INK, INK CARTRIDGE AND INK JET RECORDING METHOD

摘要

An ink containing water, a water-soluble organic solvent and an organic pigment, wherein a primary particle of the organic pigment has a ratio (minor axis b)/(major axis a) of 0.70 or more and a particle diameter of 35 nm or less, the ink contains a water-soluble organic solvent with a dielectric constant of 25.0 or less in an amount of 0.5% by mass or more based on the total mass of the ink, and a dielectric constant epsilonmix of the ink as calculated according to the following equation (1) is 66-72: Equation (1): epsilonmix =∑n epsilonnrn/∑nrn wherein n means a kind of water or the water-soluble organic solvent, epsilonn is a dielectric constant of water or the water-soluble organic solvent represented by n, and rn is a content of water or the water-soluble organic solvent represented by n based on the total mass of the ink.