Photocrosslinked polymers
CA 2129461 C · Owner: Muller, Beat · Inventors: Muller, Beat
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a novel process for the manufacture of mouldings especially contact lenses, in which a soluble prepolymer comprising crosslinkable groups is cross-linked in solution and also to mouldings, especially contact lenses obtainable in accordance with that process. The present invention relates also to novel prepolymers that can be used in the process according to the invention especially derivatives of a polyvinyl alcohol having a molecular weight of at least about 2000 that based on the number of hydroxy groups of the polyvinyl alcohol comprise from approximately 0.5 to approximately 80 % of units of formula I wherein R is lower alkylene having up to 8 carbon atoms R1 …
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 August 4, 1994 and granted December 7, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 4, 2016.
- 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.