Multilayer coating
View Patent ↗The present invention relates to a multilayer coating in which a plurality of photocurable resin cured films are layered on a substrate, wherein at least two adjacent layers comprise the same hindered phenol-type antioxidant. The multilayer coating can be applied onto a substrate, such as glass fibers, vinyl chloride sheets, polycarbonate sheets, glass plates, polyethylene films, wood, acrylic sheets, metal plates, and the like.
1. A multilayer coating in which a plurality of photocurable resin cured films are layered, wherein at least two adjacent layers comprise the same hindered phenol antioxidant in different amounts, and wherein the antioxidant has at least one hindered phenol group, said hindered phenol group containing none or only one sterically hindered alkyl group selected from the group consisting of an i-propyl group, an i-butyl group, and a tert-butyl group and wherein said adjacent layers comprise urethane meth(acrylate),
wherein said multilayer coating further comprises an amine compound;
wherein said amine compound is present in said multilayer coating to prevent the generation of hydrogen gas.
2. The multilayer coating according to claim 1 , wherein the antioxidant is present in the at least two layers in amounts ranging from 0.01 to 4 wt %.
3. The multilayer coating according to claim 2 , wherein the amounts range from 0.01 to 3 wt %.
4. The multilayer coating according to claim 1 , wherein the at least one hindered phenol group contains only one sterically hindered alkyl group selected from the group consisting of an i-propyl group, an i-butyl group, and a tert-butyl group.
5. The multilayer coating according to claim 1 , wherein the antioxidant is a compound having a group shown by the following formula (1)
6. The multilayer coating according to claim 1 , wherein the antioxidant is a compound shown by the following formula (2):
wherein R represents a divalent organic group consisting of carbon atoms, hydrogen atoms, and oxygen atoms containing a hydrocarbon chain having two or more carbon atoms and an ester structure.
7. The multilayer coating according to claim 1 , wherein the coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
8. The multilayer coating according to claim 1 , wherein the coating exhibits a ΔYI, the difference in YI due to 4 days exposure of the coating at 23° C. and 50% RH by fluorescent light, of less than 3.
9. A substrate coated with the multilayer coating according to claim 1 , said substrate being selected from the group consisting of an optical glass fiber, optical plastic fiber, optical fiber ribbon, glass plate for a liquid crystal panel, plastic lens, a polycarbonate sheet, vinyl chloride floor material, and wood material for furniture.
10. A coated optical fiber comprising a glass fiber and a multilayer coating applied thereon, said multilayer coating comprising a primary coating and a secondary coating as adjacent layers, wherein the multilayer coating is a coating according to claim 1 .
11. An optical fiber ribbon comprising at least two coated optical fibers according to claim 10 and a matrix material in which the optical fibers are encapsulated.
12. The multilayer coating according to claim 6 , wherein the antioxidant is 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane or triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate].
13. The multilayer coating according to claim 12 , wherein the antioxidant is present in the at least two layers in amounts ranging from 0.01 to 4 wt %.
14. The multilayer coating according to claim 12 , wherein said coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
15. The multilayer coating according to claim 12 , wherein said coating exhibits a ΔYI of less than 3 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
16. The multilayer coating according to claim 1 , wherein said hindered phenol group contains no tert-butyl group.
17. The multilayer coating according to claim 16 , wherein said antioxidant has the following formula:
wherein R a is an alkyl group having 1-4 carbon atoms, and R b and R c are alkyl groups having 5-12 carbon atoms.
18. The multilayer coating according to claim 17 , wherein said coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
19. The multilayer coating according to claim 17 , wherein said coating exhibits a ΔYI of less than 3 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
20. The multilayer coating according to claim 17 , wherein said antioxidant is 4,6-bis(octylthiomethyl)-o-cresol.
21. A multilayer coating in which a plurality of photocurable resin cured films are layered, wherein at least two adjacent layers comprise the same hindered phenol antioxidant in different amounts, and wherein the antioxidant has at least one hindered phenol group, said hindered phenol group containing none or only one sterically hindered alkyl group selected from the group consisting of an i-propyl group, an i-butyl group, and a tert-butyl group and wherein said adjacent layers comprise urethane meth(acrylate),
wherein the antioxidant is present in the at least two layers in amounts ranging from 0.01 to 4 wt %, and
wherein said multilayer coating comprises an amine compound;
wherein said amine compound is present in said multilayer coating to prevent the generation of hydrogen gas.
22. The multilayer coating according to claim 21 , wherein the amounts range from 0.01 to 3 wt %.
23. The multilayer coating according to claim 21 , wherein the at least one hindered phenol group contains only one sterically hindered alkyl group selected from the group consisting of an i-propyl group, an i-butyl group, and a tert-butyl group.
24. The multilayer coating according to claim 21 , wherein the antioxidant is a compound having a group shown by the following formula (1)
25. The multilayer coating according to claim 21 , wherein the antioxidant is a compound shown by the following formula (2):
wherein R represents a divalent organic group consisting of carbon atoms, hydrogen atoms, and oxygen atoms containing a hydrocarbon chain having two or more carbon atoms and an ester structure.
26. The multilayer coating according to claim 21 , wherein the coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
27. The multilayer coating according to claim 21 , wherein the coating exhibits a ΔYI, the difference in YI due to 4 days exposure of the coating at 23° C. and 50% RH by fluorescent light, of less than 3.
28. A substrate coated with the multilayer coating according to claim 21 , said substrate being selected from the group consisting of an optical glass fiber, optical plastic fiber, optical fiber ribbon, glass plate for a liquid crystal panel, plastic lens, a polycarbonate sheet, vinyl chloride floor material, and wood material for furniture.
29. A coated optical fiber comprising a glass fiber and a multilayer coating applied thereon, said multilayer coating comprising a primary coating and a secondary coating as adjacent layers, wherein the multilayer coating is a coating according to claim 21 .
30. An optical fiber ribbon comprising at least two coated optical fibers according to claim 29 and a matrix material in which the optical fibers are encapsulated.
31. The multilayer coating according to claim 25 , wherein the antioxidant is 3,9-bis[2- {3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane or triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate].
32. The multilayer coating according to claim 31 , wherein the antioxidant is present in the at least two layers in amounts ranging from 0.01 to 4 wt %.
33. The multilayer coating according to claim 31 , wherein said coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
34. The multilayer coating according to claim 31 , wherein said coating exhibits a ΔYI of less than 3 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
35. The multilayer coating according to claim 21 , wherein said hindered phenol group contains no tert-butyl group.
36. The multilayer coating according to claim 35 , wherein said antioxidant has the following formula:
wherein R a is an alkyl group having 1-4 carbon atoms, and R b and R c are alkyl groups having 5-12 carbon atoms.
37. The multilayer coating according to claim 36 , wherein said coating exhibits a YI of less than 7 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
38. The multilayer coating according to claim 36 , wherein said coating exhibits a ΔYI of less than 3 after 4 days of fluorescent light exposure at 23° C. and 50% RH.
39. The multilayer coating according to claim 36 , wherein said antioxidant is 4,6-bis(octylthiomethyl)-o-cresol.
40. The multilayer coating of claim 1
wherein a first layer of said at least two adjacent layers comprises 0.3% of a first antioxidant with at least one hindered phenol group;
wherein a second layer of said at least two adjacent layers comprises 3% of a second antioxidant with at least one hindered phenol group; and
wherein said first antioxidant and said second antioxidant are the same.
41. The multilayer coating of claim 21
wherein a first layer of said at least two adjacent layers comprises 0.3% of a first antioxidant with at least one hindered phenol group;
wherein a second layer of said at least two adjacent layers comprises 3% of a second antioxidant with at least one hindered phenol group; and
wherein said first antioxidant and said second antioxidant are the same.