Method for producing nanofibrillated cellulose

Patent metadata

Field	Value
Publication number	US-2016376749-A1
Application number	US-201315039722-A
Country	US
Kind code	A1
Filing date	Dec 19, 2013
Priority date	Nov 26, 2013
Publication date	Dec 29, 2016
Grant date	—

Abstract

The present invention relates to a method for preparing nanofibrillated cellulose capable of producing high-quality cellulose nanofibrils by a simple process without using the conventional enzymatic treatment, in which a cellulose aqueous dispersion is homogenized by adding an aqueous alkaline solution having a pH between 8 and 14 thereto so that the aqueous alkaline solution aids the swell of an amorphous region of cellulose, thereby promoting the nanofibrillation of cellulose during the homogenizing process.

First claim

1 . A method for preparing nanofibrillated cellulose, comprising:
dispersing pulp in water to obtain an aqueous dispersion of pulp (Step 1); adding an aqueous alkaline solution having a pH between 8 and 14 to the aqueous dispersion of pulp to obtain a dispersed aqueous alkaline solution of pulp (Step 2); and homogenizing the dispersed aqueous alkaline solution of pulp to obtain a homogenized material (Step 3).

2 . The method according to claim 1 , further comprising mechanically refining the aqueous dispersion of pulp after Step 1 (Step 1-1).

3 . The method according to claim 1 , wherein the aqueous alkaline solution having a pH between 8 and 14 is an aqueous ammonia solution.

4 . The method according to claim 1 , further comprising stirring the dispersed aqueous alkaline solution of pulp after Step 2 (Step 2-1).

5 . The method according to claim 1 , further comprising drying the homogenized material after Step 3 (Step 3-1).

6 . The method according to claim 1 , wherein the pulp in Step 1 is a wood pulp.

7 . The method according to claim 1 , wherein the amount of pulp of the aqueous alkaline solution in Step 2 is from 0.1 vol % to 20 vol % relative to the amount of the dispersed aqueous alkaline solution of pulp.

8 . The method according to claim 1 , wherein the homogenizing in Step 3 is performed by passing the dispersed aqueous alkaline solution of pulp through a homogenizer.

9 . The method according to claim 8 , wherein the internal pressure of the homogenizer is in the range from 70 MPa to 310 MPa.

10 . The method according to claim 8 , wherein the nozzle diameter of the homogenizer is in the range from 50 to 250 μm.

11 . The method according to claim 1 , wherein the mean size of the nanofibrillated cellulose prepared after Step 3 is 100 nm or less.

Assignees

• Korea Ind Tech Inst

Inventors

• Lim Dae Young
• Kim Ki Young
• Lee Jin Ah

Classifications

• C08B15/00 Primary

  Preparation of other cellulose derivatives or modified cellulose {, e.g. complexes} · CPC title

• D21C3/024 Primary

  with NH3 or H2O · CPC title

• D21C9/002

  by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives · CPC title

• D21C9/007

  by mechanical or physical means · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title