Composite pigmentary material
CA 2098323 A1 · Owner: Melville, Iain Anderson · Inventors: Rauch, Robert; Melville, Iain Anderson
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A new process for preparing a composite pigment from titanium dioxide and calcium sulphate is provided in which the calcium sulphate is milled to a particle size less than 10 microns mixed with titanium dioxide, and the mixed particulates are coated with an oxide or hydrous oxide of a metal or silicon. The process can particularly be employed in conjunction with a sulphate-process titanium dioxide plant in which by-product sulphuric acid is converted to gypsum. The composite pigment shows improved optical properties in comparison to a mixture of titanium dioxide and gypsum.
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 June 14, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 14, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 14, 2015.
- 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.