Compounds of the formula I, II or III ##STR1## in which Ar is a sulfur-containing aromatic radical, R.sup.1 and R.sup.2 are a monovalent hydrocarbon radical which is substituted or unsubstituted or R.sup.1 and R.sup.2 together form alkylene, oxaalkylene or azaalkylene, R.sup.3 is a direct bond or a divalent hydrocarbon radical, X is a monovalent amino group and X' is a divalent amino or diamino group, are excellent photoinitiators for the photocuring of colored, in particular pigmented, compositions containing an olefinically unsaturated, photopolymerizable binder.
式I、II或III的化合物##STR1##中,Ar是含
硫芳基,R.sup.1和R.sup.2是单价的碳氢基团,可以被取代或未取代,或者R.sup.1和R.sup.2一起形成烷基,氧杂烷基或氮杂烷基,R.sup.3是直接键或双价的碳氢基团,X是单价
氨基团,X'是双价
氨基或二
氨基团。这些化合物是优秀的光
引发剂,适用于光固化着色的,特别是含有烯丙基不饱和光聚合物的
颜料组合物。