Abstract: Provided is a set of an ink and a print medium, the set including an ink and a print medium, wherein the ink includes at least one organic solvent, polyurethane resin particles, a colorant, and water, wherein the at least one organic solvent includes a compound having a saturated vapor pressure at 100° C. of 65 mmHg or greater but 400 mmHg or less, and wherein a sensor output at a critical image peeling point, measured by a microscratching method, of a solid image formed on the print medium in a manner that the ink is attached in an amount of 0.96 mg/cm2 is 600 or greater.

Abstract: Ink includes a coloring material, an organic solvent, and water, wherein the ink satisfies the following requisites: I. the organic solvent includes an organic solvent X having a solubility parameter (SP value) of 8.9-12.0, II. the organic solvent includes glycol ether compound (compound Z) having a vapor pressure of 50 mmHg or greater at 100 degrees C., and III. a mass ratio of the organic solvent X to the glycol ether compound is 1:1-8:1.

Abstract: Provided is an ink containing a wax, a plurality of organic solvents, and water, wherein the plurality of organic solvents include a compound having a solubility parameter of 9 or greater but 11 or less and a compound having a saturated vapor pressure at 100° C. of 20 mmHg or greater but 400 mmHg or less.

Abstract: An ink for inkjet recording contains water, an organic solvent, a pigment, and a compound represented by the following Chemical formula 1: In Chemical formula 1, M+'s each, independently represent protons, cations of alkali metals, ammonium ions, or organic ammonium ions.

Abstract: A copolymer contains a structure unit represented by Chemical formula 1 and a structure unit represented by Chemical formula 2, where R represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a cation, L1 and L2 each, independently represent alkylene groups having 2 to 18 carbon atoms.

Abstract: A copolymer includes structural units having the following formulae (1) and (2): wherein R represents a hydrogen atom or a methyl group; X represents a hydrogen atom or a cationic ion; and each of L1 and L2 independently represents an alkylene group having 2 to 18 carbon atoms.

Abstract: A copolymer includes the structure unit represented by the following Chemical formula 1 and the structure unit represented by the following Chemical formula 2, where R1 and R2 each, independently represent hydrogen atoms or methyl groups, and n represents a value in the range of from 1 to 90, where R3 represents a hydrogen atom or a methyl group and L represents an alkylene group having 2 to 18 carbon atoms.

Abstract: A copolymer includes structural units having the following formulae (1) and (2): wherein each of R1 and R2 independently represents a hydrogen atom or a methyl group; X represents a hydrogen atom or a cationic ion; and L represents a single bond or —(CH2)n—O—, the oxygen atom of which is bonded with the biphenyl; and n represents an integer of from 2 to 18.

Abstract: An ink composition contains a pigment; a copolymer containing a phosphoric acid group or phosphonic acid group; a hydrosoluble solvent; and water, wherein the pigment is represented by the following chemical formula 1 and satisfies the following relation 1: Y<X<0.8, where X represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 5.5° to 6.0° and Y represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 26.5° to 27.5° to a CuK? X-ray having a wavelength of 1.541 ?. where R each, independently represents monovalent groups selected from hydrogen atoms, methyl groups, or chlorine atoms.

Abstract: An ink includes water, a pigment, and a copolymer, wherein the copolymer contains a structure unit represented by the following Chemical formula 1, where R1 represents a hydrogen atom or a methyl group, M1+ and M2+ each, independently represent monovalent cations, n and m each, independently represent 0 or integers of from 1 to 6 excluding a case where both are 0 and a structure unit represented by the following Chemical formula 2, where R2 represents a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 18 carbon atoms.

Abstract: An ink includes water, a pigment, and a copolymer, wherein the copolymer contains a structure unit represented by the following Chemical formula 1, where R1 represents a hydrogen atom or a methyl group, M1+ and M2+ each, independently represent monovalent cations, n and m each, independently represent 0 or integers of from 1 to 6 excluding a case where both are 0 and a structure unit represented by the following Chemical formula 2, where R2 represents a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 18 carbon atoms.

Abstract: An ink for inkjet recording includes water; a hydrosoluble solvent; a pigment; and a copolymer including a phosphonic acid group. The copolymer including a phosphonic acid group includes structural units having the following formulae (1) and (2): wherein R1 represents a hydrogen atom or a methyl group; and M represents a hydrogen atom, an alkali metal or an organic ammonium; and wherein R2 represents a hydrogen atom or a methyl group; R3 represents an alkyl group having 1 to 4 carbon atoms; and each of n and m represents 0 or an integer of from 1 to 30, provided n+m is from 2 to 30.

Abstract: A copolymer includes structural units having the following formulae (1) and (2): wherein each of R1 and R2 independently represents a hydrogen atom or a methyl group; X represents a hydrogen atom or a cationic ion; and L represents a single bond or —(CH2)n—O—, the oxygen atom of which is bonded with the biphenyl; and n represents an integer of from 2 to 18.

Abstract: An ink composition contains a pigment; a copolymer comprising a phosphoric acid group or phosphonic acid group; a hydrosoluble solvent; and water, wherein the pigment is represented by the following chemical formula 1 and satisfies the following relation 1: Y/X?0.20??Relation 1 where X represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 26.5° to 27.5° and Y represents a peak intensity at a Bragg (2?±0.2°) angle in a range of 2? of from 11.0° to 11.5° to a CuK? X-ray having a wavelength of 1.541 ?.

Abstract: A copolymer includes structural units having the following formulae (1) and (2): wherein R represents a hydrogen atom or a methyl group; X represents a hydrogen atom or a cationic ion; and each of L1 and L2 independently represents an alkylene group having 2 to 18 carbon atoms.

Abstract: Inkjet ink contains a pigment, a hydrosoluble solvent, and water, wherein the pigment is represented by the following chemical formula 1 and has a CuK? X-ray diffraction spectrum having a wavelength of 1.541 ? such that no main peak is observed at a Bragg (2?±0.2°) angle in a range of 2? of from 28.0° to 29.0°, wherein R represents a hydrogen atom, a methyl group, or a chlorine atom.

Abstract: A copolymer contains a structure unit represented by Chemical formula 1 and a structure unit represented by Chemical formula 2, where R represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a cation, L1 and L2 each, independently represent alkylene groups having 2 to 18 carbon atoms.

Abstract: A copolymer includes a structure unit represented by Chemical Formula I; and a structure unit represented by Chemical Formula II, where R1 and R2 each, independently represent hydrogen atoms or methyl groups, X represents a hydrogen atom or a cation, and L represents an alkylene group having 2 to 18 carbon atoms.

Abstract: An ink for inkjet recording, which is used for recording on a paper having a concentration of an eluted Ca ion of from 1.0×10?4 to 5.0×10?4 g/g when dipped in pure water. The ink includes at least a pigment, a pigment dispersant, a water-soluble organic solvent and water. The pigment dispersant is a copolymer synthesized using at least (1) unsaturated ethylene monomer having a phosphoric acid group or a phosphonic acid group and (2) unsaturated ethylene monomer having an alkyl group having 12 to 22 carbon atoms.

Abstract: An inkjet recording ink, including: water; a water-soluble organic solvent; a pigment; and a phosphate group-containing copolymer, wherein the phosphate group-containing copolymer contains a structural unit represented by the following General Formula (1) and a structural unit represented by the following General Formula (2): where R1 denotes a hydrogen atom or a methyl group; M+ denotes an alkali metal ion, an organic amine ion, or a hydrogen ion; half or more of M+ in the copolymer is the alkali metal ion or the organic amine ion, the remainder of M+ is the hydrogen ion; n and m each denote an integer of 0 to 6, provided that both of n and m are not 0; and a block of (C2H4O) and a block of (C3H6O) may be exchanged with each other, where R2 denotes a hydrogen atom or a methyl group.