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:
Mar. 27, 2018
Filed:
Jul. 31, 2014
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Akira Kitamura, Niigata-ken, JP;
Mitsuo Narita, Niigata-ken, JP;
Takuya Yokosawa, Niigata-ken, JP;
Yuichi Nishiyama, Niigata-ken, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Provided are a method for producing a water-soluble cellulose ether having a low degree of polymerization and enhanced whiteness, and the like. The method includes the steps of: bringing a pulp powder having a multiplication product of less than 0.004 mmwhich is obtained by multiplying a number-average fiber length by a number-average fiber width, each measured with a Kajaani fiber length analyzer, into contact with an alkali metal hydroxide to obtain an alkali cellulose; reacting the alkali cellulose with an etherifying agent to obtain a crude water-soluble cellulose ether having a high degree of polymerization; purifying the crude water-soluble cellulose ether; drying the purified water-soluble cellulose ether; grinding the dried water-soluble cellulose ether into a water-soluble cellulose ether powder; and depolymerizing the water-soluble cellulose ether powder to obtain the water-soluble cellulose ether having a low degree of polymerization.