Tinted contact lenses and a method for their preparation
CA 1190708 A · Owner: Novartis Ag · Inventors: Su, Kai C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Tinted contact lenses and a method for their preparation Contact lenses comprising polymeric lens materials in which reactive dyestuffs have been covalently bonded to monomer units of the polymer backbone, said dyestuffs being reactive dyes capable of forming ether linkages with cellulose, and being reactive with hydroxyl amino, amido, or mercapto groups present in a hydrogel polymer to form the covalent bond therewith. The invention is of particular interest in the area of "soft" contact lenses (hydrogel lenses).
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 23, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 23, 2002.
- 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.