Abstract: An aqueous ink for use in an ink jet recording method in which ink is thermally ejected from a recording head to record an image on a recording medium. The aqueous ink includes zirconium oxide; a pigment; a resin dispersant for the pigment; and a first and a second urethane resin. The content (ppm) of the zirconium oxide in terms of zirconium is 0.5-20.0 ppm based on the total mass of the ink. The pigment is at least one of phthalocyanine, quinacridone, diketopyrrolopyrrole, dioxazine, perinone, perylene and anthraquinone pigments. Each of the first and second urethane resins has a unit derived from a polyether polyol. The ratio of the weight-average molecular weight Mw1 of the first urethane resin to the weight-average molecular weight Mw2 of the second urethane resin is 0.20-0.80 times. The second urethane resin has a weight-average molecular weight Mw2 of 20,000-70,000.

Abstract: The present invention relates to an ink set enabling the recording of images that have excellent gloss clarity and abrasion resistance even when a plurality of inks are used in combination, and an ink jet recording method using the ink set.

Abstract: An aqueous ink for ink jet including a pigment; a water-soluble acrylic resin for dispersing the pigment; a water-soluble urethane resin; and a nonionic fluorinated surfactant. The water-soluble acrylic resin includes a copolymer having two or more units derived from two or more kinds of monomers, and of the two or more units, a unit derived from a monomer that gives a homopolymer having a glass transition temperature Tg of 0° C. or more is contained in a proportion of 95.0% by mass or more. The water-soluble urethane resin has a weight-average molecular weight of 6,000 or more.

Abstract: The invention provides an ink containing a first coloring material and a second coloring material, wherein the first coloring material is a compound represented by a general formula (1), and the second coloring material is a compound represented by a general formula (2).

Abstract: Provided is an ink capable of recording an image that is excellent in ozone resistance, hardly causes blurring or color change even in a high-humidity environment, and is excellent in humidity resistance. The ink includes a coloring material and a lithium ion. The coloring material includes a compound represented by the following general formula (I) and a content of the lithium ion in the ink is 3.5 times or more in terms of molar ratio with respect to a content of the compound represented by the general formula (I).

Abstract: Provided is an ink capable of recording an image that is excellent in ozone resistance, hardly causes blurring or color change even in a high-humidity environment, and is excellent in humidity resistance. The ink includes a coloring material and a lithium ion. The coloring material includes a compound represented by the following general formula (I) and a content of the lithium ion in the ink is 3.5 times or more in terms of molar ratio with respect to a content of the compound represented by the general formula (I).

Abstract: An ink set having a cyan ink, a magenta ink and a yellow ink. A combination of a cyan, magenta and yellow dye respectively contained in the cyan, magenta and yellow ink is selected so as to satisfy the condition that optical density retentions of images formed by a cyan ink for evaluation containing the cyan dye, a magenta ink for evaluation containing the magenta dye and a yellow ink for evaluation containing the yellow dye, as determined before and after an ozone resistance test with an integral ozone concentration of 800 ppm·hr and before and after a xenon light resistance test with an integral irradiance of 43,800 klx·hr, are 70% or more for each of the inks for evaluation and are such that a maximum value of differences of the optical density retentions among the images formed by the respective inks for evaluation is 15 or less.

Abstract: The invention provides an ink containing a first coloring material and a second coloring material, wherein the first coloring material is a compound represented by a general formula (1), and the second coloring material is a compound represented by a general formula (2).

Abstract: The present invention is a colorant compound represented by the following general formula (1): wherein at least one of R2, R4, R7 and R9 is an acylamino group represented by the following general formula (2): wherein R11 denotes one of an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkenyl group and a heterocyclic group; and ‘*’ denotes a bonding site with an aromatic ring of the general formula (1).

Abstract: An ink jet ink is provided which can retain good stability and shows superior intermittent ejection stability not only under a low-temperature, low-humidity environment but also a high-temperature, low-humidity environment even when the evaporation of water in the ink progresses. The ink jet ink includes a coloring material and water-soluble organic solvents, wherein the content of the coloring material is less than 7.0 mass %, the water-soluble organic solvents include glycerin and a branched alkanediol having hydroxyl groups at both terminals of its main chain, the content C of glycerin is 6.0 to 12.0 mass %, the content A of the branched alkanediol is 4.0 to 11.0 mass %, and the content A of the branched alkanediol and the total content B of the water-soluble organic solvents satisfy the relationship of 0.30?A/B?0.50.

Abstract: An ink jet ink is provided which contains at least a coloring material and a water-soluble organic solvent, where the water-soluble organic solvent contains a branched alkanediol having hydroxyl groups at both terminals of its main chain and at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2): R1-[A]-R2??General formula (1)

Abstract: An ink set having a cyan ink, a magenta ink and a yellow ink. A combination of a cyan, magenta and yellow dye respectively contained in the cyan, magenta and yellow ink is selected so as to satisfy the condition that optical density retentions of images formed by a cyan ink for evaluation containing the cyan dye, a magenta ink for evaluation containing the magenta dye and a yellow ink for evaluation containing the yellow dye, as determined before and after an ozone resistance test with an integral ozone concentration of 800 ppm·hr and before and after a xenon light resistance test with an integral irradiance of 43,800 klx·hr, are 70% or more for each of the inks for evaluation and are such that a maximum value of differences of the optical density retentions among the images formed by the respective inks for evaluation is 15 or less.

Abstract: The present invention is a colorant compound represented by the following general formula (1): wherein at least one of R2, R4, R7 and R9 is an acylamino group represented by the following general formula (2): wherein R11 denotes one of an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkenyl group and a heterocyclic group; and ‘*’ denotes a bonding site with an aromatic ring of the general formula (1).

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: The present invention provides an ink jet ink having a magenta color which gives an image excellent in magenta color tone and also excellent in image fastness (lightfastness and gas resistance). The ink jet ink includes a first coloring material that is an anthrapyridone compound having a structure represented by general formula (I) and/or general formula (II) and a second coloring material that is an azo compound having a structure represented by general formula (III), wherein the mass ratio of the content of the first coloring material to the content of the second coloring material is from 2.5 or more to 10.0 or less.

Abstract: An ink jet ink is provided which can retain good stability and shows superior intermittent ejection stability not only under a low-temperature, low-humidity environment but also a high-temperature, low-humidity environment even when the evaporation of water in the ink progresses. The ink jet ink includes a coloring material and water-soluble organic solvents, wherein the content of the coloring material is less than 7.0 mass %, the water-soluble organic solvents include glycerin and a branched alkanediol having hydroxyl groups at both terminals of its main chain, the content C of glycerin is 6.0 to 12.0 mass %, the content A of the branched alkanediol is 4.0 to 11.0 mass %, and the content A of the branched alkanediol and the total content B of the water-soluble organic solvents satisfy the relationship of 0.30?A/B?0.50.

Abstract: An ink jet ink is provided which contains at least a coloring material and a water-soluble organic solvent, where the water-soluble organic solvent contains a branched alkanediol having hydroxyl groups at both terminals of its main chain and at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2): R1-[A]-R2??General formula (1)

Abstract: The present invention provides an ink jet ink having a magenta color which gives an image excellent in magenta color tone and also excellent in image fastness (lightfastness and gas resistance). The ink jet ink includes a first coloring material that is an anthrapyridone compound having a structure represented by general formula (I) and/or general formula (II) and a second coloring material that is an azo compound having a structure represented by general formula (III), wherein the mass ratio of the content of the first coloring material to the content of the second coloring material is from 2.5 or more to 10.0 or less.

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.