Patent ID: 7731763

Claim:
A method of dyeing a substrate comprising: contacting a substrate having reactive groups with supercritical or near supercritical carbon dioxide comprising a reactive dyestuff and at least 0.05 mol. %, calculated on the molar amount of reactive dyestuff, of one or more acids selected from the group consisting of HCl, C 6 H 5 SO 3 H, HNO 3 , CF 3 COOH, H 3 PO 3 , HClO 2 , H 3 PO 4 , CH 2 CICOOH, HF, HNO 2 , HCOOH, and C 6 H 5 COOH, wherein the reactive dyestuff comprises a chromophore derivative having a chromophoric residue and a reactive group.