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US-12624237-B2 - Ink composition, ink set, and image forming method

US12624237B2US 12624237 B2US12624237 B2US 12624237B2US-12624237-B2

Abstract

An ink composition includes a resin-coated pigment in which at least a part of pigments is coated with a cross-linked resin, a betaine compound (1) represented by Formula (1), and water. R 1 represents an alkyl group having 6 to 20 carbon atoms, R 2 and R 3 each independently represent a chain hydrocarbon group having 1 to 3 carbon atoms, L 1 represents a single bond or a divalent linking group, L 2 represents a divalent linking group, and A-represents a —SO 3 − group or a —COO − group.

Inventors

  • Fumiya SHIRAKI

Assignees

  • FUJIFILM CORPORATION

Dates

Publication Date
20260512
Application Date
20210809
Priority Date
20190305

Claims (9)

  1. 1 . An ink composition comprising: (a) cross-linked resin-coated pigment particles each having a volume average particle diameter, comprising: pigment particles each having a volume average particle diameter; and a cross-linked resin, coated on at least a part of each of the pigment particles; (b) a betaine compound (1) represented by Formula (1); and (c) water, in Formula (1), R 1 represents an alkyl group having 6 to 20 carbon atoms, R 2 and R 3 each independently represent a chain hydrocarbon group having 1 to 5 carbon atoms, L 1 represents a single bond or a divalent linking group, L 2 represents a divalent linking group, and A represents a —SO 3 − group.
  2. 2 . The ink composition according to claim 1 , wherein a molecular weight of the betaine compound (1) is 1000 or less.
  3. 3 . The ink composition according to claim 1 , further comprising: an organic solvent A which is a compound represented by Formula (A1) or Formula (A2), in Formula (A1), R A11 represents a chain hydrocarbon group having 4 to 9 carbon atoms or an aryl group having 6 to 10 carbon atoms, R A12 represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3, and in Formula (A2), R A21 represents a chain hydrocarbon group having 4 to 9 carbon atoms or an aryl group having 6 to 10 carbon atoms.
  4. 4 . The ink composition according to claim 3 , wherein a ratio of a mass content of the organic solvent A to a mass content of the betaine compound (1) is 0.5 to 100.
  5. 5 . The ink composition according to claim 1 , further comprising: (d) a resin particle.
  6. 6 . The ink composition according to claim 5 , wherein the resin particle includes a resin particle P consisting of a resin including a structural unit p-1 represented by Formula (p-1), in Formula (p-1), R 31 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, X 1 represents a divalent linking group, Y 1 represents an anionic group, a main chain of Formula (p-1) has a tetravalent carbon that is directly connected to X 1 , and among atoms in X 1 and Y 1 , an atom that is farthest from a main chain of Formula (p-1) is within a range of a 4th atom to a 27th atom away from the tetravalent carbon atom.
  7. 7 . The ink composition according to claim 6 , wherein a proportion of the structural unit p-1 in the resin including the structural unit p-1 is 1% by mass to 20% by mass.
  8. 8 . An ink set comprising: two or more kinds of inks, wherein at least one of the two or more kinds of inks is the ink composition according to claim 1 .
  9. 9 . An image forming method comprising: applying a first ink, which is the ink composition according to claim 1 , to a recording medium; and applying a second ink, which contains a coloring material and water and has a hue different from a hue of the first ink, to the first ink applied to the recording medium.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of PCT International Application No. PCT/JP2020/004026 filed on Feb. 4, 2020, which claims priority under 35 U.S.C § 119(a) to Japanese Patent Application No. 2019-039672 filed on Mar. 5, 2019. Each of the above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to an ink composition, an ink set, and an image forming method. 2. Description of the Related Art In the related art, ink compositions containing an amphoteric surfactant have been known. For example, JP2014-111374A discloses, as an ink jet recording method capable of printing an image without color bleeding regardless of absorbency of a recording medium, a recording method using an ink set combined with an aqueous ink composition composed of at least a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water, and a reaction solution including a reactant which causes aggregate in a case of being in contact with the aqueous ink composition and a cationic resin emulsion, in which the ink composition further contains an anionic or amphoteric surfactant. In addition, JP2002-155225A discloses, as an aqueous pigment ink composition set capable of preventing color bleeding or the like even at a boundary between high-lightness colors and low-lightness colors, an ink set consisting of two or more aqueous ink compositions including a dispersed pigment and a surfactant, in which (1) the ink composition having the lowest lightness has a higher surface tension than those of other ink compositions, (2) the ink composition having the highest lightness has a lower surface tension than those of other ink compositions, and the dispersed pigment contained in the ink composition having the lowest lightness and the dispersed pigment contained in the ink composition (3a) having the highest lightness are both anionic dispersed pigments or (3b) both cationic dispersed pigments, in a case where a condition (3a) is satisfied, (3a-i) the ink composition having the lowest lightness contains an anionic surfactant, and the ink composition having the highest lightness contains an amphoteric surfactant, or (3a-ii) the ink composition having the lowest lightness contains an amphoteric surfactant, and the ink composition having the highest lightness contains an anionic surfactant, and in a case where a condition (3b) is satisfied, (3b-i) the ink composition having the lowest lightness contains a cationic surfactant, and the ink composition having the highest lightness contains an amphoteric surfactant, or (3b-ii) the ink composition having the lowest lightness contains an amphoteric surfactant, and the ink composition having the highest lightness contains a cationic surfactant. In addition, JP2003-201429A discloses, as a pigment ink for ink jet recording, which has excellent jetting stability and storage stability and can give a good recorded image even in a case of being printed on plain paper at high speed using an ink jet recording method, an ink for ink jet recording containing a polymer emulsion in which polymer fine particles contain a water-insoluble or sparingly soluble coloring material, in which the ink for ink jet recording contains at least one wetting agent (first type of hydroxy compound) selected from glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol. 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylolpropane, or trimethylolethane; contains at least a polyol (second type of hydroxy compound) having 8 to 11 carbon atoms or glycol ether, an amphoteric surfactant, a water-soluble organic solvent, and water; and has an ink viscosity of 5 mPa·sec or more at 25° C. In addition, JP2006-241279A discloses, as an ink for ink jet having excellent high-temperature storage stability, an ink for ink jet containing at least a pigment, a water-soluble solvent, at least two types of surfactants, and water, in which (I) at least one type of a nonionic surfactant and at least one of an anionic surfactant and/or an amphoteric surfactant are further contained as the surfactants, (II) the nonionic surfactant has a weight-average molecular weight of 1000 or less and an SP value of 9.2 to 13, and the total number of carbon atoms and oxygen atoms in a unit constituting a hydrophilic group portion is 10 or more in the nonionic surfactant, and (III) the at least one of an anionic surfactant and/or an amphoteric surfactant has a weight-average molecular weight of 175 to 1500. In addition, JP2006-274128A discloses, as an aqueous ink composition suitable for an ink for ink jet recording, which has high storage stability and jetting stability, has high image density with less bleeding, shading unevenness, and strike-through on plain paper, recycled paper, or the like, and has excellent glossiness without blee