Abstract: A photosensitive recording material comprising a solvent-soluble, thermosetting epoxy oligomer capable of cationic polymerization, an aliphatic monomer having at least one ethylenically unsaturated bond, the monomer being liquid at normal temperature and pressure, having a boiling point of 100.degree. C. or above at normal pressure and being capable of radical polymerization, a photoinitiator selected from the group consisting of i) a first photoinitiator capable of simultaneously generating a radical species that activates radical polymerization and a Br.o slashed.nsted acid or Lewis acid that activates cationic polymerization, upon exposure to actinic radiation, and ii) a second photoinitiator comprised of a radical polymerization photoinitiator capable of generating a radical species that activates radical polymerization upon exposure to actinic radiation and a cationic polymerization photoinitiator capable of generating a Br.o slashed.

Abstract: A photopolymerization initiator composition almost free from deactivation and capable of giving a photopolymerizable composition which is almost free from a decrease in the photopolymerization rate in a medium having a high viscosity and shows a high curing rate, containing(A) a sulfonium organoboron complex or oxosulfonium organoboron complex of the formula (1), ##STR1## (B) a sensitizer having electron donating capability and electron acceptability in an excited state.

Abstract: A sulfonium complex or oxosulfonium complex of the formula (1), ##STR1## wherein R.sup.1 is a benzyl group, a substituted benzyl group, a phenacyl group, a substituted phenacyl group, an aryloxy group, a substituted aryloxy group, an alkenyl group or a substituted alkenyl group, each of R.sup.2 and R.sup.3 is independently any one of groups defined as R.sup.1, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, a substituted aralkyl group, an alkynyl group, a substituted alkynyl group, an alicyclic group, a substituted alicyclic group, an alkoxyl group, a substituted alkoxyl group, an alkylthio group, a substituted alkylthio group, an amino group or a substituted amino group, or R.sup.2 and R.sup.3 may bond together forming a ring structure, R.sup.4 is an oxygen atom or lone pair, and each of R.sup.5, R.sup.6, R.sup.7 and R.sup.