US4090990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing polyformals in the presence of an organic epoxide
Assignee: Wyeth Holdings LLC
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Filing: 1976-12-20
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Granted: 1978-05-23
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Expires: 1996-12-20
Abstract
Abstract An improved process for preparing polyformals is provided which comprises condensing an aliphatic diol, in which the hydroxyl groups are separated by at least four carbon atoms, with an essentially stoichiometric amount of formaldehyde in the presence of a Bronsted acid catalyst and contacting the condensation product with an organic epoxide in an amount sufficient to react with the residue of said catalyst.
Inventors
- 👤 Ajaib Singh
- 👤 Samuel Kaizerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:16
CPC Classifications
C; C08; C08G; C08G4/00; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/56
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
In a process for preparing a polyformal which comprises condensing an aliphatic diol, in which the hydroxyl groups are separated by at least four carbon atoms, with an essentially stoichiometric amount of formaldehyde in the presence of a Bronsted acid catalyst, the improvement which comprises contacting the condensation product thus formed with an organic epoxide in an amount sufficient to react with the residue of said acid catalyst, whereby said acid residue is removed from said polyformal.
Claim 2
Dependent Claim
77 words
In a process for preparing a polyformal which comprises condensing an aliphatic diol, in which the hydroxyl groups are separated by at least four carbon atoms, with an essentially stoichiometric amount of formaldehyde in the presence of a Bronsted acid catalyst, the improvement which comprises contacting the condensation product thus formed with an organic epoxide in an amount sufficient to react with the residue of said acid catalyst, whereby said acid residue is removed from said polyformal.
Claim 3
Dependent Claim
12 words
The process according to claim 1 wherein the aliphatic diol is 1,6-hexanediol.
Claim 4
Dependent Claim
13 words
The process according to claim 1 wherein the acid catalyst is p-toluenesulfonic acid.
Claim 5
Dependent Claim
12 words
The process according to claim 1 wherein the organic epoxide is 3,4-epoxycyclohexanecarboxylate.
Claim 6
Dependent Claim
14 words
The process according to claim 1 wherein the organic epoxide is epoxidized soybean oil.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |