Aqueous inkjet ink and method for producing printed item

Patent metadata

Field	Value
Publication number	US-11427723-B2
Application number	US-201816077046-A
Country	US
Kind code	B2
Filing date	Apr 17, 2018
Priority date	Apr 21, 2017
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

One embodiment relates to an aqueous inkjet ink containing a pigment (A), a polymer compound (B), a water-soluble organic solvent (C) and a surfactant (D), wherein the water-soluble organic solvent (C) includes ethylene glycol and/or 1,3-propanediol (c1), and a water-soluble organic solvent (c2) having a specific static surface tension, the acid value of the polymer compound (B), the amount of water-soluble organic solvent having a boiling point at 1 atmosphere of 240° C. or higher, and the weight average boiling point at 1 atmosphere for the water-soluble organic solvent (C) are all prescribed values, and the blend amounts of the various components satisfy specific relationships.

First claim

The invention claimed is:

1. An aqueous inkjet ink comprising a pigment (A), a polymer compound (B), a water-soluble organic solvent (C) and a surfactant (D), wherein
an acid value of the polymer compound (B) is from 10 to 100 mgKOH/g,
the water-soluble organic solvent (C) comprises ethylene glycol and/or 1,3-propanediol (c1), and a water-soluble organic solvent (c2) having a static surface tension at 25° C. of 20 to 37 mN/m, and an amount of water-soluble organic solvent having a boiling point at 1 atmosphere of 240° C. or higher is not more than 5% by weight relative to a total weight of the aqueous inkjet ink,
a weight average boiling point at 1 atmosphere for the water-soluble organic solvent (C) is from 180 to 210° C., and
relative to a total weight of the aqueous inkjet ink, if an amount of the pigment (A) is termed WA (% by weight), an amount of the polymer compound (B) is termed WB (% by weight), an amount of the ethylene glycol and/or 1,3-propanediol (c1) is termed WC1 (% by weight), and an amount of the water-soluble organic solvent (c2) having a static surface tension at 25° C. of 20 to 37 mN/m is termed WC2 (% by weight), then WA, WB, WC1 and WC2 satisfy all of formulas (1) to (5) shown below:
3≤ WA≤ 7  (1)

6≤ WA+WB≤ 20  (2)

10≤ WC 1+ WC 2≤40  (3)

0.25≤ WC 1/( WA+WB )≤1.75  (4)

1.5≤ WC 2/ WC 1≤5  (5).

2. The aqueous inkjet ink according to claim 1 , wherein the water-soluble organic solvent (c2) having a static surface tension at 25° C. of 20 to 37 mN/m comprises a 1,2-alkanediol of 3 to 6 carbon atoms.

3. The aqueous inkjet ink according to claim 1 , wherein the ethylene glycol and/or 1,3-propanediol (c1) comprises ethylene glycol.

4. The aqueous inkjet ink according to claim 1 , wherein an amount of the surfactant (D) is from 1 to 5% by weight of a total weight of the aqueous inkjet ink.

5. The aqueous inkjet ink according to claim 1 , wherein the surfactant (D) comprises a siloxane-based surfactant.

6. A method for producing an aqueous inkjet ink printed item, the method having a step of discharging the aqueous inkjet ink according to claim 1 from an inkjet head and adhering the aqueous inkjet ink to a printing substrate, and a step of drying the printing substrate with the adhered aqueous inkjet ink, wherein
a nozzle diameter of the inkjet head is from 15 to 25 μm, and a design resolution of the inkjet head is 600 dpi or higher.

7. The aqueous inkjet ink according to claim 2 , wherein the ethylene glycol and/or 1,3-propanediol (c1) comprises ethylene glycol.

8. The aqueous inkjet ink according to claim 2 , wherein an amount of the surfactant (D) is from 1 to 5% by weight of a total weight of the aqueous inkjet ink.

9. The aqueous inkjet ink according to claim 2 , wherein the surfactant (D) comprises a siloxane-based surfactant.

10. A method for producing an aqueous inkjet ink printed item, the method having a step of discharging the aqueous inkjet ink according to claim 2 from an inkjet head and adhering the aqueous inkjet ink to a printing substrate, and a step of drying the printing substrate with the adhered aqueous inkjet ink, wherein
a nozzle diameter of the inkjet head is from 15 to 25 μm, and a design resolution of the inkjet head is 600 dpi or higher.

Assignees

• Toyo Ink Sc Holdings Co Ltd
• Toyocolor Co Ltd

Inventors

• Suzuki Yoshihito
• Yoda Atsushi
• Sugihara Masahiro
• Jonai Kazuhiro

Classifications

• C08L83/04

  Polysiloxanes · CPC title

• C09D11/38 Primary

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title

• C08K5/053

  Polyhydroxylic alcohols · CPC title

• C09D11/322 Primary

  Pigment inks · CPC title

• C08L25/14

  with unsaturated esters · CPC title