Water-based inks for ink-jet printing

A water-base ink for ink jet printing, comprising:

• a water dispersion comprising (A) a pigment and (B) water-insoluble polymer particles in a weight ratio [the pigment (A)/the water-insoluble polymer particles (B)] of the pigment (A) to the water-insoluble polymer particles (B) is 20/80 to 90/10,
• wherein the water-insoluble polymer particles are produced by polymerizing ethylenically unsaturated monomers containing 30 to 75% by weight of styrene (a) and 10 to 68% by weight of 2-ethylhexyl (meth)acrylate monomer (c), and acrylic acid (e) in the presence of a reactive sulfonated surfactant,
• wherein the weight ratio [(a)/(c)] of the constitutional unit derived from the aromatic group-containing monomer (a) to the constitutional unit derived from the 2-ethylhexyl (meth)acrylate (c) is from 0.4 to 5
• where the (A) pigment is a self-dispersible carbon black,
• the reactive sulfonated surfactant is at least one sulfosuccinic ester-containing surfactant selected from the group consisting of a compound represented by the following formulae (4) and (5):
• wherein M2 is Na, K or NH4;
• and R8 is an alkyl group having 8 to 18 carbon atoms;
• and
• wherein M2 is Na, K or NH4 and R8 is an alkyl group having 8 to 18 carbon atoms;
• wherein the reactive surfactant is present in an amount of from 0.1 to 3 parts by weight in the water-insoluble polymer particles (B), wherein parts by weight is calculated on the total parts of ethylenically unsaturated monomers;
• and
• wherein the glass transition temperature of the polymer of the (B) water-insoluble polymer particles is −40° C. or higher and 30° C. or lower.