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Expired Canadian patentCanada

Water absorbent acrylic copolymers

CA 1268295 C · Owner: Anderson, Mark · Inventors: Regan, Barbara R.; Alexander, William; Anderson, Mark

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract of the Disclosure Water absorbing, cross-linked acrylate resin copolymers are prepared by aqueous polymerization of (A) acrylic acid neutralized 70 to 100 mole percent for example with ammonia, and/or caustic alkali and/or an amine; with (B) styrene and/or methyl methacrylate in an amount of 1% to 25% based on the weight of acrylic acid or acrylate, and (C) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (C); and (D) a water miscible or a water soluble polyvinyl monomer in an amount of .001 to 0.3 weight percent based on the total weight of (A) (B), (C) and (D).

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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 April 24, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 24, 2007.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 20, 1986
GrantedApril 24, 1990
Term endedApril 24, 2007
Patent numberCA 1268295 C
Classification (IPC)C08F220/06 +2 more

Timeline

Timeline From CIPO dates

1987199019931996199920022005Application filedNov 20, 1986Patent grantedApril 24, 1990Term endedApril 24, 2007

Sources & verification

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