Compositions and process for removing toxic resin acids and derivatives from effluent
CA 2023735 C · Owner: Hodges, Robert Dennis · Inventors: Nickel, Timothy Paul; Hodges, Robert Dennis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to novel compositions and a novel process for removing toxic resin acids and their derivatives from water and waste water effluent. In one specific aspect, the invention pertains to novel compositions and a novel process for removing toxic resin acids from effluent of pulp and paper mills. A composition for treating effluent comprising: (a) a water soluble nonionic polyalkylene ether containing lower alkyl groups in the alkyl chain and having a molecular weight exceeding 50,000; and (b) an ionic water-soluble polymer having a molecular weight exceeding about 10,000.
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 August 21, 1990 and granted March 16, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 21, 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.