Abstract: Polymeric powders of small particle size and size distribution and of irregular morphology are prepared by a limited coalescence procedure wherein a polymer in an organic solvent is dispersed by high shear agitation in an aqueous phase containing colloidal stabilizer particles having opposite electrostatic charges. The organic solvent is evaporated and the polymer particles are recovered from the aqueous medium. The particles are of irregular shape and narrow particle size distribution and have superior electrostatic transfer properties when used as electrostatographic dry toners.

Abstract: There is provided a carrier, for an electrostatographic developer, comprising particles of a hard magnetic ferrite material as the core, the core having a coating of a polymer resin, said resin in turn having a coating of an organic conductive material. The organic conductive material can be a charge control agent and can be present in very small amounts. The developer compositions have no need for preconditioning since they have stable charging characteristics. Further, they exhibit low levels of “dusting”.

Abstract: A method is described for the preparation of electrostatographic toner particles which involves the surface treatment of a pigment by depositing thereon a coating of a low melting point hydrophobic semi-crystalline polyester wax.

Abstract: A method is described for the preparation of electrostatographic toner particles which involves the surface treatment of a pigment by depositing thereon a coating of an elastomeric thermoplastic polymer.

Abstract: A method is described for the preparation of electrostatographic toner particles which involves the surface treatment of a pigment by depositing thereon a coating of a low melting point wax. The method involves preparing a mixture of a wax solution and a pigment dispersion which is heated to a temperature sufficient to assure dissolution of wax and permitting the mixture to cool slowly to room temperature at which point a coating of wax is deposited upon the surface of the pigment. The wax coated pigment particles are then used as a component of the organic phase in a limited coalescence process.

Abstract: A method is described for the preparation of electrostatographic toner particles which involves the surface treatment of pigments using a low melting point highly reactive wax. The method involves preparing a melt dispersion comprising a pigment, a polymeric binder and a low melting point wax at elevated temperatures, the wax melting and coating the surface of the pigment. The melt dispersion is then used as a component of the organic phase in a limited coalescence process.

Abstract: A method of preparing polymer particles having narrow size distribution in a suspension process employing a solid colloidal stabilizing agent. The solid colloidal stabilizer is a copolymer of about 25 to about 80% by weight, based on total monomer weight, of an addition polymerizable nonionic oleophilic monomer, about 5 to about 45%, by weight, of an addition polymerizable nonionic hydrophilic monomer, about 1 to about 50% of an addition polymerizable ionic monomer, and 0 to about 20 percent, by weight, of a crosslinking monomer having at least two addition polymerizable groups. Also disclosed are polymeric particles comprising a core polymer covered by a layer of the smaller copolymer stabilizer particles and electrostatographic toners comprising such polymeric particles.

Abstract: A method of preparing polymer particles having narrow size distribution in a suspension process employing a solid colloidal stabilizing agent. The solid colloidal stabilizer is a copolymer of about 25 to about 80% by weight, based on total monomer weight, of an additional polymerizable nonionic oleophilic monomer, about 5 to about 45%, by weight, of an addition polymerizable nonionic hydrophilic monomer, about 1 to about 50% of an addition polymerizable ionic monomer, and 0 to about 20 percent, by weight, of a crosslinking monomer having at least two addition polymerizable groups. Also disclosed are polymeric particles comprising a core polymer covered by a layer of the smaller copolymer stabilizer particles and electrostatographic toners comprising such polymeric particles.