The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 2021
Filed:
Mar. 12, 2018
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Akira Kitamura, Joetsu, JP;
Mitsuhiro Yoshida, Joetsu, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
Provided is a method for producing hydroxypropyl methyl cellulose (HPMC) having high hydroxypropoxy content, low ash content, and low insoluble fiber content. More specifically, provided is a method for producing HPMC having a methoxy degree of substitution of from 1.4 to 2.2 and a hydroxypropoxy molar substitution of from 0.5 to 1.0, including steps of: bringing sheet-like or chip-like pulp into contact with an alkali metal hydroxide solution to obtain a reaction product mixture containing alkali cellulose, removing a liquid portion from the reaction product mixture to obtain the alkali cellulose, reacting the alkali cellulose with an etherifying agent to obtain a crude HPMC, disintegrating the crude HPMC into a disintegrated crude HPMC, dispersing the disintegrated crude HPMC in water to obtain a slurry, filtering the slurry to obtain a cake, and washing the cake.