Coating compositions containing reactive diluents and methods

1. A method of preparing a coating composition, the method comprising:

providing a mixture comprising a water-dispersible polymer and a substantially non-irritating reactive diluent;

wherein the water-dispersible polymer is prepared in the presence of the reactive diluent;

wherein the mixture has a viscosity below 100,000 centipoise at processing temperatures;

wherein the reactive diluent:

includes a compound having a molecular weight of 350 grams/mole to 1000 grams/mole and having a viscosity at 25° C. of no greater than 2,000 cps;

is substantially free of ethylene oxide moieties, propylene oxide moieties, and primary hydroxyl functionality;

has an average ethylenically unsaturated functionality of at least 3.0;

is present in an amount of 5 wt-% to 40 wt-%, based on the total weight of the reactive diluent and the water-dispersible polymer; and dispersing the mixture in water.

2. A method of preparing a coating composition, the method comprising:

mixing water, a surfactant, and a substantially non-irritating reactive diluent, wherein the reactive diluent:

includes a compound having a molecular weight of 350 grams/mole to 1000 grams/mole and having a viscosity at 25° C. of no greater than 2,000 cps,

is substantially free of ethylene oxide moieties, propylene oxide moieties, and primary hydroxyl functionality,

has an average ethylenically unsaturated functionality of at least 3.0,

is present in an amount of 5 wt-% to 40 wt-%, based on the total weight of the reactive diluent and the water-dispersible polymer; and

blending this mixture with a water-dispersible polymer and water; wherein the water-dispersible polymer is prepared in the presence of the reactive diluent.

3. The method of claim 1 wherein the method includes chain extending the water-dispersible polymer after dispersing it in water with the reactive diluent.

4. The method of claim 2 wherein the method includes chain extending the water-dispersible polymer after blending it in water and the mixture with the reactive diluent.

5. The method of claim 1 wherein the water-dispersible polymer is selected from the group consisting of polyurethanes, epoxies, polyamides, chlorinated polyolefins, acrylics, oil-modified polymers, polyesters, and mixtures or copolymers thereof.

6. The method of claim 5 wherein the water-dispersible polymer is a water-dispersible polyurethane.

7. The method of claim 6 wherein the water-dispersible polyurethane comprises amine or acid functionality.

8. The method of claim 6 wherein the water-dispersible polyurethane comprises ethylenic unsaturation.

9. The method of claim 8 wherein the ethylenic unsaturation comprises (meth)acrylate functionality.

10. The method of claim 8 wherein the ethylenic unsaturation comprises auto-oxidative carbon-carbon double bonds.

11. The method of claim 10 wherein the coating composition further comprises a metal drier.

12. The method of claim 1 wherein the reactive diluent comprises a (meth)acrylate, a vinyl ether, a (meth)allyl ether, or mixtures or copolymers thereof.

13. The method of claim 12 wherein the reactive diluent comprises a (meth)acrylate-functional compound.

14. The method of claim 13 wherein the (meth)acrylate-functional compound is selected from the group consisting of di-(trimethylolpropane tetraacrylate), di-(trimethylolpropane tetramethacrylate), and combinations thereof.

15. The method of claim 1 further comprising a free-radical initiator.

16. The method of claim 1 wherein the reactive diluent is present in an amount of 10 wt-% to 30 wt-%, based on the total weight of the reactive diluent and the water-dispersible polymer.

17. The method of claim 1 comprising no more than 7 wt-% volatile organic compounds.

18. The method of claim 1 wherein the reactive diluent comprises a compound selected from the group of di-(trimethylolpropane tetraacrylate), di-(trimethylolpropane tetramethacrylate), di-(pentaerythritol hexamethacrylate), dipentaerythritol hexaacrylate, pentaerythritol tetramethacrylate, di-(trimethylolpropane tetravinyl ether), di-(pentaerythritol hexavinyl ether), pentaerythritol tetravinyl ether, di-(trimethylolpropane tetraallyl ether), di-(trimethylolpropane tetramethallyl ether), di-(pentaerythritol hexaallyl ether), di-(pentaerythritol hexamethallyl ether), pentaerythritol tetraallyl ether, pentaerythritol tetramethallyl ether, and mixtures thereof.

19. The method of claim 1 wherein the water-dispersible polymer is an oil-modified water-dispersible polymer.

20. The method of claim 19 wherein the oil-modified water dispersible polymer is selected from the group consisting of an alkyd, an oil-modified water-dispersible polyurethane, an oil-modified water-dispersible epoxy, an oil-modified water-dispersible polyamide, an oil-modified water-dispersible acrylic, and mixtures or copolymers thereof.

21. The method of claim 20 wherein the oil-modified water-dispersible polymer is an oil-modified water-dispersible polyurethane.

22. The method of claim 20 wherein the oil-modified water-dispersible polymer is an alkyd.

23. The method of claim 19 wherein the reactive diluent comprises a (meth)acrylate, a vinyl ether, a (meth)allyl ether, or mixtures or copolymers thereof.

24. The method of claim 23 wherein the reactive diluent comprises a (meth)acrylate-functional compound.

25. The method of claim 24 wherein the (meth)acrylate-functional compound is selected from the group consisting of di-(trimethylolpropane tetraacrylate), di-(trimethylolpropane tetramethacrylate), and combinations thereof.

26. The method of claim 19 wherein the coating composition further comprises a metal drier.

27. The method of claim 19 wherein the reactive diluent is present in an amount of 10 wt-% to 30 wt-%, based on the total weight of the reactive diluent and the oil-modified water-dispersible polymer.

28. The method of claim 19 comprising no more than 7 wt-% volatile organic compounds.

29. The method of claim 1 wherein the water-dispersible polymer comprises an oil-modified polymer chemically modified to be water-dispersible.