| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject ink having excellent stability, giving high printing density and causing little stain of the printed matter by blocking, etc., by adding hydrophobic solid particles having specific particle diameter to the oil phase of a W/O-type emulsion ink containing a water-insoluble colorant in the water phase. SOLUTION: This W/O-type emulsion ink contains a water-insoluble colorant (preferably a colorant having high affinity to water such as carbon black) in the water phase and hydrophobic solid particles having an average diameter of 2-20μm (preferably particles uniformly dispersible in the oil phase such as hydrophobicized silica) in the oil phase in an amount of 0.1-5wt.% based on the total ink. The hydrophobic particle is preferably a colorless transparent spherical particle. The oil phase is usually composed of a non-volatile solvent, a volatile solvent, an emulsifier, etc., in addition to the above particles, however, it is preferable to incorporate the oil phase with a resin such as an alkyd resin to improve the blocking resistance of the ink.</p> |
