Cryogenic polishing method for soft acrylic articles
CA 2269029 C · Owner: Alcon Laboratories, Inc. · Inventors: Sheets, John W. Jr.; Lewellen, Kevin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for polishing articles comprising soft acrylic materials is disclosed. The method includes a cryogenic polishing step and a cleaning step. In the polishing step, a receptacle is charged with polishing beads of various sizes, sodium bicarbonate a swelling agent and, the articles to be polished for a period of time and at a rotation speed sufficient to remove surface irregularities. Following the polishing step, a receptacle is charged with (a) a cleaning slurry comprising cleaning beads of various sizes and (i) sodium hydroxide and water or (ii) alumina, a surfactant and a solvent and (b) the articles to be cleaned for a period of time and at a rotation speed sufficient to clean …
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 October 31, 1997 and granted December 23, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 31, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 31, 2019.
- 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.