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 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 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: 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 cartridge includes a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting the ink from an ejection opening, in which: the heat generating portion has, on 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 a substance that dissolves the protective layer and a compound represented by (R2)nA—. . . —N(R1)C(O)R3(R4)—(A) where A represents alkylene or alkenylene which forms a ring with a nitrogen atom, a carbonyl group and R3, R1 and R4 each represent hydrogen atom, hydroxyl, alkyl, alkenyl, acyl, carbamoyl, carboxyl or sulfonyl, R2 represents a group bonded to an arbitrary carbon atom of A and represents hydrogen atom, hydroxyl, alkyl, alkenyl, acyl, carbamoyl, carboxyl or sulfonyl, n represents 0 to 4, and R3 represents carbon or nitrogen atom, and a content X (% by mass) of the compound satisfies 1?X?30.

Abstract: There are provided: a liquid ink for ink jet including: water; a coloring material; 1,5-pentanediol; and a humectant, in which the content of 1,5-pentanediol is 3 mass % or more and 15 mass % or less, and the total of the content of 1,5-pentanediol and the content of the humectant is 10 mass % or more and 40 mass % or less; and an ink jet recording method using the ink.

Abstract: There is provided a cyan ink for ink jet and an ink jet recording method using the same, which can reduce both reciprocating color uneven and beading without impairing fastness property even when a yellow ink or a magenta ink containing a specific coloring material with excellent fastness property is used. In the ink jet recording method using a yellow ink and a cyan ink, or a magenta ink and a cyan ink, the yellow ink and the magenta ink contain a specific coloring material and have a surface tension of 33.0 mN/m or more and 36.0 mN/m or less, and the cyan ink contains a specific phthalocyanine compound, contains 1,5-pentanediol as an organic solvent, and has a surface tension of 32.9 mN/m or more and 35.4 mN/m or less.

Abstract: An ink set is provided which can suppress bleeding irrespective of the type of recording medium. The ink set includes a plurality of aqueous inks each containing a dye, and has at least a first aqueous ink containing a dye, wherein the difference between the dynamic surface tension of the first aqueous ink at a lifetime of 50 milliseconds and the dynamic surface tension of the first aqueous ink at a lifetime of 500 milliseconds is 7 mN/m or more; and, between the first aqueous ink and at least one type of aqueous ink except the first aqueous ink included in the ink set, dynamic surface tension ?a (mN/m) of an ink A having relatively higher lightness at a lifetime of 500 milliseconds and dynamic surface tension ?b (mN/m) of an ink B having relatively lower lightness at a lifetime of 500 milliseconds satisfy ?5?(?a??b)?3.

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 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: R1-A-R2 ??Formula (1) 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 recording ink comprising at least a copper phthalocyanine dye represented by the following general formula (1) and a compound represented by the following general formula (2):

Abstract: The invention provides 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 for mailing, the ink jet recording method for mailing and the ink jet recording apparatus for mailing, 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 cartridge includes a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting the ink from an ejection opening, in which: the heat generating portion has, on 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 a substance that dissolves the protective layer and a compound represented by (R2)nA—. . . —N(R1)C(O)R3(R4)—(A) where A represents alkylene or alkenylene which forms a ring with a nitrogen atom, a carbonyl group and R3, R1 and R4 each represent hydrogen atom, hydroxyl, alkyl, alkenyl, acyl, carbamoyl, carboxyl or sulfonyl, R2 represents a group bonded to an arbitrary carbon atom of A and represents hydrogen atom, hydroxyl, alkyl, alkenyl, acyl, carbamoyl, carboxyl or sulfonyl, n represents 0 to 4, and R3 represents carbon or nitrogen atom, and a content X (% by mass) of the compound satisfies 1?X?30.

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: There are provided: a liquid ink for ink jet including: water; a coloring material; 1,5-pentanediol; and a humectant, in which the content of 1,5-pentanediol is 3 mass % or more and 15 mass % or less, and the total of the content of 1,5-pentanediol and the content of the humectant is 10 mass % or more and 40 mass % or less; and an ink jet recording method using the ink.

Abstract: There is provided a cyan ink for ink jet and an ink jet recording method using the same, which can reduce both reciprocating color uneven and beading without impairing fastness property even when a yellow ink or a magenta ink containing a specific coloring material with excellent fastness property is used. In the ink jet recording method using a yellow ink and a cyan ink, or a magenta ink and a cyan ink, the yellow ink and the magenta ink contain a specific coloring material and have a surface tension of 33.0 mN/m or more and 36.0 mN/m or less, and the cyan ink contains a specific phthalocyanine compound, contains 1,5-pentanediol as an organic solvent, and has a surface tension of 32.9 mN/m or more and 35.4 mN/m or less.

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: An ink comprising yellow colorants and a colorant having a phthalocyanine skeleton, in which the yellow colorants are at least a colorant represented by the following general formula I and C.I.

Abstract: An ink comprising yellow colorants and a colorant having a phthalocyanine skeleton, in which the yellow colorants are at least a colorant represented by the following general formula I and C.I. Direct Yellow 132.

Abstract: An ink jet recording ink comprising at least a copper phthalocyanine dye represented by the following general formula (1) and a compound represented by the following general formula (2):