| 摘要 |
PURPOSE:To obtain the titled metal salt having very excellent transparency, by applying ultrasonic vibration in any one of an alkali cellulose forming reaction step and other steps in the production of an alkali metal salt of CMC. CONSTITUTION:Crushed raw pulp is dispersed in a mixture of isopropyl alcohol and water. The dispersion is stirred to carry out a pretreatment and the reaction bath is sealed with a nitrogen gas. An aq. NaOH soln. is added thereto. While ultrasonic vibration is applied to the reaction soln. with ultrasonic waves generated by an ultrasonic cleaner, etc., the soln. is stirred to carry out an alkali cellulose forming reaction. A soln. of monochloroacetic acid in isopropyl alcohol is added thereto. For example, monochloroacetic acid is thoroughly mixed at 15-20 deg.C, and the temp. is elevated to about 70 deg.C to carry out an etherification reaction. The reaction mixture is cooled to about 40 deg.C, neutralized and filtered. If desired, washing and filtration are repeated. The reaction product is dried at about 90 deg.C to obtain the desired product. Said ultrasonic vibration may be applied in a monochloroacetic acid mixing step or an etherification step, instead of the alkali cellulose forming reaction step.
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