| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a permeation dryness type printing ink which can reproduce a wider color region than the color reproduction region of RGB expressed by a conventional yellow, red, indigo and black ink process four color printing method. <P>SOLUTION: This offset ink composition comprises a yellow ink, a red ink, an indigo ink, and a black ink. The yellow ink contains 5 to 15% of C.I. pigment yellow 12 or C.I. pigment yellow 13 as a disazoyellow-based compound, and has transparency having an L*value not exceeding 31, when reprinted in a concentration of 0.85 to 1.00 on newspaper Japan color standard paper of ISO standard printed with a black ink in a concentration of 1.10 to 1.20. The red ink contains C.I. pigment red 169 as a metal chelate compound of rhodamine-based dye in a concentration of 10 to 30%. The indigo ink contains 10 to 25% of C.I. pigment blue 15:3 or C.I. pigment blue 15:4 and/or 0.5 to 2.0% of C.I. pigment green 7 as a phthalocyanine-based compound. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
