Powder colorant compositions and process for the preparation thereof
CA 2093210 C · Owner: Henry, James William · Inventors: Krutak, James John; Oldfield, Terry Ann; Parham, William Whitfield
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are powder colorant compositions in a finely-divided form and processes for the preparation therefor. The colorant compositions are comprised of a semicrystalline polyester, in finely-divided form having copolymerized therein one or more colorant compounds at levels greater than about 1 weight percent. The process for preparing these compositions involves the dissolution of an amorphous polyester concentrate in a crystallization-inducing solvent (s) followed by, crystallization. Such compositions are useful as pigments or colorants where nonextractability of the colorant is important.
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 October 28, 1991 and granted February 4, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 28, 2013.
- 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.