| 摘要 |
PROBLEM TO BE SOLVED: To provide a recording liquid containing a pigment expressed by a specific formula as a free acid in an aqueous medium, useful as a writing utensil, etc., giving a black recorded image having high density, light-resistance and water-resistance and exhibiting high storage stability. SOLUTION: This recording liquid is composed of an aqueous medium containing a pigment expressed, as free acid, by either one of the formulas I to IV [R1 and R2 are each COOH or CONR15 R16 ; R8 and R9 are each COOH or CONR17 R18 ; A, B, C and D are each a group of the formula V, etc,; R3 , R6 , R10 and R13 are each H, a (substituted)phenyl or a (substituted) 1-3C alkyl; R5 , R12 and R15 to R18 are each H or a (substituted)alkyl; R19 and R20 are each COOH or CONR22 R23 ; R21 to R23 are each H or a (substituted) 1-9C alkyl; (l), (m), (n) and (p) are each 0 or 1]. The amount of the pigment is e.g. 2-4wt.% based on the total recording liquid. |
