Porous spherical cellulose acetate particles
CA 1235119 A · Owner: Daicel Chemical Industries, Ltd. · Inventors: Uchida, Manabu; Yamazaki, Kazuhiro; Ohtake, Etsuo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cellulose acetate is formed into porous spherical particles, having an acetylation degree of 49 to 60 %, a particle diameter of 0.05 to 10 mm, a sphericity of 0.7 or larger, a pore volume of 0.4 cc/g or larger and a collapsing strength of 9 kg or higher.
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
- Granted April 12, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 12, 2005.
- 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.