Filler on silicon dioxide base, process for its manufacture and use
CA 2202936 C · Owner: Heraeus Kulzer Gmbh · Inventors: Erdrich, Albert; Heindl, Detlef
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Porous silicon dioxide glass with a particle size of 0.5-50 µm a pore size of, 20-120 nm, a pore volume of 200-1000 mm3/g and a BET surface of 10-100 m2/g is suggested as an inorganic filler for polymerizable materials. Polymeric products containing this filler are characterized by very good abrasion resistance.
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 April 17, 1997 and granted June 12, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 17, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 17, 2019.
- 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.