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US 7,683,110 B2Granted
Preparation of cellulose ether products of increased viscosity and fineness
AssigneeDow Global Technologies LLC
InventorsHartwig Schlesiger, Roland Bayer, Daniel Auriel, Jürgen Engelhardt, Frank Höhl, Erik-Andreas Klohr, Arne Henning Kull, Jörn-Bernd Pannek, Marc Oliver Schmidt
Life of this patent
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Abstract
The present invention relates to a process for preparing cellulose ether products which is characterized in that superabsorbent polymers (SAPs) are dried and milled, or mill-dried, conjointly with moist cellulose ether and also to the cellulose ether products resulting from this process.
Claims16
A process for preparing cellulose ethers of increased viscosity and increased fineness comprising:
- washing a crude cellulose ether to obtain a water-moist cellulose ether,
- mixing the water-moist cellulose ether, said water-moist cellulose ether having a moisture content in the range from 25% to 75% by weight, with 0.5% to 2.0% by weight based on the dry cellulose ether of a pulverulent superabsorbent polymer (SAP) to produce a millbase, and
- then drying and milling or mill-drying the millbase, whereby the fraction of produced cellulose ether passing through a 0.063 mm sieve is increased by more than 15% relative to a control cellulose ether prepared in the absence of an SAP.
Dependencies are inferred from the claim text.