Ink and processing liquid set, image forming method, and image forming device

Patent metadata

Field	Value
Publication number	US-11040561-B2
Application number	US-201916351588-A
Country	US
Kind code	B2
Filing date	Mar 13, 2019
Priority date	Mar 15, 2018
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

An ink and processing liquid set contains a processing liquid to be applied to a recording medium, the processing liquid including a multivalent metal salt and an ink to be applied to an area of the recording medium where the processing liquid has been applied, the ink including a urethane resin, a styrene-acrylic resin, and a pigment, wherein the following relations are satisfied: 0.5≤B/C≤0.7, where B represents a static surface tension of the ink and C represents a static surface tension of the processing liquid; and 0.5≤E/D≤0.9, and 35 (mN/m)≤E≤55 (mN/m), where D represents a dynamic surface tension at 15 ms of the processing liquid and E represents a dynamic surface tension at 1500 ms of the processing liquid.

First claim

What is claimed is:

1. An ink and processing liquid set comprising:
a processing liquid to be applied to a recording medium, the processing liquid comprising a multivalent metal salt; and
an ink to be applied to an area of the recording medium where the processing liquid has been applied, the ink comprising a urethane resin, a styrene-acrylic resin, and a pigment,
wherein the following relations are satisfied:
0.5≤B/C≤0.7, where B represents a static surface tension of the ink and C represents a static surface tension of the processing liquid; and
0.5≤E/D≤0.9, and 35 (mN/m) ≤E≤55 (mN/m), where D represents a dynamic surface tension at 15 ms of the processing liquid and E represents a dynamic surface tension at 1500 ms of the processing liquid.

2. The set according to claim 1 , wherein the urethane resin has a volume average particle diameter of from 10 to 30 nm.

3. The set according to claim 1 , wherein the styrene-acrylic resin has a volume average particle diameter of from 40 to 60 nm.

4. The set according to claim 1 , wherein the multivalent metal salt comprises at least one member selected from the group consisting of magnesium salts and calcium salts.

5. The set according to claim 1 , wherein the multivalent metal salt accounts for 10 to 40 percent by mass of the processing liquid.

6. The set according to claim 1 , wherein the urethane resin accounts for 1.0 to 5.0 percent by mass of the ink.

7. The set according to claim 1 , wherein the styrene-acrylic resin accounts for 1.0 to 10.0 percent by mass of the ink.

8. The set according to claim 1 , wherein the ink comprises a surfactant represented by the following Chemical formula 1,
C 6 F 13 —CH 2 CH 2 O(CH 2 CH 2 O) n H  Chemical formula 1

where n represents an integer of from 1 to 40.

9. The set according to claim 1 , wherein the urethane resin has a glass transition temperature Tg of 60 degrees C. or lower.

10. The set according to claim 1 , wherein the following relation is satisfied: 1.5≤A/B≤2, where A represents a dynamic surface tension at 15 ms of the ink.

11. The set according to claim 1 , wherein the following relation is satisfied: 1.5≤Y/X≤4, where X represents an initial viscosity of the processing liquid and Y represents a viscosity of the processing liquid at 10 percent moisture evaporation.

12. The set according to claim 1 , wherein the ink comprises black ink, cyan ink, and yellow ink.

13. An image forming method, comprising:
applying a processing liquid to a recording medium; and
applying ink to an area of the recording medium where the processing liquid has been applied,
wherein the processing liquid comprises a multivalent metal salt and the ink comprises a urethane resin, a styrene-acrylic resin, and a pigment, and
wherein the following relations are satisfied:
0.5≤B/C≤0.7, where B represents a static surface tension of the ink and C represents a static surface tension of the processing liquid; and
0.5≤E/D≤0.9, and 35 (mN/m)≤E≤55 (mN/m), where D represents a dynamic surface tension at 15 ms of the processing liquid and E represents a dynamic surface tension at 1500 ms of the processing liquid.

14. The image forming method according to claim 13 , wherein the urethane resin has a volume average particle diameter of from 10 to 30 nm.

15. The image forming method according to claim 13 , wherein the styrene-acrylic resin has a volume average particle diameter of from 40 to 60 nm.

16. The image forming method according to claim 13 , wherein the multivalent metal salt comprises at least one member selected from the group consisting of magnesium salts and calcium salts.

17. The image forming method according to claim 13 , wherein the multivalent metal salt accounts for 10 to 40 percent by mass of the processing liquid.

18. The image forming method according to claim 13 , wherein the urethane resin accounts for 1.0 to 5.0 percent by mass of the ink.

19. The image forming method according to claim 13 , wherein the styrene-acrylic resin accounts for 1.0 to 10.0 percent by mass of the ink.

20. A image forming device, comprising:
a processing liquid;
an ink;
a processing liquid application device configured to apply the processing liquid to a recording medium; and
an ink application device configured to apply the ink to an area of the recording medium where the processing liquid has been applied,
wherein the processing liquid comprises a multivalent metal salt and the ink comprises a urethane resin, a styrene-acrylic resin, and a pigment, and
wherein the following relations are satisfied:
0.5≤B/C≤0.7, where B represents a static surface tension of the ink and C represents a static surface tension of the processing liquid; and
0.5≤E/D≤0.9, and 35 (mN/m) ≤E≤55 (mN/m), where D represents a dynamic surface tension at 15 ms of the processing liquid and E represents a dynamic surface tension at 1500 ms of the processing liquid.

Assignees

• Tamai Takashi
• Jang Dongsik
• Hanazawa Atsufumi
• Takahashi Satoshi
• Yanagawa Yoshiki
• Maekawa Tsutomu
• Watarai Yukitaka
• Ricoh Co Ltd

Inventors

• Tamai Takashi
• Jang Dongsik
• Hanazawa Atsufumi
• Takahashi Satoshi
• Yanagawa Yoshiki
• Maekawa Tsutomu
• Watarai Yukitaka

Classifications

• C09D11/322

  Pigment inks · CPC title

• B41M5/0023 Primary

  Digital printing methods characterised by the inks used (inks per se C09D11/00) · CPC title

• C09D11/54 Primary

  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 · CPC title

• C09D11/30

  Inkjet printing inks · CPC title

• C09D11/102

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