| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-in-oil (W/O) type emulsion ink for inkjet printing which is excellent in storage stability at high temperature. <P>SOLUTION: A water phase containing a water-soluble dye is dispersed in an oil phase containing a water-insoluble polar solvent having α value of 9 or more by use of a polygylceryl fatty acid ester including oleic acid or isostearic acid as a fatty acid moiety and having HLB of 7-14 as an emulsifier. The mixing amount of the emulsifier is 25-70 pts.wt. relative to 100 pts.wt. of the whole aqueous phase, and the concentration of the water-soluble dye in the water phase is 1/2 or more of the maximum solubility of the die. The water-insoluble polar solvent with α value of 9 or more is an ester-based solvent or an alcohol-based solvent, and the content is preferably 15-35 mass% of the total amount of the ink in the former case, and 5-15 mass% in the latter case. The emulsion ink is preferably composed of 40-99 mass% oil phase and 60-1 mass% water phase. <P>COPYRIGHT: (C)2013,JPO&INPIT |
