Use of imidazole-2-thione as complexing agent in displacement tin plating
CA 2083197 C · Owner: Vitale, Americus C. · Inventors: Vitale, Americus C.; Arduengo, Anthony J. Iii; Dodd, John R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An environmentally innocuous effective replacement for thiourea is disclosed for use as a complexing agent in displacement plating processes in which the plating solution is applied to the substrate surface to be plated by immersion or by spraying, cascading, pouring and the like. The replacement complexing agent is an unsymmetrical dialkylimidazole-2-thione compound having the formula: (see fig. I), wherein A is methyl or ethyl and when A is methyl, B is a, C3 to C6 alkyl or cycloalkyl group and when A is ethyl, B, is a C4 to C6 alkyl or cycloalkyl group. Of this class of compounds, 1-methyl-3-propyl-2-thiocarbonyl-2,3-dihydroimidazole is preferred for immersion tin plating. This class of …
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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 November 18, 1992 and granted January 6, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 18, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 18, 2014.
- 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
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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.