Abstract: The present invention provides a colorant dispersion for a recording ink containing at least a dispersant, a colorant, and water, wherein the dispersant is a polycarboxylic acid dispersant containing units represented by formulae (1) to (3): where R1, R2, and R4 are selected from a hydrogen atom and CH3; R3 is selected from a hydrogen atom and a C1-C3 alkyl group; R5 represents a C1-C3 alkyl group; AO and BO represent a C2-C3 oxyalkylene group; M is selected from alkali metal, alkali earth metal, ammonium, and organic amine; m represents an integer of 1 to 30; and n represents an integer of 5 to 50.

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 an inkjet recording ink containing at least a pigment dispersion liquid A containing at least a first carbon black, a dispersant, and water, and a self-dispersible pigment dispersion liquid B which contains a second carbon black having a surface functional group, wherein a mass ratio (Ac:Bc) of the amount of the first carbon black (Ac) in the pigment dispersion liquid A to the amount of the second carbon black (Bc) having a surface functional group in the self-dispersible pigment dispersion liquid B is 98:2 to 50:50.

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 set containing at least a black pigment ink and a color pigment ink which has a color selected from one or more colors, wherein the black pigment ink contains a first anionic self-emulsifying ether polyurethane resin having an acid value of 65 mgKOH/g to 85 mgKOH/g, and the at least one color pigment ink of every color contains a second anionic self-emulsifying ether polyurethane resin having an acid value 10 mgKOH/g to 40 mgKOH/g lower than those of the first anionic self-emulsifying ether polyurethane resin contained in the black pigment ink.

Abstract: The present invention provides an inkjet pigment dispersion liquid including a carbon black, a dispersant, and water, wherein the total number of coarse particles having a particle diameter of 0.5 ?m or greater contained in the inkjet pigment dispersion liquid is 1,000,000/5 ?L or less, and provides an inkjet ink using the inkjet pigment dispersion liquid.

Abstract: To provide an inkjet ink containing C4-6 diol; and trimethylglycine.

Abstract: An inkjet recording ink which contains: a carbon black; a dispersant; resin emulsion; and water, in which the resin emulsion contains a resin which is at least one of a urethane resin and a styrene-acryl resin, and the ink satisfies the following relationship: 20?B?A?50, where A(nm) represents a particle diameter D90 of particles contained in dispersion containing the carbon black, the dispersant, and water, which is before added with the resin emulsion, and B(nm) represents a particle diameter D90 of particles contained in the ink.

Abstract: The present invention provides a colorant dispersion for a recording ink containing at least a dispersant, a colorant, and water, wherein the dispersant is a polycarboxylic acid dispersant containing units represented by formulae (1) to (3): where R1, R2, and R4 are selected from a hydrogen atom and CH3; R3 is selected from a hydrogen atom and a C1-C3 alkyl group; R5 represents a C1-C3 alkyl group; AO and BO represent a C2-C3 oxyalkylene group; M is selected from alkali metal, alkali earth metal, ammonium, and organic amine; m represents an integer of 1 to 30; and n represents an integer of 5 to 50.

Abstract: An inkjet recording ink including a carbon black, a dispersant, a polyurethane resin particle, and water, where the carbon black is a channel black, a gas black, or a mixture of channel black and a gas black, and the polyurethane resin particle is an anionic self-emulsifying ether-based polyurethane resin particle, wherein the anionic self-emulsifying ether-based polyurethane resin particle has an acid value of 40 to 120 and a mass average molecular weight of 500 to 50,000, and an average primary particle diameter of 20 nm or less.

Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.

Abstract: The present invention provides an inkjet recording ink containing at least a pigment dispersion liquid A containing at least a first carbon black, a dispersant, and water, and a self-dispersible pigment dispersion liquid B which contains a second carbon black having a surface functional group, wherein a mass ratio (Ac:Bc) of the amount of the first carbon black (Ac) in the pigment dispersion liquid A to the amount of the second carbon black (Bc) having a surface functional group in the self-dispersible pigment dispersion liquid B is 98:2 to 50:50.

Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.

Abstract: The present invention provides a pigment dispersion that contains a carbon black, a dispersing agent and water, wherein the carbon black is any one of a channel black and a gas black, the dispersing agent is a sodium naphthalenesulfonate formalin condensate, and the total content of a dimer, a trimer and a tetramer of naphthalenesulfonate in the sodium naphthalenesulfonate formalin condensate is 20% by weight to 80% by weight. The present invention also provides an inkjet ink using the pigment dispersion.

Abstract: The present invention provides a pigment dispersion that contains a carbon black, a dispersing agent and water, wherein the carbon black is any one of a channel black and a gas black, the dispersing agent is a sodium naphthalenesulfonate formalin condensate, and the total content of a dimer, a trimer and a tetramer of naphthalenesulfonate in the sodium naphthalenesulfonate formalin condensate is 20% by weight to 80% by weight. The present invention also provides an inkjet ink using the pigment dispersion.

Abstract: An ink-jet ink including a pigment a dispersant, a water, a particulate resin (A) dyed with a fluorescent dye and having an average particle diameter of from 50 to 200 nm, and an emulsion of a self-emulsifiable polyurethane; and a method for preparing the ink-jet ink, an ink cartridge containing the ink-jet ink, an image forming method using the ink-jet ink, and an image formed with the ink-jet ink.

Abstract: A method for preparing a pigment dispersion including subjecting a mixture including at least a pigment, a dispersant and water to a first dispersion treatment using a media mill to prepare a first dispersion; and then subjecting the first dispersion to a second dispersion treatment using a media-less mill to prepare the pigment dispersion, wherein the pigment in the pigment dispersion has an average particle diameter (D50) of from 20 to 130 nm for pigments except carbon black or from 70 to 180 for carbon black, and the standard deviation of the particle diameter of the pigment is less than the average particle diameter (D50) for pigments except carbon black or one half of the average particle diameter (D50) for carbon black. A pigment dispersion prepared by the method. An inkjet ink including the pigment dispersion and one member selected from water, water soluble organic solvents, and surfactants.

Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.

Abstract: An inkjet ink including water; a particulate pigment; a dispersant; and an emulsion, wherein the particulate pigment has an average particle diameter (D50) not greater than 100 nm, and the standard deviation of particle diameter distribution of the particulate pigment is less than one half of the average particle diameter (D50). An inkjet cartridge containing the inkjet ink. An inkjet recording apparatus including the inkjet cartridge and a carriage configured to carry the ink cartridge. An inkjet recording method including discharging the inkjet ink from a nozzle of a recording head to form an ink image on a recording paper. An image formed on a recording material in accordance with the inkjet recording method.

Abstract: A pigment dispersion including a pigment; a dispersant; and a dispersion medium including water, wherein the pigment is dispersed in the dispersion medium, wherein the average particle diameter D50 of the pigment is not greater than 50 nm and the standard deviation of the pigment particle diameter distribution thereof is less than the average particle diameter D50. An inkjet ink including the pigment dispersion and at least one of water, a water-soluble organic solvent and a surfactant. A method and apparatus for forming an image using the inkjet ink. An image produced by the image forming method and apparatus.