US3767601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid phase polymerization of waste polyethylene terephthalate
Assignee: EIDP Inc
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Filing: 1971-09-01
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Granted: 1973-10-23
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Expires: 1991-09-01
Abstract
Abstract A SOLID PHASE PROCESS OF POLYMERIZING WASTE POLYETHYLENE TEREPHTHALATE (PET) BY CHARGING COMMINUTED WASTE PET TO A ROTARY KILN AND HEATING THE CHARGE IN AN ATMOSPHERE OF HOT, DRY, SCAVENGING GAS THEREBY INCREASING THE INTRINSIC VISCOSITY. PET POLYMERS HAVING INCREASED VISCOSITIES PROVIDE A POLYMER USEFUL IN MANUFACTURING DURABLE GOODS.
Inventors
- 👤 K Knox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:37
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/80; C08J; C08J11/00; C08J11/04; C08J2367/00; C08J2367/02; Y; Y02; Y02P; Y02P20/00; Y02P20/141; Y02P20/143; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 0
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |