| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ink having a good hue as a cyan ink and excellent light fastness and resistance to ozone and humidity and being suitable for ink jet recording. <P>SOLUTION: The ink contains a mixture of pigments of formula (1) (wherein M is a proton, an alkali metal ion, an alkaline earth metal ion, an onium ion of an organic amine or an ammonium ion; m is an integer of 1-4; n is an integer of 0-4; and m+n is an integer of 1-4), and the mixture meets the below-mentioned conditions 1-3 in measurement with a spectrophotometer under conditions of a D65 light source, a 2° visual field and a transmitting optical path length of 10 mm, with the intensity adjusted with N,N-dimethylformamide so that the maximum value of the absorbance lies in 1 to 2 abs, or in the range of wavelengths of 400-800 nm. Condition 1 means that in the absorption curve of the spectrophotometer in the range of wavelengths of 400-800 nm, there is one maximum absorption peak, λmax, and no absorption peak appears in the range of wavelengths of 640 nm or longer. Condition 2 means that taking the absorbance of λ1 as A and that of λ2 as B, A/B is ≥1.1. Condition 3 means the value of (λ2-λ1) is ≤48 nm. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
