Abstract: An ink for ink jet recording according to an embodiment is an ink for ink jet recording containing pigment, colloidal silica, amine, and amino acid.

Abstract: An ink set of the present disclosure includes a colored ink jet ink and a decoloring ink. The colored ink jet ink includes a leuco dye, a developer, and a dispersant, and the decoloring ink includes a solvent and water. The solvent includes a specific solvent component that has a Hansen solubility parameter that differs from the Hansen solubility parameter of the developer by an absolute value of less than or equal to 5.3. Preferably, the specific solvent component is a glycol ether or a glycol. Preferably, the leuco dye is a fluoran. Preferably, the developer is a compound containing a phenolic hydroxy group in the molecule.

Abstract: An ink jet ink composition is a water-based ink jet ink composition and includes a vegetable black-derived colorant, a lignosulfonate salt, and an element A which includes at least one selected from the group consisting of Ca, Mg, Mn, Fe, Al, Si, Cr, Ni, Sr, and Ba, and a content of the element A with respect to a total mass of the ink composition is 50 to 1,700 mass ppm.

Abstract: An aqueous ink jet ink composition contains pigment particles, inorganic oxide particles, and resin particles. The content of the inorganic oxide particles is 1.0% to 10.0% relative to the total mass of the ink composition. The ink composition satisfies the following relationship: D50 of the resin particles ?D50 of the inorganic oxide particles ?D50 of the pigment particles, wherein D50 represents the volume median diameter of the corresponding particles.

Abstract: An ink jet ink composition includes water, a phospholipid that forms a fine particle, and a coloring material that is incorporated in the fine particle.

Abstract: An ink jet printing ink composition contains a pigment, colloidal silica, trimethylglycine, and water, and in which a content of the colloidal silica is lower than or equal to a content of the trimethylglycine.

Abstract: An ink jet ink composition includes water, a plant-derived carbonized color material, and a lignin resin.

Abstract: An ink jet ink composition includes a color material having a ligand; an inorganic compound; and a pH adjuster, and the color material forms a complex with the inorganic compound by the ligand.

Abstract: An ink jet ink composition includes: a colorant; silica particles; 1-(2-hydroxyethyl)-2-pyrrolidone; and water, and the silica particles have in a TEM image thereof, a Di (diameter of the maximum inscribed circle)/Dc (diameter of the minimum circumscribed circle) of 0.7 or more.

Abstract: An ink jet ink composition includes a self-dispersible pigment; an alcohol having 4 carbon atoms or less; an asymmetric alkyl ether; and water, a content of the alcohol with respect to a total mass of the ink jet ink composition is 0.5 to 15 percent by mass, and a content of the water with respect to the total mass of the ink jet ink composition is 10 to 40 percent by mass.

Abstract: An ink set including at least one first ink composition and at least one second ink composition, wherein the first ink composition contains a pigment, an inorganic oxide colloid, and water, the second ink composition contains a dye and water, and in the ink set, an arithmetic mean of a conductivity of the at least one first ink composition at 25° C. and a conductivity of the at least one second ink composition at 25° C. is 2.5 mS/cm or less.

Abstract: An aqueous ink jet composition is provided that contains at least one dye composed of at least one of sublimation dyes or at least one of disperse dyes, polyester, and water. The polyester content is higher than or equal to 4 times and lower than or equal to 300 times the dye content. Preferably, the polyester content is 5% by mass or more and 30% by mass or less. Preferably, the dye content is 0.1% by mass or more and 7.5% by mass or less.

Abstract: An ink composition contains pigment particles, inorganic oxide particles, and a lactam solvent. The content of the inorganic oxide particles is 5.0% to 10.0% relative to the total mass of the ink composition. The ink composition satisfies the following relationship: D50 of the pigment particles×0.1?D50 of the inorganic oxide particles?D50 of the pigment particles×1.5, wherein D50 represents the volume median diameter of the corresponding particles.

Abstract: An aqueous ink jet composition includes a pigment, polyester, 1-(hydroxyalkyl)-2-pyrrolidone, an organic amine, and water, wherein the pigment, the polyester, and the 1-(hydroxyalkyl)-2-pyrrolidone have a relationship of expression (1): C?A?B, where A is the content (mass %) of the pigment with respect to the total mass, B is the content (mass %) of the polyester with respect to the total mass, and C is the content (mass %) of the 1-(hydroxyalkyl)-2-pyrrolidone with respect to the total mass.

Abstract: An aqueous ink jet composition includes a dye component composed of at least one of sublimation dyes and disperse dyes, polyester, 1-(hydroxyalkyl)-2-pyrrolidone, and water, wherein the content (mass %) of the polyester is 4.0 times or more and 300.0 times or less the content (mass %) of the dye component.

Abstract: An ink jet ink contains: an inorganic oxide colloid; an amino acid; a first glycol monoether represented by the following formula (1): R11O—(R12O)n1—H (1); a second glycol monoether represented by the following formula (2): R21O—(R22O)n2—H(2); and water. In the ink jet ink described above, in the formula (1), R11 represents an alkyl group having 2 to 10 carbon atoms, R12 represents an alkylene group having 2 to 4 carbon atoms, and n1 represents a repetition number of 1 to 10, and in the formula (2), R21 represents an alkyl group having 1 to 8 carbon atoms, R22 represents an alkylene group having 2 to 4 carbon atoms, the number of carbon atoms of R21 is smaller than the number of carbon atoms of R11, and n2 represents a repetition number of 1 to 10.

Abstract: An ink for ink jet recording according to an embodiment is an ink for ink jet recording containing pigment, colloidal silica, amine, and amino acid.

Abstract: An ink jet ink contains an inorganic oxide colloid; a betaine; 1-(2-hydroxyethyl)-2-pyrrolidone; and water, and in the ink jet ink described above, a content of the betaine is equivalent to or larger than a content of a solid component of the inorganic oxide colloid on a mass basis.

Abstract: An ink jet ink contains a pigment; an inorganic oxide colloid; a betaine; and water, and in the ink jet ink described above, a total concentration (mg/L) of potassium ions and sodium ions in the ink is 500 ppm or less.

Abstract: An ink for ink jet recording according to an embodiment is an ink for ink jet recording containing pigment, colloidal silica, and amino acid.