Polymers of maleic acid with amines
CA 2173486 A1 · Owner: Calwood Chemical Industries, Inc. · Inventors: Wood, Louis L.; Calton, Gary J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polymers of maleic acid may be prepared by thermally polymerizing malic acid maleic acid or fumaric acid with less than one equivalent of ammonia. The polymers are modified by the incorporation of amines carboxylic acids or combinations thereof. The polymers formed are excellent inhibitors of alkaline earth salt deposition dispersants, tartar control additives, detergent additives and water treatment agents.
Read the whole patent
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 October 3, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 3, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 3, 2016.
- 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.