| 摘要 |
PROBLEM TO BE SOLVED: To provide an intaglio ink which is an ink for an engraved steel die printing process including a polymeric organic binder and an infrared (IR) absorbing material, and which is usable for security printing.SOLUTION: An ink for an engraved steel die printing process is a pasty ink having a viscosity value of >3 Pa s, preferably >5 Pa s at 40°C, and including an IR absorbing material, wherein: the IR absorbing material is a transition element compound whose IR-absorption is a consequence of electronic transitions within a d-shell of transition element atoms or ions; the transition element is selected from a group of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu; the transition element is an ion selected from a group of ions constituted of Ti, VO, Cr, Fe, Ni, Co, and Cu; and the IR absorbing material absorbs light in the NIR region (700-1,100 nm) and is transparent in a region of 1,100-2,500 nm. |
