Method for pickling iron and steel surfaces
CA 2027294 A1 · Owner: Hakansson, Lars A. H. · Inventors: Hakansson, Lars A. H.; Hakansson, Lars A. H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method for pickling and/or etching icon and steel surfaces, in which the surfaces are treated in a pickling bath which contains inhibitors mineral acids and metal salts of the anions of the acids. The method is characterized in that the inhibitor used is a mixture of tensides, silicates, phosphates and possibly oils, and in that the surfaces are preferably coated with inhibitor prior to being treated in the pickling bath. The surfaces are preferably first degreased with an aqueous tenside solution, therewith to emulsify hydrocarbons such, as grease and oils. Growth of microorganisms is stimulated for biological degradation of the hydrocarbons by adding, nutrient …
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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 October 10, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 10, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 10, 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.