Process for Enhancing Dry Strength of Paper by Treatment with Vinylamine-Containing Polymers and Acrylamide-Containing Polymers

• US 20110155339A1
• Filed: 12/22/2010
• Published: 06/30/2011
• Est. Priority Date: 12/29/2009
• Status: Abandoned Application

• Current Assignee: Solenis Technologies LP (Innovative Water Care, LLC)
• Original Assignee: Solenis Technologies LP (Innovative Water Care, LLC)
• Inventors: Brungardt, Clement L., McKay, Jonathan M., Riehle, Richard J.
• Application Number:
  US12/975,441
• Publication Number:
  US 20110155339A1
• Time in Patent Office: Days
• US Class Current: 162/164.6
• CPC Class Codes: D21H 17/35 Polyalkenes, e.g. polystyrene
• CPC Class Codes: D21H 17/37 Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
• CPC Class Codes: D21H 17/375 Poly(meth)acrylamide
• CPC Class Codes: D21H 17/56 Polyamines; Polyimines; Polyester-imides
• CPC Class Codes: D21H 21/18 Reinforcing agents

Abstract

A process is disclosed for the production of paper with enhanced dry strength comprising adding to the wet end of a paper machine, (a) a vinylamine-containing aqueous solution polymer having a molecular weight of from 75,000 daltons to 750,000 daltons and (b) an amphoteric or cationic acrylamide-containing aqueous solution polymer having a molecular weight of from 75,000 daltons to 1,500,000 daltons, wherein the sum of the anionic and cationic monomers comprises at least 5% on a molar basis of the composition of the acrylamide-containing polymer.

Claims

1. A process for the production of paper, board, and cardboard with enhanced dry strength comprising adding to the wet end of a paper machine (a) a vinylamine-containing aqueous solution polymer having a molecular weight of from 75,000 daltons to 750,000 daltons and (b) an amphoteric or cationic acrylamide-containing aqueous solution polymer having a molecular weight of from 75,000 daltons to 1,500,000 daltons, wherein the sum of the anionic and cationic monomers comprises at least 5% on a molar basis of the composition of the acrylamide-containing monomer.

2. The process according to claim 1 wherein the active polymer content of the vinylamine containing aqueous solution polymer is from 5% to 30% on a dry weight basis and wherein the vinylamine-containing polymer has an N-vinylformamide content of at least 50% on a molar basis of the total monomer charged prior to hydrolysis, and at least 10% of the N-vinylformamide has been hydrolyzed in the final polymer.

3. The process according to claim 1 wherein the vinylamine-containing polymer has a molecular weight of from 150,000 daltons to 500,000 daltons.

4. The process according to claim 1 wherein the acrylamide-containing aqueous solution polymer contains a sum cationic and/or amphoteric monomer charge of from 5% to 50% on a molar basis, and has an active polymer content of from 5% to 50% on a weight basis.

5. The process according to claim 1 wherein the acrylamide-containing aqueous solution polymer is cationic and has a molecular weight of from 75,000 daltons to 750,000 daltons.

6. The process according to claim 1 wherein the acrylamide-containing aqueous solution polymer is an aqueous dispersion polymer.

7. The process according to claim 6 wherein the acrylamide-containing aqueous solution polymer is an aqueous dispersion polymer having a molecular weight of from 300,000 daltons to 1,500,000 daltons.

8. The process according to claim 6 wherein the acrylamide-containing aqueous solution polymer is an aqueous dispersion polymer having a molecular weight of from 400,000 daltons to less than 1,250,000 daltons.

9. The process according to claim 1, wherein the acrylamide-containing aqueous solution polymer contains a cationic monomer charge of from 5% to 50% on a molar basis, has an active polymer content of from 5% to 50% on a weight basis, and comprises a least one cationic monomer selected from the group consisting of:

diallyldimethylammonium chloride (DADMAC), 2-(dimethylamino)ethyl acrylate, 2-(dimethylamino)ethyl methacrylate, 2-(diethylaminoethyl) acrylate, 2-(diethylamino)ethyl methacrylate, 3-(dimethylamino)propyl acrylate, 3-(dimethylamino)propyl methacrylate, 3-(diethylamino)propyl acrylate, 3-(diethylamino)propyl methacrylate, N-[3-(dimethylamino)propyl]acrylamide, N-[3-(dimethylamino)propyl]methacrylamide, N-[3-(diethylamino)propyl]acrylamide, N-[3-(diethylamino)propyl]methacrylamide, [2-(acryloyloxy)ethyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [3-(acryloyloxy)propyl]trimethylammonium chloride, [3-(methacryloyloxy)propyl]trimethylammonium chloride, 3-(acrylamidopropyl)trimethylammonium chloride, and 3-(methacrylamidopropyl)trimethylammonium chloride.

10. The process according to claim 4, wherein the acrylamide-containing aqueous solution polymer has an overall amphoteric charge.

11. The process according to claim 10 wherein the acrylamide-containing aqueous solution polymer is amphoteric and has a molecular weight of from 75,000 daltons to 750,000 daltons.

12. The process according to claim 10, wherein the amphoteric acrylamide-containing aqueous solution is comprised of a polyelectrolyte complex consisting of an acrylamide-containing aqueous solution polymer and a cofactor carrying a complementary charge.

13. The process according to claim 12, wherein the amphoteric acrylamide-containing aqueous solution is comprised of a polyelectrolyte complex having a molecular weight of from 100,000 daltons to less than 1,000,000 daltons.

14. The process according to claim 1, wherein the vinylamine-containing polymer and the acrylamide-containing polymer are added to the papermachine as a single product blend.

15. The process according to claim 14, wherein the cationic portion of the acrylamide-containing polymer is generated by at least one monomer selected from the group consisting of diallyldimethylammonium chloride (DADMAC), N-[3-(dimethylamino)propyl]acrylamide, N-[3-(dimethylamino)propyl]methacrylamide, N-[3-(diethylamino)propyl]acrylamide, N-[3-(diethylamino)propyl]methacrylamide, 3-(acrylamidopropyl)trimethylammonium chloride, and 3-(methacrylamidopropyl)trimethylammonium chloride.

16. The process according to claim 15, wherein the cationic portion of the acrylamide-containing polymer is generated by at least one monomer selected from the group consisting of diallyldimethylammonium chloride (DADMAC), N-[3-(dimethylamino)propyl]acrylamide, N-[3-(dimethylamino)propyl]methacrylamide, 3-(acrylamidopropyl)trimethylammonium chloride, and 3-(methacrylamidopropyl)trimethylammonium chloride.

17. The process according to claim 1, wherein the vinylamine-containing polymer and the acrylamide-containing polymer are added to the wet end of a paper machine in a ratio of vinylamine-containing polymer to acrylamide-containing polymer of from 10:

1 to 1;

50 up to a sum total of 1.25% on a weight basis of the dry pulp, based on the active polymer solids of the polymeric products.

18. A paper product produced by the process of claim 1.