Patent ID: 8882255

Claim:
An ink jet ink comprising a coloring material, a polymer particle, a crosslinking agent and an aqueous medium, wherein: the polymer particle has a unit derived from a compound represented by a following general formula (I) and a glass transition temperature of 25° C. or less, the crosslinking agent has a functional group capable of forming a crosslinked structure with a ketone group derived from the compound represented by the general formula (1) by a dehydration reaction, and a mass ratio of a content (% by mass) of the coloring material based on the total mass of the ink to a content (% by mass) of the polymer particle based on the total mass of the ink is 0.2 times or more and 2.5 times or less, wherein R 1 is H or CH 3 , X is O or NH, R 2 is an alkylene group having 1 to 10 carbon atoms or an aromatic ring structure having 1 to 10 carbon atoms, and R 3 is an alkyl group having 1 to 10 carbon atoms or an aromatic ring structure having 1 to 10 carbon atoms.