Abrasion-resistant tintable coating
View Patent ↗A curable coating composition includes: a) at least one monomer chosen from polyol poly(meth)acrylate monomers having from 3 to 6 (meth)acrylate functions, b) at least one monomer chosen from polyol polyglycidyl ethers having at least three epoxy functions, c) at least one difunctional monomer, d) at least one free-radical photo-initiator, and e) at least one cationic photo-initiator, wherein the molar ratio of acrylate equivalents to epoxy equivalents in the composition ranges from 3:1 to 4:1, and wherein the composition is free of silica and of monomers bearing a silane function. A method for coating a substrate, such as an ophthalmic lens, with this composition, and the coating substrate thus obtained are also disclosed.
1. A curable coating composition comprising:
a) at least one monomer chosen from polyol poly(meth)acrylate monomers having from 3 to 6 (meth)acrylate functions,
b) at least one monomer chosen from polyol polyglycidyl ethers having at least three epoxy functions,
c) at least one difunctional monomer,
d) at least one free-radical photo-initiator, and
e) at least one cationic photo-initiator,
wherein the molar ratio of acrylate equivalents to epoxy equivalents in the composition ranges from 3:1 to 4:1,
and wherein the composition is free of silica and monomers bearing a silane function.
2. The composition according to claim 1 , wherein the polyol poly(meth)acrylate monomer is selected from the group consisting of: pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate and their mixtures.
3. The composition according to claim 1 , wherein the polyol polyglycidyl ether is a polyol triglycidyl ether.
4. The composition according to claim 3 , wherein the polyol polyglycidyl ether is trimethylolpropane triglycidyl ether.
5. The composition according to claim 1 , wherein the difunctional monomer comprises at least one polyol di(meth)acrylate, at least one polyol diglycidyl ether, or a mixture thereof.
6. The composition according to claim 5 , wherein the difunctional monomer is selected from the group consisting of polyol di(meth)acrylates.
7. The composition according to claim 6 , wherein the difunctional monomer comprises two polyol di(meth)acrylates, at least one of which is an alkanediol di(meth)acrylate and at least one of which is a polyethyleneglycol di(meth)acrylate.
8. The composition according to claim 7 , wherein the difunctional monomer comprises a mixture of 1,6-hexanediol diacrylate with at least one polyethyleneglycol di(meth)acrylate having at least three ethylene glycol units.
9. The composition according to claim 1 , wherein the weight ratio of the total amount of polyol poly(meth)acrylate monomers, including polyol di(meth)acrylate monomers, to epoxy monomers in the composition ranges from 2:1 to 3:1, preferably from 2.4:1 to 2.6:1.
10. The composition according to claim 1 , which is substantially free of solvent.
11. The composition according to claim 1 , which comprises at least one surfactant, at least one slip agent or a mixture thereof.
12. A method for manufacturing an article, comprising:
a) applying the composition according to claim 1 to at least one surface of a substrate,
b) curing said composition to form a coated surface on said substrate.
13. The method according to claim 12 , which further comprises the step of absorbing at least one dye into said coated surface.
14. A method for treating a substrate, comprising
coating said substrate with a composition according to claim 1 .
15. The method according to claim 12 , wherein the substrate is a finished or semi-finished ophthalmic lens.
16. An article manufactured according to the method of claim 12 .
17. The method according to claim 13 , wherein the substrate is a finished or semi-finished ophthalmic lens.
18. An article manufactured according to the method of claim 13 .