Air controlling superplasticizers
CA 2224782 C · Owner: Lambert, James F. · Inventors: Lambert, James F.; Arfaei, Ahmad
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polymeric additives for hydraulic cement compositions which impart to the wet cement composition greater plasticity, lower slumploss over time and water , reduction capability without the problems of air entrainment associated with prior polymeric additives of this type. The superplasticizers have a carbon backbone formed by polymerization of ethylenically-unsaturated carboxylic acids, the backbone comprising carboxylic acid grafting sites to which are covalently attached a) air detraining functional side chains which are first , polyoxyalkylene groups of the general formula: R4-(OA2)x-Qwherein Q = O or , NH; A2 = C1-C10alkylene; x = 1 to 200; and R4 = C1-C10alkyl and b) second , …
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 June 19, 1996 and granted November 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 19, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2018.
- 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.