Titanium dioxide aggregates, process for producing same and electrophotographic photosensitive material containing same
CA 2006729 C · Owner: Ishihara Sangyo Kaisha, Ltd. · Inventors: Murasawa, Sadao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides novel titanium dioxide aggregates especially suitable for an electrophotographic photosensitive material. This titanium dioxide aggregates comprise sintered aggregates of fine primary particles and have a rutile type crystal structure and an oil absorption of 35-65. This titanium dioxide aggregates which are treated with a mineral acid is also provided. There is also provided an electrophotographic photosensitive material which contains such titanium dioxide in a photosensitive layer.
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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 December 27, 1989 and granted July 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 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
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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.