Acid donor process for dyeing polyamide fibers and textiles
CA 2323489 A1 · Owner: Wicker, Calvin M. Jr. · Inventors: Login, Robert B.; Bella, Otto; Wicker, Calvin M. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for dyeing materials containing natural or synthetic polyamides is disclosed. The process includes immersing the materials to be dyed in a dye bath containing an acid dye. The pH of the dye bath is initially at a level that substantially inhibits the dye from being absorbed by the polymer. In accordance with the present invention, however an acid producing composition , is added to the bath which gradually reduces the pH of the bath and allows for uniform diffusion of the dye into the polymer. The acid producing composition of the present invention is a maleate ester which, in one embodiment, is the , reaction product of maleic acid or maleic anhydride and a glycol.
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 March 11, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 11, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2021.
- 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.