Abstract: A reusable electrophotographic element comprising a photoconductive layer containing sensitized zinc oxide particles and first and second binding agents that are incompatible is produced by employing as the first binding agent a macromolecular compound that has a higher affinity to zinc oxide than the second binding agent, is largely deposited on the zinc oxide, has an average molecular weight of at least 12,000 and is present in the photoconductive layer in an amount of 1.5 to 9% by weight calculated on the zinc oxide, with the second binding agent present in substantially larger amount. The photoconductive layer is formed of agglomerates of zinc oxide particles substantially enveloped in the first binding agent, which agglomerates have a diameter of between 2.5 and 6 .mu.m and are stuck together by portions of the second binding agent, thus providing a substantially porous photoconductive layer having a negative charge density of at most 1 m Coulomb per m.sup.2.

Abstract: Disclosed is an electrophotographic photosensitive material comprising a photosensitive layer containing a tris-azo pigment represented by the following formula: ##STR1## wherein the ring A.sub.1 and A.sub.2 may have a halogen atom, an alkyl group or alkoxy group as a substituent at the ortho-position to the azo group, Z stands for a benzene ring, naphthalene ring, indole ring, carbazole ring or benzofuran ring fused to the benzene ring B, and R stands for an unsubstituted or substituted phenyl, naphthyl or heterocyclic group.This photosensitive material has a high sensitivity to rays in a broad wavelength region and is excellent in the resistance in the printing operation.

Abstract: An improved process for preparing a single component toner or developer composition is disclosed whereby toner fines are removed from the composition prior to the addition of conductive carbon followed by a reclassification step to remove excess carbon particles, i.e., those carbon particles not attached to the toner.

Abstract: A xeroradiographic material comprising a substrate at least one surface of which is electrically conductive, and an X-ray sensitive layer provided on the conductive surface of the substrate and essentially consisting of an organic binder, .gamma.-form crystal grains of a bismuth oxide-based compound oxide and n-type semiconductor grains dispersed in the organic binder. The material is made by dispersing these grains in an organic binder solution, applying the dispersion onto the conductive surface of the substrate, drying the coat of the dispersion at a temperature in a range not lower than the boiling point of the solvent but below the softening point of the organic binder to form an X-ray sensitive layer, and heat-treating the X-ray sensitive layer at a temperature in a range not lower than the softening point of the organic binder but below the temperature at which the organic binder begins decomposing.

Abstract: As a developer for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc., there is employed a developer containing a finely divided silicic acid which is a finely divided silicic acid synthesized by a wet process and has a pH value of 6 to 11 when suspended at a concentration of 4% by weight in distilled water and the developer can be positively charged strongly and uniformly to visualize the negative electrostatic images, giving a high quality image.

Abstract: An electrophotographic photosensitive member comprises a layer containing at least one azo pigment represented by the following formula (I): ##STR1## in the formula, Cp represents a coupler residue; A.sub.1 and A.sub.2 each represent a divalent organic residue; n represents 0 or 1; and when n is 0, A.sub.3 represents substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or --(CH.dbd.CH).sub.l --R', wherein R' is a substituted or unsubstituted heterocyclic ring residue an l is 0, 1 or 2, and when n is 1, A.sub.3 represents a divalent organic residue.

Abstract: A developer for use in developing an electrostatic latent image according to electrography comprises a mixture of a carrier and a toner having a property of being triboelectrically charged to a positive polarity when held in frictional contact with the carrier. The toner includes a binders which is a thermoplastic resin having a Lewis acid-functional group.

Abstract: This invention relates to a process for rapidly charging uncharged toner particles to a positive polarity, which comprises adding uncharged toner particles to a positively charged developer composition comprising carrier particles and toner particles, the charged and uncharged toner particles containing conductive particles or conductive patches on their surface, which conductive patches are of a higher positive triboelectric charge than the toner polymer, contacting the charged toner particles with the uncharged toner particles causing positive charges to be transferred from the conductive particles on the charged toner particles, to conductive particles on the uncharged toner particles, within a period of from about 5 seconds to about 2 minutes, thereby resulting in substantially the same level of positive charge intensity for both the original charged toner particles and the added toner particles, such charge intensity ranging from about 5 microcoulombs per gram to about 50 microcoulombs per gram.

Abstract: There is disclosed an electrophotosensitive receptor which comprises a conductive support and an electrophotosensitive layer which comprises a carrier transporting material and a specified trisazo compound wherein the azo compound is applied as a coating solution containing a solvent or as a liquid dispersion mixture containing a dispersion medium. Alternatively, the electrophotosensitive receptor comprises a conductive support and an electrophotosensitive layer which comprises said azo compound wherein the azo compound is applied as a coating solution containing a solvent and a binder or as a liquid dispersion medium containing a dispersion medium and a binder.

Abstract: New liquid developers for electrophotography comprise (a) a coloring agent, (b) a charge control agent and (c) one or more of a polyethylene, a polypropylene, an ethylene copolymer and a propylene copolymer, with or without (d) a hydrocarbon resin soluble in a hydrocarbon solvent and containing a 1,3-pentadiene moiety, in an electro-insulating liquid. These developers have an excellent etching resistance and a high dispersion stability.

Abstract: Disclosed is a photosensitive plate for electrophotography, which comprises a conductive substrate and a layer of a composition formed by dispersing a photoconductor in a binder resin, which is formed on the substrate, wherein the resin binder comprises an epoxy resin component and an amine type curing agent component and the resin binder further comprises an acid anhydride as the ozone deterioration preventing agent.This photosensitive plate is excellent in the ozone resistance and the moisture resistance.

Abstract: Protonic acid-free photoconductive compositions and elements comprising a photoconductor and, as a sensitizer, a 4-tertiaryaminobenzo?b!pyrylium salt or a 4-tertiaryaminobenzo?b!thiopyrylium salt. The resulting compositions and elements exhibit low persistent conductivity.

Abstract: In an electrophotographic light-sensitive material having on a conductive support a light-sensitive layer composed of a charge generating material and a charge transporting material. A hydrazone compound is used as the charge transporting material for providing the light sensitive layer having high sensitivity and less residual surface potential. The light-sensitive layer is stable to oxidation by ozone generated by corona discharging as well as to heat and light, results in less dark decay of the surface potential. Furthermore, the layer shows less deviation in residual potential and sensitivity due to repeated use.

Abstract: An electrophotographic image forming member having on a substrate a photoconductive layer constructed by laminating a crystalline silicon layer and an amorphous silicon layer.

Abstract: An electrophotographic photosensitive member is characterized by having a layer containing at least one of hydrazone group compounds represented by the following formula (1) or of ketazine group compounds represented by the following formula (2): ##STR1## In the formula, R.sub.11 and R.sub.12 independently of one another represent hydrogen, substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclic radical; R.sub.13 and R.sub.14 independently of one another represent subsituted or unsubstituted alkyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclic radical; and R.sub.15 represents a divalent organic residue. ##STR2## In the formula, R.sub.21, R.sub.22, R.sub.23, and R.sub.24 independently one another represent substituted or unsubstituted alkyl, substituted or substituted aralkyl, or substituted or unsubstituted aryl, or R.sub.21 and R.sub.

Abstract: Disclosed is an electrophotographic photosensitive composition which comprises a phthalocyanine type photoconductor dispersed in an electrically insulating resin medium, wherein a nitrophthalic anhydride represented by the following formula: ##STR1## wherein n is a number of 1 or 2, is incorporated as a sensitizer.

Abstract: An electrophotographic recording medium which consists essentially of an electrically conductive base and a photosemiconductive double layer which comprises a first layer containing charge carrier-producing dyes, and a second layer containing one or more compounds which are charge carrier-transporting when exposed to light, wherein perylene-3,4,9,10-tetracarboxylic acid N,N'-bis-(2',6'-dichlorophenyl)-diimide is employed as the charge carrier-producing dye, and the production of this recording medium.

Abstract: A printing member for electrostatic photocopying, comprises a substrate having a conductive surface and a photoelectric-sensitive, electrically chargeable layer deposited on the conductive surface of the substrate. The electrically chargeable layer has a non-single crystal semiconductor layer having a built-in-potential, or the non-single crystal semiconductor layer and an insulating or semi-insulating layer.

Abstract: An aqueous composition-sensitive photoconductive composition useful in the preparation of aqueous composition decoatable electrophotographic elements, such elements and low cost lithographic printing plates prepared from said elements the aqueous composition-sensitive photoconductive composition comprising the admixture of an inorganic photoconductor, an organic photoconductor and an aqueous composition-sensitive resin, and, if desired, to increase exposure speed, a dyestuff photosensitizer.

Abstract: Polyesters having recurring units derived from diols and diacids and recurring units derived from p-hydroxybenzoic acid is disclosed. Electrographic developer compositions comprising toner particles containing the polyesters are also disclosed.