Glyoxalated inter-copolymers with high and adjustable charge density

• US 20060270801A1
• Filed: 05/25/2005
• Published: 11/30/2006
• Est. Priority Date: 05/25/2005
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Georgia-Pacific Resins, Inc. (KOCH Industries Incorporated)
• Inventors: Ringold, Clay E., Luo, Yuping, Hagiopol, Cornel, Townsend, David F., Favors, Karla D.
• Granted Patent: US 7,589,153 B2
• Time in Patent Office: Days
• US Class Current: 525/218
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2666/20 Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: D21H 17/375 Poly(meth)acrylamide
• CPC Class Codes: D21H 17/47 Condensation polymers of aldehydes or ketones
• CPC Class Codes: D21H 21/18 Reinforcing agents

Abstract

A method for making storage-stable glyoxalated inter-copolymers with higher and adjustable charge density suitable for use as a strengthening agent for paper. The glyoxalated inter-copolymers can be used to enhance the strength of paper, particularly recycled paper and mechanical printing paper.

Claims

1. A method for producing a glyoxalated inter-copolymer of high charge density useful for strengthening paper, comprising:

(a) reacting a first portion of glyoxal with a blended composition comprising (1) a polyacrylamide having pendant amide groups and (2) a high charge density polymer having pendant glyoxal-reactive groups to form a first mixture comprising a glyoxalated inter-copolymer of high charge density having separate segments of the polyacrylamide and the high charge density polymer.

2. The method of claim 1 further comprising:

(b) adding an acid to the first mixture to form a second mixture having reduced pH; and

(c) adding a second portion of the glyoxal to the second mixture to form a stabilized glyoxalated inter-copolymer.

3. The method of claim 1 wherein the polyacrylamide is a non-ionic polyacrylamide.

4. The method of claim 1 wherein the polyacrylamide is a cationic polyacrylamide.

5. The method of claim 4 wherein the cationic polyacrylamide comprises diallyl dimethyl ammonium chloride (DADMAC) in an amount of up to about 0.1 mole percent of the acrylamide monomer.

6. The method of claim 1 wherein the high charge density polymer is a polyamidoamine epichlorohydrin polymer.

7. The method of claim 6 wherein the polyamidoamine epichlorohydrin polymer is selected from a diethylenetriamine-adipic acid polyamidoamine epichlorohydrin;

a triethylenetetramine-adipic acid polyamido-amine epichlorohydrin;

adducts of a triethylenetetramine-adipic acid polyamidoamine epichlorohydrin polymer and an acrylamide;

inter-copolymers of primary amine-terminated cationic polyamidoamine and neutral polyacrylamide;

cationic polyacrylamides with a cationic comonomer concentration over 20% mole;

a cationic polyaminoamine onto which polyacrylamide is grafted;

cationic starches;

a cationic starch onto which a cationic polyacrylamide is grafted; and

blends thereof.

8. The method of claim 1 wherein the high charge density polymer is a dimethyl polyamine.

9. The method of claim 4 further comprising preparing the cationic polyacrylamide by free radical polymerization of an acrylamide monomer in the presence of a cationic co-monomer.

10. The method of claim 9 wherein the cationic co-monomer is selected from DADMAC, 2-vinylpyridine, 4-vinylpryridine, 2-methyl-5-vinyl pyridine, 2-vinyl-N-methylpyridinium chloride, p-vinylphenyl-trimethyl ammonium chloride, 2-(dimethylamino)ethyl methacrylate, trimethyl(p-vinylbenzyl)ammonium chloride, p-dimethylaminoethylstyrene, dimethylaminopropyl acrylamide, 2-methylacroyloxy-ethyltrimethyl ammonium methylsulfate, 3-acrylamido-3-methylbutyl trimethyl ammonium chloride and 2-(dimethylamino) ethyl acrylate.

11. The method of claim 9 wherein the cationic co-monomer is used in a concentration of 0.1-25 mole percent of the acrylamide monomer.

12. The method of claim 1 wherein the polyacrylamide is prepared by free radical polymerization of an acrylamide monomer and a cationic co-monomer in the presence of an aldehyde scavenger which is an adduct of choline chloride and acrylamide.

13. The method of claim 12 wherein the aldehyde scavenger has the structure:

14. The method of claim 13 wherein R¹ and R² are each hydrogen and A⁻

is chloride.

15. The method of claim 1 wherein the polyacrylamide is prepared in the presence of a di-functional monomer to obtain a branched structure.

16. The method of claim 15 wherein the di-functional monomer is selected from the group consisting of N,N′

-methylene-bisacrylamide, N,N′

-methylene-bismethacrylamide, N-allyl acrylamide, N-allyl methacrylamide and mixtures thereof.

17. The method of claim 15 wherein the di-functional monomer is used in a concentration of 0.01-5.0 mole percent of acrylamide monomer.

18. The method of claim 2 wherein the first portion of glyoxal is provided in an amount of 10 to 60 mole percent of the pendant amide groups.

19. The method of claim 2 wherein the second portion of glyoxal is from about 1 to about 75 weight percent of the first portion of glyoxal.

20. The method of claim 2 wherein the second portion of glyoxal is from about 4 to about 50 weight percent of the first portion of glyoxal.

21. The method of claim 1 further comprising adding an aldehyde scavenger to the first mixture.

22. The method of claim 2 further comprising including an aldehyde scavenger in one or more of step (a), step (b), step (c), and the stabilized glyoxalated inter-copolymer.

23. The method of claim 21 wherein the aldehyde scavenger is selected from the group consisting of lactic acid, malic acid, citric acid, and choline chloride.

24. The method of claim 21 wherein the aldehyde scavenger is added to the first mixture in an amount of 0.0001 to 0.25 mole per mole of total glyoxal.

25. The method of claim 21 wherein the aldehyde scavenger is an adduct of choline chloride and acrylamide.

26. The method of claim 25 wherein the aldehyde scavenger has the structure:

27. The method of claim 26 wherein R¹ and R² are each hydrogen and A⁻

is chloride.

28. The method of claim 25 wherein the aldehyde scavenger is present in step (a) in an amount ranging from about 0.1 to about 0.5 mole for each mole of total glyoxal.

29. The method of claim 25 wherein the aldehyde scavenger is present in step (b) in an amount ranging from about 0.01 to about 0.15 mole for each mole of total glyoxal.

30. The method of claim 25 wherein the aldehyde scavenger is present in step (c) in an amount ranging from about 0.01 to about 0.3 mole for each mole of glyoxal.

31. The method of claim 25 wherein the aldehyde scavenger is added to the stabilized glyoxalated inter-copolymer in an amount ranging from about 0.01 to about 0.3 mole for each mole of glyoxal.

32. A composition for enhancing the wet strength of paper prepared by the method of claim 1.

33. Paper strengthened by the composition of claim 32.