CARRIER CORE PARTICLES FOR ELECTROPHOTOGRAPHIC DEVELOPER, CARRIER FOR ELECTROPHOTOGRAPHIC DEVELOPER, ELECTROPHOTOGRAPHIC DEVELOPER AND METHOD FOR MANUFACTURING THE CARRIER CORE PARTICLES

摘要

The carrier core particles for electrophotographic developer include a core composition expressed by a general formula Fe3O4 as a main ingredient and 30 ppm to 400 ppm Na. Such carrier core particles can reduce environmental dependency thereof, while optimizing the resistivity.