US 11,753,483 B2
Hydroxypropyl methyl cellulose acetate succinate and method for producing the same
Taishi Kitaguchi, Niigata (JP); Junichi Matsubara, Niigata (JP); and Mitsuhiro Yoshida, Niigata (JP)
Assigned to Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on Oct. 29, 2020, as Appl. No. 17/83,615.
Claims priority of application No. 2019-200033 (JP), filed on Nov. 1, 2019.
Prior Publication US 2021/0130497 A1, May 6, 2021
Int. Cl. C08B 3/16 (2006.01); B01F 7/00 (2006.01); B01F 27/1122 (2022.01); B01F 27/1125 (2022.01); B01F 27/1145 (2022.01)
CPC C08B 3/16 (2013.01) [B01F 27/1122 (2022.01); B01F 27/1125 (2022.01); B01F 27/1145 (2022.01)] 2 Claims
 
1. A method for producing hydroxypropyl methyl cellulose acetate succinate comprising:
an esterification step of reacting hydroxypropyl methyl cellulose with an acetylating agent and a succinoylating agent in the presence of an aliphatic carboxylic acid in a kneader reactor equipped with two or more stirring blades rotating around their own axes and orbitally revolving, to obtain a reaction product solution containing hydroxypropyl methyl cellulose acetate succinate;
a precipitation step of precipitating the hydroxypropyl methyl cellulose acetate succinate by mixing the reaction product solution with water to obtain a suspension of the precipitated hydroxypropyl methyl cellulose acetate succinate; and
a washing and recovering step of washing the hydroxypropyl methyl cellulose acetate succinate in the suspension and recovering the washed hydroxypropyl methyl cellulose acetate succinate.