Patent ID: 7470015

Claim:
A photopolymerization-curable inkjet-recording ink composition, comprising an ethylenic unsaturated monomer, a colorant, and a photopolymerization initiator containing an organic dye and an organic boron compound, wherein the colorant is an oil-soluble dye having an oxidative potential of higher than 1.1 V (vs. SCE); and wherein the organic boron compound is represented by formula (I): B ←—(R) 4 X + Formula (I) wherein in formula (I), each R is selected from an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, a substituted aralkyl group, an alkaryl group, a substituted alkaryl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an alicyclic group, a substituted alicyclic group, a heterocyclic group, a substituted heterocyclic group, and derivatives of these group; R group may be the same as or different from each other; two or more R group may form a boron-containing heterocyclic ring by combining with each other directly or via a substituent; and X represents an alkali metal, quaternary ammonium, pyridinium, quinolinium, diazonium, morpholinium, tetrazolinium, acrydinium, phosphonium, sulfonium, oxosulfonium, iodonium, S, P, Cu, Ag, Hg, Pd, Fe, Co, Sn, Mo, Cr, Ni, As, or Se.