CATIONIC CROSS-LINKED POLYMERS IN WATER-IN-WATER POLYMER DISPERSIONS

• US 20120202941A1
• Filed: 02/17/2012
• Published: 08/09/2012
• Est. Priority Date: 08/24/2009
• Status: Active Grant

• Current Assignee: Solenis Technologies LP (Olympus Water Holdings IV LP)
• Original Assignee: Ashland Licensing and Intellectual Property Llc
• Inventors: BROECHER, Markus, KANTO OEQVIST, Charlotta, SIEVERLING, Nathalie, BOEKELO, Christian
• Granted Patent: US 8,609,757 B2
• Time in Patent Office: Days
• US Class Current: 524/521
• CPC Class Codes: C08F 220/34 Esters containing nitrogen , e.g. N,N-dimethylaminoethyl (meth)acrylate
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 220/58 containing oxygen in addition to the carbonamido oxygen , e.g. N-methylolacrylamide, N-(meth)acryloylmorpholine
• CPC Class Codes: C08F 222/102 of dialcohols, e.g. ethylene glycol di(meth)acrylate or 1,4-butanediol dimethacrylate
• CPC Class Codes: C08F 222/103 of trialcohols, e.g. trimethylolpropane tri(meth)acrylate
• CPC Class Codes: C08F 222/385 Monomers containing two or more (meth)acrylamide groups, e.g. N,N'-methylenebisacrylamide
• CPC Class Codes: C08F 226/02 by a single or double bond to nitrogen

Abstract

The invention relates to water-in-water polymer dispersions containing cross-linked cationic polymers, methods for their preparation and their use. The water-in-water polymer dispersions are useful inter alia as flocculants, dewatering (drainage) aids and retention aids in papermaking.

Claims

1. A method for manufacturing a water-in-water polymer dispersion, the method comprising:

free radical polymerizing an aqueous reaction mixture comprising

(i) a cationic polymeric dispersant, and

(ii) a monomer composition comprising

(ii-a) at least 5 wt.-% of a non-ionic monomer of formula (I)

2. The method of claim 1, wherein the aqueous reaction mixture does not comprise any hydrophobic monomers.

3. The method of claim 1, wherein the cross-linker comprises 2, 3, 4, or 5 ethylenically unsaturated groups.

4. The method of claim 1, wherein the non-ionic monomer of formula (I) is selected from the group consisting of (meth)acrylamide, N-methyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethyl(meth)-acrylamide, N,N-diethyl(meth)acrylamide, N-methyl-N-ethyl(meth)acrylamide, and N-hydroxyethyl(meth)acrylamide.

5. The method of claim 1, wherein the cationic monomer of formula (II) is selected from the group consisting of a trimethylammoniumalkyl(meth)acrylate halide, a trimethylammoniumalkyl(meth)acrylamide halide, and a diallyldialkylammonium halide.

6. The method of claim 1, wherein the cationic polymeric dispersant is a water-soluble polymer having a weight average molecular weight M_w of at most 2.0×

10⁶ g/mol.

7. The method of claim 1, wherein the cationic polymeric dispersant is a cationic polymer derived from at least one second cationic monomer selected from the group consisting of a trimethylammoniumalkyl(meth)acrylate halide, a trimethylammoniumalkyl(meth)acrylamide halide, and a diallyldialkylammonium halide.

8. The method of claim 7, wherein the at least one second cationic monomer differs from the cationic monomer of formula (II).

9. The method of claim 1, further comprising:

before, after, or before and after the free radical polymerizing, adding a water-soluble salt in a quantity of 0.1 to 5.0 wt.-%, based on a total weight of the aqueous reaction mixture, to the aqueous reaction mixture.

16. The method of claim 2, wherein the cross-linker comprises 2, 3, 4, or 5 ethylenically unsaturated groups.

17. The method of claim 1, wherein the non-ionic monomer of formula (I) is (meth)acrylamide.

18. The method of claim 1, wherein the non-ionic monomer of formula (I) is N-methyl(meth)acrylamide.

19. The method of claim 1, wherein the non-ionic monomer of formula (I) is N-isopropyl(meth)acrylamide.

20. The method of claim 1, wherein the non-ionic monomer of formula (I) is N,N-dimethyl(meth)-acrylamide.

10. A water-in-water polymer dispersion comprising:

(i) a cationic polymeric dispersant and

(ii) a cross-linked cationic copolymer derived from a monomer composition comprising

(ii-a) at least 5 wt.-% of a non-ionic monomer of formula (I)

11. The dispersion of claim 10, obtained free radical polymerizing the monomer composition in the presence of (i) the cationic polymeric dispersant.

12. The dispersion of claim 10, which has a polymer content of 40±

20 based on a total weight of the dispersion.

13. The dispersion of claim 10, comprising 0.5 to 5.0 wt.-% of at least one selected from the group consisting of an acid and a salt,

wherein an overall content of acid and salt amounts to a maximum of 5.0 wt.-%, based on a total weight of the dispersion.

14. The dispersion of claim 10, where a relative weight ratio of cross-linked cationic copolymer to cationic polymeric dispersant is >

1;

1.

15. A flocculant,

a thickener,

a contaminant control,

a dry strength aid,

a retention agent, or drainage aid, comprising the dispersion of claim 10.