Water-based pigment dispersion

A water-based pigment dispersion comprising 100 parts by weight of a pigment, 0.1 to 30 parts by weight of a pigment dispersing agent of the formula (1) and 5 to 500 parts by weight, as a solid content, of a water-based resin which is obtained by copolymerizing 5 to 20% by weight of an .alpha., .beta.-ethylenically unsaturated carboxylic acid (a), 5 to 50% by weight of an .alpha., .beta.-ethylenically unsaturated, nitrogen-containing monomer (b) and 30 to 90% by weight of an .alpha., .beta.-ethylenically unsaturated monomer (c) other than the .alpha., .beta.-ethylenically unsaturated carboxylic acid (a) and the .alpha., .beta.-ethylenically unsaturated, nitrogen-containing monomer (b),

• P--[X--Y--Z--N(R.sup.1)R.sup.2 ].sub.n ( 1)
• wherein:
• P is an organic dyestuff residue or a heterocyclic ring residue,
• X is a divalent binding group consisting of 2 to 15 atoms selected from S, C, N, O and H atoms,
• Y is a direct bond, --N(R)-- in which R is H, an alkyl group having 1 to 18 carbon atoms or Q--N(R.sup.3)R.sup.4 in which Q is an alkylene group having 1 to 6 carbon atoms and each of R.sup.3 and R.sup.4 is independently an optionally substituted alkyl group having 1 to 18 carbon atoms or R.sup.3 and R.sup.4 are together forming an optionally substituted heterocyclic ring which may contain N, O or S, or --O--,
• Z is an alkylene group having 1 to 6 carbon atoms, and each of R.sup.1 and R.sup.2 is independently an optionally substituted alkyl group having 1 to 18 carbon atoms or R.sup.1 and R.sup.2 are together forming an optionally substituted heterocyclic ring which may contain N, O or S, and
• n is an integer of 1 to 3.