Abstract: Xeroprinting masters are formed by first forming a toner mask. The mask is used to expose a xeroprinting master material exhibiting persistent conductivity in response to a given wavelength and intensity of radiation. The toner mask can be formed and transferred to the xeroprinting material without fusing. After exposure the masking toner can be cleaned off providing a planographic master. Multicolor images are formed by forming two or more masking images, and transferring them to two or more master surfaces. After irradiation and cleaning each master surface is used as a xeroprinting master for a particular color in a multicolor duplicating system.

Abstract: A process for the preparation of encapsulated toner compositions which comprises a core dispersion obtained by adding pigment to a monomer, and wherein the pigment is sterically stabilized with a block copolymer; dispersing the resulting core dispersion into an aqueous solution containing an emulsifier; adding thereto an aqueous solution containing a shell monomer; encapsulating the core dispersion by interfacial polymerization of said shell monomer; and heating to initiate a free radical polymerization of the core monomer.

Abstract: The present invention relates to an electrophotographic sensitive member comprising a photoconductive amorphous silicon carbide layer.An amorphous silicon layer has superior abrasion resistance, heat resistance, antipollution property, photosensitive characteristic and the like.However, an amorphous silicon layer itself has a low dark resistance, so that dopants, such as boron, are added thereto but a dark resistance of 10.sup.12 .OMEGA..multidot.cm or more required for the case where it is used as an electrophotographic sensitive member has never been obtained.The present inventors have found before that an amorphous silicon carbide layer has a large carrier-mobility and photoconductivity and its dark resistance of 10.sup.13 .OMEGA..multidot.cm or more can be easily obtained regardless of the existence of dopants and furthermore an electrophotographic sensitive member, which can be positively and negatively charged by the selection of the dopants, can be obtained.

Abstract: Disclosed a process for the preparation of polymer particles, which comprises suspending a polymerizable monomer, a radical initiator and a hardly soluble inorganic dispersant in a dispersion medium and carrying out polymerization in this state, wherein a hardly soluble inorganic dispersant, the solubility of which is changed according to the pH value in the dispersion medium and which is precipitated at a pH value within a certain pH value region of the dispersion medium, is used as the dispersant, suspension of the polymerizable monomer in the dispersion medium is carried out in the state where the dispersant is dissolved in the dispersion medium, an acid or base is then added to adjust the pH value of the dispersion medium to a predetermined level to precipitate the dispersant, and the polymerization is initiated in the state where oil drops having a fine particulate size are formed.

Abstract: Disclosed is a dry toner composition which comprises a resin, hydrophilic silica particles having dyes covalently bonded to the particle surfaces through silane coupling agents, and a polymer having at least one segment capable of enhancing the dispersability of the silica particles in the resin and at least one segment capable of adsorbing onto the surface of the silica particles. In one embodiment, the polymer segment capable of adsorbing onto the surface of the silica particles is ionophoric and capable of complexing with a salt, thereby incorporating a toner charge control additive into the polymer.

Abstract: The invention provides coated carrier particles and dry electrographic developers comprising a mixture of the carrier particles and toner particles. Each of the carrier particles comprises a core particle having a polymeric overcoat comprising a blend of a fluorine-containing polymer and a modifying polymer comprising poly(p-t-butylstyrene) or a copolymer of p-t-butylstyrene and a C.sub.1 -C.sub.4 alkyl methacrylate.

Abstract: A method for preparing an electrophotographic photoreceptor is disclosed, which comprises a substrate having thereon a charge generating layer containing an amorphous silicon as a main component and a charge transporting layer containing aluminum oxide as a main component, wherein the charge transporting layer is formed by an ion plating method while introducing oxygen gas.

Abstract: A resin-coated magnetic carrier for two-component developers which comprises magnetic particles and a resin coating formed on the individual magentic particles is described. The resin coating is made of a cured resin composition comprised of an alkylated melamine resin whose moelcular weight satisfies the followin inequalityM.gtoreq.1100C-400wherein M represents a weight average molecular weight of the resin and C represents the number of carbon atoms in the alkyl moiety, and an acryl-modified silicone resin. The use of the composition is effective in preventing the coated particles from melt adhesion and in forming a smooth and uniform coating layer on individual particles. The resin-coated carrier is significantly reduced in amount of spend carrier and has good durability, moisture resistance, chargeability.

Abstract: A toner composition is disclosed which comprises a mixture of toner particles with finely powdered acylic polymer, and finely powdered silica dispersed in the mixture, wherein the finely powdered acrylic polymer is present in an amount of 0.05 to 0.15 parts by weight per 100 parts by weight of the toner particles and the weight ratio of silica to acrylic polymer is within the range of 1 to 5:1. Also disclosed is a method for preparing the toner composition.

Abstract: Disclosed is a toner for the electrophotography, which comprises as a main component a styrene/acrylic copolymer having at least two molecular weight distribution peaks, the molecular weight (Mw) of the peak on the lowest molecular weight side being lower than 13000, wherein the toner contains a charge controlling agent dispersed therein at a concentration of at least 0.3% by weight and the charge controlling agent has such a particle size distribution that the area ratio of particles having a particle size larger than 2.5 .mu.m is at least 80% based on the section of the toner. If this toner is used, the fixing-possible temperature can be broadened while increasing the fixing ratio without reduction of the performances of the toner.

Abstract: A electrophotographic printing plate precursor comprising an electrically-conductive support having thereon a photoconductive layer containing at least photoconductive pigments and a binder resin, wherein said photoconductive pigments are phthalocyanine pigments and said photoconductive layer further comprises a compound represented by the general formula (I), (II) or (III): ##STR1## wherein Z represents a sulfur or oxygen atom; Ar represents a monovalent aromatic hydrocarbon group or monovalent heterocyclic group; R.sub.3 represents a hydrogen atom, alkyl group, aryl group or aralkyl group; Ar and R.sub.3 may together form a ring; and R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group, aryl group or aralkyl group, with the proviso that the aromatic hydrocarbon group and heterocyclic group represented by Ar and the alkyl, aryl and aralkyl group represented by R.sub.1, R.sub.2 and R.sub.

Abstract: An electrophotographic liquid developer composition is provided containing a charge director which is a salt of a trivalent metal and an aromatic acid such as diisopropyl salicylic acid. For consecutive color toning processes, it is preferred that the concentration of charge director be maintained below some defined maximum value so that substantially all of the charge director is associated with toner. Methods for making and using the novel compositions are provided as well.

Abstract: A method transferring dry toner particles from the surface of an element which has a surface layer comprising polyester or polycarbonate thermoplastic polymeric binder resin matrix to a receiver which comprises a substrate having a polymeric coating on a surface in which the polymeric coating comprises a blend of:(i) from about 40 to about 90 percent by weight based on the total weight of the blend of a thermoplstic addition polymer and(i) from about 10 to about 60 percent by weight based on the total weight of the blend of a thermoplastic addition polymer having a ratio of weight average molecular weight to number average molecular weight in the range of from about 1:1 to 10:1.wherein the Tg of the thermoplastic addition polymers in the blend is less than approximately 10.degree. C.

Abstract: A method is provided for non-electrostatically transferring dry toner particles which comprise a toner binder and have a particle size of less than 8 micrometers from the surface of an element which has a surface layer comprising a film-forming, electrically insulating polyester or polycarbonate thermoplastic polymeric binder resin matrix and a surface energy of not greater than approximately 47 dynes/cm, preferably from about 40 to 45 dynes/cm, to a receiver which comprises a substrate having a coating of a thermoplastic addition polymer on a surface of the substrate in which the Tg of the polymer is less than approximately 10.degree. C. above the Tg of the toner binder and the surface energy of the thermoplastic polymer coating is approximately 38 to 43 dynes/cm by contacting the toner particles with the receiver which is heated to a temperature such that the temperature of the thermoplastic polymer coating on the receiver substrate during transfer is at least approximately 15.degree. C.

Abstract: An electrophotographic photoreceptor is disclosed, comprising an electrically conductive substrate having thereon and a light-sensitive layer, said light-sensitive layer comprising an electric charge generating layer and an electric charge transporting layer, wherein the electric charge generating layer contains an electric charge generating organic pigment having positive hole transporting properties and a pyrylium compound represented by the formula (I) or (II): ##STR1## wherein X is an oxygen atom or a sulfur atom; R.sub.1 to R.sub.5 are each a hydrogen atom, and alkyl group, a cycloalkyl group, an alkoxycarbonyl group, a benzyl group, a substituted or unsubstituted styryl group, or a substituted or unsubstituted phenyl group, and Z.sup..crclbar. is an anion.

Abstract: A process for the preparation of a toner polymer which comprises the steps of carrying out suspension polymerization of a monomer having a polymerizable vinyl group in the presence of polyvinyl alcohol as a dispersant, and then conducting oxidative decomposition of polyvinyl alcohol anchored to polymer particles obtained by suspension polymerization.

Abstract: This invention provides a toner composed of associated particles of secondary particles comprising primary particles of a polymer having an acidic or basic polar group and particles of a coloring agent and optionally a charge controlling agent and a process for producing the toner. Preferably, the contacting portions among the secondary particles are at least partly melt-adhered by film formation. The toner of the invention has excellent advantages. It has a much higher resolution than conventional products. It has excellent chargeability and causes hardly any occurrence of fogging.

Abstract: Photoconductive compositions of methine dye and aggregated pyrylium dye which, when incorporated into charge generation compositions for use in photoconductive film elements, display extended spectral sensitivity, enhanced visibility, and high resolution characteristics compared to either dye used separately. Preferred methine dyes are cyanine dyes with near infra red region sensitivity. The film elements also display reduced energy requirements for discharge.

Abstract: A photoconductor for electrophotography comprises a substrate and a photosensitive layer formed on the substrate and including a novel tetrakisazo compound. The one type of the tetrakisazo compound is represented by the following general formula. ##STR1## Wherein A stands for a coupler residual group and R stands for one of a hydrogen atom, an alkyl group and an aryl group which may have a substituent group.

Abstract: A process for the preparation of encapsulated toner compositions which comprises (1) providing a core comprised of a monomer capable of being polymerized by free radical polymerization, a colorant or pigment, a free radical initiator, a polymer and a first shell monomer dissolved in the core monomer; (2) dispersing said core components in an aqueous phase containing a surfactant, an antifoaming agent, and a phase transfer agent; (3) adding a second shell monomer to the aqueous phase; (4) encapsulating the core components by accomplishing polymerization of the first and second shell monomers; (5) heating the aqueous phase dispersion of (2) and (3) thereby effecting in situ polymerization of the core monomers; and (6) heat spheroidizing the polymerized shell of (4) by heating.