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:
Apr. 04, 2017
Filed:
Dec. 22, 2006
Mitsuo Narita, Joetsu, JP;
Masaki Tabata, Joetsu, JP;
Atsushi Yoshida, Joetsu, JP;
Hiroshi Umezawa, Joetsu, JP;
Mitsuo Narita, Joetsu, JP;
Masaki Tabata, Joetsu, JP;
Atsushi Yoshida, Joetsu, JP;
Hiroshi Umezawa, Joetsu, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
The invention is a method for efficiently preparing alkali cellulose having a uniform alkali distribution therein. More specifically, pulp and an excess alkali metal hydroxide solution are introduced continuously in a screw conveyor type contactor and brought into contact with each other in the screw conveyor type reactor. By changing at least one factor selected from the group consisting of a rotation speed of the screw conveyor, a screw pitch and a length of immersion zone, a ratio of an alkali to cellulose in the alkali cellulose obtained by draining is controlled. The alkali cellulose thus obtained is etherified into the corresponding cellulose ether.