Paper additive composition and method for producing paper using the same
CA 2461629 C · Owner: Tamai, Tetsuya · Inventors: Asakura, Kazumichi; Tamai, Tetsuya; Nakamura, Yasuyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A paper additive composition comprising an amide compound (a) obtained by reacting a polyamine and a carboxylic acid or a salt of the amide compound (a) is provided. The polyamine is shown by formula (1):, R-(NH-R1)n-NH2 (1), (wherein R is H2N-R1 or R2 and each R1 is independently an alkylene group having 1 to 4 carbon atoms, R2 is an alkyl group or alkenyl group having 12 to 22 carbon atoms, and n is an integer of 1 to 3); the number of carbon atoms of the carboxylic acid is 10 to 24; the amide compound is obtained by reacting the carboxylic acid in a ratio of 0.5 to 4.3 moles per 1 mol of the polyamine; and the ratio of a tertiary amine value to a total amine value of the amide …
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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 March 22, 2004 and granted May 8, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 22, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 22, 2026.
- 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
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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.