Process for the production of a microfibrillated cellulose composition

Patent metadata

Field	Value
Publication number	US-2016145805-A1
Application number	US-201414899820-A
Country	US
Kind code	A1
Filing date	May 27, 2014
Priority date	Jun 20, 2013
Publication date	May 26, 2016
Grant date	—

Abstract

The present invention relates to a process for the production of microfibrillated cellulose composition, wherein the microfibrillated cellulose has an average fiber length in the range from 500 to 1300 μm and a percentage of fiber length in the category <200 μm of at least 15%, obtained by subjecting an aqueous mixture comprising 30 to 70% by weight of cellulose containing fibers to mechanical shearing at a temperature in the range of from >40° C. to <120° C. in the presence of at least one thermostable biocide, to the microfibrillated cellulose composition obtained in this process and their use in a process for production of paper, card and board comprising draining a paper stock comprising the microfibrillated cellulose composition with sheet formation in the wire.

First claim

1 . Process for the production of microfibrillated cellulose composition, wherein the microfibrillated cellulose has an average fiber length in the range from 500 to 1300 pm and a percentage of fiber length in the category ≦200 μm of at least 15%, obtained by subjecting an aqueous mixture comprising 30 to 70% by weight of cellulose containing fibers to mechanical shearing at a temperature in the range of from ≧40° C. to ≦120° C. in the presence of at least one thermostable biocide.

2 . The process according to claim 1 , wherein the cellulose containing fibers are bleached chemical pulp and/or wastepaper.

3 . The process according to claims 1 , wherein the cellulose containing fibers are mechanically sheared in a single screw, twin screw or conical extruder or with a refiner.

4 . The process according to claim 1 , wherein the microfibrillated cellulose has a freeness of>60 SR.

5 . The process according to claim 1 , wherein the microfibrillated cellulose has a BET surface area of 20 to 100 m 2 /g.

6 . The process according to claim 1 , wherein the mechanical shearing is performed with an energy input of 0.3 to 10 MWh/t of dry fiber.

7 . Process according to claim 1 , wherein the biocide is selected from the group consisting of 2H-isothiazol-3-one derivatives, glutaraldehyde, pyrithione and its derivatives, benzalkonium chloride or combinations thereof.

8 . Process according to claim 1 , wherein the biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, octylisothiazolinone, benzisothiazolinone, glutaraldehyde, sodium pyrithione, benzalkonium chloride.

9 . Microfibrillated cellulose composition obtained in a process according to claim 1 .

10 . Process for production of paper, card and board comprising adding to a paper stock the microfibrillated cellulose composition according to claim 9 , and optionally adding to the paper stock one or more papermaking additives, and then draining the paper stock on a moving screen to form a sheet, and then drying.

Assignees

• Basf Se

Inventors

• Kroener Hubertus
• Achatz Paul
• Kloke Philipp

Classifications

• D21C9/007

  by mechanical or physical means · CPC title

• D21H11/18 Primary

  Highly hydrated, swollen or fibrillatable fibres · CPC title

• D21C9/005

  organic compounds · CPC title

• C08B15/08

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

• D21C9/001 Primary

  Modification of pulp properties (purification D21C9/08) · CPC title