Dispersion of iron (iii) oxides using certain dihydroxyaromatic compounds
CA 2073658 A1 · Owner: W.R. Grace & Co.-Conn. · Inventors: Kreh, Robert P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for treating an aqueous system which contains solid particles of iron (III) oxide is disclosed which comprises adding to the system catechol hydroquinone, their water soluble salts and mixtures, thereof in an amount effective to disperse or suspend iron (III) oxide particles. The aqueous system should have a pH greater than 7 and have low to moderate hardness.
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 July 10, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 10, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 10, 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.