Electric charge exchange control medicine and development agent composition

摘要

PROBLEM TO BE SOLVED: To improve the environmental stability of chargeability, aging stability, developability and image transferability and to obtain an image high in quality by using an organic boron compound comprising a specified organic anionic component and a cationic component. SOLUTION: This negatively chargeable charge exchange control agent is made of the organic boron compound comprising an organic anionic component represented by formula and a cationic component smaller in the molecular size than the anionic component and selected from an ammonium action and an organic amine action. In the formula, each of R1 -R4 is, independently, an organic group (provided that, excluding the case that either of R1 -R4 is a phenyl group) and each of R1 and R2 , R3 and R4 may combine with each other to form a ring each together with the combining boron atom. Thus, the obtained charge exchange control agent can easily control a charge amount and a charge distribution, is high in a charge rising speed, superior in developability and image transferability and suitable for a color developer.