Stable blend of ketene dimer size and colloidal silica
CA 2092955 C · Owner: Dasgupta, Sunil P. · Inventors: Dasgupta, Sunil P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A composition containing a ketene dimer size for sizing paper that is a stable aquasol of positively charged colloidal silica, positively charged colloidal alumina or positively, charged colloidal zirconia and also contains the ketene dimer, and a method for sizing a paper product of sheeted cellulosic fibers comprising treating the fibers with the said composition are disclosed.
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 March 30, 1993 and granted January 12, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2015.
- 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.