Polymaleic acid, its preparation and its use
CA 1268774 C · Owner: Denzinger, Walter · Inventors: Denzinger, Walter; Richter, Felix; Hartmann, Heinrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation of polymaleic acid by polymerizing maleic anhydride in an aromatic hydrocarbon at from 60 to 200°C using from 1 to, 20% by weight, based on maleic anhydride of peroxyesters, derived from saturated or ethylenically unsaturated carboxylic acids, as the polymerization initiators and hydrolyzing the polymer, the polymaleic acid thus obtained and the use of the polymaleic acid as an agent for reducing scale formation and hard water deposits in systems through which water flows.
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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 8, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 8, 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.
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.