Patent ID: 7015258

Claim:
An ink composition for ink jet recording, comprising an azo dye, a humectant, water, and an amino-group-containing water-soluble compound that undergoes condensation polymerization in the absence of the water, wherein a substituent selected from a straight-chain or branched alkyl group whose carbon number is two or more, an alkoxyl group, a phenyl group or a derivative group thereof, a phenoxyl group, or a six-membered or larger cycloalkyl group is introduced to a carbon atom at an α-position of the amino group in the amino-group-containing water-soluble compound that undergoes condensation polymerization in the absence of water to enclose the azo dye and to improve water-resistivity of the ink composition, wherein said substituent serves as steric hindrance to said amino group attacking an azo group of the azo dye and prevents discoloration and/or fading of the ink composition.