Abstract: Provided is Ink including a pigment, a resin, a water-soluble organic solvent, and water, wherein a solid content of first liquid as prepared by diluting the ink 500-fold with water and by adding CaCl2 at a concentration of 1.5 mM has a rate of aggregation of 1.5 nm/second or less; and a solid content of second liquid as prepared, after the ink has been stored at 60° C. for 2 weeks, by diluting the ink 500-fold with water and by adding CaCl2 at a concentration of 5 mM has a rate of aggregation of 2.0 nm/second or more.

Abstract: An aqueous inkjet ink of the present invention contains: a solvent A; a resin particle; and a color material, wherein the solvent A is an alcohol having a water solubility at 20° C. of 5% by mass or less, the vapor pressure at 20° C. of 0.5 mmHg or less, and the surface tension at 20° C. of 30 mN/m or more; the ratio of the content (% by mass) of the solvent A to the water solubility (% by mass) of the solvent A at 20° C. is 0.7 or more and 7.0 or less; and the SP value of the resin particle is 8.1 (cal/cm3)0.5 or more and 9.7 (cal/cm3)0.5 or less.

Abstract: An image printing method includes the step of applying at least two inks that contain a color pigment, resin particles, and water onto a printing medium by ejecting the inks using an inkjet printing apparatus. The inkjet printing apparatus includes at least two printing heads sequentially arranged in a printing medium conveying direction, the printing medium is normal paper or a high-absorbency printing medium, a rub fastness additive is contained in a first ink ejected from at least a first printing head that is located at an uppermost-stream position in the printing medium conveying direction of the at least two printing heads, and the content of the rub fastness additive in an ink ejected from a printing head that is located at a position downstream of the first printing head in the printing medium conveying direction is less than the content of the rub fastness additive in the first ink.

Abstract: An aqueous ink for ink jet includes a coloring material, a solvent, and a surfactant having an HLB value of 9.0 or less. The solvent includes a solvent A having a solubility in water at 20° C. of 5.00 g/100 g-H2O or less and a solvent B other than the solvent A. The solvent A includes an alcohol having a vapor pressure at 20° C. of 0.5 mmHg or less and a surface tension of 30.0 mN/m or more. The content of the alcohol in the aqueous ink is 0.7 or more times the solubility in water at 20° C. in an equal amount to the aqueous ink. The solvent B has a partition coefficient (PB) satisfying the following equation (1). 1.44 Log PA?0.1x?3.4?Log PB??0.

Abstract: An ink including a first pigment, a second pigment, and water. The first pigment satisfies condition 1, the second pigment satisfies condition 2, and the content (% by mass) of the first pigment relative to the content (% by mass) of the second pigment based on a total mass of the ink is 1.7 times or more to 8.0 times or less in terms of mass ratio. Condition 1: When, to a pigment dispersion liquid containing the first pigment, calcium chloride is added so as to give a predetermined concentration, the particle diameter increase rate of the solid content is 2.0 nm/second or more. Condition 2: When, to a pigment dispersion liquid containing the second pigment, hydrochloric acid is added so as to give a predetermined concentration, the particle diameter increase rate of the solid content is 0.5 nm/second or less.

Abstract: There is provided an image recording method including applying a first ink and a second ink, each of which contains a surfactant and the like, to a recording medium. Critical micelle concentration c1 (mass %) of the surfactant and concentration c2 (mass %) of the surfactant in each ink satisfy a relationship of “c1×2?c2”; an HLB value of the surfactant is smaller than 13; content V1 (mass %) of the surfactant in the first ink is larger than content V2 (mass %) of the surfactant in the second ink.

Abstract: An ink of this invention contains a self-dispersible pigment having a phosphonic acid group bonded directly or through another atomic group to the surface of the self-dispersible pigment, polyurethane resin particles, a monovalent inorganic salt, and water.

Abstract: An ink including a self-dispersible pigment, acrylic resin particles, a water-soluble organic solvent, and water. The self-dispersible pigment includes a phosphonic-acid-based self-dispersible pigment having a phosphonic acid group bonded directly or via another atomic group to a surface of particles of the pigment. The acrylic resin particles are formed of an acrylic resin containing a constituent unit derived from an ester-bond-containing monomer. The content of the constituent unit derived from the ester-bond-containing monomer in the acrylic resin is 60 mol % or more based on the total of the acrylic resin.

Abstract: An ink includes a self-dispersing pigment, polyurethane resin particles, a surfactant, and water. The self-dispersing pigment is a pigment having a phosphonic acid group bonded directly or via another atomic group to a surface thereof.

Abstract: Provided is an ink containing a pigment, a water-soluble organic solvent, and a surfactant., and having a viscosity at 25° C. of 5 mPa·s or more. The ink has a static surface tension of 30.5 mN/m or more to 35.0 mN/m or less, which is measured at 25° C. by a Wilhelmy method. The ink also has a dynamic surface tension at a bubble life time of 150 msec of 30.5 mN/m or more to 37.0 mN/m or less, which is measured at 25° C. by a maximum bubble pressure method.

Abstract: Provided is Ink including a pigment, a resin, a water-soluble organic solvent, and water, wherein a solid content of first liquid as prepared by diluting the ink 500-fold with water and by adding CaCl2 at a concentration of 1.5 mM has a rate of aggregation of 1.5 nm/second or less; and a solid content of second liquid as prepared, after the ink has been stored at 60° C. for 2 weeks, by diluting the ink 500-fold with water and by adding CaCl2 at a concentration of 5 mM has a rate of aggregation of 2.0 nm/second or more.

Abstract: An ink including a self-dispersible pigment, acrylic resin particles, a water-soluble organic solvent, and water. The self-dispersible pigment includes a phosphonic-acid-based self-dispersible pigment having a phosphonic acid group bonded directly or via another atomic group to a surface of particles of the pigment. The acrylic resin particles are formed of an acrylic resin containing a constituent unit derived from an ester-bond-containing monomer. The content of the constituent unit derived from the ester-bond-containing monomer in the acrylic resin is 60 mol % or more based on the total of the acrylic resin.

Abstract: There is provided an ink including a pigment, resin particles, a surfactant, water-soluble organic compound, and water, in which: the content of the water-soluble organic compounds is 35 mass % or less based on a total mass of the ink; the water-soluble organic compound contains a first water-soluble organic compound being liquid at 25° C. and having a surface tension at 25° C.

Abstract: Provided is an ink containing a pigment, a water-soluble organic solvent, and a surfactant represented by the following general formula (1), and having a viscosity at 25° C. of 5 mPa·s or more. The ink has a static surface tension of 27.1 mN/m or more and 35.0 mN/m or less, which is measured at 25° C. by a Wilhelmy method. The ink also has a dynamic surface tension at a bubble life time of 150 msec of 30.5 mN/m or more and 37.0 mN/m or less, which is measured at 25° C. by a maximum bubble pressure method.

Abstract: An ink jet image recording method includes applying a first ink and a second ink onto a recording medium. The first ink contains a surfactant expressed by general formula (1) with a content of V1 percent by mass relative to the total mass of the first ink and a liquid X being the portion other than the surfactant, and the second ink contains the surfactant with a content of V2 percent by mass lower than V1 relative to the total mass of the second ink and a liquid Y being the portion other than the surfactant. The liquids X and Y satisfy the specific requirement, and when liquids X? and Y? are prepared by adding the surfactant to the liquid X and Y, respectively, to a content of V2 percent by mass relative to the total mass of the respective liquids, the liquids X? and Y? satisfy a specific requirement.

Abstract: An ink containing a self-dispersing pigment, polyurethane resin particles, a surfactant, and water, wherein the self-dispersing pigment is a pigment having a phosphonate group bonded directly or via another atomic group to the surface of the pigment, wherein the polyurethane resin particles have an anionic functional group content of 0.1 mmol/g or more and 0.4 mmol/g or less on the surfaces of the polyurethane resin particles and have a volume average particle size of 10.0 nm or more and 50.0 nm or less, and the surfactant includes a surfactant represented by a general formula (1), wherein the amount of the surfactant represented by the general formula (1) is 0.05 times or more and 1.00 times or less the amount of the polyurethane resin particles.

Abstract: Provided is an ink containing a self-dispersible pigment, an acrylic resin particle, a surfactant, a water-soluble organic solvent, and water. The surfactant includes a fluorinated surfactant represented by Formula (1) and having an HLB value determined by a Griffin method of 11 or less. The water-soluble organic solvent includes at least one water-soluble organic solvent selected from a specific group, and the total content of the water-soluble organic solvents of the specific group is 4 times or more the total content of the water-soluble organic solvents other than the solvents of the specific group. The total content of the self-dispersible pigment and the acrylic resin particle is 10% by mass or less based on the total mass of the ink.

Abstract: An image recording method includes a conveyance process for conveying a recording medium and an ink-applying process for applying a first ink and a second ink to the recording medium, wherein the first ink and the second ink contain a surfactant represented by Formula (1), the amount of the surfactant represented by Formula (1) in the first ink is greater than the amount of the surfactant represented by Formula (1) in the second ink, and a liquid X prepared by removing the surfactant represented by Formula (1) from the first ink and a liquid Y prepared by removing the surfactant represented by Formula (1) from the second ink satisfy a particular condition.

Abstract: An ink includes a self-dispersing pigment, polyurethane resin particles, a surfactant, and water. The self-dispersing pigment is a pigment having a phosphonic acid group bonded directly or via another atomic group to a surface thereof.

Abstract: An ink of this invention contains a self-dispersible pigment having a phosphonic acid group bonded directly or through another atomic group to the surface of the self-dispersible pigment, polyurethane resin particles, a monovalent inorganic salt, and water.