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Expired Canadian patentCanada

Aqueous dispersions, a process for their preparation and their use as sizing agents

CA 1284004 C · Owner: Johansen, Randi Helene · Inventors: Helmer, Karin Ulla Elisabet; Johansen, Randi Helene; Carlson, Ulf Rune

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Abstract From the Canadian patent

Aqueous dispersions of rosin and synthetic sizing agent wherein the particles in the dispersed phase contain a mixture of rosin and the synthetic sizing agent and wherein the dispersions contain a polyaluminum compound. The dispersions are prepared by homogenization of a homogenous mixture of rosin material and the synthetic sizing agent and the polyaluminum compound can either be present at the production or be added to an aqueous dispersion of mixed particles. The dispersions are used as sizing agents at the production of paper, paper board board and similar, products.

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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

  • Granted May 14, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 14, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJanuary 8, 1988
GrantedMay 14, 1991
Term endedMay 14, 2008
Patent numberCA 1284004 C
Classification (IPC)C08L93/04 +2 more

Timeline

Timeline From CIPO dates

1989199119931995199719992001200320052007Application filedJan 8, 1988Patent grantedMay 14, 1991Term endedMay 14, 2008

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.