| 摘要 |
<p>PURPOSE:To obtain a black ink compsn. which is excellent in injection characteristics, causes no clogging, has a satisfactory black color tone and is excellent in water resistance and light resistance, by using a particular dye as a coloring matter component. CONSTITUTION:The titled compsn. contains, as a coloring matter component, at least one dye of the formula (wherein R1 and R2 are each H or SO3M, provided that R1 and R2 are not simultaneously H: and M is an alkali metal, H, an ammonium group or an org. ammonium group) in which the ratio of the absorbance at 485nm to that at 625nm is 0.510-0.630. The compsn. is obtd. by dissolving a dye, a wetting agent and various additives in water.</p> |
