Wettable silicone resin optical devices and curable compositions therefor

As an optical device, a lens to be worn against or inside of the eye, said lens consisting essentially of an optically clear, biocompatible, cured polysiloxane resin having a flexural strength value of at least 3,500 p.s.i. at 21.degree..+-.2.degree. C. in the unhydrated state, an advancing water-in-air contact angle of no greater than 80.degree. at 21.degree..+-.2.degree. C. in the hydrated state and an oxygen gas permeability coefficient of at least 2.times.10.sup.-10 (cm.sup.3.cm)/(cm.sup.2.sec.cm Hg) which results in a calculated open eye Equivalent Oxygen Performance value of at least 3 percent at 0.1 mm thickness at 21.degree..+-.2.degree. C., said resin having been prepared by curing a composition consisting essentially of

• (A) 100 parts by weight of an acrylate-functional polysiloxane composition containing acrylate-functional siloxane units of the unit formula H.sub.2 C.dbd.CROOR'SiO.sub.1.5 where R is a methyl radical or hydrogen and R' is a divalent alkylene radical of from 1 to 4 inclusive carbon atoms and containing siloxane units possessing aliphatically unsaturated hydrocarbon radicals selected from the group consisting of vinyl, allyl and butenylene radicals, the remaining silicon-bonded substituents in addition to divalent oxygen radicals present in said polysiloxane essentially being selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms and phenyl radicals,
• (B) an amount of an organosilicon cross-linking agent containing an average of at least two silicon-bonded hydrogen radicals per molecule, said amount being no greater than that required to provide a 1:1 mole ratio of silicon-bonded hydrogen radicals to total moles of said aliphatically unsaturated hydrocarbon radicals present in (A), essentially any remaining substituents in addition to divalent oxygen radicals present in said agent being selected from the group consisting of alkyl radicals of from 1 to 3 inclusive carbon atoms and phenyl radicals, and
• (C) a catalytic amount of a Group 8 Transition Metal catalyst which preferentially catalyzes the addition of said silicon-bonded hydrogen radicals to said aliphatically unsaturated hydrocarbon radicals instead of the >C.dbd.C<
• portion of the acrylate-functional siloxane units, there being at least a sufficient amount of said aliphatically unsaturated hydrocarbon radicals in (A) such that when the mixture of (A), (B) and (C) is cured to form a resin, said resin possesses the aforementioned flexural strength value, there further being an effective amount of said acrylate-functional siloxane units present in (A) such that the cured resin possesses the aforementioned water-in-air contact angle and is inherently wettable by the tear fluid of a wearer of such a lens and wherein less than 30 mole percent of the total moles of silicon atoms present in (A) and (B) are derived from said acrylate-functional siloxane units.