Carrier core material and carrier for electrophotographic developer and process for producing the same, and electrophotographic developer using the carrier
AssigneePowdertech Co., Ltd.
InventorsTakashi Kojima, Toru Iwata, Koji Aga
Life of this patent
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Abstract
Employment of a carrier core material for an electrophotographic developer containing 0.8 to 5% by weight of Mg, 0.1 to 1.5% by weight of Ti, 60 to 70% by weight of Fe and 0.2 to 2.5% by weight of Sr and having an amount of Sr dissolved with a pH4 standard solution of 80 to 1000 ppm, a carrier using the core material and a process for producing them, and an electrophotographic developer using the carrier.
Claims15
A carrier core material for an electrophotographic developer comprising 0.8 to 5 by weight of Mg, 0.1 to 1.5% by weight of Ti, 60 to 70% by weight of Fe, 0.1 to 10% by weight of Mn and 0.2 to 2.5% by weight of Sr, has an amount of Sr dissolved with a pH4 standard solution of 80 to 1000 ppm, and has a shape factor SF-2 (circularity) of 100 to 120.
A carrier core material for an electrophotographic developer comprising 0.8 to 5% by weight of Mg, 0.1 to 1.5% by weight of Ti, 60 to 70% by weight of Fe, 0.1 to 10% by weight of Mn and 0.2 to 2.5% by weight of Sr, and has an amount of Sr dissolved with a pH4 standard solution of 80 to 1000 ppm, wherein an average particle size is 15 to 120 μm when measured using a laser diffraction particle size distribution analyzer.
Dependencies are inferred from the claim text.