Azo compound and method of preparing the azo compound

An azo compound having the following formula (I):

• A(E)n (I)
• wherein
• A represents a residue of an azo compound, bonded with n pieces of E group through one or more heteroatom being N or O and forming a part of the residue A;
• E independently represents —C(═O)—O—R1 wherein R1 represents a substituted or an unsubstituted alkyl group having 4 to 10 carbon atoms, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group or an aralkyl group;
• and
• n represents an integer of from 1 to 10;
• and
• wherein
• A is the residue of a compound having the following formula (II):
• B—(N═N-Cp)m (II)
• B represents a main backbone of an azo compound and B has the following formulae (III):
• R1 and R2 independently represent a hydrogen atom, a halogen atom, a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted alkoxy group, and a carboxyl group or an ester thereof;
• Cp represents a coupler component residue having the following formula (6):
• wherein X represents —OH, —N(R1)(R2) or —NHSO2—R3 wherein R1 and R2 independently represents a hydrogen atom or a substituted or an unsubstituted alkyl group, and R3 represents a substituted or an unsubstituted alkyl group or a substituted or an unsubstituted aryl group;
• Y1 represents a hydrogen atom, a halogen atom, a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or an unsubstituted sulfamoyl group or —CON(R4)(Y2) wherein R4 represents an alkyl group or its substituents, or a phenyl group or its substituents, and Z represents a ring hydrocarbon group or its substituents, or a heterocyclic group or its substituents;
• and
• m represents an integer of 2.