Patent ID: 7897322

Claim:
An ink composition comprising: (A) a polymerization initiator; (B) an ester or amide of a mono-functional acrylic acid having an alkylene oxide repeating unit in a molecule; and (C) a colorant, wherein (B) the ester or amide of a mono-functional acrylic acid having an alkylene oxide repeating unit in a molecule is a compound expressed by the following formula (I): wherein, in formula (I), R 1 denotes a hydrogen atom; X denotes an oxygen atom or NR′ in which R′ denotes a hydrogen atom or an alkyl group; Z 1 denotes an ethylene group and Z 2 denotes an alkylene group having 1 to 6 carbon atoms; n is an integer from 3 to 10; m is an integer from 0 to 80; when m is an integer of 1 or more, Z 1 and Z 2 are not the same; and R 2 denotes a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an aryl group having 6 to 10 carbon atoms; wherein a content of (B) the ester or amide of a mono-functional acrylic acid having an alkylene oxide repeating unit in a molecule is in the range of 1 to 18 mass percent with respect to a total mass of the ink composition.