Abstract: An ink for ink-jet recording is provided, which makes it possible to obtain vivid recorded matters by satisfying both of the prevention of the feathering and the prevention of the bleeding even when the recording is performed on regular paper. The ink for ink-jet recording contains a self-dispersing type microparticulate coloring agent, a surfactant, and water. When the surface tension is plotted in the vertical axis, and the concentration of the surfactant is plotted in the horizontal axis, then the correlation between the surface tension and the concentration of the surfactant can be represented by a correlation curve which has one inflection point and which has two local maximum points of curvature on both sides of the inflection point one by one. Further, the ink for ink-jet recording contains the surfactant at a concentration which is higher than a concentration corresponding to the local maximum point of the curvature on the low concentration side.

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-based ink for ink jetting and ink jet recording method, in which stable jetting, clearness of the recorded matter, high density recording, water resistance, and friction resistance are well-balanced, and being useful for ink for various types of ink jet recording. After 5% of the water soluble colored resin comprising 5,5?-dimethylhydantoinformaldehyde resin and color index number basic red 1:1 and 10% of polyethyleneglycol (average molecular weight 200) and 6% of triethyleneglycolmonometylether and 79% of pure water are fully stirred to be mixed, the mixture is filtered with a membrane filter of 0.8 ?m thickness to become ink. Experimental evaluation using the recording head regarding jetting stability, jetting response, quality of the recorded images, friction resistance against various recording materials, and water resistance against various recording materials is made, and good results are obtained.

Abstract: An ink for ink-jet recording contains tripropylene glycol normal butyl ether or dipropylene glycol normal propyl ether, an acrylic polymer, a water-insoluble coloring agent, and water. The ink simultaneously satisfies the straight travel stability of ink droplets during the discharge with an ink-jet recording apparatus, the recovery performance upon introduction into a recording head of the ink-jet recording apparatus, the fixation performance of printed matters, and the drying performance after the printing.

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 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: An ink for ink-jet recording is provided in which C. I. Direct Blue 199 and a thiazole-based compound are used. In this ink, about 1 mol % to about 20 mol % of the total counter ions in C. I. Direct Blue 199 are ammonium ions or organic ammonium ions.

Abstract: An ink for ink-jet recording is provided in which copper phthalocyanine dyes and a thiazole-based compound are used. In this ink, the mildew resistant properties are not impaired, and the ink exhibits excellent ozone resistance. Furthermore, the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording, as copper phthalocyanine dyes, two types of dyes are used together with a thiazole-based compound. Furthermore, about 1 mol % to about 20 mol % of the total counter ions in the two types of copper phthalocyanine dyes are ammonium ions or organic ammonium ions.

Abstract: An ink for ink-jet recording is provided in which a copper phthalocyanine dye is used and a thiazole-based compound is also used. In this ink, the mildew resistant properties are not impaired. Furthermore, the ink exhibits excellent ozone resistance, and the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording containing the copper phthalocyanine dye and the thiazole-based compound, the used copper phthalocyanine dye has a specific structure, and about 1 mol % to about 20 mol % of the total counter ions of the dye are ammonium ions or organic ammonium ions.

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: An ink for ink-jet recording is provided in which a copper phthalocyanine dye is used and a thiazole-based compound is also used. In this ink, the mildew resistant properties are not impaired. Furthermore, the ink exhibits excellent ozone resistance, and the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording containing the copper phthalocyanine dye and the thiazole-based compound, the used copper phthalocyanine dye has a specific structure, and about 1 mol % to about 20 mol % of the total counter ions of the dye are ammonium ions or organic ammonium ions.

Abstract: An ink for ink-jet recording is provided in which copper phthalocyanine dyes and a thiazole-based compound are used. In this ink, the mildew resistant properties are not impaired, and the ink exhibits excellent ozone resistance. Furthermore, the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording, as copper phthalocyanine dyes, two types of dyes are used together with a thiazole-based compound. Furthermore, about 1 mol % to about 20 mol % of the total counter ions in the two types of copper phthalocyanine dyes are ammonium ions or organic ammonium ions.

Abstract: An ink for ink-jet recording is provided in which C. I. Direct Blue 199 and a thiazole-based compound are used. In this ink, about 1 mol % to about 20 mol % of the total counter ions in C. I. Direct Blue 199 are ammonium ions or organic ammonium ions.