Victor S. Salvin

Factors Influencing the Dyeing of Acetate Fibers With Disperse Nonionic Dyes

A basic understanding of any textile dyeing process is concerned with those factors , which influence the distribution of dye molecules between an external phase, primarily aqueous, and the fiber phase. An adequate description of the factors affecting the dyeing of acetate fibers with the disperse dye class must include: 1. a detailed description of the dyes in terms of their chemical and physical prop erties and their behavior in the aqueous and fiber phases, 2. the influence of the degree of acetylation of the cellulose upon the dyeing rate and affinity for the disperse dyes, 3. the relationship of specific dye structure tp dyeability and colorfastness on secondary and tricellulose acetate, and 4. a discussion of the mechanism of accelerant or carrier dyeing as applied to cel- . lulose triacetate. White the data presented do not rigorously support either the solution dyeing or the site dyeing hypothesis, sufficient empirical observations are presented which will increase the control and economy of dyeing with the disperse dyes.

Correlation between Colorfastness and Structure of Anthraquinone Blue Disperse Dyes

A correlation is estahlished between the structure of blue amino anthraquinone dyes for cellulose acetate, cellulose triacetate, and the polyester fibers and the colorfastness they exhibit towards the atmospheric agents responsible for gas and ozone fading and towards the action of light. Any structural modification which reduces the electron density on the amino nitrogen attached to the anthraquinone ring, whether it is an amino, an alkylamino, or an arylamino nitrogen, will increase the resistance of the molecule to the electrophilic agents responsible for the chemical changes which occur during fading. Several anthraquinone structures with improved resistance to fading are reported. These contain, as substituents on the arylamino radical, groups which withdraw electrons from the aromatic ring, leaving the amino nitrogen with a low electron density.