Abstract: A carrier for a developer comprising a core material coated with a coating material consisting essentially of a copolymer of vinylidene fluoride and trifluoroethylene or hexafluoropropylene is disclosed. The carrier causes neither fog generation in the initial stage of running nor contamination of a developing machine because of its high rate of charge increase and satisfactory resistance to surface contamination, and exhibits excellent adhesion between the core material and the coating material.

Abstract: A toner for development of a latent electrostatic image containing a colorant and a binder resin formed of a mixture of a low-molecular weight component and a high-molecular weight component. Both the low-molecular weight component and high-molecular weight component are made from a styrene-acrylic copolymer where the weight ratio (A) of styrene to acrylic monomer in the low-molecular weight polymer component and an the weight ratio (B) of styrene to acrylic monomer in the high-molecular weight polymer component satisfies the relationship A/B.ltoreq.1.3. The mixing ratio of the low-molecular weight and high-molecular weight components is within the range of from 80:20 to 40:60. The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) of the low-molecular weight polymer component satisfies the relationship Mw/Mn.ltoreq.3.0.

Abstract: A carrier for a developer comprising a core material coated with a coating material consisting essentially of a copolymer of vinylidene fluoride and trifluoroethylene or hexafluoropropylene is disclosed. The carrier causes neither fog generation in the initial stage of running nor contamination of a developing machine because of its high rate of charge increase and satisfactory resistance to surface contamination, and exhibits excellent adhesion between the core material and the coating material.

Abstract: A negative charging carrier for an electrophotographic developer is described, comprising a binder resin having dispersed therein a magnetic powder, wherein said carrier contains a fluorine-containing resin fine powder in an amount of from 5 to 50% by weight based on the total weight of the carrier. The carrier provides a developer for magnetic brush development having a prolonged life and a high rate of development.