Antibiotic additive and ink composition comprising the same

An ink composition comprising a colorant, a solvent and an antibiotic additive, in which the antibiotic additive comprises a compound produced by chemically reacting an antibiotic substance having a structure of the following formula (I) with a predetermined additive.

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• in which, R1 is any one selected from the group consisting of a hydrogen atom, a hydroxy group, an amino group, a carboxyl group and salts thereof, a sulfonic acid group and salts thereof, and a phosphoric acid group and salts thereof;
• and
• R2, R3, R4, R5, R6 and R7 are each independently any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxy group, a nitro group, a cyano group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group and salts thereof, a sulfonic acid group and salts thereof, a phosphoric acid group and salts thereof, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkenyl group, a substituted or unsubstituted C1 to C30 alkynyl group, a substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C6 to C30 arylalkyl group, a substituted or unsubstituted C6 to C30 heteroaryl group and a substituted or unsubstituted C6 to C30 heteroarylalkyl group.