Patent US4460766A successfully refreshed from Google Patents.
US4460766A
Expired / Lapsed
US
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Dispersing auxiliary for preparing cellulose ethers
Assignee: Clariant Produkte Deutschland GmbH
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Filing: 1982-11-19
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Granted: 1984-07-17
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Expires: 2002-11-19
Abstract
Abstract In modern processes for preparing cellulose ethers containing one or more types of substituents, such as MC, CMC, HEC, HPC, MHEC or EHEC, cellulose is reacted with an etherifying agent in the presence of water, base and at least one inert organic solvent (as a dispersing auxiliary). Dimethoxyethane (ethylene glycol dimethyl ether) is employed as a new organic solvent for these syntheses, particularly in quantities of 1 to 30 parts by weight per part by weight of cellulose.
Inventors
- 👤 Utz-Hellmuth Felcht
- 👤 Eberhard Perplies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:04
CPC Classifications
C; C08; C08B; C08B11/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
A process for producing a cellulose ether from cellulose and etherifying agent in a reaction mixture containing water, base and at least one organic solvent, the organic solvent comprising from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose in the reaction mixture.
Claim 2
Dependent Claim
48 words
A process for producing a cellulose ether from cellulose and etherifying agent in a reaction mixture containing water, base and at least one organic solvent, the organic solvent comprising from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose in the reaction mixture.
Claim 3
Dependent Claim
20 words
A process according to claim 1 which comprises two sequential stages: (a) an alkalization stage and (b) an etherification stage.
Claim 4
Dependent Claim
16 words
A process according to claim 2 wherein a reaction mixture in the alkalization stage comprises dimethoxyethane.
Claim 5
Dependent Claim
16 words
A process according to claim 2 wherein a reaction mixture in the etherification stage comprises dimethoxyethane.
Claim 6
Dependent Claim
14 words
A process according to claim 2 wherein dimethoxyethane is employed subsequent to stage (a).
Claim 7
Dependent Claim
53 words
A process according to claim 1 wherein the etherifying agent is a C 1 to C 3 alkyl chloride, a C 2 to C 4 alkylene oxide, a C 2 to C 4 chloroalkanoic acid, a C 2 to C 4 choroalkanoic acid salt or a combination of at least two such agents.
Claim 8
Dependent Claim
14 words
A process according to claim 1 wherein the organic solvent consists essentially of dimethoxyethane.
Claim 9
Dependent Claim
38 words
In a reaction medium for producing cellulose ether and containing cellulose, base, water and organic solvent, the improvement wherein the organic solvent comprises from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose.
Claim 10
Dependent Claim
38 words
In a reaction medium for producing cellulose ether and containing cellulose, base, water and organic solvent, the improvement wherein the organic solvent comprises from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose.
Claim 11
Dependent Claim
12 words
A reaction medium according to claim 8 which further comprises etherifying agent.
Claim 12
Dependent Claim
15 words
A reaction medium according to claim 8 wherein the organic solvent consists essentially of dimethoxyethane.
Claim 13
Dependent Claim
12 words
A reaction medium according to claim 10 which further comprises etherifying agent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |