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 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 98.5/1.5 or less.

Abstract: An ink jet ink includes a pigment and a polyurethane polymer having units derived from a polyisocyanate, a polyol, and a diol having an acid group, and in the ink jet ink described above, an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less, the unit derived from the polyisocyanate includes a unit derived from a compound represented by the following general formula (I), and the proportion of the unit derived from the compound represented by the general formula (I) in the unit derived from the polyisocyanate is 90 percent by mole or less.

Abstract: An aqueous ink to be used together with a pigment ink containing a pigment and a polymer, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: An ink jet ink including a pigment and an ABC triblock polymer, wherein the above-described ABC triblock polymer is formed from an A block having an aryl group, a B block having a unit represented by the following general formula (1), and a C block having a unit represented by the following general formula (2).

Abstract: An ink jet ink providing an image having excellent lightfastness and having sticking resistance and intermittent ejection stability. The ink jet ink is characterized by containing at least a compound represented by the following general formula (I) and a compound represented by the following general formula (II).

Abstract: An ink jet ink containing a pigment and a polyurethane polymer, wherein the polyurethane polymer has units derived from a polyol having no acid group and having the carbon number of 13 or more and 250 or less, a diol having an acid group and having the carbon number of 1 or more and 7 or less, a polyol having a siloxane structure, and a polyisocyanate, and an acid value of the polyurethane polymer is 40.0 mgKOH/g or more and 80.0 mgKOH/g or less.

Abstract: The present invention provides an ink jet ink, which gives a superior lightfastness to an ink image, has a superior sticking resistance and intermittent ejection stability, and gives a preferable color tone to the image. The ink includes an azo-based dye represented by formula (I) and a water-soluble organic solvent represented by bis(2-hydroxyethyl)sulfone represented by formula (II).

Abstract: An aqueous ink used together with a black ink containing a self-dispersion pigment, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the self-dispersion pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: An inkjet ink contains at least one coloring material selected from the group of C. I. Acid Yellow 23, C. I. Direct Yellow 86, C. I. Direct Yellow 132, and C. I. Direct Yellow 173, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium.

Abstract: An ink jet ink contains a pigment and a polyurethane polymer. The polyurethane polymer contains units derived from a polyisocyanate, a polyol, a compound having a carboxy group, and a compound having a sulfo group, and an acid value of the polyurethane polymer is 20 mgKOH/g or more and 100 mgKOH/g or less.

Abstract: An inkjet ink contains at least one coloring material selected from the group of C. I. Direct Violet 107, C. I. Acid Red 14, C. I. Acid Red 52, C. I. Acid Red 87, C. I. Acid Red 289 and C. I. Reactive Red 180, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium. The ratio of the content in the inkjet ink of the compound expressed by general formula (I) to the total content of coloring materials in the inkjet ink is in the range of 15.0% by mass or more to 40.0% by mass or less.

Abstract: Provided herein is an aqueous ink, which is excellent in both image density and fixing ability irrespective of the kind of a recording medium even when the volume of an ink droplet is small and has such excellent properties that white stripes are not caused even when high-speed recording is conducted. The aqueous ink comprises at least water, a water-soluble organic solvent, a water-insoluble coloring material, a surfactant and a poor medium for the water-insoluble coloring material and/or a salt. The dynamic surface tension of the aqueous ink at a lifetime of 50 milliseconds determined by a maximum bubble pressure method is higher than 47 mN/m, and the dynamic surface tension at a lifetime of 5,000 milliseconds determined by the maximum bubble pressure method is 38 mN/m or lower.

Abstract: In an ink set having a plurality of inks, the ink set has at least a pigment ink and a dye ink. The pigment ink contains at least water, a surfactant, a self-dispersion pigment, and a poor medium for self-dispersion pigment and/or a salt; a dynamic surface tension of the pigment ink at a lifetime of 50 milliseconds is higher than 47 mN/m. The dye ink contains at least water, a surfactant and a dye. An ink set is provided which can obtain images having a high image density and a superior bleeding resistance without regard to the types of recording mediums.

Abstract: An inkjet ink contains at least one coloring material selected from the group of C. I. Direct Violet 107, C. I. Acid Red 14, C. I. Acid Red 52, C. I. Acid Red 87, C. I. Acid Red 289 and C. I. Reactive Red 180, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium. The ratio of the content in the inkjet ink of the compound expressed by general formula (I) to the total content of coloring materials in the inkjet ink is in the range of 15.0% by mass or more to 40.0% by mass or less.

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 inkjet ink contains at least one coloring material selected from the group of C. I. Acid Yellow 23, C. I. Direct Yellow 86, C. I. Direct Yellow 132, and C. I. Direct Yellow 173, and a coloring material including a compound expressed by general formula (I): wherein in the formula (I), each M independently represents hydrogen, an alkali metal, ammonium, or an organic ammonium.

Abstract: An ink to be applied to a recording head having a common liquid chamber, pressure chambers developing pressure applied to the liquid, individual channels through which the liquid is introduced into the pressure chambers from the common liquid chamber, and a group of nozzles which communicate with the pressure chambers and eject the liquid, where first nozzles having short individual channels and second nozzles having long ones are alternately arranged at arrangement intervals of less than 30 ?m along one side or sides of the common liquid chamber, contains an aqueous medium, a surfactant and a coloring material. The aqueous medium consists of water and a water-soluble organic compound containing at least one alkanediol and has a surface tension of from 40 mN/m or more to less than 60 mN/m in an environment of temperature 25° C. and humidity 50%.

Abstract: An ink having a cyan color is provided which can form images excellent in ozone resistance in such a high level as to exceed anticipation and having a preferable color tone. The ink includes at least two coloring materials of a first coloring material and a second coloring material, wherein the first coloring material is a compound having a copper phthalocyanine skeleton with a specific structure and the second coloring material is a compound having a copper phthalocyanine skeleton with a specific structure that is different from the first coloring material.

Abstract: An ink jet ink providing an image having excellent lightfastness and having sticking resistance and intermittent ejection stability. The ink jet ink is characterized by containing at least a compound represented by the following general formula (I) and a compound represented by the following general formula (II).

Abstract: The present invention provides an ink jet ink, which gives a superior lightfastness to an ink image, has a superior sticking resistance and intermittent ejection stability, and gives a preferable color tone to the image. The ink includes an azo-based dye represented by formula (I) and a water-soluble organic solvent represented by bis(2-hydroxyethyl)sulfone represented by formula (II).