Amorphous silica-alumina spherical particles and process for preparation thereof
CA 2011038 C · Owner: Mizusawa Industrial Chemicals, Ltd. · Inventors: Ogawa, Hiroshi; Abe, Kiyoshi; Suzuki, Kazuhiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are amorphous silica-alumina spherical particles having a notched surface. The particles have a small specific surface area and a highly controlled hygroscopic property. The spherical particles are obtained by exchanging at least a part of an alkali metal ion of a P-type zeolite as the starting material with a divalent metal and firing the ion-exchanged zeolite. Since the pH value is shifted to a weakly alkaline level by the ion exchange treatment the, particles are effective as a filler for stabilizing a resin or the like when incorporated therein and the, refractive index of the particles can be made close to that of a resin in which the particles are to be incorporated.
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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 February 27, 1990 and granted September 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 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.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.