| 摘要 |
<p>PURPOSE:To obtain a recording liquid, comprising an aqueous medium and at least one of specific azo dyes, used for ink jet recording and writing utensils and capable of providing black records at a high color density and excellent in printing quality when recorded on plain paper. CONSTITUTION:This recording liquid is obtained by mixing (A) an aqueous medium composed of diethylene glycol, isopropyl alcohol and water with (B) at least one azo dye expressed by the formula [A is phenyl or naphthyl which may have one or more substituent groups such as amino, acylamino, hydroxyl, COOM (M is H, alkali metal NH4 or organic amine salt), SO3M, etc.; X and Y are H, 1-7C (substituted)alkyl or 1-9C (substituted)alkoxy; the sum total of carbon atoms in X and Y is >=3; Z is H, (substituted)phenyl, the formula CH2 COOM, etc.; (n) is 0 or 1], regulating the pH to 9 with aqueous ammonia, then filtering the regulated solution through a filter having 1mum pore diameter under pressure and subjecting the filtrate to deaeration treatment with a vacuum pump, etc.</p> |
