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US 4,015,067 AGranted
Method of preparing polysaccharide ethers and apparatus
AssigneeThe Dow Chemical Company
InventorsGordon Y. T. Liu, Carl P. Strange
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Abstract
Polysaccharide ethers are prepared in a novel continuous process in which a slurry of a polysaccharide, an alkali metal hydroxide, and an etherifying agent, with or without an inert diluent, are mixed in the substantial absence of molecular or free oxygen and fed through a sinuous tubular reactor under pressure, so that the etherification reaction is continuous. The apparatus for preparing the reaction mixture is also novel.
Claims17
A method of preparing an ether of a polysaccharide comprising
- 1. continuously preparing a slurry of a finely divided polysaccharide, an alkali metal hydroxide in an amount sufficient to provide from about 0.25 to about 1.7 parts by weight based on the polysaccharide, and an etherifying ingredient with or without an inert carrier fluid in the substantial absence of free oxygen,
- 2. feeding said slurry into a tubular reactor, free of obstructions to passage of the slurry, under a pressure of from about 100 to about 400 psig at a rate to provide a reaction period of from about 10 to about 60 minutes at a temperature of from about 30 to about 135.degree. C.
- 3. removing the reacted slurry from the reactor and
- 4. purifying and recovering the ether of the polysaccharide.
1 more element
Dependencies are inferred from the claim text.