| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-soluble carboxyethyl cellulose having excellent long-term stability and a method for producing the same. <P>SOLUTION: The carboxyethyl cellulose has a substitution degree of carboxyethyl group of 0.2-2.8, a substitution degree of carbamoyl ethyl group of ≤0.04 and a polymerization degree of 2-5,000. The method for producing carboxyethyl cellulose includes (a) a step for forming an alkali cellulose under specific conditions, (b) a step for pressing the alkali cellulose under specific conditions, (c) a step for reacting the alkali cellulose with acrylonitrile under specific conditions to synthesize cyanoethyl cellulose and (d) a step for converting the cyanoethyl cellulose to carboxyethyl cellulose under specific conditions in which the step (c) and the step (d) are carried out using a specific two-shaft type kneader. <P>COPYRIGHT: (C)2011,JPO&INPIT |
