Patent ID: 7455887

Claim:
An actinic ray curable ink-jet ink composition containing a photopolymerizable compound, a sulfonium salt (compound A) as a photoinitiator, which does not release benzene on actinic ray exposure, a basic compound, and a compound (compound B) as a sensitizing agent selected from the group consisting of (i) a polycyclic aromatic compound having a hydroxyl group, a substituted or unsubstituted aralkyloxy group or a substituted or unsubstituted alkoxy group, (ii) a carbazole derivative, and (iii) a thioxanthone derivative, wherein the sulfonium salt (the compound A) is a sulfonium salt represented by the following formula (3), (4), (5), or (6): wherein R 1 through R 3 independently represent an alkyl group, an alkoxy group, a carbonyl group, a phenylthio group, a halogen atom, a nitro group, or a hydroxy group, provided that at least one of R 1 through R 3 is an alkoxy group; and X − represents an anion; wherein R 4 through R 7 independently represent an alkyl group, an alkoxy group, a carbonyl group, a phenylthio group, a halogen atom, a nitro group, or a hydroxy group, provided that at least one of R 4 through R 7 is an alkoxy group; and X − represents an anion; wherein R 8 through R 11 independently represent an alkyl group, an alkoxy group, a carbonyl group, a phenylthio group, a halogen atom, a nitro group, or a hydroxy group, provided that at least one of R 8 through R 11 is an alkoxy group; and X − represents an anion; wherein R 12 through R 17 independently represent an alkyl group, an alkoxy group, a carbonyl group, a phenylthio group, a halogen atom, a nitro group, or a hydroxy group, provided that at least one of R 12 through R 17 is an alkoxy group; and X − represents an anion.