| abstract |
Reinforced silicone elastomers, having improved tensile strength and particularly tear strength, include at least copolymers of aryl siloxanes and alkyl siloxanes, in a ratio of aryl to alkyl substituents providing 6 to 16 mole percent phenyl chosen to provide a refractive index matched to the index of refraction of a silica filler, form optically clear material useful for soft contact lenses. Preferably two copolymers are used and each has methyl groups with 6 to 16 mole percent phenyl groups. One of the two copolymers contains terminal vinyl groups and the other copolymer contains terminal (R)2HSi-O- groups. Platinum materials are used to catalyze the vulcanization of the copolymer mix. These elastomers are useful for a variety of optical products, e.g., contact lenses, intraocular implants and the like. |