Patent US2282092A successfully refreshed from Google Patents.
US4209641A
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US
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Process for the production of polytetramethylene ether glycol
Assignee: Mitsui Toatsu Chemicals Inc
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Filing: 1978-12-05
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Granted: 1980-06-24
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Expires: 1998-12-05
Abstract
Abstract An improved process for the production of polytetramethylene ether glycol is disclosed. Polytetramethylene ether glycol is obtained with a high yield by subjecting tetrahydrofuran to ring opening polymerization in the presence or absence of an organic solvent with the use of, as a catalyst, a lithium halide in conjunction with fuming sulfuric acid. Average molecular weight of the glycol product can be controlled in the range of 1000-3000 at will by varying the amounts of the lithium halide and fuming sulfuric acid used.
Inventors
- 👤 Takayoshi Masuda
- 👤 Tsutomu Takase
- 👤 Yoshimoto Watanabe
- 👤 Fumio Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:16
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
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
123 words
A process for the production of polytetramethylene ether glycol comprising subjecting tetrahydrofuran to a ring opening polymerization at a temperature of -40° to 50° C. in the presence of: (a) a lithium halide selected from the group consisting of lithium chloride, lithium fluoride, lithium iodide, lithium bromide, and mixtures thereof and (b) fuming sulfuric acid containing free sulfuric anhydride in a concentration of 3 to 45 weight percent, the amount of the lithium halide being 0.001 to 20 percent by weight of the tetrahydrofuran, the amount of the fuming sulfuric acid being 3 to 60 percent by weight of the tetrahydrofuran, terminating the polymerization with water, and hydrolyzing the polymerization product to convert sulfuric acid terminal groups of the product to hydroxyl groups.
Claim 2
Dependent Claim
123 words
A process for the production of polytetramethylene ether glycol comprising subjecting tetrahydrofuran to a ring opening polymerization at a temperature of -40° to 50° C. in the presence of: (a) a lithium halide selected from the group consisting of lithium chloride, lithium fluoride, lithium iodide, lithium bromide, and mixtures thereof and (b) fuming sulfuric acid containing free sulfuric anhydride in a concentration of 3 to 45 weight percent, the amount of the lithium halide being 0.001 to 20 percent by weight of the tetrahydrofuran, the amount of the fuming sulfuric acid being 3 to 60 percent by weight of the tetrahydrofuran, terminating the polymerization with water, and hydrolyzing the polymerization product to convert sulfuric acid terminal groups of the product to hydroxyl groups.
Claim 3
Dependent Claim
17 words
A process as claimed in claim 1, wherein the lithium halide is lithium fluoride or lithium chloride.
Claim 4
Dependent Claim
26 words
A process as claimed in claim 2, wherein the lithium halide is used in an amount of 0.01 to 10 wt % based on the tetrahydrofuran.
Claim 5
Dependent Claim
26 words
A process as claimed in claim 2, wherein the lithium halide is used in an amount of 0.05 to 5 wt % based on the tetrahydrofuran.
Claim 6
Dependent Claim
25 words
A process as claimed in claim 2, wherein the fuming sulfuric acid contains free sulfuric anhydride in the concentration of 10 to 40 wt %.
Claim 7
Dependent Claim
27 words
A process as claimed in claim 2, wherein the fuming sulfuric acid is used in an amount of 5 to 45 wt % based on the tetrahydrofuran.
Claim 8
Dependent Claim
29 words
A process as claimed in claim 2, wherein the lithium halide and the fuming sulfuric acid are added to the tetrahydrofuran at a temperature of -40° to 50° C.
Claim 9
Dependent Claim
29 words
A process as claimed in claim 2, wherein the lithium halide and the fuming sulfuric acid are added to the tetrahydrofuran at a temperature of -20° to 30° C.
Claim 10
Dependent Claim
35 words
A process as claimed in claim 2, wherein the ring opening polymerization of the tetrahydrofuran is performed at a temperature of -40° to 50° C. for a time period of 30 minutes to 10 hours.
Claim 11
Dependent Claim
34 words
A process as claimed in claim 2, wherein the ring opening polymerization of the tetrahydrofuran is performed at a temperature of -20° to 30° C. for a time period of 1 to 5 hours.
Claim 12
Dependent Claim
21 words
A process as claimed in claim 2, wherein the ring opening polymerization of the tetrahydrofuran is conducted using an organic solvent.
Claim 13
Dependent Claim
42 words
A process as claimed in claim 11, wherein the organic solvent is selected from the group consisting of butane, pentane, hexane, octane, isooctane, cyclohexane, methylcyclohexane, decahydronaphthalene, methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, ethyl ether, isopropyl ether, butyl ether, isoamyl ether and dioxane.
Claim 14
Dependent Claim
26 words
A process as claimed in claim 11, wherein the organic solvent is used in an amount of 5 to 200 wt % based on the tetrahydrofuran.
Claim 15
Dependent Claim
20 words
A process as claimed in claim 2 wherein prior to said hydrolysis unreacted tetrahydrofuran is removed from the reaction mixture.
Claim 16
Dependent Claim
18 words
A process as claimed in claim 2 wherein said hydrolysis comprises heating the polymerization reaction mass with water.
Claim 17
Dependent Claim
32 words
A process as claimed in claim 15 wherein the total amount of water used to terminate the polymerization and to effect said hydrolysis is 50 to 300% by weight of the tetrahydrofuran.
Claim 18
Dependent Claim
29 words
A process as claimed in claim 15, wherein the heating is performed at a temperature of 70° to 100° C. for a time period of 1 to 3 hours.
Claim 19
Dependent Claim
41 words
A process as claimed in claim 16 wherein the hydrolyzed product is recovered by allowing the reaction mixture to separate into an organic layer and an aqueous layer, discarding the aqueous layer, and then washing the remaining organic layer with water.
Claim 20
Dependent Claim
70 words
A process as claimed in claim 17 wherein prior to the washing operation, the organic layer is mixed with an organic solvent selected from the group consisting of benzene, toluene, xylene and butanol in an amount of 50 to 300 wt % based on the weight of the tetrahydrofuran used in the polymerization, and then after the washing operation, the organic layer is vacuum distilled to remove the organic solvent.
References Cited (Backward Citations)
US3712930A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-24 | 1983-12-24 | 1984-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-24 | 1987-12-24 | 1988-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-24 | 1991-12-24 | 1992-06-24 | $7700.00 | Window Closed / Lapsed |