Patent ID: 8408691

Claim:
An ink jet recording ink comprising: (i) a self-dispersion pigment to a surface of which an anionic functional group represented by the following general formula (1) is bonded directly or through another atomic group, (ii) an ammonium salt of an organic carboxylic acid, (iii) water, and (iv) a water-soluble compound having a hydrophilicity-hydrophobicity coefficient of 0.26 or more as defined by the following equation (A), the ink having a surface tension of 34 mN/m or less, wherein M 1 and M 2 are, independently of each other, a hydrogen atom, alkali metal, ammonium or organic ammonium, hydrophilicity-hydrophobicity coefficient =[(Water activity of a 20% aqueous solution)−(Molar fraction of water in the 20% aqueous solution)]/ [1−(Molar fraction of water in the 20% aqueous solution)] (A), and wherein an amount of the ammonium salt of the organic carboxylic acid added into the ink is 0.05% by mass or more and 3% by mass or less.