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: An ink jet aqueous ink including a pigment; a resin dispersant; a fluorinated surfactant; and a water-soluble organic solvent. The pigment comprises quinacridone pigments comprising C.I. Pigment Violet 19, Red 122, 202 or 209; solid solution pigments of two or more thereof; diketopyrrolopyrrole pigments comprising C.I. Pigment Red 254, 255 or 272; or C.I. Pigment Violet 23. The dispersant has an acid value of 150-200 mg KOH/g. The surfactant comprise a perfluoroalkyl ethylene oxide adduct having a C6 or lower perfluoroalkyl group. The solvent contains a water-soluble organic solvent A and B having a dielectric constant of 40.0 or more and 3.0-20.0, respectively. Content p of the pigment is 5.00 mass % or less. Content a of solvent A to content p is 2.0 or more. Content b of solvent B to content a is 0.6 or less. Content b to content f of the surfactant is 10.0 or more.

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: An ink jet aqueous ink including a pigment; a resin dispersant; a fluorinated surfactant; and a water-soluble organic solvent. The pigment comprises quinacridone pigments comprising C.I. Pigment Violet 19, Red 122, 202 or 209; solid solution pigments of two or more thereof; diketopyrrolopyrrole pigments comprising C.I. Pigment Red 254, 255 or 272; or C.I. Pigment Violet 23. The dispersant has an acid value of 150-200 mg KOH/g. The surfactant comprise a perfluoroalkyl ethylene oxide adduct having a C6 or lower perfluoroalkyl group. The solvent contains a water-soluble organic solvent A and B having a dielectric constant of 40.0 or more and 3.0-20.0, respectively. Content p of the pigment is 5.00 mass % or less. Content a of solvent A to content p is 2.0 or more. Content b of solvent B to content a is 0.6 or less. Content b to content f of the surfactant is 10.0 or more.

Abstract: An ink containing water, a water-soluble organic solvent and an organic pigment, wherein a primary particle of the organic pigment has a ratio (minor axis b)/(major axis a) of 0.70 or more and a particle diameter of 35 nm or less, the ink contains a water-soluble organic solvent with a dielectric constant of 25.0 or less in an amount of 0.5% by mass or more based on the total mass of the ink, and a dielectric constant ?mix of the ink as calculated according to the following equation (1) is 66-72: ?mix=?n?nrn/?nrn??Equation (1): wherein n means a kind of water or the water-soluble organic solvent, ?n is a dielectric constant of water or the water-soluble organic solvent represented by n, and rn is a content of water or the water-soluble organic solvent represented by n based on the total mass of the ink.

Abstract: The invention provides provide an ink jet ink exhibiting such an excellent ejection property that when an ink containing a polymer capable of improving the scratch resistance of a recorded article is used, the deviation of the ink-droplet impact point on a recording medium is prevented. The ink jet ink contains a polymer and a surfactant, wherein the acid value of the polymer is from 100 mg KOH/g or more to 220 mg KOH/g or less, the weight-average molecular weight of the polymer is from 3,000 or more to 10,000 or less, and the surfactant has a structure represented by the following formula (1) wherein n is a numerical value of from 3 or more to 27 or less, and m is a numerical value of from 16 or more to 31 or less.

Abstract: Provided is an aqueous ink capable of recording an image achieving a high level of both of color developability and lightfastness. The aqueous ink includes a first pigment and a second pigment. The first pigment is C.I. Pigment Yellow 213, and the second pigment is at least one selected from the group consisting of C.I. Pigment Yellows 93, 128, 138, 151, 155, 180, and 215. The content A (% by mass) of the first pigment and the content B (% by mass) of the second pigment based on a total mass of the ink satisfy a relationship of 0.1?A/(A+B)?0.9. The ink further includes a water-soluble organic solvent having an SP value (unit: (cal/cm3)1/2) determined by Fedors' method of 11.0 or more and 16.0 or less.

Abstract: Provided is a pigment particle suitable for an ink capable of recording an image that is excellent in color developability and lightfastness, and has a yellow hue. The pigment particle is a pigment particle having a structure represented by the following formula (1), in which a maximum absorption wavelength of an absorption spectrum in a wavelength region of 200 nm or more and 800 nm or less is present in a range of 340 nm or more and 360 nm or less.

Abstract: An ink containing water, a water-soluble organic solvent and an organic pigment, wherein a primary particle of the organic pigment has a ratio (minor axis b)/(major axis a) of 0.70 or more and a particle diameter of 35 nm or less, the ink contains a water-soluble organic solvent with a dielectric constant of 25.0 or less in an amount of 0.5% by mass or more based on the total mass of the ink, and a dielectric constant ?mix of the ink as calculated according to the following equation (1) is 66-72: ?mix=?n?nrn/?nrn??Equation (1): wherein n means a kind of water or the water-soluble organic solvent, ?n is a dielectric constant of water or the water-soluble organic solvent represented by n, and rn is a content of water or the water-soluble organic solvent represented by n based on the total mass of the ink.

Abstract: Provided is an aqueous ink capable of recording an image achieving a high level of both of color developability and lightfastness. The aqueous ink includes a first pigment and a second pigment. The first pigment is C.I. Pigment Yellow 213, and the second pigment is at least one selected from the group consisting of C.I. Pigment Yellows 93, 128, 138, 151, 155, 180, and 215. The content A (% by mass) of the first pigment and the content B (% by mass) of the second pigment based on a total mass of the ink satisfy a relationship of 0.1?A/(A+B)?0.9. The ink further includes a water-soluble organic solvent having an SP value (unit: (cal/cm3)1/2) determined by Fedors' method of 11.0 or more and 16.0 or less.

Abstract: Provided is a pigment particle suitable for an ink capable of recording an image that is excellent in color developability and lightfastness, and has a yellow hue. The pigment particle is a pigment particle having a structure represented by the following formula (1), in which a maximum absorption wavelength of an absorption spectrum in a wavelength region of 200 nm or more and 800 nm or less is present in a range of 340 nm or more and 360 nm or less.

Abstract: An ink contains at least a pigment, wherein the pigment is a solid solution of C.I. Pigment Red 202 and C.I. Pigment Violet 19, and a primary particle diameter D (nm) of the pigment and a 50%-cumulative diameter D50 (nm) in particle diameter distribution of the pigment satisfy a relation of D×0.95?(=<)D50?(=<)130, and a 90%-cumulative diameter D90 (nm) in particle diameter distribution of the pigment and the 50%-cumulative diameter D50 (nm) satisfy a relation of 1.5?(=<)D90/D50?(=<)2.2.

Abstract: An ink contains at least a pigment, wherein the pigment is C.I. Pigment Red 282, and a primary particle diameter D (nm) of the pigment and a 50%-cumulative diameter D50 (nm) in particle diameter distribution of the pigment satisfy a relation of D×0.95?D50?150, and a 90%-cumulative diameter D90 (nm) in particle diameter distribution of the pigment and the 50%-cumulative diameter D50 (nm) satisfy a relation of 1.5?D90/D50?2.5.

Abstract: An ink contains at least a pigment, wherein the pigment is a solid solution of C.I. Pigment Red 202 and C.I. Pigment Violet 19, and a primary particle diameter D (nm) of the pigment and a 50%-cumulative diameter D50 (nm) in particle diameter distribution of the pigment satisfy a relation of D×0.95?(=<)D50?(=<)130, and a 90%-cumulative diameter D90 (nm) in particle diameter distribution of the pigment and the 50%-cumulative diameter D50 (nm) satisfy a relation of 1.5?(=<)D90/D50?(=<)2.2.

Abstract: An ink contains at least a pigment, wherein the pigment is C.I. Pigment Red 282, and a primary particle diameter D (nm) of the pigment and a 50%-cumulative diameter D50 (nm) in particle diameter distribution of the pigment satisfy a relation of D×0.95?D50?150, and a 90%-cumulative diameter D90 (nm) in particle diameter distribution of the pigment and the 50%-cumulative diameter D50 (nm) satisfy a relation of 1.5?D90/D50?2.5.

Abstract: An aqueous ink to be used in an ink jet recording method that an ink is ejected from a recording head by the action of thermal energy, wherein the ink contains a pigment, a polymer and a water-soluble organic solvent, the hydrophilicity ?m of the pigment falls within a range of from 21.5 or more to 23.5 or less, and the content (mass %) of the water-soluble organic solvent is from 5.0 mass % or more to 17.5 mass % or less with respect to the whole mass of the aqueous ink.

Abstract: A network device connecting a plurality of Ethernet links, includes: an Ethernet maintenance and administration section for periodically checking whether a link fault occurs on each Ethernet link; a link manager for updating link status information for each Ethernet link according to a check result of the Ethernet link; and a link switching processor for switching from a fault-detected Ethernet link to another Ethernet link according to link status information of the Ethernet links.

Abstract: The invention provides provide an ink jet ink exhibiting such an excellent ejection property that when an ink containing a polymer capable of improving the scratch resistance of a recorded article is used, the deviation of the ink-droplet impact point on a recording medium is prevented. The ink jet ink contains a polymer and a surfactant, wherein the acid value of the polymer is from 100 mg KOH/g or more to 220 mg KOH/g or less, the weight-average molecular weight of the polymer is from 3,000 or more to 10,000 or less, and the surfactant has a structure represented by the following formula (1) wherein n is a numerical value of from 3 or more to 27 or less, and m is a numerical value of from 16 or more to 31 or less.

Abstract: An aqueous ink to be used in an ink jet recording method that an ink is ejected from a recording head by the action of thermal energy, wherein the ink contains a pigment, a polymer and a water-soluble organic solvent, the hydrophilicity ?m of the pigment falls within a range of from 21.5 or more to 23.5 or less, and the content (mass %) of the water-soluble organic solvent is from 5.0 mass % or more to 17.5 mass % or less with respect to the whole mass of the aqueous ink.

Abstract: An ink contains at least a pigment, wherein the pigment is a solid solution of C.I. Pigment Red 202 and C.I. Pigment Violet 19, and a primary particle diameter D (nm) of the pigment and a 50%-cumulative diameter D50 (nm) in particle diameter distribution of the pigment satisfy a relation of D×0.95?(=<)D50?(=<)130, and a 90%-cumulative diameter D90 (nm) in particle diameter distribution of the pigment and the 50%-cumulative diameter D50 (nm) satisfy a relation of 1.5?(=<)D90/D50?(=<)2.2.