US3073801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing polyethylene terephthalate
Assignee: Glanzstoff AG
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Filing: 1959-04-29
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Granted: 1963-01-15
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Expires: 1979-04-29
Abstract
No abstract record available.
Inventors
- 👤 Siggel Erhard
- 👤 Riehl Lothar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:34
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/85; C08G63/86; C08G63/866
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
139 words
IN A METHOD OF PREPARING POLYETHYLENE TEREPHTHALATE WHEREIN DIMETHYL TEREPTHALATE IS REACTED WITH ETHYLENE GLYCOL IN THE PRESENCE OF AN ESTER INTERCHANGE CATALYST TO FORM THE DIGLYCOL ESTER OF TEREPHTHALIC ACID AND WHEREIN THE DIGLYCOL ESTER OF TEREPHTHALIC ACID SUBSEQUENTLY IS POLYMERIZED IN THE PRESENCE OF A POLYCONDENSATION CATALYST, THE IMPROVEMENT WHICH COMPRISES: INCORPORATING IN THE REACTION MIXTURE AS THE POLYCONDENSATION CATALYST FOR THE POLYMERIZATION OF THE DIGLYCOL ESTER OF TEREPHTHALIC ACID FROM ABOUT 0.01 TO ABOUT 0.1% BY WEIGHT BASED ON THE WEIGHT OF SAID DIMETHYL TEREPHTATHALATE OF AN INSOLUBLE ORTHO-ANTIMONATE HAVING THE FORMULA XZY (SBO4)2 WHEREIN X, Y, AND Z ARE METALS SELECTED FROM THE GROUP CONSISTING OF BERYLLIUM, MAGNESIUM, CALCIUM, ZINC, STRONTIUM, CADMIUM, AND BARIUM; AND THEREAFTER MAINTAINING THE REACTION MIXTURE AT A SUITABLE TEMPERATURE TO EFFECT THE POLYMERIZATION OF SAID DIGLYCOL ESTER OF TERPTHALIC ACID.
Claim 2
Dependent Claim
139 words
IN A METHOD OF PREPARING POLYETHYLENE TEREPHTHALATE WHEREIN DIMETHYL TEREPTHALATE IS REACTED WITH ETHYLENE GLYCOL IN THE PRESENCE OF AN ESTER INTERCHANGE CATALYST TO FORM THE DIGLYCOL ESTER OF TEREPHTHALIC ACID AND WHEREIN THE DIGLYCOL ESTER OF TEREPHTHALIC ACID SUBSEQUENTLY IS POLYMERIZED IN THE PRESENCE OF A POLYCONDENSATION CATALYST, THE IMPROVEMENT WHICH COMPRISES: INCORPORATING IN THE REACTION MIXTURE AS THE POLYCONDENSATION CATALYST FOR THE POLYMERIZATION OF THE DIGLYCOL ESTER OF TEREPHTHALIC ACID FROM ABOUT 0.01 TO ABOUT 0.1% BY WEIGHT BASED ON THE WEIGHT OF SAID DIMETHYL TEREPHTATHALATE OF AN INSOLUBLE ORTHO-ANTIMONATE HAVING THE FORMULA XZY (SBO4)2 WHEREIN X, Y, AND Z ARE METALS SELECTED FROM THE GROUP CONSISTING OF BERYLLIUM, MAGNESIUM, CALCIUM, ZINC, STRONTIUM, CADMIUM, AND BARIUM; AND THEREAFTER MAINTAINING THE REACTION MIXTURE AT A SUITABLE TEMPERATURE TO EFFECT THE POLYMERIZATION OF SAID DIGLYCOL ESTER OF TERPTHALIC ACID.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-01-14 | 1966-07-16 | 1967-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-01-14 | 1970-07-16 | 1971-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-01-14 | 1974-07-16 | 1975-01-15 | $7700.00 | Window Closed / Lapsed |