Papers with a high filler material content and high dry strength
CA 2590489 C · Owner: Esser, Anton · Inventors: Esser, Anton; Von Vadkerthy, Tibor Adalbert; Haehnle, Hans-Joachim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method for producing paper paperboard and , cardboard in the presence of an aqueous suspension of components containing fine-particles of filler material. The fine-particle filler materials are covered at least partially with water-soluble amphoteric copolymers. Said method consists in adding to the fibre suspension prior to the formation of , the sheet, and in addition to the aqueous suspension of components containing fine-particles filler material, at least one cationic and/or amphoteric polymer which, as a structural element does not contain any ester unsaturated carboxylic acids with quaternised amino alcohols.
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 December 14, 2005 and granted February 10, 2015. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.