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 including at least a compound represented by the following general formula (I) and organic solvents. When the organic solvents are classified by MOH/MW indicating a proportion of the molecular weight of hydroxyl group to the molecular weight of the organic solvents into an organic solvent A whose MOH/MW is 0 or more and less than 0.2, an organic solvent B whose MOH/MW is 0.2 or more and less than 0.4, and an organic solvent C whose MOH/MW is 0.4 or more and less than 1.0, the ink contains at least one organic solvent A, at least one organic solvent B and at least one organic solvent C. The at least one organic solvent A contains a nitrogen-containing organic solvent in an amount of 80.0% by mass or more of the at least one organic solvent A.

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: An ink cartridge for storing ink includes a thermal ink-jet head provided with a heating portion that generates thermal energy for discharging the ink. The heating portion has, on its surface in contact with the ink, a protective layer containing at least one of a silicon oxide, a silicon nitride, and a silicon carbide. The ink contains a substance that dissolves the protective layer and a compound represented by the following formula (1), and the content X (% by mass) of the compound of the formula (1) satisfies a relationship of 1?X?30: Formula (1) R1-A-R2, wherein A represents one selected from —S—, —S(?O)—, and —S(?O)2—, and R1 and R2 each independently represent a group selected from a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an alkenyl group, an acyl group, a carbamoyl group, a carboxyl group, and a sulfonyl group.

Abstract: An ink jet ink is provided which can retain good stability and shows superior intermittent ejection stability not only under a low-temperature, low-humidity environment but also a high-temperature, low-humidity environment even when the evaporation of water in the ink progresses. The ink jet ink includes a coloring material and water-soluble organic solvents, wherein the content of the coloring material is less than 7.0 mass %, the water-soluble organic solvents include glycerin and a branched alkanediol having hydroxyl groups at both terminals of its main chain, the content C of glycerin is 6.0 to 12.0 mass %, the content A of the branched alkanediol is 4.0 to 11.0 mass %, and the content A of the branched alkanediol and the total content B of the water-soluble organic solvents satisfy the relationship of 0.30?A/B?0.50.

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 ink jet ink is provided which contains at least a coloring material and a water-soluble organic solvent, where the water-soluble organic solvent contains a branched alkanediol having hydroxyl groups at both terminals of its main chain and at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2): R1-[A]-R2??General formula (1)

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: There is provided an ink cartridge including: a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting ink from an ejection opening, and contains the ink. In the ink cartridge, the heat generating portion has, at its surface in contact with the ink, a protective layer containing at least one selected from the group consisting of a silicon oxide, a silicon nitride, and a silicon carbide; and the ink contains at least one of a polyvalent carboxylic acid and a salt thereof, and the total content of the polyvalent carboxylic acid and the salt thereof is in the range of from 0.001 mmol/l or more to 0.5 mmol/l or less. The ink cartridge shows a small change in driving pulse and a small change in image to be outputted, and provides sufficient ejection property and sufficient printing durability.

Abstract: A mailing ink, an ink tank for mailing, an ink jet recording method for mailing and an ink jet recording apparatus for mailing that can reconcile preferable tint and visibility as indicia with readability by a 2-D bar code reader. The ink is a mailing ink used in ink jet recording. In the mailing ink, the ink tank, the ink jet recording method, and the ink jet recording apparatus, the ink provides an ‘a*’ of from ?10 to 15 and a ‘b*’ of from ?50 to ?15 according to the CIE L*a*b* color system in a printed portion obtained by applying the ink to a recording medium so as to give an application amount of ink of 4.5 mg per square inch, and provides an integrated value of reflection spectrum of 90 or lower in a wavelength region of from 380 nm to 730 nm in the printed portion.

Abstract: An image forming method using a black ink containing a pigment, a black ink containing a dye, and a reactive color ink capable of unstabilizing the dispersion state of the pigment in the black ink, wherein the method includes one of the steps of, on at least part of a region to which the black ink is to be applied, applying the reactive color ink, the black ink, and the black ink in that order so as to overlap, thereby applying these inks to a recording medium; and applying the black ink, the black ink, and the reactive color ink in that order so as to overlap, thereby applying these inks to a recording medium.

Abstract: A pigment ink is provided which is used in an ink jet recording apparatus in which ejection orifices for a pigment ink and ejection orifices for at least one type of reactive ink that destabilizes a dispersed state of pigment in the pigment ink are capped with the identical cap provided with a unit for removing an ink in the cap, achieving compatibility between bleeding resistance and reliability. Where a mixed thickening ratio upon mixing the pigment ink and the reactive ink in equal volumes is represented by Y (%) and an ejection orifice-to-ejection orifice distance between the ejection orifice for the pigment ink and the ejection orifice for the reactive ink is represented by X (mm) (provided that X>0), Y and X satisfy a specific relationship.

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 jet ink including at least a compound represented by the following general formula (I) and organic solvents. When the organic solvents are classified by MOH/MW indicating a proportion of the molecular weight of hydroxyl group to the molecular weight of the organic solvents into an organic solvent A whose MOH/MW is 0 or more and less than 0.2, an organic solvent B whose MOH/MW is 0.2 or more and less than 0.4, and an organic solvent C whose MOH/MW is 0.4 or more and less than 1.0, the ink contains at least one organic solvent A, at least one organic solvent B and at least one organic solvent C. The at least one organic solvent A contains a nitrogen-containing organic solvent in an amount of 80.0% by mass or more of the at least one organic solvent A.

Abstract: An ink cartridge includes an ink-jet head and plural liquid chambers storing inks different from each other. The minimum value A1 (g/ml) for the ink densities of the inks stored in the plural liquid chambers and the maximum value B1 (g/ml) for the ink densities of inks each obtained by evaporating 10 mass % of each of the inks stored in the plural liquid chambers satisfy the relationship of (B1?A1)/A1?0.100. A stable image can be obtained, in which, even when the ink cartridge is stored for a long time period at the time of physical distribution, or is stored for a long time period in a state of being mounted on a recording apparatus so that the stored inks are brought into a situation in which the inks are apt to evaporate, a change in color balance is small as compared to an initial state.

Abstract: A mailing ink, an ink tank for mailing, an ink jet recording method for mailing and an ink jet recording apparatus for mailing that can reconcile preferable tint and visibility as indicia with readability by a 2-D bar code reader. The ink is a mailing ink used in ink jet recording. In the mailing ink, the ink tank, the ink jet recording method, and the ink jet recording apparatus, the ink provides an ‘a*’ of from ?10 to 15 and a ‘b*’ of from ?50 to ?15 according to the CIE L*a*b* color system in a printed portion obtained by applying the ink to a recording medium so as to give an application amount of ink of 4.5 mg per square inch, and provides an integrated value of reflection spectrum of 90 or lower in a wavelength region of from 380 nm to 730 nm in the printed portion.

Abstract: An ink jet ink is provided which can retain good stability and shows superior intermittent ejection stability not only under a low-temperature, low-humidity environment but also a high-temperature, low-humidity environment even when the evaporation of water in the ink progresses. The ink jet ink includes a coloring material and water-soluble organic solvents, wherein the content of the coloring material is less than 7.0 mass %, the water-soluble organic solvents include glycerin and a branched alkanediol having hydroxyl groups at both terminals of its main chain, the content C of glycerin is 6.0 to 12.0 mass %, the content A of the branched alkanediol is 4.0 to 11.0 mass %, and the content A of the branched alkanediol and the total content B of the water-soluble organic solvents satisfy the relationship of 0.30?A/B?0.50.

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 is provided which contains at least a coloring material and a water-soluble organic solvent, where the water-soluble organic solvent contains a branched alkanediol having hydroxyl groups at both terminals of its main chain and at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2): R1-[A]-R2??General formula (1)

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).