Ink set, image forming method, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-12441902-B2
Application number	US-202318352524-A
Country	US
Kind code	B2
Filing date	Jul 14, 2023
Priority date	Jul 19, 2022
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

An ink set is provided that includes a pretreatment liquid containing a resin (R1), a color ink containing a resin (R2), and a clear ink containing a resin (R3), in which the resin (R1), the resin (R2), and the resin (R3) have an identical type of bonding structure in a repeating unit of a molecule.

First claim

The invention claimed is:

1. An ink set, comprising:
a pretreatment liquid containing a resin (R1);
a color ink containing a resin (R2); and
a clear ink containing a resin (R3),
the resin (R1), the resin (R2), and the resin (R3) having an identical type of bonding structure in a repeating unit of a molecule.

2. The ink set according to claim 1 , wherein the resin (R1), the resin (R2), and the resin (R3) all comprise a urethane resin or an acrylic resin.

3. The ink set according to claim 1 , wherein the pretreatment liquid comprises 1,2-propanediol.

4. The ink set according to claim 1 , wherein the pretreatment liquid contains a polyvalent metal compound, and the polyvalent metal compound includes a calcium salt.

5. The ink set according to claim 1 , wherein a dry film of the clear ink has a glass transition temperature (Tg) of 50° C. or more and less than 0° C.

6. The ink set according to claim 1 , wherein the resin (R3) includes resin particles having a volume average particle diameter of 50 nm or less.

7. The ink set according to claim 1 , wherein the resin (R3) includes:
resin particles A having a glass transition temperature (Tg) of 50° C. or higher; and
resin particles B having a glass transition temperature (Tg) of less than 0° C.

8. The ink set according to claim 7 , wherein a mass ratio (MA:MB) between a mass MA (mg) of the resin particles A and a mass MB (mg) of the resin particles B is from 98:2 to 80:20.

9. The ink set according to claim 7 , wherein the resin particles A comprise a urethane resin.

10. The ink set according to claim 1 , wherein a proportion of the resin (R3) in the clear ink is 10% by mass or more.

11. The ink set according to claim 1 , wherein the clear ink includes a surfactant, and a proportion of the surfactant in the clear ink is 2% by mass or less.

12. An image forming apparatus comprising:
a pretreatment liquid applicator to apply a pretreatment liquid containing a resin (R1) onto an impermeable base material;
a color ink applicator to apply a color ink containing a resin (R2); and
a clear ink applicator to apply a clear ink containing a resin (R3),
the resin (R1), the resin (R2), and the resin (R3) having an identical type of bonding structure in a repeating unit of a molecule.

Assignees

• Masuda Kiminori
• Takahashi Hiroaki
• Kudo Masaki
• Ricoh Co Ltd

Inventors

• Masuda Kiminori
• Takahashi Hiroaki
• Kudo Masaki

Classifications

• C09D11/36

  based on non-aqueous solvents · CPC title

• C09D11/023

  Emulsion inks · CPC title

• C09D11/102

  containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds · CPC title

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title

• C09D11/322

  Pigment inks · CPC title