Hyperplaty clays and their use in paper coating and filling, methods for making same, and paper products having improved brightness
CA 2920439 C · Owner: Imerys Usa, Inc. · Inventors: Wesley, Robin; Garska, Michael J.; Jones, Philip J. E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a hydrous kaolin product having improved optical properties for example, when used in the production of paper products. The present invention comprises an improved barrier coating for paper and a method of making the coated paper. The present invention also comprises an improved method from making filled and coated paper products. The present invention uses a composition comprising kaolin having a shape factor of at least about 70:1 such as at least about 80:1 or at least about 100:1.
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 September 6, 2002 and granted January 7, 2020. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 6, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 6, 2024.
- 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.