Process for the preparation of sodium silicates
CA 2061634 A1 · Owner: Hoechst Aktiengesellschaft · Inventors: Kotzian, Michael; Schimmel, Guenther; Tapper, Alexander
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of sodium silicates Abstract:, To prepare crystalline sodium silicates having a laminated structure, a molar ratio of SiO2 to Na2O of (1.9 to 2.1) : 1 and a water content of less than 0.3 % by weight from a water glass solution which has a solids content of at least 20 % by weight and is obtained by reaction of sand with sodium hydroxide solution in a molar ratio of SiO2 : Na2O of (2.0 to 2.3) : 1 the water, glass solution is treated with hot air of 200 to 300°C in a spray drying zone to form a pulverulent amorphous, sodium silicate having a water content (determined as the loss on ignition at 700°C) of 15 to 23 % by weight. The pulverulent, amorphous, …
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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 21, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 21, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 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.