Multi-layer effect pigment
CA 2512875 C · Owner: Engelhard Corporation · Inventors: Zimmerman, Curtis J.; Fuller, Daniel Stevenson
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multilayer effect pigment includes a transparent substrate a layer of high , refractive index material on the substrate and alternating layers of low , refractive index and high refractive index materials on the first layer the , total number of layers being an odd number of at least three all adjacent , layers differing in refractive index by at least about 0.2 and at least one of the layers having an optical thickness which is different from all of the other layers. The resulting multi-layer effect pigment is not a quarter wave stack.
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 January 12, 2004 and granted June 17, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 12, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 12, 2026.
- 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.