Heat-curable powder coating composition

Patent metadata

Field	Value
Publication number	US-10399113-B2
Application number	US-201514863383-A
Country	US
Kind code	B2
Filing date	Sep 23, 2015
Priority date	Nov 7, 2008
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

The disclosure relates to a heat curable powder coating composition suitable for being cured at a temperature from 60 to 130° C. containing: a thermal initiation system and a resin system, wherein the reactivity of the thermal initiation system is such that the thermal initiation system provides a geltime between 2.5 and 1000 minutes at 60° C. in butane diol-dimethacrylate as measured according to DIN 16945 using 1 wt % of the thermal initiation system in 99 wt % of butane dioldimethacrylate, wherein the amount of thermal initiation system is chosen such that when the powder coating composition is applied to a substrate and cured at a temperature of 130° C. for 20 minutes.

First claim

The invention claimed is:

1. A heat curable powder coating composition suitable for being cured at a temperature from 60 to 130° C. comprising:
a thermal initiation system and a resin system; wherein
the reactivity of the thermal initiation system is such that the thermal initiation system provides a geltime between 2.5 and 1000 minutes at 60° C. in butane diol-dimethacrylate as measured according to DIN 16945:1989-03 using 1 wt % of the thermal initiation system in 99 wt % of butane diol-dimethacrylate; and wherein
the amount of thermal initiation system is chosen such that when the powder coating composition is applied to a substrate and cured at a temperature of 130° C. for 20 minutes, the resulting coating resists at least 50 acetone double rubs; and wherein
the resin system comprises a resin and a co-crosslinker; and wherein
the resin contains reactive unsaturations which are carbon carbon double bonds connected directly to an electron withdrawing group; and wherein
the resin is a polyester; and wherein
the co-crosslinker is chosen from the group of acrylates, methacrylates, vinylesters, vinylethers, vinyl amides, alkyn ethers, alkyn esters, alkyn amides, alkyn amines, propargyl ethers, propargyl esters, itaconates, enamines and mixtures thereof; and wherein
the weight per unsaturation (WPU) of the co-crosslinker is higher than 150 and lower than 870 g/mole as determined using 1 H NMR; and wherein
the weight per unsaturation in the resin system is between 100 and 1000 g/mole as determined using 1 H NMR; and wherein
the powder coating composition is a one component system.

2. The composition according to claim 1 , wherein the geltime is at least 6 minutes and less than 1000 minutes.

3. The composition according to claim 1 , wherein the thermal initiation system comprises a peroxide.

4. The composition according to claim 3 , wherein, the peroxide is any of the following initiators: peranhydrides, peroxydicarbonates.

5. The composition according to claim 1 , wherein the reactive unsaturations are based on fumaric acid, maleic acid and/or itaconic acid.

6. The composition according to claim 1 , wherein the reactive unsaturations are based on fumaric acid and/or maleic acid.

7. The composition according to claim 1 , wherein the thermal initiation system comprises hydroquinones or catechols.

8. The composition according to claim 1 , wherein the co-crosslinker is chosen from the group of vinylethers, vinylesters, methacrylates, acrylates, itaconates and mixtures thereof.

9. The composition according to claim 1 , wherein the co-crosslinker is chosen from the group of vinylethers, vinylesters, itaconates and mixtures thereof.

10. The composition according to claim 1 , wherein the co-crosslinker is chosen from the group of vinylethers, vinylesters and mixtures thereof.

11. The composition according to claim 10 , wherein the resin has an acid value of less than 5 mg KOH per g resin.

12. The composition according to claim 1 , wherein the co-crosslinker is a vinylether.

13. The composition according to claim 12 , wherein the resin has an acid value of less than 5 mg KOH per g resin.

14. The composition according to claim 1 , wherein the resin has a hydroxyl value in the range of from 0 to 70 mg KOH per g resin.

15. The composition according to claim 1 , wherein the weight per unsaturation of the co-crosslinker is higher than 150 g/mole and lower than 650 g/mole.

16. The composition according to claim 1 , wherein the weight per unsaturation of the co-crosslinker is higher than 150 g/mole and lower than 630 g/mole.

17. The composition according to claim 1 , wherein the weight per unsaturation of the resin is less than 1500 g/mole as determined using 1 H NMR.

18. The composition according to claim 1 , wherein the weight per unsaturation of the resin is less than 1150 g/mole as determined using 1 H NMR.

19. The composition according to claim 1 , wherein the weight per unsaturation of the co-crosslinker is higher than 150 g/mole and lower than 630 g/mole and wherein the weight per unsaturation of the resin is less than 1150 g/mole.

20. The composition according to claim 1 , wherein the resin and the co-crosslinker are the same.

21. The composition according to claim 1 , wherein the resin and the co-crosslinker are the same and the thermal initiation system comprises hydroquinones or catechols.

22. The composition according to claim 1 , wherein the resin is a polyester based on fumaric acid, wherein the co-crosslinker is a vinylether and wherein the thermal initiation system comprises a perdicarbonate and a hydroquinone.

23. The composition according to claim 22 , wherein the perdicarbonate is di(4-t-butylcyclohexyl)peroxydicarbonate or dimyristyl peroxydicarbonate, and wherein the hydroquinone is tert-butylhydroquinone or 2,3,5-trimethylhydroquinone.

24. The composition according to claim 1 , wherein the resin is a polyester based on fumaric acid, wherein the co-crosslinker is a vinylether and wherein the thermal initiator is benzoyl peroxide.

25. The composition to claim 1 , wherein the thermal initiation system comprises transition metal compounds of transition metals with atomic numbers from/equal to 21 up to/equal to 79.

26. The composition according to claim 1 , wherein the thermal initiation system comprises transition metal compounds of Mn, Fe, Co or Cu.

27. The composition according to claim 1 , wherein the thermal initiation system comprises metal salts or complexes or mixtures thereof of Mn, Fe, Co or Cu.

28. The composition according to claim 1 , wherein the resin has a glass transition temperature of at least 40° C. as measured via DSC at a heating rate of 5° C./min.

29. The composition according to claim 1 , wherein the resin has a glass transition temperature of at least 45° C. as measured via DSC at a heating rate of 5° C./min.

30. The composition according to claim 1 , wherein the resin has a glass transition temperature of at least 40 and of at most 65° C. as measured via DSC at a heating rate of 5° C./min.

31. The composition according to claim 1 , wherein the resin has a number average molecular weight in the range of from 1500 to 8000 Da.

32. The composition according to claim 1 , wherein the resin has a number average molecular weight in the range of from 2100 to 4000 Da.

33. The composition according to claim 1 , wherein
the reactive unsaturations of the resin are based on maleic acid, fumaric acid, itaconic acid, acrylic acid and/or methacrylic acid, said resin has a hydroxyl value in the range of from 0 to 70 mg KOH per g resin and a number average molecular weight in the range of from 1500 to 8000 Da and a glass transition temperature of at least 40° C. as measured via DSC at a heating rate of 5° C./min; and
the co-crosslinker has a WPU higher than 150 g/mole and lower than 630 g/mole and said co-crosslinker is chosen from the group of vinylethers, vinylesters and mixtures thereof.

34. The composition according to claim 33 , wherein the reactive unsaturations of the resin are based on fumaric acid and/or maleic acid.

35. The composition according to claim 1 , wherein
the reactive unsaturations of the resin are based on maleic acid, fumaric acid, itaconic acid, acrylic acid and/or methacrylic

Assignees

• Dsm Ip Assets Bv

Inventors

• Jansen Johan F G A
• Molhoek Leendert Jan
• Drijfhout Jan Pieter

Classifications

• B05C19/04

  the particulate material being projected, poured or allowed to flow onto the surface of the work (B05C19/02 takes precedence; involving spraying or electrostatic projection B05B ){(B05C19/005 takes precedence)} · CPC title

• C08G63/127

  Acids containing aromatic rings · CPC title

• C09D5/033 Primary

  characterised by the additives · CPC title

• C08J2467/06

  Unsaturated polyesters · CPC title

• C08F283/01

  on to unsaturated polyesters {(C08F283/004 takes precedence)} · CPC title