Polymeric compositions for oxygen permeable contact lenses
CA 2027748 C · Owner: Rothenberger, Scott D. · Inventors: Baron, Richard C.; Rothenberger, Scott D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Carboxylic acid esters devoid of beta hydrogens are homopolymerized or copolymerized with contact lens organic materials to form desirable contact lens materials and contact lenses. These materials have good contact lens properties, including desirable DK values, hardness, machineability and a desirable refractive index of at least 1.
Read the whole patent
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
- Filed October 16, 1990 and granted January 6, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 16, 2012.
- 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
Timeline From CIPO dates
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.