Eastman-kodak Company

Heidelberger Druckmaschinen Ag

Other

Robert D Fields

John C Wilson

Dinesh Tyagi

Thomas A Jadwin

Eric C Stelter

John F Crichton

Satyanarayan A Srinivasan

Peter S Alexandrovich

Gretchen S McGrath

Patrick M Lambert

Robert A Guistina

James Hunter Anderson

Thomas J Foster

Paul L Nielsen

Charles T Havens

Satyanarayan A Srinivaan

The present invention is a toner that includes a polymeric binder and a polyethylene wax or ester wax. A dispersing agent of poly(ethylene vinyl acetate) is included in the toner that dispersed the wax and reduces the amount of free wax particles.

Toner composition

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

Toner particles having at least one toner resin and at least one polyalkylene wax or a wax having a percent crystallinity of 80% or more are described. The wax that is present in the toner particles has a polydispersity of 2.0 or higher or a percent crystallinity of 80% or more, and also preferably has a number average molecular weight of about 2,000 or higher and/or a melting temperature onset of from about 115&#xb0; C. to about 130&#xb0; C. Development systems using the toner particles of the present invention are further described. Also, improvements in various properties associated with development systems are further described such as reduced toner dust levels as well as improved toner image abrasion resistance.

Electrophotographic toner containing polyalkylene wax or high crystallinity wax

Toner particles are described containing at least one toner resin and at least one wax. The wax present in the toner particles has an average domain size of about 1 micron or less. Developer systems, two component and monocomponent, are further described as well development systems and methods for developing an electrostatic image.

Electrophotographic toner with uniformly dispersed wax

Development systems and methods for developing using magnetic toner are disclosed. The present invention further discloses developers used in development systems as well as the toner used in developer for magnetic ink character recognition printing. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains magnetic toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system. A method for developing electrostatic image with magnetic toner is further disclosed, for example, involving the above-described development system. Magnetic toner particles having a low magnetic loading such as on the order of 28% by weight or less, based on the weight of the toner are further described wherein these magnetic toners can include a spacing agent on the surface of the magnetic toner particles. A developer is further disclosed which contains the magnetic toner particles of the present invention with hard magnetic carrier particles. Other developer compositions are also described.

Development systems for magnetic toners and toners having reduced magnetic loadings

Development systems and methods for developing using toner are disclosed. The present invention further discloses developers used in development systems. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system. The development system of the present invention further includes a fuser roll which is coated with a silicone rubber or other low surface energy elastomer or resin. The fuser roll is preferably in a pressure contact arrangement with a backup or pressure roll. The images resulting from the development system of the present invention have an excellent combination of properties, in particular, the prints resulting from the development process of the present invention have improved image quality in combination with excellent fusing quality. A method for developing electrostatic images with toner is further disclosed, for example, involving the above-described development system.

Electrophotographic toner and development process with improved image and fusing quality

Toner formulations and developers containing the toner formulations are described. The toner contains at least one toner resin, at least one first charge control agent capable of providing a consistent level of charge, at least one second charge control agent capable of providing a sustained level of charge, at least one surface treatment agent, and at least one release agent and optionally at least one colorant. The toners of the present invention preferably provide a consistent level of charge of from about &minus;10 to about &minus;30 micro C/gm and also provide this level of charge for a sustained period of time, such as from about 2 to about 10 minutes. The toners of the present invention also provides excellent ruboff values for an image printed from the toners of the present invention. Methods of improving ruboff are described as well as methods to develop an image using the toner of the present invention.

Electrophotographic toner with stable triboelectric properties

Development systems for magnetic toners having reduced magnetic loadings

Disclosed are methods and apparatus for electrographic development which utilize a rotating magnetic core, a toner shell disposed around the rotating magnetic core, and developer compositions disposed on the toner shell which include a hard magnetic material, such as a strontium ferrite. The shell in embodiments has an outer surface with a surface roughness Ra of less than 32 microinches. The methods and apparatus do not require special manufacturing steps to place surface roughness or irregularities on the shell, and, thus, can provide the same or better image quality with relatively less complex manufacturing steps and at reduced cost.

Electrographic methods using hard magnetic carrier particles

Method of making an electrophotographic toner surface treated with metal oxide

An electrophotographic toner composition comprising toner particles admixed with metal oxide, wherein the metal oxide is selected from titanium dioxide and silicon dioxide; the metal oxide is 0.1 to 5.0 weight percent of the toner composition; and the ratio of titanium dioxide on the surface of the toner particles:total titanium dioxide in the toner composition is in the range of 1.0-3.0:1.0 and the ratio of silicon dioxide on the surface of the toner particles:total silicon dioxide in the toner composition is in the range of 10.0-25.0:1.0.

Electrophotographic toner surface treated with metal oxide

The invention, in its broader aspects provides an electrophotographic toner having polymeric binder and 2-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)acetamides as charge control agent.

2-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)acetamides negative charge control agents for electrostatographic toners and developers

An electrophotographic toner is disclosed comprising a polymeric binder and an N-[2-(1,2-benzisothiazol-3(2H)-ylidene 1,1 -dioxide)-2-cyanoacetyl]benzenesulfonamide as charge control agent having the structure: ##STR1## wherein n and X are defined in the specification. The compounds are useful as charge control agents in electrostatographic toners and developers.

N-[2-(1,2-benzisothiazol-3(2H)-ylidene

The invention, in its broader aspects provides an electrophotographic toner having polymeric binder and 2-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)acetamides as charge control agent. ##STR1## wherein n is 1 or 3; R and R.sup.1 are defined in the specification. The compounds are useful as charge-control agents in electrostatographic toners and developers.

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Rochester, NY, United States of America

Robert D Fields