| 摘要 |
<p>PURPOSE:To obtain an emulsion ink which includes a surfactant of a specific HLB in the oil phase and is composed of a water-in-oil type emulsion with its aqueous phase thickened, thus showing high emulsion stability at elevated temperatures and excellent temperature dependence of ink flowability and image quality. CONSTITUTION:The ink is composed of an emulsion having 10 to 50wt.% of the oil phase and 90 to 50wt.% of the aqueous phase where the surfactant in the oil phase has 3 to 5.5 HLB and the aqueous phase is thickened so that the viscosity reaches 15 to 350 poise, The surfactant is preferably a nonionic one such as sorbitan higher fatty acid ester. In order to thicken the aqueous phase a water-soluble polymer is added to the aqueous phase comprising water, electrolytes, a preservative, a fungicide and an evaporation retarder. The water- soluble polymer is, for example, an acrylic acid resin, or acrylic acid resin derivative such as sodium polyacrylate.</p> |
