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:
Jul. 16, 2019
Filed:
Jul. 23, 2015
Dai-ichi Kogyo Seiyaku Co., Ltd., Kyoto, JP;
DAI-ICHI KOGYO SEIYAKU CO., LTD., Kyoto, JP;
Abstract
A manufacturing method which includes: (1) an alkali cellulose reaction step wherein a mixed solvent having a mixing ratio (a mass ratio) of an alcohol having a carbon number of 3 or less and water of 75:25 to 95:5 is used, and the concentration of the base to the water is 25 to 40 mass %; (2) an etherification reaction step wherein a reaction is carried out under an excess base of 0.2 to 0.5 moles per unit of an anhydroglucose of the cellulose; (3) a neutralization step wherein acid is added to adjust the pH of the reaction mixture to 6.0 to 8.0; and (4) a heating step wherein the mixed solvent is removed, and a base is added to adjust the pH of the reaction mixture to 8.0 to 9.0, and then a heat treatment is performed at 40 to 70° C. for 30 to 120 minutes.