Coated carrier particles

A process for the preparation of a carrier which comprises (1) mixing carrier core with a mixture of a first and second polymer, and wherein satd first polymer contains a conductive component, different from copper iodide and said second polymer contains cuprous iodide in an amount of from about 80 to about 95 weight percent;

• (2) dry mixing the resulting carrier core for a sufficient period of time enabling the polymers to adhere to the carrier core;
• (3) subsequently heating the mixture of carrier core particles and polymer to a temperature of between about 200.degree. F. and about 550.degree. F., whereby the polymers melt and fuse to the carrier core;
• and (4) thereafter cooling the resulting coated carrier particles.

An improved process for the preparation of carrier particles with an extended triboelectric charging range and with an extended conductivity range, which process comprises mixing a carrier core with a polymer mixture, and which mixture comprises a first and second polymer having dispersed therein, respectively, carbon black and cuprous iodide, followed by heating until the polymers fused to the core, and thereafter cooling, and wherein said carbon black is present in an amount of from about 18 to about 50 weight percent, and said cuprous iodide is present in an amount of from about 80 to about 95 weight percent, and wherein said first polymer is polymethacrylate.

A carrier consisting of a core end thereover a mixture of first and second polymers, and wherein said first polymer contains a conductive component different from copper iodide and said second polymer contains copper iodide, and wherein said copper iodide is present in an amount of about 80 to about 90 weight percent and the conductivity of the resulting carrier is from about 10.sup.-10 to about 10.sup.-7 (ohm-om).sup.-1.