MXPA99009873A - Separator of images that has a conformable layer for electrostatic printing by conta - Google Patents

Abstract

An electrostatic contact print image separator having a substrate, and on top of it a layer conformable with a conductive or semiconductive polymer, and an optional external release layer placed on the conformable layer, and electrostatic contact printing apparatuses including the image separator

Description

IMAGE SEPARATOR THAT HAS A CONFORMABLE LAYER FOR ELECTROSTATIC PRINTING BY CONTACT FIELD OF THE INVENTION 5 This invention relates to image separators and their manufacture. These image separators are useful in an electrostatic printing machine, especially a printing machine that employs an electrostatic contact printing process. The 10-image separators herein, comprise a substrate, a conformable layer, and an optional removable outer layer. In optional embodiments, the conformable layer may comprise conductive particles dispersed or contained therein.

BACKGROUND OF THE INVENTION In the art have. Several methods have been described to reveal a latent image of electrostatic printing or copying systems. Of particular interest with respect to the present invention, is the concept of Printing ? \ - Electrostatographic by Contact (CEP), which includes a variety of related liquid xerographic methods. In one process, an electrostatic image is produced on an image-bearing member. The image-bearing member is then coated with a uniform layer of a liquid organic pigment. Preferably, this REF: 31255 layer of liquid organic pigment is a thin and substantially uniform layer of highly concentrated liquid developer material. The organic pigment layer is divided into the entire image between the member containing the image and an image separator, followed by the transfer of the image separator to an image substrate, such as a paper. The development of the latent image occurs after the separation of the member containing the image and the image separating surface. The development occurs as a function of the electric force generated by the latent image. In this process, the migration of organic pigment particles or 'Electrophoresis is replaced by direct surface-to-surface transfer of a layer of organic pigment. The migration of particles is induced by imaging forces. For the description of the present, the concept of latent image development via direct surface-to-surface transfer of an organic pigment layer via imaging forces, will be generally identified as Contact Electrostatic Printing (CEP). In general, the methods that include CEP, are disclosed in the application of US Patent Serial No. 08 / 883,292, file number of the agent D / 97135, filed on June 27, 1997, entitled "Formed Latent Electrostatic Image"; U.S. Patent Application Serial No. 08 / 884,236, file number of agent D / 97136, filed on June 27, 1997, entitled "Loading of Organic Pigment Layers to Form Images by Air Breaking for Image Development"; and US application Serial No. 09 / 004,629, filing number of agent D / 97546, filed on January 8, 1998, entitled "Loading Organic Pigment Layer to Reveal Images". The descriptions of those references are hereby incorporated by reference in their entirety. The image separator should have sufficient release properties to adequately detach the developed image to a printing substrate such as a paper. The image separator must also be sufficiently conformable to be transferred to rough printing substrates. Additionally, since the transfer in the CEP is desirable, the image separator is preferably stable at temperatures up to about 125 ° C.

BRIEF DESCRIPTION OF THE INVENTION The present invention is completed in embodiments providing (a) an image-bearing member comprising a developed image, wherein the developed image comprises a primary latent image and a secondary latent image; and (b) an image separator comprising the secondary latent image, wherein the image separator comprises: (i) a substrate; and on it (ii) a conformable layer comprising a conductive or semiconducting polymer; and (iii) an optional external release layer, placed on the conformable layer. Adhesives The embodiments of the invention also include (a) an image-carrying member comprising a developed image, wherein the developed image comprises a primary latent image and a secondary image; and (b) an image separator comprising the secondary latent image, wherein the image separator comprises; i) a substrate; and on it (ii) a conformable layer comprising a polymer selected from the group consisting of silicone rubbers, fluoropolymers, polyurethanes and nitrile rubbers, and comprising a filler selected from the group consisting of metal oxide, carbon black, polymer particles and mixtures thereof; and (iii) an optional external release layer, placed on the conformable layer.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of one embodiment of an electrostatic contact printing apparatus.

Figure 2 is an exploded view illustrating the image-wide loading of an organic pigment layer by a wide-source ion charging device, where the organic pigment layer selectively charged inverse according to an image latent adjacent to it, according to what is contemplated by one embodiment of the present invention. Figure 3 is a cross-sectional view of an embodiment of an image separator demonstrating a two-layer configuration. Figure 4 is a cross-sectional view of one embodiment of an image separator demonstrating a three-layer configuration. Figure 5 is a schematic view of an alternative embodiment of an electrostatic contact printing apparatus, which comprises a deflection roller member. Figure 6 is a schematic view of an alternative embodiment of an electrostatic contact printing apparatus, which comprises a charging device.

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a useful image separator in an electrostatic printing machine, especially a machine that uses electrostatic contact printing processes, where the image separator comprises a substrate, a conformable layer, and a layer optional external removable. Reference is now made to Figure 1, which illustrates an image forming apparatus constructed and operating in accordance with an embodiment of the present invention. In Figure 1 there is shown a first mobile member in the form of an image-bearing member 10, which includes an image-forming surface on any type capable of having a latent electrostatic image formed therein. The image-carrying member 10 is rotated in the direction of arrow 11. In one embodiment, initially, the photoconductive surface of the image-carrying member 10 passes through a charging station 30, which may include a device generating crown of any other loading apparatus for applying a substantially uniform electrostatic charge on the surface of the image-bearing member 10. Various charging devices, such as the loading rollers, charge brushes and the like, as well as induction charging devices and semiconductors can be used to load the member 30. In the embodiment illustrated in Figure 1, the loaded surface is advanced to the image display station 40. The image exposure station projects a light image corresponding to the image. fed on the surface of the loaded image carrying member. The luminous image projected onto the surface of the image-bearing member 10 selectively dissipates the charge thereon to record a latent electrostatic image on the surface of the image-bearing member. After the image-bearing member is exposed, a bark-forming member of the organic pigment delivery apparatus 50 applies a very thin layer of marker or organic pigment particles (and possibly a carrier such as a liquid solvent) on the surface of the image-bearing member 10. Figure 1 demonstrates an embodiment and an organic pigment delivery apparatus, wherein the housing 52 is adapted to accommodate a supply of organic pigment particles 54 and any additional carrier material, if necessary. In this embodiment, the organic pigment applicator 50 includes an applicator roller 56, which is rotated in the direction 57 to transport organic pigment from the housing 52 in contact with the surface 'of the image-bearing member 10. In this way , a layer of organic pigment distributed in a substantially uniform manner is formed on it 58, or a so-called "organic pigment bark". The organic pigment bark can be created in various ways, depending on the materials used in the printing process, as well as the other process parameters, such as the speed of the process and the like. Generally, a particle layer of organic pigment having a sufficient thickness (preferably, from about 2 to about 15 microns, and particularly preferably from about 3 to about 8 microns), may be formed on the surface of the member imager 10, transferring an ink crust of similar thickness and solids content to that of the applicator member 56. In a preferred embodiment, electrical deviation 55 may be employed to assist in actively moving the organic pigment crust of the applicator 56 onto the surface of the image-bearing member 10. In this embodiment, the organic pigment applicator 56 is provided with an electrical deviation of magnitude greater than that of the areas with images and without images (bottom) of the latent electrostatic image on the image-bearing member 10. Those electric fields cause the organic pigment particles to be transferred to the image-bearing member 10 to form a substantially uniform layer of organic pigment particles on the surface thereof. . In the case of liquid developer materials, it is desirable that the organic pigment shell formed on the surface of the image-bearing member 10 be comprised of at least about 10 weight percent organic pigment solids, and preferably in the range from about 15 to about 35 weight percent organic pigment solids. After the organic pigment layer 58 is formed on the surface of the image-bearing member 10, the organic pigment layer is loaded using the charging device 60 (which, in the embodiments, can be an scorotron device) in a shape across the width of the image. In the embodiments, the charging device 60 introduces freely moving ions in the vicinity of the charged latent image to facilitate the formation of the ion flux across the image extending from the source 60 to the latent image on the surface of the image-bearing member 10. The source of ions 60 should provide ions having a charge opposite to the polarity of the charge of the original organic pigment layer. In order to achieve good image quality, the charging member 60 is preferably provided with an energizing deviation in its grid intermediate the potential of the image areas and without latent image images on the imaging member 10. The ion flow across the image, it generates a secondary latent image in the organic pigment layer consisting of organic pigment particles with opposite charge in the image configuration corresponding to the original latent image. Once the secondary latent image is formed in the organic pigment layer, the organic pigment layer loaded across the image advances towards the image separator 20, which rotates in the direction 21. The image separator 20 can be provided in the form of a deviated roller member having a surface adjacent to the surface of the image-bearing member 10, and preferably in contact with the layer of organic pigment 58 that resides on the image-forming member 10. A source of deviation The electrical separator is coupled to the image separator 20. In the embodiments, as described in FIG. 1, the image separator 20 is deflected with a polarity opposite to the polarity of the loading of the imaged areas in the organic pigment layer 58. to attract the image areas of it. The developed image is constituted of separate and selectively transferred portions of the organic pigment shell on the surface of the image separator 20. The by-products of the background image are left on the surfaces of the image-bearing member 10. Alternatively, the image separator 20, may be provided with an electrical deviation having an appropriate polarity to attract non-image areas away from the image-bearing member 10. The portions of organic pigment corresponding to the areas with images on the surface of the image-bearing member they can be maintained by producing a revealed image about it. After the developed image is created, the developed image can then be transferred to a copy substrate 70 via the image separator 20, together with a hot member 80 or a non-hot press member. The by-product of the background image on any of the image-bearing members 10 is subsequently removed from the surface to clean the surface for the preparation of a subsequent imaging cycle. Figure 1 illustrates a knife cleaning apparatus 90. In the embodiment illustrated in Figure 1, the removed organic pigment is transported to an organic pigment collector or other recovery vessel, so that the discarded organic pigment can be recycled and used again.

The process for generating a secondary latent image in the organic pigment shell layer will be described in greater detail with respect to Figure 2, where the initially loaded organic pigment shell 58 is illustrated, for purposes of illustration only, as a distributed layer. uniformly of organic pigment particles negatively charged with the thickness of a single particle of organic pigment. The organic pigment shell resides on the surface of the imaging member 10 which is transported from left to right along the wide source ion charging device 60 .. As described above, the main function of the ion charging device of the wide source 60 is to provide free-moving ions in the vicinity of the image-bearing member 10 having the organic pigment layer and the latent image thereon. As such, the wide source ion device can be incorporated as several known devices, including, but not limited to, any of the known corona generating devices available in the art, as well as charging roller type devices, charging devices in solid state and sources of electrons or ions analogous to the type commonly associated with ionographic writing processes. In the particular embodiment shown in Figure 2, a corona generating device of the scorotron type was used. The scorotron device comprises a corona generating electrode 62 included within a shell member 64 surrounding the electrode 62 on three sides. A wire grid 66 covers the open side of the shell member 64 facing the image forming member 10. In operation, the corona generating electrode 62, otherwise known as a corona, is coupled to an electrical deviation source 63 capable of of providing a relatively high voltage potential to the corona, which causes electrostatic fields to develop between the corona 62 and the grid and the image carrying member 10. The strength of those fields causes the air immediately surrounding the corona to ionize , generating free-moving ions, which are repelled from the corona to the grid 66 and the image-bearing member 10. As is known to those skilled in the art, the scorotron grid 66 is deflected to operate to control the amount of loading and uniformity of the load applied to the image forming surface 10 by controlling the flow of ions through the electric field formed between the grid and the image forming surface. In one embodiment, an ion source energized by an AC voltage having an intermediate CD voltage deviation from the intermediate grid 66 to areas with images and without latent image images, represented by the signs (+) can be used. and (-), respectively, for loading the back side of the imaging member 10. As illustrated, positive ions flow from the ion source 60 in the direction of the field lines while the negative ions (electrons) flow in a direction opposite to the direction of the field lines so that the positive tones presented in the vicinity of a positively charged area of the latent image are repelled from the layer of organic pigment 58 while the positive ions in the vicinity of an area negatively charged the latent image are attracted to the layer of organic pigment, and captured by it. In contrast, negative ions presented in the vicinity of an area positively charged from the latent image are attracted to the image-bearing member 10 and absorbed in the negatively charged organic pigment 58, thereby increasing the charge of the organic pigment in that area, while negative ions in the vicinity of negatively charged areas of the latent image are repelled by the organic pigment layer. The freely flowing ions generated by the ion source 60 are captured by the organic pigment layer 58 in a form corresponding to the latent image on the image forming member, producing the load across the image of the organic pigment layer 58, thereby creating a secondary latent image within the organic pigment layer 58, which is charged with a polarity of charge opposite to the image charge latent original. Under optimal conditions, the charge associated with the original latent image will be captured and converted to the secondary latent image in the organic pigment layer 58, so that the original electrostatic latent image is substantially or completely dissipated towards the organic pigment layer 58. The subject matter of this modality is described in detail in U.S. Patent Application Serial No. 08 / 883,292 File No. D / 97135, filed on June 27, 1997, entitled "Description of the Latent Electrostatic Image", the description of which is incorporated here as a reference in its entirety. Alternative modalities may be employed to load the image-bearing member and create a secondary latent image. Figures 5 and 6 demonstrate two preferred alternative embodiments. It should be appreciated that the image separator of the present application can be • used with other contact electrostatic printing devices which employ the organic pigment shell as the developer material. Figure 5 demonstrates an alternative modality for forming a secondary latent image. The apparatus of Figure 5 is the same as that described in Figure 1, except that the ion source 60 was replaced with a deviated roller member 67 and a source of electric deflection 68. After the layer of air is formed. organic pigment 58 on the surface of the imaging member containing the latent electrostatic image 10, the organic pigment layer is loaded across the image inducing the ionization of air in the vicinity of the organic pigment layer on the forming member of images containing the latent electrostatic image 10. In this way, a deviated roller member 67, located adjacent the layer of organic pigment 58 on the imaging member 10, is provided to introduce ions that move freely in the vicinity of the latent image loaded to facilitate the formation of an ion flux across the image extending on the roller member 67 to the latent image on the surface of the image-carrying member 10. The flow of ions across the image generates a second latent image in the organic pigment layer 58 composed of organic pigment particles interposed in the image configuration corresponding to the latent image original generated on the image forming member 10. The main function of the deviated roller member 67 is to provide free-moving ions in the vicinity of the image forming member 10 having the layer of organic pigment 58 and the latent image thereon. It is known that when two conductors are kept close to one another with an applied voltage between the two, an electric shock will occur when the voltage increases to the point of air breaking. In this way, at a critical point, a discharge current is created in the air space between the conductors. This point is commonly known as the Paschen threshold voltage. When the conductors are very close (a few thousandths of an inch) a spark-free discharge can take place, so that both a discharge stream flows through a space between the roll member 67 and the organic pigment layer 58. present invention uses the exploitation of this phenomenon to induce load across the image. In operation, the deviated roller member 67 is coupled to a source of electrical deflection 68 capable of providing a voltage potential appropriate to the roller member, sufficient to cause the air to break in the vicinity of an imaging member that contains a latent image. Preferably, the voltage applied to the roller 67 is maintained at a predetermined potential, so as to induce an electric discharge only in a limited region where the surface of the roller member 67 and the image forming member 10 are in close proximity, and the voltage difference between the roller and the areas with images and / or without images of the latent image exceed the Paschen threshold voltage. In a preferred embodiment, which will be known as "one-way breaking", it was contemplated that the deviation applied to the roller 67 is sufficient to exceed the Paschen threshold voltage only with respect to any of the areas with images or without images of the original latent image on the image forming member. Alternatively, in another embodiment, the deviation applied to the roller 67 will be sufficient to exceed the Paschen threshold with respect to both areas with images or without images of the original latent image. It can be done that the disruption of the induced air in this situation occurs in such a way that the field lines are generated in opposite directions with respect to the areas with images and without images. For example, in the case where the Paschen threshold voltage is about 400 volts, and the imaged and non-image areas have voltage potentials of about 0 and -1200 volts, respectively, a deviation potential applied to the roll 67 of approximately -200 volts will result in a breakdown of the air that generates charges only in the region of the non-image areas, so that the organic pigment particles adjacent to this region will be affected. Conversely, a deviation of -1000 volts applied to the roller 67 will result in a charge generation in the area region with latent image images, with the ions flowing in the opposite direction. In still another alternative, a deviation of about -600 volts applied to the roller 67, will result in a generation of charge in the areas adjacent to both areas with images and without images, with the ions flowing in opposite directions. This so-called two-way air breaking mode occurs when a breakdown of the air is induced via an electrical discharge in a region before the contact point and immediately before a contact region created by contact between the image forming member 10. and the roller member 67. The electric discharge causes electrostatic fields to develop between the roller member 67 and the image forming member 10 in the precontact region. In addition, the force of the fields causes the air to be ionized, generating free-moving ions, which are directed towards the imaging member 10. The magnitude of the deflection potential applied to the roller member 67, operates to control the ionization across the image in the amount of charge and the uniformity of the load applied to the image forming surface 10. Thus, according to the example described above, the two-way air break can be induced by applying a deflection voltage to the roller 67, which is sufficient to exceed the Paschen threshold with respect to both areas with images and without images of a latent image on an image forming member brought into the vicinity of the roller 67. Whenever this deviation applied When the roller 67 is in an interval intermediate to the potential associated with the areas with images and without images, an appropriate control to the direction of the the flow of the charge to create the desired latent image in the organic pigment layer. The subject matter of this embodiment is described in detail in U.S. Patent Application Serial No. 08 / 884,236, File No. D / 97136, filed on June 27, 1997, entitled "Loading Organic Pigment Layers. to Form Images by Air Breaking for the Development of Images ", the description of which is incorporated herein as a reference in its entirety. In another embodiment of the invention, the secondary latent image is still formed in another way. The apparatus of Figure 6 differs from that of Figures 1 and 5 in that a load member 30 and an image display station 40 are absent. The support member of the exemplary organic pigment layer 10 in this embodiment may include a relatively thin surface layer 14, comprising a conductive material, an insulating material, a thin dielectric material, of the type known to those skilled in the art of ionography, a semiconductor material or other material that can be contemplated for use in a system of typical or other type of electrostatic image formation. The surface layer 14, can be supported on an electrically conductive support substrate, and preferably connected to ground 16. After the organic pigment layer 58 is formed on the surface of the image forming member containing the latent electrostatic image 10, the pigment layer Organic is loaded across the width of the image. In the case of a loaded organic pigment layer 58, as is the case in the systems of Figure 6, there is provided a loading device 69, shown schematically in Figure 6, as well as the well-known scorotron device, to introduce Ions that move freely in the vicinity of the charged latent image to facilitate the formation of an ion flux across the image extending from the source 69 towards the latent image on the surface of the image-bearing member 10 as will describe. The ion flux across the image generates a secondary latent image in the organic pigment layer composed of organic pigment particles composed in the image configuration corresponding to the latent image.

The bark of the organic pigment resides on the surface of the image forming member 10 which is transported from left to right along the wide source ion charging device 69. As described above, a main function of the ionic charge device Wide source 69 is to provide ions that move freely in the vicinity of the imaging member 10 having the organic pigment layer and the latent image therein. Therefore, the wide source ion device can be incorporated as several known devices, including, but not limited to, any of the various known corona generating devices available in the art, as well as charging roller type devices, devices of charge in solid state and sources of electrons or ions analogous to the type commonly associated with the processes of ionographic writing. In the case of a loaded organic pigment layer, the process of the present invention requires that the ion source 69 provide ions having a charge opposite to the polarity of the organic pigment charge. The description of this modality is described in detail in US Patent Application Serial No. 09 / 004,629, File No. D / 97546, filed on January 8, 1998, entitled "Loading Organic Pigment Layer to Reveal Images ", the description of which is incorporated here as a reference in its entirety. Figure 3 demonstrates one embodiment of an image separator. The image separator 20 in Figure 3 comprises the substrate 1 and the conformable layer 2. Further, Figure 3 demonstrates a preferred embodiment of the invention, wherein the substrate 1 comprises a conductive filler 4, and wherein the conformable layer 2 comprises the conductor filler 5. The conductive fillers 4 and 5 can be the same or different. Figure 4 demonstrates another embodiment of the image separator, where the image separator 20 comprises the substrate 1, the conformable layer 2 and the external peelable layer 3. Also described in Figure 4 are conductive fillers in each layer, where the substrate 1 it comprises the conductive filler 4, the conformable layer 2 comprises the conductive filler 5, and the external detachable layer 3 comprises a conductive filler 6. The conductive fillers 4, 5 and 6 can be the same or different. The conformable layer has a low modulus. The molding of the organic pigment on the surface of a porous or rough paper (or other substrate) facilitates complete transfer. The transfer of non-conformed materials to rough substrates is limited to contact points (high spot content on the paper surface) and results in poor image quality. The release layer provides such surface qualities that the organic pigment image moves through the process without being destroyed but is easily transferred to the paper. The organic pigment adheres poorly to the release materials resulting in degraded image quality and an excessive need for cleaning of the image separator. Therefore, a release layer facilitates the transfer of the organic pigment. The image separator can be of several configurations. Those configurations include a conformable layer placed on the substrate, where the substrate can be a band, sheet, film or roller. Also included as a suitable configuration is a conformable layer placed on the substrate, and placed on the conformable layer, an outer release layer. Again, the substrate may be in the form of a band, sheet, film or roll. The conformable layer may comprise a conformable conductive material, a conformable semiconductor material, or a combination of both. The outer displacement layer is preferably an insulating displacement layer, but can be any other suitable layer. In another configuration, an insulating layer can be placed on the conformable layer. In addition, there may be a suitable adhesive placed between the conformable layer and the substrate, and / or placed between the conformable layer and the outer release layer or thin insulating layer. In the web or sheet or film substrate configuration, the web can be sewn or not stitched. In the configuration where the substrate is a web, sheet, film or the like, preferred examples of suitable substrate materials include polyimides and polyamides such as PAI (polyamideimide), Pl (polyimide), polyaramide, polyphthala ida, fluorinated polyimides, polyimidosulfone , polyimide ether, and the like. Specific examples are set forth in U.S. Patent 5,037,587, the disclosure of which is incorporated herein by reference in its entirety. Other suitable materials for the substrate band include polyesters such as polyethylene naphthate; (PET); polyethylene terephthalate; polysulfone; polycarbonate; polyphenylene sulfide; polyketone; (PEEK) polyether ether ketone; (PES) polyethersulfone; PAEK (polyaryletherketone); PBA (polyparabanic acid); and similar. In another embodiment, the substrate may contain a fabric material such as a woven or non-woven fabric, knitted or felt fabric, or any other suitable fabric using natural or synthetic fibers. Fabric, as used herein, refers to a textile structure comprised of mechanically interlaced fibers or filaments, which may be woven or non-woven. Fabrics are materials made from fibers or threads and fabrics, woven by knitting or pressed into a garment or structures of the felt type. Woven, as used herein, means that it is oriented closely by the warp and weft threads at right angles to each other. Non-woven, as used herein, refers to randomly integrated fibers or filaments. Examples of such suitable include woven or non-woven cotton fabric, graphite cloth, glass fiber, woven or non-woven polyimide (for example KELVAR® available from DuPont), woven or non-woven polyamide, such as nylon or polyethylene isophthalamide (for example, NOMEX® from EI DuPont of Wilmington, Delaware), polyester, polycarbonate, polyacrylic, polystyrene, polyethylene, polypropylene, cellulose, polysulfone, polyxylene, polyacetal and the like. The details of such fibers useful as substrates are set forth in U.S. Patent Application No. 08 / 050,135, File No. 97684, filed on March 30, 1998, entitled "Film for Fabric Fusher", the description of which it is incorporated here as a reference in its entirety. The polymer used as a substrate in the band configuration can be filled or not filled. Examples of preferred fillers include carbon black fillers, metal oxides and polymer particles. Specific examples of fillers include carbon black, fluorinated carbon black, graphite and the like, and mixtures thereof; metal oxides such as indium tin oxide, zinc oxide, iron oxide, aluminum oxide, copper oxide, lead oxide, and the like, and mixtures thereof; mixed metal oxides such as tin oxide mixed with antimony, titanium dioxide mixed with antimony, zinc oxide mixed with aluminum, metal oxides mixed in a similar manner, and mixtures thereof; and polymer particles such as polypyrrole, polyaniline and the like, and mixtures thereof. Preferably, the filler, is present in the substrate, is present in an amount of from about 1 to about 40, preferably from about 2 to about 30% by weight of total solids. Preferably, the web substrate has a resistivity range of from about 103 to about 1013 ohm-cm, and preferably from about 10e to about 10 ohm-cm. It is preferred that the substrate be a flexible, sewn, endless band, and sewn flexible bands, which may or may not include combined cut seams. Examples of such bands are described in U.S. Patent Nos. 5,487,707; 5,514,436; and U.S. Patent Application Serial No. 08 / 297,203, filed on August 29, 1994, the description of each of which is incorporated herein by reference in its entirety. A method for manufacturing reinforced seamless webs is disclosed in U.S. Patent No. 5,409,557, the disclosure of which is incorporated herein by reference in its entirety. In the configuration where the substrate is in the form of a roller, the substrate may comprise a sturdy, robust plastic material, such as any of the materials shown above for the web configuration. Alternatively, the roller may comprise a metal, such as aluminum, nickel, stainless steel or similar. In other embodiments, the roller may comprise a fabric as discussed above. The conformable layer is preferably conformable enough to transfer the organic pigment image to rough papers. Preferably, the conformable layer has a thickness of about 0.001 (0.00254) to about 0.5 inch (1.27 centimeters), and preferably about 0.003 (0.00762) to 0.150 inches (0.381 centimeters). Preferably, the conformable layer has a hardness of about 30 to 70 Shore A units, preferably 50 to 60 Shore A units.

The conformable layer may comprise a conductive or semiconductor material. Suitable examples of conformable material include fluoropolymers, including TEFLON® and TEFLON®-like materials and fluoroelastomers; silicone materials, such as silicone rubbers, siloxanes, polydimethylsiloxanes and fluorosilicones, aliphatic or aromatic hydrocarbons, polyurethanes; nitrile rubbers, copolymers or terpolymers of the foregoing, and the like; and mixtures of those. The conductive or semiconductor material is present in an amount of from about 30 to about 99.5, and preferably from about 60 to about 90 percent by weight of the total solids. The fluoropolymer conformable layers particularly useful for the present invention include materials similar to TEFLON®) such as polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene copolymer (FEP), perfluorovinylalkyl-ethertetrafluoroethylene copolymer (TEFLON® PFA), copolymers thereof and the like . The examples also include such elastomers. as the fluoroelastomers. Specifically, suitable fluoroelastomers are those described in detail in U.S. Patent Nos. 5,166,031; .28.1,506; 5,366,772; 5,370,931; 4,257,699; 5,017,432 and 5,061,965, the descriptions of each of which are incorporated herein by reference in their entirety. These fluoroelastomers, particularly the class of the copolymers, terpolymers and tetrapolymers of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene and a possible monomer at the curing site, are commercially known under various designations such as VITON A®, VITON E®, VITON E60C®, VITON E430®, VITON 910®, VITON GH®, VITON GF®, VITON E45, VITON A201C, and VITON B50Q The designation VITON is a Trademark of EI DuPont de Nemours, Inc. Other materials commercially Available include FLUOREL 2170®, FLUOREL 2174®, FLUOREL 2176®, FLUOREL 2177®, FLUOREL 2123®, and FLUOREL LVS 76®, FLUOREL® being Trademarks of 3M Company. Additional commercially available materials include AFLASMR, a poly (propylene tetrafluoroethylene) and FLUOREL II (LII900) an elastomer of poly (propylene tetrafluoroethylene vinylidene fluoride), both also available from 3M Company. Also preferred are TECNOFLONS® identified as FOR-60KIR®, FOR-LHF®, NM® FOR-THF®, FOR-TFS®, TH®, and TN505®, available from Montedison Specialty Chemical Company.

In a preferred embodiment, the fluoroelastomer is one that has a relatively low amount of vinylidene fluoride, such as in VITON GF®, available from EI DuPont de Nemours, Inc. VITON GF has 35 weight percent vinylidene fluoride , 34 weight percent hexafluoropropylene and 29 weight percent tetrafluoroethylene with 2 weight percent monomer from the curing site. The curing site monomer may be one of those available from DuPont such as 4-bromoperfluorobutene-1,1-dihydro-4-bromoperfluorobutene-1,3-bromoperfluoropropene-1,1,1-dihydro-3-bromoperfluoro -propene-1, or any other suitable, known, commercially available monomer from the curing site.

The fluorine content of VITON GF® is approximately 70 by weight of the total weight of the fluoroelastomer. Other suitable fluoroelastomers include latex fluoroelastomers, such as those available from Lauren International and Aussimont. Examples of latex fluoroelastomers are disclosed in U.S. Patent Application Serial No. 09 / 024,269, in Attorney File No. D / 97081, filed on February 17, 1998, entitled "Filled Latex Fluorocarbon Elastomer Surfaces. with Fluorinated Carbon and Methods of the same ", the description of which is hereby incorporated as a reference in its entirety. These materials have the advantage of being aqueous dispersions, and therefore are friendly to the environment. Other suitable fluoroelastomers include compound fluoroelastomeric materials, which are hybrid polymers comprising at least two distinct systems, blocks or segments of polymeric monomers, wherein a monomeric segment (hereinafter referred to as a "first monomeric segment"), which possesses a high wear resistance and high hardness, and the other monomeric segment (hereinafter referred to as a "second monomeric segment"), which possesses low surface energy. The composite materials described herein are hybrids or polymeric compositions comprising interpenetrating, substantially uniform, integrated networks of a first monomeric segment and a second monomeric segment, and in some embodiments, optionally a third grafted segment, wherein both the structure and the composition of the segment networks are substantially uniform when viewed through different cuts of the separator member layer. The interpenetrating network in the embodiments refers to the addition polymerization matrix where the polymer strands of the first monomeric segment and the second monomeric segment, and the optional third grafted segment, are interwoven with each other. A polymeric composition, in the embodiments, is comprised of a first monomeric segment and a second monomeric segment, and a third optional grafted segment, where the monomeric segments are arranged randomly in a long chain molecule. Examples of polymers suitable for use as the first monomeric segment or the monomeric segment taught include, for example, polyamides, polyimides, polysulfones, and fluoroelastomers. Examples of low surface energy monomer segments or polymers of the second monomeric segment include polyorganosiloxanes, and include intermediates which form inorganic networks. An intermediate is a precursor for the inorganic oxide networks present in the polymers described herein. This precursor carries out the hydrolysis and condensation followed by the addition reactions to form the desired network configurations of, for example, metal oxide networks such as titanium oxide, silicon oxide, zirconium oxide and the like.; metal halide networks and metal hydroxide networks. Examples of intermediates include metal alkoxides, metal halides, metal hydroxides, and a polyorganosiloxane as defined above. Preferred intermediates are alkoxides, and especially preferred are tetraethoxy orthosilicate for the network of silicon oxide and titanium isobutoxide for the titanium oxide network. In the embodiments, a third monomeric segment of low surface energy is a grafted monomeric segment and, in the preferred embodiments, is a polyorganosiloxane as described above. In those preferred embodiments, it is particularly preferred that the second monomeric segment be an intermediate for a metal oxide network. Preferred intermediates include tetraethoxy orthosilicate for the silicon oxide network and titanium isobutoxide for the titanium oxide network. Examples of suitable polymeric compositions include volume grafted elastomers, titmers, grafted titmers, ceramics, grafted cerammers, polyamide and polyorganosiloxane copolymers, polyimide and polyorganosiloxane copolymers, polyester and polyorganosiloxane copolymers, polysulfone and polyorganosiloxane copolymers, and the like. The grafted titomers and titmers are described in U.S. Patent 5,486,987; grafted ceramers and cerammers are described in U.S. Patent 5,337,129; and volume grafted fluoroelastomers are described in U.S. Patent 5,366,772. In addition, these fluoroelastomer composite materials are described in U.S. Patent 5,778,290. The descriptions of those patents are incorporated herein by reference in their entirety.

Other elastomers suitable for use herein include silicone rubbers. Suitable silicone rubbers include vulcanization room temperature silicone rubbers (RTV); high temperature vulcanization silicone rubber (HTV) and low temperature vulcanization silicone rubber (LTV). Specific examples of suitable silicone rubbers include Rhodorsil® from Rhone Poulenc (with the crosslinking agent Silbond 40 (ethyl silicate), the curing agent Fascat® 4200 (dibutyl tin diacetate)). Other conformable materials suitable for the conformable layer include polyurethanes such as BAYHYDROL® 121 (Bayer), nitrile rubber, and the like. The conformable layer can be filled or not filled with a suitable conductive filler. Preferred conductive fillers for addition to the conformable material include carbon black, metal oxides and polymer particles. Preferably, the fillers include carbon black such as Black Pearls ® 2000, fluorinated carbon such as those sold under the trademark ACCUFLUOR, graphite, and the like, and mixtures thereof; metal oxides such as indium tin oxide, zinc oxide, iron oxide, aluminum oxide, ferric oxide, ferrous oxide, copper oxide, lead oxide and the like, and mixtures thereof; mixed metal oxides such as tin oxide mixed with antimony, titanium dioxide mixed with antimony, zinc oxide mixed with aluminum, metal oxides mixed in a similar manner, and mixtures thereof; polymeric particles such as polypyrrole, polyaniline and the like, and mixtures thereof. The conductive filler, if present in the conformable layer, is preferably present in an amount of from about 2 to about 40 percent, and preferably from about 5 to about 12 percent by weight of total solids. These intervals depend on the quality of the dispersion and the conductivity of the filler. An outer release layer may be present on the conformable layer. The outer release layer may comprise a polymer such as a fluoropolymer or a silicone rubber. Examples of suitable fluoropolymers include TEFLON-like materials such as those listed herein, and other low surface energy polymers and elastomers. Materials similar to TEFLON are preferred, and materials such as silicones absorb some of the liquid organic liquid carrier fluid and thus form a weak boundary. The release layer may or may not comprise fillers. If a filler is present, the filler is present in the same amounts set forth above for the conformable layer. Examples of suitable fillers include those listed for the conformable layer. The outer release layer may comprise the same materials as the conformable layer. The thin outer layer has a thickness of a monolayer having a thickness of about 0.01 to about 0.1 inches (0.0254 to about 0.254 cm), preferably from about 0.02 to about 0.05 inches (0.0508 to about 0.127 cm). Suitable adhesives may be present between the substrate and the conformable layer, and between the conformable layer and the optional external release layer. The choice of adhesive will depend on the composition of the layer or layers to be joined. A particularly preferred image separator comprises a polyimide substrate, an adhesive, and a conformable silicone layer with carbon black conductive filler and without an external release layer. Another preferred embodiment comprises a polyimide substrate, adhesive, a conformable layer of fluoroelastomer (such as VITON® GF) with carbon black filler, adhesive, and an outer release silicone layer. The image separator can be made by known processes including the application of the conformable layer and / or the release layers by spray coating, flow coating, stretching by means of a groove and similar methods. The invention will now be described in detail with respect to the preferred embodiments thereof, it should be understood that those examples are intended to be illustrative only of the invention and are not intended to be limited to the materials, conditions or process parameters set forth herein. All percentages and parts are by weight unless otherwise indicated.

Example 1 Preparation of the Conformable Layer in a Carrier Member of Images A conformable layer for an image carrier member used in an electrostatic contact apparatus, such as one of the apparatuses described herein, has been prepared as follows. A 3-mil (76.2 μm) thick polyimide conductive substrate from DuPont was purchased. An adhesive (Dow Corning A4040 primer) was spray coated onto the polyimide substrate. a coating of conformable layer mixing silicone rubber (Rhodorsil from Rhone Poulenc) in an amount of about 65 weight percent total solids with 9 percent by weight of total solids of crosslinker ethyl silicate (Silbond 40 was prepared ), and 6 percent by weight of total carbon black solids (Black Pearls 2000). The carbon black was dispersed in the mixture by grinding the mixture in a ceramic container with 3,000 g of 0.5 inch (1.26 cm) ceramic bales for approximately 48 hours. The dispersion was filtered. Subsequently, about 20 weight percent of total solids of dibutyltin diacetate curing agent (Fascat 4200) were added by stirring. The solution was then applied to the polyimide substrate with adhesive on it, the process of spray coating, slot stretching and flow coating. The coating was air dried for 15 minutes, and cured by the hot curing step at temperatures ranging from about 90 to about 450 ° F (32.22 to about 232.22 ° C) for about 12 hours. The resulting conformable coating was 0.003"(0.000762 cm) thick. The freshly prepared image carrying member tested in an apparatus electrostatic contact printing prototype, and showed excellent definition image without background. Efficiency transfer was demonstrated to 100 percent, and the quality of the resulting print was higher with the high level of desired brightness. in addition, the configuration had the additional benefit of absorbing the carrier of images LID thereby providing conditioning of the image It was found that the bending life was 300,000 cycles and the type of provisional assembly exceeded 1,000 cycles.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Claims (24)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. An electrostatic contact printing apparatus, characterized in that it comprises: (a) an image carrier member comprising a developed image, wherein the developed image comprises a primary latent image and a secondary latent image; and (b) an image separator comprising the secondary latent image, wherein the image separator comprises: (i) a substrate; and on it (ii) a conformable layer comprising a conductive or semiconducting polymer; and (iii) an optional external release layer placed on the conformable layer.

2. The image separator according to claim 1, characterized in that the conformable layer comprises a polymer selected from the group consisting of silicone rubber, fluoropolymers, polyurethanes and nitrile rubbers.

3. The image separator according to claim 2, characterized in that the conformable layer comprises silicone rubber. .

The image separator according to claim 2, characterized in that the conformable layer comprises a fluoropolymer selected from the group consisting of (a) copolymers of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, (b) terpolymers of vinylidene fluoride, hexafluoropropylene and Tetrafluoroethylene, and (c) tetrapolymers of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene and a monomer of the curing site.

5. The image separator according to claim 2, characterized in that the conformable layer It comprises a fluoropolymer composition comprising a first monomeric segment, a second monomeric segment, and a third optional monomeric segment, and wherein the composition is an integrated, substantially uniform, interpenetrating network of the first monomeric segment and the second monomeric segment. , and optionally the third monomeric segment.

The image separator according to claim 5, characterized in that the fluoropolymer composition is selected from the group consisting of a volume-grafted haloelastomer, a titanium, a grafted titanomer, a ceramomer, a grafted cermer, a polyimido polyorganosiloxane, and a polyorganosiloxane polyester.

The image separator according to claim 1, characterized in that the conformable layer comprises a conductive filler.

The image separator according to claim 7, characterized in that the filler is selected from the group consisting of carbon black, graphite, metal oxide, polymer particles and mixtures thereof.

9. The image separator according to claim 8, characterized in that the filler is a metal oxide selected from the group consisting of aluminum oxide, ferric oxide, ferrous oxide, indium tin oxide, zinc oxide, copper, lead oxide and mixtures thereof.

The image separator according to claim 8, characterized in that the filler is a mixed metal oxide selected from the group consisting of tin oxide mixed with antimony, titanium dioxide mixed with antimony and zinc oxide mixed with aluminum.

The image separator according to claim 8, characterized in that the filler is selected from the group consisting of graphite, carbon black, fluorinated carbon black and mixtures thereof.

12. The image separator according to claim 1, characterized in that the substrate is of a band or roller shape.

The image separator according to claim 12, characterized in that the image separator is in the form of a band.

The image separator according to claim 13, characterized in that the band comprises a material selected from the group consisting of polyimide, polyamide, polyester, polysulfone, polycarbonate, polyphenylene sulfide, polyether ether ketone, and mixtures thereof.

15. The image separator according to claim 14, characterized in that the band comprises polyimide.

16. The image separator according to claim 12, characterized in that the substrate is in the form of a roller.

The image separator according to claim 16, characterized in that the roller comprises a material selected from the group consisting of aluminum, nickel, stainless steel and plastic.

18. The image separator according to claim 1, characterized in that an external peelable layer is placed on the conformable layer.

19. The image separator according to claim 18, characterized in that the release layer is a material selected from the group consisting of fluoropolymers and silicone rubbers.

The image separator according to claim 18, characterized in that the peelable layer comprises a conductive filler selected from the group consisting of carbon black, metal oxides, polymeric particles and mixtures thereof.

21. The image separator according to claim 1, characterized in that the image separator has a resistivity of about 103 to about 1013 ohm-cm.

22. The image separator according to claim 1, characterized in that it further comprises an electrical deviation connected thereto.

23. The image separator according to claim 1, characterized in that the conformable layer has a thickness from about 0.001 to about 0.5 inch (0.00254 to about 1.26 cm).

24. An electrostatic contact printing apparatus, characterized in that it comprises: (a) an image carrier member comprising a developed image, wherein the developed image comprises a primary latent image and a secondary latent image; and (b) an image separator comprising the secondary latent image, wherein the image separator comprises: (i) a substrate; and on it (ii) a conformable layer comprising a polymer selected from the group consisting of silicone rubbers, fluoropolymers, polyurethanes and nitrile rubbers, and comprising a filler selected from the group consisting of metal oxides, carbon black, polymer particles and mixtures thereof and a secondary image; AND (iii) an optional external release layer placed on the conformable layer.