| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a higher printing concentration particularly on a usual paper in an inkjet printing system using an emulsion ink. <P>SOLUTION: In an inkjet printing method where after one of the first ink and the second ink is discharged on a printing medium, the other ink is jetted continuously so as to overlay it on the one ink, the first ink described above is a water in oil (W/O) type emulsion ink in which a coloring matter with an acid group on the surface is contained in a water phase, and the second ink described above is a water in oil type (W/O) emulsion containing a polyvalent metal salt in the water phase. The preferable acidic group is carboxylic acid group, sulfonic acid group and phosphonic acid group. The preferable polyvalent metal salt is a salt comprising a metallic ion such as Ca<SP>++</SP>, Cu<SP>++</SP>, Ni<SP>++</SP>, Mg<SP>++</SP>, Zn<SP>++</SP>, Ba<SP>++</SP>, Al<SP>+++</SP>, Fe<SP>+++</SP>or Cr<SP>+++</SP>. <P>COPYRIGHT: (C)2010,JPO&INPIT |
