Patent ID: 7662868

Claim:
An ink-jet ink composition comprising (A) a polybutadiene; (B) a radical polymerizable compound having a (meth)acryloyl group; (C) a radical polymerization initiator; and (D) a colorant, wherein the polybutadiene (A) has a repeating unit represented by the following general formula (I): wherein the terminal structure of the polybutadiene (A) is a hydrogen atom, a carboxyl group, a hydroxyethyl group or an isocyanate group, wherein the content of the polybutadiene (A) in the ink composition ranges from 2 to 25% by weight, wherein the polybutadiene (A) has a number average molecular weight ranging from about 500 to about 10,000, and wherein the ink-jet ink composition has a viscosity value as determined at the temperature for discharging the ink composition ranging from 7 to 30 mPa·s.