Thermochromic ink formulations, nail lacquer and methods of use
CA 2201397 C · Owner: Small, Lyle D. · Inventors: Small, Lyle D.; Highberger, Gerald
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention comprises a series of discoveries related to the problems associated with formulations that destroy the color change properties of thermochromic encapsulated dyes. One aspect of the present invention is the discovery of a method of correcting these formulations to allow the addition of thermochromic dyes. Certain solvents destroy the dye therefore any , aldehydes, ketones, and diols and most aromatic compounds should be removed from the formulation and if needed they should be replaced with solvents preferably having a large molecular weight (i.e. greater than 100 and low reactivity). Secondly, the formulation should be adjusted to be neutral (i.e. 6.5-7.5 pH) …
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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 September 29, 1995 and granted July 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 29, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 29, 2017.
- 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.