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Patent US4202964A successfully refreshed from Google Patents.
US4202964A
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Method for reducing oligomeric cyclic ether content of a polymerizate
Assignee: EIDP Inc
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Filing: 1978-11-27
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Granted: 1980-05-13
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Expires: 1998-11-27
Abstract
Abstract The oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate is significantly reduced by bringing the polymerizate into contact at elevated temperatures with an ion exchange resin bearing -SO 3 H groups.
Inventors
- 👤 Gerfried Pruckmayr
- 👤 Ivan M. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:03
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/16; C08G65/20; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4854; C08G65/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
67 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate, the method comprising bringing the polymerizate into contact, at a temperature of 60°-150° C., with 0.5-25% , by weight of the polymerizate, of a cationic ion exchange resin bearing --SO 3 H groups, insoluble in the reaction medium, for a time sufficient to significantly reduce the oligomeric cyclic ether content of the polymerizate.
Claim 2
Independent Claim
67 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate, the method comprising bringing the polymerizate into contact, at a temperature of 60°-150° C., with 0.5-25% , by weight of the polymerizate, of a cationic ion exchange resin bearing --SO 3 H groups, insoluble in the reaction medium, for a time sufficient to significantly reduce the oligomeric cyclic ether content of the polymerizate.
Claim 3
Dependent Claim
14 words
The method of claim 1 conducted while byproducts are withdrawn from the reaction zone.
Claim 4
Dependent Claim
72 words
The method of claim 1 wherein the ion exchange resin is a macroreticular resin having a backbone which is crosslinked copolymer of styrene and divinyl benzene and an initial hydrogen ion concentration of about 4.9 milliequivalents per gram (dry), an initial surface area of about 40-50 square meters per gram, an initial porosity of 0.3-0.35 milliliter of pore per milliliter of bead, and an initial average pore diameter of 200-600 Angstrom units.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the ion exchange resin is a copolymer of tetrafluoroethylene and a monomer represented by the structure ##STR3## hydrolyzed to the acid form.
Claim 6
Dependent Claim
12 words
The method of claim 1 run at a temperature of 90°-110° C.
Claim 7
Dependent Claim
19 words
The method of claim 1 wherein the concentration of ion exchange resin is 3-7%, by weight of the polymerizate.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein the polymerizate is of a tetrahydrofuran/ethylene oxide copolymer.
Claim 9
Dependent Claim
52 words
The method of claim 1 wherein the polymerizate is of a tetrahydrofuran/ethylene oxide copolymer, the ion exchange resin is the resin of claim 3 at a concentration of 3-7%, by weight of the polymerizate, byproducts are withdrawn from the reaction zone and the method is run at a temperature of 90°-110° 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) | 1983-05-13 | 1983-11-12 | 1984-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-13 | 1987-11-12 | 1988-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-13 | 1991-11-12 | 1992-05-13 | $7700.00 | Window Closed / Lapsed |