UV-curable coatings
UV-curable coating compositions are provided including (in weight %) 5-50% cycloaliphatic crosslinker of the formula wherein R is wherein X is a C 1-4 straight chain, 20-55% of a summed amount of an oxetane crosslinker and an epoxy diluent, 35-45% epoxy functionalized silicon nanoparticles, 1-5% epoxy silane adhesion promoter and 0.5-2% photoinitiator.
1. An ultraviolet (UV)-curable coating composition comprising (in weight %) 5-50% cycloaliphatic crosslinker of the formula
wherein R is
wherein X is a C 1-4 straight chain,
20-55% of a summed amount of an oxetane crosslinker and an epoxy diluent, 35-45% epoxy functionalized silicon nanoparticles, 1-5% silane adhesion promoter and 0.5-2% photoinitiator.
2. The UV-curable coating composition of claim 1 comprising 5.5-27.5% cycloaliphatic crosslinker, 27.5-49.5% of a summed amount of oxetane crosslinker and epoxy diluent, 39.9% epoxy functionalized silicon nanoparticles, 3.1% epoxy silane adhesion promoter and 2% photoinitiator.
3. The UV-curable coating composition of claim 1 consisting of 5.5-27.5% cycloaliphatic crosslinker, 27.5-49.5% of a summed amount of oxetane crosslinker and epoxy diluent, 39.9% epoxy functionalized silicon nanoparticles, 3.1% epoxy silane adhesion promoter and 2% photoinitiator.
4. The UV-curable coating composition of claim 1 comprising 5.5% cycloaliphatic crosslinker, 24.75% oxetane crosslinker, 24.75% epoxy diluent, 39.9% epoxy functionalized silicon nanoparticles, 3.1% epoxy silane adhesion promoter and 2% photoinitiator.
5. The UV-curable coating composition of claim 1 consisting of 5.5% cycloaliphatic crosslinker, 24.75% oxetane crosslinker, 24.75% epoxy diluent, 39.9% epoxy functionalized silicon nanoparticles, 3.1% epoxy silane adhesion promoter and 2% photoinitiator.
6. The UV-curable coating composition of claim 1 wherein the oxetane crosslinker is bis(1-ethyl-(3-oxetanyl)methyl)ether.
7. The UV-curable coating composition of claim 1 wherein the epoxy diluent is 3-ethyl-3-hydroxymethyl oxetane.
8. The UV-curable coating composition of claim 1 wherein the silicon nanoparticles of the epoxy functionalized silicon nanoparticles are in the range of 5-200 nm.
9. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is selected from an amino functional silane, a ureido functional silane, an epoxy functional silane, a sulfur functional silane, and mixtures thereof.
10. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is an amino functional silane selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, aminophenyltrimethoxysilane, 3-aminopropyltris(methoxyethoxy ethoxy)silane, 3-(m-aminophenoxy)propyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane N-[3-(trimethoxysilyl)propyl]ethlenediamine damosilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(6-aminohexyl)aminomethyl-trimethoxysilane, N-(2-aminoethyl)-11-aminoundecyl-trimethoxysilane, (aminoethylaminomethyl)phenethyl-trimethoxysilane, N-3-[(amino(polypropyleneoxy)]aminopropyltrimethoxysilane, (3-trimethoxysilylpropyl)diethylene triamine, (3-trimethoxysilylpropyl)diethylene-triaminesilane, N-phenylaminopropyltrimethoxysilane, N-phenylaminomethyltriethoxysilane, bis(trimethoxysilylpropyl)aminesilane, bis[(3-trimethoxysilyl)propyl]-ethylenediaminesilane, bis[3(triethoxysilyl)propyl]ureasilane and mixtures thereof.
11. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is a ureido functional silane selected from the group consisting of ureidopropyltriethoxysilane, ureidopropyltrimethoxysilane and mixtures thereof.
12. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is an epoxy functional silane selected from the group consisting of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, (3-glycidoxypropyl)trimethoxysilane 3-(2,3-epoxypropoxy)propyltrimethoxysilane, (3-glycidoxypropyl)triethoxysilane, 5,6-epoxyhexyltriethoxysilane and mixtures thereof.
13. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is a sulfur functional silane selected from the group 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis-N—N′-(triethoxysilylpropyl)aminocarbonylpolyethylene oxide, bis-(3-(triethoxysilylpropoxy)-2-hydroxypropoxy)-polyethylene oxide, N—N′-(bis(2-hydroxyethyl)-N,N′bis(3-trimethoxysilylpropyl)ethylene-diamine, and mixtures thereof.
14. The UV-curable coating composition of claim 1 wherein the silane adhesion promoter is 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane or a mixture thereof.
15. The UV-curable coating composition of claim 1 wherein the photoinitiator is triarylsulfonium hexafluoroantimonate.
16. The UV-curable coating composition of claim 1 wherein the viscosity of the composition is stable in the range of −20° C. to 40° C.
17. A process for modifying the surface of a substrate comprising applying to the surface a UV-curable coating comprising (in weight %) 5-50% cycloaliphatic crosslinker of the formula
wherein R is
wherein X is a C 1-4 straight chain,
20-55% of a summed amount of an oxetane crosslinker and an epoxy diluent, 35-45% epoxy functionalized silicon nanoparticles, 0-5% silane adhesion promoter and 0.5-2% photoinitiator, and curing the surface using ultraviolet radiation.
18. The process of claim 17 , further comprising thermally curing the surface.
19. The process of claim 17 wherein the UV-curable coating is operable to provide a modified surface having an indentation threshold fracture load of at least 30 Kgf.
20. The process of claim 17 comprising applying the UV-curable coating to a non-strengthened glass surface.
21. The process of claim 17 wherein the substrate comprises a non-strengthened glass surface and a strengthened glass surface, and the process comprises applying the UV-curable coating to at least the non-strengthened glass surface to increase the indentation threshold fracture load of the non-strengthened glass surface to at least 30 Kgf.
22. The process of claim 17 , wherein the substrate comprises glass.
23. The process of claim 17 , further comprising applying silane adhesion promoter to the surface of the substrate.
24. An article comprising a substrate and a coating on a surface of the substrate wherein the coating comprises (in weight %) 5-50% cycloaliphatic crosslinker of the formula
wherein R is
wherein X is a C 1-4 straight chain,
20-55% of a summed amount of an oxetane crosslinker and an epoxy diluent, 35-45% epoxy functionalized silicon nanoparticles, 1-5% silane adhesion promoter and 0.5-2% photoinitiator.
25. The article according to claim 24 wherein the surface comprising the coating comprises an indentation threshold fracture load of at least 30 Kgf.
26. The article according to claim 24 wherein the substrate comprises glass.
27. The article according to claim 24 wherein the substrate comprises a non-strengthened glass surface and a strengthened glass surface and the UV-curable coating is disposed on at least the non-strengthened glass surface.