Laminate for electrostatic printing

Abstract

To solve problems that when continuous production (roll-to-roll system) is performed by an electrostatic printing method, if a laminate for electrostatic printing is wound without performing image development, an electrode of an image receiving sheet comes into contact with an electrostatic pattern and the electrostatic pattern is lost, the electrostatic pattern formation and image development therefore need to be continuously performed, which deteriorates production efficiency as speed of continuous production is restricted by a process requiring more time; and to improve the efficiency of continuous production by performing electrostatic pattern formation and image development as independent processes.SOLUTION: A laminate for electrostatic printing is developed, on which an insulation layer (and release layer) is stacked on one surface and a backing layer is stacked on an opposite surface so as to sandwich a conductive layer and includes a conductive layer exposing part which is electrically connectable to either one of an insulation layer surface side and a backing layer surface side at one end or both ends in a width direction (Transverse Direction). The laminate for electrostatic printing is maintained as it is after the electrostatic pattern is formed even when wound in a roll shape without change in electrostatic pattern on the laminate for electrostatic printing. As a result, the electrostatic pattern formation and the image development can be performed independently as separate processes to improve production efficiency of the continuous production.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an electrostatic printing laminate used in electrostatic printing on an insulating layer. [Background technology]

[0002] The world's first practical technology for creating images using static electricity was invented by Chester Carlson of the United States. The technology related to this invention was commonly known as the Carlson method or xerography, but as academic research into it as an image formation technology progressed, it came to be known scientifically as electrophotography, and in Japan as electrophotography. Copiers and printers made using this technology have become indispensable for office work.

[0003] As the name "photography" suggests, this technology uses static electricity and a photosensitive material (optical semiconductor) to create an electrostatic latent image, which is then developed with charged particles called toner. It developed into a technology ideal for copiers, which instantly print and output images that change from page to page. The greatest advances in this technology are likely to be in the toner and development technologies used as the developer. Powder toner has been finely divided to approximately 6 μm, achieving uniform particle size and uniform charge, improving resolution and transfer stability. Furthermore, finely divided liquid toner has reached submicron size, ensuring developer stability and even surpassing printing ink in terms of resolution. Furthermore, functional toners and development methods, both powder and liquid, are being developed one after another, including not only color toners but also toners containing metals, development methods using metals themselves, and toners capable of plating, as shown in Patent Document 2.

[0004] However, electrophotography has limitations when it comes to fully utilizing the features of these functional toners. This is due to the fundamental element of creating an electrostatic pattern on the photoreceptor. In other words, the electrostatic pattern on the photoreceptor must be developed, and the developed toner must be transferred to the target material. Of course, this method is what makes plateless, high-resolution, high-speed printing possible, but the transfer process inevitably results in a decrease in resolution, and conductive toners can only be transferred by adhesion. Furthermore, current photoreceptors have analog characteristics, making it difficult to accurately print 10 μm dots and lines and dots and lines of 100 μm or more simultaneously at high speed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-19272 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-134422 [Non-patent literature]

[0006] [Non-Patent Document 1] Jono, Tanaka, Inoue, and Tajima: Journal of the Institute of Electrophotography, Vol. 17, No. 3, p. 2. Summary of the Invention [Problem to be solved by the invention]

[0007] Various attempts have been made in the past to directly develop electrostatic patterns. One such commercial product is the electrostatic transfer system, which transfers and directly develops the electrostatic pattern itself from a photoreceptor, as shown in Non-Patent Document 1. However, due to the special nature of the transfer paper and the principle that the electrostatic pattern is created by the peeling discharge action, the resolution is lower than that of the pattern on the photoreceptor, and this system is no longer manufactured. Devices that directly draw electrostatic patterns, such as multi-stylus and ion beam deflection systems, have been commercialized, but they have been replaced by inkjet systems due to limitations in electrode processing precision and low resolution caused by the spread of discharge ions. Furthermore, in Patent Document 1, which is a method for forming an electrostatic pattern for an electrostatic actuator, a partition is provided around the electrode to limit the discharge range, thereby achieving fidelity of the electrostatic pattern to the electrode. However, the method in Patent Document 1 cannot create image patterns like those in printing or electrophotography. Combining high-resolution electrostatic patterns with ever-evolving toners offers the possibility of printing with unprecedented effects and performance, and there is a need for a method to create high-resolution electrostatic patterns directly on insulating materials other than photoconductors.

[0008] Therefore, the inventors have proposed a practical high-resolution electrostatic printing method that uses static electricity to create images that are comparable to, or even surpass, conventional printing without using a photoreceptor (see the specification of Patent Application No. 2018-188998). According to a first aspect of the above invention, there is provided a high-definition electrostatic printing method, characterized in that an original plate is composed of a first electrode having uniform conductivity over its entire surface and a printing layer made of a material of appropriate uniform thickness that is intimately attached to and integral with the first electrode, and on which a relief, intaglio, or gravure-like pattern is formed in the printing layer, and an image receiving sheet is attached to the original plate, the back side of which is integrated with a conductive layer that serves as a second electrode; and an appropriate voltage sufficient to discharge the voids in the relief, intaglio, or gravure-like pattern is applied between the first electrode of the original plate and the second electrode of the image receiving sheet, thereby forming an electrostatic pattern on the image receiving sheet that corresponds to the relief, intaglio, or gravure-like pattern. In addition, according to a second aspect of the above invention, there is provided a high-definition electrostatic printing method, characterized in that an original plate is composed of a first electrode having uniform conductivity over its entire surface and a printing layer made of a material of appropriate uniform thickness that is in close contact with and integrated onto the first electrode, and on which a relief, intaglio, or gravure-like pattern is formed in the printing layer, and an image receiving sheet is pressed from the back side with a conductive second electrode, and an appropriate voltage sufficient to discharge the voids in the relief, intaglio, or gravure-like pattern is applied between the first electrode and the second electrode of the original plate, thereby forming an electrostatic pattern on the image receiving sheet corresponding to the relief, intaglio, or gravure-like pattern.

[0009] Furthermore, the present inventors proposed a continuous production method (roll-to-roll method) for the above invention. In this method, an image-receiving sheet is unwound from a roll and unfolded into a strip, and then pre-charged, an electrostatic pattern is formed by applying a voltage, and the electrostatic pattern is developed. The reason for developing the electrostatic pattern after forming the electrostatic pattern by applying a voltage is that if the image-receiving sheet is wound up without development, the electrostatic pattern will come into contact with the second electrode on the image-receiving sheet and be lost. However, since the time required for forming the electrostatic pattern by applying a voltage is short and the time required for developing the electrostatic pattern is long, the speed of continuous production in the above invention is limited by the time-consuming process, and the efficiency of continuous production in the above invention cannot be said to be high. If the electrostatic pattern formation by applying a voltage and the development of the electrostatic pattern could be performed as independent processes, production efficiency could be improved. There is a need to improve the efficiency of continuous production by performing these two processes independently. [Means for solving the problem]

[0010] The present inventors have developed a new laminate for electrostatic printing that allows for the formation of an electrostatic pattern by applying a voltage and the development of the electrostatic pattern to be carried out as separate processes. That is, the present invention provides a laminate for electrostatic printing that solves the above-mentioned problems. (I) A laminate for electrostatic printing, characterized in that an insulating layer is laminated on one side and a backing layer is laminated on the other side, sandwiching a conductive layer, and that at one or both ends in the transverse direction, there is an exposed portion of the conductive layer that can be electrically connected on either the insulating layer side or the backing layer side, and that an electrostatic pattern can be formed on the insulating layer. (II) A laminate for electrostatic printing, characterized in that an insulating layer and a release layer are laminated in this order on one side of the conductive layer, and a backing layer is laminated on the other side, and that at one or both ends in the transverse direction, an exposed portion of the conductive layer is electrically connectable to either the insulating layer side or the backing layer side, and that an electrostatic pattern can be formed on the release layer. (III) The laminate for electrostatic printing according to item 1 or 2, wherein the exposed portion of the conductive layer has a width of 1 to 100 mm. (IV) The electrostatic printing laminate according to item 1, 2 or 3, characterized in that the insulating layer and / or the backing layer are made of a molded product such as polyimide, polycarbonate, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), cycloolefin polymer, cycloolefin copolymer, fluorine-based resin, etc. [Effects of the Invention]

[0011] In the electrostatic printing laminate of the present invention, after forming an electrostatic pattern by applying a voltage, the electrostatic pattern on the electrostatic printing laminate is maintained unchanged even when the electrostatic printing laminate with the formed electrostatic pattern is wound up into a roll as is. As a result, it becomes possible to perform the formation of an electrostatic pattern by applying a voltage and the development of the electrostatic pattern as separate processes, improving the production efficiency of continuous production (roll-to-roll system). [Brief explanation of the drawings]

[0012] [Figure 1-A] Electrostatic printing laminate S [Figure 1-B] Electrostatic printing laminate S [Figure 1-C] Electrostatic printing laminate S [Figure 1-D] Electrostatic printing laminate S [Figure 2-A] Electrostatic printing laminate S [Figure 2-B] Electrostatic printing laminate S [Figure 2-C] Electrostatic printing laminate S [Figure 2-D] Electrostatic printing laminate S [Figure 3] Electrostatic pattern formation process using the electrostatic printing laminate S shown in Figure 1-A [Figure 4] Electrostatic pattern formation process using electrostatic printing laminate S shown in Figure 2-A [Figure 5] Toner image on electrostatic printing laminate S of Figure 1-A [Figure 6]Metal image formed by electroless plating process [Figure 7] Toner image on electrostatic printing laminate S in Figure 2-A [Figure 8] Toner image transfer process onto any substrate T [Figure 9] Metal layer coating process [Figure 10] Metal image formed by lift-off process DETAILED DESCRIPTION OF THE INVENTION

[0013] Figures 1-A, 1-B, 1-C, and 1-D show an example of the configuration of the electrostatic printing laminate S of the present invention and the state in which an electrostatic pattern is formed and maintained on the insulating layer 12 of the electrostatic printing laminate S. 1-A and 1-B has an insulating layer 12 on one side and a backing layer 14 on the other side via an adhesive layer 15, sandwiching a conductive layer 11 that becomes an electrode in the electrostatic pattern formation process, and has an electrically connectable exposed conductive layer portion 16 on the side of the backing layer 14. The exposed conductive layer portion 16 is provided at one or both ends of the electrostatic printing laminate S in the transverse direction. 1-C and 1-D has an insulating layer 12 laminated on one side via an adhesive layer 15 and a backing layer 14 laminated on the other side, sandwiching a conductive layer 11 that becomes an electrode in the electrostatic pattern formation process, and has an electrically connectable conductive layer exposed portion 16 on the insulating layer 12 side. The conductive layer exposed portion 16 is provided at one or both ends of the electrostatic printing laminate S in the transverse direction.

[0014] Figures 2-A, 2-B, 2-C, and 2-D show another example of the configuration of the electrostatic printing laminate S of the present invention and the state in which an electrostatic pattern is formed and maintained on the release layer 13 of the electrostatic printing laminate S. 2-A and 2-B, the electrostatic printing laminate S has an insulating layer 12 and a release layer 13 laminated in this order on one side, sandwiching a conductive layer 11 that becomes an electrode in the electrostatic pattern formation process, and a backing layer 14 laminated on the other side via an adhesive layer 15, and has an electrically connectable exposed conductive layer portion 16 on the side of the backing layer 14. The exposed conductive layer portion 16 is provided at one or both ends of the electrostatic printing laminate S in the transverse direction. 2-C and 2-D has an insulating layer 12 and a release layer 13 laminated in this order on one side via an adhesive layer 15, and a backing layer 14 laminated on the other side, sandwiching a conductive layer 11 that becomes an electrode in the electrostatic pattern formation process, and has an electrically connectable conductive layer exposed portion 16 on the insulating layer 12 side. The conductive layer exposed portion 16 is provided at one or both ends of the electrostatic printing laminate S in the transverse direction.

[0015] 1-A, 1-B, 1-C, and 1-D, a toner image is formed on the insulating layer 12 by developing an electrostatic pattern on the insulating layer 12 of the electrostatic printing laminate S. A metal image is formed on the insulating layer 12 by subjecting the toner image on the insulating layer 12 to electroless plating or lift-off processing. After the metal image is formed, the backing layer 14 can be separated from the electrostatic printing laminate S in response to requirements such as thinning.

[0016] In the electrostatic printing laminate S of Figures 2-A, 2-B, 2-C, and 2-D, a toner image is formed on the release layer 13 by developing the electrostatic pattern on the release layer 13 of the electrostatic printing laminate S. The toner image on the release layer 13 can be transferred onto any substrate T. A metal image is formed on the substrate T by subjecting the toner image on the substrate T to electroless plating or lift-off processing.

[0017] To facilitate the transfer of the toner image on the electrostatic printing laminate S of Figures 2-A, 2-B, 2-C, and 2-D to any substrate T, a release layer 13 is provided on the insulating layer 12. A thin film of a silicone resin, a fluorine resin, an olefin resin, a melamine resin, or the like formed by a coating method or the like can be used as the release layer 13. The thickness of the release layer 13 is preferably 0.03 to 0.4 μm.

[0018] The insulating layer 12 and backing layer 14 of the electrostatic printing laminate S shown in Figures 1-A, 1-B, 1-C, 1-D, 2-A, 2-B, 2-C, and 2-D must have high electrical insulation properties in order to retain the electrostatic pattern. Molded materials such as polyimide, polycarbonate, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), cycloolefin polymer, cycloolefin copolymer, and fluorine-based resin can be used as the insulating layer 12 and backing layer 14. The thicknesses of the insulating layer 12 and the backing layer 14 are preferably 5 μm or more, more preferably 10 μm or more, to maintain the electrostatic pattern. However, it is preferable to appropriately determine the thickness of each layer so that the total thickness of the electrostatic printing laminate S is within the range of 20 to 200 μm. If the total thickness of the electrostatic printing laminate S is less than 20 μm, handling becomes difficult. Furthermore, if the total thickness of the electrostatic printing laminate S exceeds 200 μm, the rigidity becomes too high, making it difficult to apply a roll-to-roll production method. Furthermore, in the case of the electrostatic printing laminate S shown in Figures 2-A, 2-B, 2-C, and 2-D, if the total thickness of the electrostatic printing laminate S exceeds 200 μm, it becomes difficult to closely contact the toner image on the release layer 13 of the electrostatic printing laminate S with any substrate T and perform toner transfer.

[0019] The conductive layer 11 only needs to serve to supply an electric field in the electrostatic pattern formation process or to stabilize the charge on the insulating layer 12 or the release layer 13, and therefore may be made of any conductive material, such as metal, conductive oxide, carbon, graphite, or conductive polymer. The electrostatic printing laminate S has an insulating layer 12 (or insulating layer 12 and release layer 13) on one side and a backing layer 14 on the other side, with a conductive layer 11 sandwiched between them. 1A, 1B, 2A, and 2B show an example in which a backing layer 14 is laminated via an adhesive layer 15 on a conductive layer 11 provided on an insulating layer 12. In this case, the backing layer 14 has an exposed conductive layer portion 16 on its surface that can be electrically connected. 1-C, 1-D, 2-C, and 2-D show an example in which an insulating layer 12 (or an insulating layer 12 and a release layer 13) is laminated via an adhesive layer 15 on a conductive layer 11 provided on a backing layer 14. In this case, an electrically connectable exposed conductive layer portion 16 is provided on the surface side of the insulating layer 12 (or the insulating layer 12 and the release layer 13). The conductive layer exposed portion 16 is preferably 1 mm or more in width to ensure stable electrical connection, and more preferably 3 mm or more in width. Conversely, if it is too wide, the effective width becomes narrow, so it is preferably 100 mm or less in width. The conductive layer exposed portion 16 can be provided at two or more locations on one end in the transverse direction of the electrostatic printing laminate S. In this case, the total width of the two or more locations is preferably 100 mm or less. The conductive layer 11 can be formed on the insulating layer 12 or the backing layer 14 by sputtering a metal film, a conductive oxide film, etc., coating a conductive polymer film, etc., or laminating a metal foil.

[0020] Below, we will describe an example of forming a metal image using the electrostatic printing laminate S of Figure 1-A and the electrostatic printing laminate S of Figure 2-A. In both cases, the thickness of the insulating layer is 25 μm and the thickness of the backing layer is 50 μm. An example of an electrostatic pattern formation process using the electrostatic printing laminate S of Figure 1-A is shown in Figure 3. An example of an electrostatic pattern formation process using the electrostatic printing laminate S of Figure 2-A is shown in Figure 4. These methods are applications of the high-resolution electrostatic printing method proposed by the present inventors (see the specification of Japanese Patent Application No. 2018-188998). An original plate 20 having a plate layer 22 on which a relief, intaglio, or gravure-like pattern is formed (Figures 3 and 4 show an example in which the area where a toner image is formed is intaglio) and an electrode 21 is used, and an electrostatic printing laminate S is used.The plate layer 22 of the original plate 20 is closely attached to the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S, and an appropriate voltage sufficient to discharge the gap between the pattern of the plate layer 22 and the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S is applied between the electrode 21 of the original plate 20 and the conductive layer 11 via the exposed conductive layer portion 16 of the electrostatic printing laminate S, thereby forming an electrostatic pattern corresponding to the pattern of the plate layer 22 on the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S.

[0021] The conditions under which a gap discharges can be calculated using Paschen's law. The discharge inception voltage for gaps of 8 μm or more can be expressed as a straight line, and is approximated by the following formula, where gap: d (μm) and gap discharge inception voltage: Vb. Vb=312+6.2d (1) The gap between the pattern of the printing layer 22 and the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S is 20 μm, and the discharge start voltage is 436 V. In other words, when an external voltage of 436 V or more is applied to the gap, a discharge occurs and ions are generated. The generated ions follow the electric field, with positive ions moving toward the negative electrode and negative ions moving toward the positive electrode. The ions charge the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S, which acts to weaken the electric field in the gap. The discharge ends when the voltage applied to the gap reaches the discharge start voltage of 436 V.

[0022] In the examples shown in Figures 3 and 4, the insulating layer 12 of the electrostatic printing laminate S is made of PET with a thickness of 25 μm and a dielectric constant of 3.2. This corresponds to an air thickness of 25 ÷ 3.2 = 7.8. The release layer 13 of the electrostatic printing laminate S is less than 0.5 μm thick and therefore virtually negligible. In this example, the entire surface of the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S is pre-charged at +300 V. This pre-charging ensures that the electrostatic printing laminate S adheres securely to the master plate 20. With the plate layer 22 and the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S in close contact, the conductive layer 11 is grounded via the exposed conductive layer portion 16, and a voltage of -723 V is applied to the electrode 21. The voltage applied to the 20 μm air gap is (723 + 300) × 20 ÷ (20 + 7.8) V = 736 V. Because this voltage is greater than the discharge inception voltage of 436 V for a 20 μm gap obtained from equation (1), discharge ions are generated in the gap. Negative ions migrate toward the conductive layer 11 and charge the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S, while positive ions flow to the electrode 21. When the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S is charged to -(736 - 436) = -300 V, the electric field applied to the gap reaches the discharge inception voltage of 436 V, and the discharge stops. After that, the applied power is turned off, the electrode 21 is set to 0 V, and the electrostatic printing laminate S is peeled off from the master 20. This creates an electrostatic pattern on the insulating layer 12 (or release layer 13) of the electrostatic printing laminate S, where the areas corresponding to the gaps in the intaglio plate (where the toner image is formed) are charged to -300 V and the other areas are charged to +300 V. The electrode 21 is set to 0V before peeling in order to provide a condition in which no peeling discharge occurs anywhere on the entire surface.

[0023] After forming the electrostatic pattern by applying the voltage, the electrostatic printing laminate S on which the electrostatic pattern was formed was wound into a roll. In the subsequent development process, it was confirmed that the electrostatic pattern on the electrostatic printing laminate S, which was pulled out from the roll and developed into a strip, was maintained unchanged.

[0024] Regarding the processes after the development step, we will first describe an example using the electrostatic printing laminate S shown in Figure 1-A. The electrostatic pattern on the insulating layer 12 of the electrostatic printing laminate S shown in Figure 1-A is developed with platable charged particles called toner, forming a platable toner image 30 on the insulating layer 12. Figure 5 shows an example of a platable toner image 30 formed on the insulating layer 12. The electrophotographic liquid toner proposed by the present inventors can be used as the platable charged particles (see Japanese Patent Application No. 2019-209237). Liquid toner is advantageous over dry toner in forming high-resolution toner images. This toner contains a resin with functional groups that function as ligands, capable of incorporating metals to form complexes. Examples of such functional groups include amino groups, carboxyl groups, hydroxyl groups, and thiol groups. The toner image 30 formed on the insulating layer 12 by development has the ability to adsorb catalytic metals or catalytic metal ions.

[0025] Figure 6 shows the electroless plating process. By immersing the substrate in a solution containing a catalytic metal, the catalytic metal is deposited only on the toner image 30, imparting catalytic activity. If the catalytic metal is adsorbed as an ion, an additional process of reducing it with hypophosphorous acid or formalin may be necessary depending on the situation. Examples of catalytic metals include palladium, copper, gold, and platinum. After the toner image 30 is given catalytic activity, the toner image 30 is subjected to electroless plating treatment, thereby forming a metal image 50 on the toner image 30 . In the example of FIG. 6, the electrostatic printing laminate S of FIG. 1A on which the toner image 30 was formed was treated with the following catalytic ability imparting liquid, electroless nickel plating bath or electroless copper plating bath.

[0026] [Catalytic activation solution, electroless nickel plating bath and electroless copper plating bath] The composition of the catalytic activity imparting solution is shown in the table below. TIFF2025146545000001.tif68118The composition of the electroless nickel plating bath is shown in the table below. TIFF2025146545000002.tif42118The composition of the electroless copper plating bath is shown in the table below. TIFF2025146545000003.tif50118

[0027] The electrostatic printing laminate S on which the toner image 30 was formed was immersed in the catalytic ability imparting liquid at 40° C. for 5 minutes, and then washed with water at room temperature for 1 minute to impart catalytic ability to the toner image 30. Next, the electrostatic printing laminate S was immersed in an electroless nickel plating bath at pH 8.0 and 70° C. for 10 minutes, and then washed with water to form a nickel image 50 on the toner image 30 . Alternatively, the electrostatic printing laminate S was immersed in an electroless copper plating bath at 25° C. for 12 minutes, and then washed with water at room temperature for 1 minute, thereby forming a copper image 50 on the toner image 30 . The nickel image and copper image formed on the electrostatic printing laminate S both had a thickness of 0.5 μm and a line width of 10 μm.

[0028] If necessary, the metal image formed by electroless plating may be subjected to electroplating to laminate the same or a different metal on the metal image, which can improve the strength, conductivity, and other properties of the entire metal image, including the metal laminate portion.

[0029] Next, regarding the processes after the development process, an example using the electrostatic printing laminate S of FIG. 2A will be described. The electrostatic pattern on the release layer 13 of the electrostatic printing laminate S of FIG. 2A is developed with charged particles called toner, forming a toner image 40 on the release layer 13. FIG. 7 shows an example of a toner image 40 formed on the release layer 13. In the example using the electrostatic printing laminate S of FIG. 2A, the toner image 40 must be removed along with the metal layer on top of it in the final step of the lift-off process. The resin that makes up the toner and the material of the removal solution (alkaline aqueous solution or organic solvent) are selected based on their combination. For example, if the resin that makes up the toner is primarily a polyvinyl acetate-based material, methanol can be selected as the removal solution. The liquid toner for electrophotography proposed by the present inventors can also be used as the toner (see the specification of Japanese Patent Application No. 2019-209237). Liquid toner is advantageous compared to dry toner in forming a high-resolution toner image 40. The drying conditions immediately after development are 110°C for 3 minutes.

[0030] 8 shows the process of transferring a toner image onto an arbitrary substrate T. After the toner image 40 is brought into close contact with the arbitrary substrate T, heat and pressure are applied to transfer the toner image 40 onto the substrate T. In the example of FIG. 8, the toner image 40 and the substrate T were in close contact with each other and passed between nip rolls having a surface temperature of 110° C., thereby transferring the toner image 40 onto the substrate T. The substrate T may be made of any material as long as it has the surface properties (surface roughness, wetting index, etc.) and heat resistance required for adhesion of the toner image 40. Examples include molded products and laminates made of various materials such as plastics, glass, glass epoxy resin, ceramics, and metal. To improve adhesion to the toner image 40, the substrate T may be subjected to surface treatment (plasma treatment, corona treatment, adhesive layer coating, etc.). FIG. 8 shows an example in which the substrate T is a glass plate having a thickness of 0.5 mm.

[0031] 9 shows the metal layer coating step: The surface of the substrate T onto which the toner image 40 has been transferred is coated with a metal layer 60 by a physical manufacturing method. Physical fabrication methods, or PVD (Physical Vapor Deposition), are film formation methods that utilize physical phenomena in a vacuum and are classified into sputtering methods (DC sputtering, DC magnetron sputtering, RF sputtering, RF magnetron sputtering, etc.), vacuum evaporation methods (resistance heating, electron beam heating, etc.), and ion plating methods (activated reactive evaporation, high-density plasma-assisted evaporation, etc.). When forming a metal layer, DC magnetron sputtering or vacuum evaporation is preferred from the viewpoint of film formation speed. Before forming the metal layer, the surface to be coated with the metal layer may be subjected to surface modification by plasma treatment or the like.

[0032] FIG. 9 shows an example in which DC magnetron sputtering was used as a physical manufacturing method. A copper target was set on the cathode of a DC magnetron sputtering device, and the substrate T was attached to a substrate holder. -4 After evacuating the chamber to 0.2 Pa, argon gas was introduced and the pressure was adjusted to 0.2 Pa. After sputtering was performed by applying a voltage to the cathode, the film formation chamber was broken and the substrate T was removed. The toner image 40 on the substrate T and the surface of the substrate T without the toner image 40 were both coated with a copper layer 60.

[0033] 10 shows the toner image removal step. The toner image 40 on the substrate T is removed together with the copper layer 60 on the toner image 40. As a result, the copper layer 60 that directly covered the substrate T remains, forming a copper image. In the example of FIG. 10, the toner image 40 was removed by immersing the substrate in methanol for 1 minute while applying ultrasonic vibrations, and then the substrate was washed with water for 1 minute. The copper image formed on the substrate T had a thickness of 100 nm, a line width of 50 μm, and a line spacing of 50 to 150 μm.

[0034] If necessary, the metal image formed by the above method may be subjected to an electroless plating process, or a combination of electroless plating and electroplating, to laminate the same or a different metal on the metal image formed by the above method. By performing such an electroless plating process, or a combination of electroless plating and electroplating, it is possible to improve the strength, conductivity, and other properties of the entire metal image, including the metal laminate portion. INDUSTRIAL APPLICABILITY

[0035] The present invention can be used in various industrial fields such as commercial printing, card business, and cosmetic containers, in addition to the electronics field. [Explanation of symbols]

[0036] S: Electrostatic printing laminate 11: Conductive layer 12: Insulating layer 13: Release layer 14: Backing layer 15: Adhesive layer 16: Exposed conductive layer 20:Original version 21: Electrode 22: Plate layer 30: Toner image 40: Toner image T: Substrate T 50: Metal layer 60: Metal layer

Claims

1. A laminate for electrostatic printing, characterized in that it has an insulating layer on one side and a backing layer on the other side sandwiching a conductive layer, and has an exposed portion of the conductive layer that can be electrically connected to either the insulating layer side or the backing layer side at one or both ends in the transverse direction, and that an electrostatic pattern can be formed on the insulating layer.

2. A laminate for electrostatic printing, characterized in that an insulating layer and a release layer are laminated in this order on one side of the conductive layer, and a backing layer is laminated on the other side, and that at one or both ends in the transverse direction, an exposed portion of the conductive layer is electrically connectable to either the insulating layer side or the backing layer side, and that an electrostatic pattern can be formed on the release layer.

3. 3. The laminate for electrostatic printing according to claim 1, wherein the exposed portion of the conductive layer has a width of 1 to 100 mm.

4. 4. The electrostatic printing laminate of claim 1, claim 2 or claim 3, characterized in that the insulating layer and / or the backing layer is made of a molded material such as polyimide, polycarbonate, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), cycloolefin polymer, cycloolefin copolymer, fluorine-based resin or the like.

Images