US4316982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for reducing the viscosity of cellulose ethers by means of ozone and application thereof
Assignee: Hoechst AG
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Filing: 1980-04-23
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Granted: 1982-02-23
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Expires: 2000-04-23
Abstract
Abstract This invention relates to a process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether which is moist with water and has a dry content of from 20 to 95% by weight is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0 DEG to 60 DEG C.
Inventors
- 👤 Arno Holst
- 👤 Eberhard Perplies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:44
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether which is moist with water and has a dry content of from 40 to 75% by weight is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0° to 60° C.
Claim 2
Dependent Claim
63 words
A process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether which is moist with water and has a dry content of from 40 to 75% by weight is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0° to 60° C.
Claim 3
Dependent Claim
22 words
A process as claimed in claim 1 wherein the reaction is carried out at a temperature between about 15° and 40° C.
Claim 4
Dependent Claim
33 words
A process for manufacturing a water-soluble cellulose ether which comprises (a) alkalizing cellulose, (b) etherifying, (c) washing out, (d) reducing the viscosity in accordance with the process of claim 1, and (e) drying.
Claim 5
Dependent Claim
104 words
A process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether is selected from the group consisting of hydroxyalkyl cellulose which has a hydroxyalkyl group containing from 2 to 4 carbon atoms, alkyl cellulose which has an alkyl group containing 1 or 2 carbon atoms, or one of the mixed ethers thereof, which is moist with water and has a dry content of from 40 to 75% by weight, is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0° to 60° C.
Claim 6
Dependent Claim
104 words
A process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether is selected from the group consisting of hydroxyalkyl cellulose which has a hydroxyalkyl group containing from 2 to 4 carbon atoms, alkyl cellulose which has an alkyl group containing 1 or 2 carbon atoms, or one of the mixed ethers thereof, which is moist with water and has a dry content of from 40 to 75% by weight, is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0° to 60° C.
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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) | 1985-02-22 | 1985-08-24 | 1986-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-22 | 1989-08-24 | 1990-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-22 | 1993-08-24 | 1994-02-23 | $7700.00 | Window Closed / Lapsed |