Abstract: The present invention aims to provide an ink which has a sufficiently large area factor even in a small ink droplet quantity and can obtain images having a high image density, and further has a superior storage stability. According to the present invention, a cyan ink is provided which is used in an ink set having four kinds of aqueous inks consisting of a cyan ink, a magenta ink, a yellow ink and a black ink in which each ink comprises at least water, a water-insoluble coloring material, and a plurality of water-soluble organic solvents having a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material, wherein, the ratio B1/A1 is from 0.5 or more to 3.

Abstract: An aqueous ink comprising water, a water-soluble organic solvent and at least two pigments. The aqueous ink is used together with a reaction liquid containing a reactive component that reacts with the aqueous ink to cause aggregation or gelation of the aqueous ink. The at least two pigments have a difference in precipitation value to the reaction liquid of 0.2 or less.

Abstract: An aqueous ink, by which stable ink-jet recording can be conducted irrespective of printing environment, a substantially even image having abrasion resistance can be formed, no image soiling is caused even upon double-side printing, and a high-quality image improved in unclearness at a contour portion of the image and free from occurrence of color bleed can be provided, is provided. The aqueous ink is an aqueous ink used in a system that a reaction liquid containing at least a polyvalent metal and an aqueous ink containing at least a pigment dispersion, in which a pigment is dispersed with an anionic polymer dispersant, are used to form an image, wherein the aqueous ink satisfies specific condition.

Abstract: A reaction solution to be used for image recording with an ink containing a coloring material in a dissolved or dispersed state in order to achieve a high level of image density with stability, wherein the reaction solution contains a polyvalent metal ion and an organic solvent to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink, has a pH of 2 or higher, and has a buffering action for pH, wherein the buffering action means it can maintain pH variation within the range of 0.5 before and after the addition of 1.0 ml of a 0.1 N aqueous lithium hydroxide solution to 50 ml of the reaction solution.

Abstract: Provided is a cyan ink applicable to an ink set having four kinds of aqueous inks composed of the cyan ink, a magenta ink, a yellow ink, and a black ink each containing water; a water-insoluble coloring material; and plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. The content of the water-insoluble coloring material in the cyan ink is in a specific range, and the ratio B1/A1 between the good medium and the poor medium is also in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents is the poor medium. The ratio A/B between the good medium and the poor medium in an arbitrary aqueous ink in the ink set except the cyan ink and B1/A1 satisfy a specific relationship.

Abstract: A cyan ink applicable to an ink set has plurality of aqueous inks each containing at least: water; a water-insoluble coloring material; and plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. A ratio of a poor medium to a good medium in the cyan ink is in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents is the poor medium. A ratio of a poor medium to a good medium in an arbitrary aqueous ink in the ink set except the cyan ink and the ratio of the poor medium to the good medium in the cyan ink satisfy a specific relationship.

Abstract: Disclosed is an aqueous ink comprising at least water, a plurality of water-soluble organic solvents and a coloring material. The coloring material is a pigment, and, it contains a pigment particle having at least one ionic group bonded to a surface of the pigment particle directly or via another atomic group. The plurality of water-soluble organic solvents have a good medium or good mediums for the pigment and a poor medium or poor mediums for the pigment. The poor medium does not solvate perfectly or substantially the pigment. The ionic group undergoes perfectly or substantially no ionic dissociation in the poor medium. Also, among the respective Ka values of the plurality of water-soluble organic solvents as determined by the Bristow method, the Ka value of the poor medium is maximum.

Abstract: The present invention can sufficiently suppress curling phenomenon of a recorded product and facilitate handling of a printed product produced by using plain paper, in particular. The present invention provides a printing medium coating solution including water and a water-retentive, water-soluble organic compound, wherein the water-soluble organic compound includes only a water-soluble organic compound showing a difference of 36% or less between the water retention ability at a temperature of 23° C. and a humidity of 45% and the water retention ability at a temperature of 30° C. and a humidity of 80%; and the content of the water-soluble organic compound is 15 mass % or more with respect to the total amount of the printing medium coating solution.

Abstract: The present invention can sufficiently suppress curling phenomenon of a recorded product and facilitate handling of a printed product produced by using plain paper, in particular. The present invention provides a printing medium coating solution including water and a water-retentive, water-soluble organic compound, wherein the water-soluble organic compound includes only a water-soluble organic compound showing a difference of 36% or less between the water retention ability at a temperature of 23° C. and a humidity of 45% and the water retention ability at a temperature of 30° C. and a humidity of 80%; and the content of the water-soluble organic compound is 15 mass % or more with respect to the total amount of the printing medium coating solution.

Abstract: A reaction liquid containing a reactive substance that reacts with at least one component in an ink composition containing a coloring material in a dispersed state, in which the reactive substance is a polyvalent metal compound having multiple reactive sites in one molecule, a set of ink and a reaction liquid, and an image recording method for performing image recording by means of the set.

Abstract: Provided is an ink set including a plurality of inks each of which contains a water-insoluble coloring material and enabling ink-jet record images to be stably formed. The ink set includes first to nth aqueous inks for ink-jet recording, each of the aqueous inks containing a water-insoluble coloring material, an aqueous medium and a dispersant for dispersing the pigment in the aqueous medium, and a water-soluble organic compound, wherein the first to the nth aqueous inks are different from each other in pigment concentration based on the total weight of the each ink; and the first to the nth aqueous inks have the same or substantially the same viscosity at an actual usage temperature (T1).

Abstract: Provided is a cyan ink applicable to an ink set having four kinds of aqueous inks composed of the cyan ink, a magenta ink, a yellow ink, and a black ink each containing water; a water-insoluble coloring material; and plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. The content of the water-insoluble coloring material in the cyan ink is in a specific range, and the ratio B1/A1 between the good medium and the poor medium is also in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents is the poor medium. The ratio A/B between the good medium and the poor medium in an arbitrary aqueous ink in the ink set except the cyan ink and B1/A1 satisfy a specific relationship.

Abstract: A recording method is provided which enables formation of an image with high image density and low graininess. The recording is conducted by using a recording method using a first aqueous ink for higher-density recording and a second aqueous ink for lower-density recording, characterized in that the first aqueous ink comprises at least water, a water-insoluble coloring material, and plurality of water-soluble organic solvents, the plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material, the ratio B/A in the second aqueous ink being less than the ratio B/A the first aqueous ink, where A denotes the total content (mass %) of good medium based on the total mass of the aqueous ink and B denotes the total content (mass %) of poor medium based on the total mass of the aqueous ink; and the second aqueous ink has the same hue as the first aqueous ink.

Abstract: The present invention aims to provide an ink which has a sufficiently large area factor even in a small ink droplet quantity and can obtain images having a high image density, and further has a superior storage stability. According to the present invention, a cyan ink is provided which is used in an ink set having four kinds of aqueous inks consisting of a cyan ink, a magenta ink, a yellow ink and a black ink in which each ink comprises at least water, a water-insoluble coloring material, and a plurality of water-soluble organic solvents having a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material, wherein, the ratio B1/A1 is from 0.5 or more to 3.

Abstract: An aqueous ink comprises water, a water-insoluble coloring material, and plurality of water-soluble organic solvents and the plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. The ratio of the content of the poor medium and the content of the good medium is in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents is the poor medium. When the aqueous ink is in contact with a specific reaction liquid, the dissolution state or dispersed state of the water-insoluble coloring material in the ink is made unstable. As a result, an image which has a sufficiently large area factor even with a small amount of ink droplets and is excellent in image density, bleeding resistance, and fixability can be obtained.

Abstract: Disclosed is an aqueous ink comprising at least water, a plurality of water-soluble organic solvents and a coloring material. The coloring material is a pigment, and, it contains a pigment particle having at least one ionic group bonded to a surface of the pigment particle directly or via another atomic group. The plurality of water-soluble organic solvents have a good medium or good mediums for the pigment and a poor medium or poor mediums for the pigment. The poor medium does not solvate perfectly or substantially the pigment. The ionic group undergoes perfectly or substantially no ionic dissociation in the poor medium. Also, among the respective Ka values of the plurality of water-soluble organic solvents as determined by the Bristow method, the Ka value of the poor medium is maximum.

Abstract: A cyan ink applicable to an ink set has plurality of aqueous inks each containing at least: water; a water-insoluble coloring material; and plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. A ratio of a poor medium to a good medium in the cyan ink is in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents is the poor medium. A ratio of a poor medium to a good medium in an arbitrary aqueous ink in the ink set except the cyan ink and the ratio of the poor medium to the good medium in the cyan ink satisfy a specific relationship.

Abstract: Provided is an ink which comprises an aqueous medium and a coloring material dispersed in the aqueous medium with a dispersant, where the coloring material is contained in an amount of at most 1% by weight with respect to the total weight of the ink, and the ratio (B/P ratio) of the dispersant to the coloring material is larger than 1.

Abstract: An aqueous ink, by which stable ink-jet recording can be conducted irrespective of printing environment, a substantially even image having abrasion resistance can be formed, no image soiling is caused even upon double-side printing, and a high-quality image improved in unclearness at a contour portion of the image and free from occurrence of color bleed can be provided, is provided. The aqueous ink is an aqueous ink used in a system that a reaction liquid containing at least a polyvalent metal and an aqueous ink containing at least a pigment dispersion, in which a pigment is dispersed with an anionic polymer dispersant, are used to form an image, wherein the aqueous ink satisfies specific condition.

Abstract: To suppress curling phenomenon of a recording medium to which a liquid composition is applied while securing ejection stability. A liquid composition for used in an image recording method including the steps of applying an ink containing a colorant in a dissolved state or a dispersed state to a recording medium and applying to the recording medium a liquid composition which destabilizes the dissolved state or the dispersed state of the colorant in the ink by coming into contact with the ink, the liquid composition including at least a polyvalent metal ion, water, and water-soluble organic compounds 1 and 2, in which a content X (mass %) of the water-soluble organic compound 1 in the liquid composition is 15 mass % or more, and the content X (mass %) of the water-soluble organic compound 1 in the liquid composition and a content Y (mass %) of the water-soluble organic compound 2 in the liquid composition satisfy a specific relationship.