Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by impregnating low density imbibitive polymer particles with magnetic or magnetically attractable metal or metal oxide. The low density magnetic composite carrier particles are prepared by the solution phase thermal decomposition of transition metal carbonyls in the presence of the polymer particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with stirring so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon the polymer particles are impregnated within their pores with elemental metal. The mixture is cooled, the beads washed, air dried, and recovered.

Abstract: Electrostatographic carrier materials having low bulk densities and high magnetic permeabilities are obtained by impregnating low density imbibitive polymer particles with magnetic or magnetically attractable metal, or metal oxide. The low density magnetic composite carrier particles are prepared by the solution phase thermal decomposition of transition metal carbonyls in the presence of the polymer particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with stirring so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon the polymer particles are impregnated within their pores with elemental metal. The mixture is cooled, the beads washed, air dried, and recovered.

Abstract: Transparent colored materials having low bulk densities and high magnetic permeabilities are obtained by encasing silicaceous particles in a sheath of magnetic or magnetically-attractable metal, which are then heat-treated. The magnetic composite particles are prepared by the solution phase thermal decomposition of transition metal carbonyls in the presence of the silicaceous particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with agitation so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon coating of the silicaceous particles with elemental metal is complete. The mixture is cooled, the beads washed, air-dried, and recovered. The metal coated particles are then heated in an ambient atmosphere for between about 2 to about 120 minutes at a temperature of from between about 50.degree. C. and 700.degree. C.

Abstract: Transparent colored materials having low bulk densities and high magnetic permeabilities are obtained by encasing silicaceous particles in a sheath of magnetic or magnetically-attractable metal, which are then heat-treated. The magnetic composite particles are prepared by the solution phase thermal decomposition of transition metal carbonyls in the presence of the silicaceous particles with a suitable suspending medium. Air and moisture are excluded from the reaction vessel and the contents are heated with agitation so that the carbonyl boils and the mixture is refluxed until the temperature rises to that of the suspending medium whereupon coating of the silicaceous particles with elemental metal is complete. The mixture is cooled, the beads washed, air-dried, and recovered. The metal coated particles are then heated in an ambient atmosphere for between about 2 to about 120 minutes at a temperature of from between about 50.degree. C. and 700.degree. C.