| 摘要 |
The process for the preparation of water-soluble sodium carboxymethylcellulose (NaCMC) is carried out by etherifying alkali metal cellulose by means of a carboxyalkylating compound and optionally further etherifying agents in the presence of an alkaline liquid medium containing at least one organic, water-soluble solvent and water. In the process, a) the cellulose is first brought into contact with an excess of a liquid mixture of alkali metal hydroxide, water, an organic solvent and etherifying agent(s), b) the majority of the liquid mixture is removed from the solid, and subsequently c) the etherification reaction is carried out by increasing the temperature in the moist solid. The part of the liquid mixture separated from the moist solid can, after addition of consumed components, be repeatedly re-employed for the preparation of further NaCMC without distillative or other purification.
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