Color of tall oil fractions by treating soap skimmings
CA 2074232 C · Owner: Eastman Chemical Resins, Inc. · Inventors: Macdonald, Charles M.; Suchanec, Richard R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The color and color stability of tall oil fractions are improved and the odor and sulfur content are reduced by treating the heated black liquor soap skimmings prior to acidulation with 1.0 to 1.5 wt. % hydrogen peroxide for at least one minute.
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 July 20, 1992 and granted July 1, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 20, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 20, 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.