Inorganic hydrogel flatting agents
CA 2008463 C · Owner: Schmidt, Stephen Raymond · Inventors: Schmidt, Stephen Raymond; Welsh, William Alan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved flatting agent comprising an inorganic hydrogel having a pore volume of at least 1.0 ml/g an, average particle size in the range 1 to 10 microns and a, particle size distribution such that when the flatting agent is dispersed in a coating, the fineness of grind is at least 4.75 on the Hegman scale. The inorganic hydrogel flatting agents of this invention are prepared by milling an inorganic hydrogel under controlled temperature conditions wherein a volatile content of at least 40 weight percent is maintained, to produce inorganic hydrogel particles characterized by a pore volume of at least 1.0 ml/g, an average particle size in the range of 1 to 10 microns, and a particle size …
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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 January 24, 1990 and granted April 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 24, 2012.
- 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.