Coating composition and optical mar-resistant tintable coating
A coating composition and coating for ophthalmic lenses and other polymeric substrates having a unique combination of excellent solution stability, rapid cure rate, improved mar resistance, rapid dye absorption, and improved receptivity towards antireflective coatings. The coating comprises an abrasion resistant polymer and a dye-absorption-enhancing oligomer. The coating is tinted after curing with a dye to provide light absorbency in the coating.
1 . A coating composition comprising:
a) at least one organofunctional trialkoxysilane monomer in the amount of from 20 to 80 percent by weight, said trialkylsiloxane monomer having the formula;
where R 1 , R 2 , and R 3 are independently selected from alkyl groups of 1 to 8 carbon atoms;
n is an integer 1 through 6, inclusive,
and X is selected from the group consisting of glycidyl, acrylate, methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, vinyl, and allyl;
b) water to hydrolyze at least one third of alkoxy groups of the trialkoxysilane monomer; and
c) from 1.0 to 25.0 percent by weight at least one oligomeric tintability enhancer.
2 . The coating composition of claim 1 wherein the oligomeric tintability enhancer has a solubility for at least one disperse dye that so that the disperse dye is at least 5× more by weight absorbed into the dye-absorbing enhancer than the same disperse dye is absorbed by a polymer consisting of units derived from the organofunctional trialkoxysilane under dye-tinting absorption conditions of immersion in a hot (95° C.) aqueous solution with at least 0.2% by weight dye/water.
3 . The coating composition of claim 1 wherein the oligomeric tintability enhancer i selected from the group consisting of polyester polyol, urethane polyol, acrylic polyol, and acrylated polyurethane.
4 . The composition of claim 2 further comprising:
d) from 1.0 to 10.0 percent by weight one or more photoinitiators independently selected from the free radical and cationic photoinitiators.
5 . The composition of claim 2 further comprising an organic solvent.
6 . The composition of claim 3 further comprising one or more surfactants or wetting agents are present ion an amount between 0.1 and 15% by weight of the total composition.
7 . The composition of claim 2 wherein the trialkoxysilane comprises an epoxy-trialkoxy silane.
8 . The composition of claim 2 further comprising at least 1% by weight of a diacrylate monomer in the composition.
9 . The composition of claim 1 wherein the trialkoxysilane is reactive with the oligomeric tintability enhancer during polymerization of the trialkoxysilane.
10 . The composition of claim 2 wherein the trialkoxysilane is reactive with the oligomeric tintability enhancer during polymerization of the trialkoxysilane.
11 . The composition of claim 3 wherein the trialkoxysilane is reactive with the oligomeric tintability enhancer during polymerization of the trialkoxysilane.
12 . The composition of claim 4 wherein the trialkoxysilane is reactive with the oligomeric tintability enhancer during polymerization of the trialkoxysilane.
13 . The composition of claim 5 wherein the trialkoxysilane is reactive with the oligomeric tintability enhancer during polymerization of the trialkoxysilane.
14 . An ophthalmic lens having an unpolymerized coating on at least one surface of the lens formed from the coating composition of claim 1 , the polymerized coating having sufficient disperse dye dissolved therein to absorb at least 70% of transmitted light of a wavelength at which the disperse dye has its maximum absorption.
15 . An ophthalmic lens having an unpolymerized coating on at least one surface of the lens formed from the coating composition of claim 2 , the polymerized coating having sufficient disperse dye dissolved therein to absorb at least 70% of transmitted light of a wavelength at which the disperse dye has its maximum absorption and the lens has a relative transmission of between 95% and 100%.
16 . An ophthalmic lens having an unpolymerized coating on at least one surface of the lens formed from the coating composition of claim 3 , the polymerized coating having sufficient disperse dye dissolved therein to absorb at least 70% of transmitted light of a wavelength at which the disperse dye has its maximum absorption.
17 . An ophthalmic lens having an unpolymerized coating on at least one surface of the lens formed from the coating composition of claim 4 , the polymerized coating having sufficient disperse dye dissolved therein to absorb at least 70% of transmitted light of a wavelength at which the disperse dye has its maximum absorption.