An ink-jet recording apparatus has an ink passage into which a water-based
ink or a preservation solution is filled. The ink passage employs a
rubber member formed from a rubber in which a butyl rubber polymer
serving as a base polymer, zinc oxide serving as a vulcanization agent,
and a thiourea-based compound serving as a vulcanization accelerator are
employed. Each of the water-based ink and the preservation solution
comprises water and a water-soluble organic solvent. The ink and the
preservation solution contain water in an amount of 70 wt. % to about 85
wt. % with respect to the total weight of the water-based ink and the
preservation solution, respectively.