US3980672A
Expired / Lapsed
US
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Method of manufacturing fungible polytetramethylene ether glycol
Assignee: Qo Chemicals Inc
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Filing: 1975-07-23
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Granted: 1976-09-14
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Expires: 1995-07-23
Abstract
Abstract Disclosed herein is a method which provides substantially zero acid number polytetramethylene ether glycol thus making it possible to regard polytetramethylene ether glycol as a fungible commodity. The improvement is achieved by complete removal of a trace impurity, believed to be n-butyl aldehyde, from dry tetrahydrofuran, by contact with molecular sieves of a particular definition, prior to the polymerization of the tetrahydrofuran in the production of polytetramethylene ether glycol.
Inventors
- 👤 Hideo Tomomatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:25
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08; C08; C08G; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/16; C08G65/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
A method of purifying tetrahydrofuran comprising contacting liquid tetrahydrofuran containing n-butyl aldehyde and having a water content of less than 0.5 percent, with a molecular sieve having a nominal pore size in the range of about 4-5 Angstroms inclusive, and having a water heat of adsorption of about 1800 ± 100 btu/pound H 2 O, continuing said contacting until said n-butyl aldehyde is completely removed from the liquid tetrahydrofuran, and separating liquid tetrahydrofuran from the molecular sieve.
Claim 2
Independent Claim
77 words
A method of purifying tetrahydrofuran comprising contacting liquid tetrahydrofuran containing n-butyl aldehyde and having a water content of less than 0.5 percent, with a molecular sieve having a nominal pore size in the range of about 4-5 Angstroms inclusive, and having a water heat of adsorption of about 1800 ± 100 btu/pound H 2 O, continuing said contacting until said n-butyl aldehyde is completely removed from the liquid tetrahydrofuran, and separating liquid tetrahydrofuran from the molecular sieve.
Claim 3
Independent Claim
117 words
A method of purifying tetrahydrofuran comprising contacting tetrahydrofuran containing n-butyl aldehyde and having a water content of less than 0.5 percent w/w with molecular sieve having a nominal pore size in the range of about 4-5 Angstroms inclusive and having a water heat of adsorption of about 1800 btu/pound H 2 O ± 100 btu/pound H 2 O wherein the molecular sieve is a crystalline zeolite selected from the group sodium and calcium alumino-silicates, and mixtures thereof, and wherein the tetrahydrofuran is contacted in a liquid phase with a solid molecular sieve material, and said contacting is continued until said n-butyl aldehyde is completely removed from the liquid tetrahydrofuran, and separating the tetrahydrofuran from the molecular sieve.
Claim 4
Independent Claim
117 words
A method of purifying tetrahydrofuran comprising contacting tetrahydrofuran containing n-butyl aldehyde and having a water content of less than 0.5 percent w/w with molecular sieve having a nominal pore size in the range of about 4-5 Angstroms inclusive and having a water heat of adsorption of about 1800 btu/pound H 2 O ± 100 btu/pound H 2 O wherein the molecular sieve is a crystalline zeolite selected from the group sodium and calcium alumino-silicates, and mixtures thereof, and wherein the tetrahydrofuran is contacted in a liquid phase with a solid molecular sieve material, and said contacting is continued until said n-butyl aldehyde is completely removed from the liquid tetrahydrofuran, and separating the tetrahydrofuran from the molecular sieve.
References Cited (Backward Citations)
US2818449A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |