Surface treatment of soft contact lens
CA 1269810 C · Owner: Bowman, Lyle M. · Inventors: Lin, Shaow B.; Chandrasekaran, S. Kumar; Harvey, Thomas B. Iii
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the treatment of a soft contact lens to increase, its resistance to the deposition thereon and diffusion and accumulation therein of substances which will promote its clouding and discoloration in use, and to improve its mechanical strength includes treating a hydroxyl group-containing acrylic ester soft contact lens or replica with an organi acid anhydride for a sufficient period of time to treat at least a portion of polymer molecules on the outer surfaces, e.g. by esterifying hydroxyl groups on the molecules and facilitating extraction of organic-type impurities. The process is optionally performed in the presence of a medium which partially swells the surface regions of …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 5, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 5, 2007.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.