Rare earth-containing zinc phosphate glasses
CA 2017521 C · Owner: Beall, George H. · Inventors: Quinn, Candace J.; Dickinson, James E. Jr.; Beall, George H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention is concerned with the preparation of glasses exhibiting transition temperatures below 450°C working temperatures below 500°C, and exceptional resistance to mild aqueous alkaline solutions consisting essentially, expressed in terms of mole percent on the oxide basis, of:, ZnO 12-55 K2O 0-25, P2O5 28-40 Li2O+Na2O+K2O 10-35 Li2O 0-25 Rare earth metal oxide 1-5, Na2O 0-25 At least two alkali metal oxides will most desirably be present.
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 May 25, 1990 and granted February 19, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 25, 2012.
- 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.