A New Reactive System for Continuous Dyeing and Printing of Cellulose and Blends

Abstract

A new, unique system for the continuous dyeing of cellulose is reported. It requires dyes containing phosphorus acid subgroups which are believed to condense with the active hydrogen on the cellulose to join the chromophore through the phosphorus atom. This takes place in the presence of cyanamide-type compounds and heat. The dyes are applied at pH 5 to 6, and so are suitable for co-application with disperse dyes. This process lowers the cost of continuous dyeing of cotton in polyester blends compared to disperse-vat dye systems, while retaining the wet colorfastness typical of reactive systems. A full range of shades can be obtained, and the difference between dyeings on mercerized and un mercized cloth is slight. Both the dyeing and printing processes have been shown in full-scale production to be readily suitable for use in existing plants without the need for new equipment, and are applicable to typical commercial fabrics.