Process for dyeing hydrophobic textile material with disperse dyes from supercritical CO.sub.2 : reducing the pressure in stages
AssigneeCiba-Geigy Corporation
InventorsWolfgang Saus, Dierk Knittel, Eckhard Schollmeyer, Hans-Jurgen Buschmann
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Abstract
Dyeing polyester textile material with disperse dyes from supercritical CO.sub.2 gives stronger dyeings by carrying out the subsequent pressure reduction in a plurality of steps.
Claims20
A process for dyeing a hydrophobic textile material with a disperse dye which comprises heating the textile material and the disperse dye in supercritical carbon dioxide under a pressure of 73 to 400 bar to a temperature in the range from 80.degree. to 300.degree. C., and subsequently lowering the pressure and the temperature to below the critical pressure and the critical temperature, in which process the pressure reduction is carried out in a number of steps.
Dependencies are inferred from the claim text.