Abstract: Disclosed is an electrically insulating, magnetic one-component type developer comprising an electrically insulating binder medium, and a magnetic material powder and a charge control agent dispersed in the binder medium, wherein the charge control agent comprises a negative or positive charge control agent and a charge control agent having a polarity opposite to that of said charge control agent at a weight ratio of from 1/0.05 to 1/1.5.

Abstract: This is one-component type dry developer for an electrophotography which is improved on humidification ability, and consists of mixture of toner with a particle size of 5.about.50 (.mu.) and hydrophobic flow agent. The flow agent is made by covering inorganic, organic, metallic or alloy powder with thin film of non-hydrophilic synthetic resin. By using electric conductive material as core and making a range of resin film thickness so as to cause tunnel effect of electron or ion, the flow agent which has non-hydrophilic property and electric conductive property is obtained.

Abstract: Developers consisting of virtually spherical particles made by spray drying an aqueous dispersion of a magnetic substance and a coating material consisting of polymers or waxes or of a mixture of polymers with a wax and/or a plasticizer, their constituents being preferably water-dispersible, and process for their preparation.

Abstract: A photoconductive layer is produced upon a substrate by coating the substrate with a solution in an organic solvent of a polyamic acid and of 2,4,7-trinitro-9-fluorenone (TNF) and/or 2,4,5,7-tetranitro-9-fluorenone and heating the coated substrate at a temperature not exceeding 150.degree. C. to form on the substrate a polyimide coating containing the said fluorenone compound as a photosensitizer.

Abstract: A dry developing powder composition particularly suited for use in electrophotographic reproduction which comprises a magnetic toner of 35 to 50 microns in average particle size mixed with a non-magnetic toner of 5 to 30 microns in average particle size. The amount of the magnetic toner used is within the range of 85 to 98% by weight relative to the total weight of the composition and the amount of the non-magnetic toner used is within the range of 2 to 15% by weight relative to the total weight of the composition.

Abstract: A process of forming an image of toner on a latent magnetic image in a magnetic member followed by direct transfer to and coalescence on a surface to form a resist is disclosed. The surface portion not protected by the transferred resist toner image is then permanently modified by etching or plating. Chemically milled shapes are prepared as well as printed circuits and printing plates. The printed circuits may be formed by (1) etching away areas of a metal surface not protected by the resist, (2) electroless plating on areas not protected by the resist or (3) electroplating areas of a metal surface not protected by the resist, removing the resist, and in the case of (2) and (3), etching away the metal previously covered by the resist. An especially useful toner which forms a resist composition comprises a binder of thermoplastic resin and plasticizer and magnetic material present in the binder, compounded to have a tack transfer temperature of no greater than 110.degree. C.

Abstract: A magnetic brush developing system for electrostatic duplication uses a developer having a magnetic carrier and non-magnetic toner which is transferred by the brush to an electrostatic image. A analog signal is derived using a Hall sensor in contact with the brush and adjacent to a magnet of the brush. The location of the sensor after and downstream of the transfer point provides information in the signal both as to the absolute value of the concentration (ratio of toner to carrier by weight) as well as the rate of transfer of the toner to the electrostatic image. These signals are used to control the supplying of replenishment toner to the developer only when the concentration of toner drops below a predetermined desired value and then at a rate commensurate with the rate of transfer of toner to the electrostatic image.

Abstract: A particulate composite developer for electrophotography is disclosed, which has a novel dispersion structure comprising a continuous phase consisting of a homogeneous mixture of a resin and a pigment and a dispersed phase consisting of spherical particles of a soft parting or fixing material having an emulsion grade size and being dispersed in the continuous phase. This particulate developer has in combination improved adaptability to the developing operation, excellent transferring and cleaning properties, good ability to form a sharp image free of fog and good fixing property not causing an offset phenomenon.

Abstract: A reverse development is performed with application of development bias voltage to a development sleeve at the time of development, and the polarity of the bias voltage is reversed or the bias voltage is reduced to zero at the time of non-development. Furthermore, positive images and negative images can be selectively formed by changing the voltage to be applied to a charge injection electrode, without changing the bias voltage to be applied to the development sleeve.

Abstract: An image-forming method using a developer comprising as the main component ferromagnetic and insulating toner particles. Said method comprises the steps of holding said developer on a delivery member by a magnetic force, causing the developer to tuft at the developing position and to fall in contact with an electrostatic latent image-supporting member, developing the electrostatic latent image and forming a toner image by the toner particles charged predominantly by mutual friction of the toner particles, and transferring the toner image onto a plain paper superposed on the electrostatic latent image-supporting member by electrostatic transfer means. Said developer has a specific resistance of at least 10.sup.14 .OMEGA.-cm and the potential decay ratio of the developed developer is lower than 50% as measured according to the method defined in the specification.

Abstract: Electrostatic developer composition and method for developing therewith an electrostatic charge pattern of positive charge wherein the composition is free of carrier particles and consists of powder particles containing at least 80% by weight of a mixture of at least 30% by weight of: a polyester derived from fumaric acid or a mixture of at least 95 mol % fumaric acid and isophthalic acid and a polyol blend of propoxylated bisphenol characterized by the formula: ##STR1## wherein m and n are integers and added together average from 2 to 7, and at least one of (1) a copolymer of ethylene, maleic acid and/or maleic anhydride wherein from 50 to 70 mol % of ethylene repeating units are present, and (2) a wax of the group consisting of castor wax and montan wax.

Abstract: A composite magnetic developer having a self-friction-chargeability is in the form of fixable magnetic particles having a particle size of 5 to 30 microns and comprising a finely divided magnetic material dispersed in a binder medium which shows an adhesiveness under application of heat and pressure, in which the fixable magnetic particles contain fine particles of a magnetic material embedded in the surface of the fixable magnetic particles in an amount of 1 to 10% by weight based on the fixable magnetic particles and fine particles of a magnetic material adhering to the surface of the fixable magnetic particles without being embedded therein in an amount of 1 to 20% by weight based on the fixable magnetic particles. This developer provides a sharp and clear transfer image having a high density without fogging or edge effects on a transfer sheet having a low electric resistance such as a plain paper.

Abstract: Disclosed is an electrostatic photographic copying process comprising causing a substrate carrying an electrostatic latent image thereon to fall in contact with a magnetic brush of a one-component type magnetic developer to effect development of the electrostatic latent image and electrostatically transferring the formed image of the developer onto a transfer sheet, wherein a magnetic developer having an electrostatic capacity of 7.8 to 9.8 PF (picofarad) as determined under conditions of an electrode spacing of 0.65 mm, an electrode sectional area of 1.43 cm.sup.2 and an electrode load of 105 cm.sup.2 and a dielectric constant of 4 to 5 as determined under the above conditions is used as the one-component type magnetic developer.

Abstract: Magnetic toners, methods of their formation and utilization of the toners in various electrophotographic imaging systems is disclosed. The toners disclosed contain a nitrogen containing compound including, for example, amines and quaternary ammonium compounds. Toners containing such compounds are suitable for use in inductive development from a biased magnetic toner brush to an electrostatic image, and further subsequently such images may be transferred preferably by electrostatically type methods to a substrate such as plain bond paper.

Abstract: Disclosed is a one-component type magnetic developer which comprises a binder medium and 45 to 65% by weight, based on the total developer, of fine particles of a magnetic material dispersed in the binder medium, the binder medium comprising a homopolymer of an aromatic vinyl monomer or a copolymer of (a) at least one aromatic vinyl monomer with (b) at least one mono- or di-ethylenically unsaturated monomer other than the aromatic vinyl monomer and having a weight average molecular weight of 75,000 to 150,000, wherein the electrostatic capacity as determined under conditions of an electrode spacing of 0.65 mm, an electrode sectional area of 1.43 cm.sup.2 and an electrode load of 105 g/cm.sup.2 is 7.8 to 11.7 PF (picofarad), the dielectric constant is 4 to 6 as determined under the above conditions and the electric resistance is at least 5.times.10.sup.13 .OMEGA.-cm as determined under the above conditions.

Abstract: This invention relates to a single component magnetic tone containing an epoxy resin and a magnetic pigment, particularly iron oxide pigments, which have been treated with surface reactive coupling materials, selected from organic titanates and lechithin, which treatment results in a magnetic toner where the melt flow temperature of such a toner is below 110.degree. C., and preferably between about 90.degree. C. and 105.degree. C. Also described is a method for the development of magnetic images which involves causing the formation of a magnetic latent image on a magnetizable recording medium, developing the image with the above toner, followed by transferring the image to a suitable substrate, and subsequently permanently fusing the image to said substrate by heat.

Abstract: The sharpness and contrast of reversed images obtained by pressure-fixation of electrostatically developed copies of negative transparencies is provided by dissipating the electrostatic latent image after the development step but before the pressure-fixing step. The process finds application in microfilm reader/reproduction devices.

Abstract: This invention is generally directed to toner compositions comprised of a magnetic material and a resin comprising a polymeric esterification product of 1,4-benzenedicarboxylic acid polymerized with 1,2,4-benzenetricarboxylic aicd-cyclic 1,2-anhydride and 2,2-dimethyl-1,3-propane diol. The magnetic material can act as both the colorant and magnetic substance, or an additional colorant such as carbon black can be utilized. The toners of the present invention in one preferred embodiment are useful for developing magnetic images.

Abstract: Described is a process for the treatment of certain toner materials, useful in electrophotographic development, which process in one embodiment involves subjecting an electrically conductive toner material to an attrition process, thus causing the removal to a small portion of the surface of the toner while at the same time exposing the underlying inner portion. By preparing toners in accordance with this process the fusing temperature of the toner is lowered by at least 10.degree. F., thereby resulting in better fixing of the toner and higher quality images when such a toner is used as a developer.

Abstract: This specification discloses a method of toner transfer development in which one-component magnetic developer is conveyed to a developing position by the action of a magnetic field and a low frequency alternating electrical bias is applied to the space between a latent image bearing member and a developer carrying member at that position to thereby develop a latent image. This development provides visible images excellent in sharpness and tone reproduction.

Abstract: Disclosed is a novel hole trapping layer and the use of this layer in an overcoated photoresponsive device, this hole trapping layer being comprised of materials of the following formulas: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 which may be the same or different radicals, are selected from aliphatic, substituted aliphatic, aromatic, and substituted aromatic, the substituents including for example alkyl, halogen and the like, x and y are numbers from 2 to about 10 and preferably from 2 to about 4, m and n are numbers of from 1 to 3, the sum of m and n being equal to 4, and Z is a sulfonyl (--SO.sub.2) or a carboxyl (--CO.sub.2) radical. Examples of aliphatic radicals include alkyl of from 1 to about 20 carbon atoms such as methane, ethane, propane, butane, isobutane, pentane, neopentane, heptane, decane, tetradecane, eicosane, and the like.

Abstract: Magnetic toners, methods of their formation and utilization of the toners in various electrophotographic imaging systems is disclosed. The toners disclosed contain a nitrogen containing compound including, for example, amines and quaternary ammonium compounds. Toners containing such compounds are suitable for use in inductive development from a biased magnetic toner brush to an electrostatic image, and further subsequently such images may be transferred preferably by electrostatically type methods to a substrate such as plain bond paper.

Abstract: Electrically conductive developer powder for developing electrostatic images by inductive attraction is provided, with avoidance of practical disadvantages of known "one-component" developer powders, by incorporating finely divided water-insoluble quaternary ammonium salt into thermoplastic resin particles forming the powder, with or without other finely divided additives such as coloring material and/or magnetically attractable material. The specific resistance of the resin particles is lowered to between 10.sup.7 and 10.sup.11 ohm. cm by from 8 to 35% by weight of the quaternary ammonium salt, and can be lowered further by additions of fine conductive material such as carbon black. The resin particles remain sufficiently fusible even when they also contain enough magnetically attractable material, e.g. about 50% by weight, to render them transportable by a magnetic powder-applicator.

Abstract: A ferrite powder type magnetic toner used in an electrophotography. It comprises a resinous component and a ferrite having a spinel structure comprising components of iron oxide at a ratio of 99.9 to 51 mole % as Fe.sub.2 O.sub.3 and at least one metal oxide selected from the group consisting of manganese oxide, nickel oxide, cobalt oxide, magnesium oxide, copper oxide, zinc oxide and cadmium oxide at a ratio of 0.1 to 49 mole % as MO wherein M represents Ni, Co, Mg, Cu, Zn or Cd.

Abstract: Disclosed is an electrostatic image developing process using a magnet roll and a magnetic toner of specified flux density.

Abstract: A particulate magnetic toner for use in a process for developing latent electrostatic images to toner images with a magnetic brush consists predominantly of a magnetic material and a resin of insulating properties. Each toner particle has a portion containing the magnetic material, said material extending through the particle and at least exposed on opposing surfaces of each toner particle to oppose the magnetic materials of other toner particles.

Abstract: Magnetic toner employable as a developer for electrophotographic duplication system consisting of the steps of developing electrostatic latent image on a carrier, overlaying a copying sheet on said carrier of developed image, and transferring the developed image to said sheet, characterized by containing magnetic fine particles of a electric resistivity from 10.sup.9 .about.10.sup.16 .OMEGA..multidot.cm (at 4000 V/cm DC) and dielectric constant from 2.6.about.5.

Abstract: A pressure fixable capsule toner encapsulated with an insulating material is featured by a main particle size located within a range from 5 to 25.mu., by a particle size distribution that at least 70% in number of the toner particles are within a size range of .+-.3.mu. of the main particle size, and by a relationship 0.02.ltoreq.(a-b)/b.ltoreq.0.4 wherein a and b respectively stand for the main particle size of the capsule toner and core material in microns.

Abstract: Dry developer for the development of electrophotographic latent images, consisting of a single type of very fine particle containing an electrically conductive substance, a magnetic substance and a binder, characterized in that it has a high conductivity, greater than 10.sup.-2 Siemens cm, and in that this conductivity is independent of the value of the electrical field applied and its use in a process for development of electrophotographic latent images wherein it is applied from an insulating surface.

Abstract: In controlling the operation of an electrostatic apparatus to produce a large number of copies from an electrostatic image in a multiple copy process there is utilized a toner substance comprising a magnetic carrier composition in which each particle of the composition comprises a ferromagnetic material and a resin, the effective conductivity of the composition being determined by testing means separate from the electrostatic apparatus such that the effective conductivity is measured while the composition is free of absorbed water vapor and other gases encountered under operating conditions with the electrostatic apparatus.