Paper sizing agent composition
CA 2073238 A1 · Owner: Takahashi, Yoshio · Inventors: Hatanaka, Shigeto; Takahashi, Yoshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An alkenylsuccinic anhydride type paper sizing agent composition which causes little contamination of a paper machine and exhibits an excellent sizing effect is provided. The paper sizing agent composition contains addition reaction products obtained from an addition reaction between a straight-chain internal olefin comprising 16 to 20 carbon atoms and maleic anhydride, any unreacted olefin and maleic anhydride having been removed from said addition reaction products; said addition reaction products comprising as a main component alkenylsuccinic anhydride (1 : 1 adduct) represented by formula (I):, (I), wherein both of R and R' are alkyl groups or either one of R and R' is an alkyl group …
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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 July 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 6, 2014.
- 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.