| 摘要 |
PURPOSE:To obtain a light fading inhibitor for organic colored substances such as a dye or a coloring matter by treating a crude product containing a nitrogen-containing heterocyclic derivative having a branched long-chain alkyl group with a protonic acid. CONSTITUTION:A crude product containing a compound expressed by the formula [Z is nonmetallic atomic group required to form a 5- to 7-membered heterocyclic ring together with N; R is >=8C branched alkyl; X1 and X2 are bivalent connecting group; Ar is aryl; (l), (m) and (n) are 0 or 1] is treated with a protonic acid (e.g. an alkylsulfonic acid) in an organic solvent (e.g. methanol) and the compound expressed by the formula is then isolated with a base (e.g. sodium carbonate). The organic colored substance is used in the field of printing, photography, color copy, etc., and the light fading inhibitor is extremely useful for preserving image quality and preventing the organic colored substance from fading. |
