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 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 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: 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 ink cartridge includes an ink-jet head and plural liquid chambers storing inks different from each other. The minimum value A1 (g/ml) for the ink densities of the inks stored in the plural liquid chambers and the maximum value B1 (g/ml) for the ink densities of inks each obtained by evaporating 10 mass % of each of the inks stored in the plural liquid chambers satisfy the relationship of (B1?A1)/A1?0.100. A stable image can be obtained, in which, even when the ink cartridge is stored for a long time period at the time of physical distribution, or is stored for a long time period in a state of being mounted on a recording apparatus so that the stored inks are brought into a situation in which the inks are apt to evaporate, a change in color balance is small as compared to an initial state.

Abstract: There are provided: a liquid ink for ink jet including: water; a coloring material; 1,5-pentanediol; and a humectant, in which the content of 1,5-pentanediol is 3 mass % or more and 15 mass % or less, and the total of the content of 1,5-pentanediol and the content of the humectant is 10 mass % or more and 40 mass % or less; and an ink jet recording method using the ink.

Abstract: There is provided a cyan ink for ink jet and an ink jet recording method using the same, which can reduce both reciprocating color uneven and beading without impairing fastness property even when a yellow ink or a magenta ink containing a specific coloring material with excellent fastness property is used. In the ink jet recording method using a yellow ink and a cyan ink, or a magenta ink and a cyan ink, the yellow ink and the magenta ink contain a specific coloring material and have a surface tension of 33.0 mN/m or more and 36.0 mN/m or less, and the cyan ink contains a specific phthalocyanine compound, contains 1,5-pentanediol as an organic solvent, and has a surface tension of 32.9 mN/m or more and 35.4 mN/m 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 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 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: If an ink for a particular color (for example, red) having an excellent color developing characteristic is used in addition to inks for three primary colors of subtractive color mixture, the high color reproducibility is to be maintained for a long period. To accomplish this, at least one (for example, a yellow ink) of the inks of two colors between which the hue angle of red, included in the three primary colors, is sandwiched is applied to an area of a printing medium to which a red ink is applied so that the inks overlap each other. Thus, the yellow ink, having a high weatherability, is applied to an area on the printing medium to which only the red ink, having a low weatherability, is otherwise applied. It is therefore possible to improve the weatherability while maintaining the color developing characteristic at a high level.

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 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: 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: Disclosed herein is an image-forming method, including performing image formation on the basis of pixel data by using at least a yellow recording agent, a magenta recording agent, and a third recording agent. A color represented on a recording medium by the third recording agent on a color space of CIE-L*a*b* has lightness higher than lightness of a color reproduction region represented on the recording medium by a combination of the yellow recording agent and the magenta recording agent, and has a hue angle in the color reproduction region. A difference in hue angle on the color space between a color represented by the yellow recording agent and a color represented by the magenta recording agent is in a range of 60 to 113°.

Abstract: There are provided: a liquid ink for ink jet including: water; a coloring material; 1,5-pentanediol; and a humectant, in which the content of 1,5-pentanediol is 3 mass % or more and 15 mass % or less, and the total of the content of 1,5-pentanediol and the content of the humectant is 10 mass % or more and 40 mass % or less; and an ink jet recording method using the ink.

Abstract: There is provided a cyan ink for ink jet and an ink jet recording method using the same, which can reduce both reciprocating color uneven and beading without impairing fastness property even when a yellow ink or a magenta ink containing a specific coloring material with excellent fastness property is used. In the ink jet recording method using a yellow ink and a cyan ink, or a magenta ink and a cyan ink, the yellow ink and the magenta ink contain a specific coloring material and have a surface tension of 33.0 mN/m or more and 36.0 mN/m or less, and the cyan ink contains a specific phthalocyanine compound, contains 1,5-pentanediol as an organic solvent, and has a surface tension of 32.9 mN/m or more and 35.4 mN/m or less.

Abstract: An ink cartridge includes an ink-jet head and plural liquid chambers storing inks different from each other. The minimum value A1 (g/ml) for the ink densities of the inks stored in the plural liquid chambers and the maximum value B1 (g/ml) for the ink densities of inks each obtained by evaporating 10 mass % of each of the inks stored in the plural liquid chambers satisfy the relationship of (B1?A1)/A1?0.100. A stable image can be obtained, in which, even when the ink cartridge is stored for a long time period at the time of physical distribution, or is stored for a long time period in a state of being mounted on a recording apparatus so that the stored inks are brought into a situation in which the inks are apt to evaporate, a change in color balance is small as compared to an initial state.

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.