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US4306058A
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Method for reducing oligomeric cyclic ether content of a polymerizate
Assignee: EIDP Inc
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Filing: 1980-11-19
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Granted: 1981-12-15
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Expires: 2000-11-19
Abstract
Abstract The oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide- or a tetrahydrofuran/alkylene oxide polymerizate can be reduced by bringing the polymerizate into contact with a gas in the supercritical state.
Inventors
- 👤 Harry B. Copelin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:25
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/04; B01D11/0403; B01D11/0407; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4854; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/08; C08G65/16; C08G65/20; C08G65/30; C08G65/32; C08G65/329; C08G65/337; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/54
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
63 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide-, or a tetrahydrofuran/alkylene oxide polymerizate, the method comprising (a) bringing the polymerizate into contact with a gas in the supercritical state, for a time sufficient to reduce said ether content, the gas having a critical temperature of 0°-200° C., and then (b) separating the gas and the polymerizate.
Claim 2
Independent Claim
63 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide-, or a tetrahydrofuran/alkylene oxide polymerizate, the method comprising (a) bringing the polymerizate into contact with a gas in the supercritical state, for a time sufficient to reduce said ether content, the gas having a critical temperature of 0°-200° C., and then (b) separating the gas and the polymerizate.
Claim 3
Dependent Claim
17 words
The method of claim 1 in which the gas used has a critical temperature of 9°-155° C.
Claim 4
Dependent Claim
25 words
The method of claim 1 in which the gas is used at a temperature which is no more than 50° C. above its critical temperature.
Claim 5
Dependent Claim
25 words
The method of claim 1 in which the gas is used at a temperature which is no more than 20° C. above its critical temperature.
Claim 6
Dependent Claim
26 words
The method of claim 1 in which the gas is a saturated- or monoethylenically unsaturated hydrocarbon, a halogenated hydrocarbon, carbon dioxide, dimethyl ether or diethyl ether.
Claim 7
Dependent Claim
13 words
The method of claim 5 in which the gas is ethylene or propylene.
Claim 8
Dependent Claim
49 words
A method for separating a tetrahydrofuran-, an alkylene oxide- or a tetrahydrofuran/alkylene oxide polymerizate and oligomeric cyclic ethers contained therein, the method comprising removing ethers from the polymerizate according to the method of claim 1, then releasing the gas from the supercritical state and collecting the thus separated ethers.
Claim 9
Independent Claim
49 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/ethylene oxide- or a tetrahydrofuran/propylene oxide polymerizate, the method comprising bringing the polymerizate into contact with propylene in the supercritical state, for a time sufficient to reduce the ether content, and then separating the propylene and the polymerizate.
Claim 10
Independent Claim
49 words
A method for reducing the oligomeric cyclic ether content of a tetrahydrofuran/ethylene oxide- or a tetrahydrofuran/propylene oxide polymerizate, the method comprising bringing the polymerizate into contact with propylene in the supercritical state, for a time sufficient to reduce the ether content, and then separating the propylene and the polymerizate.
Claim 11
Independent Claim
18 words
The method of claims 1, 2 or 3-8 in which the gas or the polymerizate contains an entrainer.
Claim 12
Dependent Claim
11 words
The method of claim 9 in which the entrainer is toluene.
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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |