Polyester copolymer fiber having enhanced strength dyeability properties
CA 2049402 A1 · Owner: Hoechst Celanese Corporation · Inventors: Roderiguez, Joseph A.; Meiss, Theodore D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is a method of producing a polyester filament which has a superior combination of tensile dyeability and, shrinkage properties. The method comprises forming a polyester copolymer from a mixture consisting essentially of terephthalic acid (TA) or dimethyl terephthalate (DMT) ethylene glycol, adipic, acid, and pentaerythritol wherein the adipic acid is added in an amount of between 1.3 and 3.2 weight percent of the terephthalic acid and pentaerythritol is added in the amount from 175 to 700 ppm by weight of terephthalic acid; forming the filament from the copolymer, drawing the copolymer filament and heat-setting the, drawn filament. The invention also comprises the enhanced …
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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 16, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 16, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 16, 2013.
- 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.