Emulsion polymerization process for dry positive toner compositions employs charge control agent as wetting agent
AssigneeXerox Corporation
InventorsChristopher J. AuClair, Chin H. Lu
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AssigneeXerox Corporation
InventorsChristopher J. AuClair, Chin H. Lu
Estimating the term…
This invention relates to a process for the preparation of dry positively charged toner particles, and more spceifically a polymerization process for preparing dry positively charged toner resins, containing a charge control agent, or additive which has a dual function, as a wetting agent in the polymerization process, and as a charge control agent for the toner resin, whereby the charge control agent is firmly bonded (attached) to the toner resin and is uniformly dispersed in the resin, or emulsion polymerization of a monomer material, a pigment and a charge control additive. As a result of the polymerization there is formed a dry positively charged toner resin which has attached thereto the charge control agent.
A process for preparing dry positively charged toner particles which comprises subjecting to an emulsion polymerization, or suspension polymerization in the absence of a surfactant, a toner resin and colorant, the resin being a styrene/n-butyl methacrylate copolymer, or a styrene butadiene copolymer, carbon black, and a charge control agent present in the amount of from 0.1% to about 10 weight %, the charge control agent being selected from cetyl benzyl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride or cetyl pyridinium chloride, which charge control agent functions as a wetting agent in the polymerization process, and as a charge control agent for the toner resin, said charge control agent being permanently attached to the toner resin and uniformily dispersed in said resin thereby resulting in a toner composition having a positive uniform triboelectrostatic charge over a substantial period of time, improved particle to particle uniformity, a narrow charge distribution, and the substantial elimination of the leaching of the charge control agent from the toner resin the reaction being accomplished at a temperature of at least 50.degree. C.
Dependencies are inferred from the claim text.