Abstract:
An electrophotographic printing plate precursor having satisfactory mechanical strength and water-resistance and suitable to the direct electrical supply system, and a method for development thereof are disclosed.The electrophotographic printing plate precursor comprises an electrically conductive support having thereon a photoconductive layer and a back layer, the back layer being provided on the surface of the support opposite to the photoconductive layer, wherein the back layer comprises at least an outermost layer having a surface resistivity of from 1.times.10.sup.10 to 1.times.10.sup.14 .OMEGA. and an inner layer having a surface resistivity of less than 1.times.10.sup.10 .OMEGA..
Abstract:
An original form for electrophotographic planography includes a paper support having thereon a photoconductive layer including a photoconductive material including at least zinc oxide and a resin binder, the exposure percentage of the zinc oxide on a surface of the photoconductive layer being in the range of from 2.1 to 5%.
Abstract:
An excellent electrophotographic lithographic printing plate precursor capable of exhibiting a stable electrophotographic sensitivity and toner fogging density as well as less occurrence of background stains during printing can be produced in effective manner. The feature consists in a process for the production of an electrophotographic lithographic printing plate precursor having at least a photoconductive layer on a support, comprising coating a composition for a photoconductive layer comprising, as predominant components, a photoconductive material and a resin binder onto the support and then drying it by a drying air whose humidity is controlled to provide an absolute humidity of 5 to 70 g/kg . dried air.
Abstract:
A liquid developer for electrostatic photography is described, comprising at least a resin dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 ohms.cm and a dielectric constant of not more than 3.5. The resin is a copolymer resin obtained by polymerizing a solution containing at least one monofunctional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble upon polymerization and at least one specified monomer (B) containing an aliphatic group having at least 8 carbon atoms and being copolymerizable with the monomer (A), in the presense of a resin not containing a grafting group polymerizable with the monomers and being soluble in the non-aqueous solvent. The resin may be colored by dissolving at least one organic dye in the dispersion of the resin and heating the mixture. The developer has excellent dispersion stability, redispersibility, fixability and preservability.
Abstract:
Disclosed is a liquid electrophotographic developer comprising a resin prepared by polymerizing selected monomers to provide a developer composition having good storage stability and redispersibility.
Abstract:
An electrophotographic printing plate precursor having satisfactory mechanical strength and water-resistance and suitable to the direct electrical supply system, and a method for development thereof are disclosed.The electrophotographic printing plate precursor comprises an electrically conductive support having thereon a photoconductive layer and a back layer, the back layer being provided on the surface of the support opposite to the photoconductive layer, wherein the back layer comprises at least an outermost layer having a surface resistivity of from 1.times.10.sup.10 to 1.times.10.sup.14 .OMEGA. and an inner layer having a surface resistivity of less than 1.times.10.sup.10 .OMEGA..
Abstract:
The present invention aims at, in an electrophotographic lithographic printing plate precursor, improving the construction and composition of back layers and in particular, preventing occurrence of printing scum by rubbing and increasing the number of prints until printing wrinkles occur. The feature of the present invention consists in an electrophotographic lithographic printing plate precursor comprising, at least, a photoconductive layer on one surface of a base and a back layer on the other surface thereof, in which the back layer comprises an outermost layer containing a hydrophilic high molecular material and an innerlayer having a Cobb's water absorbing capacity of at most 25 g/m.sup.2 (45 minute value).
Abstract:
Disclosed is a process for producing a lithographic printing plate using a lithographic printing plate precursor comprising a support having a volume resistivity of more than 1.times.10.sup.10 .OMEGA..cm, an electrically conductive layer provided on one surface of the support and having a volume resistivity of 1.times.10.sup.5 .OMEGA..cm or less and a photoconductive layer provided on the electrically conductive layer and containing zinc oxide and a binder, the process comprising applying negative corona discharge to the lithographic printing plate precursor from the photoconductive layer side and at this discharging, contacting an electric conductor having an earth potential at least with the support of the lithographic printing plate precursor to electrically charging the photoconductive layer of the lithographic printing plate precursor.
Abstract:
A liquid developer for electrostatic photography comprising a carrier medium having an electrical resistivity of not less than 10.sup.9 106.cm and a dielectric constant of not more than 3.5 having dispersed therein at least a resin, wherein said resin is a copolymer resin obtained by copolymerizing (1) a solution containing at least one copolymer having an unsaturated bond obtained by copolymerizing at least one monomer (A) represented by formula (I) shown below and at least one monomer (B) represented by formula (II) shown below, and reacting the resulting copolymer with at least one monomer (C) represented by formula (III) shown below, (2) at least one monomer (D) which is soluble in the carrier medium but becomes insoluble upon polymerization, and (3) at least one monomer (E) represented by formula (IV) shown below to obtained a resin dispersion: ##STR1## wherein a.sub.1, a.sub.2 a.sub.3, b.sub.1, b.sub.2, b.sub.3, d.sub.1, d.sub.2, d.sub.3, e.sub.1, e.sub.2, e.sub.3, X, Y, V, Z, L, F, Q, G, R.sub.1, R.sub.2, R.sub.3, T.sub.1, T.sub.2, U, m and n are defined in the specification. The developer is excellent in redispersibility, preservability, stability, image reproducibility, and fixing properties and is capable of producing a master plate for offset printing having excellent printing durability.
Abstract:
An electrophotographic lithographic printing plate precursor capable of well maintaining both the electrophotographic properties and the printing properties is provided, which comprises, at least, a photoconductive layer on one side of a support and an under layer directly under the photoconductive layer, in which the under layer consists of a plurality of layers comprising an outermost layer having a surface resistivity of at most 1.times.10.sup.11 .OMEGA. and an inner layer having a Cobb's water absorbing capacity of at most 15 g/m.sup.2 (45 minute value) or having a Young's Modulus of at most 1000 kg/cm.sup.2.
Abstract translation:提供了能够良好地保持电子照相特性和印刷性能的电子照相平版印刷版原版,其至少包括在载体的一侧上的光电导层和直接在光电导层下的下层,其中下 层包括多个层,其包含具有至多1×10 11欧米茄的表面电阻率的最外层和具有至多15g / m 2(45分钟值)的Cobb吸水能力或至多具有至多杨氏模量的内层 1000 kg / cm2。