Eastman-kodak Company

Alec N Mutz

Bijay S Saha

Robert E Zeman

Muhammad Aslam

Stewart H Merrill

Frederick A Stahly

Dinesh Tyagi

Kevin M Johnson

Lawrence P DeMejo

Thomas K Hilbert

James Raymond Flick

John M McCabe

Bijy S Saha

An image forming apparatus includes a source of at least one intermediate sheet which is preferably both thermally and electrically conductive. Toner images are transferred from one or more image members to the intermediate sheet under conditions of raised temperature and preferably with the assistance of an electric field. The toner image on the intermediate sheet is then overlaid with a receiving sheet and a combination of heat and pressure transfers and fuses the toner image to the receiving sheet in a single step, preferably while the sheets move at full machine speed. The sheets may then be slowed down or stopped, but are maintained together until cool at which point they are separated and the intermediate sheet fed back to the source of intermediate sheets. The image forming apparatus is particularly useful in creating multicolor toner images with small toners.

Image forming method and apparatus using an intermediate

To create an overcoat on a toner image, a clear heat softenable particulate material is applied to a fusing surface before the fusing surface contacts the toner image in a fusing nip. The particulate material softens in the fusing process and ends up as a clear overcoat for the toner image, protecting it from scratches, fingerprints, deglossing and/or softening from heat.

Method and apparatus for providing a toner image having an overcoat

A magnetic brush device for applying toner to an electrostatic image includes an applicator having a rotatable core. The sleeve for the core is made of an insulating material and preferably has a thin metallic coating on the outside of the sleeve defining the sleeve's outside surface.

Device for developing an electrostatic image on an image member

A method is provided for transferring electrostatically charged thermoplastic toner particles having a particle size less than about 8 micrometers from an element to a receiver within a transfer zone. The receiver is heated and contacted with the electrostatically charged toner particles on the element at a temperature sufficient to adhere the particles to one another at their points of contact, but insufficient to cause the toner particles to flow into a single mass. An electric field tending to force the charged toner particles toward the receiver is simultaneously applied to the transfer zone. The receiver is subsequently separated from the element.

Method of transfer of small electrostatographic toner particles

Carrier particles suitable for magnetic brush development comprising hard magnetic ferrite material having a single phase, W-type hexagonal crystalline structure represented by the formula MFe.sub.16 Me.sub.2 O.sub.27 where M is strontium or barium and Me is a divalent transition metal selected from the group consisting of nickel, cobalt, copper, zinc, manganese, magnesium, iron and mixtures thereof, exhibiting a coercivity of approximately 100 to 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 60 EMU/g when in an applied magnetic field of 1000 Oersteds are disclosed. Also disclosed are electrostatic two-component dry developer compositions comprising charged toner particles mixed with oppositely charged carrier particles comprising the magnetically hard ferrite material described above and a method of developing an electrostatic charge pattern by contacting the charge pattern with a two-component dry developer composition described above. The carrier particles provide high development efficiencies and improved image density.

Magnetic carrier particles

Small particle toner images carried on an image member are transferred to thermally conductive intermediate by heating the intermediate in the presence of an electrical field urging transfer. The intermediate is heated to a temperature sufficient to sinter the toner particles at least when they touch the intermediate and other toner particles, but insufficient to damage the image member or cause the toner to stick to the image member. The toner image is transferred from the intermediate to a receiving sheet, which step can include sufficient heat and pressure to fix the image to the receiving sheet.

Method and apparatus of transferring toner images made up of small dry

Disclosed is an interdispersed two-phase ferrite composite which comprises, as a ferromagnetic phase, a magnetically hard ferrite material having a hexagonal crystalline structure of the general formula MO.6Fe.sub.2 O.sub.3 in which M is selected from the group consisting of strontium, barium, lead and mixtures thereof exhibiting a coercivity of at least 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 20 EMU/g when in an applied magnetic field of 1000 Oersteds and, as a ferroelectric phase, a ferroelectric material comprised of at least one of the double oxides of titanium, zirconium, tin, hafnium or germanium and either an alkaline earth or lead or cadmium, in which the mole ratio of the ferromagnetic phase to the ferroelectric phase is from about 1:1 to about 1:4. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic two-component dry developer composition comprising electrically insulative charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite suitable for extremely high speed copying applications without the loss of copy image quality, and a method of developing an electrostatic image by contacting the image with a two-component dry developer composition described above.

Two phase ferroelectric-ferromagnetic composite carrier

Disclosed is an interdispersed two-phase ferrite composite which comprises, as a ferromagnetic phase, a magnetically hard ferrite material having a hexagonal crystalline structure of the general formula R.sub.x P.sub.(1-x) Fe.sub.12 O.sub.19 where R is selected from rare earth elements, P is selected from the group consisting of strontium, barium, lead, calcium and mixtures thereof and x has a value of from about 0.1 to about 0.4 exhibiting a coercivity of at least 300 Oersteds when magnetically saturated and an induced magnetic moment of at least 20 EMU/g when in an applied magnetic field of 1000 Oersteds and, as a ferroelectric phase, a ferroelectric material comprised of at least one of the double oxides of titanium, zirconium, tin, hafnium or germanium and either an alkaline earth or lead or cadmium, in which the mole ratio of the ferromagnetic phase to the ferroelectric phase is from about 1:1 to about 1:4. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic two-component dry developer composition comprising electrically insulative charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite suitable for extremely high speed copying applications without the loss of copy image quality, and a method of developing an electrostatic image by contacting the image with a two-component dry developer composition described above.

Two-phase ferroelectric-ferromagnetic composite and carrier therefrom

Disclosed is an interdispersed two-phase ferrite composite which comprises about 0.1 mole to about 1.0 mole of a spinel phase having the general formula MFe.sub.2 O.sub.4 where M is at least one element that forms a spinel ferrite and is selected from the group consisting of cobalt, manganese, iron and mixtures thereof, to about 2.5 moles of a magnetoplumbite phase having the general formula PO.6Fe.sub.2 O.sub.3, where P is selected from the group consisting of stontium, barium, calcium, lead and mixtures thereof. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic two-component dry developer composition comprising charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite, and a method of developing an electrostastic image by contacting the image with a two-component dry developer composition described above.

Interdispersed two-phase ferrite composite and electrographic magnetic

Disclosed is an interdispersed three-phase ferrite composite which comprises from about 0.1 mole to about 1.0 mole of a spinel phase having the general formula MFe.sub.2 O.sub.4 where M is at least one element that forms a spinel ferrite and is selected from the group consisting of cobalt, manganese, iron and mixtures thereof, to about 2.5 moles of a magnetoplumbite phase having the general formula PO.6Fe.sub.2 O.sub.3 where P is selected from the group consisting of strontium, barium, calcium, lead and mixtures thereof and, as a third phase, from about 0.02 to about 2.0 percent by weight, based on the combined weight of the spinel phase and the magnetoplumbite phase, of TiO.sub.2 or SiO.sub.2. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite, and a method of developing an electrostatic image by contacting the image with a two-component dry developer composition described above.

Interdispersed three-phase ferrite composite and electrographic magnetic

A negatively charged liquid electrographic developer comprising an electrically insulating carrier liquid such as a paraffinic hydrocarbon fraction, having stably dispersed therein (a) a halogenated polymer, such as chlorinated polyethylene, and having dissolved therein (b) a copolymer of a quaternary ammonium salt monomer and a solubilizing monomer and (c) a copolymer of a polar monomer and a solubilizing monomer.

Method of using liquid electrographic developers containing polymeric

Liquid electrographic developers containing polymeric quaternary salts

Liquid developers for electrography comprise an electrically insulating carrier liquid containing (1) an addition polymer comprising a polar moiety and at least one additional moiety having predetermined solubility characteristics with respect to the carrier liquid, (2) a polymer comprising a phosphonate moiety, and (3) a halogenated polymer.

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Rochester, NY, United States of America

Alec N Mutz