UV-curable coating compositions, multi-component composite coatings, and related coated substrates

• US 8,901,198 B2
• Filed: 11/05/2010
• Issued: 12/02/2014
• Est. Priority Date: 11/05/2010
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Kania, Charles M., Phelps, Kenneth T., Humbert, Kurt A., Roper, Todd M., Shao, Jiping, Martin, David C.
• Primary Examiner(s): MCCLENDON, SANZA L
• Application Number:
  US12/940,168
• Publication Number:
  US 20120115975A1
• Time in Patent Office: 1,488 Days
• Field of Search: 522/90, 522/96, 522/113, 522/114, 522/120, 522/121, 522/150, 522/152, 522/151, 522/174, 522/8, 522 24- 30
• US Class Current: 522/174
• CPC Class Codes: C08F 2/48 by ultraviolet or visible light
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• CPC Class Codes: C09D 175/16 having terminal carbon-to-carbon unsaturated bonds

Abstract

Disclosed herein are solventborne liquid UV-curable coating compositions comprising: a radiation curable compound comprising an acrylate-terminated compound having greater than two unsaturated sites, wherein the acrylate-terminated compound comprises a reaction product of reactants comprising: an adduct of a polyisocyanate, wherein the adduct of a polyisocyanate comprises a reaction product of reactants comprising a polyisocyanate comprising greater than two isocyanate groups and a compound having groups reactive with the isocyanate groups of the polyisocyanate; and an active hydrogen-containing acrylate; and a photoinitiator composition that includes a first photoinitiator composition for providing surface cure and a second photoinitiator composition for providing through cure of the resultant coating layer. Also disclosed are related multi-component composite coatings, coated substrates, and methods for coating a substrate.

Claims

1. A solventborne liquid UV-curable coating composition comprising:

a. an acrylate-terminated compound having greater than two unsaturated sites, wherein the acrylate-terminated compound comprises a reaction product of reactants comprising;

(i) an adduct of a polyisocyanate, wherein the adduct of a polyisocyanate comprises a reaction product of reactants comprising a polyisocyanate comprising greater than two isocyanate groups and a compound having groups reactive with the isocyanate groups of the polyisocyanate; and

(ii) an active hydrogen-containing acrylate; and

b. a first photoinitiator composition comprising a first photoinitiator having a peak absorbance with a wavelength range of 250 to 260 nm and second photoinitiator having a peak absorbance with a wavelength range of 240 to 250 nm; and

c. a second photoinitiator composition which absorbs UV light with a wavelength range of 350 to 410 nm.

2. The solventborne liquid UV-curable coating composition of claim 1, wherein said second photoinitiator composition comprises between about 0.05 and 0.95 weight percent of the total weight of the solventborne liquid UV-curable coating composition.

3. The solventborne liquid UV-curable coating composition of claim 1, wherein (i) the second photoinitiator having a peak absorbance with a wavelength range of 240 to 250 nm comprises a mixture comprising two photoinitiators each having a peak absorbance with a wavelength range of 240 to 250 nm.

4. The solventborne liquid UV-curable coating composition of claim 1, wherein the acrylate-terminated compound has an acid value less than 5 mg KOH/g.

5. The solventborne liquid UV-curable coating composition of claim 1, wherein there are no free isocyanate groups present on the acrylate-terminated compound.

6. The solventborne liquid UV-curable coating composition of claim 1, wherein the polyisocyanate comprises an isocyanurate of isophorone diisocyanate, an isocyanurate of hexamethylene diisocyanate, or combinations thereof.

7. The solventborne liquid UV-curable coating composition of claim 1, wherein the compound having groups reactive with the isocyanate groups of the polyisocyanate comprises a polyol, a polyamine, a polythiol, or combinations thereof.

8. The solventborne liquid UV-curable coating composition of claim 1, wherein the active hydrogen-containing acrylate comprises hydroxyl-functional acrylates, amine-functional acrylates, or combinations thereof.

9. The solventborne liquid UV-curable coating composition of claim 8, wherein the hydroxyl-functional acrylate comprises hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, hydroxyl vinyl ether, acrylate ester of glycidyl versatate, or combinations thereof.

10. The solventborne liquid UV-curable coating composition of claim 7, wherein the polyol does not contain an acid group.

11. The solventborne liquid UV-curable coating composition of claim 7, wherein the polyol comprises a diol.

12. The solventborne liquid UV-curable coating composition of claim 11, wherein the diol comprises C₂ to C₅₀ carbon atoms.

13. The solventborne liquid UV-curable coating composition of claim 11, wherein the diol contains alkyl branching.

14. The solventborne liquid UV-curable coating composition of claim 12, wherein the diol comprises monoethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, decanediol, dodecanediol, neopentylglycol, cyclohexanediol, or combinations thereof.

15. The solventborne liquid UV-curable coating composition of claim 1, wherein the acrylate-terminated compound is not water-reducible and/or water-dispersible.

16. The solventborne liquid UV-curable coating composition of claim 1, wherein the molar ratio of the polyisocyanate to the compound having groups reactive with the isocyanate groups of the polyisocyanate is 2:

1.

17. The solventborne liquid UV-curable coating composition of claim 1 further comprising a resin other than the acrylate-terminated compound.

18. The solventborne liquid UV-curable coating composition of claim 1, wherein the composition is capable of cure upon exposure to a combination of thermal energy and radiation.

21. A substrate coated with a coating deposited from the solventborne liquid UV-curable coating composition of claim 1.

25. The solventborne liquid UV-curable coating composition of claim 1, wherein the first photoinitiator comprises a Type 2 hydrogen abstraction type photoinitiator.

26. The solventborne liquid UV-curable coating composition of claim 1, wherein the second photoinitiator comprises a Type 1 alpha-cleavage type photoinitiator.

19. A solventborne liquid UV-curable coating composition comprising:

(a) an acrylate-terminated compound having greater than two unsaturated sites, wherein the acrylate-terminated compound comprises a reaction product of reactants comprising;

(i) an adduct of a polyisocyanate, wherein the adduct of a polyisocyanate comprises a reaction product of reactants comprising a polyisocyanate comprising greater than two isocyanate groups and a compound having groups reactive with the isocyanate groups of the polyisocyanate; and

(ii) an active hydrogen-containing acrylate;

(b) a first photoinitiator composition comprising a first photoinitiator having a peak absorbance with a wavelength range of 250 to 260 nm; and

(c) a melamine group-containing polyethylenically unsaturated compound.

20. The solventborne liquid UV-curable coating composition of claim 19, wherein said melamine group-containing polyethylenically unsaturated compound comprises from 5 to 30 weight percent of the total weight of resin solids in the solventborne liquid UV-curable coating composition.

24. The multi-component composite coating composition of claim 20, wherein (1) the second photoinitiator having a peak absorbance with a wavelength range of 240 to 250 nm comprises a mixture comprising two photoinitiators each having a peak absorbance with a wavelength range of 240 to 250 nm.

22. A multi-component composite coating composition comprising:

(a) a basecoat deposited from a pigmented film-forming composition; and

(b) a transparent topcoat applied over at least a portion of the basecoat, wherein the transparent topcoat is deposited from a solventborne liquid UV-curable coating composition comprising;

(i) an acrylate-terminated compound having greater than two unsaturated sites, wherein the acrylate-terminated compound comprises a reaction product of reactants comprising;

an adduct of a polyisocyanate, wherein the adduct of a polyisocyanate comprises a reaction product of reactants comprising a polyisocyanate comprising greater than two isocyanate groups and a compound having groups reactive with the isocyanate groups of the polyisocyanate, and an active hydrogen-containing acrylate;

(ii) a first photoinitiator composition comprising a first photoinitiator having a peak absorbance with a wavelength range of 250 to 260 nm; and

second photoinitiator having a peak absorbance with a wavelength range of 240 to 250 nm; and

(iii) a second photoinitiator composition which absorbs UV light with a wavelength range of 350 to 410 nm;

wherein the acrylate-terminated compound does not comprise polyether groups.

23. The multi-component composite coating composition of claim 22, wherein said second photoinitiator composition comprises between about 0.05 and 0.95 weight percent of the total weight of the solventborne liquid UV-curable coating composition.