Optically clear filled silicone elastomers
US3996189A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 1976 |
| Grant date | Dec 7, 1976 |
| Priority date | — |
| Expiry date | Mar 17, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S528/901
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
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).sub.2 HSi--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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.