Swollen starch compositions for use in papermaking
CA 2671973 C · Owner: Pulp And Paper Research Institute Of Canada · Inventors: Laleg, Makhlouf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A novel filler treatment comprising the preparation of swollen starch compositions, more especially ionic starch compositions prepared in the , presence or , absence of co-additives and the addition of the said composition to a filler suspension, has been developed. Use of the treated filler during papermaking improves filler retention and produces filled papers where addition of the filler has , only a minimal negative effect on strength properties. The swollen starch compositions can be prepared in a batch or jet cooker or by mixing with hot , water , under controlled conditions (i.e. temperature pH, mixing, mixing time) in , order to make the starch granules swell sufficiently to …
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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 April 7, 2003 and granted February 26, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 7, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2025.
- 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.