Method for dyeing polyethylene terephthalate films
CA 2120136 C · Owner: Acquired Technology, Inc. · Inventors: Mercado, Emilio A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of dyeing film of polyethylene terephthalate wherein the film (1) is immersed in a dye bath (15) or solvent or dispersion dyes, dissolved or dispersed or both in a carrier consisting of glycerol triacetate the dye bath (15) being heated so the film (11) is raised to the glass transition temperature of the film (11) and the dye and carrier are absorbed into the film (11). The dye and carrier are removed from the surface of the film (11) by a washing bath (18) and the film (11) is then heated (20) to remove the carrier absorbed in the film (11) without depreciating the dyestuff or the film (11).
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 September 29, 1992 and granted March 16, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 29, 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.