Retention and drainage aid for papermaking
CA 1324703 C · Owner: Eka Chemicals (Ac) Limited · Inventors: Rushmere, John Derek
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improvement in a papermaking process in which an aqueous paper furnish containing cellulosic pulp, and optionally also mineral fillers is formed and dried, the improvement being the addition of a drainage and retention aid comprising a water soluble alkali metal polyaluminosilicate microgels formed from the reaction of polysilicic acid and an alkali metal aluminate, the polyaluminosilicate having an alumina/silica mole ratio greater than about 1/100 together with a cationic polymer selected from the group consisting of cationic starch, cationic guar and cationic polyacrylamide.
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 November 30, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 30, 2010.
- 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.