Abstract: Provided is an ink cartridge for containing a water-based ink for ink-jet recording including a pigment, water, and a nonionic surfactant, the ink cartridge including a remaining ink detecting portion detecting an amount of remaining ink on the basis of whether or not light is transmitted therethrough. The remaining ink detecting portion is formed of a hydrophobic resin containing a water-repellent material in the proportion of 0.14 wt % to 10 wt %.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, glycerol and polyethylene glycol #200 as water-soluble organic solvents and a polymeric dispersant. The ink will preferably have a ratio of glycerol to polyethylene glycol 200 within the range of from 2:1 to 3.5 1. The water-based ink preferably includes C.I. Pigment Blue 60 as a colorant and provides good printing stability and good storage stability. Tests show the inks to have good jettability.

Abstract: Provided is an ink cartridge for containing a water-based ink for ink-jet recording including a pigment, water, and a nonionic surfactant, the ink cartridge including a remaining ink detecting portion detecting an amount of remaining ink on the basis of whether or not light is transmitted therethrough. The remaining ink detecting portion is formed of a hydrophobic resin containing a water-repellent material in the proportion of 0.14 wt % to 10 wt %.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, specifically including C.I. Pigment Blue 60 and C.I. Acid Blue 90, with water and a water-soluble organic solvent. The blue ink provide an image which has good water resistance and high optical density.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, specifically including C.I. Pigment Blue 60 and C.I. Acid Blue 90, with water and a water-soluble organic solvent. The blue ink provide an image which has good water resistance and high optical density.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, glycerol and polyethylene glycol #200 as water-soluble organic solvents and a polymeric dispersant. The ink will preferably have a ratio of glycerol to polyethylene glycol 200 within the range of from 2:1 to 3.5 1. The water-based ink preferably includes C.I. Pigment Blue 60 as a colorant and provides good printing stability and good storage stability. Tests show the inks to have good jettability.

Abstract: A water base ink for ink-jet recording contains self-dispersible carbon black as a coloring agent. The total content of an organic acid having a number of carbon or carbons of 1 to 6 and a salt of the organic acid is not more than 400 ppm. The organic acid having a number of carbon or carbons of 1 to 6 includes monocarboxylic acid, dicarboxylic acid and oxy acid, and the salt of the organic acid includes salts of these acids. When the water base ink is used in an ink-jet recording apparatus, the discharge stability of the ink is improved.

Abstract: A water base ink for ink-jet recording contains self-dispersible carbon black as a coloring agent. The total content of an organic acid having a number of carbon or carbons of 1 to 6 and a salt of the organic acid is not more than 400 ppm. The organic acid having a number of carbon or carbons of 1 to 6 includes monocarboxylic acid, dicarboxylic acid and oxy acid, and the salt of the organic acid includes salts of these acids. When the water base ink is used in an ink-jet recording apparatus, the discharge stability of the ink is improved.

Abstract: A water base ink for ink-jet recording contains self-dispersible carbon black as a coloring agent. The total content of an organic acid having a number of carbon or carbons of 1 to 6 and a salt of the organic acid is not more than 400 ppm. The organic acid having a number of carbon or carbons of 1 to 6 includes monocarboxylic acid, dicarboxylic acid and oxy acid, and the salt of the organic acid includes salts of these acids. When the water base ink is used in an ink-jet recording apparatus, the discharge stability of the ink is improved.

Abstract: An ink set for ink-jet recording includes a pigment-based ink containing a negatively chargeable and self-dispersible pigment as a coloring agent and a dye-based ink containing an anionic dye as a coloring agent, and the ink set satisfies the following expression (1): Dci<1.1×Pci+0.0001??(1) wherein “Dci” represents an amount of counter ion (mol/g) of the anionic dye contained in the dye-based ink, and “Pci” represents an amount of counter ion (mol/g) of the self-dispersible pigment contained in the pigment-based ink. The pigment aggregation can be greatly suppressed, and the high quality printing can be stably performed when the ink set for ink-jet recording composed of the pigment-based ink and the dye-based ink is carried on an ink-jet printer provided with a conventional maintenance system that is simple and at low cost.

Abstract: The water-based ink set for ink-jet recording includes a cyan ink and a blue ink, or a cyan ink and a green ink. The cyan ink is a light cyan ink having a lightness (L*) of about 60 or more in the L*a*b* colorimetric system. A normal cyan ink having a lightness (L*) of about 60 or less in the L*a*b* calorimetric system is not included in the ink set.

Abstract: A water-based ink set for ink-jet recording is provided. According to this ink set, graininess in a low density printed part can be reduced without reducing a color reproduction range in red and magenta directions in a high density printed part. In addition, the color reproduction range in the red direction can be extended to improve the vividness of red color. The water-based ink set for ink-jet recording includes a magenta ink and a red ink. The magenta ink is a light magenta ink having a lightness (L*) of about 50 or more in the L*a*b* colorimetric system. Preferably, the ink set further includes a light cyan ink having a lightness (L*) of about 60 or more and a blue ink and/or a green ink.

Abstract: A water base pigment ink for ink-jet recording contains a pigment, a propylene glycol derivative which has a saturation vapor pressure of 2 to 10 hPa and an octanol-water distribution coefficient log P of 0 to 1.35, and dipropylene glycol-n-propyl ether. The propylene glycol derivative is contained in the ink by 0.25 to 1.5% by weight, and the dipropylene glycol-n-propyl ether is contained in the ink by 0.5 to 1% by weight. The ink is excellent in the paper surface drying performance. Further, it is possible to avoid the occurrence of the feathering and the blank stripes in letters.

Abstract: A water based ink set for ink-jet recording includes a yellow ink, a magenta ink, a cyan ink, a black ink, and a red ink and/or a blue ink each including at least a coloring agent, water and a water soluble organic solvent. In the water based ink set, a water soluble dye is employed as the coloring agent of each of the yellow ink, the magenta ink and the cyan ink, and a pigment is employed as the coloring agent of each of the black ink and the red ink and/or the blue ink. In an ink-jet recording method employing the water based ink set for ink-jet recording, the red ink and the magenta ink are employed together for a magenta-ink-recording portion, and the blue ink and the cyan ink are employed together for a cyan-ink-recording portion.

Abstract: A water based ink set for ink-jet recording has a yellow ink, a magenta ink and a cyan ink each having at least a coloring agent, water and a water soluble organic solvent. The coloring agent of each of the black ink and the red ink is a pigment and the coloring agent of each of the yellow ink, the magenta ink and the cyan ink is a water soluble dye. The black ink and the red ink each have a dynamic surface tension at a lifetime of 100 ms of 40 mN/m or more and 45 mN/m or less as measured by a maximum bubble pressure method at 25° C.

Abstract: A water based ink set for ink-jet recording, capable of reducing graininess, is composed of a combination of a diluting ink and one or more coloring inks. The diluting ink contains at least water and a water soluble organic agent and does not substantially contain a coloring agent, and the coloring ink contains at least a coloring agent, water and a water soluble organic solvent. In this ink set, the dynamic surface tension of the diluting ink is set to be higher than that of the coloring ink.

Abstract: A water base ink for ink-jet recording is provided, which makes it possible to perform the discharge operation stably and highly accurately for a long period of time without deteriorating a metal, for example, due to corrosion and/or dissolution even when the ink makes contact with the metal composed of nickel or an alloy containing nickel for a long period of time. The water base ink for ink-jet recording is usable for an ink-jet recording apparatus provided with an ink-jet head having a metal member which is composed of nickel or the alloy containing nickel and which is disposed at least in an ink supply passage for supplying the ink to a discharge section. The water base ink for ink-jet recording contains potassium p-tert-butylbenzoate, a coloring agent which is dispersible or soluble in water, water, and a water-soluble organic solvent.

Abstract: The water-based ink set for ink-jet recording includes a cyan ink and a blue ink, or a cyan ink and a green ink. The cyan ink is a light cyan ink having a lightness (L*) of about 60 or more in the L*a*b* colorimetric system. A normal cyan ink having a lightness (L*) of about 60 or less in the L*a*b* calorimetric system is not included in the ink set.

Abstract: A water-based ink set for ink-jet recording is provided. According to this ink set, graininess in a low density printed part can be reduced without reducing a color reproduction range in red and magenta directions in a high density printed part. In addition, the color reproduction range in the red direction can be extended to improve the vividness of red color. The water-based ink set for ink-jet recording includes a magenta ink and a red ink. The magenta ink is a light magenta ink having a lightness (L*) of about 50 or more in the L*a*b* colorimetric system. Preferably, the ink set further includes a light cyan ink having a lightness (L*) of about 60 or more and a blue ink and/or a green ink.

Abstract: A water based ink set for ink-jet recording has a yellow ink, a magenta ink and a cyan ink each having at least a coloring agent, water and a water soluble organic solvent. The coloring agent of each of the black ink and the red ink is a pigment and the coloring agent of each of the yellow ink, the magenta ink and the cyan ink is a water soluble dye. The black ink and the red ink each have a dynamic surface tension at a lifetime of 100 ms of 40 mN/m or more and 45 mN/m or less as measured by a maximum bubble pressure method at 25° C.