Ink for ink jet recording, ink set for ink jet recording and ink jet recording method

1. An ink for ink jet recording, comprising an aqueous medium and a magenta dye dissolved or dispersed in the aqueous medium, the magenta dye being selected from azo dyes,

wherein the magenta dye has an absorption maximum in a spectral range of from 500 to 580 nm in the aqueous medium and an oxidation potential of more positive than 1.0 V (vs SCE), and

the azo dye is a dye represented by the following formula (1): Formula (1)

wherein A represents a 5-membered heterocyclic ring group; B 1 and B 2 each represents ═CR 1 — or —CR 2 ═ or one of B 1 and B 2 represents a nitrogen atom while other represents ═CR 1 — or —CR 2 ═; R 5 and R 6 each independently represents a hydrogen atom or a substituent which is an aliphatic group, an aromatic group, a heterocyclic ring, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group or a sulfamoyl group, a hydrogen atom of the substituent may be substituted: G, R 1 and R 2 each independently represents a hydrogen atom or a substituent which is a halogen atom, an aliphatic group, an aromatic group, a heterocyclic ring 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 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, a heterocyclic thio group, an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group or a sulfo group, wherein a hydrogen atom of the substituent may be substituted; and R 1 and R 5 or R 5 and R 6 may be connected to each other to form a 5- or 6-membered ring.

2. The ink for ink jet recording according to claim 1 , wherein the azo dye has one of an aromatic cyclic amino group and a heterocyclic amino group-containing structure as an auxochrome.

3. The ink for ink jet recording according to claim 1 , wherein the azo dye has a stereostructure.

4. The ink for ink jet recording according to claim 1 ,

wherein the ink has an ozone fading rate constant of a recorded image, the ozone fading rate constant is 5.0×10 −2 [hr −1 ] or less.

5. The ink for ink jet recording according to claim 1 , which has a viscosity of from 1 to 20 mPa·sec at 25° C.

6. The ink for ink jet recording according to claim 1 , which has a static surface tension of from 25 to 50 mN/m at 25° C.

7. The ink for ink jet recording according to claim 1 , which has an electrical conductance of from 0.01 to 10 S/m.

8. The ink for ink jet recording according to claim 1 ,

wherein a change of a viscosity and a surface tension of the ink from at 25° C. to at 10° C. are 250% or less and 130% or less, respectively.

9. The ink for ink jet recording according to claim 1 ,

wherein the ink has no visibly detectable bleeding on an image-receiving material at a visible distance, the image-receiving material comprises an image-receiving layer on a support, and the image-receiving layer contains a white inorganic pigment particle.

10. The ink for ink jet recording according to claim 1 ,

which has no visibly detectable bleeding on an image-receiving material at a visible distance, the image-receiving material comprising a gelatin-containing hardened layer as an image-recording layer.

11. A method for producing the ink for ink jet recording according to claim 1 ,

which comprises a step of dissolving or dispersing the azo dye in the aqueous medium with an ultrasonic agitation.

12. A method for producing the ink for ink jet recording according to claim 1 ,

which comprises steps of: filtering the aqueous medium having the azo dye dissolved or dispersed in the aqueous medium through a filter having an effective pore diameter of 1 μm or less; and defoaming the filtered aqueous medium.

13. An ink jet recording method using the ink for ink jet recording according to claim 1 .

14. The ink jet recording method according to claim 13 ,

wherein an ink droplet is ejected onto an image-receiving material in accordance with a recording signal so that an image is recorded on the image-receiving material by using the ink for ink jet recording, the image-receiving material comprising an image-receiving layer on a support, the image-receiving layer containing a white inorganic pigment particle.

15. The ink jet recording method according to claim 14 ,

wherein the image-receiving layer contains the white inorganic pigment particle and at least one aqueous binder selected from the group consisting of a polyvinyl alcohol, a silanol-modified polyvinyl alcohol, a starch, a cationated starch, a gelatin, a carboxyalkyl cellulose, a casein and a polyvinyl pyrrolidone.

16. The ink jet recording method according to claim 15 , wherein the image-receiving layer further contains a mordant selected from the group consisting of a polyaluminum chloride, a chromium compound and an azo dye-mordanting group-containing polymer.