Patent ID: 6187490
Filing Date: 2001-02-13
Classification: G03G

Abstract:
A resin-coated carrier, comprising: carrier core particles and 0.01-2.0 wt. % based on the carrier core particles of a resin coating layer coating the carrier core particles, whereinthe carrier core particles comprise a ferrite component represented by formula (I) below:(Fe.sub.2 O.sub.3).sub.a (MnO).sub.b (MgO).sub.c (A).sub.d (I),wherein A represents a mixture of SrO, CaO and Al.sub.2 O.sub.3, and a, b, c and d are numbers representing mol fractions of associated components and satisfying: 0.4<a<0.6, 0.35<b<0.45, 0.07<c<0.12, 0.005<d<0.015, and a+b+c+d.ltoreq.1, andthe resin-coated carrier has an average particle size of 25-55 .mu.m.