Patent ID: 8672466

Claim:
An ink composition comprising a polymerization initiator, water, and a modified polyallylamine or modified polyvinylamine having an ethylenically unsaturated double bond in a side chain thereof, wherein the ethylenically unsaturated double bond comprises a structure represented by the following Formula (I-A): wherein, in Formula (I-A), B 2 represents an alkylene group having from 1 to 8 carbon atoms or a carbonyl group; R 21 represents a single bond or an arylene group having from 6 to 10 carbon atoms; R 22 represents a hydrogen atom or a methyl group; and * represents a bonding site; wherein the modified polyallylamine or modified polyvinylamine having an ethylenically unsaturated double bond in a side chain thereof comprises a compound having a structure represented by the following Formula (I): wherein, in Formula (I), A 1 represents Formula (I-A); X 1 represents a hydrogen atom or the following Formula (I-X); and n 1 represents 0 or 1: wherein, in Formula (I-X), Y 31 represents an alkylene group having from 1 to 8 carbon atoms or an arylene group having from 6 to 10 carbon atoms; Z 31 represents a hydrogen atom or —COOM 31 ; M 31 represents an alkaline metal atom; and * represents a bonding site; and wherein the compound comprising the structure represented by Formula (I) further comprises a structure represented by the following Formula (I′): wherein, in Formula (I′), X 2 represents the following Formula (I′-X); and n 2 represents 0 or 1: wherein, in Formula (I′-X), Y 32 represents an alkylene group having from 1 to 8 carbon atoms or an arylene group having from 6 to 10 carbon atoms; Z 32 represents a hydrogen atom or —COOM 32 ; M 32 represents an alkaline metal atom; and * represents a bonding site.