An aqueous inkjet ink composition contains a pigment, an alkali-soluble resin, a polyolefin resin emulsion, a basic compound, an aqueous medium, and a surfactant, wherein the alkali-soluble resin is a copolymer of acrylic acid/lauryl acrylate/styrene; a glass transition temperature of the alkali-soluble resin is 45? C. to 95? C.; an average grain size of the polyolefin resin emulsion is 5 to 300 nm; a solids content of the polyolefin resin emulsion is 0.5 to 5.0 percent by mass in the aqueous inkjet ink composition; and the surfactant contains at least an acetylenediol-based surfactant. The aqueous inkjet ink composition is adapted to offering excellent high-gap discharge stability, antifouling property, adhesion, drying property, abrasion resistance, discharge stability, and preservation stability, even when printed on nonabsorbent media.

An aqueous ink includes water, a solvent group A having a vapor pressure of 0.07 Pa or more at 25? C., a thickener, and a binder polymer. The solvent group A is present in the aqueous ink in a weight percent of 31.0 wt % to 55.0 wt % with respect to a total amount of the aqueous ink. The thickener is present in the aqueous ink in a weight percent of 13.0 wt % or less with respect to the total amount of the aqueous ink. The aqueous ink has a viscosity of 10 mPa.Math.s to 14 mPa.Math.s at 25? C.

An aqueous ink includes water, a solvent group A having a vapor pressure of 0.07 Pa or more at 25? C., a thickener, and a binder polymer. The solvent group A is present in the aqueous ink in a weight percent of 31.0 wt % to 55.0 wt % with respect to a total amount of the aqueous ink. The thickener is present in the aqueous ink in a weight percent of 13.0 wt % or less with respect to the total amount of the aqueous ink. The aqueous ink has a viscosity of 10 mPa.Math.s to 14 mPa.Math.s at 25? C.

An ink jet ink composition includes a pigment, a dispersant, and a biomass resin, the ink jet ink composition being an aqueous ink, in which the pigment is dispersed by the dispersant in water, and the dispersant includes a lignin compound.

Provided is an ink set including black ink and color ink, in which the black ink contains carbon black having a carboxyl group on a surface thereof, a resin particle having a carboxyl group on a surface thereof, betaine, an alkali ion, and water, the alkali ion contains a potassium ion, a sodium ion, and an organic alkali compound, and a content of the potassium ion is the largest among the alkali ions.

Provided is an ink set including black ink and color ink, in which the black ink contains carbon black having a carboxyl group on a surface thereof, a resin particle having a carboxyl group on a surface thereof, betaine, an alkali ion, and water, the alkali ion contains a potassium ion, a sodium ion, and an organic alkali compound, and a content of the potassium ion is the largest among the alkali ions.

A non-Newtonian photo-curable ink composition that comprises a structured network forming agent in an amount ranging from about 0.1 wt % to about 20 wt % by total weight of the ink composition; a salt in an amount ranging from about 0.05 wt % to about 20 wt % by total weight of the ink composition; an organic solvent; a photo-initiator; and a polymerizable material; wherein the ink composition has a first dynamic viscosity ranging from 25 cps to 10,000 cps at a first state and a second dynamic viscosity ranging from 1 cps to 50 cps at a second state. Also described herein is a method for making such non-Newtonian photo-curable ink composition and a method for producing printed images using such non-Newtonian photo-curable ink composition.

An ink set includes: a first ink containing a first anion which is at least one selected from the group consisting of a nitrate ion, an acetate ion, an acrylic acid ion, a formic acid ion, and a methacrylic acid ion; and a second ink containing a second anion which is at least one selected from the group consisting of a sulfate ion, a phosphate ion, and an oxalate ion, wherein the first ink satisfies the following condition (A) and condition (B) and the second ink satisfies the following condition (C) and condition (D):
X150Condition (A):
X1/(X1+X2)>0.6Condition (B): X1: concentration of the first anion in the first ink (ppm) X2: concentration of the second anion in the first ink (ppm)
Y240Condition (C):
Y1/(Y1+Y2)<0.6Condition (D): Y1: concentration of the first anion in the second ink (ppm) Y2: concentration of the second anion in the second ink (ppm).

Provided is an ink jet recording method capable of recording an image excellent in color developability while suppressing ink deposition. The ink jet recording method includes ejecting an aqueous ink from an ejection orifice of a recording head based on image data to record an image on a recording medium and ejecting the heated ink to an ink receiving member from the ejection orifice based on preliminary ejection data. The aqueous ink contains a pigment and a resin dispersant for dispersing the pigment and satisfies at least one of requirement (1): the resin dispersant is a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less and requirement (2): the aqueous ink further contains a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less. The pigment is carbon black whose cumulative 50% particle size in volume-based particle size distribution is 80 nm or less.

Provided is an aqueous ink that enables the recording of images having high optical density and excellent toughness and has excellent reliability. An aqueous ink for ink jet includes a pigment, a resin having an anionic group, a salt and a water-soluble organic solvent. The pigment is a self-dispersible pigment in which an anionic group is bonded to the particle surface of carbon black directly or through another atomic group, the resin has a weight-average molecular weight of 20,000 or less, the water-soluble organic solvent includes glycerol and an additional solvent other than glycerol, and the content (% by mass) of the additional solvent relative to the content (% by mass) of glycerol in terms of mass ratio is 0.6 times or less.