Aqueous ink jet ink composition, ink jet recording method, and method for controlling ink jet recording apparatus
An aqueous ink jet ink composition contains a pigment dispersed with a dispersant resin, resin fine particles, water, and an organic solvent. The aqueous ink jet ink composition does not contain more than 5% by mass of an organic solvent having a normal boiling point of 280° C. or more. Further, a viscosity increase rate of the aqueous ink jet ink composition is within 200% at 20° C. when 20% by mass of the water evaporates, and a difference in the SP values between the dispersant resin and a resin of the resin fine particles is within 2.
1. An ink jet recording method comprising:
discharging an aqueous ink jet ink composition from a pressure chamber of an ink jet head through a nozzle onto a recording medium,
wherein the recording medium is in a heated state when the aqueous ink jet ink composition is applied to the recording medium,
the ink jet head has a step between the pressure chamber and the nozzle, and
the aqueous ink jet ink composition includes:
a pigment dispersed with a dispersant resin;
resin fine particles;
water;
an organic solvent; and
a nitrogen-containing solvent,
wherein a content of an organic solvent having a normal boiling point of 280° C. or more is no more than 5% relative to a total mass of the aqueous ink jet ink composition,
a viscosity increase rate of the aqueous ink jet ink composition is within 200% at 20° C. when 20% by mass of the water evaporates,
a difference in solubility parameter values between the dispersant resin and a resin of the resin fine particles is within 2,
a difference in solubility parameter values between the organic solvent and the dispersant resin or the resin of the resin fine particles is within 2,
a content of the organic solvent in which the difference in the solubility parameter values between the organic solvent and the dispersant resin or the resin of the resin fine particles is within 2 is 20% by mass or less, and
a content of the nitrogen-containing solvent is 5% by mass or more based on the total mass of the aqueous ink jet ink composition.
2. The ink jet recording method according to claim 1 , wherein a number of particles having a particle diameter of 20 μm or more contained in the aqueous ink jet ink composition is 50 particles/ml or less when 20% by mass of the water contained evaporates.
3. The ink jet recording method according to claim 1 , wherein a number of particles having a particle diameter of 20 μm or more contained in the aqueous ink jet ink composition is 1000 particles/ml or less when 40% by mass of the water evaporates.
4. The ink jet recording method according to claim 1 , wherein a content of an organic solvent in which the difference in the solubility parameter values from the dispersant resin or the resin of the resin fine particles is within 2 is 5 to 20% by mass.
5. The ink jet recording method according to claim 1 , wherein a content of an organic solvent in which the difference in the solubility parameter values between the dispersant resin and the resin of the resin fine particles is within 2 is 10% by mass or less.
6. The ink jet recording method according to claim 1 , wherein the difference in the solubility parameter values between the dispersant resin and the resin of the resin fine particles is 0.5 or more and 2 or less.
7. The ink jet recording method according to claim 1 , further comprising:
applying a reaction liquid to the recording medium prior to discharging the aqueous ink jet ink composition to the reaction liquid.
8. The ink jet recording method according to claim 1 , wherein the ink jet head has a nozzle density of 300 dpi or more.
9. The ink jet recording method according to claim 1 , further comprising:
recording for at least 1 hour without performing a supplemental cleaning process by an external mechanism independent of the ink jet head.
10. The ink jet recording method according to claim 1 , wherein a content of the nitrogen-containing solvent is 5 to 15% by mass based on the total mass of the aqueous ink jet ink composition.
11. The ink jet recording method according to claim 1 , wherein the aqueous ink jet ink composition includes a glycol as the organic solvent.
12. The ink jet recording method according to claim 11 , wherein a content of the glycol is 5% by mass or more, based on the total mass of the aqueous ink jet ink composition.
13. The ink jet recording method according to claim 1 , wherein a temperature of the recording medium upon application of the aqueous ink jet ink composition is 30 to 45° C.
14. The ink jet recording method according to claim 1 , wherein the dispersant resin includes styrene acrylic resin, and the resin of the resin fine particles includes styrene acrylic resin.
15. The ink jet recording method according to claim 1 , wherein a content of the dispersant resin is 0.5 to 5% by mass based on the total mass of the aqueous ink jet ink composition, and a content of the resin of the resin fine particles is 3 to 15% by mass based on the total mass of the aqueous ink jet ink composition.
16. The ink jet recording method according to claim 1 , wherein the step is formed in a range where a distance from a nozzle opening of the nozzle to the pressure chamber is within a range of 20 to 100 μm.
17. The ink jet recording method according to claim 1 , wherein a content of an organic solvent having a normal boiling point of 280° C. or more is no more than 2% relative to a total mass of the aqueous ink jet ink composition.
18. The ink jet recording method according to claim 1 , wherein the aqueous ink jet ink composition includes a polyolefin wax.