Control of dye migration in thermosol dyeing processes

Claim 1

A Thermosol process for dyeing a cellulosic textile with a vat-disperse dye mixture which comprises: (a) passing a cellulosic textile through a pigment pad containing (1) an aqueous dispersion of a dye mixture of an unreduced vat dye and a disperse dye and (2) an antimigrating agent comprising an aqueous solution of about 0.25 to 0.55 ounces per gallon of a non-ionic water-soluble polymer selected from the group consisting of melamine formaldehyde and urea formaldehyde polymers and about 0.15 to 0.45 ounces per gallon of a salt selected from the group consisting of sodium chloride, sodium sulfate, sodium formate, potassium chloride, potassium sulfate, potassium formate, and potassium acetate, which is added to the aqueous dispersion of the dye mixture; (b) drying the textile with the dye mixture thereon; (c) heating the dried textile to fix the disperse dye in the dye mixture; (d) passing the textile with the unreduced vat dye and fixed disperse dye thereon through a chemical pad solution maintained at a temperature above the reduction temperature of the vat dye of the dye mixture; said chemical pad solution comprising sodium dithionite, sodium hydroxide and an aldehyde bisulfite or an aldehyde sulfoxylate addition product; and (e) subjecting the textile obtained in step (d) to steam in a developing chamber.