| 摘要 |
<p>PURPOSE: To obtain an ink composition which can be kept in the state of a solution even when it is contaminated with water by using ethanol as the main solvent and using a solvent having a function of mixing ethanol with water as the subsidiary solvent. CONSTITUTION: This ink composition is prepared by dissolving a specified amount of a binder resin such as a styrene/acrylic resin, a specified amount of a dye and a specified amount of a conductivity improver such as Li2 SO4 in a liquid medium comprising a main solvent such as ethanol and a subsidiary solvent having a function of mixing ethanol with water and selected from among dimethyl sulfoxide, N-methylpyrrolidone, etc. This composition is sucked and pressurized with a feed pump 7, fed into a nozzle 3 and vibrated by a specified electric signal applied to an electrostrictive element 2. The vibrated ink is then jetted through an orifice and forms ink particles 10 between charging electrodes 4. The particles are electrostatically deflected while they are passing a deflection electrodes 9 to which a specified electric power is applied and jetted against a printing substrate 5 to form characters thereon. That part of the ink which does not take part in the formation of characters is received in a gutter 11 and returned to an ink bottle 8 with a return pump 6.</p> |
