isopropyl n butyl tert butyl cl br oc n h 2n 1 och 2 ch ch 3 c n h 2n 1 och 2 ch c 2 h 5 c n h 2n 1 och 2 ch oh c n h 2n 1 och 2 co 2 c n h 2n 1 och ch 3 co 2 c n h 2n 1 och c 2 h 5 co 2 c n h 2n 1 and mixtures thereof where n is an integer between 0 and 18 and an u2212 is an anion selected from the group consisting of hexafluoroarsenate asf 6 u2212 hexafluoroantimonate sbf 6 u2212 hexaflourophosphate pf 6 u2212 boron tetrafluoride bf 4 u2212 trifluoromethane sulfonate cf 3 so 3 u2212 and tetrakis pentafluorophenylborate b c 6 f 5 4 u2212 and mixtures thereof or an anion selected from the group consisting of compounds having the following formula wherein m is al ga in or tl r 3 are identical or different and represent a monovalent aromatic hydrocarbon radical having from 6 to 14 carbon atoms with at least one electron withdrawing element or group such as u2014 cf 3 u2014 no 2 or u2014 cn or with at least two halogen atoms x is a halogen atom or hydroxyl group a is 1 2 3 or 4 and b is 0 1 2 or 3 with the proviso that a b 4 there are many commercially available ones e g uvacure u00ae 1600 from ucb chemicals corp smyrna ga having the above formula where r 1 h r 2 o ch 2 7 ch 3 and an sbf 6 u2212 the proportion of epoxy to cationic photoinitiator is 0 25.