Abstract: A method for printing information on a substrate having security features includes the steps of: applying a DC potential difference (DC.sub.TB) between a back electrode and a toner delivery means to create a flow of toner particles from the toner delivery means to the back electrode; interposing a printhead structure, the printhead structure having printing apertures and control electrodes around the printing apertures, between the toner delivery means and the back electrode so as to create a spacing having a width L between the printhead structure and the back electrode and to imagewise control the flow of toner particles; passing the substrate having a thickness T in .mu.m through the spacing; adjusting the spacing between the printhead structure and the back electrode such that the width of the spacing L is greater than or equal to 1.5 T; adjusting the DC potential difference (DC.sub.TB) such that the relationship .vertline.DC.sub.TB .vertline./L, expressed in volts per micrometer (V/.mu.

Abstract: A device for direct electrostatic printing (DEP) including a back electrode, a printhead structure made from an insulating material and having a control electrode in combination with printing apertures, and a toner delivery apparatus that presents a cloud of toner particles in the vicinity of the printing apertures, in which the printhead structure is tightly stretched over a frame by means of lateral forces and the printhead structure has an overall flatness equal to or better than 50 .mu.m.

Abstract: A device for direct electrostatic printing is provided wherein a flow of toner particles in a electrical field from a toner source to the surface of an intermediate image receiving member is image-wise modulated by a printhead structure with printing apertures and control electrodes, and wherein the toner image of the intermediate image receiving member is transferred to a final substrate and fixed to that final substrate. The intermediate member has a surface energy lower than 40 mN/m and surface roughness Ra smaller than 3.0 .mu.m. The transfer of the toner image from the intermediate image receiving member to the final substrate can be aided by electrostatic attraction and/or by tackifying the toner image on the intermediate member.

Abstract: A device for use in the technique of direct electrostatic printing (DEP) on an intermediate or final substrate is described, comprising:a receiving member support 5a printhead structure 6 having control electrodes 6a on its back side, in combination with apertures 7 and at least one common shield electrode 6b on the front side ;a toner delivery means 1 presenting a cloud 4 of toner particles in the vicinity of the apertures 7.The printhead structure 6 is made of a plastic isolating substrate, and has at least two rows of apertures. Preferentially each row has one common shield electrode (6b, 6c) at the front side of the printhead structure. The individual control electrodes on the back side are galvanically isolated per aperture from each other and from each shield electrode. The control electrodes are arranged around the apertures. The size or diameter of the apertures of one row is substantially different from the size of the apertures of a second row.

Abstract: An ink jet printing process comprising the steps of image-wise projecting droplets of liquid onto a receiving material thus bringing into working relationship on said receiving material a reducible metal compound (A), a reducing agent (B) for said metal compound and physical development nuclei (C) that catalyze the reduction of said metal compound to metal.

Abstract: Disclosed herein is a method for direct electrostatic printing with reduced banding, which comprising the steps of creating a potential difference between a back electrode and a magnetic brush assembly having a stationary mounted core and a sleeve rotatably mounted around the core, and rotating the sleeve at a rotational speed V.sub.rot which is higher than 100 rotations per minute; applying a developer with toner particles and magnetically attractable carrier particles on the magnetic brush assembly; creating a flow of toner particles directly from the magnetic brush assembly to the back electrode; interposing a printhead structure, having printing apertures and control electrodes around the printing apertures, between the magnetic brush assembly and the back electrode, for image wise controlling the flow of toner particles; passing a substrate at a speed V.sub.

Abstract: A printhead structure (106) for use in a DEP (Direct Electrostatic Printing) device is provided, made from an insulating material comprising control electrodes in combination with printing apertures, characterized in that:(i) the printhead structure comprises individual control electrodes (106a), each of the individual control electrodes being combined with at least one aperture (107), on one side of the printhead structure,(ii) each of the individual control electrodes (106a) is located on the same side of the insulating material and(iii) the apertures are rectangles with an aspect ratio (AR), defined as the ratio of the width of the apertures in their long axis (WL) over the width of the apertures in a direction perpendicular to this long axis (WD), larger than 1. In a preferred embodiment each single control electrode controls two printing apertures with AR>1 and these two apertures are separated by a portion of the control electrode controlling them.

Abstract: A DEP device adapted for grey-scale printing comprising a back electrode (105), a printhead structure (106), an array of printing apertures (107) in the printhead structure (106) through which a particle flow can be electrically modulated by a control electrode (106a), a toner delivery means (101), at least one control means (111) for applying an electric field to the control electrodes, wherein:(i) the control means controls each single control electrode to enable the printing through each single printing aperture (107) of pixel dots (PD), each of the pixel dots intended to have a density D, and(ii) the control means controls the printing of the pixel dots through the each single printing aperture as a function of both the intended density (D.sub.intend) and the density (D.sub.prev) previously produced through the single printing aperture, i.e. the control means use "previous correction".

Abstract: A method for applying an ink-receiving layer to any given substrate comprising the steps of laminating a sheet or web material comprising at least three layers which include a temporary support having a thickness between 40 and 100 .mu.m, an ink-receiving layer and an adhesive layer onto said given substrate, and stripping the temporary support away to free the ink-receiving layer. The ink-receiving layer, according to the present invention, is adapted to be used with water-based inks and enables the end-user of said image-recording member to transfer that ink-receiving layer to any one of the substrates of his choice.

Abstract: A method for direct electrostatic printing (DEP) on an intermediate substrate or on a final substrate is provided, using a device that comprises a back electrode (105), a printhead structure (106) comprising a control electrode in combination with apertures (107), and a toner delivery means (101) presenting a cloud (104) of dry toner particles in the vicinity of said apertures (107), characterised in that(i) the toner particles have as topological criterium that the ratio of the length of the long axis of the projected microscopic image of said particles to the length of the short axis, is between 1.00 and 1.40 and(ii) the toner particles after addition of 0.5% by weight of fumed hydrophobic silica having a specific surface area of 260 m.sup.2 /g show a ratio of apparent density (.rho..sub.app) over real density (.rho..sub.

Abstract: A photographic material is provided comprising a support, a subbing layer, at least one hydrophilic gelatinous silver halide emulsion layer, optionally one or more other hydrophilic gelatinous layer(s) and a core-shell latex polymer, comprising a core (co)polymer and a shell (co)polymer characterized in that(i) said core-shell latex is present in at least one of said hydrophilic gelatinous layers,(ii) said shell (co)polymer comprises moieties A derived from at least one ethylenically unsaturated monomer having a reactive methylene group and(iii) said moieties A present in said shell (co)polymer make up between 1 and 30% by weight of all moieties present in both said core and said shell (co)polymer and(iv) said moieties A present in said shell (co)polymer make up between 2 and 50% of all moieties present in said shell (co)polymer.The material shows both high dimensional stability and high scratch resistance.

Abstract: Process for the manufacture of a lithographic printing plate comprising the steps of:(1) information-wise projecting droplets of liquid, onto a receiving material having a hydrophilic surface to form a silver image by bringing into working relationship on said hydrophilic surface a reducible silver compound (A), a reducing agent (B) for said silver compound and physical development nuclei (C) that catalyze the reduction of said silver compound to silver metal, and(2) hydrophobizing the silver image that has been obtained through said step (1) e.g. by overall contacting the printing surface with a hydrophobizing substance for said silver image or hydrophobizing said silver image by imagewise depositing said hydrophobizing substance thereon.

Abstract: An ink-jet recording element is provided comprising a polymeric film substrate or a resin coated paper substrate and at least one ink-receiving layer coated thereon comprising at least one binder and at least one mordanting agent characterized in that said mordanting agent comprises a polymer containing a phosphonium moiety. Preferably said mordanting agent consists of a copolymer of ethylenically unsaturated monomers containing a phosphonium moiety co-polymerized with N-vinyl imidazole or 2-methyl-2-vinyl imidazole and optionally other co-polymerizable monomers or of a mixture of from 5 to 70% by weight, of a polymer containing a phosphonium moiety, and obtained by homo- or co-polymerization of ethylenically unsaturated monomers and from 30 to 95% by weight, of a second polymer, which is free from cationic groups and has been obtained by homo- or co-polymerization of N-vinyl imidazole or 2-methyl-2-vinyl imidazole and optionally other co-polymerizable monomers.

Abstract: Photographic element having high dimensional stability comprising a hydrophobic polyester film support, a barrier layer retarding diffusion of water in liquid or vapor phase into the hydrophobic polyester film support, and at least one hydrophilic image-precursor layer, said barrier layer being a vapor-deposited glass layer.