Method for improving powder characteristics
CA 2055800 C · Owner: Itoh, Masakazu · Inventors: Itoh, Masakazu; Iwasaki, Tadashi; Yanagase, Akira
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for improving powder characteristics which comprises adding to 100 parts by weight of a powder obtained by coagulation of a latex of a graft copolymer comprising rubber as the core 0.05-10 parts by weight of hydrophobic microparticles of silica which consists of silicon dioxide obtained by combustion hydrolysis or the aggregate thereof and has an average particle diameter of 1 µm or less and in which the number of silanol groups present on the surface of the microparticles of silica is 2 or less per 100 .ANG. square.
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 November 19, 1991 and granted July 17, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 19, 2013.
- 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.