Ink jet recording method and ink jet recording apparatus
Provided is an ink jet recording method capable of recording an image excellent in color developability while suppressing ink deposition. The ink jet recording method includes ejecting an aqueous ink from an ejection orifice of a recording head based on image data to record an image on a recording medium and ejecting the heated ink to an ink receiving member from the ejection orifice based on preliminary ejection data. The aqueous ink contains a pigment and a resin dispersant for dispersing the pigment and satisfies at least one of requirement (1): the resin dispersant is a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less and requirement (2): the aqueous ink further contains a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less. The pigment is carbon black whose cumulative 50% particle size in volume-based particle size distribution is 80 nm or less.
1. An ink jet recording method comprising:
a recording step of ejecting an aqueous ink from an ejection orifice of a recording head, based on image data, to thereby record an image on a recording medium; and
a preliminary ejection step of heating the aqueous ink and ejecting the heated aqueous ink to an ink receiving member from the ejection orifice based on preliminary ejection data;
wherein the aqueous ink comprises a pigment and a resin dispersant for dispersing the pigment and satisfies at least one of the following requirements (1) and (2):
Requirement (1): the resin dispersant is a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less;
Requirement (2): the aqueous ink further comprises a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less, and
wherein the pigment is carbon black whose cumulative 50% particle diameter in a volume-based particle size distribution is 80 nm or less.
2. The ink jet recording method according to claim 1 , wherein the pigment has a BET specific surface area of 210 m 2 /g or less.
3. The ink jet recording method according to claim 1 , wherein the water-soluble acrylic resin has (i) a unit derived from a monomer having an aromatic group and (ii) a unit derived from a (meth)acrylic acid.
4. The ink jet recording method according to claim 1 , wherein the content (% by mass) of the water-soluble acrylic resin in the ink relative to the content (% by mass) of the pigment is 0.1 times or more in terms of mass ratio.
5. The ink jet recording method according to claim 1 , wherein the aqueous ink further comprises a water-soluble urethane resin.
6. An ink jet recording apparatus comprising:
an aqueous ink;
a recording head filled with the aqueous ink and ejecting the aqueous ink from an ejection orifice, based on image data, to thereby record an image on a recording medium; and
a preliminary ejection mechanism that heats the aqueous ink and ejects the heated aqueous ink to an ink receiving member from the ejection orifice based on preliminary ejection data,
wherein the aqueous ink comprises a pigment and a resin dispersant for dispersing the pigment and satisfies at least one of the following requirements (1) and (2):
Requirement (1): the resin dispersant is a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less;
Requirement (2): the aqueous ink further comprises a water-soluble acrylic resin having an acid value of 135 mgKOH/g or less, and
wherein the pigment is carbon black whose cumulative 50% particle diameter in a volume-based particle size distribution is 80 nm or less.
7. The ink jet recording method according to claim 1 , wherein the aqueous ink satisfies the requirement (1).
8. The ink jet recording method according to claim 1 , wherein the pigment has a cumulative 50% particle diameter in a volume-based particle size distribution of 55 nm or more.
9. The ink jet recording method according to claim 2 , wherein the pigment has a BET specific surface area of 100 m 2 /g or more.
10. The ink jet recording method according to claim 2 , wherein the pigment has a BET specific surface area of 150 m 2 /g or more.
11. The ink jet recording method according to claim 2 , wherein the pigment has a BET specific surface area of 155 m 2 /g or more.
12. The ink jet recording method according to claim 1 , wherein the content (% by mass) of the pigment in the ink is 1.0% by mass or more to 10.0% by mass or less based on the total mass of the ink.
13. The ink jet recording method according to claim 1 , wherein the acid value of the water-soluble acrylic resin is 80 mgKOH/g or more.
14. The ink jet recording method according to claim 1 , wherein the acid value of the water-soluble acrylic resin is 100 mgKOH/g or more.
15. The ink jet recording method according to claim 1 , wherein the water-soluble acrylic resin has a weight-average molecular weight of 5,000 or more to 10,000 or less.
16. The ink jet recording method according to claim 1 , wherein the content (% by mass) of the water-soluble acrylic resin in the ink is 0.5% by mass or more to 2.5% by mass or less based on the total mass of the ink.
17. The ink jet recording method according to claim 1 , wherein the content (% by mass) of the water-soluble acrylic resin in the ink relative to the content (% by mass) of the pigment is 5.0 times or less in terms of mass ratio.
18. The ink jet recording method according to claim 1 , wherein heating the aqueous ink in the preliminary ejection step is controlled so as to adjust the temperature of the aqueous ink ejected based on preliminary ejection data to 40° C. or more to 70° C. or less.
19. The ink jet recording method according to claim 1 , wherein heating the aqueous ink in the preliminary ejection step is performed by applying a current to a heater for ink ejection that is small enough not to eject the aqueous ink and to thereby control the temperature of the recording head.