摘要 |
<p>This invention provides novel compositions curable to resins and particularly provides oxygen permeable, inherently wettable optical devices useful as eye contact or intraocular lenses. The lenses are composed of a cured polysiloxane resin having an advancing water-in-air contact angle of no greater than 80 DEG . The polysiloxane resin is prepared from a catalyzed mixture of an acrylate-functional polysiloxane composition and an organosilicon cross-linking agent containing silicon hydride radicals. The acrylate-functional polysiloxane composition contains a sufficient amount of aliphatically unsaturated hydrocarbon radicals (e.g., vinyl radicals) other than acrylate-functional radicals to enable that composition to react on a mole to mole basis with the cross-linking agent to produce a cured polysiloxane resin. To provide the desired level of surface wettability, the acrylate-functional polysiloxane composition also contains an effective amount, typically from 7 to 30 mole percent of the total moles of siloxane units present in the cured polysiloxane resin, of H2C=CRCOOR'SiO1.5 units to provide the aforementioned advancing water-in-air contact angles. The catalyzed mixture only contains a sufficient amount of cross-linking agent to react with the aliphatically unsaturated hydrocarbon radicals other than the acrylate-functional radicals and thus enables the unreacted acrylate-functional siloxane units to provide the desired wettability characteristics to the cured polysiloxane resin.</p> |