Lexmark International, Inc.

Rick Owen Jones

Ligia Aura Bejat

Jing X Sun

Cory Nathan Hammond

Kasturi Rangan Srinivasan

Michael James Bensing

John Joseph Kraseski

Danielle Renee Ashley

Ashley Schafer Grant

James Craig Minor

George P Marshall

Michael Anthony Blassingame

Brandon Michael Lin

Robert Watson McAlpine

John Melvin Olson

Courtney Harrison Soale

John Joseph Earley

Michael G Miller

Peter Nikolaivich Yaron

David Brian Bilbrey

Devon Jean Vaccaro Strain

Claudia Alexandra Marin Goggin

The toner composition of the present invention and method to make the same includes toner particles mixed with a specific set of extra particulate additives including large colloidal silica sized 90 nm to 120 nm and having a conductivity of less than 20 &#x3bc;s/cm in combination with medium size silica particles sized 30 nm to 60 nm. Optionally, additional extra particular additives such as silica sized 2 nm to 20 nm, alumina, titania or mixtures thereof can be used. The finished toner having these specific additives exhibited superior printing performance.

Toner compositions including silica blends and method to make the same

A chemically prepared toner composition according to one example embodiment includes a core including a first polymer binder, a colorant and a release agent; a shell that is formed around the core that includes a second polymer binder; and a borax coupling agent between the core and the shell and an alkoxysilane hydrocarbon or combination of different alkoxysilane hydrocarbons that are bonded to the outer surface of the shell using a hydrolytic deposition process. This successful alkoxysilane hydrocarbon surface treatment on the outer surface of the toner particle results in attaining a desirable charge stability in hot and humid environments and ultimately improving the quality of the toner, especially by reducing toner dusting, toner fuming and ultra-fine particles generation.

Toner formulation having a silane surface treated on its outer surface and method of preparing the same

A method for producing core shell toner for electrophotography according to one embodiment, includes surface treating the outer surface of a core shell toner particle with a alkoxysilane hydrocarbon or combination of different alkoxysilane hydrocarbons using a hydrolytic deposition process after the core shell toner particle is fully formed. This method results in the bonding of the alkoxysilane hydrocarbon or combination of different alkoxysilane hydrocarbons to the outer surface of the core shell toner particle. In an alternative method, the outer surface of the toner is surface treated with the alkoxysilane hydrocarbon solution and then fused to form toner particles. The alkoxysilane hydrocarbon surface treated core shell toner also can be mixed with magnetic carrier beads to form a developer mix to be used in a dual component development electrophotographic printer.

A chemically prepared toner composition according to one example embodiment includes a core including at least one polymer binder, a colorant and a release agent; a shell that is formed around the core and includes a third polymer binder; and a borax coupling agent between the core and the shell. The binder for the shell is a styrene acrylic polyester copolymer having a glass transition temperature (Tg) between 55&#xb0; C. to 65&#xb0; C., a melt temperature (Tm) between 100&#xb0; C. to 130&#xb0; C., a peak molecular weight of about 12,000 and acid value from 10-28.

Chemically prepared core shell toner formulation including a styrene acrylate polyester copolymer used for the shell

A developer mix formulation having tribocharge uniformity across varying temperature and humidity conditions is provided. A developer mix used in a dual component development (DCD) system is a mixture of toner particles and magnetic carrier particles. Tribocharge uniformity is achieved in the developer mix by using magnetic carrier particles having surface additives on its surface. Surface additives include but are not limited to silica, titania and alumina.

Formulation for a developer mix having tribocharge uniformity across different temperature and humidity conditions

A method for providing a developer mix having tribocharge uniformity across varying temperature and humidity conditions is provided. A developer mix used in a dual component development (DCD) system typically is a mixture of toner particles and magnetic carrier particles. Tribocharge uniformity is achieved in the developer mix by performing the step of treating the surface of the magnetic carrier particles with surface additives before the magnetic carrier particles are mixed with the toner particles. Surface additives include but are not limited to silica, titania and alumina.

Method to achieve tribocharge uniformity of a developer mix across different temperature and humidity conditions by modifying the surface of the magnetic carrier particle

This invention provides a toner with improved charge and charge stability by suitable addition of extra particulate additives (EPA) such as aluminum cerium oxide and/or cerium zirconium oxide. The additives may be combined with toner in a conical mixer having selected temperature control. The invention also provides toner which may provide reduced print quality defects such as ghosting or residual image and fade-to-color.

Toner having improved charge characteristics

The present invention relates to toner compositions containing extra particulate additives. The additives may include a mixture of silica particles having differing BET surface areas and may include an acicular inorganic oxide. The control of such additives may be relied upon to control toner performance with respect to functional performance considerations such as filming and/or overall print quality.

Toner formulations containing extra particulate additives

A high speed toner comprising a body of hybrid resin which is about 92 percent by weight polyester and 8 percent by weight polystyrene. Blended in the resin is a charge control agent, a pigment, and about 10 percent by weight of the toner of fumed aluminum oxide. Where the pigments are color-subtractive the charge control agent is a copolymer of styrene and 2-acrylamido-2-methylpropane sulfonic acid. The toner is mixed with a carrier of ferrite particles having a thick silicone coating to remain through the long life of the toner.

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Berthoud, CO, United States of America

Rick Owen Jones