Process for electrolytically treating aluminium and aluminium alloys
CA 2029438 C · Owner: Sandoz Ltd. · Inventors: Patel, Pinakin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for providing a variety of light to medium colours of anodised aluminium or aluminium alloys which comprises the steps of anodising an aluminium or aluminium alloy workpiece in an aqueous strong acid electrolyte solution by application of direct current to form on the workpiece a porous anodic oxide film having a thickness of at least about 3 microns; subjecting the resulting anodised workpiece to alternating current in an aqueous strong acid electrolyte solution comprising an organic carboxylic acid containing at least one reactive group bound to the carbon atom in the alpha-position; and electrolytically colouring the workpiece. In a preferred embodiment resulting in deepened …
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 7, 1990 and granted October 2, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 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.