| abstract |
An ink composition includes (A) at least one polymerizable compound selected from the group consisting of a monofunctional radically polymerizable monomer having an aliphatic cyclic structure, an N-vinyllactam, and an aromatic monofunctional radically polymerizable monomer, (B) a radical polymerization initiator, (C) a pigment, and (D) a graft copolymer having a repeating unit represented by the formula below in a graft chain: n nwherein R denotes a hydrogen atom or a methyl group, X denotes a single bond, —O—, —CO—, —COO—, —CONR 1 —, —OCO—, or a phenylene group, R 1 denotes a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, L denotes a single bond or a divalent linking group, Z denotes —NR 2 R 3 , R 2 and R 3 independently denote a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and R 2 and R 3 may be bonded to each other to form a ring. |