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