US 2025/0034285 A1Published application

Method of producing hydroxypropyl methylcellulose acetate succinate powder

AssigneeShin-Etsu Chemical Co., Ltd.

InventorsTomotaka MURAYAMA, Taishi KITAGUCHI, Akira KITAMURA, Itsuki TOHARA

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Abstract

Provided is a method of producing an esterified cellulose ether having improved flowability of the powder, where the method can reduce production of fine powder in the precipitated esterified cellulose ether. The method is a method of producing hydroxypropyl methylcellulose acetate succinate powder which essentially includes an esterification reaction step, a precipitation step, a washing/recovering step and a drying step, wherein the precipitation step is a step of extruding the reaction solution, prepared in the esterification reaction step, into water from extruding ports of an extruder to form a precipitate, and then mincing the resultant precipitate to obtain a suspension containing hydroxypropyl methylcellulose acetate succinate particles.

Claims4

Dependent claims

A method of producing hydroxypropyl methylcellulose acetate succinate powder comprising the steps of:

esterifying hydroxypropyl methylcellulose with an acetylating agent and a succinoylating agent in the presence of an aliphatic carboxylic acid to prepare a reaction solution containing hydroxypropyl methylcellulose acetate succinate;
extruding the reaction solution into water from one or more extruding ports of an extruder to form a precipitate, and then mincing the resultant precipitate to obtain a suspension containing hydroxypropyl methylcellulose acetate succinate particles,
washing the hydroxypropyl methylcellulose acetate succinate particles in the suspension and recovering the washed hydroxypropyl methylcellulose acetate succinate particles;
and
drying the washed hydroxypropyl methylcellulose acetate succinate particles.

2 more elements

Dependencies are inferred from the claim text.