Powdered superabsorbents, containing silica, their preparation process and their use
CA 2045425 C · Owner: Mallo, Paul · Inventors: Mallo, Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Hydrophilic, powdered superabsorbents which are insoluble in water, containing by weight, in the dry state in, combination, from 1 to 45% of colloidal silica with an average diameter of non-agglomerated particles comprised between 9 and 50 nm and 99 to 55% of a cross-linked polymer based on free acrylic acid, partially or totally salified by a sodium or potassium, preparation process and use notably for the absorption of aqueous fluids.
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 June 25, 1991 and granted May 30, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 25, 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.