Photocurable ink composition and method for forming image

A photocurable ink composition comprising:

• an amine A which is an amine compound having an α-hydrogen atom and a hindered amine structure;
• an amine B which is a tertiary amine compound that has an α-hydrogen atom, that has no hindered amine structure, and that has no radical-polymerizable group;
• at least one of a monofunctional radical-polymerizable monomer or a bifunctional radical-polymerizable monomer;
• and
• a sensitizer (D) which is at least one of a compound represented by formula (D1) below or a compound represented by formula (D2) below,
• wherein a total content of the monofunctional radical-polymerizable monomer and the bifunctional radical-polymerizable monomer is 50% by mass or more based on a total amount of the photocurable ink composition:
• wherein, in formula (D1), R1 represents a halogen atom, an alkyl group, an aryl group, a hydroxy group, a cyano group, a nitro group, an amino group, an alkylsulfanyl group, an alkylamino group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, an acyl group, a carboxy group, or a sulfo group;
• R2 represents an alkyl group or an aryl group;
• n1 represents an integer of 0 to 5;
• when n1 is an integer of 1 to 5, R2 and at least one of le may be bound together to form a ring;
• and
• when n1 is an integer of 2 to 5, the plurality of Rl may be the same or different, and
• wherein, in formula (D2), R3 to R8 each independently represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group.