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US5385607A
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Water-soluble sulphoalkyl hydroxyalkyl derivatives of cellulose and their use in gypsum- and cement-containing compounds
Assignee: Dow Produktions und Vertriebs GmbH and Co OHG
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Filing: 1993-01-27
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Granted: 1995-01-31
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Expires: 2013-01-27
Abstract
Abstract The invention relates to a new class of water-soluble ionic cellulose derivatives and their use as additive for gypsum- and cement-containing compounds.
Inventors
- 👤 Rene Kiesewetter
- 👤 Klaus Szablikowski
- 👤 Werner Lange
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:46
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/193; C04; C04B; C04B24/00; C04B24/16; C04B24/161; C04B24/168; C04B24/24; C04B24/38; C04B24/383
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
42 words
A water-soluble, ionic, tertiary cellulose ether comprising cellulose etherified with (i) sulphoalkyl radicals with a degree of substitution (DS) of 0.001 to 0.6 and (ii) at least two radicals selected from the group consisting of hydroxyalkyl, alkoxyhydroxyalkyl, 3-alkoxy-2-hydroxyalkyl, aryl and arylalkyl radicals.
Claim 2
Dependent Claim
42 words
A water-soluble, ionic, tertiary cellulose ether comprising cellulose etherified with (i) sulphoalkyl radicals with a degree of substitution (DS) of 0.001 to 0.6 and (ii) at least two radicals selected from the group consisting of hydroxyalkyl, alkoxyhydroxyalkyl, 3-alkoxy-2-hydroxyalkyl, aryl and arylalkyl radicals.
Claim 3
Dependent Claim
16 words
A cellulose ether according to claim 1, wherein the sulphoalkyl DS is from 0.01 to 0.5.
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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) | 1998-01-30 | 1998-08-01 | 1999-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-30 | 2002-08-01 | 2003-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-30 | 2006-08-01 | 2007-01-31 | $7700.00 | Window Closed / Lapsed |