Eastman-kodak Company

Nexpress Solutions, Inc.

James Hunter Anderson

Douglas E Bugner

Dinesh Tyagi

Peter S Alexandrovich

Lawrence P DeMejo

Robert A Guistina

William K Goebel

Matthew C Ezenyilimba

Dennis E DeMeyer

Donald Saul Rimai

John C Wilson

Richard C Sutton

Patrick M Lambert

Jan Bares

Robert D Fields

Bijay S Saha

Donna A DiPrima

Lawrence P De Mejo

A method of producing a custom color particulate toner for use in a two-component developer by mixing two or more component color toners. The component color toners are each surface treated with a blend of two or more types of silica particles, which differ in the functional groups appended to them. The silica blend for each component color toner is chosen so that, when the component color toners are mixed together to form the custom color mixture, they will all tribocharge to the same charge-to-mass ratio when mixed with a carrier to form a developer.

Method of producing a custom color toner

Toners and developers are disclosed. The toner of the present invention contains at least one toner resin, at least one charge control agent, at least one surface treatment agent, and optionally at least one release agent and/or colorant. The toners of the present invention have excellent triboelectric stability over a wide range of temperatures and relative humidity environmental conditions. Further, the toners of the present invention have excellent charge to mass stability over long periods of time. Development systems and methods for developing electrostatic images with toner are further disclosed.

Electrophotographic toner and development process with improved charge to mass stability

Development systems and methods for developing using chemically prepared toners are disclosed. The present invention further discloses developers used in development systems. The use of chemically prepared toners with hard magnetic carrier particles with a non-magnetic, cylindrical shell for transporting developers provides excellent benefits with respect to image quality by reducing granularity and by providing a typically constant, stable developer life as shown by the consistent level of charge to mass over time during operation.

Electrophotographic toner and development process using chemically prepared toner

There is provided a carrier, for an electrcostatographic developer, comprising particles of a hard magnetic ferrite material as the core, the core having a coating of a polymer resin, said resin in turn having a coating of an organic conductive material. The organic conductive material can be a charge control agent and can be present in very small amounts. The developer compositions have no need for preconditioning since they have stable charging characteristics. Further, they exhibit low levels of &ldquo;dusting&rdquo;.

Hard carrier particles coated with a polymer resin and a conductive material

A method of developing electrostatic images with a two component developer avoids the break-in period of developer by providing a fresh mixture of carrier and toner, which toner has a first particle size but replenishes the mixture in use with toner having a second particle size larger than the first particle size. This compensates for the tendency of electrostatic images to preferentially attract the larger particles in a toner mixture.

Method of developing electrostatic images

A method for converting .alpha.-phase poly(vinylidene fluoride) to .beta.-phase poly(vinylidene fluoride), for preparing electrostatographic carrier and, electrostatographic developer and carrier. In the method for preparing electrostatographic carrier, uncoated electrostatographic carrier particles are coated with .alpha.-phase poly(vinylidene fluoride) to provide .alpha.-phase poly(vinylidene fluoride) coated carrier particles. A measurable portion of the .alpha.-phase poly(vinylidene fluoride) is then converted to .beta.-phase poly(vinylidene fluoride) by subjecting the .alpha.-phase poly(vinylidene fluoride) to a series of viscoelastic collisions having a total energy of from about 5.times.10.sup.4 to about 5.times.10.sup.5 Joules/kilogram of poly(vinylidene fluoride).

Stabilized carriers with .beta. phase poly(vinylidenefluoride)

A method of manufacturing improved strontium or barium ferrite carrier particles for use in two-component electrographic developer compositions for the development of electrostatic charge patterns is provided in which the tendency toward early life dusting of the strontium or barium ferrites is reduced. Such strontium or barium ferrite carrier particles are obtained by (i) mixing unreacted particles of iron oxide and barium or strontium oxide or, alternatively, a salt of barium or strontium convertible to the corresponding oxide by heat upon subsequent firing in a mole ratio of iron oxide to the metal oxide or salt of exactly 5.95 to 6.0:1 with an organic binder and a polar solvent, preferably water, to form a slurry, (ii) spray drying the slurry to obtain green beads of substantially uniform particle size and substantially spherical shape, and (iii) firing the beads at a temperature of from 1150.degree. to 1175.degree. C. for 10 hours to form magnetic strontium or barium ferrite carrier particles of substantially uniform particle size and substantially spherical shape having a reduced tendency towards early life dusting.

Low dusting carriers

New electrostatographic toners and developers are provided containing new charge-control agents comprising quaternary ammonium salts having the structure ##STR1## wherein R is alkyl having 12 to 18 carbon atoms.

New electrostatographic toners and developers containing new

New electrostatographic developers are provided, containing dual function polymeric binder/charge agents. The new developers contain toner particles comprising a vinyl addition binder polymer containing a quaternary phosphonium salt, wherein the phosphonium salt has an anionic portion covalently bonded to the binder polymer.

Dry electrostatographic developer containing toner particles comprising

New electrostatographic developers are provided, containing dual function polymeric binder/charge agents. The new developers contain toner particles comprising a vinyl addition binder polymer containing a quaternary phosphonium salt, wherein the phosphonium salt has a cationic portion comprising a phosphorus atom covalently bonded to the binder polymer.

New quaternary ammonium salts are provided having advantageous utility as charge agents in electrostatographic toners and developers. The salts have the structure ##STR1## wherein R is alkyl having 12 to 18 carbon atoms.

New quaternary ammonium salts

Electrostatographic toners and developers containing charge-control

New quaternary ammonium salts are provided having advantageous utility as charge agents in electrostatographic toners and developers. The salts have the structure. ##STR1## wherein R is alkyl having 12 to 18 carbon atoms.

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Rochester, NY, United States of America

James Hunter Anderson