Patent ID: 7527683

Claim:
An ink for ink-jet recording, comprising: at least one azo dye represented by formula (1); and at least one betaine surfactant, wherein A represents a five-membered heterocyclic group; B 1 and B 2 each represent one of —CR 1 ═ and —CR 2 ═, or one of B 1 and B 2 represent nitrogen atom and other represents one of —CR 1 ═ and —CR 2 ═; R 3 and R 4 each independently represent one member selected from the group consisting of 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 arylsufonyl group, and an sulfamoyl group; R 1 and R 2 each independently represent one member selected from the group consisting of 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, an acyl group, a hydroxyl group, an alkoxy group, an aryloxy group, a silyloxy group, an acyloxy group, a carbamoyloxy group, a heterocyclic oxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an alkylamino group, an arylamino group, a heterocyclic amino group, an acylamino group, a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, an aryloxycarbonylamino group, a nitro group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, a sulfamoyl group, a sulfo group, and a heterocyc lie thio group; R 1 and R 2 may be combined to form one of a five- membered ring and six-membered ring; R 3 and R 4 may be combined to form one of a five- membered ring and six-membered ring; a and e each independently represent one of an alkyl group, an alkoxy group and a halogen atom, and in case that both a and e are an alkyl group, the total number of carbon atoms constituting the alkyl group is 3 or more, and a and e may be further substituted; b, c and d each independently is the same as defined in R 1 and R 2 , a and b may be condensed with each other to form a cyclic structure, and e and d may be condensed with each other to form a cyclic structure; the compound represented by the formula (1) has at least one ionic hydrophilic group.