Modification of starch
CA 2195498 C · Owner: Johansson, Hans · Inventors: Johansson, Hans; Larsson, Ake; Lund, Tomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for modification of cationic starch at which the cationic starch is treated in the presence of water, with an aluminium compound. The modified cationic starch is useful as a retention agent. The invention also relates to a method for improving retention and/or dewatering in papermaking at which cationic starch is modified by the process.
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 January 20, 1997 and granted October 3, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 20, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 20, 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.