Abstract: An ink set according to the invention includes a yellow ink, a magenta ink, and a cyan ink, in which each of the inks contains a coloring agent which includes water and a pigment, the coloring agent of the magenta ink and the cyan ink is a first coloring agent which has a phosphorus-containing group on a surface of the pigment, the coloring agent of the yellow ink is a second coloring agent where a surface of the pigment is covered by a styrene-acryl resin, and each of the inks contains 50 mass % or more to 60 mass % or less of water with respect to the total mass of the ink.

Abstract: An ink jet recording aqueous pigment ink contains a self-dispersing pigment, a quaternary amino acid, a non-polymeric, nonionic material having a melting point of 40° C. or more, and at least one of trialkylamine and trialkanolamine. The content of the non-polymeric, nonionic material is 3% to 15% by mass relative to the total mass of the ink jet recording aqueous pigment ink.

Abstract: An ink jet recording apparatus including an ink jet head for ejecting a water-based ink from a nozzle onto a recording medium, wherein the water-based ink contains a fatty acid and a fatty acid potassium or sodium salt with which the fatty acid is emulsified and dispersed in water.

Abstract: An ink jet recording apparatus including an ink jet head for ejecting a water-based ink while moving at a speed of 0.5 m/s or more relative to a recording medium, wherein the water-based ink contains a fatty acid and a volatile alcohol, the volatile alcohol being used to emulsify the fatty acid and disperse the fatty acid in water and having a higher vapor pressure than water at 20° C.

Abstract: An ink jet recording device is provided which includes an ink jet head which has a nozzle surface where a plurality of nozzle opening ends are arranged and which ejects water-based ink from the nozzles to a recording medium and a wiping device that executes a wiping operation where the nozzle surface and a wiping member are brought into contact and the nozzle surface is wiped, where oleic acid and a dispersant for dispersing the oleic acid into water by emulsifying the oleic acid are added to the water-based ink.

Abstract: An ink set includes at least a cyan ink composition containing a self-dispersible pigment, a magenta ink composition containing a self-dispersible pigment, and a yellow ink composition containing a pigment coated with a water-insoluble polymer.

Abstract: An ink jet recording apparatus in which an image is recorded by ejecting a pigment ink from an ink jet head on a recording surface of a recording medium, the apparatus including: a recording medium transporting unit which transports the recording medium, and a recording medium discharging unit which discharges the recording medium, wherein the recording medium discharging unit includes a discharging roller installed on the opposite side to the recording surface of the recording medium and a cylinder-shaped driven roller installed on the recording surface side of the recording medium so as to face the discharging roller, the driven roller has an electrical resistivity smaller than 108 ?cm, and is grounded, and the pigment ink has an electrical conductivity of equal to or more than 0.5 mS/m.

Abstract: An ink jet recording aqueous pigment ink contains a self-dispersing pigment, a quaternary amino acid, a non-polymeric, nonionic material having a melting point of 40° C. or more, and at least one of trialkylamine and trialkanolamine. The content of the non-polymeric, nonionic material is 3% to 15% by mass relative to the total mass of the ink jet recording aqueous pigment ink.

Abstract: An ink composition includes at least a pigment, a polyhydric alcohol monoalkyl ether having a vapor pressure of 0.1 mmHg or less at 20° C. and/or a nitrogen-containing cyclic compound, a polyhydric alcohol, an unsaturated fatty acid, an alkyl alcohol having 1 to 4 carbon atoms, a surfactant, and 10% to 60% by mass of water. An in jet recording method uses the ink composition, and a recorded matter is produced by the ink jet recording method.

Abstract: An ink jet recording apparatus including an ink jet head for ejecting a water-based ink while moving at a speed of 0.5 m/s or more relative to a recording medium, wherein the water-based ink contains a fatty acid and a volatile alcohol, the volatile alcohol being used to emulsify the fatty acid and disperse the fatty acid in water and having a higher vapor pressure than water at 20° C.

Abstract: An ink jet recording apparatus including an ink jet head for ejecting a water-based ink from a nozzle onto a recording medium, wherein the water-based ink contains a fatty acid and a fatty acid potassium or sodium salt with which the fatty acid is emulsified and dispersed in water.

Abstract: An ink jet recording device is provided which includes an ink jet head which has a nozzle surface where a plurality of nozzle opening ends are arranged and which ejects water-based ink from the nozzles to a recording medium and a wiping device that executes a wiping operation where the nozzle surface and a wiping member are brought into contact and the nozzle surface is wiped, where oleic acid and a dispersant for dispersing the oleic acid into water by emulsifying the oleic acid are added to the water-based ink.

Abstract: An ink set includes at least a cyan ink composition containing a self-dispersible pigment, a magenta ink composition containing a self-dispersible pigment, and a yellow ink composition containing a pigment coated with a water-insoluble polymer.