Ink set and image forming method

• US 10,174,218 B2
• Filed: 08/22/2017
• Issued: 01/08/2019
• Est. Priority Date: 02/27/2015
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Shimono, Katsuhiro, Arai, Takuya
• Primary Examiner(s): Uhlenhake, Jason S
• Application Number:
  US15/682,565
• Publication Number:
  US 20170349774A1
• Time in Patent Office: 504 Days
• CPC Class Codes: B41J 2/01 Ink jet
• CPC Class Codes: B41M 5/00 Duplicating or marking methods; Sheet materials for use therein by using light-sensitive materials G03; electrography, magnetography G03G ; repeatedly usable boards or tablets for writing or drawing B43L1/00
• CPC Class Codes: B41M 5/0017 Application of ink-fixing material, e.g. mordant, precipitating agent, on the substrate prior to printing, e.g. by ink-jet printing, coating or spraying
• CPC Class Codes: C09D 11/10 based on artificial resins
• CPC Class Codes: C09D 11/107 from unsaturated acids or derivatives thereof
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing
• CPC Class Codes: C09D 11/54 Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink

Abstract

Provided is an ink set including an ink composition which contains a colorant and water; and a treatment liquid which contains water-insoluble resin particles in which the content of a carboxy group or a salt of the carboxy group is in a range of 1.0 mmol to 7.0 mmol per 1 g of the water-insoluble resin particles, a compound that causes the colorant in the ink composition to aggregate, and water.

Claims

1. An ink set comprising:

an ink composition which contains a colorant and water; and

a treatment liquid which contains water-insoluble resin particles in which a content of a carboxy group or a salt of the carboxy group is in a range of 1.0 mmol to 7.0 mmol per 1 g of the water-insoluble resin particles, a compound that causes the colorant in the ink composition to aggregate, and water,

wherein the water-insoluble resin particles include at least one constitutional unit selected from a constitutional unit represented by Formula 1 or 2, and

the total content of the constitutional unit represented by Formula 1 and the constitutional unit represented by Formula 2 is in a range of 10% by mass to 50% by mass with respect to the total mass of the water-insoluble resin particles,

2. The ink set according to claim 1,

wherein the water-insoluble resin particles further include a sulfo group or a salt of the sulfo group.

3. The ink set according to claim 2,

wherein the water-insoluble resin particles include at least one sulfo group or salt of a sulfo group in a terminal of a water-insoluble resin.

4. The ink set according to claim 2,

wherein the content of the sulfo group or the salt of the sulfo group in the water-insoluble resin particles is in a range of 0.1 mmol to 1.2 mmol per 1 g of the water-insoluble resin particles.

5. The ink set according to claim 2,

wherein a ratio of the total amount of the sulfo group or the salt of the sulfo group to the total amount of the carboxy group or the salt of the carboxy group, per 1 g of the water-insoluble resin particles, is in a range of 0.08 to 2.0 on a molar basis.

6. The ink set according to claim 1,

wherein the water-insoluble resin particles include a constitutional unit represented by Formula 3, and

the content of the constitutional unit represented by Formula 3 is in a range of 5% by mass to 25% by mass with respect to the total mass of the water-insoluble resin particles,

7. The ink set according to claim 1,

wherein the water-insoluble resin particles include a constitutional unit containing a hydrophobic group, and

the content of the constitutional unit containing a hydrophobic group is in a range of 5% by mass to 40% by mass with respect to the total mass of the water-insoluble resin particles.

8. The ink set according to claim 7,

wherein a ratio of the content of the constitutional unit containing a hydrophobic group to the content of a constitutional unit derived from a monomer containing a carboxy group or a salt of the carboxy group is in a range of 0.2 to 1.4 on a mass basis, in the water-insoluble resin particles.

9. The ink set according to claim 7,

wherein the constitutional unit containing a hydrophobic group is at least one constitutional unit selected from constitutional units represented by Formulae A to F,

10. The ink set according to claim 9,

wherein the content of the water-insoluble resin particles is in a range of 0.5% by mass to 20% by mass with respect to the total mass of the treatment liquid, and a volume average particle diameter of the water-insoluble resin particles is 1 μ

m or less.

11. The ink set according to claim 9,

wherein a glass transition temperature of the water-insoluble resin particles is in a range of 100°

C. to 250°

C., and a weight-average molecular weight of the water-insoluble resin particles is in a range of 5.0×

10³ to 5.00×

10⁴.

12. The ink set according to claim 1,

wherein the content of the water-insoluble resin particles is in a range of 0.5% by mass to 20% by mass with respect to the total mass of the treatment liquid.

13. The ink set according to claim 1,

wherein a volume average particle diameter of the water-insoluble resin particles is 1 μ

m or less.

14. The ink set according to claim 1,

wherein a glass transition temperature of the water-insoluble resin particles is in a range of 100°

C. to 250°

C.

15. The ink set according to claim 14,

wherein a weight-average molecular weight of the water-insoluble resin particles is in a range of 5.0×

10³ to 5.00×

10⁴.

16. The ink set according to claim 1,

wherein the compound that causes the colorant in the ink composition to aggregate is an organic acidic compound.

17. The ink set according to claim 16,

wherein a ratio of the content of the water-insoluble resin particles to the content of the compound that causes the colorant in the ink composition to aggregate is in a range of 0.01 to 2.0 on a mass basis.

18. An image forming method comprising:

a pre-treatment step of applying the treatment liquid of the ink set according to claim 1 to at least one surface of a substrate having a contact angle of 70°

or greater when 3 seconds have elapsed from application of water droplets to the surface; and

an image forming step of forming an image by ejecting the ink composition of the ink set according to claim 1 to the surface of the substrate to which the treatment liquid is applied using an inkjet method.

19. The image forming method according to claim 18,

wherein the substrate is a paper substrate having a coating layer.