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EP-4005798-B1 - INK FOR IMPERMEABLE SUBSTRATE AND IMAGE RECORDING METHOD

EP4005798B1EP 4005798 B1EP4005798 B1EP 4005798B1EP-4005798-B1

Inventors

  • SHIROKANE, Kenji
  • SATO, Ayato

Dates

Publication Date
20260506
Application Date
20200603

Claims (12)

  1. An ink for an impermeable base material, comprising: an aqueous medium, which may be used alone or in combination of two or more kinds thereof, wherein the aqueous medium is selected from water and a water-soluble organic solvent; and resin particles, wherein a resin of the resin particles has a glass transition temperature, measured in conformity with the method described in JIS K 7121: 1987 or JIS K 6240: 2011 using differential scanning calorimetry, of -40°C or higher and 85°C or lower, the resin has at least one selected from the group consisting of the following structural unit (1), the following structural unit (2), and the following structural unit (3) and at least one of an acid group or a salt of the acid group, an acid value of the resin, which is a total number of millimoles of the acid group and the salt of the acid group per 1 g of the resin, is 0.10 mmol/g or greater and 2.65 mmol/g or less, a content of a structural unit derived from an alkyl (meth)acrylate containing a chain alkyl group having 2 or more carbon atoms in the resin is 5% by mass or less with respect to an entirety of the resin, and a proportion of a water-soluble organic solvent having a boiling point of 250°C or higher in the aqueous medium is 3% by mass or less, in the structural unit (1) to the structural unit (3), R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, in the structural unit (1), A 2 represents -NH- or -N(L 4 -Y 4 )-, L 2 represents a divalent group which is one selected from the first group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -O-, -NH-, - N(L 4 -Y 4 )-, and -C(=O)-, a divalent group which is obtained by combining two or more selected from the first group, or a single bond, Y 2 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a halogen atom, -OH, -OR 3 , -NH 2 , -NR 3 H, -NR 3 R 4 , or -C(=O)R 3 , and two of A 2 , L 2 , and Y 2 may be linked to each other to form a ring, in the structural unit (2), L 3 represents a divalent group which is one selected from the first group or a divalent group which is obtained by combining two or more selected from the first group, Y 3 represents a halogen atom, -OH, -OR 3 , -NH 2 , -NR 3 H, -NR 3 R 4 , or -C(=O)R 3 , and L 3 and Y 3 may be linked to each other to form a ring, in the structural unit (1) and the structural unit (2), L 4 represents a divalent group which is one selected from the second group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -O-, -NH-, and -C(=O)-, a divalent group which is obtained by combining two or more selected from the second group, or a single bond, Y 4 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a halogen atom, -OH, -OR 3 , -NH 2 , -NR 3 H, -NR 3 R 4 , or -C(=O)R 3 , and R 3 and R 4 each independently represent an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, provided that R 3 and R 4 in Y 3 of the structural unit (2) each independently represent an alkyl group, an alkenyl group, or an alkynyl group, in the structural unit (1) and the structural unit (2), L 4 and Y 4 in -N(L 4 -Y 4 )- may be linked to each other to form a ring, and R 3 and R 4 in -NR 3 R 4 may be linked to each other to form a ring.
  2. The ink for an impermeable base material according to claim 1, wherein the resin has a structural unit containing at least one of the acid group or the salt of the acid group, and the structural unit containing at least one of the acid group or the salt of the acid group is at least one selected from the group consisting of the following structural unit (4), the following structural unit (5), and the following structural unit (6), in the structural unit (4) to the structural unit (6), R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, L A represents a divalent group which is one selected from the third group consisting of an alkylene group having 1 to 30 carbon atoms, an arylene group having 6 to 10 carbon atoms, -O-, -NH-, -S-, -C(=O)-, and -CH(-OH)-, a divalent group which is obtained by combining two or more selected from the third group, or a single bond, A represents an acid group or a salt of the acid group, and n represents an integer of 1 to 5.
  3. The ink for an impermeable base material according to claim 1 or 2, wherein the resin further has at least one selected from the group consisting of the following structural unit (A), the following structural unit (B), the following structural unit (C), the following structural unit (D), the following structural unit (E), and the following structural unit (F), in the structural unit (A) to the structural unit (F), R 5 represents a hydrogen atom or a methyl group, R 6 represents an alkyl group, an alkenyl group, or an alkynyl group, R 7 represents an alkyl group having 2 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, or an alkynyl group having 2 to 22 carbon atoms, m represents an integer of 0 to 5, n represents an integer of 0 to 11, L 5 represents a divalent group which is one selected from the fourth group consisting of an alkylene group having 1 to 18 carbon atoms, an arylene group having 6 to 18 carbon atoms, -O-, -NH-, -S-, and -C(=O)-, a divalent group which is obtained by combining two or more selected from the fourth group, or a single bond.
  4. The ink for an impermeable base material according to claim 3, wherein a total content of the structural unit (1), the structural unit (2), the structural unit (3), the structural unit (A), the structural unit (B), the structural unit (C), the structural unit (D), the structural unit (E), and the structural unit (F) is 70% by mass or greater with respect to an entirety of the resin.
  5. The ink for an impermeable base material according to claim 3 or 4, wherein the resin has at least one selected from the group consisting of the structural unit (C), the structural unit (D), the structural unit (E), and the structural unit (F).
  6. The ink for an impermeable base material according to any one of claims 1 to 5, wherein the resin has a glass transition temperature of -20°C or higher and 55°C or lower.
  7. The ink for an impermeable base material according to any one of claims 1 to 6, wherein a total content of the structural unit (1), the structural unit (2), and the structural unit (3) is 5% by mass or greater with respect to an entirety of the resin.
  8. The ink for an impermeable base material according to any one of claims 1 to 7, wherein the resin has at least one selected from the group consisting of the structural unit (1) and the structural unit (2).
  9. The ink for an impermeable base material according to any one of claims 1 to 8, wherein the resin has the structural unit (2), and Y 3 in the structural unit (2) represents -OH, -NH 2 , -NR 3 H, or -NR 3 R 4 .
  10. The ink for an impermeable base material according to any one of claims 1 to 9, wherein the ink is an inkjet ink.
  11. The ink for an impermeable base material according to any one of claims 1 to 10, further comprising: a colorant.
  12. An image recording method comprising: a step of applying the ink for an impermeable base material according to any one of claims 1 to 11 onto an impermeable base material.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to an ink for an impermeable base material, and an image recording method. 2. Description of the Related Art In the related art, various examinations have been performed on inks used for image recording. For example, JP2019-59855A discloses, as an aqueous ink composition for ink jet recording which exhibits excellent preservation stability and filterability, has excellent jettability and drying properties in a case of being applied to an ink jet recording method, and is capable of forming a high-quality image with excellent rub resistance, an aqueous ink composition for ink jet recording, containing water, an organic solvent, and resin fine particles, in which the organic solvent contains a hydrophobic organic solvent having a ClogP value of 0 to 3.5, the content of the hydrophobic organic solvent in the aqueous ink composition for ink jet recording is in a range of 0.5% to 10% by mass, and the resin fine particles have a structural unit (I) and a structural unit (II) respectively represented by specific formulae. JP2016-69583A discloses, as an aqueous ink composition which is capable of forming an image excellent in rub resistance, scratch resistance, blocking resistance and also exhibits satisfactory jetting stability in a case of being used as an ink for ink jet recording, an aqueous ink composition containing at least an aqueous medium and resin fine particles, in which the resin of the resin fine particles has a structural unit (a), a structural unit (b), and a structural unit (c). Here, the structural unit (a) is a specific structural unit containing an amino group in a side chain, the structural unit (b) is a specific structural unit containing an acidic group, and the structural unit (c) is a specific structural unit containing an alkyl group having 12 to 22 carbon atoms, a specific structural unit having a fluoroethylene structure in a side chain, or a specific structural unit having a polysiloxane structure in a side chain. WO2016/52119A discloses, as an aqueous ink composition which is capable of forming an image excellent in rub resistance, scratch resistance, and blocking resistance and also exhibits satisfactory jetting stability in a case of being used as an ink for ink jet recording, an aqueous ink composition containing at least an aqueous medium and resin fine particles formed of a resin, in which the resin has the following structural units (a), (b), and (c). Here, the structural unit (a) is a structural unit having an amine structure in a side chain, the structural unit (b) is a structural unit containing an acidic group, and the structural unit (c) is a structural unit containing a group selected from a monovalent group represented by -L-OH, a divalent group represented by -CONRC-, or a divalent group represented by -SO2NRC-. L represents an alkylene group having 1 to 10 carbon atoms, and RC represents a hydrogen atom or an alkyl group. JP2019-26845A discloses, as an aqueous ink for ink jet recording with excellent bleed resistance, an aqueous ink for ink jet recording, containing a pigment, a polymer, a water-soluble organic solvent, and water, in which the polymer is a random copolymer or a block copolymer having (a) structural unit derived from one or more monomers selected from acrylic acid and methacrylic acid and (b) structural unit derived from a hydrophobic vinyl monomer, which is a carboxy group-containing polymer having an acid value of 150 to 300 mgKOH/g, the water-soluble organic solvent contains one or more compounds selected from polyhydric alcohol and polyhydric alcohol alkyl ether, the total content of the polyhydric alcohol and the polyhydric alcohol alkyl ether in the ink is 18% by mass or greater, and the organic solvent contains a compound releasing formaldehyde. JP2018-177828A discloses, as a resin dispersion for an aqueous inkjet ink which is capable of achieving both ink physical properties such as preservation stability and jettability and coating film properties such as gloss, abrasion resistance, water resistance, and solvent resistance, a resin dispersion for an aqueous inkjet ink, containing an aqueous medium and resin particles serving as an emulsion polymerization product of a monomer mixture that contains greater than 58.5% by mass and less than 96.7% by mass of a styrene monomer, greater than 3% by mass and less than 9.6% by mass of a (meth)acrylic acid alkyl ester monomer containing an alkyl group having 4 to 12 carbon atoms, 0.1% to 10% by mass of a carboxyl group-containing monomer, 0.1% to 10% by mass of an alkoxysilyl group-containing monomer, and 0.1% to 10% by mass of a surfactant monomer. JP2018-177828A also discloses an aqueous inkjet ink formed of the above-described resin dispersion for an aqueous inkjet ink. US 2012/033011 A1 teaches an inkjet ink comprising at least water, a pigment, a resin, a water-soluble organic solvent, and a surfactant, wherein the resi