Abstract: The present invention provides an ink that can achieve image characteristics for recording an image having excellent optical density, bleeding resistance, and white blur resistance and also can achieve reliability that provides excellent sticking resistance to a recording head. The ink is one for ink jet containing a first pigment and second pigment. The first pigment is a self-dispersible pigment to a surface of a particle of which a first functional group containing a phosphonic acid group is bonded. The second pigment is a self-dispersible pigment to a surface of a particle of which a second functional group not containing a phosphonic acid group but containing an anionic group other than the phosphonic acid group, and further containing another atomic group is bonded. The introduced amount of the functional group of the second pigment is 0.25 mmol/g or more.

Abstract: An ink jet recording apparatus is provided which includes a recording unit including a recording head having a surface provided with an ejection opening therein, an aqueous ink that is ejected from the ejection opening to record an image on a recording medium, a protection unit including a covering member that covers the surface having the ejection opening, and a recovery unit separate from the covering member, having no member that scrapes the ink deposited in the ink receiving member or sucks the ink from the ejection opening. The recovery unit includes an ink receiving member that receives waste ink discharged from the ejection opening according to preliminary ejection data, directly from the ejection opening without interposing any other member. The aqueous ink contains a self-dispersible pigment containing the carboxyl group or the sulfonate group.

Abstract: The invention provides provide an ink jet ink exhibiting such an excellent ejection property that when an ink containing a polymer capable of improving the scratch resistance of a recorded article is used, the deviation of the ink-droplet impact point on a recording medium is prevented. The ink jet ink contains a polymer and a surfactant, wherein the acid value of the polymer is from 100 mg KOH/g or more to 220 mg KOH/g or less, the weight-average molecular weight of the polymer is from 3,000 or more to 10,000 or less, and the surfactant has a structure represented by the following formula (1) wherein n is a numerical value of from 3 or more to 27 or less, and m is a numerical value of from 16 or more to 31 or less.

Abstract: Provided is an ink for ink jet including a first pigment and a second pigment. Each of the first pigment and the second pigment comprises a self-dispersible carbon black in which a functional group containing two phosphonic acid groups is bonded to a particle surface. The average particle size of the first pigment is smaller than the average particle size of the second pigment. The introduced amount of the functional group of the first pigment is higher than the introduced amount of the functional group of the second pigment.

Abstract: An ink jet recording apparatus is provided which includes a recording unit including a recording head having a surface provided with an ejection opening therein, an aqueous ink that is ejected from the ejection opening to record an image on a recording medium, a protection unit including a covering member that covers the surface having the ejection opening, and a recovery unit separate from the covering member, having no member that scrapes the ink deposited in the ink receiving member or sucks the ink from the ejection opening. The recovery unit includes an ink receiving member that receives waste ink discharged from the ejection opening according to preliminary ejection data, directly from the ejection opening without interposing any other member. The aqueous ink contains a self-dispersible pigment containing the carboxyl group or the sulfonate group.

Abstract: Provided is an ink for ink jet including a first pigment and a second pigment. Each of the first pigment and the second pigment comprises a self-dispersible carbon black in which a functional group containing two phosphonic acid groups is bonded to a particle surface. The average particle size of the first pigment is smaller than the average particle size of the second pigment. The introduced amount of the functional group of the first pigment is higher than the introduced amount of the functional group of the second pigment.

Abstract: The present invention provides an ink that can achieve image characteristics for recording an image having excellent optical density, bleeding resistance, and white blur resistance and also can achieve reliability that provides excellent sticking resistance to a recording head. The ink is one for ink jet containing a first pigment and second pigment. The first pigment is a self-dispersible pigment to a surface of a particle of which a first functional group containing a phosphonic acid group is bonded. The second pigment is a self-dispersible pigment to a surface of a particle of which a second functional group not containing a phosphonic acid group but containing an anionic group other than the phosphonic acid group, and further containing another atomic group is bonded. The introduced amount of the functional group of the second pigment is 0.25 mmol/g or more.

Abstract: Disclosed herein are an ink containing a self-dispersible pigment and a salt, wherein the self-dispersible pigment is a pigment to the surface of a particle of which a functional group containing at least a group having a hydrogen bonding property and two phosphonic acid groups is bonded, counter ions of the two phosphonic acid groups containing one of K+ and NH4+; the salt is constituted by combining at least one cation of K+ and NH4+ with at least one anion selected from the group consisting of Cl?, Br?, I?, ClO?, ClO2?, ClO3?, ClO4?, NO2?, NO3?, SO42?, CO32?, HCO3?, HCOO?, (COO?)2, COOH(COO?), CH3COO?, C2H4 (COO?)2, C6H5COO?, C6H4(COO?)2, PO43?, HPO42? and H2PO4?; a cation concentration in the ink is 0.04 mol/L or more; and the viscosity of a liquid obtained by evaporating 15% by mass of the ink is less than 3.5 mPa·s at 25° C.

Abstract: An ink jet ink including a self-dispersible pigment, a salt, a polyoxyethylene alkyl ether and a water-soluble organic solvent. The self-dispersible pigment is a pigment to a surface of a particle of which a functional group containing at least a phosphonic acid group is bonded, the introduced amount of the functional group bonded to the self-dispersible pigment is 0.10 to 0.33 mmol/g. The salt is constituted by combining a specific cation with a specific anion. The value (Concentration of anion)×(Valence number of anion) of the salt in the ink is 0.005 to 0.06 mol/L. The water-soluble organic solvent includes glycerol, the content of which in the ink is 35% to 78% by mass based on the total content of the water-soluble organic solvent in the ink.

Abstract: An ink cartridge including a housing formed with a resin and an ink stored in the housing, wherein the resin includes a white mica composition; the ink includes a salt and a self-dispersible pigment having a functional group that contains two phosphonic acid groups and is bonded to the particle surface thereof; the salt includes a specific cation and a specific anion; and an amount of calcium in the ink after the ink is preserved in the housing at 60° C. for 2 months is 10.0 ppm or less.

Abstract: Disclosed herein are an ink containing a self-dispersible pigment and a salt, wherein the self-dispersible pigment is a pigment to the surface of a particle of which a functional group containing at least a group having a hydrogen bonding property and two phosphonic acid groups is bonded, counter ions of the two phosphonic acid groups containing one of K+ and NH4+; the salt is constituted by combining at least one cation of K+ and NH4+ with at least one anion selected from the group consisting of Cl?, Br?, I?, ClO?, ClO2?, ClO3?, ClO4?, NO2?, NO3?, SO42?, CO32?, HCO3?, HCOO?, (COO?)2, COOH(COO?), CH3COO?, C2H4 (COO?)2, C6H5COO?, C6H4(COO?)2, PO43?, HPO42? and H2PO4?; a cation concentration in the ink is 0.04 mol/L or more; and the viscosity of a liquid obtained by evaporating 15% by mass of the ink is less than 3.5 mPa·s at 25° C.

Abstract: An ink jet ink including a self-dispersible pigment, a salt, a polyoxyethylene alkyl ether and a water-soluble organic solvent. The self-dispersible pigment is a pigment to a surface of a particle of which a functional group containing at least a phosphonic acid group is bonded, the introduced amount of the functional group bonded to the self-dispersible pigment is 0.10 to 0.33 mmol/g. The salt is constituted by combining a specific cation with a specific anion. The value (Concentration of anion)×(Valence number of anion) of the salt in the ink is 0.005 to 0.06 mol/L. The water-soluble organic solvent includes glycerol, the content of which in the ink is 35% to 78% by mass based on the total content of the water-soluble organic solvent in the ink.

Abstract: A reaction liquid destabilizing the dissolved state or dispersed state of a coloring material by being in contact with an ink containing the coloring material on a recording medium, wherein the reaction liquid contains at least calcium ions, glycerin and polyethylene glycols, and wherein the content and ratio of these components are specified.

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: The invention provides provide an ink jet ink exhibiting such an excellent ejection property that when an ink containing a polymer capable of improving the scratch resistance of a recorded article is used, the deviation of the ink-droplet impact point on a recording medium is prevented. The ink jet ink contains a polymer and a surfactant, wherein the acid value of the polymer is from 100 mg KOH/g or more to 220 mg KOH/g or less, the weight-average molecular weight of the polymer is from 3,000 or more to 10,000 or less, and the surfactant has a structure represented by the following formula (1) wherein n is a numerical value of from 3 or more to 27 or less, and m is a numerical value of from 16 or more to 31 or less.

Abstract: A reaction liquid destabilizing the dissolved state or dispersed state of a coloring material by being in contact with an ink containing the coloring material on a recording medium, wherein the reaction liquid contains at least calcium ions, glycerin and polyethylene glycols, and wherein the content and ratio of these components are specified.

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.