Dispersions
CA 2078596 C · Owner: Imperial Chemical Industries Plc · Inventors: Tapley, Carole A. M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An oil dispersion which is substantially transparent to visible light comprises an oil, particles of zinc oxide having an average size of from 0.005 to 0.15 micron and an organic dispersing agent. The solids content of the dispersion is at least 30 weight per cent its extinction coefficients at 308 nm(E(308)) and 360 nm (E(360)) wavelengths are both at least 9 litres per gram percentimetre and the ratio E(360):E(308) is in the range 0.75:1 to 1.5:1. A method of preparing the dispersion is also described in which the ingredients are milled together in the presence of a particulate grinding mediumuntil the required particle size and optical properties are obtained. The dispersions are useful …
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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 18, 1992 and granted May 5, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 18, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 18, 2014.
- 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.