Patent US4510333A successfully refreshed from Google Patents.
US4510333A
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Method for preparing poly(tetramethylene ether) glycol having narrow molecular weight distribution
Assignee: EIDP Inc
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Filing: 1984-06-05
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Granted: 1985-04-09
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Expires: 2004-06-05
Abstract
Abstract In the preparation of poly(tetramethylene ether) glycol by the polymerization of tetrahydrofuran (THF) using a cationic initiator, molecular weight distribution (MWD) can be held within narrow limits by bringing the THF and the initiator together in a mol ratio such that the degree of polymerization will be at about a minimum and at a temperature which will promote about a maximum number of tertiary oxonium ions, then quickly cooling the reaction mass to -25° C. to +25° C., and then adding enough THF to complete the polymerization. When the desired molecular weight and MWD have been reached, the polymerization is quenched and the polymer isolated.
Inventors
- 👤 Gerfried Pruckmayr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:08
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/16; C08G65/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
A method for preparing poly(tetramethylene ether)glycol having a molecular weight distribution of 1.1-1.4, the method comprising (a) bringing tetrahydrofuran and a cationic initiator together (1) in a mol ratio such that the degree of polymerization will be at about a minimum, and (2) at a temperature which will promote generation of about a maximum number of tertiary oxonium ions; (b) keeping the resulting mixture at the temperature in (a 2) until the tertiary oxonium ion concentration is at or near a maximum, and then cooling the reaction mass in (a) to within the range -25° C. through +25° C.; (c) then adding enough THF to the reaction mass to allow the polymerization to proceed to the desired point; (d) then holding the reaction mass within the range -25° C. through +25° C. until the desired molecular weight and MWD have been reached; and then (e) quenching the polymerization.
Claim 2
Independent Claim
148 words
A method for preparing poly(tetramethylene ether)glycol having a molecular weight distribution of 1.1-1.4, the method comprising (a) bringing tetrahydrofuran and a cationic initiator together (1) in a mol ratio such that the degree of polymerization will be at about a minimum, and (2) at a temperature which will promote generation of about a maximum number of tertiary oxonium ions; (b) keeping the resulting mixture at the temperature in (a 2) until the tertiary oxonium ion concentration is at or near a maximum, and then cooling the reaction mass in (a) to within the range -25° C. through +25° C.; (c) then adding enough THF to the reaction mass to allow the polymerization to proceed to the desired point; (d) then holding the reaction mass within the range -25° C. through +25° C. until the desired molecular weight and MWD have been reached; and then (e) quenching the polymerization.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the cationic initiator is fluosulfonic acid.
Claim 4
Dependent Claim
16 words
The method of claim 2 wherein the tetrahydrofuran/fluosulfonic acid mol ratio in (a 1) is 4/1-1/1.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein the temperature in (a 2) is 20°-80° C.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein the temperature is (a 2) is 40°-60° C. and the mol ratio in (a 1) is 2/1.
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) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |