Patent ID: 7682443

Claim:
An organic-pigment aqueous dispersion, comprising a pigment at a concentration of 6 to 30 mass %, and having a haze of 0.3 to 10%, as determined by enclosing the dispersion in a transparent glass cell of optical distance 0.2 mm and analyzing with integrating-sphere photoelectric photometry, wherein the aqueous dispersion contains at least one anionic surfactant that has a solubility of 5 mass % or more in an aprotic polar solvent, the at least one anionic surfactant being represented by formula (I), having a molecular weight of 400 to 2,000 wherein R 1 represents an alkyl group having 5 to 20 carbon atoms; R 2 represents an alkyl, alkenyl, or alkynyl group having 3 to 10 carbon atoms; R 3 represents —SO 3 M or —(CH 2 ) n —COOM, in which M represents a sodium, potassium, or ammonium ion; and n is 1 or 2; and m is an integer of 1 to 20.