PURPOSE: To provide always high grade image quality with an excellent line image, resolving power, etc. without photographic fogs by constituting a titled compsn. of a magnetic carrier which contains inorg. particles as a core and of which the shell is coated with a polymer contg. magnetic powder and a magnetic toner contg. magnetic powder.
CONSTITUTION: This compsn. for a developer consists of a magnetic carrier of which the shell of the inorg. particle core 1 is coated with a polymer 2 contg. magnetic powder 3 and a magnetic toner 4 contg. magnetic powder. The same inorg. powder as the inorg. powder of a carrier for magnetic brush development is usable for the inorg. powder of the core 1. An acrylic resin, fluororesin, etc. are selected for the polymer 2 to meet the electrostatic charge characteristic. The same magnetic powder as the magnetic powder for the core 1 is usable for the powder 3 and is made to have 0.05 to 5μm grain size. The mixing ratio of the polymer 2 and the powder 3 is made 10:90W95:5 by volume. The magnetic carrier prepd. in such a way has ≥40emu/g satd. magnetization and 20W200μm average grain size.
HASHIMOTO TAKESHI
SAIKAWA TAKESHI
ISHII YUKIHIRO
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