Patent US3674747A successfully refreshed from Google Patents.
US3674747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of high molecular weight linear polyesters
Assignee: Bayer AG
•
Filing: 1969-12-17
•
Granted: 1972-07-04
•
Expires: 1989-12-17
Abstract
Abstract A process for the production of high molecular linear polyesters by polycondensing a glycol with terephthalic acid or a terephthalic acid ester in the presence of a polycondensation catalyst. The condensation catalyst is a titanium-dioxide containing 0.01 to 20% by weight of a metal compound, preferably germanium dioxide and antimonium oxide is used as a metal compound. The catalyst can be prepared by calcinating titanium dioxide together with the metal compound.
Inventors
- 👤 Robert Schnegg
- 👤 Herbert Pelousek
- 👤 Robert Dippolhofer
- 👤 Wolfgang Wiegreffe
- 👤 Hans-Georg Voelz
- 👤 Gerhard Kienast
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:15
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
14 words
The process as claimed in claim 1, wherein said metal compound is germanium dioxide.
Claim 2
Dependent Claim
14 words
The process as claimed in claim 1, wherein said metal compound is zinc phosphate.
Claim 3
Dependent Claim
15 words
The process as claimed in claim 1, wherein said metal compound is an antimony oxide.
Claim 4
Dependent Claim
20 words
The process as claimed in claim 1, wherein said catalyst is a titanium dioxide calcined together with the metal compound.
Claim 5
Dependent Claim
33 words
The process of claim 1 in which the metal compOund is an oxide and the metal compound is present in an amount of 0.1 to 5% by weight based on the titanium dioxide.
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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |