Eastman-kodak Company

Heidelberger Druckmaschinen Ag

The Goodyear & Tire Rubber Company

Thomas A Jadwin

Eric C Stelter

John C Wilson

Robert D Fields

Dinesh Tyagi

Peter S Alexandrovich

John F Crichton

Lawrence P DeMejo

Joseph Y Kaukeinen

Stewart H Merrill

Paul L Nielsen

Robert C Storey

Donald Saul Rimai

William B Vreeland

Gary Lee Burroway

Joseph E Guth

Edward T Miskinis

Hans G Ling

Hans W Osterhoudt

Bijay S Saha

Steven M Bonser

Thomas J Foster

Donald MacArthur Burness

John M Spence

Ravi Khanna

Edmond S Perry

James William Consaul

Thomas Karl Dykstra

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

A binder polymer composition for electrostatographic toners comprises a carboxysubstituted precursor polymer crosslinked by reaction with an N,N,N'N&#x2032;-tetrakis(2-hydroxyalkyl) bisamide compound of the structure

Crosslinked binder polymers for electrostatographic toners and toners formed therefrom

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

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

There is provided a toner composition which comprises a binder and a colorant, wherein said binder comprises

Toner compositions including polymer binders with adhesion promoting and

An electrostatic image on an image member already containing a loose dry first toner image is toned with a second toner, for example, a toner of a second and different color from the first toner image. The toning is accomplished by a developer having a high coercivity permanently magnetized carrier and toner which is moved through a development zone by a rapidly rotating core inside a sleeve on which the developer moves. Pole transitions caused by the rapidly moving core make the high coercivity permanently magnetized carrier move vigorously in a wave motion having alternating crests and troughs. Scavenging of the first toner image is prevented by separating the sleeve from the image member sufficiently that the crests of the developer do not touch the image member during the toning process. An alternating electrical field is applied between the sleeve and the image member to enhance development.

Image forming method and apparatus

A two component electrophotographic developer and development method. The developer includes carrier particles and toner comprising: polymeric binder; a first agent selected from the group consisting of compounds having the general structure: ##STR1## wherein n is from about 7 to about 21; R.sup.1 and R.sup.2 are each independently H or alkyl having from 1 to about 3 carbons; T represents an unshared electron pair or a proton and a counterion; and R.sup.3 is substituted or unsubstituted alkyl, alkylamide, aryl, or heteroaryl; and a second agent comprising quaternary ammonium salt.

Two component electrophotographic developers and preparation method

New electrostatic toners and developers are provided containing new colorless charge-control agents comprising acyloxy-t-alkylated benzoic acids.

Toner and developer containing acyloxy-t-alkylated benzoic acids as

An electrostatic latent image on a photoconductor of an electrophotographic device is developed by a gray scale monocomponent nonmagnetic development system using a combination of AC and DC bias voltages applied to a developer roller and a monocomponent nonmagnetic developer applied to the developer roller by an adder roller. The developer comprises a mixture of toner particles charged to one polarity and transparent beads charged to the opposite polarity, by triboelectric charging in bulk in an alternating field between the two rollers, rather than by friction contact with apparatus surfaces. The adder roller applies the charged mixture to the developer roller for developing the latent image in an electric field to an image density determined by the magnitude of the DC bias. A DC bias may be applied to the adder roller, especially to provide a gradient relative to the DC component of the developer roller bias for driving the bulk charged mixture onto the developer roller. A doctor blade is usable to smooth the toner into a selective thickness layer on the developer roller. The developer roller may have an uncoated semiconductive surface layer, or one covered by a non-conductive coating. The system provides greater uniformity of triboelectrical charging and reduced sensitivity to surface contamination.

Gray scale monocomponent nonmagnetic development system

Disclosed are two-phase glass composite carrier particles which comprise a composite of a magnetically hard ferrite material having a single phase hexagonal crystalline structure of the formula MO.6Fe.sub.2 O.sub.3 where M is barium, strontium or lead exhibiting a coercivity of at least 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 20 EMU/gm when in an applied field of 1000 Oersteds which is dispersed in a glass matrix comprised of from about 10 to 20 molar percent CuO, from about 10 to 40 molar percent BaO and from about 10 to 40 molar percent B.sub.2 O.sub.3 ; or a glass matrix comprised of from about 10 to 20 molar percent of V.sub.2 O.sub.5, from about 10 to 40 molar percent BaO and from about 10 to 40 molar percent B.sub.2 O.sub.3. Also disclosed is an electrostatic two-phase dry developer composition comprising charged toner particles mixed with oppositely charged carrier particles as described above. A method of developing an electrostatic image by contacting the image with the two-phase dry developer composition also is disclosed. The developer compositions of the invention exhibit reduced toner throw-off and other disclosed advantages.

Glass composite magnetic carrier particles

New polyesters are provided, having advantageous utility as dual function binder/charge agents in electrostatographic toner particles. The new polyesters contain a quaternary phosphonium salt comprising a cationic portion and an anionic portion, wherein the cationic portion comprises a phosphonium atom directly covalently bonded to at least one aryl moiety substituted with a group containing an ester linkage to the rest of the polyester, and wherein the anionic portion of the salt comprises an arylsulfonate moiety in which the aryl group is unsubstituted or is substituted with one or more alkyl, halide, or group having an ester linkage to the rest of the polyester.

Polyesters containing covalently bound quaternary phosphonium salts

New electrostatographic toners and developers are provided, containing dual function polyester binder/charge agents. The new toner particle has an average diameter in the range of 0.01 to 100 micrometers and comprises a binder polyester and a charge-control agent comprising a quaternary phosphonium salt, wherein the phosphonium salt has a cationic portion comprising a phosphorus atom covalently bonded to at least one moiety containing an ester linkage to the binder polyester.

Growing community of inventors

Rochester, NY, United States of America

Thomas A Jadwin