US4192943A
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Method for reducing oligomeric cyclic ether content of a polymerizate
Assignee: EIDP Inc
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Filing: 1978-12-21
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Granted: 1980-03-11
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Expires: 1998-12-21
Abstract
Abstract The oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate is significantly reduced by bringing the polymerizate into contact with an acid-activated sodium or calcium montmorillonite clay.
Inventors
- 👤 Ivan M. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:50
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/16; C08G65/20; C08G65/30; C08G2650/00; C08G2650/02; C08G2650/12; C08G2650/28; C08G2650/34
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
60 words
A method for reducing the oligomeric cyclic ether content of a substantially monomer-free THF/alkylene oxide polymerizate, the method comprising bringing the polymerizate into contact, at a temperature of 70°-150° C., with 1-50%, by weight of the polymerizate, of an acid-activated sodium or calcium montmorillonite clay, for a time sufficient to significantly reduce the oligomeric cyclic ether content of the polymerizate.
Claim 2
Independent Claim
60 words
A method for reducing the oligomeric cyclic ether content of a substantially monomer-free THF/alkylene oxide polymerizate, the method comprising bringing the polymerizate into contact, at a temperature of 70°-150° C., with 1-50%, by weight of the polymerizate, of an acid-activated sodium or calcium montmorillonite clay, for a time sufficient to significantly reduce the oligomeric cyclic ether content of the polymerizate.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the clay is an acid-activated Wyoming bentonite.
Claim 4
Dependent Claim
12 words
The method of claim 1 run at a temperature of 80°-120° C.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the concentration of the clay is 3-10% by weight of the polymerizate.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the polymerizate is of THF and ethylene oxide.
Claim 7
Dependent Claim
42 words
The method of claim 1 wherein the polymerizate is of THF and ethylene oxide, the clay is an acid-activated Wyoming bentonite at a concentration of 3-10%, by weight of the polymerizate, and the method is run at a temperature of 80°-120° C.
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) | 1983-03-11 | 1983-09-10 | 1984-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-11 | 1987-09-10 | 1988-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-11 | 1991-09-10 | 1992-03-11 | $7700.00 | Window Closed / Lapsed |