PROBLEM TO BE SOLVED: To provide a method for efficiently producing a polysaccharide derivative of stable quality in an industrially advantageous manner with high productivity.SOLUTION: The method for producing a polysaccharide derivative includes the following steps (1) and (2) step (1): a step of obtaining a powdery polysaccharide derivative by reacting a polysaccharide with a compound having a reactive functional group in the presence of a basic catalyst, step (2): a step of obtaining a neutralization-treated product having a water content of 142-36 mass% by mixing the powdery polysaccharide derivative obtained in step (1) and an aqueous organic acid solution containing 0.5-1.5 equiv. of an organic acid with respect to the amount of the basic catalyst at an organic acid concentration of 1-80 mass%, using a mechanical agitation mixing device under the condition of a circumferential speed of a rotary blade of ≥0.5 m/s.COPYRIGHT: (C)2013,JPO&INPIT【課題】効率的かつ高い生産性で、品質の安定した多糖類誘導体を、工業的に有利に製造する方法を提供する。【解決手段】 下記工程(1)及び(2)を有する多糖類誘導体の製造方法。工程(1):塩基性触媒の存在下で、多糖類と反応性官能基を有する化合物とを反応させて、粉末状の多糖類誘導体を得る工程工程(2):機械撹拌式混合装置を用いて、工程(1)で得られた粉末状の多糖類誘導体と、該塩基性触媒に対して0.5~1.5当量の有機酸を含有する有機酸濃度1~80質量%の有機酸水溶液とを、回転翼周速が0.5m/s以上の条件下で混合して、水分含有量142~36質量%の中和処理物を得る工程【選択図】なし
