Eastman-kodak Company

Robert C Storey

Thomas A Jadwin

James F Paxon

Dinesh Tyagi

William Yurich Fowlkes

Hans W Osterhoudt

Theodore H Morse

James R Olson

A monocomponent electrostatographic developer is disclosed. The developer contains a negative charging toner wherein the toner particle surface contains particles of cerium dioxide and a mixture of two hydrophobic silicon dioxides having a particle size of 0.005 to 0.03 .mu.m.

Monocomponent developer comprising surface treated toners

Reproduction apparatus wherein registration errors in image formation are corrected in response to an examination of enlarged reproductions of reproductions so as to make the appropriate adjustments in timing of process steps, giving a registration suitable for very high quality multiple image reproduction.

Multiple image registration

Roller transfer apparatus of simplified construction which has an extended transfer nip exhibiting low pressure for effecting efficient transfer of marking particle images from a dielectric support with a substantial reduction in image transfer defects. In such transfer apparatus, the dielectric support in the form of a web is supported by a mechanisnm offset relative to the transfer roller in an upstream and/or downstream direction to position the web relative to the transfer roller to establish an extended contact nip zone with a low nip pressure. As an example, the support mechanism includes a pair of spaced rollers respectively offset relative to the transfer roller in an upstream and downstream direction to provide a nip zone with a dimension of at least 0.01 m measured in the direction of roller rotation and a nip pressure in such zone of less than 2.times.10.sup.4 Pa.

Roller transfer apparatus having an extended nip exhibiting low pressure

Alkyldimethylbenzylammonium salts are employed as charge control agents for fusible dry electrophotographic toners.

Electrophotographic dry toner and developer compositions

A method for preparing a preconditioned dry electrographic developer comprising the steps of: a) intimately mixing together an unconsolidated mass of carrier particles, and an unconsolidated mass of resin based toner particles containing charge control agent in greater concentration than desired in the final developer, the concentration of said toner in the resulting mixture being less than desired in the final developer, such mixing being for a sufficient length of time and in such a way as to pack any pores of said carrier particles with toner, to scum the surfaces of said carrier particles with charge control agent, and to abrade the surfaces of said carrier particles; and b) introducing into and intimately mixing with said resulting mixture an additional quantity of resin based toner particles containing charge control agent in about the same concentration as desired in the free toner in the final developer, said additional quantity together with the free toner present after step (a) bringing the concentration of free toner in the final mixture up to that desired in the final developer. Mixing desirably is accomplished by tumbling in a rotating container.

Method for producing improved electrographic developer

The present invention relates to the use of low levels of certain alkoxylated amines as charge control agents for an electrostatic toner contained in dry electrographic developer compositions.

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Penfield, NY, United States of America

Robert C Storey