Chromium-free composition and process for corrosion resisting treatments for aluminum surfaces
CA 2093923 A1 · Owner: Henkel Corporation · Inventors: Reghi, Gary A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An exceptionally effective chromium free corrosion protective surface treatment composition for aluminum and its alloys is an aqueous acidic liquid comprising water and: (A) from about 0.8 to about 1.2 w/o of H2ZrF6; (B) from about 0.08 to about 0.12 w/o of dispersed silica; (C) from about 0.08 to about 0.12 w/o of a water soluble or dispersible polymer of 3-(N-methyl-N-2-hydroxyethyl-aminomethyl)-4-hydroxystyrene; and (D) from 0.10 - 0.15 w/o of 1-propoxy-2-propanol. The surface to be treated is contacted with the composition and then dried without rinsing. A conventional organic coating may advantageously be applied over the surface produced by this treatment.
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 October 24, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 24, 2013.
- 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.