FURTHER POLYMERIZATION STEP VIA A SOLID STATE REACTION) AND (B) MAINTAINING THE GAS DISPERSED THROUGH THE PREPOLYMER AS IT IS SOLIDIFIED, MAKES IT POSSIBLE TO ECONOMICALLY GRIND SOLIDIFIED PREPOLYMERIC MATERIAL HAVING SIGNIFICANTLY HIGHER INTRINSIC VISCOSITIES THAN WAS HERETOFORE BELIEVED POSSIBLE. THE USE OF PREPOLYMER HAVING HIGHER I.V.''S SIMLIFIES THE SUBSEQUENT POLYMERIZATION STEP.
Inventors
- 👤 Edwin B Lefferts
- 👤 Kenneth T Barkey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:26
CPC Classifications
B; B29; B29B; B29B13/00; B29B13/10; C; C08; C08G; C08G63/00; C08G63/78; C08G63/80
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) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |