Abstract: Provided is an aqueous ink for ink jet including: pigments; a urethane resin; and a silicone-based surfactant. The pigments include a first pigment and a second pigment, the first pigment is a naphthol AS-based azo pigment and the second pigment is a quinacridone-based pigment. The urethane resin is a water-soluble urethane resin having a unit derived from a polyisocyanate, a unit derived from a polyol having no acid group and a unit derived from a polyol having an acid group. The silicone-based surfactant is at least one kind selected from the group consisting of compounds represented by the following respective general formulae (1) to (3), has a weight-average molecular weight of 800 or more to 10,000 or less and has an HLB value measured by Griffin's method of 4 or more.

Abstract: Provided is an aqueous ink that is suppressed from causing mist and is excellent in storage stability. The aqueous ink is an aqueous ink to be ejected from a recording head of an ink jet system through an action of thermal energy. The aqueous ink includes a first surfactant and a second surfactant. The first surfactant contains a compound represented by the following general formula (1) (in the general formula (1), “m” and “n” each independently represent an integer of 1 or more and satisfy a relationship of m+n?10, and “a” represents an integer of 10 or more to 20 or less). The second surfactant contains an acetylene glycol compound.

Abstract: Provided is an ink jet recording method including recording an image on a recording medium through use of an ink jet recording apparatus, the inkjet recording apparatus including: an aqueous ink; a recording head including an ink flow path in which the aqueous ink flows and including an ejection orifice configured to eject the aqueous ink; and a recovery mechanism configured to recover an ejection state of the aqueous ink from the ejection orifice by applying a pressure to the ink flow path inside the recording head. The aqueous ink contains resin particles each dyed with a basic dye exhibiting fluorescence and a water-soluble resin. The resin particles are each formed of a resin having an anionic group-containing unit. The water-soluble resin has an anionic group-containing unit.

Abstract: Provided is an ink jet recording method including using an ink jet recording apparatus, the ink jet recording apparatus including: an aqueous ink containing resin particles each dyed with a fluorescent dye. A plurality of nozzle arrays include a first nozzle array and a second nozzle array arranged in a predetermined direction so as to be displaced from each other in such a manner that end nozzles in the nozzle arrays adjacent to each other form an overlapping portion in a direction intersecting the predetermined direction. The aqueous ink is ejected from overlapping nozzles at the overlapping portion while the nozzles are allocated to the first nozzle array and the second nozzle array. An application time difference of the aqueous ink ejected from the overlapping nozzles is 20 milliseconds or less.

Abstract: Provided is an aqueous ink that enables the recording of images having high optical density and excellent toughness and has excellent reliability. An aqueous ink for ink jet includes a pigment, a resin having an anionic group, a salt and a water-soluble organic solvent. The pigment is a self-dispersible pigment in which an anionic group is bonded to the particle surface of carbon black directly or through another atomic group, the resin has a weight-average molecular weight of 20,000 or less, the water-soluble organic solvent includes glycerol and an additional solvent other than glycerol, and the content (% by mass) of the additional solvent relative to the content (% by mass) of glycerol in terms of mass ratio is 0.6 times or less.

Abstract: To provide an aqueous ink that can suppress the dissolution of silicon or a silicon compound contained in a recording head, can be stably, continuously ejected for a long time, and enables the recording of an image having excellent glossiness. An aqueous ink for ink jet includes a pigment, a resin dispersant for dispersing the pigment, an alkanolamine and a urethane resin. The pigment is a solid solution containing C.I. Pigment Red 122 and C.I. Pigment Violet 19, and the proportion (% by mass) of the C.I. Pigment Red 122 is 10% by mass or more to 90% by mass or less based on the total mass of the solid solution.

Abstract: To provide an aqueous ink for ink jet enabling the recording of an image having excellent character quality and excellent highlighter resistance immediately after the recording. An aqueous ink for ink jet includes a pigment and a urethane resin. The urethane resin has a unit derived from a polyisocyanate, a unit derived from a polyol having no acid group and a unit derived from a polyol having an acid group, the proportion of a unit derived from the polyol having an acid group present at the molecular terminal relative to the whole unit derived from the polyol having an acid group is 30% or less, and the aqueous ink has a dynamic surface tension of 55 mN/m or more at a lifetime of 10 msec.

Abstract: To provide an aqueous ink that can suppress the dissolution of silicon or a silicon compound contained in a recording head, can be stably, continuously ejected for a long time, and enables the recording of an image having excellent glossiness. An aqueous ink for ink jet includes a pigment, a resin dispersant for dispersing the pigment, an alkanolamine and a urethane resin. The pigment is a solid solution containing C.I. Pigment Red 122 and C.I. Pigment Violet 19, and the proportion (% by mass) of the C.I. Pigment Red 122 is 10% by mass or more to 90% by mass or less based on the total mass of the solid solution.

Abstract: To provide an aqueous ink for ink jet enabling the recording of an image having excellent character quality and excellent highlighter resistance immediately after the recording. An aqueous ink for ink jet includes a pigment and a urethane resin. The urethane resin has a unit derived from a polyisocyanate, a unit derived from a polyol having no acid group and a unit derived from a polyol having an acid group, the proportion of a unit derived from the polyol having an acid group present at the molecular terminal relative to the whole unit derived from the polyol having an acid group is 30% or less, and the aqueous ink has a dynamic surface tension of 55 mN/m or more at a lifetime of 10 msec.

Abstract: Provided is an aqueous ink that enables the recording of images having high optical density and excellent toughness and has excellent reliability. An aqueous ink for ink jet includes a pigment, a resin having an anionic group, a salt and a water-soluble organic solvent. The pigment is a self-dispersible pigment in which an anionic group is bonded to the particle surface of carbon black directly or through another atomic group, the resin has a weight-average molecular weight of 20,000 or less, the water-soluble organic solvent includes glycerol and an additional solvent other than glycerol, and the content (% by mass) of the additional solvent relative to the content (% by mass) of glycerol in terms of mass ratio is 0.6 times or less.

Abstract: An ink used for an inkjet recording method for discharging the ink from a recording head by an action of thermal energy contains self-dispersing carbon black, a polyurethane polymer having an acid value of 40 mg KOH/g or more, and an acryl polymer having an acid value of 100 mg KOH/g or more and 200 mg KOH/g or less.

Abstract: An aqueous ink for ink jet contains a urethane resin. The urethane resin has a unit derived from a polyether polyol and a unit containing an acidic group. The acid value of the urethane resin is 40 to 140 mg KOH/g. The molar ratio of urethane bonds/urea bonds is 80.0/20.0 or more. Some of the acidic groups in the urethane resin are neutralized with particular neutralizing agents.

Abstract: The invention provides an ink containing a polyurethane polymer which has units respectively derived from a polyisocyanate, a polyether polyol having no acid group and a diol having an acid group and has an acid value of 40 mg KOH/g or more and 140 mg KOH/g or less, a carbon black and at least one antioxidant selected from compounds represented by the general formulae (1) to (3).

Abstract: An ink jet recording method for recording an image onto a recording medium by ejecting an aqueous ink containing a resin from an ejection orifice through use of an ink jet recording apparatus including a recording head having a water-repellent face subjected to water-repellent treatment as an ejection orifice face provided with an ejection orifice; a wiping unit configured to wipe the water-repellent face; and a heating unit configured to heat the water-repellent face, the ink jet recording method including a heating step of wiping the water-repellent face with the wiping unit after heating the water-repellent face with the heating unit and continuously heating the water-repellent face until after the wiping of the water-repellent face.

Abstract: An ink jet ink contains a polyurethane polymer and a self-dispersing pigment. The polyurethane polymer has units derived from a polyisocyanate, a polyol having no acid group, and a diol having an acid group. The molar ratio of the percentage of the urethane bond in the polyurethane polymer to the percentage of the urea bond in the polyurethane polymer is 85.0/15.0 or more and 100.0/0 or less. The ink jet ink may be capable of producing an image having high optical density, scratch resistance, and highlighter resistance, and which has excellent ink ejection stability and can reduce image deflection caused by face wetting.

Abstract: The invention provides an ink containing a self-dispersion pigment in which a phosphonic acid group is bonded directly or through another atomic group to the surface thereof and a polyurethane polymer, wherein the surface charge amount of the self-dispersion pigment is 0.25 mmol/g or more and 0.42 mmol/g or less, and the polyurethane polymer has units respectively derived from a polyisocyanate, a polyether polyol having no acid group and a diol having an acid group.

Abstract: An ink jet recording method for recording an image onto a recording medium by ejecting an aqueous ink containing a resin from an ejection orifice through use of an ink jet recording apparatus including a recording head having a water-repellent face subjected to water-repellent treatment as an ejection orifice face provided with an ejection orifice; a wiping unit configured to wipe the water-repellent face; and a heating unit configured to heat the water-repellent face, the ink jet recording method including a heating step of wiping the water-repellent face with the wiping unit after heating the water-repellent face with the heating unit and continuously heating the water-repellent face until after the wiping of the water-repellent face.

Abstract: An aqueous ink for ink jet contains a urethane resin. The urethane resin has a unit derived from a polyether polyol and a unit containing an acidic group. The acid value of the urethane resin is 40 to 140 mg KOH/g. The molar ratio of urethane bonds/urea bonds is 80.0/20.0 or more. Some of the acidic groups in the urethane resin are neutralized with particular neutralizing agents.

Abstract: An ink used for an inkjet recording method for discharging the ink from a recording head by an action of thermal energy contains self-dispersing carbon black, a polyurethane polymer having an acid value of 40 mg KOH/g or more, and polyethylene glycol.

Abstract: An ink jet ink contains a polyurethane polymer and a pigment. The polyurethane polymer has units derived from a polyisocyanate, a polyether polyol having no acid group, and a diol having an acid group. The pigment is dispersed using a polymer other than the polyurethane polymer. The molar ratio of the percentage of the urethane bond in the polyurethane polymer to the percentage of the urea bond in the polyurethane polymer is 85.0/15.0 or more and 100.0/0 or less.