Water-thickening copolymers and the use thereof
CA 2046992 C · Owner: Konrad, Gerd · Inventors: Konrad, Gerd; Hartmann, Heinrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Water-thickening copolymers, are obtainable by copolymerization of (A) one or more monomers of the formula I R1HC=CR2R3 I, where, R1 and R2 can be identical or different and each is H or C1-C5-alkyl, and, R3 is, -COOM, -PO3M2 -SO3M, where, R1 and R2 can be identical or different and each is H or C1-C5-alkyl, R4 is H or C1-C5-alkyl R5 is C1-C4-alkylene, R6 and R7 can ba identical or different and each is H or C1-C3-alkyl, and, M is hydrogen or an alkali metal 1/2 alkal-, ine earth metal or ammonium ion and, (B) one or more monomers of the formula IIa or IIb XR1C=CR2.gamma. IIa, where, R1 and R2 can be identical or different and each is H or C1-C5-alkyl, R4 is H or C1-C5-alkyl -2-, X is -COOM …
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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 12, 1991 and granted September 17, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 12, 2013.
- 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.