Generation of Charge-control Ability of Pararosaniline Due to Protonation and its Protonation Mechanism

抄録

Triphenyl-pararosaniline (TPPR)is a charge-control agent (CCA) of the positive type for toners in the electrophotographic process. Suganami et al. reported that the charge control ability of TPPR is greatly improved if TPPR forms a charge-transfer (CT) complex with CCAs of the negative type, as those of n-propyl gallate (TPPR/PG=1/2), 3,5-di-tert-butylsalicylate zinc complex (TPPR/SZC=1/3) and 3,5-di-tert-butylsalicylate (TPPR/TBS=1/6). On the contrary, we interpret here the enhanced charge-control ability as arising from protonation of TPPR due to phenolic hydroxides of TBS, SZC and PG. The ratio of TPPR to these acids can be explained in terms of their effective acidity weakened significantly by intra-and intermolecular hydrogen bonds in the solid state, as revealed from structure analysis of these acids.