摘要:
An electrostatographic printer has a process unit adapted to be removably mounted in a main assembly of an electrostatographic reproducing machine, the process unit including a developement apparatus at which an electrostatic latent image is developed on an imaging member, and a transfer device which causes a developed toner image to be transferred from the moving imaging member to a copy sheet. The development apparatus is contained within a housing of an electrically insulating material, and comprises conductive means adjacent the exit portion of the development apparatus, i.e. the portion from which the imaging member emerges as it moves towards the transfer device. The conductive means includes a conductive coating on the exit portion of the developer housing, and a conductive seal member through which an electrical discharge path is provided. This reduces the tendency of debris to accumulate in the region of the exit portion, and prevents any debris which does accumulate from building up a charge (which would have detrimental effects on the developed image).
摘要:
Disclosed is a developer composition which consists essentially of a toner consisting essentially of a resin, a colorant, and colloidal silica external additive particles and a carrier consisting essentially of a core, an optional coating on the core, and an external additive selected from the group consisting of metal salts of fatty acids, linear polymeric alcohols comprising a fully saturated hydrocarbon backbone with at least about 80 percent of the polymeric chains terminated at one chain end with a hydroxyl group, polyethylene waxes with a molecular weight of from about 300 to about 2,000 polypropylene waxes with a molecular weight of from about 300 to about 3,000, and mixtures thereof. Also disclosed are processes for using the aforementioned developer in a tri-level development process.
摘要:
A process for crosslinking an image comprising applying ultraviolet light to an image comprised of a toner containing an unsaturated resin and colorant.
摘要:
A toner composition comprised of binder, colorant, and a surface additive of a coated silica and wherein said silica possesses a BET surface area, in m2/g of from about 35 to about 65, a bulk density, in grams/liter, of from about 40 to about 60, and wherein the size diameter determined from the BET measurement is from about 20 to about 100 nanometers.
摘要:
A toner of toner particles containing at least one binder, at least one colorant, and preferably one or more external additives is advantageously formed into a developer and used in a magnetic brush development system to achieve consistent, high quality copy images. The toner particles, following triboelectric contact with carrier particles, exhibit a charge per particle diameter (Q/D) of from 0.6 to 0.9 fC/&mgr;m and a triboelectric charge of from 20 to 25 &mgr;C/g. The toner particles preferably have an average particle diameter of from 7.8 to 8.3 microns. The toner is combined with carrier particles to achieve a developer, the carrier particles preferably having an average diameter of from 45 to 55 microns and including a core of ferrite substantially free of copper and zinc coated with a coating comprising a polyvinylidenefluoride polymer or copolymer and a polymethyl methacrylate polymer or copolymer.
摘要:
A process for preparing an electrophotographic toner composition which comprises premixing a pigment and a charge control additive in the absence of a solvent, subsequently admixing the premixed pigment and charge control additive and a resin, and extruding the pigment, charge control additive, and resin. The pigment and the charge control additive may be premixed prior to being added to the extruder with the resin; alternatively, the pigment and charge control additive may be premixed by adding them to the extruder via an upstream supply means and extruding them, and subsequently adding the resin to the extruder via a downstream supply means.
摘要:
At least three differently colored toners, designed for use together in forming a color image in an image developing device, have substantially the same melt flow index value. By substantially matching the melt flow index values of at least three toners of a set of toners, it has been found that the resultant color image has an overall excellent image quality, i.e., an excellent overall gloss level without any gloss banding. The toners may be made to have substantially the same melt flow index value in a carefully controlled process that includes forming a single toner by feeding at least one binder and at least one colorant into a mixing device to form a mixture, upon exit of the mixture from the mixing device, measuring a rheology property of the mixture with at least one monitoring device, and comparing the measured rheology property to a target property range that the measured rheology property must be within in order for the single toner to achieve the desired melt flow index value, wherein if the measuring indicates that the rheology property is outside of the target property range, feed amounts of the at least one binder or of the at least one colorant into the mixing device are adjusted, grinding the mixture, optionally together with a portion of one or more external additives to be added to the mixture, classifying the ground mixture, mixing the classified mixture with one or more external surface additives to obtain the single toner having the desired melt flow index value, and repeating the steps for each additional differently colored toner.
摘要:
An apparatus and method for determining both the breakdown voltage and the conductivity of a particulate material, such as a developer material, is provided. In a preferred embodiment, the apparatus for determining breakdown voltage comprises a breakdown cell for storing a preselected quantity of the particulate material and a voltage breakdown ("VB") autometer, the VB autometer being adapted to apply a first voltage across at least portions of the preselected quantity of the particulate material. The VB autometer is capable of progressively varying the magnitude of the first voltage. A measuring circuit, for measuring a second voltage, is coupled to the voltage breakdown cell. When the second voltage substantially equals a preselected reference voltage, the first voltage substantially equals the breakdown voltage of the particulate material.
摘要:
A printing machine of the type including an image receiving member having a charge retentive surface with a first developed image being disposed in a first zone and a second developed image being disposed in a second zone is provided. The printing machine preferably including a corona generator positioned adjacent the charge retentive surface and characterized by an electrical parameter; a first control device for setting the electrical parameter to a first level for disposing the first developed image at a first charge level as the first developed image is passed by the corona generator; a second control device for changing the electrical parameter to a second level for disposing the second developed image at a second charge level as the second developed image is passed by the corona generator; and a cleaning member, contacting the charge retentive surface, for substantially removing both the first developed image and a portion of the second developed image from the the charge retentive surface, wherein the capacity of the cleaning member to remove the first developed image and the portion of the second developed image from the charge retentive surface depends on the magnitudes of the first and second levels.