| 1. An ink cartridge for storing ink, comprising a thermal ink-jet head provided with a heat generating portion that generates
thermal energy for ejecting the ink from an ejection opening, wherein:
the heat generating portion has, on its surface in contact with the ink, a protective layer containing at least one selected
from the group consisting of a silicon nitride and a silicon carbide; and
the ink contains a substance that dissolves the protective layer and a compound represented by the following general formula
(1), and a content X (% by mass) of the compound represented by the general formula (1) in the ink satisfies a relationship
of 1≤X≤30:
where A represents an alkylene or alkenylene group having 1 to 4 carbon atoms which forms a ring with a nitrogen atom, a carbonyl
group and R3, R1 and R4 each independently represent any one of a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted
or unsubstituted alkenyl group, a substituted or unsubstituted acyl group, a carbamoyl group, a substituted or unsubstituted
carboxyl group, and a substituted or unsubstituted sulfonyl group, R2 represents a group bonded to an arbitrary carbon atom of A, R2 representing any one of a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted
alkenyl group, a substituted or unsubstituted acyl group, a carbamoyl group, a substituted or unsubstituted carboxyl group,
and a substituted or unsubstituted sulfonyl group, n represents an integer of 0 to 4, and R3 represents a carbon or nitrogen atom.
|