| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide black ink which is used for inkjet recording and gives images having excellent quality, excellent durability and excellent ejection stability. <P>SOLUTION: This black ink, which is used for the inkjet recording and prepared by dissolving and/or dispersing at least one dye having λmax of 500 to 700nm and a half value width of ≥100nm in the absorption spectrum of a diluted solution standardized at an absorbance of 1.0 in an aqueous solvent, is characterized by containing a surfactant of 0.05 to 50g/L and having a forced fading rate constant (k<SB>vis</SB>) of ≤5.0×10<SP>-2</SP>[hour<SP>-1</SP>], when the rate constant (k<SB>vis</SB>) is obtained by printing JIS code 2223 black square mark at 48 points with the black ink, forcefully fading the printed product with an ozone fading tester capable of always producing 5 ppm ozone, and then determining the forced fading rate constant (k<SB>vis</SB>) from a time until a reflection concentration (D<SB>vis</SB>) becomes 80% of an initial concentration value. <P>COPYRIGHT: (C)2004,JPO |
