Process for the hydrothermal production of potassium silicate solutions
CA 2069489 C · Owner: Cognis Deutschland Gmbh & Co. Kg · Inventors: Hoff, Alfred; Schuertz, Jost; Novotny, Rudolf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns a process for the hydrothermal production of potassium silicate solutions with high SiO2 mol ratios by the hydrothermal reaction of quartz sand with aqueous potassium hydroxide solutions in the range from 150 to 300 °C and the pressures of satured water vapour corresponding to these temperatures in a pressure reactor, in which the potassium silicate solutions thus-obtained, which have SiO2;K2O mol ratios of less than 2.75:1, are then converted with a quartz tempered at temperatures in the range from over 1100 °C to the melting point, whereby the temperatures and pressures are also kept within the aforementioned ranges.
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 November 14, 1990 and granted February 13, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 14, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 14, 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.