Process for producing plastic lens
CA 2061602 C · Owner: Mase, Shoji · Inventors: Otani, Noboru; Mase, Shoji; Yoshida, Motoaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing a plastic lens which, comprises;, (1) applying a primer coating composition composed mainly from a blocked polyisocyanate and a polyol onto a surface of a plastic lens substrate and heating the primer coating composition to form a primer layer of a thermoset polyurethane, the blocked polyisocyanate being a polyisocyanate blocked with a .beta.-diketone, (2) forming a hard coating layer on the primer layer, and, (3) vapor-depositing an inorganic material or inorganic materials on the hard coating layer to form a single-layered or multi-layered anti-reflection coating.
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 February 20, 1992 and granted October 17, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 20, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 2014.
- 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.