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: 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 fluorescent water base ink for ink-jet recording includes water, a first fluorescent dye, and a second fluorescent dye. The first fluorescent dye absorbs light in a first absorption wavelength region in an ultraviolet region to emit fluorescence, and the first fluorescent dye absorbs light in a second absorption wavelength region to emit no fluorescence. The second fluorescent dye absorbs light in an absorption wavelength region in the ultraviolet region, which is different from the first absorption wavelength region of the first fluorescent dye, to emit fluorescence. A wavelength region of the fluorescence of the second fluorescent dye is not overlapped with the first absorption wavelength region of the first fluorescent dye, but at least a part of the wavelength region of the fluorescence of the second fluorescent dye is overlapped with the second absorption wavelength region. The fluorescence intensity of the ink is increased.

Abstract: The present disclosure relates to an ink-jet ink set which, in spite of using a black ink including a black pigment, may form printed matter (e.g., images) with desirable fixability to glossy paper, color balance after fading (fading stability), and/or water resistance and/or ink-jet ink sets with desirable storage stability. An ink set may include a yellow dye ink including a yellow dye, a magenta dye ink including a magenta dye, a cyan dye ink including a cyan dye and a black ink. A black ink may include a black pigment, a yellow dye, a magenta dye and a cyan dye. A black ink may have a weight ratio of the amount of the black pigment to the total amount of the yellow dye, the magenta dye, and the cyan dye of from about 30/70 to less than about 70/30 (e.g., from about 30/70 to about 70 (but not inclusive of 70)/30).

Abstract: A water base ink set for ink-jet recording includes a black ink containing water, a black pigment and a water-soluble organic solvent and a color ink containing water, a dye, and a water-soluble organic solvent. The black pigment is a negatively-chargeable and self-dispersible pigment. The dye has a fluorescein structure. The color ink further contains an alkylamine ethylene oxide adduct. The water-soluble organic solvent contained in the black ink is same as that contained in the color ink. With the ink set, not only the bleeding hardly occurs but also satisfactory discharge stability is obtained even when an ink-jet recording is performed on a regular paper.

Abstract: A water base ink set for ink-jet recording includes a black ink containing a negatively charged self-dispersing black pigment and a water-soluble polyvalent alcohol alkyl ether; and a yellow ink containing a water-soluble anionic yellow dye in which a number of counter ion or ions per one molecule is not more than 3, a surfactant based on amine represented by the following general formula (1), and a water-soluble polyvalent alcohol alkyl ether; R—N—(CH2CH2O)xH(CH2CH2O)yH??(1) wherein R represents an alkyl group or an alkenyl group having a number of carbons of 8 to 18, and x+y is 5 to 15. Accordingly, the water ink set in which no bleeding or no coagulation of the pigment occur is provided.

Abstract: An ink set for ink-jet recording comprises a pigment ink and a dye ink containing a pigment and a dye as coloring agent, respectively. The pigment ink contains water, a water-soluble organic solvent, and a negatively charged pigment wherein potassium ion and sodium ion have a total ion concentration of not more than 200 ppm, and divalent or multivalent metal ion or ions have a total ion concentration of not more than 10 ppm. The dye ink contains water, a water-soluble organic solvent, and a dye associated with a counter ion of lithium ion wherein potassium ion and sodium ion have a total ion concentration of not more than 400 ppm, and divalent or multivalent metal ion or ions have a total ion concentration of not more than 10 ppm. In the ink set, the pigment and dye inks can be used in combination without complicating a maintenance system.

Abstract: In a water base ink set for ink-jet recording including a pigment-based black ink and a dye-based yellow ink, a first water-soluble dye in which a number of counter ion or ions per one molecule is not more than 3 and a hue angle h* is 95° to 105° is used, as the dye used in the yellow ink, together with a second water-soluble dye in which a number of counter ion or ions per one molecule is not more than 3 and a hue angle h* is 75° to 85°; or 30° to 70°; or 0° to 30° or 350° to 360°. When the ink set is applied to a general ink-jet printer with a simple maintenance system, the coagulation of black pigment in the printer and the blurring or bleeding on the printing paper are prevented, thereby realizing a satisfactory and complex coloring of the dye-based yellow ink.

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: In a water base ink set for ink-jet recording, a pigment ink has a total ion concentration of lithium ion, potassium ion, and sodium ion of not less than 60 ppm and a total ion concentration of divalent or multivalent metal ion or ions of not more than 10 ppm, and a dye ink has a total ion concentration of lithium ion, potassium ion, and sodium ion of not more than 1,800 ppm and a total ion concentration of divalent or multivalent metal ion or ions of not more than 10 ppm, wherein the total ion concentration of lithium ion, potassium ion, and sodium ion of the dye ink is 3 to 25 times that of the pigment ink. Accordingly, the water base ink set in which the pigment ink and the dye ink can be reliably used in combination without complicating a maintenance system is provided.

Abstract: According embodiments of the present disclosure, a water-based ink set for ink-jet recording is provided. The ink set may contain a black ink, a cyan ink, a magenta ink and a yellow ink. Each ink may contain a polyoxyethylene alkyl ether sulfonate.

Abstract: A magenta ink for ink-jet recording contains a coloring agent, water and a water soluble organic solvent. Different types of dyes are employed as the coloring agent. In particular, a dye (1) represented by the general formula (1) is used together with at least one dye selected from the group consisting of a dye (2) represented by the general formula (2) in a free acid form, C. I. Acid Red 289 and C. I. Acid Red 52.

Abstract: An ink set for ink-jet recording is formed from a yellow ink in which C. I. Direct Yellow 132 and C. I. Direct Yellow 86 are employed, a magenta ink in which a specific pyrazolylazopyridine-based (or pyrazolylazopyrazine-based) dye and another specific dye are employed, and a cyan ink in which two specific types of copper phthalocyanine-based dyes are employed.

Abstract: A cyan ink for ink-jet recording contains a coloring agent, water and a water soluble organic solvent. Different types of dyes are employed as the coloring agent. In particular, a dye represented by the general formula (1) is used together with at least one dye selected from the group consisting of a dye represented by the general formula (2), a dye represented by the general formula (3) and C. I. Direct Blue 86. In the formulas, Pc(Cu) is a copper phthalocyanine nucleus.

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: A water base ink for ink-jet recording to be used for an ink-jet recording apparatus having an ink-jet head comprises a self-dispersing type coloring agent, water, and a water-soluble organic solvent. The surface tension of the ink is 30 to 50 mN/M, the advancing contact angle with respect to the jetting surface of the ink-jet head is not less than 65°, the receding contact angle is not less than 55°, and the difference between the advancing contact angle and the receding contact angle is not more than 20°. It is possible to jet the ink stably, it is possible to form a sharp recorded image with less blur, and it is possible to obtain the recorded image excellent in water resistance.

Abstract: A water base ink for ink-jet recording is provided, which makes it possible to secure a high recording quality with a sharp image area edge by avoiding any blurring even when recording is performed on regular paper and which has satisfactory purge restoration performance. Therefore, no bubble remains in an ink flow passage, and no discharge failure is caused. Further, the discharge operation never becomes unstable. In the water base ink for ink-jet recording, the surface tension is not less than 40 mN/m, and the amount of dissolved oxygen is not more than 4 mg/L.

Abstract: A water base ink for ink-jet recording is provided, which is excellent in time-dependent stability of ink characteristics, which can be stably jetted over a long period of time, and which makes it possible to perform the high quality recording. The water base ink for ink-jet recording contains a self-dispersing type water-insoluble particulate coloring agent, a compound represented by the following formula (1), a surfactant having a nitrogen atom in a molecule, water, and a water-soluble organic solvent, wherein a surface tension is 30 to 50 mN/m, and a ratio of change of the surface tension after storage at 60° C. for 2 weeks is less than 5%: R1—O—(CH2CH2O)x—SO3Na??(1) wherein R1 represents an alkyl group and x is 20 to 30 in the formula (1).

Abstract: A water base ink set for ink-jet recording includes a water base ink which contains an acid dye, and a water base ink which contains a basic dye. The water base ink contains a polymer which has an average molecular weight of 3,000 to 20,000 and which is represented by the following formula (1): wherein X represents H or COONa, and Y represents H, COONa, SO3Na, or CH2OR in the formula (1). R represents a substituted group having SO3Na with carbon atom or atoms of a number of 1 to 5. When the ink containing the acid dye and the ink containing the basic dye are mixed with each other, then the head discharge section is prevented from any clog-up, and it is possible to perform the stable jetting operation.

Abstract: A fluorescent water base ink for ink-jet recording contains a fluorescent dye having a xanthene skeleton, and a glycol. In the fluorescent dye, the difference in hydrophilic index log P is not less than 2.6 between a substituent bonded to C-9 carbon atom of the xanthene skeleton and other portion of the fluorescent dye than the substituent bonded to the C-9 carbon atom. The glycol has a distance between hydroxyl groups substantially equivalent to or longer than an interatomic distance between atoms directly bonded to C-3 and C-6 carbon atoms of the xanthene skeleton of the fluorescent dye, respectively. It is assumed that the glycol is coordinated with the xanthene skeleton in a bridge form to increase the fluorescence intensity by increasing the electron density of the xanthene skeleton. The ink having high fluorescence intensity and in which the fluorescence intensity is not lowered in a time-dependent manner is provided.