Black chromium plating bath useful for solar selective coatings
CA 2006130 C · Owner: Rajagopal, Indira · Inventors: Rajagopal, Indira; Grips, Vatia Krishnamurthy William; Rajagopalan, Sundarapandiun Rama
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The composition disclosed is an improved black chromium plating bath useful, for example, for solar selective coatings. The bath comprises an aqueous solution of sulphate-free chromic acid containing nitrate, borate and fluorosilicate ions. Such a bath can be employed at room temperature or higher e.g. in the temperature range 30°C to 50°C and at a low current density e.g. 0.07 to 0.28 A cm2,to obtain a good quality black chromium deposit which is quite coherent and has a high absorptivity to emissivity ratio e.g. about 8 .
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 December 20, 1989 and granted May 12, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2011.
- 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.