Abstract: A pigment ink is provided which is used in an ink jet recording apparatus in which ejection orifices for a pigment ink and ejection orifices for at least one type of reactive ink that destabilizes a dispersed state of pigment in the pigment ink are capped with the identical cap provided with a unit for removing an ink in the cap, achieving compatibility between bleeding resistance and reliability. Where a mixed thickening ratio upon mixing the pigment ink and the reactive ink in equal volumes is represented by Y (%) and an ejection orifice-to-ejection orifice distance between the ejection orifice for the pigment ink and the ejection orifice for the reactive ink is represented by X (mm) (provided that X>0), Y and X satisfy a specific relationship.

Abstract: An object of the present invention is to provide coated fine particles with a uniform particle size, having stable crystals on the surface, and to provide colored fine particles which exhibit good color development. A recorded image formed by a dispersion and an ink, using the coated fine particles, is provided with good color development and fastness. The present invention provides coated fine particles comprising fine particles as cores, the fine particles having a crystal layer on the surface, respectively.

Abstract: An ink jet ink which can form images whose bleeding resistance is high and whose bronzing phenomenon is suppressed, is provided. The ink is an ink jet ink for use together with a pigment ink. The ink jet ink is characterized in that: the ink jet ink contains a coloring material, a polyvalent metal and a water-soluble organic solvent(s); the coloring material is at least a compound represented by the general formula (I); a content (mol/g) of the polyvalent metal is 2.0×10?6 mol/g or more and 4.0×10?4 mol/g or less; a total content (mass %) of the water-soluble organic solvent(s) is 25.0 mass % or more with respect to the total mass of the ink; and in a dispersion distance distribution, measured by a small angle X-ray scattering method, of molecular aggregates in the ink jet ink whose coloring material concentration is adjusted to 0.5 mass %, a dispersion distance d75 value corresponding to 75% of a distribution is 12.60 nm or less.

Abstract: Ink jet ink which sufficiently suppresses curling phenomenon of printed matters and satisfies ejection stability, the ink comprising at least water, a colorant, a water-soluble organic compound 1 and a water-soluble organic compound 2, wherein the content X(%) of the water-soluble organic compound 1 is 10 mass % or more based on the total amount of the ink jet ink and the content X(%) of the water-soluble organic compound 1 and the content Y(%) of the water-soluble organic compound 2 based on the total amount of the ink jet ink satisfy the relation of the following formula (I) and formula (II): 0<Y/X?0.9, ??(I) X+Y?15 mass %, ??(II) and wherein the water-soluble organic compound 1 is a water-retentive, water-soluble organic compound having a difference between the water retention ability in an environment of a temperature of 23° C. and a humidity of 45% and the water retention ability in an environment of a temperature of 30° C.

Abstract: An image forming method using a black ink containing a pigment, a black ink containing a dye, and a reactive color ink capable of unstabilizing the dispersion state of the pigment in the black ink, wherein the method includes one of the steps of, on at least part of a region to which the black ink is to be applied, applying the reactive color ink, the black ink, and the black ink in that order so as to overlap, thereby applying these inks to a recording medium; and applying the black ink, the black ink, and the reactive color ink in that order so as to overlap, thereby applying these inks to a recording medium.

Abstract: An ink jet recording ink comprising at least a copper phthalocyanine dye represented by the following general formula (1) and a compound represented by the following general formula (2):

Abstract: An ink comprising yellow colorants and a colorant having a phthalocyanine skeleton, in which the yellow colorants are at least a colorant represented by the following general formula I and C.I.

Abstract: An object of the present invention is to provide coated fine particles with a uniform particle size, having stable crystals on the surface, and to provide colored fine particles which exhibit good color development. A recorded image formed by a dispersion and an ink, using the coated fine particles, is provided with good color development and fastness. The present invention provides coated fine particles comprising fine particles as cores, the fine particles having a crystal layer on the surface, respectively.

Abstract: There are provided a novel pigment dispersion that can be suitably used as a coloring material for inks, especially inks for ink-jet recording, comprising a colored pigment in primary particles dispersed stably in a liquid medium, and a process for producing the pigment dispersion. A pigment dispersion comprising a colored pigment that is substantially of a primary particle maintaining type and is dispersed in a liquid medium, a process for producing the pigment dispersion, and an ink and recorded image using the pigment dispersion.

Abstract: There is provided a method for producing pigment crystals with sufficiently high purity and sufficiently controlled crystal type, particle size, and aggregation property and dispersibility to obtain a pigment crystal that can be suitably used in both a solid phase and a liquid phase. The method for producing pigment crystals (S3) from a pigment precursor (S0) using retro Diels-Alder reaction, the method comprising producing the pigment crystals (S3) from the pigment precursor (S0) through a first displacement structure (S1) and a second displacement structure (S2), which differ from the pigment precursor (S0) and the pigment crystals (S3) and also differ from at least from each other.

Abstract: An ink comprising yellow colorants and a colorant having a phthalocyanine skeleton, in which the yellow colorants are at least a colorant represented by the following general formula I and C.I. Direct Yellow 132.

Abstract: An ink jet recording ink comprising at least a copper phthalocyanine dye represented by the following general formula (1) and a compound represented by the following general formula (2):

Abstract: Ink jet ink which sufficiently suppresses curling phenomenon of printed matters and satisfies ejection stability, the ink comprising at least water, a colorant, a water-soluble organic compound 1 and a water-soluble organic compound 2, wherein the content X(%) of the water-soluble organic compound 1 is 10 mass % or more based on the total amount of the ink jet ink and the content X(%) of the water-soluble organic compound 1 and the content Y(%) of the water-soluble organic compound 2 based on the total amount of the ink jet ink satisfy the relation of the following formula (I) and formula (II): 0<Y/X?0.9,??(I) X+Y?15 mass %,??(II) and wherein the water-soluble organic compound 1 is a water-retentive, water-soluble organic compound having a difference between the water retention ability in an environment of a temperature of 23° C. and a humidity of 45% and the water retention ability in an environment of a temperature of 30° C.

Abstract: The present invention provides an anti-curl agent containing an amide compound of specific structure and molecular weight, an ink jet ink containing the amide compound, a method for ink jet recording to form images by ejecting the ink, and a method for reducing curl of recording media using the ink. The anti-curl agent of the present invention can reduce shape changes of a printed paper with a lapse of time, i.e., the curl phenomenon, tending to occur in particular with a plain paper printed over the entire surface, without deteriorating image quality.

Abstract: The present invention provides an anti-curl agent containing an amide compound of specific structure and molecular weight, an ink jet ink containing the amide compound, a method for ink jet recording to form images by ejecting the ink, and a method for reducing curl of recording media using the ink. The anti-curl agent of the present invention can reduce shape changes of a printed paper with a lapse of time, i.e., the curl phenomenon, tending to occur in particular with a plain paper printed over the entire surface, without deteriorating image quality.