| 摘要 |
PURPOSE:To reduce the foaming of a dispersion, to also reduce a particle size and to improve not only color forming sensitivity but also light fastness by using a coupler composed of a polyvalent metal salt of ring substituted salicylic acid formed by adding a vinyl group-containing cyclic compound to salicylic acid in the presence of aliphatic sulfonic acid. CONSTITUTION:One mol of salicylic acid and at least 1.5mol of a vinyl group- containing cyclic compound are reacted in the presence of aliphatic sulfonic acid and the obtained reaction product is further reacted with a polyvalent metal salt of an inorg. acid or lower aliphatic carboxylic acid. As the vinyl group-containing cyclic compound, pref., styrene and alpha-methylstyrene are designated. The use amount of aliphatic sulfonic acid is pref. 0.03-1mol. per one mol of salicylic acid. The mol ratio of the vinyl group-containing cyclic compound is pref. 2.0-22 mol per one mol of salicylic acid. The polyvalent metal salt of ring substituted salicylic acid can be prepared, for example, by reacting an alkali metal salt of ring substituted salicylic acid and a multivalent metal salt in an aqueous solvent. |
