Abstract: A toner composition for thermal fixing is disclosed, comprising a colorant, an external additive and a binder resin that contains a thermoplastic resin having a glass transition point of from 20.degree. C. to less than 50.degree. C. and a polyolefin polymer having an average molecular weight of 800 or more, the polyolefin polymer being present in an amount of from 5 wt % to less than 50 wt % of the total binder resin.

Abstract: A dry developer for an electrophotographic process, said dry developer being composed of a toner and a dispersion type carrier composed of a resin and a magnetic powder, wherein polyethylene having a molecular weight of not larger than 10,000, a density of at least 0.95, and an average volume diameter of not larger than 15 .mu.m is externally added to the toner or directly mixed with the developer. The dry developer shows good fluidity and cleaning property, is excellent in environmental stability and durability, and can prevent the occurrence of the toner film phenomenon on a photoreceptor or carrier surfaces.

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.