US4501887A
Expired / Lapsed
US
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Preparing cellulose ethers in a dimethoxyethane/(dispersing auxiliary) medium
Assignee: Clariant Produkte Deutschland GmbH
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Filing: 1984-02-17
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Granted: 1985-02-26
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Expires: 2004-02-17
Abstract
Abstract In modern processes for the preparation of cellulose ethers containing one or more types of substituents (such as MC, CMC, HEC, HPC, MHEC or EHEC), cellulose is reacted with etherifying agents in the presence of water, base and a mixture of preferably inert organic solvents (as a dispersing auxiliary). Dimethoxyethane (ethylene glycol dimethyl ether) and at least one organic solvent selected from the group including alkanols, alkane diols and alkoxy alkanols (for example, methanol and/or isopropanol) are employed in the mixture of organic solvents used for these syntheses, particularly in quantities of 1 to 30 parts by weight per 1 part by weight of cellulose.
Inventors
- 👤 Wolfgang Kornrumpf
- 👤 Eberhard Perplies
- 👤 Josef Hilbig
- 👤 Utz-Hellmuth Felcht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:07
CPC Classifications
C; C08; C08B; C08B11/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
76 words
In a process for preparing a cellulose ether from cellulose and etherifying agent in a reaction medium comprising base and inert organic solvent, the improvement wherein the inert organic solvent is an admixture of dimethoxyethane with at least one further organic solvent selected from the group consisting of alkanol, alkane diol and alkoxy alkanol, the admixture comprising from 0.1 to 50 percent by weight of the other organic solvent, based on the weight of the admixture.
Claim 2
Dependent Claim
76 words
In a process for preparing a cellulose ether from cellulose and etherifying agent in a reaction medium comprising base and inert organic solvent, the improvement wherein the inert organic solvent is an admixture of dimethoxyethane with at least one further organic solvent selected from the group consisting of alkanol, alkane diol and alkoxy alkanol, the admixture comprising from 0.1 to 50 percent by weight of the other organic solvent, based on the weight of the admixture.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1 which comprises (a) an alkalization stage followed by (b) an etherification stage.
Claim 4
Dependent Claim
21 words
A process as claimed in claim 2 wherein the alkalization stage is effected in reaction medium containing the further organic solvent.
Claim 5
Dependent Claim
27 words
A process as claimed in claim 3 wherein the reaction medium comprises from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose.
Claim 6
Dependent Claim
66 words
A process as claimed in claim 4 wherein the etherifying agent comprises at least one member selected from the group consisting of (a) an alkyl chloride having from 1 to 3 carbon atoms, (b) an alkylene oxide having from 2 to 4 carbon atoms, (c) a chloroalkanoic acid having from 2 to 4 carbon atoms, (d) a salt of (c) and (e) an ester of (c).
Claim 7
Dependent Claim
66 words
A process as claimed in claim 3 wherein the etherifying agent comprises at least one member selected from the group consisting of (a) an alkyl chloride having from 1 to 3 carbon atoms, (b) an alkylene oxide having from 2 to 4 carbon atoms, (c) a chloroalkanoic acid having from 2 to 4 carbon atoms, (d) a salt of (c) and (e) an ester of (c).
Claim 8
Dependent Claim
22 words
A process as claimed in claim 2 wherein the alkalization stage is effected in reaction medium free from the further organic solvent.
Claim 9
Dependent Claim
32 words
A process as claimed in claim 7 wherein the etherification stage is effected in reaction medium having from 1 to 30 parts by weight of dimethoxyethane per part by weight of cellulose.
Claim 10
Dependent Claim
66 words
A process as claimed in claim 8 wherein the etherifying agent comprises at least one member selected from the group consisting of (a) an alkyl chloride having from 1 to 3 carbon atoms, (b) an alkylene oxide having from 2 to 4 carbon atoms, (c) a chloroalkanoic acid having from 2 to 4 carbon atoms, (d) a salt of (c) and (e) an ester of (c).
Claim 11
Dependent Claim
66 words
A process as claimed in claim 7 wherein the etherifying agent comprises at least one member selected from the group consisting of (a) an alkyl chloride having from 1 to 3 carbon atoms, (b) an alkalene oxide having from 2 to 4 carbon atoms, (c) a chloroalkanoic acid having from 2 to 4 carbon atoms, (d) a salt of (c) and (e) an ester of (c).
Claim 12
Dependent Claim
32 words
A process as claimed in claim 7 wherein the etherification stage is effected in reaction medium, up to 30 percent of the total organic solvent of which is said further organic solvent.
Claim 13
Dependent Claim
62 words
A process according to claim 1 wherein alkanol is a C 1 to C 5 alkanol, alkane diol is a C 2 or C 3 alkane diol or an oligomeric or polymeric compound containing units constituted by one or both of these diols and alkoxy alkanol is a (C 1 to C 4 ) alkoxy (C 2 or C 3 ) alkanol.
Claim 14
Dependent Claim
27 words
A reaction medium comprising cellulose, etherifying agents, base, dimethoxyethane and at least one further organic solvent selected from the group consisting of alkanol, alkane diol and alkoxyalkanol.
Claim 15
Dependent Claim
27 words
A reaction medium comprising cellulose, etherifying agents, base, dimethoxyethane and at least one further organic solvent selected from the group consisting of alkanol, alkane diol and alkoxyalkanol.
Claim 16
Dependent Claim
23 words
A reaction medium according to claim 13 which contains water and wherein the further organic solvent comprises C 1 to C 5 alkanol.
Claim 17
Dependent Claim
40 words
A reaction medium according to claim 13 which contains water and wherein the further organic solvent comprises C 2 or C 3 alkane diol or an oligomeric or polymeric compound containing units constituted by one or both of these diols.
Claim 18
Dependent Claim
32 words
A reaction medium according to claim 13 which contains water and wherein the further organic solvent comprises a (C 1 to C 4 ) alkoxy (C 2 or C 3 ) alkanol.
Claim 19
Dependent Claim
45 words
An admixture of dimethoxyethane with at least one other organic solvent selected from the group consisting of alkanol, alkane diol and alkoxy alkanol, the admixture comprising from 0.1 to 30 percent by weight of the other organic solvent, based on the weight of the admixture.
Claim 20
Dependent Claim
45 words
An admixture of dimethoxyethane with at least one other organic solvent selected from the group consisting of alkanol, alkane diol and alkoxy alkanol, the admixture comprising from 0.1 to 30 percent by weight of the other organic solvent, based on the weight of the admixture.
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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) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |