Abstract: An ink jet ink containing a pigment and a polyurethane polymer, wherein the polyurethane polymer has units derived from a polyol having no acid group and having the carbon number of 13 or more and 250 or less, a diol having an acid group and having the carbon number of 1 or more and 7 or less, a polyol having a siloxane structure, and a polyisocyanate, and an acid value of the polyurethane polymer is 40.0 mgKOH/g or more and 80.0 mgKOH/g or less.

Abstract: An ink jet ink includes a pigment and a polyurethane polymer having units derived from a polyisocyanate, a polyol, and a diol having an acid group, and in the ink jet ink described above, an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less, the unit derived from the polyisocyanate includes a unit derived from a compound represented by the following general formula (I), and the proportion of the unit derived from the compound represented by the general formula (I) in the unit derived from the polyisocyanate is 90 percent by mole or less.

Abstract: An ink jet ink contains a self-dispersing pigment and a polyurethane polymer. The polyurethane polymer has units derived from a polyisocyanate, a polyol having no acid group, and a diol having an acid group. The polyurethane polymer has a cross-linked structure and an acid value of the polyurethane polymer is 60 mgKOH/g or more and 100 mgKOH/g or less.

Abstract: An ink jet ink including a pigment and an ABC triblock polymer, wherein the above-described ABC triblock polymer is formed from an A block having an aryl group, a B block having a unit represented by the following general formula (1), and a C block having a unit represented by the following general formula (2).

Abstract: An ink jet ink contains a pigment and a polyurethane polymer. The polyurethane polymer contains units derived from a polyisocyanate, a polyol, a compound having a carboxy group, and a compound having a sulfo group, and an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less.

Abstract: An ink jet ink contains a self-dispersing pigment and a polyurethane polymer. The polyurethane polymer has units derived from a polyisocyanate, a polyol having no acid group, and a diol having an acid group. The polyurethane polymer has a cross-linked structure and an acid value of the polyurethane polymer is 60 mgKOH/g or more and 100 mgKOH/g or less.

Abstract: An ink jet ink includes a pigment and a polyurethane polymer having units derived from a polyisocyanate, a polyol, and a diol having an acid group, and in the ink jet ink described above, an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less, the unit derived from the polyisocyanate includes a unit derived from a compound represented by the following general formula (I), and the proportion of the unit derived from the compound represented by the general formula (I) in the unit derived from the polyisocyanate is 90 percent by mole or less.

Abstract: An aqueous ink to be used together with a pigment ink containing a pigment and a polymer, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: An ink jet ink including a pigment and an ABC triblock polymer, wherein the above-described ABC triblock polymer is formed from an A block having an aryl group, a B block having a unit represented by the following general formula (1), and a C block having a unit represented by the following general formula (2).

Abstract: An ink jet ink containing a pigment and a polyurethane polymer, wherein the polyurethane polymer has units derived from a polyol having no acid group and having the carbon number of 13 or more and 250 or less, a diol having an acid group and having the carbon number of 1 or more and 7 or less, a polyol having a siloxane structure, and a polyisocyanate, and an acid value of the polyurethane polymer is 40.0 mgKOH/g or more and 80.0 mgKOH/g or less.

Abstract: An aqueous ink used together with a black ink containing a self-dispersion pigment, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the self-dispersion pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: An ink jet ink contains a pigment and a polyurethane polymer. The polyurethane polymer contains units derived from a polyisocyanate, a polyol, a compound having a carboxy group, and a compound having a sulfo group, and an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less.

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 inkjet ink contains at least one coloring material selected from the group of C. I. Direct Violet 107, C. I. Acid Red 14, C. I. Acid Red 52, C. I. Acid Red 87, C. I. Acid Red 289 and C. I. Reactive Red 180, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium. The ratio of the content in the inkjet ink of the compound expressed by general formula (I) to the total content of coloring materials in the inkjet ink is in the range of 15.0% by mass or more to 40.0% by mass or less.

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 inkjet ink contains at least one coloring material selected from the group of C. I. Direct Violet 107, C. I. Acid Red 14, C. I. Acid Red 52, C. I. Acid Red 87, C. I. Acid Red 289 and C. I. Reactive Red 180, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium. The ratio of the content in the inkjet ink of the compound expressed by general formula (I) to the total content of coloring materials in the inkjet ink is in the range of 15.0% by mass or more to 40.0% by mass or less.

Abstract: An aqueous ink used together with a black ink containing a self-dispersion pigment, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the self-dispersion pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: An aqueous ink to be used together with a pigment ink containing a pigment and a polymer, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

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: 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.