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:
Feb. 19, 2013
Filed:
Mar. 25, 2009
Shoichi Miyawaki, Tokyo, JP;
Shiho Katsukawa, Tokyo, JP;
Hiroshi Abe, Tokyo, JP;
Yuko Iijima, Tokyo, JP;
Akira Isogai, Tokyo, JP;
Shoichi Miyawaki, Tokyo, JP;
Shiho Katsukawa, Tokyo, JP;
Hiroshi Abe, Tokyo, JP;
Yuko Iijima, Tokyo, JP;
Akira Isogai, Tokyo, JP;
Nippon Paper Industruies Co., Ltd., Tokyo, JP;
Abstract
A papermaking additive comprising cellulose nanofibers whose aqueous solution at a concentration of 2% (w/v) has a B-type viscosity (60 rpm, 20° C.) of 500 to 7000 mPa·s, preferably 500 to 2000 mPa·s is used to prepare a paper having improved air resistance and smoothness. This additive is prepared by oxidizing a cellulosic material with an oxidizing agent in the presence of (1) N-oxyl compound(s) and (2) bromide, iodide or a mixture thereof to prepare oxidized cellulose, and finely grinding the oxidized cellulose in a wet condition to convert the oxidized cellulose into nanofibers.