Carrier, developer, image forming apparatus and process cartridge

摘要

A carrier including a manganese ferrite core material; and a layer located on a surface thereof, wherein the following relationship is satisfied, 0.1 ≤ K ≤ 30 wherein K = (S/M) x 100 wherein S represents a standard deviation of M2/(M1+M2) and M represents an average thereof ranging from 0.05 to 0.45, and wherein M1 represents a content of iron in a carrier particle and M2 represents a content of manganese therein. The carrier has a magnetization of from 45 to 75 emu/g at 1,000 Oe; a weight-average particle diameter (D4) of from 25 to 65 mu m, wherein carrier particles having a particle diameter not greater than 12 mu m is included in an amount not greater than 0.3 % by weight; and a ratio (D4/D1) of (D4) to a number-average particle diameter of the carrier (D1) is from 1 to 1.3.