Abstract: Disclosed are dyes having the formula ##STR1## in which R.sub.1 is C.sub.1 -C.sub.4 alkoxy or chlorine,R.sub.2 is C.sub.1 -C.sub.4 alkyl,R.sub.3 is C.sub.1 -C.sub.4 alkyl,R.sub.4 is C.sub.1 -C.sub.4 alkyl,R.sub.5 is hydroxyethyl or hydroxypropyl, andAn.sup..crclbar. is an anion, in which R.sub.3 and R.sub.4 are not both ethyl at the same time, compositions containing the dyes and methods of using and preparing the dyes. The dyes are especially useful for dyeing polyacrylonitrile.

Abstract: Compounds of the formula ##STR1## where R.sub.1, R.sub.2 and R.sub.3 are each independently of the others hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, halogen or C.sub.1 -C.sub.4 alkanoylamino,R is hydrogen or unsubstituted or C.sub.1 -C.sub.4 alkoxy substituted C.sub.1 -C.sub.12 alkyl or an --(alk)--NA.sup..sym. X.sup..crclbar. radical or,R forms together with an R.sub.1 in the ortho-position relative to the amino group a partially hydrogenated, substituted or unsubstituted 5- to 7-membered heterocyclic ring which may contain additional N, S or O atoms as ring members, (alk) is a substituted or unsubstituted C.sub.1 -C.sub.6 alkylene radical,--NA.sup..sym. is the radical of an amino compound of formula ##STR2## where R.sub.4, R.sub.5 and R.sub.6 are each independently of the others substituted or unsubstituted C.sub.1 -C.sub.6 alkyl, substituted or unsubstituted C.sub.7 -C.sub.12 aralkyl or substituted or unsubstituted aryl, R.sub.8 and R.sub.

Abstract: Process to dye polyacrylonitrile in blue shades with cationic dye compounds: substituted benzothiazolium azo N-alkyl-N-hydroxyalkyl alkyl-aniline salts.