Abstract: An inkjet recording ink set, which contains at least: a black pigment ink; and a color pigment ink, wherein the black pigment ink contains a black pigment treated with an anionic surfactant, and a black pigment coated with a resinous polymer, and water, and the black pigment ink is a pigment dispersion liquid where the black pigment treated with the anionic surfactant and the black pigment coated with the resinous polymer are dispersed in the water, and wherein the color pigment ink contains a color pigment, a nonionic surfactant, and water, and the color pigment ink is a pigment dispersion liquid where the color pigment is dispersed in the water with assistance of the nonionic surfactant.

Abstract: An inkjet ink including water, a pigment, a polymer, and a hydrazine compound. The polymer does not include an anionic unit and includes a first unit having a carbonyl group capable of reacting with a hydrazino group, and a second unit having at least one of an amino group, a dimethylamino group, and a diethylamino group. The content of the first unit is from 40% to 90% by weight based on the weight of the polymer, and the inkjet ink has a pH of not less than 9.

Abstract: Ink for ink jet recording containing a coloring agent, water, an aqueous organic solvent, and a polyacrylic acid ester-based polymer represented by the following chemical structure 1: where R represents a hydrogen atom and a methyl group, X— represents F—, Cl—, and Br—, M+ represents Na+, K+, NH4+, and Li+, and symbols l, m, n, and p independently represent integers of from 10 to 3,000.

Abstract: An inkjet recording ink including: water; a first pigment dispersion; a second pigment dispersion; and a penetrating agent, wherein the first pigment dispersion includes oxidized carbon black CB-1 dispersed therein with a pH of the first pigment dispersion adjusted to 6 to 8 with an alkali metal hydroxide, where the oxidized carbon black CB-1 is oxidized with ozone and has a volatile content of 10% to 20% and a BET specific surface area of 90 m2/g to 150 m2/g, and the second pigment dispersion includes carbon black CB-2 dispersed therein with a naphthalene sulfonic acid-formalin condensate, where the carbon black CB-2 has an average particle diameter (D50) of 50 nm to 180 nm as measured by a dynamic light scattering method and a standard deviation of particle diameters of the carbon black CB-2 is equal to or lower than ½ of the average particle diameter.

Abstract: An inkjet recording ink including a pigment dispersion liquid containing at least a first carbon black and a dispersant, a second carbon black, a penetrant, a wetting agent and water, wherein the first carbon black has an average particle diameter D50 of 70 nm to 180 nm as measured by a dynamic light scattering method and has a particle diameter standard deviation equal to or smaller than ½ of the average particle diameter, wherein the dispersant is a condensate of naphthalene sulfonic acid and formalin, wherein the second carbon black is carbon black coated with a resin, and wherein the penetrant is a 2-ethyl-1,3-hexandiol.

Abstract: The present invention provides a recording ink set containing a black ink, a cyan ink, a magenta ink, and a yellow ink, each of which contains water, a water-insoluble color material, a water-soluble organic solvent, and a surfactant, wherein the black ink and at least one of the inks other than the black ink respectively contain a different water-soluble organic solvent; and the surface tension of the water-soluble organic solvent(s) used only for the inks other than the black ink is higher than that of the water-soluble organic solvent used only for the black ink; and the present invention also provides a recording method using the recording ink set.

Abstract: An ink for inkjet recording containing water, water-soluble organic solvent, water-dispersible resin, fluorochemical surfactant or derivative thereof, and coloring agent containing pigment, where the ink has a surface tension of 20-35 mN/m and viscosity of ?5 mPa·s at 25° C., total amount of the water-dispersible resin and the coloring agent in the ink is 5-40% by mass, and mass ratio A/B of the water-dispersible resin A to the coloring agent B is 0.5-4, where the ink is applied to a recording medium containing a support containing cellulose pulp, and one or more barrier layers disposed on a face of the support, and where the barrier layer contains ?30% by mass of inorganic pigment having refractive index of ?1.5, excluding aluminum hydrate, and ?10% by mass of inorganic pigment having a refractive index of <1.5.

Abstract: An inkjet recording ink including water; a dispersant containing a block type copolymer having structural unit of a diene monomer and an aromatic vinyl monomer, wherein the block type copolymer has a sulfonic acid group or salt thereof; a first carbon black; and a second carbon black having 2.0 ?mol/m2 to 5.0 ?mol/m2 of a carboxyl group on a surface thereof.

Abstract: An inkjet recording ink including: water; a first pigment dispersion; a second pigment dispersion; and a penetrating agent, wherein the first pigment dispersion includes oxidized carbon black CB-1 dispersed therein with a pH of the first pigment dispersion adjusted to 6 to 8 with an alkali metal hydroxide, where the oxidized carbon black CB-1 is oxidized with ozone and has a volatile content of 10% to 20% and a BET specific surface area of 90 m2/g to 150 m2/g, and the second pigment dispersion includes carbon black CB-2 dispersed therein with a naphthalene sulfonic acid-formalin condensate, where the carbon black CB-2 has an average particle diameter (D50) of 50 nm to 180 nm as measured by a dynamic light scattering method and a standard deviation of particle diameters of the carbon black CB-2 is equal to or lower than ½ of the average particle diameter.

Abstract: An ink-jet recording ink including water, a water-soluble organic solvent, a pigment as a colorant (B), and at least one fluorochemical surfactant selected from compounds represented by Structural Formula (1) below, Structural Formula (1) where R1 denotes any one of a hydrogen atom, an alkyl group and a perfluoroalkyl group, R2 denotes any one of a hydrogen atom, an alkyl group and a fluorine-containing group, Rf denotes a fluorine-containing group, and m and n each denote an integer of 1 or greater.

Abstract: An ink jet recording medium having an ink receiving layer containing a binder which containing an acrylonitrile butadiene type copolymer, the butadiene concentration of the copolymer is 50 weight % or more, and an inorganic pigment on one or two sides of a base paper mainly composed of wood pulp, wherein the concentration ratio of the acrylonitrile butadiene type copolymer to 100 parts by weight of the inorganic pigment is from one part by weight to eight parts by weight, while 60 weight % or more of the inorganic pigment is kaolin with particles of 0.4 ?m or more and below 4.2 ?m which account for 64% or more as the cumulative value of the volumetric basis when measured using a laser diffraction method, and the surface roughness of the ink receiving layer is from 0.6 ?m to 1.4 ?m when a hard backing is used at a clamp pressure of 1,000 kPa according to JIS P8151.

Abstract: The present invention provides an ink-media set, record printed by use of the ink-media set, an inkjet printing method, and an inkjet printing apparatus which includes ink that has at least water, dye, and humectant and surface tension thereof is 20 to 35 mN/m at 25° C., a support, and a recording medium having the support and at least one surface thereof has a coating layer wherein transfer rate of the ink to the recording medium measured by a dynamic scanning absorptometer in 100 ms of contact time is 4 to 15 ml/m2 and transfer rate of the ink to the recording medium measured by a dynamic scanning absorptometer in 400 ms of contact time is 7 to 20 ml/m2.

Abstract: An ink for inkjet recording containing water, water-soluble organic solvent, water-dispersible resin, fluorochemical surfactant or derivative thereof, and coloring agent containing pigment, where the ink has a surface tension of 20-35 mN/m and viscosity of ?5 mPa·s at 25° C., total amount of the water-dispersible resin and the coloring agent in the ink is 5-40% by mass, and mass ratio A/B of the water-dispersible resin A to the coloring agent B is 0.5-4, where the ink is applied to a recording medium containing a support containing cellulose pulp, and one or more barrier layers disposed on a face of the support, and where the barrier layer contains ?30% by mass of inorganic pigment having refractive index of ?1.5, excluding aluminum hydrate, and ?10% by mass of inorganic pigment having a refractive index of <1.5.

Abstract: A recording ink containing at least a solid component which contains a colorant and a resin and is a solid at 25° C., a liquid component which has a higher boiling point than that of water and is a liquid at 25° C. and water, wherein the total content of the liquid component in the recording ink is 20% by mass or less, the total content of the solid component in the recording ink is 20% by mass or more, and the total content of a resin component in the solid component is 40% by mass to 95% by mass relative to a total amount of the solid component is provided.

Abstract: An inkjet ink including water, a pigment, a polymer, and a hydrazine compound. The polymer does not include an anionic unit and includes a first unit having a carbonyl group capable of reacting with a hydrazino group, and a second unit having at least one of an amino group, a dimethylamino group, and a diethylamino group. The content of the first unit is from 40% to 90% by weight based on the weight of the polymer, and the inkjet ink has a pH of not less than 9.

Abstract: An inkjet recording ink set, which contains at least: a black pigment ink; and a color pigment ink, wherein the black pigment ink contains a black pigment treated with an anionic surfactant, and a black pigment coated with a resinous polymer, and water, and the black pigment ink is a pigment dispersion liquid where the black pigment treated with the anionic surfactant and the black pigment coated with the resinous polymer are dispersed in the water, and wherein the color pigment ink contains a color pigment, a nonionic surfactant, and water, and the color pigment ink is a pigment dispersion liquid where the color pigment is dispersed in the water with assistance of the nonionic surfactant.

Abstract: To provide an ink for inkjet recording containing water, water-soluble organic solvent, water-dispersible resin, fluorochemical surfactant or derivative thereof, and coloring agent containing pigment, wherein the ink has a surface tension of 20-35 mN/m and viscosity of 5 mPa·s or more at 25° C., total amount of the water-dispersible resin and the coloring agent in the ink is 5-40% by mass, and mass ratio A/B of the water-dispersible resin A to the coloring agent B is 0.5-4, wherein the ink is applied for a recording medium for inkjet recording containing a support containing cellulose pulp, and one or more barrier layers disposed on at least one face of the support, and wherein the barrier layer contains 30% by mass or more of inorganic pigment having refractive index of 1.5 or more, excluding aluminum hydrate, and 10% by mass or less of an inorganic pigment having a refractive index of less than 1.5.

Abstract: A recording ink containing: a solid component containing a colorant, and a resin, and being solid in ink at 25° C., a liquid component having a boiling point higher than that of water and being liquid in ink at 25° C., and water, wherein the total amount of the solid component contained in the recording ink is equal to 8.5% by mass or higher and less than 15% by mass, a ratio (A/B) of the total amount of a water-soluble organic solvent (A), which is contained in the liquid component and has a high-boiling point of 280° C. or higher (A), to the total amount of the solid component (B) contained in the recording ink is 1.1 to 2.5, and a ratio (C/B) of the total amount of the liquid component (C) in the recording ink to the total amount of the solid component (B) in the recording ink is 1.85 to 3.10.

Abstract: An inkjet recording ink including a pigment dispersion liquid containing at least a first carbon black and a dispersant, a second carbon black, a penetrant, a wetting agent and water, wherein the first carbon black has an average particle diameter D50 of 70 nm to 180 nm as measured by a dynamic light scattering method and has a particle diameter standard deviation equal to or smaller than ½ of the average particle diameter, wherein the dispersant is a condensate of naphthalene sulfonic acid and formalin, wherein the second carbon black is carbon black coated with a resin, and wherein the penetrant is a 2-ethyl-1,3-hexandiol.

Abstract: An inkjet recording apparatus, includes: a black ink ejecting portion configured to eject a black ink containing a self-dispersion pigment; color ink ejecting portions configured to eject, respectively, a cyan ink, a magenta ink and a yellow ink which contain a polymer emulsion containing a polymer fine particle containing a coloring material which is insoluble in water or slightly soluble in water; and a recording-controlling unit configured to control recording. When the recording medium is optically transparent and is provided, on a transparent base material thereof, with an ink accepting layer, the recording-controlling unit controls recording on the recording medium such that the color ink ejecting portion is used for recording a monochrome image and a color image which has a plurality of colors, leaving the black ink ejecting portion substantially free from being used.