Patent ID: 7201791

Claim:
An ink jet light-color ink to be used in combination with an ink jet deep-color ink having a relatively large coloring material content, the ink jet light-color ink comprising at least water, a water-soluble organic solvent and a coloring material, wherein the ink jet deep-color ink satisfies the following conditions (1) and (2); and the ink jet light-color ink satisfies the following conditions (3) to (5); (Conditions) (1) The ink jet deep-color ink comprises at least a compound represented by the following general formula (I) or a salt thereof as a coloring material, and a content (mass %) of the coloring material is 3.0 mass % or more with respect to a total mass of the ink jet deep-color ink; (2) In a dispersion distance distribution, measured by a small-angle X-ray scattering method, of molecular aggregates in the deep-color ink whose coloring material concentration is adjusted to 3.0 mass %, a dispersion distance d 75 value corresponding to 75% of the distribution is 6.50 nm or more and 7.10 nm or less; (3) The coloring material comprises a compound represented by the following general formula (I) or a salt thereof, and a content (mass %) of the coloring material is 0.5 mass % or more and less than 3.0 mass % with respect to a total mass of the ink jet light-color ink; (4) A content (mass %) of 2-pyrrolidone in the water-soluble organic solvent is 50.0% or more with respect to the content (mass %) of the coloring material; (5) In a dispersion distance distribution, measured by a small-angle X-ray scattering method, of molecular aggregates in the light-color ink whose coloring material concentration is adjusted to 0.5 mass %, a dispersion distance d 75 value corresponding to 75% of the distribution is 6.70 nm or more and 10.60 nm or less; wherein M represents an alkali metal or ammonium; R 1 and R 2 each independently represent a hydrogen atom, a sulfonic group, or a carboxyl group (provided that R 1 and R 2 are not simultaneously a hydrogen atom; Y represents a chlorine atom, a hydroxyl group, an amino group, or a monoalkylamino or dialkylamino group; 1 represents 0 to 2, m represents 1 to 3, and n represents 1 to 3 (provided that 1+m+n=3 to 4; and positions at which substituents are present are 4- or 4′-positions.