Method for producing microfibrillated cellulose and microfibrillated cellulose

Patent metadata

Field	Value
Publication number	US-10329359-B2
Application number	US-201515522475-A
Country	US
Kind code	B2
Filing date	Oct 29, 2015
Priority date	Oct 29, 2014
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

The invention relates to a method for producing microfibrillated cellulose, where a suspension comprising cellulose derivative in a liquid phase which comprises an organic solvent is provided. The suspension of cellulose derivative is mechanically treated and microfibrillated cellulose is obtained. At least a part of the liquid phase from the microfibrillated cellulose is separated and microfibrillated cellulose with a dry solids content of >30 weight-% is obtained.

First claim

The invention claimed is:

1. A method for producing microfibrillated cellulose, comprising steps
(a) providing a suspension comprising a cellulose derivative in a liquid phase which comprises 50-100 weight-% of an organic solvent and 0-50 weight-% of water,
(b) mechanically treating the suspension of the cellulose derivative by homogenization or fluidization and obtaining microfibrillated cellulose, and
(c) separating at least a part of the liquid phase from the microfibrillated cellulose and obtaining microfibrillated cellulose with a dry solids content of >30 weight-%,
wherein the cellulose derivative is selected from the group consisting of carboxymethyl cellulose, TEMPO-oxidized cellulose and microcrystalline cellulose, and the organic solvent is alcohol, acetone or any mixture thereof.

2. The method according to claim 1 , wherein the carboxymethyl cellulose has degree of substitution DS<0.6.

3. The method according to claim 1 , wherein the microcrystalline cellulose is produced through acid hydrolysis of cellulose material.

4. The method according to claim 1 , wherein the alcohol is selected from the group consisting of ethanol, methanol, and tert-butanol.

5. The method according to claim 1 , wherein in step (c) is obtained microfibrillated cellulose with a dry solids content of >40 weight-%.

6. The method according to claim 1 , wherein in step (a) the suspension comprising cellulose derivative is obtained by replacing and/or displacing water in an aqueous suspension comprising cellulose derivative by the organic solvent.

7. The method according to claim 1 , wherein the dry solids content of the suspension comprising cellulose derivative during the mechanical treatment, is <15 weight %.

8. The method according to claim 1 , wherein the separated liquid phase comprising organic solvent is recirculated from step (c) back to step (a).

Assignees

• Kemira Oyj

Inventors

• Lillandt Marcus
• Vuorenpalo Veli-Matti
• Vanhatalo Kari

Classifications

• D21H11/20 Primary

  Chemically or biochemically modified fibres · CPC title

• C08B15/08

  Fractionation of cellulose, e.g. separation of cellulose crystallites · CPC title

• C08L1/02

  Cellulose; Modified cellulose · CPC title

• D21H21/14

  characterised by function or properties in or on the paper (D21H19/66, D21H27/02 take precedence) · CPC title

• C08B15/02 Primary

  Oxycellulose; Hydrocellulose; {Cellulosehydrate, e.g. microcrystalline cellulose} · CPC title