| 摘要 |
<p>In a process for making hydroxyethyl cellulose by agitating particulate cellulose in a mixture of alkali, water, hydroxethylating agent and tert.-butyl alcohol as a dispersant, the tert.-butyl alcohol contains 2-25% by weight of isopropyl alcohol. Etherification may be effected at e.g. 20-150 DEG C. using ethylene oxide, glycide, epichlorohydrin, butadiene monoxide or ethylene chlorohydrin. The cellulose may be wood-pulp, cotton linters, chemical cotton, pretreated with alkali or otherwise prepared for reduction to desired particle size by milling, shredding &c. In examples, hydroxyethyl cellulose of MS 1.56-2.12 is made by adding ethylene oxide to a mixture of cellulose, water, alkali, tert.-butyl alcohol and isopropyl alcohol at 30 DEG C., which is then heated in stages to 50 DEG and 80 DEG C. The dispersant/cellulose ratio is 10.4/1 ; the alkali/cellulose ratio is 0.32/1 ; the water/cellulose ratio is 1.8/1 . The hydroxyethyl cellulose is dehydrated by acetone.</p> |
