Ink composition, ink set and recording method

1. An ink composition comprising:

a coloring material having an azo group bound to a heterocyclic group;

an aqueous medium; and

at least one of an acetylene diol and an ethylene oxide adduct of the acetylene diol,

wherein an average value of an addition molar number of the at least one of the acetylene diol and the ethylene oxide adduct of the acetylene diol is 0 or more and less than 4, and

the coloring material having an azo group bound to a heterocyclic group contains at least one of a compound represented by general formula (Y), a compound represented by general formula (Bk) and a compound represented by general formula (M):

(A-N═N-B) n -L   General Formula (Y)

in the formula, n is 2; A and B each independently represents an optionally substituted heterocyclic group, one of A and B represents a monovalent heterocyclic group, and the other represents a divalent heterocyclic group, and As may be the same or different, and Bs may be the same or different; and L represents a simple bond or a divalent connecting group;

A 1 -N═N-A 2 -N═N-A 3   General Formula (Bk)

in the formula, A 1 , A 2 and A 3 each independently represents an optionally substituted aromatic group or an optionally substituted heterocyclic group, provided that at least one of A 1 , A 2 and A 3 represents a heterocyclic group; A 1 and A 3 are each a monovalent group, and A 2 is a divalent group:

in the formula, A 31 represents a residue of a 5-membered heterocyclic diazo component A 31 -NH 2 ; B 31 and B 32 each each represents ═CR 31 - or —CR 32 ═, or either one of them represents a nitrogen atom, and the other 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 heterocyclic oxycarbonyl group, a carbamoyl group, an alkyl- or arylsulfonyl group, a heterocyclic sulfonyl group, or a sulfamoyl group, and each of these groups may be further substituted: 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 hydroxyl 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 (inclusive of an arylamino group and a heterocyclic amino group), an acylamino group, a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- or arylsulfonylamino group, a heterocyclic sulfonylamino group, a nitro group, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl- or arylsulfonyl group, a heterocyclic sulfinyl group, a sulfamoyl group, a sulfo group, or a heterocyclic thio group, and each of these groups may be further substituted; R 31 and R 35 , or R 35 and R 36 may be taken together to form a 5-membered or 6-membered ring.

2. The ink composition according to claim 1 , wherein a content of the at least one of the acetylene diol and the ethylene oxide adduct of the acetylene diol is from 5 to 50 g/L.

3. The ink composition according to claim 1 , wherein an oxidation potential of the coloring material is nobler than 1.0 V against a standard calomel electrode.

4. An ink set comprising an ink composition according to claim 1 .

5. A recording method comprising recording an image using an ink composition according to claim 1 .

6. A recording method comprising recording an image using an ink set according to claim 4 .

7. The recording method according to claim 5 , which is an inkjet recording method.

8. The recording method according to claim 6 , which is an inkjet recording method.