Abstract: The present invention relates to [1] a water-based ink containing an azomethine metal complex pigment (A), an aromatic group-containing polymer (B), an organic solvent (D) and water, in which a mass ratio of the azomethine metal complex pigment (A) to the aromatic group-containing polymer (B) [(A)/(B)] is not less than 1.4 and not more than 4, and the aromatic group-containing polymer (B) is a crosslinked polymer obtained by crosslinking an aromatic group-containing polymer (b) having an acid value of not less than 80 mgKOH/g and not more than 400 mgKOH/g with a water-insoluble polyfunctional epoxy compound (c), said water-based ink being excellent in storage stability and maintenanceability, and [2] a process for producing a pigment water dispersion liquid of particles of the aromatic group-containing polymer (B) containing the azomethine metal complex pigment (A).

Abstract: The present invention relates to [1] a process for producing a pigment water dispersion liquid of polymer particles containing an azomethine metal complex pigment (A), said process including the step of subjecting a mixture containing the azomethine metal complex pigment (A), an uncrosslinked aromatic group-containing polymer (b) and water to dispersion treatment using a medialess disperser at an accumulated input energy of not more than 5.0 kWh/kg, [2] a pigment water dispersion liquid containing an azomethine metal complex pigment (A) and a polymer dispersant (B), in which in an optical absorption spectrum of the pigment water dispersion liquid, a ratio of a maximum absorbance (A1max) in a wavelength range of not less than 440 nm and less than 465 nm to a maximum absorbance (A2max) in a wavelength range of not less than 420 nm and less than 440 nm [(A1max)/(A2max)] is not less than 1.000, and [3] a water-based ink for ink-jet printing, containing the aforementioned pigment water dispersion liquid.

Abstract: The present invention relates to an ink set for ink-jet printing which contains at least a water-based ink (I) and a water-based ink (II) in which the water-based ink (I) contains a pigment (A1) having a barbituric acid-derived structure, and the water-based ink (II) contains a diketopyrrolopyrrole pigment (A2), an ink-jet printing method using the ink set, and an ink-jet printed material.

Abstract: The present invention relates to [1] a water-based ink for ink-jet printing which can be prevented from suffering from increased viscosity and flocculation of the ink upon storage thereof even when used in the form of a system containing a large amount of a solvent, said water-based ink for ink-jet printing containing crosslinked polymer particles containing a pigment having an indanthrone skeleton, an organic solvent and water, in which a crosslinking rate of the crosslinked polymer is not less than 10 mol % and not more than 90 mol %, and a content of the organic solvent in the water-based ink is not less than 30% by mass and not more than 65% by mass, and [2] an ink-jet printing method including the steps of loading the water-based ink as described in the above [1] to an ink-jet printing apparatus, and ejecting the water-based ink in the form of droplets of the ink onto a printing medium to form characters or images on the printing medium.

Abstract: The present invention relates to [1] a process for producing a pigment water dispersion liquid of polymer particles containing an azomethine metal complex pigment (A), said process including the step of subjecting a mixture containing the azomethine metal complex pigment (A), an uncrosslinked aromatic group-containing polymer (b) and water to dispersion treatment using a medialess disperser at an accumulated input energy of not more than 5.0 kWh/kg, [2] a pigment water dispersion liquid containing an azomethine metal complex pigment (A) and a polymer dispersant (B), in which in an optical absorption spectrum of the pigment water dispersion liquid, a ratio of a maximum absorbance (A1max) in a wavelength range of not less than 440 nm and less than 465 nm to a maximum absorbance (A2max) in a wavelength range of not less than 420 nm and less than 440 nm [(A1max)/(A2max)] is not less than 1.000, and [3] a water-based ink for ink-jet printing, containing the aforementioned pigment water dispersion liquid.

Abstract: The present invention relates to an ink set for ink-jet printing which contains at least a water-based ink (I) and a water-based ink (II) in which the water-based ink (I) contains a pigment (A1) having a barbituric acid-derived structure, and the water-based ink (II) contains a diketopyrrolopyrrole pigment (A2), an ink-jet printing method using the ink set, and an ink-jet printed material.

Abstract: The present invention relates to [1] a water-based ink containing an azomethine metal complex pigment (A), an aromatic group-containing polymer (B), an organic solvent (D) and water, in which a mass ratio of the azomethine metal complex pigment (A) to the aromatic group-containing polymer (B) [(A)/(B)] is not less than 1.4 and not more than 4, and the aromatic group-containing polymer (B) is a crosslinked polymer obtained by crosslinking an aromatic group-containing polymer (b) having an acid value of not less than 80 mgKOH/g and not more than 400 mgKOH/g with a water-insoluble polyfunctional epoxy compound (c), said water-based ink being excellent in storage stability and maintenanceability, and [2] a process for producing a pigment water dispersion liquid of particles of the aromatic group-containing polymer (B) containing the azomethine metal complex pigment (A).

Abstract: The present invention relates to a water-based ink including a pigment, a water-insoluble polymer, an organic solvent and a surfactant, in which the organic solvent includes at least a glycol ether which has a viscosity of from 2.0 to 7.0 mPa·s and a vapor pressure from 0.01 to 7.0 hPa as measured at 20° C., and a content of a glycol ether having a viscosity of not less than 6.0 mPa·s as measured at 20° C. as a component of the glycol ether in the water-based ink is from 0 to 5% by mass; the surfactant includes a silicone-based surfactant and a content of the silicone-based surfactant in the water-based ink is from 0.005 to 0.

Abstract: The present invention relates to [1] a water-based ink for ink-jet printing which can be prevented from suffering from increased viscosity and flocculation of the ink upon storage thereof even when used in the form of a system containing a large amount of a solvent, said water-based ink for ink-jet printing containing crosslinked polymer particles containing a pigment having an indanthrone skeleton, an organic solvent and water, in which a crosslinking rate of the crosslinked polymer is not less than 10 mol % and not more than 90 mol %, and a content of the organic solvent in the water-based ink is not less than 30% by mass and not more than 65% by mass, and [2] an ink-jet printing method including the steps of loading the water-based ink as described in the above [1] to an ink-jet printing apparatus, and ejecting the water-based ink in the form of droplets of the ink onto a printing medium to form characters or images on the printing medium.

Abstract: The present invention relates to a water-based ink that exhibits excellent ejection properties, and can be prevented from suffering from reduction in a dot size of the ink during a drying step thereof even when printed on a low-water absorbing recording medium, and is capable of obtaining printed characters or images having excellent uniformity, as well as an ink-jet printing method using the water-based ink. The water-based ink includes a pigment, a water-insoluble polymer, an acetylene glycol-based nonionic surfactant (A) having HLB of not less than 0 and not more than 5, a nonionic surfactant (B) having HLB of not less than 6 and not more than 20, a polyether-modified silicone (C) having a kinematic viscosity of not less than 30 mm2/s and not more than 190 mm2/s as measured at 25° C. and an organic solvent (D), in which a weighted mean value of a boiling point of the organic solvent (D) is not lower than 150° C. and not higher than 230° C.

Abstract: The present invention provides an ink-jet printing method using a water-based ink for ink-jet printing which is excellent in quick-drying fixing properties and long-term fixing properties when printing characters or images on a low-water absorbing recording medium, as well as ejection stability. The present invention relates to [1] an ink-jet printing method of printing characters or images on a recording medium using a water-based ink for ink-jet printing, in which the recording medium has a water absorption of not more than 10 g/m2 and not less than 0 g/m2 as measured in a pure water contact time of 100 milliseconds; the water-based ink includes a pigment (A), resin particles (B), a polypropylene glycol (X) and water; and the resin particles (B) are produced by emulsion polymerization method; and [2] the aforementioned water-based ink for ink-jet printing.

Abstract: An inkjet recording method for printing an inkjet recording medium comprising an ink-receiving layer containing inorganic pigment, starch and copolymer latex on a surface of a base with inkjet ink as aqueous pigment ink, a content of the inorganic pigment being 10 g/m2 or more to 35 g/m2 or less in the ink-receiving layer, and a content of calcium carbonate being from 80% by weight or more to 100% by weight or less, the inkjet ink containing one or more selected from self dispersed pigment and pigment containing water-insoluble polymer particles, from 10% by weight or more to 48% by weight or less of a water-soluble organic solvent A having a boiling point of 230° C. or less, from 0% by weight or more to 5.0% by weight or less of a water-soluble organic solvent B having a boiling point of 280° C. or more, from 42% by weight or more to 70% by weight or less of water.

Abstract: The present invention relates to a water-based ink including a pigment, a water-insoluble polymer, an organic solvent and a surfactant, in which the organic solvent includes at least a glycol ether which has a viscosity of from 2.0 to 7.0 mPa·s and a vapor pressure from 0.01 to 7.0 hPa as measured at 20° C., and a content of a glycol ether having a viscosity of not less than 6.0 mPa·s as measured at 20° C. as a component of the glycol ether in the water-based ink is from 0 to 5% by mass; the surfactant includes a silicone-based surfactant and a content of the silicone-based surfactant in the water-based ink is from 0.005 to 0.

Abstract: The present invention relates to a water-based ink that exhibits excellent ejection properties, and can be prevented from suffering from reduction in a dot size of the ink during a drying step thereof even when printed on a low-water absorbing recording medium, and is capable of obtaining printed characters or images having excellent uniformity, as well as an ink-jet printing method using the water-based ink. The water-based ink includes a pigment, a water-insoluble polymer, an acetylene glycol-based nonionic surfactant (A) having HLB of not less than 0 and not more than 5, a nonionic surfactant (B) having HLB of not less than 6 and not more than 20, a polyether-modified silicone (C) having a kinematic viscosity of not less than 30 mm2/s and not more than 190 mm2/s as measured at 25° C. and an organic solvent (D), in which a weighted mean value of a boiling point of the organic solvent (D) is not lower than 150° C. and not higher than 230° C.

Abstract: The present invention provides an ink-jet printing method using a water-based ink for ink-jet printing which is excellent in quick-drying fixing properties and long-term fixing properties when printing characters or images on a low-water absorbing recording medium, as well as ejection stability. The present invention relates to [1] an ink-jet printing method of printing characters or images on a recording medium using a water-based ink for ink-jet printing, in which the recording medium has a water absorption of not more than 10 g/m2 and not less than 0 g/m2 as measured in a pure water contact time of 100 milliseconds; the water-based ink includes a pigment (A), resin particles (B), a polypropylene glycol (X) and water; and the resin particles (B) are produced by emulsion polymerization method; and [2] the aforementioned water-based ink for ink-jet printing.

Abstract: An inkjet recording method for printing an inkjet recording medium comprising an ink-receiving layer containing inorganic pigment, starch and copolymer latex on a surface of a base with inkjet ink as aqueous pigment ink, a content of the inorganic pigment being 10 g/m2 or more to 35 g/m2 or less in the ink-receiving layer,and a content of calcium carbonate being from 80% by weight or more to 100% by weight or less, the inkjet ink containing one or more selected from self dispersed pigment and pigment containing water-insoluble polymer particles, from 10% by weight or more to 48% by weight or less of a water-soluble organic solvent A having a boiling point of 230° C. or less, from 0% by weight or more to 5.0% by weight or less of a water-soluble organic solvent B having a boiling point of 280° C. or more, from 42% by weight or more to 70% by weight or less of water.

Abstract: The present invention relates to [1] a pigment-containing water-based ink for ink-jet printing which is free of turbidity and excellent in capability of suppressing occurrence of image unevenness (MOTTLING) when printed on a low-water absorbing recording medium, said ink including at least one acetylene glycol (A) selected from the group consisting of 2,4,7,9-tetramethyl-5-decyne-4,7-diol and the like, and a nonionic surfactant (B), a content of the component (A) in the water-based ink being not less than 1.0% by mass and not more than 3.0% by mass, and a mass ratio of the component (B) to the component (A) [(B)/(A)] being not less than 1 and not more than 3; and [2] an ink-jet printing method for printing images or characters on a low-water absorbing recording medium using said water-based ink for ink-jet printing.

Abstract: The present invention relates to [1] a pigment-containing water-based ink for ink-jet printing which is free of turbidity and excellent in capability of suppressing occurrence of image unevenness (MOTTLING) when printed on a low-water absorbing recording medium, said ink including at least one acetylene glycol (A) selected from the group consisting of 2,4,7,9-tetramethyl-5-decyne-4,7-diol and the like, and a nonionic surfactant (B), a content of the component (A) in the water-based ink being not less than 1.0% by mass and not more than 3.0% by mass, and a mass ratio of the component (B) to the component (A) [(B)/(A)] being not less than 1 and not more than 3; and [2] an ink-jet printing method for printing images or characters on a low-water absorbing recording medium using said water-based ink for ink-jet printing.