Am International Incorporated

James L Hanrahan

Virgil W Westdale

William C Anderson

A process of preparing a lithographic printing master is presented utilizing electrophotographic principles. As a result of the high density, low background images which can be developed using the disclosed novel developer composition, a high quality lithographic master can be fabricated. The novel developer comprises a low melt viscosity polyamide resin composition, a magnetic oxide component and a conductive carbon pigment.

Method of fabricating a lithographic master

A pressure fixable single component electrophotographic toner or developer composition of a particle size of from 10-40 microns comprising a specialized low melt viscosity polyamide resin composition and a magnetic oxide component. Highly conductive carbon may be added to control the resistivity of the developer particles. The developer comprises from 65.50 percent of the magnetic oxide component and from 35-50 percent of the polyamide resinous component.

Pressure fixing a single component toner with polyamide-rosin

A magnetic toner developing device for developing images on a photoconductive sheet. The device includes a magnetic developer roller brush for applying a single component toner to the sheet. An electrically isolated guide plate extends beneath the developer roller brush in close proximity thereto and supports the sheet in its travel through a development zone formed between the developer roller brush and the guide plate. The guide plate is electrically isolated from a support frame to eliminate electrostatic clamping of the sheet to the guide plate.

Magnetic toner developing device

An improved process for preparing a single component toner or developer composition is disclosed whereby toner fines are removed from the composition prior to the addition of conductive carbon followed by a reclassification step to remove excess carbon particles, i.e., those carbon particles not attached to the toner.

Method of making a single component toner

A process of preparing a lithographic printing master is presented utilizing electrophotographic principles. As a result of the high density, low background images which can be developed using the disclosed novel developer composition, a high quality lithographic master can be fabricated. The novel developer composition comprises a low melt viscosity polyamide resin, a magnetic oxide component and a conductive carbon pigment.

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Mt. Prospect, IL, United States of America

James L Hanrahan