Aromatic-aliphatic ketones useful as photoinitiators

A compound of the formula ##STR13## wherein A is --CO-- or --CO--CO--;

• X is --OR.sup.5 ;
• Z is --S--, or --O--;
• m is O or an integer of 1 to 3;
• n is O or an integer of 1 to 3;
• R.sup.1 is alkyl of 1-12 C atoms, cycloalkyl of 5-6 C atoms, aryl of 6-14 C atoms, aralkyl of 7-9 C atoms, --OH, --OAlk, --OAr, --SAlk, --SCH.sub.2 CH.sub.2 OH, --SAr, --SO.sub.2 Alk, --SO.sub.2 phenyl, --SO.sub.2 NH.sub.2, --SO.sub.2 NHAlk, --SO.sub.2 N(Alk).sub.2, --COOAlk, --NH.sub.2, --NHAlk, --N(Alk).sub.2, --NHCOphenyl, --CN or halogen;
• R.sup.2 can be any of the groups defined for R.sup.1 or another --CO--CR.sup.3 R.sup.4 X group;
• R.sup.3 is H, alkyl of 1-8 C atoms, or alkyl of 1-8 C atoms substituted by --OH, --OAlk, acyloxy of 2-8 C atoms, --NR.sup.8 R.sup.9, --COOAlk or --CN, or is alkenyl of 3-5 C atoms;
• R.sup.4 can be any of the groups defined for R.sup.3 or --CH.sub.2 CH.sub.2 R.sup.13 ;
• R.sup.5 is H, alkyl of 1-12 C atoms or alkyl of 1-8 C atoms substituted by --Cl, --Br, --OH, --OAlk, --SAlk, acyloxy of 2-8 C atoms, --COOAlk, --CONHAlk, --CON(Alk).sub.2 or --CN, or is alkenyl of 3-5 C atoms, or cyclohexyl;
• R.sup.8 is alkyl of 1-12 C atoms, or alkyl of 2-4 C atoms substituted by --OH, --OAlk or --CN, or is alkenyl of 3-5 C atoms, or cyclohexyl;
• R.sup.9 is alkyl of 1-12 C atoms, or alkyl of 2-4 C atoms substituted by --OH, --OAlk or --CN, or is alkenyl of 3-5 C atoms, or cyclohexyl, or, together with R.sup.8, is alkylene of 4-5 C atoms or C.sub.4-5 -alkylene interrupted by --O-- or --NR.sup.14 --, or, together with R.sup.4, is alkylene of 1-9 C atoms, oxa- or aza-alkylene of 2-3 C atoms;
• R.sup.13 is --CONH.sub.2, --CONHAlk, or --CON(Alk).sub.2 ;
• R.sup.14 is alkyl of 1-4 C atoms;
• Alk is alkyl of 1-4 C atoms;
• and
• Ar is C.sub.6-14 aryl or aryl substituted by alkyl groups and having a total of 6-14 C atoms;
• wherein aryl stands for hydrocarbon aryl groups and acyl groups are derived from hydrocarbon carboxylic acids.