Abstract: A fluorescent water base ink for ink-jet recording contains a first fluorescent dye and a second fluorescent dye. The first fluorescent dye has a first ultraviolet absorption wavelength region in an absorption spectrum and a first fluorescence emission wavelength region in a fluorescence spectrum. The second fluorescent dye has a second ultraviolet absorption wavelength region which is different from the first ultraviolet absorption wavelength region in an absorption spectrum and a second fluorescence emission wavelength region in a fluorescence spectrum. The first fluorescent dye further has an absorption wavelength region which is different from the first ultraviolet absorption wavelength region and which overlaps at least a part of the second fluorescence emission wavelength region.

Abstract: Fluorescent water base ink for ink-jet recording contains water, a fluorescent dye having a skeleton for emitting fluorescence, and a polyol having not less than two hydroxyl groups. A distance between oxygen and oxygen of the two hydroxyl groups in the polyol is substantially equal to or longer than a length of the skeleton of the fluorescent dye. When the fluorescent dye has a xanthene skeleton, 1,5-pentanediol can be used as the polyol. The ink has the high fluorescence intensity.

Abstract: A fluorescent water base ink for ink-jet recording to be used for an ink-jet printer contains water, a pigment, a compound having primary or secondary amide group, and a fluorescent dye represented by the following formula (1): wherein R1 represents OH or N(R3)R4, R2 represents hydrogen atom or halogen atom, and each of R3 and R4 represents hydrogen atom or alkyl group. A sufficient OD value and a fluorescence value are obtained while securing the vivid color development and the excellent water resistance principally in accordance with the interaction of the fluorescent dye and the compound having the amide group.

Abstract: A water base ink for ink-jet recording contains a dispersible coloring agent, a propylene glycol ether, and a surfactant composed of a random copolymer represented by the following general formula (1):

Abstract: A water base pigment ink for ink-jet recording contains a pigment, water, and at least one of polyethylene glycol and diglycerol. The ink is solidified into a solid matter when the water is evaporated. Further, the solid matter is redissolved in the unsolidified water base pigment ink for ink-jet recording. When the ink is used, then neither clog-up of a nozzle nor discharge failure is caused, no load is imposed by the solidified ink on the maintenance system such as the wiping equipment, and the sticking performance on the paper is satisfactory.

Abstract: An ink set for ink-jet recording comprises a yellow ink, a magenta ink, and a cyan ink. Changes of colors &Dgr;EY, &Dgr;EM, &Dgr;EC of the yellow ink, the magenta ink, and the cyan ink satisfy the following relationship when the yellow ink, the magenta ink, and the cyan ink are deposited on regular paper, followed by being irradiated with light having a wavelength of 300 nm to 400 nm and an illuminance of 100 W/m2 for 30 hours by using a xenon lamp: |&Dgr;EY−&Dgr;EM|≦5, |&Dgr;EM−&Dgr;EC|≦5, |&Dgr;EC−&Dgr;EY|≦5. The ink set is excellent in color balance after the fading.

Abstract: A water base ink for ink-jet recording, which is usable for an ink-jet recording apparatus having an ink-jet head provided therein with an ink flow passage formed of nickel or nickel alloy, includes a coloring agent, water, and a water-soluble organic solvent. The ink is blended so that a current density, which is obtained within an electric potential range of −600 to +300 mV, is not more than 100 &mgr;A/cm2 when anodic polarization measurement is performed by using a reference electrode of silver/silver chloride, a counter electrode of platinum, and a working electrode of nickel or nickel alloy. The ink does not corrode any part for constituting the flow passage in the ink-jet head.

Abstract: An ink for ink-recording is provided, which makes it possible to reduce color bleed while suppressing even when recording is performed on regular paper. The ink for ink-jet recording contains water, a coloring agent, a water-soluble organic solvent, and a compound represented by the following general formula (1): wherein R represents a alkyl group having a number of carbons of 8 to 18, and x+y is not more than 10. A surface tension of the ink is controlled to 31 to 35 mN/m, which can reduce color bleed and feathering.

Abstract: A water base ink for ink-jet recording comprises water, a coloring agent, a water-soluble organic solvent, and a benzotriazole-based metal-inactivating agent and alkanolamine. When the ink is used in an ink-jet recording apparatus which has the metal member containing nickel or nickel alloy in an ink supply passage, nickel is eluted from the metal member in an amount of not more than 50 ppm. The ink makes it possible to perform stable jetting operation for a long term without causing any deterioration of metal members of a discharge head due to the metallic corrosion and the elution of nickel into the ink.

Abstract: A water base ink for ink-jet recording, which is usable for an ink-jet recording apparatus having an ink-jet head provided therein with an ink flow passage formed of nickel or nickel alloy, comprises a coloring agent, water, and a water-soluble organic solvent. The ink is blended so that a current density, which is obtained within an electric potential range of −600 to +300 mV, is not more than 100 &mgr;A/cm2 when anodic polarization measurement is performed by using a reference electrode of silver/silver chloride, a counter electrode of platinum, and a working electrode of nickel or nickel alloy. The ink does not corrode any part for constituting the flow passage in the ink-jet head.

Abstract: A water base ink for ink-jet recording comprises water, a coloring agent, a water-soluble organic solvent, and a benzotriazole-based metal-inactivating agent and alkanolamine. When the ink is used in an ink-jet recording apparatus which has the metal member containing nickel or nickel alloy in an ink supply passage, nickel is eluted from the metal member in an amount of not more than 50 ppm. The ink makes it possible to perform stable jetting operation for a long term without causing any deterioration of metal members of a discharge head due to the metallic corrosion and the elution of nickel into the ink.

Abstract: An ink for ink-jet recording comprises water; a coloring agent; an acetylene glycol/ethylene oxide adduct; and first and second polyoxyalkylene glycol-n-alkyl ethers which are different from each other. The first polyoxyalkylene glycol-n-alkyl ether is polypropylene glycol-n-butyl ether having three or more propylene oxides. Even when the recording is performed on regular paper, the color bleed is suppressed.

Abstract: A water base ink for ink-jet recording comprises water, a coloring agent, a water-soluble organic solvent, and a benzotriazole-based metal-inactivating agent and alkanolamine. When the ink is used in an ink-jet recording apparatus which has the metal member containing nickel or nickel alloy in an ink supply passage, nickel is eluted from the metal member in an amount of not more than 50 ppm. The ink makes it possible to perform stable jetting operation for a long term without causing any deterioration of metal members of a discharge head due to the metallic corrosion and the elution of nickel into the ink.

Abstract: A set comprising recording inks, with which the color bleed is reduced even when recording is performed on regular paper, is provided. The ink set for ink-jet recording comprises a black ink and a color ink, wherein each of the black ink and the color ink contains at least water, a coloring agent, and a water-soluble organic solvent, the water-soluble organic solvent contained in the black ink has a solubility parameter which is different by not less than 4 from a solubility parameter of the water-soluble organic solvent contained in the color ink, and the water-soluble organic solvent is contained abundantly in an amount next to an amount of water in each of the inks.

Abstract: An ink for ink-jet recording is provided, which makes it possible to reduce color bleed while suppressing feathering even when recording is performed on regular paper.

Abstract: An ink set for ink-jet recording comprises a yellow ink, a magenta ink, and a cyan ink.

Abstract: A set comprising recording inks, with which the color bleed is reduced even when recording is performed on regular paper, is provided. The ink set for ink-jet recording comprises a black ink and a color ink, wherein each of the black ink and the color ink contains at least water, a coloring agent, and a water-soluble organic solvent, the water-soluble organic solvent contained in the black ink has a solubility parameter which is different by not less than 4 from a solubility parameter of the water-soluble organic solvent contained in the color ink, and the water-soluble organic solvent is contained abundantly in an amount next to an amount of water in each of the inks.

Abstract: An ink-jet water-based ink set comprises a black ink and a yellow ink. The black ink contains a black dye, barium hydroxide, and purified water. The yellow ink contains a yellow dye, ammonium chloride, and purified water. When these inks are used to produce liquid drops and to record images on a recording medium with the aid of an on-demand recording head, the barium hydroxide and ammonium chloride initiate an endothermic reaction, whereby color intermixing is reduced, and adequate spraying stability is obtained.

Abstract: An ink-jet water-based ink set comprises a black ink and a yellow ink. The black ink contains a black dye, barium hydroxide, and purified water. The yellow ink contains a yellow dye, ammonium chloride, and purified water. When these inks are used to produce liquid drops and to record images on a recording medium with the aid of an on-demand recording head, the barium hydroxide and ammonium chloride initiate an endothermic reaction, whereby color intermixing is reduced, and adequate spraying stability is obtained.