Energy beam curable composition

Claim 1

An energy beam curable resin composition which comprises as essential constituents a cationically polymerizable substance and an effective amount of an onium salt of a Lewis acid represented the following formula (I) ##STR11## where X is a sulfonio group represented by the following formula (II) ##STR12## where R 1 -R 10 are each a hydrogen atom, halogen atom, nitro group, alkoxy group, C 1 -C 18 aliphatic group, or C 6 -C 18 substituted or unsubstituted phenyl, phenoxy, or thiophenoxy group, with at least one of R 1 -R 10 being (A) a C 1 -C 18 aliphatic group having at least one hydroxyl group or (B) a C 3 -C 19 aliphatic group having a group of --OCH 2 CH 2 O--; Y is a group represented by the above formula (II), hydrogen atom, halogen atom, nitro group, alkoxy group, C 1 -C 18 aliphatic group, C 6 -C 18 substituted or unsubstituted phenyl, phenoxy, or thiophenoxy group, and n=1-3 and m=1-2; and Z is a group represented by the formula MQ l (III) or the formula MQ l-1 OH (IV), where M denotes B, P, As, or Sb; Q denotes a halogen atom; and l is an integer of 4 to 6.