Abstract: Disclosed is a thermally stable liquid negative developer comprising an organic liquid carrier, a pigment, a stabilizing gel on the borderline of solubility in the carrier, a latex which imparts a fixative function to the developer, and a two component charge control agent. The charge control agent consists of a first polymer, soluble in the carrier, having a basic character because of the inclusion of pyrrolidone or hydroxylated alkyl groups, and a second polymer, insoluble or on the borderline of solubility in the carrier, having an acid character because of the inclusion of free halogenated groups, and containing a minor amount of carrier soluble moieties. The two components may constitute separate ingredients, or either or both components may be incorporated into the structure of other developer components. Thus, the basic component may be included in the gel, and the acid component included in the latex.

Abstract: Disclosed is a developer composition which has improved depletion characteristics. The developer comprises an organic carrier containing latex particles comprising a major amount of a C.sub.1 -C.sub.6 lower alkyl acrylate or methacrylate polymer, a pigment system, a charge control agent consisting of a copolymer of C.sub.2 -C.sub.6 lower alkyl vinyl ether and a vinyl chloride, and an acrylic polymer gel for stabilizing the dispersion. The developer may be used in conventional copying equipment to make greater than about 20,000 copies of acceptable image density.

Abstract: Disclosed is a developer composition which in use exhibits improved depletion characteristics and produces copies of high image density. The developer comprises an organic carrier containing a pigment system, a charge control agent, and a "gelatex" which acts as a fixitive and a dispersant. The gelatex comprises a carrier-insoluble vinyl polymer and a multiply-branched, vinyl polymer which physically entraps or entangles the carrier-insoluble polymer and is on the borderline of solubility in the carrier. The gelatex component is present in the carrier as a stable dispersion and is substantially uniformly depleted as multiple copies are produced, resulting in a significantly reduced rate of image density deterioration as multiple copies are produced.