Phosphoric acid-esterified fine cellulose fiber and method for producing the same

Patent metadata

Field	Value
Publication number	US-2016115249-A1
Application number	US-201414891255-A
Country	US
Kind code	A1
Filing date	May 16, 2014
Priority date	May 16, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

Objects of the present invention are to provide a phosphoric acid-esterified fine cellulose fiber of which slurry shows superior transparency, and to provide a method for producing a phosphorylated fine cellulose fiber showing superior transparency with good efficiency and high yield. According to the present invention, there is provided a phosphoric acid-esterified fine cellulose fiber, of which 0.2 mass % aqueous dispersion shows a solution haze of 15% or lower.

First claim

1 . A phosphoric acid-esterified fine cellulose fiber, of which 0.2 mass % aqueous dispersion shows a solution haze of 15% or lower.

2 . The phosphoric acid-esterified fine cellulose fiber according to claim 1 , which contains 0.6 mmol/g or more of phosphoric acid groups, and wherein difference of introduction amounts of strongly acidic groups and weakly acidic groups derived from phosphoric acid groups introduced into the cellulose is 0.5 mmol/g or smaller.

3 . The phosphoric acid-esterified fine cellulose fiber according to claim 1 , which has a polymerization degree of 400 or higher as determined by the copper ethylenediamine method.

4 . The phosphoric acid-esterified fine cellulose fiber according to claim 1 , which is produced by a method comprising (a) a step of allowing a compound having a phosphoric acid group or/and a salt thereof to act on a fiber raw material containing cellulose in the presence of urea or/and a derivative thereof to introduce phosphoric acid groups into the fiber raw material, and (b) a step of refining the fiber raw material wherein phosphoric acid groups are introduced in the step (a).

5 . The phosphoric acid-esterified fine cellulose fiber according to claim 4 , wherein yield of the fiber raw material is 70% or higher at the time point that the fiber raw material resulting from the step (a) is subjected to the step (b).

6 . The phosphoric acid-esterified fine cellulose fiber according to claim 4 , wherein amount of phosphoric acid groups introduced in one time of the phosphoric acid group-introducing reaction in the step (a) is 1.2 mmol/g or smaller.

7 . A method for producing a phosphoric acid-esterified fine cellulose fiber, which comprises (a) a step of allowing a compound having a phosphoric acid group or/and a salt thereof to act on a fiber raw material containing cellulose in the presence of urea or/and a derivative thereof to introduce phosphoric acid groups into the fiber raw material, and (b) a step of refining the fiber raw material wherein phosphoric acid groups are introduced in the step (a), and wherein difference of introduction amounts of strongly acidic groups and weakly acidic groups derived from phosphoric acid groups introduced into the cellulose is made to be 0.5 mmol/g or smaller.

8 . The method for producing a phosphoric acid-esterified fine cellulose fiber according to claim 7 , wherein yield of the fiber raw material is 70% or higher at the time point that the fiber raw material resulting from the step (a) is subjected to the step (b).

9 . The method for producing a phosphoric acid-esterified fine cellulose fiber according to claim 7 , wherein amount of phosphoric acid groups introduced in one time of the phosphoric acid group-introducing reaction in the step (a) is 1.2 mmol/g or smaller.

10 . The method for producing a phosphoric acid-esterified fine cellulose fiber according to claim 7 , wherein the phosphoric acid group-introduced fiber raw material to be subjected to the step (b) has 0.6 mmol/g or more of phosphoric acid groups.

Assignees

• Oji Holdings Corp

Inventors

• Noguchi Yuichi
• Noishiki Yasutomo
• HOMMA Ikue

Classifications

• D21H17/10

  Phosphorus-containing compounds · CPC title

• C08B5/00 Primary

  Preparation of cellulose esters of inorganic acids {, e.g. phosphates (rendering cellulose suitable for esterification C08B1/02)} · CPC title

• D21H13/06

  Cellulose esters · CPC title

• D01F2/24 Primary

  from cellulose derivatives · CPC title