US3305495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the continuous re-use of polyethylene terephthalate waste
Assignee: Hoechst AG
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Filing: 1963-09-20
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Granted: 1967-02-21
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Expires: 1983-09-20
Abstract
No abstract record available.
Inventors
- 👤 Orde Hans-Otto Vom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:35
CPC Classifications
C; C08; C08J; C08J11/00; C08G; C08G63/00; C08G63/78; C08G63/785; C08J2367/00; C08J2367/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PROCESS FOR THE PRODUCTION OF HIGH MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE UTILIZING WASTE POLYETHYLENE TEREPHTHALATE WHCIH COMPRISES (A) FORMING A MELT OF A LOW MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE PRECONDENSATE AND HIGH MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE WASTE, SAID MIXTURE HAVING A VISCOSITY NUMBER OF GREATER THAN 0.03, SAID WASTE HAVING A VISCOSITY NUMBER BETWEEN 0.08 AND 0.088 AND SAID PRECONDENSATE HAVING A VISCOSITY NUMBER BETWEEN 0.01 AND 0.012 AND (B) POLYCONDENSING SAID MIXTURE AT A TEMPERATURE BETWEEN 305 AND 315*C. BY FALLING-FILM EVAPORATION IN A FIRST ZONE AT A PRESSURE OF FROM 25 TO 18 MM. MERCURY AND THEREAFTER IN A SECOND ZONE AT A PRESSURE LESS THAN 0.5 MM. MERCURY.
Claim 2
Dependent Claim
110 words
A PROCESS FOR THE PRODUCTION OF HIGH MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE UTILIZING WASTE POLYETHYLENE TEREPHTHALATE WHCIH COMPRISES (A) FORMING A MELT OF A LOW MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE PRECONDENSATE AND HIGH MOLECULAR WEIGHT POLYETHYLENE TEREPHTHALATE WASTE, SAID MIXTURE HAVING A VISCOSITY NUMBER OF GREATER THAN 0.03, SAID WASTE HAVING A VISCOSITY NUMBER BETWEEN 0.08 AND 0.088 AND SAID PRECONDENSATE HAVING A VISCOSITY NUMBER BETWEEN 0.01 AND 0.012 AND (B) POLYCONDENSING SAID MIXTURE AT A TEMPERATURE BETWEEN 305 AND 315*C. BY FALLING-FILM EVAPORATION IN A FIRST ZONE AT A PRESSURE OF FROM 25 TO 18 MM. MERCURY AND THEREAFTER IN A SECOND ZONE AT A PRESSURE LESS THAN 0.5 MM. MERCURY.
References Cited (Backward Citations)
GB905562A
Cited
US3250747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |