Hydantoin-enhanced halogen efficacy in pulp and paper applications
CA 2202631 C · Owner: Sweeny, Philip Gerdon · Inventors: Sweeny, Philip Gerdon
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Free halogen sources (e.g. sodium hypochlorite and chlorine) added as slimicides in high organic component process streams such as pulp and paper processing are rendered more efficacious by the addition of selected Nhydrogen compounds (namely, 5,5-dimethylhydantoin 5-ethyl-5-methylhydantoin, cyanuric acid succinimide, urea, 4,4-dimethyl-2-oxazolidinone and glycouril) , to the process stream. The latter compounds may be added to the process stream before or after the slimicide is added or combined with the slimicide and added directly thereto. The direct use of halogenated hydantoins has also been found to provide improved efficacy relative to free halogen sources. In addition, …
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 13, 1995 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 13, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 13, 2017.
- 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.