Process for producing brown covering layers on copper
CA 2054166 C · Owner: Puscasu, Constantin · Inventors: Puscasu, Constantin; Hoveling, Stefan; Protzer, Helmut
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a uniform and adherent brown covering layer (brown patina) on surfaces of semifinished products made of copper, particularly on rolled tapes or sheets used in building construction. The surface of the copper semifinished product is first roughened by means of a mechanical treatment. The copper semifinished product is then heat treated at a temperature lying within the temperature range of 150 to 650°C for the duration of 0.1 to 30 minutes. The copper semifinished product can be advantageously subjected to a chemical postoxidation treatment immediately following the heat 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 and granted August 17, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term 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.