Polyvinyl alcohol derivatives containing pendant vinylic monomer reaction product units bound through ether groups and hydrogel contact lenses made therefrom
CA 1330674 C · Owner: Ciba Specialty Chemicals Holding Inc. · Inventors: Goldenberg, Merrill
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyvinyl alcohol derivatives containing pendant vinylic monomer reaction product units bound through ether groups and hydrogel contact lenses made therefrom, Abstract, A contact lens of a crosslinked organic aprotic solvent insoluble, substantially transparent polymer of a derivative of a polyvinyl alcohol having a weight average molecular weight of at least about 2,000 containing an effective amount between about 0.1 and 90 percent based on, the number of hydroxyl groups on said polyvinyl alcohol of a crosslinked, addition reaction product of units of the formula (I), in the presence or absence of a polymerizable vinylic monomer wherein R1 is a divalent aliphatic, cycloaliphatic aryl, …
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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 July 12, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 12, 2011.
- 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.