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:
Dec. 17, 2019
Filed:
Sep. 18, 2015
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Atsushi Yamamoto, Niigata-ken, JP;
Shinichi Kurotani, Niigata-ken, JP;
Atsuhiko Yonemochi, Niigata-ken, JP;
Mitsuo Narita, Niigata-ken, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
Provided is a method for efficiently and continuously producing a cellulose ether containing a reduced amount of indissoluble component. Specifically, the method includes a contact step of bringing pulp into contact with an alkali metal hydroxide solution in the presence of a heat removal solvent to obtain alkali cellulose; a reaction step of subjecting the alkali cellulose to a reaction with an etherifying agent; a partial condensation step, after completion of the reaction, of partially condensing a gas present in a reaction vessel used for the reaction to separate the gas into gas and liquid components for returning some or all of the gas component to the contact step for reuse as some or all of the heat removal solvent; and a step of incinerating the liquid component and, when all of the gas component is not returned to the contact step, the remainder of the gas component.