Abstract: This invention is generally directed to magnetic toners comprised of a styrene butadiene copolymer resin, and a cubically shaped magnetite material, which toners have a fusing latitude range of at least 30 degrees Fahrenheit up to a maximum temperature of 390 degrees Fahrenheit. Toners having melt fusing temperatures of from about 300 degrees Fahrenheit to about 375 degrees Fahrenheit are desirable. The preferred cubical magnetite used is Mapico Black, which is present in amounts of from about 40 percent to about 70 percent. The toners of the present invention are useful for example in magnetic imaging systems, especially systems employing heat pressure fusing and high speed fusing systems.

Abstract: An electrostatographic development and cleaning system employing conductive carrier particles. The carrier particles comprise a core having magnetic or magnetically-attractable properties which is coated with a polymer to provide particles having a resistivity of less than about 10.sup.10 ohm-cm. The carrier particles also provide efficient removal of residual toner deposits from a photoreceptor surface after a copying operation.

Abstract: Disclosed is a positively charged toner composition comprised of a resin, a colorant and polymers of vinyl pyrrolidone of the formula: ##STR1## wherein x is a number of from about 20 to 1,800 and y is zero, or 1. A developer material is typically formulated by adding a carrier to the toner composition. Images of high quality are obtained when using these developers in an electrophotographic imaging system. The polymers of vinyl pyrrolidone are also useful as dispersants.

Abstract: This invention is directed to new electrophotographic, and magnetic toners, which are useful for example in high speed fusing systems, these toners being comprised of a polyamide resin, a pigment or colorant, which pigment or colorant may be magnetic and as an optional ingredient, a carrier material. The polyamide resin is of the formula ##STR1## wherein R, R.sub.1, R.sub.2, and R.sub.3 are radicals independently selected from aliphatic, substituted aliphatic, aromatic, substituted aromatic, cycloaliphatic, and heterocyclic, x is a number of from 1 to about 100, and y is a number of from 1 to about 100. In one preferred embodiment the toner composition is comprised of the polyamide resin and a high loading, 50-75 percent of a magnetic material, allowing for high speed fusing in magnetic imaging systems.

Abstract: There is described an electrophotographic imaging method which utilizes an imaging member comprising a substrate, a layer of a charge carrier injecting material, a layer of a charge carrier transport material, a layer of a photoconductive charge carrier generating material and an electrically insulating overcoating layer. In operation, the member is charged a first time with electrostatic charges of a first polarity, charged a second time with electrostatic charges of a polarity opposite to said first polarity in order to substantially neutralize the charges residing on the electrically insulating surface of the member and exposed to an imagewise pattern of activating electromagnetic radiation whereby an electrostatic latent image is formed. The electrostatic latent image may be developed to form a visible image which may be transferred to a receiver member. Subsequently the imaging member may be reused to form additional reproductions after erasure and cleaning steps are carried out.