Am International Incorporated

Addressograph Multigraph Corporation

Virgil W Westdale

James L Hanrahan

John Novotny

Charles A Kumins

Pabitra Datta

John Novotny, Jr

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 comprising a 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 toner includes a magnetic oxide component in a range of from 50 to 65 percent by weight and a polyamide resinous component in a range of from 50 to 35 percent by weight.

Pressure fixing a single component toner with polyamide-rosin

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.

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

A single component electrophotographic developer composition is disclosed comprising a low melt viscosity polyamide resin and a magnetic oxide component of such particle size as to greatly enhance the development of low background high density images. Highly conductive carbon may be added to control the resistivity of the developer particles.

Heat fusible single component toner having a polyamide binder

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.

Method of preparing a lithographic printing master

A magnetic toner developing system has a hopper feeding magnetic toner to a magnetic roller brush positioned over a non-magnetic guide that supports a sheet in its passage through a development zone. A plurality of magnets are mounted beneath the guide and restrain any toner on the underside of the sheet from being carried away from the development zone. The stronger magnetic field of the developer brush attracts the restrained toner as the sheet is transported out of the development zone.

Magnetic toner retainer means

A pressure fixable toner for electrostatic image development, which can be fixed upon a receiving member by pressure, is formulated with a high density, low molecular weight polyolefin, one or more coloring agents, and optionally, other adjuvants.

Polyethylene pressure fixable electroscopic printing powder and pressure

Carrier particles for use in an electrophotographic process are prepared by coating the surface of the carrier particles with a perfluoro carboxylic acid in a polymeric binder. The resulting carriers are long lived and capable of imparting a positive triboelectric charge to electroscopic powders mixed therewith.

Coated carrier particles for use in electrophotographic process

A dry electrostatic developer mix having improved fatigue-resistance properties, is realized by adding to the developer mix, which contains carrier particles and pigmented toner particles, molybdenum disulfide in amounts ranging from about 0.005% to about 1.0% preferably in the range of from about 0.009% to about 0.2% based on the weight of carrier particles present in the developer mixture.

Electrostatic developer mix containing either MoS.sub.2, TiS.sub.2, WS.sub.

A method of making a reproduction of a graphic original using high output electrostatic reproduction equipment which utilizes photoconductive members that are each developed in sequence using a developer mix and wherein the longevity of said developer mix is affected by the stress to which it is subjected in the environment of said high output equipment, said method comprising the steps of:

Method for making reproductions of a graphic original from a high output

Carrier particles for use in an electrophotographic process are prepared by applying a mixture of a perfluoro acid and molybdenum disulfide to the surface of the carrier particle. The resulting carriers have a very thin and effective film deposited on the surface thereof and are long lived and abrasion resistant.

Treated carrier particles used in electrophotographic process

Chemically treated carrier particles for use in electrophotography

Carrier particles for use in an electrophotographic process are prepared by applying a mixture of a perfluoro acid and polyvinylidene fluoride to the surface of the carrier particle. The resulting carriers are long lived, abrasion resistant and capable of imparting a high triboelectric charge to electroscopic powders mixed therewith.

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Barrington, IL, United States of America

Virgil W Westdale