Masterbatch, rubber composition, and methods for producing the same

Patent metadata

Field	Value
Publication number	US-11118020-B2
Application number	US-201616063884-A
Country	US
Kind code	B2
Filing date	Dec 21, 2016
Priority date	Dec 25, 2015
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

Disclosed herein is method for preparing a masterbatch by dispersing chemically modified cellulose nanofibers having carboxy groups under acidic conditions and then mixing the dispersed cellulose nanofibers with rubber latex. More specifically, the present disclosure provides a method for producing a masterbatch, including: (A) a step of introducing a carboxy group to a cellulose-based raw material to prepare a modified cellulose; (B) a step of carrying out defibration treatment and dispersion treatment of the modified cellulose to prepare a cellulose nanofiber; (C) a step of acidifying the cellulose nanofiber to prepare an acid type cellulose nanofiber; and (D) a step of mixing the acid type cellulose nanofiber and a rubber component. The rubber composition having excellent strength such as tensile strength can be provided by using the obtained masterbatch.

First claim

The invention claimed is:

1. A method for producing a masterbatch, the method comprising:
(A) introducing a carboxy group to a cellulose-based raw material to prepare a modified cellulose;
(B) carrying out a defibration treatment and a dispersion treatment of the modified cellulose to prepare a modified cellulose nanofiber;
(C) acidifying the modified cellulose nanofiber to a pH of 2 to 5 to obtain a gel precipitate of aggregated acidified modified cellulose nanofibers; and
(D) mixing the gel precipitate of the aggregated acidified modified cellulose nanofibers and a rubber component, to obtain a masterbatch.

2. The method according to claim 1 , further comprising:
carrying out a washing treatment after the acidifying (C).

3. The method according to claim 1 , wherein the introducing (A) of the carboxy group comprising introducing a carboxy group by oxidation or carboxymethylation.

4. The method according to claim 1 , wherein the modified cellulose nanofiber is an oxidized cellulose nanofiber having an amount of carboxy groups of 0.5 mmol/g to 3.0 mmol/g relative to an absolutely dried weight of the modified cellulose nanofiber.

5. The method according to claim 1 , wherein the modified cellulose nanofiber is a carboxymethylated cellulose nanofiber having a degree of carboxymethyl substitution of 0.01 to 0.50 per glucose unit of the modified cellulose nanofiber.

6. A method for producing a rubber composition, the method comprising:
producing a masterbatch by the method of claim 1 and preparing the rubber composition with the masterbatch.

Assignees

• Jujo Paper Co Ltd

Inventors

• Ito Kotaro
• Yasukawa Yusuke

Classifications

• B29B7/92

  Wood chips or wood fibres · CPC title

• B29B7/7495

  for mixing rubber · CPC title

• B29B7/002

  Methods (chemical aspects C08J3/00) · CPC title

• C08B15/04

  Carboxycellulose, e.g. prepared by oxidation with nitrogen dioxide · CPC title

• C08B11/12

  substituted with carboxylic radicals {, e.g. carboxymethylcellulose [CMC]} · CPC title