| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reliable ink composition having stable printing properties, with which crystal deposition of pigments in an ink is suppressed, and clogging at an ink discharging port is eliminated. <P>SOLUTION: An ink contains a urea-based compound and at least one kind of azo compounds represented by formula (1) in an aqueous medium. (In the formula, A represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted nitrogen-containing five-membered heterocyclic group. G represents a nitrogen atom or -C(R<SB POS="POST">2</SB>)=. R<SB POS="POST">2</SB>represents a hydrogen atom, a sulpho group, a carboxy group, a substituted or unsubstituted carbamoyl group or a cyano group. Y<SB POS="POST">2</SB>, Y<SB POS="POST">3</SB>and Y<SB POS="POST">4</SB>each independently represent a hydrogen atom or a monovalent substituted group. Y<SB POS="POST">2</SB>, Y<SB POS="POST">3</SB>and Y<SB POS="POST">4</SB>may link with each other and form a ring. Y<SB POS="POST">2</SB>, Y<SB POS="POST">3</SB>and Y<SB POS="POST">4</SB>do not all represent a hydrogen atom at the same time. M each independently represents a hydrogen atom or a monovalent counter cation). <P>COPYRIGHT: (C)2012,JPO&INPIT |
