US4089906A
Expired / Lapsed
US
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Method for the preparation of polythioethers from thiodiethanol using acidic carbon
Assignee: Wyeth Holdings LLC
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Filing: 1976-10-27
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Granted: 1978-05-16
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Expires: 1996-10-27
Abstract
Abstract Preparation of polythioethers by the polycondensation of thiodiethanol in the presence of an acid-acting carbon.
Inventors
- 👤 Ajaib Singh
- 👤 Joseph Lawrence Schmitt, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:02
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
144 words
A method for the preparation of polycondensation oligomers of thiodiethanol with a molecular weight of about 300 to 5,300 which comprises condensing thiodiethanol or a mixture of a major proportion of thiodiethanol and one or more aliphatic diols at a temperature ranging from above about 150° C to 210° C in the presence of from about 0.5 to 20 percent by weight of an acid-acting carbon catalyst consisting essentially of acidic activated carbon and acidic activated charcoal, the acidity thereof being due to acidic sites on the catalyst surface, said catalyst being such that the pH of an aqueous slurry of a 5 gram portion of the catalyst in 50 ml. of water after stirring for 5 minutes is the same or lower than the pH of a 1 gram portion of the catalyst in 50 ml. of water after stirring for 5 minutes.
Claim 2
Independent Claim
144 words
A method for the preparation of polycondensation oligomers of thiodiethanol with a molecular weight of about 300 to 5,300 which comprises condensing thiodiethanol or a mixture of a major proportion of thiodiethanol and one or more aliphatic diols at a temperature ranging from above about 150° C to 210° C in the presence of from about 0.5 to 20 percent by weight of an acid-acting carbon catalyst consisting essentially of acidic activated carbon and acidic activated charcoal, the acidity thereof being due to acidic sites on the catalyst surface, said catalyst being such that the pH of an aqueous slurry of a 5 gram portion of the catalyst in 50 ml. of water after stirring for 5 minutes is the same or lower than the pH of a 1 gram portion of the catalyst in 50 ml. of water after stirring for 5 minutes.
Claim 3
Dependent Claim
21 words
A method according to claim 1 wherein said catalyst is present in an amount of about 1 to 5% by weight.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein said catalyst is acidic activated carbon.
Claim 5
Dependent Claim
13 words
A method according to claim 1 wherein said catalyst is acidic activated charcoal.
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) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |