Corrosion inhibiting hydraulic cement additives and compositions containing same
CA 2023830 C · Owner: Arfaei, Ahmad · Inventors: Arfaei, Ahmad; Dallaire, Michael P.; Berke, Neal S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An additive combination for hydraulic cement compositions is provided which advantageously provides corrosion inhibition and set acceleration in combination with, a high level of fluidity and retention of fluidity over a desired period of time. The cement additive combination comprises an alkali or alkaline earth metal nitrite and a graft copolymer plasticizer comprising a polyether backbone and side chain polymers formed by polymerization of ethylenically unsaturated monomers. Fluid hydraulic cement compositions are further provided comprising these additive combinations.
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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 August 22, 1990 and granted April 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 22, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 22, 2012.
- 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.