Abstract: A charge control agent comprises a barbituric acid derivative represented by the following general formula (1): wherein R1 to R8 are alkyl groups, cycloalkyl groups or aryl groups, V, W, X, Y and Z are carbon atoms or nitrogen atoms, at least two of which being carbon atoms, and p, q, r, s and t are the numbers of 0 or 1.

Abstract: [Problems] To provide a charge control agent which contains no heavy metal component, therefore, does not adversely affect the environment and, besides, is colorless or is light-colored lending itself well to be applied to colored toners, and is little affected by the environmental conditions, and exhibits the effect of imparting high charging power even when it is used for polymerized toners. [Means for Solution] The charge control agent comprises a barbituric acid derivative represented by the following general formula (1): wherein R1 to R8 are alkyl groups, cycloalkyl groups or aryl groups, V, W, X, Y and Z are carbon atoms or nitrogen atoms, at least two of which being carbon atoms, and p, q, r, s and t are the numbers of 0 or 1.

Abstract: A negatively charged polymerized toner having high charging performance, which comprises a charge control agent particularly useful for color toners and polymerized toners, the charge control agent comprising a cyclic phenol sulfide as an active ingredient, which speeds up charging risetime, has a high charge amount and charging characteristics particularly excellent in environmental stability, and is safe since it does not have any problem with the waste regulations.