Abstract: Provided herein is an aqueous ink, which is excellent in both image density and fixing ability irrespective of the kind of a recording medium even when the volume of an ink droplet is small and has such excellent properties that white stripes are not caused even when high-speed recording is conducted. The aqueous ink comprises at least water, a water-soluble organic solvent, a water-insoluble coloring material, a surfactant and a poor medium for the water-insoluble coloring material and/or a salt. The dynamic surface tension of the aqueous ink at a lifetime of 50 milliseconds determined by a maximum bubble pressure method is higher than 47 mN/m, and the dynamic surface tension at a lifetime of 5,000 milliseconds determined by the maximum bubble pressure method is 38 mN/m or lower.

Abstract: To relate to a head liquid which is supplied to efficiently remove ink residues and the like which are attached to the surface of an inkjet head provided with ejection openings through which an ink containing a color material is ejected. In a case where a nonvolatile solvent such as glycerin is used as the head liquid, the nonvolatile solvent absorbs moisture, and thereby an extremely large change in mass is exhibited. As a result, the above supply amount is varied. To solve the problem, it was found that the previous mixing of water with the nonvolatile solvent can provide a smaller change in mass than that in a case where the nonvolatile solvent by itself is caused to absorb moisture. Accordingly, a mixture prepared by mixing the nonvolatile solvent and water in an appropriate predetermined ratio is used as a head liquid.

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: In an ink set having a plurality of inks, the ink set has at least a pigment ink and a dye ink. The pigment ink contains at least water, a surfactant, a self-dispersion pigment, and a poor medium for self-dispersion pigment and/or a salt; a dynamic surface tension of the pigment ink at a lifetime of 50 milliseconds is higher than 47 mN/m. The dye ink contains at least water, a surfactant and a dye. An ink set is provided which can obtain images having a high image density and a superior bleeding resistance without regard to the types of recording mediums.

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 includes 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 in 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 relates to an aqueous ink, particularly an aqueous ink suitable for ink jet recording. The ink is an aqueous ink comprising a modified pigment having organic groups chemically attached to the surface of a particle of the pigment and an aqueous medium which is a dispersant of the pigment, wherein the above-described organic group includes a reaction product of a functional group chemically attached to the surface of the pigment directly or via another atomic group with a copolymer of an ionic monomer and a hydrophobic monomer.

Abstract: A surface reforming method capable of efficiently carrying out a sustainable, even reforming treatment on a prescribed surface part of an element, a surface treatment liquid to be employed for the above-described method, and an element having a reformed surface treated by the above-described method. A part of the surface of an element is subjected to the reforming treatment by providing the object surface with a polymer, which is different from a constituent material of the object surface and comprises a first part having a functional group and a second part having an interfacial energy different from that of the functional group and approximately equal to the surface energy of the object surface and orienting the second part of the polymer toward the object surface and orienting the first part in a direction different from the object surface.

Abstract: In a method of cleaning an ejection face by supplying a head liquid on a surface (ejection face) of an inkjet head provided with ink ejection outlets, and then by performing wiping operations thereon, an ink residue on the ejection face is efficiently and surely removed from the ejection face to achieve a sufficient cleaning thereon. For this purpose, a first wiping operation is first performed such that a wiper (9A) is relatively largely bent, and slidingly contacts the ejection face at an abdomen thereof to efficiently perform the application, stirring and mixing of the head liquid. Then, a second wiping operation is performed such that an edge portion of the top end of a wiper (9B) slidingly contacts the surface to efficiently scrape the mixture of the head liquid and the ink residue.

Abstract: An aqueous ink to be used together with a pigment ink containing a pigment and a polymer, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: In an ink set having a plurality of inks, the ink set has at least a pigment ink and a dye ink. The pigment ink contains at least water, a surfactant, a self-dispersion pigment, and a poor medium for self-dispersion pigment and/or a salt; a dynamic surface tension of the pigment ink at a lifetime of 50 milliseconds is higher than 47 mN/m. The dye ink contains at least water, a surfactant and a dye. An ink set is provided which can obtain images having a high image density and a superior bleeding resistance without regard to the types of recording mediums.

Abstract: An ink jet recording ink tank includes: an ink retention member, which to hold ink exerts a negative pressure through capillary force; and ink, which is retained in the ink retention member, for which a dynamic surface tension in a lifetime of 50 msec, obtained by a maximum bubble pressure method, is higher than an interfacial tension of the ink retention member, a dynamic surface tension in a lifetime of 5000 msec is lower than the interfacial tension of the ink retention member, and a difference between the dynamic surface tension in the lifetime of 50 msec and the dynamic surface tension in the lifetime of 5000 msec is equal to or greater than 8 mN/m.

Abstract: An ink set is provided which can suppress bleeding irrespective of the type of recording medium. The ink set includes a plurality of aqueous inks each containing a dye, and has at least a first aqueous ink containing a dye, wherein the difference between the dynamic surface tension of the first aqueous ink at a lifetime of 50 milliseconds and the dynamic surface tension of the first aqueous ink at a lifetime of 500 milliseconds is 7 mN/m or more; and, between the first aqueous ink and at least one type of aqueous ink except the first aqueous ink included in the ink set, dynamic surface tension ?a (mN/m) of an ink A having relatively higher lightness at a lifetime of 500 milliseconds and dynamic surface tension ?b (mN/m) of an ink B having relatively lower lightness at a lifetime of 500 milliseconds satisfy ?5?(?a??b)?3.

Abstract: An aqueous ink used together with a black ink containing a self-dispersion pigment, wherein the aqueous ink contains a reactive component for destabilizing the dispersion state of the self-dispersion pigment, the dynamic surface tension of the aqueous ink at a lifetime of 30 milliseconds is 41 mN/m or more, and the dynamic surface tension of the aqueous ink at a lifetime of 500 milliseconds is from 28 mN/m or more to 38 mN/m or less as determined by a maximum bubble pressure method.

Abstract: A surface reforming method capable of efficiently carrying out a sustainable, even reforming treatment on a prescribed surface part of an element, a surface treatment liquid to be employed for the above-described method, and an element having a reformed surface treated by the above-described method. A part of the surface of an element is subjected to the reforming treatment by providing the object surface with a polymer, which is different from a constituent material of the objet surface and comprises a first part having a functional group and a second part having an interfacial energy different from that of the functional group and approximately equal to the surface energy of the object surface and orienting the second part of the polymer toward the object surface and orienting the first part in a direction different from the object surface.

Abstract: An ink set for ink jet recording includes a black ink and a plurality of color inks of different colors. The black ink contains a pigment as a coloring material. The color ink having the highest brightness among the plurality of color inks has the highest surface tension among the plurality of color inks. The difference in surface tension between the black ink and the color ink having the highest brightness is 2 dyn/cm (mN/m) or less.

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: In a construction which uses a wiping member to wipe off ink adhering to the surface of an ink jet print head formed with ink ejection nozzles, it is realized that a desired wiping performance in any environment without requiring a large space to accommodate a liquid supplied to the wiping member for satisfactory wiping. To this end, a cooling unit is used which can produce water by cooling the atmosphere. This cooling unit is operated to produce water, which is brought into contact with and transferred onto the wiping member before the wiping member performs wiping.

Abstract: A water-based ink of the present invention comprises water, a plurality of different water-soluble organic solvents, and a water-insoluble coloring material, wherein the above water-soluble organic solvents consist of a good solvent to the above water-insoluble coloring material and a poor solvent to the above water-insoluble coloring material, and the total amount (% by mass) of the good solvents in the ink is represented by A and the total amount (% by mass) of the poor solvent in the ink is represented by B, the ratio of A to B ranges from 10:5 to 10:30 both inclusive, and when the respective Ka values of the above water-soluble organic solvents are determined by the Bristow method and compared with each other, a water-soluble organic solvent having the largest Ka value is the poor solvent. The pigment ink has a sufficiently large area factor even with a small amount of ink and provides an image of high OD.

Abstract: A water-based ink of the present invention comprises water, a plurality of different water-soluble organic solvents, and a water-insoluble coloring material, wherein the above water-soluble organic solvents consist of a good solvent to the above water-insoluble coloring material and a poor solvent to the above water-insoluble coloring material, and the total amount (% by mass) of the good solvents in the ink is represented by A and the total amount (% by mass) of the poor solvent in the ink is represented by B, the ratio of A to B ranges from 10:5 to 10:30 both inclusive, and when the respective Ka values of the above water-soluble organic solvents are determined by the Bristow method and compared with each other, a water-soluble organic solvent having the largest Ka value is the poor solvent. The pigment ink has a sufficiently large area factor even with a small amount of ink and provides an image of high OD.

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.