Aqueous dispersion of transparent powder coating material

• US 6,485,793 B1
• Filed: 03/02/2001
• Issued: 11/26/2002
• Est. Priority Date: 08/04/1998
• Status: Expired due to Fees

• Current Assignee: BASF Coatings AG (BASF SE)
• Original Assignee: BASF Coatings AG (BASF SE)
• Inventors: Königer, Rainer, Ott, Günther, Schwalm, Reinhold, Binder, Horst, Meisenburg, Uwe, Blum, Rainer, Bendix, Maximilian, Woltering, Joachim
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US09/762,119
• Time in Patent Office: 634 Days
• Field of Search: 427/385.5, 427/508, 427/517, 427/375
• US Class Current: 427/508
• CPC Class Codes: C08G 59/3209 obtained by polymerisation of unsaturated mono-epoxy compounds
• CPC Class Codes: C09D 5/02 Emulsion paints including aerosols

Abstract

The present invention relates to an aqueous dispersion comprising a solid pulverulent component A and an aqueous component B, said component A comprising a UV-curable powder coating material.

Claims

1. A process comprising:

a) applying an aqueous dispersion to a substrate, wherein the dispersion comprises a solid pulverulent component A as disperse phase, and an aqueous component B as continuous phase, wherein component A comprises a UV-curable powder coating material;

b) heating the dispersion and melting the powder coating material to form a film, wherein at least a portion of the water is not removed prior to the melting, and

c) applying ultraviolet radiation to crosslink the film.

2. The process of claim 1, wherein a portion of the water is evaporated from the dispersion prior to melting.

3. The process of claim 1, wherein water is not removed prior to the melting.

4. The process of claim 1, wherein the dispersion is prepared by a process comprising:

a) preparing a dispersion from the solid pulverulent component A and the component B, and

b) grinding the resulting dispersion;

c) adjusting the pH to a desired pH with a pH agent, and

d) filtering the dispersion.

5. The process of claim 1, wherein component A comprises at least one UV-curable solid binder and a compound selected from the group consisting of pigments, dyes, and mixtures thereof.

6. The process of claim 1, wherein component A comprises a mixture of unsaturated polymers and polymers having a fraction of photochemically excitable, copolymeric photoinitiators.

7. The process of claim 1, wherein component A further comprises a compound selected from the group consisting of catalysts, devolatilizing agents, leveling agents, UV absorbers, free-radical scavengers, antioxidants, biocides, wetting agents, and mixtures thereof.

8. The process of claim 1, wherein component B comprises at least one of a thickener, a dispersion auxiliary, a neutralizing agent, a solvent, and a water retention agent.

9. The process of claim 8, wherein the thickener comprises a nonionic thickener comprising at least one nonionic associative thickener whose structural features comprise

i) a hydrophilic structure and

ii) hydrophobic groups cable of associative interaction in an aqueous medium.

10. The process of claim 9, wherein the thickener is a nonionic associative thickener comprising as the hydrophilic structure (i) polyurethane chains.

11. The process of claim 1, wherein component A further comprises a photoinitiator.

12. The process of claim 11, wherein the photoinitiator is a polymer-bonded photoinitiator.

13. The process of claim 1, wherein component A further comprises a UV stabilizer.

14. The process of claim 1, wherein component B further comprises a photoinitiator.

15. The process of claim 14, wherein the photoinitialor is a polymer-bonded photoinitiator.

16. The process of claim 1, wherein component B further comprises a UV stabilizer.

17. The process of claim 1, wherein component A and component B each further comprise a photoinitiator.

18. The process of claim 1, wherein component A and component B each further comprise a UV stabilizer.

19. The process of claim 1, wherein component B further comprises compounds selected from the group consisting of catalysts, devolatilizing agents, leveling agents, UV absorbers, free-radical scavengers, antioxidants, biocides, solvents, wetting agents, and mixtures thereof.

20. The process of claim 19, wherein the wetting agent is selected from the group consisting of straight-chain aliphatic dicarboxylic acids, carboxy-functional polyesters, and mixtures thereof.

21. The process of claim 19, wherein component B comprises an amine neutralizing agent.

22. The process of claim 7, wherein the wetting agent is selected from the group consisting of straight-chain aliphatic dicarboxylic acids, carboxy-functional polyesters, and mixtures thereof.

23. The process of claim 7, wherein component B further comprises an amine neutralizing agent.

24. The process of claim 1, wherein component A further comprises a compound selected from the group consisting of catalysts devolatilizing agents, leveling agents, UV absorbers, free-radical scavengers, antioxidants, biocides, wetting agents, and mixtures thereof, and component B further comprises a compound selected from the group consisting of catalysts, devolatilizing agents, leveling agents, UV absorbers, free-radical scavengers, antioxidants, biocides, solvents, wetting agents, and mixtures thereof.

25. The process of claim 24, wherein the wetting agent is selected from the group consisting of straight-chain aliphatic dicarboxylic acids, carboxy-functional polyesters, and mixtures thereof.

26. The process of claim 24, wherein component B further comprises an amine neutralizing agent.