| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject ink, good in color tone as a black color of a record and having a high recording density by blending the first and the second dyes capable of providing a transmitted color, passed through each aqueous solution of the dyes at a dye concentration regulated within a specific range and satisfying specific conditions. SOLUTION: This water-based black ink for recording comprises the first dye providing a transmitted color of an aqueous solution of the dye at dye concentration regulated to >=0.005 to <=0.05wt.% with <=4L*, <=25C*ab and >=350 deg. and <=10 deg. hue angle H deg. in an L*a*b color system under measuring conditions of a D65 light source, 2 deg. visual field and 10mm transmitted optical path length and the second dye providing >=230 deg. and <=280 deg. hue angle H deg.. The water-based black ink for recording is prepared by blending the first and second dyes so that the transmitted light of an aqueous solution obtained by diluting the water-based black ink with pure water or ion exchange water to 200 times may have preferably <=5C*ab, more preferably <=1L* in the L*a*b* color system under the measuring conditions. |
