Organic photochromic pigment
CA 1331666 C · Owner: Hoelscher, Charles H. · Inventors: Haynes, Ronald L.; Lasch, Jonathan G.; Hoelscher, Charles H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Described is photochromic particulate material comprising a photochromic substance within a matrix of a polymerizate of a polyfunctional acrylate monomer. The photochromic particulate material may be produced by adding an organic photochromic substance to a polymerizable composition including a polyfunctional acrylate monomer and polymerizing the resultant admixture, e.g. by emulsion polymerization. in the case of emulsion or suspension polymerization finely divided, particulate organic photochromic materials are separated from the polymerization medium in the form of spheroidal thermoset photochromic particles of fairly uniform size. If desired the particles recovered, from the …
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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
- Granted August 23, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 23, 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.