Ink for inkjet printing ink set for inkjet printing inkjet recording material and producing method for inkjet recording material and inkjet recording method

1 . An ink for inkjet printing, which comprising:

at least one of water and a water-miscible organic solvent;

a dye; and

a compound represented by formula (A):

wherein R 1 , R 2 and R 3 each represents an alkyl group, an aryl group or a heterocyclic group, and at least two of R 1 , R 2 and R 3 are mutually connected to form a cyclic structure; L represents a divalent connecting group; and at least one of R 1 , R 2 , R 3 and L is a group having 8 or more carbon atoms.

2 . The ink for inkjet printing according to claim 1 , wherein the dye is at least one selected from the group consisting of dyes represented by formulae (1) to (4):

wherein in formula (1),

A 1 , and B 11 each independently represents a heterocyclic group that may be substituted;

n represents 1 or 2; and

L represents a hydrogen atom, a monovalent substituent, a single bond or a divalent connecting group,

wherein when n is 1, L represents a hydrogen atom or a monovalent substituent and A 11 and B 11 are both monovalent heterocyclic groups; and

when n is 2, L represents a single bond or a divalent connecting group, A 11 represents a monovalent heterocyclic group and B 11 is a divalent heterocyclic group;

in formula (2),

X 21 , X 22 , X 23 and X 24 each independently represent —SO-Z 2 , —SO 2 -Z 2 , —SO 2 NR 21 R 22 , a sulfo group, —CONR 21 R 22 , or —COOR 21 , wherein Z 2 independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group or a heterocyclic group, each of which may be further substituted; and R 21 and R 22 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group or a heterocyclic group, each of which may be further substituted;

Y 21 , Y 22 , Y 23 and Y 24 each independently represents a monovalent substituent;

a 21 , a 22 , a 23 and a 24 represent the number of X 21 's, X 22 's, X 23 's and X 24 's, respectively, and each independently represents a number of 0 to 4, provided that all of a 21 , a 22 , a 23 and a 24 are not 0 at the same time, wherein when any of a 21 , a 22 , a 23 and a 24 is 2 or more, a plurality of X 21 's, X 22 's, X 23 's and X 24 's is mutually the same or different;

b 21 , b 22 , b 23 and b 24 represent the number of Y 21 's, Y 22 's, Y 23 's and Y 24 's, respectively, and each independently repersents a number of 0 to 4, wherein when any of b 21 , b 22 , b 23 and b 24 is 2 or more, a plurality of Y 21 's, Y 22 's, Y 23 's and Y 24 's is mutually the same or different; and

M represents a hydrogen atom, a metal atom, a metal oxide, a metal hydroxide or a metal halide;

in formula (3),

A 31 represents a 5-membered heterocyclic ring;

B 31 and B 32 each represents ═CR 31 — or —CR 32 ═, or either one of B 31 and B 32 represents a nitrogen atom while the other one represents ═CR 31 — or —CR 32 ═;

R 35 and R 36 each independently represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group, each of which may further have a substituent;

G 3 , R 31 and R 32 each independently represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group, a cyano group, a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group, a hydroxy group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, an arylamino group, a heterocyclic amino group, an acylamino group, an ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a heterocyclic sulfonylamino group, a nitro group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinyl group, an aryl sulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, a sulfo group or a heterocyclic thio group, each of which may be further substituted; and

R 31 and R 35 , or R 35 and R 36 may be bonded to form a 5- or 6-membered ring; and

in formula (4),

A 41 , A 42 and A 43 each independently represents an aromatic group or a heterocyclic group, each of which may be further substituted; A 41 and A 43 are monovalent groups, while A 42 is a divalent group.

3 . The ink for inkjet printing according to claim 2 , wherein the dye represented by formula (2) is a dye represented by formula (5):

wherein X 51 , X 52 , X 53 , X 54 , and M 1 have the same meaning as X 21 , X 22 , X 23 , X 24 , and M in formula (2), respectively; Y 51 and Y 52 have the same meaning as Y 21 in formula (2); Y 53 and Y 54 have the same meaning as Y 22 in formula (2); Y 55 and Y 56 have the same meaning as Y 23 in formula (2); Y 57 and Y 58 have the same meaning as Y 24 in formula (2); and a 51 , a 52 , a 53 and a 54 each independently represents an integer 1 or 2.

4 . An ink set for inkjet printing, which comprises an ink according to any one of claims 1 to 3 .

5 . An inkjet recording material, which comprises: a substrate; and an ink receptive layer on the substrate,

wherein the ink receptive layer includes a compound represented by formula (A):

wherein R 1 , R 2 and R 3 each represents an alkyl group, an aryl group or a heterocyclic group, and at least two of R 1 , R 2 and R 3 are mutually connected to form a cyclic structure; L represents a divalent connecting group; and at least one of R 1 , R 2 , R 3 and L is a group having 8 or more carbon atoms.

6 . The inkjet recording material according to claim 5 , wherein the ink receptive layer further contains a water-soluble resin.

7 . The inkjet recording material according to claim 6 , wherein the water-soluble resin is at least one selected from the group consisting of a polyvinyl alcohol resin, a cellulose resin, a resin including an ether bond, a resin including a carbamoyl group, a resin including a carboxyl group, and a gelatin.

8 . The inkjet recording material according to claim 6 or 7 , wherein the ink receptive layer includes a crosslinking agent capable of crosslinking the water-soluble resin.

9 . The inkjet recording material according to any one of claims 5 to 8 , wherein the ink receptive layer further includes a fine particle.

10 . The inkjet recording material according to claim 9 , wherein the fine particle is at least one selected from the group consisting of a fine silica particle, a colloidal silica, a fine alumina particle and a pseudo-boehmite.

11 . The inkjet recording material according to any one of claims 5 to 10 , wherein the ink receptive layer further includes a mordant agent.

12 . The inkjet recording material according to any one of claims 5 to 11 , wherein the ink receptive layer is a cured layer formed by:

applying a first solution on a substrate to form a coating layer, the first solution containing a fine particle, a water-soluble resin, and a crosslinking agent; and

applying a second solution on the coating layer, the second solution having a pH of 8 or more, so that the coating layer is cured by a crosslinking reaction to form the cured layer,

wherein the applying of the second solution is performed one of:

(1) at the same time as the applying of the first solution; and

(2) in the course of drying the coating layer and before the coating layer starts to show a falling drying rate.

13 . An inkjet recording method, which comprises discharging a droplet of an ink according to any one of claims 1 to 3 on an inkjet recording material, so as to form an image or a character.

14 . An inkjet recording method, which comprises discharging a droplet of an ink on an inkjet recording material according to any one of claims 5 to 12 , so as to form an image or a character.

15 . An inkjet recording method according to claim 14 , wherein at least one ink contains a betaine compound.

16 . The inkjet recording method according to claim 15 , wherein the betaine compound is a compound represented by formula (A) according to claim 5 .

17 . The inkjet recording method according to claim 15 , wherein at least one ink is an ink according to any one of claims 1 to 3 .

18 . A method for producing an inkjet recording material, which comprises:

applying a first solution on a substrate to form a coating layer, the first solution containing a fine particle, a water-soluble resin, and a crosslinking agent; and

applying a second solution on the coating layer, the second solution having a pH of 8 or more, so that the coating layer is cured by a crosslinking reaction to form a ink receptive layer,

wherein the applying of the second solution is performed one of:

(1) at the same time as the applying of the first solution; and

(2) in the course of drying the coating layer and before the coating layer starts to show a falling drying rate.