US4363924A
Expired / Lapsed
US
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Depolymerization of polytetramethylene glycol ethers
Assignee: BASF SE
•
Filing: 1981-10-22
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Granted: 1982-12-14
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Expires: 2001-10-22
Abstract
Abstract A process for depolymerizing polytetramethylene glycol ethers, wherein the latter are heated at from 90° to 180° C. in the presence of a bleaching earth.
Inventors
- 👤 Herbert Mueller
- 👤 Otto H. Huchler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:06
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/30; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08; C08G65/04; C08G65/06; C08G65/16; C08G65/20; C08G65/32; C08G65/321; C08G65/324; C08G2650/00; C08G2650/02; C08G2650/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
A process for depolymerizing polytetramethylene glycol ethers which comprises heating a polytetramethylene glycol ether in the presence of a bleaching earth at from 90° to 180° C.
Claim 2
Dependent Claim
27 words
A process for depolymerizing polytetramethylene glycol ethers which comprises heating a polytetramethylene glycol ether in the presence of a bleaching earth at from 90° to 180° C.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1, wherein the mixture is heated at from 100° to 150° C.
Claim 4
Dependent Claim
25 words
A process as claimed in claim 1, wherein from 0.1 to 5 percent by weight, based on polytetramethylene glycol ether, of bleaching earth is used.
Claim 5
Dependent Claim
27 words
A process as claimed in claim 3 wherein the amount of bleaching earth used is about 1 to 2 percent by weight, based on polytetramethylene glycol ether.
Claim 6
Dependent Claim
27 words
A process as claimed in claims 1, 2 or 3 wherein the polytetramethylene glycol ether is heated in a reaction mixture substantially free of salt and acid.
Claim 7
Dependent Claim
23 words
A process as claimed in claims 1, 2 or 3 wherein said bleaching earth is an acid-treated aluminum hydrosilicate of the montmorillonite group.
References Cited (Backward Citations)
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Cited
US3433829A
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US3925484A
Cited
US4115408A
Cited
US4233228A
Cited
JPS5661048A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |