US3740267A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cleaning apparatus used in processing polyethylene terephthalate
Assignee: Honeywell International Inc
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Filing: 1971-09-22
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Granted: 1973-06-19
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Expires: 1991-09-22
Abstract
Abstract METHOD OF REMOVING UNWANTED RESIDUES OF POLYETHYLENE TEREPHTHALATE FROM APPARATUS USED IN PROCESSING POLYETHYLENE TEREPHTHALATE WHICH INVOLVES WASHING THE APPARATUS WITH A CLEANING SOLVENT COMPRISING TRIETHANOLAMINE AT A TEMPERATURE OF 150*-260*C. TO FORM A SOLUTION OF SUBSTANTIALLY ALL OF THEPOLYETHYLENE TEREPHTHALATE REMAINING IN THE APPARATUS. THE CLEANING PROCESS CAN BE ACCELERATED BY THE ADDITION OF A MINOR PROPORTION OF ALKALI METAL HYDROXIDE TO THE SOLVENT.
Inventors
- 👤 J Haylock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:51
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/008
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |