CHARGE CONTROLLING AGENT, TONER BINDER COMPOSITION AND ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER

摘要

PROBLEM TO BE SOLVED: To obtain a charge controlling agent which is colorless and contains no heavy metals and with which an enough charge amt. and electrification rising can be obtd. in a small amt. of addition and excellent environmental stability is obtd. by using a specified polymer material to constitute the agent and specifying the ratio of the dielectric loss to the dielectric const. of the polymer material and the absorptivity for water of the polymer material. SOLUTION: This charge controlling agent consists of a polymer material (A) containing monomers having ester groups of org. acids as a structural unit. The ratio of the dielectric loss to the dielectric const. [tanδ] of the polymer (A) at 100kHz measuring frequency is specified to 0.01-0.3 and the absorptivity [w] for water is specified to <5wt.%. The monomers containing ester groups of org. acids are monomers containing sulfonate groups, monomers containing carboxylate groups, monomers containing sulfamate groups, monomers containing sulfate groups, monomers containing phosphate groups, etc. As for monomers containing sulfonate groups, a monomer containing aromatic sulfonate groups or a monomer containing aliphatic sulfonate groups can be used.