Patent ID: 8911071

Claim:
An ink jet ink comprising: a pigment; and a polyurethane polymer having units derived from a polyisocyanate, a polyol, and a diol having an acid group, wherein an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less, the unit derived from the polyisocyanate comprises a unit derived from a compound represented by the following general formula (I), and the proportion of the unit derived from the compound represented by the general formula (I) in the unit derived from the polyisocyanate is 90 percent by mole or less where in the general formula (I), R 1 indicates an alkylene group having 6 to 10 carbon atoms, a cycloalkylene group having 6 to 14 carbon atoms, or an arylene group having 6 to 16 carbon atoms, R 2 indicates an alkyl group having 1 to 5 carbon atoms, and R 3 at least has the structure represented by the following general formula (II) where in the general formula (II), n is 4 or more and 70 or less.