Multipurpose scale preventer/remover
CA 2066054 C · Owner: Kreh, Robert P. · Inventors: Henry, Wayne L.; Kreh, Robert P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preventing or removing calcium and rust scale deposits from surfaces which are in contact with aqueous systems comprising adding to the aqueous system 3,5-bis(di-N,N-(carboxymethyl)aminomethyl)-4hydroxybenzenesulfonic acid in an amount effective to remove the scale and rust deposits.
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 April 15, 1992 and granted June 25, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 15, 2014.
- 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.