Abstract: A non-magnetic one-component developer comprising a binder resin, a colorant and a charge controlling agent, the binder resin being a polyester resin which has a number average molecular weight of from 2,500 to 3,500, a weight average molecular weight of from 8,000 to 15,000 and a softening point of from 110.degree. C. to 130.degree. C., and which is substantially free from an ingredient insoluble in tetrahydrofuran, and the charge controlling agent comprising a metal complex salt compound represented by the following formula (1): ##STR1## wherein M represents a metal element selected from the group consisting of zinc, iron, nickel and cobalt, and R.sup.1 and R.sup.2 each represents a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms.

Abstract: A process for the preparation of branched thermoplastic resins comprising: heating a mixture of an unsaturated resin, a free radical initiator, and a stable free radical agent; adding to the heated mixture at least on polymerizable monomer; and cooling the mixture, wherein the resulting product is a branched thermoplastic resin with arms or branches comprised of polymerized monomer with substantially uniform length and narrow polydispersity.

Abstract: A negatively electrifiable, non-magnetic and single component developer comprising a binder resin, a carbon black and a charge control agent, wherein the carbon black has an average primary particle diameter of 20 to 50 nm and a pH of 2 to 5, and the charge control agent comprises a compound represented by the following formula: ##STR1## wherein M represents a metal atom selected from the group consisting of zinc, iron, nickel and cobalt, and R.sub.1 and R.sub.2 each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. An image forming process using the developer is also disclosed. This one-component developer, which is suitable for use as a black toner in color image formation, can be stably charged and transported over long to give images free from fogging and having evenness of density and hardly poses problems such as dirts and color mixing over long.

Abstract: A magnetic toner comprising a binder resin a magnetic substance is disclosed, the toner containing from 2 to 20% by weight of a polyolefin, preferably polyethylene, having a dispersed particle size of from 0.01 to 0.5 .mu.m. The particle size distribution of the polyolefin preferably has a coefficient of variation of from 20 to 40%. The magnetic toner is fixable with low heat energy, hardly causes offset and smudge, and has a reduced abrasive action on a photoreceptor. It is therefore suitable for use in a fixing means with no cleaning mechanism, a machine with a double side copying function, or an organic photoreceptor.

Abstract: A magnetic toner comprising a binder resin, a magnetic substance, and polyolefin fine particles, wherein the content of the magnetic substance is from 20 to 80% by weight, the polyolefin fine particles have a mean dispersed particle diameter of from 0.01 to 0.5 .mu.m, the content of the polyolefin fine particles is from 2 to 20% by weight, and the toner particles have a residual magnetization (.sigma..sub.r) of from 4 to 7.0 emu/g. The magnetic toner has suitability both to printing and to reading with an MICR.