Increased drainage performance in papermaking systems using microfibrillated cellulose

Patent metadata

Field	Value
Publication number	US-10851498-B2
Application number	US-201715704583-A
Country	US
Kind code	B2
Filing date	Sep 14, 2017
Priority date	Sep 16, 2016
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A process for the production of paper, board, and cardboard is disclosed. The process results in improved drainage and comprises adding to the wet end of a paper machine (a) microfibrillated cellulose and (b) a coadditive. The coadditive can be one or more of (1) a cationic aqueous dispersion polymer, (2) colloidal silica, (3) bentonite clay and (4) vinylamine-containing polymers or combinations thereof.

First claim

The invention claimed is:

1. A process for the production of paper, board, and cardboard comprising adding to a wet end of a paper machine (a) microfibrillated cellulose, wherein the microfibrillated cellulose is derived from carboxylate-substituted cellulose with a net ionic charge having an anionic degree of substitution of 0.10 to 0.30; and (b) at least one coadditive, wherein the coadditive is selected from the group consisting of at least one of (1) an acrylamide-containing, cationic aqueous dispersion polymer having a molecular weight from 100,000 D to 500,000 D, a cationic monomer charge of 20% to 40%, and a reduced specific viscosity of from 5.0 to 12.0 dL/g and (2) vinylamine-containing polymers chosen from N-vinylformamide homopolymers that have been partially hydrolyzed to vinylamine and having an N-vinylformamide charge from at least 75% to 100% and a hydrolysis from 30% to 75%, in an amount effective to improve drainage, wherein the ratio by weight of the microfibrillated cellulose to the coadditive is from 1:5 to 5:1, and wherein the total combined amount of microfibrillated cellulose and coadditive added to the wet end of the paper machine is from 0.025% to 0.3% by weight on the basis of combined total solids of microfibrillated cellulose and coadditive with respect to the weight of dry pulp; and (c) aluminum sulfate in an amount of 0.025% to 0.5% by weight with respect to the weight of dry pulp.

2. The process of claim 1 wherein the net anionic charge is generated by directly oxidizing the cellulose with an N-oxide.

3. The process of claim 1 wherein the net anionic charge is generated by reaction of the cellulose with at least one derivitizing agent.

4. The process of claim 3 wherein the derivitizing agent is selected from the group consisting of chloroacetic acid, dichloroacetic acid, bromoacetic acid, dibromoacetic acid, salts thereof, and combination thereof.

5. The process of claim 1 , wherein the coadditive comprises the vinylamine containing polymer, wherein the vinylamine-containing polymer has a molecular weight of from 75,000 Daltons to 750,000 Daltons.

6. The process of claim 5 , wherein the vinylamine-containing polymer has a molecular weight of from 100,000 Daltons to 600,000 Daltons.

7. The process of claim 1 , wherein the coadditive comprises the cationic aqueous dispersion polymer.

8. The process of claim 7 wherein the cationic aqueous dispersion polymer is composed of two polymers (1) a cationic dispersant polymer with a molecular weight of from 10,000 to 150,000 Daltons, and (2) a cationic polymer of higher molecular weight which forms a discrete particle phase.

9. The process of claim 7 , wherein the coadditive further comprises bentonite clay.

10. The process of claim 7 , wherein the coadditive further comprises colloidal silica.

11. The process of claim 1 , where the ratio of the microfibrillated cellulose to the combined total amount of coadditives added to the wet end of the paper machine is from 1:5 to 2:1.

Assignees

• Solenis Tech Lp

Inventors

• Mckay Jonathan M

Classifications

• D21H21/10 Primary

  Retention agents or drainage improvers · CPC title

• D21H17/74

  of organic and inorganic material · CPC title

• D21H17/72

  of organic material · CPC title

• D21H17/68

  siliceous, e.g. clays · CPC title

• D21H17/56

  Polyamines; Polyimines; Polyester-imides · CPC title