Hydrophilic copolymers
CA 1080888 A · Owner: Contact Lenses (Manufacturing) Limited · Inventors: Mikucki, Wiktor; Cordrey, Philip W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A hydrophilic copolymer suitable for contact lenses consisting essentially of copolymerised N-vinyl-2-pyrrolidone and methyl methacrylate in a molar ratio of from about 6:1 to about 1:1 and including (i) a minor amount of at least one cross-linking agent containing at least two olefinic bonds per molecule and (ii) a minor amount of an ethylene oxide - propylene oxide block copolymer having a molecular weight of not more than about 6,000.
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
- Granted July 1, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 1, 1997.
- 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.