Improvers for adhesion of asphalt to aggregates
CA 2034256 C · Owner: Farnard, Brian A. · Inventors: Sawatzky, Henry; Farnard, Brian A.; Clelland, Floyd I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel bituminous coating compositions, bituminous paving compositions and, asphaltic compositions are provided herein. The essential ingredient in such compositions is an effective amount of a nitrogen-containing anti-stripping , agent, comprising a sewage sludge-derived oil or a fraction thereof, of a , particularly recited composition. Such nitrogen-containing anti-stripping agent improves the adhesion of, asphalt to aggregate in asphalt concrete so that the compositions have many , improved characteristics.
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 January 16, 1991 and granted November 19, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 16, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 16, 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
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.