Patent ID: 7988278

Claim:
An inkjet ink, comprising: a pigment; water; a surfactant; and from 40 to 75 weight % of a polar aprotic solvent having a molecular weight of 40 to 130, wherein the surfactant is, in combination, (a) a silicone-based surfactant S 1 expressed by Formula (1): where R 1 indicates a polyalkylene oxide chain containing at least one ethylene oxide group or propylene oxide group, and x indicates a numeral of no less than 1 and (b) a silicone-based surfactant S 2 expressed by the Formula (2): where R 2 indicates a polyalkylene oxide chain containing at least one ethylene oxide group or propylene oxide group, and y indicates a numeral of no less than 1, and wherein the two silicone-based surfactants S 1 and S 2 have a blending ratio (weight ratio) S 1 /S 2 that ranges from 6/4 to 4/6.