WATER-BASED PIGMENT INK

摘要

PROBLEM TO BE SOLVED: To obtain the subject ink excellent in pigment dispersion stability and dryability, thus useful for ink jet printing use, comprising a pigment, (meth) acrylic acid derivative copolymer, aliphatic monohydric alcohol, water-soluble solvent and water. SOLUTION: This water-based pigment ink excellent in pigment dispersibility and ink dryability comprises (A) a pigment such as carbon black, (B) a copolymer from a (meth)acrylic acid derivative of formula I (R1 and R2 are each H or a lower alkyl; (m1 ) is an integer of 0-2; AO is a 2-3C oxyalkylene; (n) is an integer of 1-300; X is H or a lower alkyl) and a monomer of formula II [R3 to R5 are each H, a lower alkyl or a group of the formula (CH2 )m2 COOM2 (M2 is H, an alkali metal, alkaline earth metal, ammonium or amine; (m2 ) is an integer of 0-2); M1 is the same kind as M2 ], (C) an aliphatic monohydric alcohol (e.g. ethyl alcohol), (D) a water-soluble solvent (e.g. diethylene glycol), and water as aqueous medium.