Decolorization of polyethylene polyamines using ruthenium
CA 2117579 A1 · Owner: Su, Wei-Yang · Inventors: Su, Wei-Yang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for the reduction of the color of polyamines by reacting at elevated temperature e.g. 120-170°C.and pressure, e.g. 500 to 6000 psig. the colored polyamines e.g. triethylenetetramine and tetraethylenepentamine in the presence of a, ruthenium on alumina hydrogenation catalyst. The catalyst for the polyamine decolorization process preferably has at least 0.5 wt.% Ru. In the process of the present invention, the polyamines can either be distilled into a narrow product composition and then hydrogenated or a crude polyamine, product can be hydrogenated and then distilled to produce the desired product composition.
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 24, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 24, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 24, 2016.
- 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.