摘要:
Cellulose derivatives which are substituted in a specified manner by both carboxyalkyl groups and sulphoalkyl groups which are suitable in drilling fluids.
摘要:
Improved water soluble carboxymethylsulphoethyl celluloses may be obtained by suspending cellulose, adding compounds which transfer sulphoalkyl and carboxymethyl and then etherifying after alkalization.
摘要:
The present invention relates to a process for producing methyl hydroxyalkyl cellulose ethers by alkalisation and etherification of celluloses, rinsing the methyl hydroxyalkyl cellulose ethers with water at higher temperatures and recovering the short-chain cellulose ethers that are soluble in the wash water, wherein the wash water containing sodium chloride and organic by-products is passed across a first stage of a membrane filtration having a molecular cut size of 200 to 150,000 Dalton, is concentrated during this process and passes across a second stage of a membrane filtration.