Aqueous ink, ink set, ink jet recording method and ink jet recording apparatus
Provided is an aqueous ink that can record an image achieving both of high abrasion resistance and high color developability. The aqueous ink is an aqueous ink for ink jet including: a coloring material; and a resin particle. A resin for forming the resin particle includes a unit having an aromatic group, a unit having a cyano group, a unit derived from a (meth)acrylic acid ester having a branched alkyl group and a unit represented by the following general formula (1). In the following general formula (1), “n” represents the number of a repeating unit, R 1 represents an alkyl group and E represents the number of repeating units of an ethylene oxide group and satisfies E≥1.
1 . An aqueous ink for ink jet comprising:
a coloring material; and
a resin particle,
wherein a resin for forming the resin particle includes a unit having an aromatic group, a unit having a cyano group, a unit derived from a (meth)acrylic acid ester having a branched alkyl group, and a unit represented by the following general formula (1):
wherein, in the general formula (1), “n” represents the number of a repeating unit, R 1 represents an alkyl group, and E represents the number of repeating units of an ethylene oxide group and satisfies E≥1.
2 . The aqueous ink according to claim 1 , wherein a ratio (% by mass) of the unit having an aromatic group to the resin for forming the resin particle is 20.0% by mass or more to 50.0% by mass or less with respect to a total mass of the resin.
3 . The aqueous ink according to claim 1 , wherein a ratio (% by mass) of the unit having a cyano group to the resin for forming the resin particle is 5.0% by mass or more to 50.0% by mass or less with respect to a total mass of the resin.
4 . The aqueous ink according to claim 1 , wherein a ratio (% by mass) of the unit derived from a (meth)acrylic acid ester having a branched alkyl group to the resin for forming the resin particle is 10.0% by mass or more to 40.0% by mass or less with respect to a total mass of the resin.
5 . The aqueous ink according to claim 1 , wherein a ratio (% by mass) of the unit represented by the general formula (1) to the resin for forming the resin particle is 1.0% by mass or more to 10.0% by mass or less with respect to a total mass of the resin.
6 . The aqueous ink according to claim 1 , wherein a ratio W1 (% by mass) of the unit having an aromatic group to the resin for forming the resin particle and a ratio W2 (% by mass) of the unit represented by the general formula (1) thereto satisfy a relationship of 4.0≤W1/W2≤40.0.
7 . The aqueous ink according to claim 1 , wherein the unit having an aromatic group is a unit represented by the following general formula (2):
wherein, in the general formula (2), “x” represents the number of a repeating unit, R 2 's each independently represent an alkyl group or a halogen atom, and “y” represents an integer of from 0 to 5.
8 . The aqueous ink according to claim 1 , wherein the unit having a cyano group is a unit derived from at least one kind of monomer selected from the group consisting of acrylonitrile and methacrylonitrile.
9 . The aqueous ink according to claim 1 , wherein the unit derived from a (meth)acrylic acid ester having a branched alkyl group is a unit derived from 2-ethylhexyl(meth)acrylate.
10 . The aqueous ink according to claim 1 , wherein the alkyl group represented by R 1 in the general formula (1) has 9 or more to 14 or less carbon atoms.
11 . The aqueous ink according to claim 1 , wherein the number of the repeating units of the ethylene oxide group represented by E in the general formula (1) is 5 or more to 30 or less.
12 . The aqueous ink according to claim 1 , wherein a content (% by mass) of the resin particle in the aqueous ink is 1.0% by mass or more to 15.0% by mass or less with respect to a total mass of the ink.
13 . The aqueous ink according to claim 1 ,
wherein the aqueous ink further comprises a water-soluble organic solvent containing polyethylene glycol whose number of ethylene oxide groups is 4 or more, and
wherein the number (n1) of the ethylene oxide groups of the unit represented by the general formula (1) in the resin for forming the resin particle and the number (n2) of the ethylene oxide groups of the polyethylene glycol satisfy a relationship of 0.25n1/n2≤5.0.
14 . The aqueous ink according to claim 13 , wherein a mass ratio of a content (% by mass) of the resin particle in the aqueous ink to a content (% by mass) of the polyethylene glycol is 0.3 times or more to 5.0 times or less.
15 . An ink set for ink jet comprising a combination of an aqueous ink and an aqueous reaction liquid containing a reactant that reacts with the aqueous ink,
wherein the aqueous ink is the aqueous ink of claim 1 ,
wherein the coloring material is dispersed by an action of a carboxylic acid group,
wherein the resin further includes a unit having a carboxylic acid group, and
wherein the reactant is a polyvalent metal ion.
16 . An ink jet recording method comprising ejecting an ink from a recording head of an ink jet system to record an image on a recording medium, wherein the ink is the aqueous ink of claim 1 .
17 . The aqueous ink according to claim 1 , wherein a content (% by mass) of the coloring material in the aqueous ink is 0.5% by mass or more to 15.0% by mass or less with respect to a total mass of the ink.
18 . The aqueous ink according to claim 13 , wherein a content (% by mass) of the polyethylene glycol whose number of ethylene oxide groups is 4 or more in the aqueous ink is 1.0% by mass or more to 20.0% by mass or less with respect to a total mass of the ink.
19 . The aqueous ink according to claim 1 , wherein the resin particle does not include any coloring material.
20 . The aqueous ink according to claim 1 , wherein the coloring material comprises a pigment.
21 . The aqueous ink according to claim 20 , wherein the pigment comprises at least one of a (i) self-dispersible pigment in which an anionic group is bonded to its particle surface directly or through another atomic group, or (ii) a resin-dispersed pigment.
22 . The aqueous ink according to claim 20 , wherein the pigment comprises a resin dispersed organic pigment.
23 . The aqueous ink according to claim 20 , wherein the pigment comprises a self-dispersible carbon black in which an anionic group is bonded to its particle surface directly or through another atomic group.