JP2023027634A - Electrostatic printing method - Google Patents

Abstract

To provide a newly developed electrostatic printing method that is suitable for manufacturing of a wide variety of products in small quantities, which can easily deal with individual requests for addition, correction and the like of an electrostatic pattern.SOLUTION: A mask sheet, which is formed of a molded body only made of a conductive material or of a laminate made of both of an insulating material and a conductive material and is provided with a predetermined ion-permeable opening part, is closely attached to a surface having a pattern formed thereon of an image receiving sheet formed of an electrical insulation material. Further, a back electrode is arranged on the opposite surface of the surface having a pattern formed of the image receiving sheet and ion irradiation is performed through the mask sheet, and then the mask sheet is peeled off from the image receiving sheet, so as to form an electrostatic pattern corresponding to the ion-permeable opening part is formed on the surface having a pattern formed of the image receiving sheet.SELECTED DRAWING: Figure 1(2)

Description

The present invention comprises an image-receiving sheet made of an electrically insulating material on which a pattern is formed, which is formed of a molded body made of only a conductive material or a laminate of an insulating material and a conductive material, and has predetermined ion-permeable openings. The present invention relates to a method of electrostatic printing using a mask sheet, the principle of which is related to discharge technology, and the use of electrostatic printing is related to electrostatic printer technology represented by electrophotography.

Chester Carlson of the United States invented the world's first practical technology for creating images using static electricity. The technology related to this invention was commonly called the Carlson method or the xerography method, but it has been academically studied as an image forming technology, and is called electrophotography as an academic name, and is named electrophotography in Japan. Copiers and printers made using this technology have become indispensable for office work.

As the name suggests, this technology forms an optical image as an electrostatic latent image using static electricity and a photoreceptor (optical semiconductor), and develops it with charged fine particles called toner. It was developed as a perfect technology for a copier that instantly prints and outputs an image that changes from page to page. It can be said that the development technology and toner, which is the developer, have evolved the most. Powder toner has been made finer to about 6 μm, and uniform particle size and uniform charging have been realized to improve resolving power and transfer stability. In addition, micronized liquid toner has a submicron size, and the stability of the developer has been secured, and the resolution has even surpassed that of printing ink. In addition to color toners, functional toners and development methods have been developed one after another, regardless of whether they are powders or liquids, such as toners containing metals, methods of developing with metals themselves, and toners that can be plated as in Patent Document 2. It's been done.

However, there is a limit to the electrophotography method to fully exhibit the features of these functional toners. It is because of the basic element of creating an electrostatic pattern on the photoreceptor. That is, the electrostatic pattern on the photoreceptor must be developed and the developed toner transferred to the target material. Of course, it is precisely this method that enables high-definition, high-speed printing without a plate. Furthermore, the current photoreceptor has analog characteristics, and it is difficult to simultaneously and accurately print dots and lines of 10 μm and dots and lines of 100 μm or more at high speed. From the point of view of imparting transfer performance, functional toners are inevitably half-finished.

JP-A-8-19272 JP 2007-134422 A

Jonno, Tanaka, Inoue, Tajima: Journal of Electrophotographic Society, Vol. 7, No. 3, p2.

Various attempts have been made in the past to directly develop electrostatic patterns. As one of the commercialized systems, as shown in Non-Patent Document 1, there is an electrostatic transfer system in which an electrostatic pattern itself is transferred from a photoreceptor and directly developed. However, due to the fact that the transfer paper is special and the principle that an electrostatic pattern is created by the peeling discharge action, the resolution is lower than that of the pattern on the photoreceptor. Devices that directly draw electrostatic patterns, such as a multi-stylus and a method that deflects the ion beam, have been commercialized, but due to limitations in electrode processing accuracy and low resolution due to the spread of discharge ions, they have been replaced by the inkjet method. there is
In addition, regarding an electrostatic pattern forming method for an electrostatic actuator, Patent Document 1 proposes obtaining fidelity of the electrostatic pattern to the electrode by providing a partition around the electrode to limit the discharge range. However, the technique of Patent Document 1 cannot create an image pattern like printing or electrophotography.
Combining high-definition patterns using static electricity with ever-evolving toners opens up possibilities for printing with unprecedented effects and performance. is desired.

Therefore, the present inventors proposed a practical high-definition electrostatic printing method for creating images using static electricity that is comparable to, and even surpasses, conventional printing without using a photoreceptor (patent application 2018- 188998).
According to one aspect of the invention, the plate layer is composed of a first electrode having uniform conductivity over the entire surface and a plate layer made of a material having an appropriate uniform thickness and being in close contact with the first electrode. An image-receiving sheet integrated with a conductive layer having a second electrode on the back surface is brought into close contact with an original having a letterpress, intaglio, or gravure pattern formed on it, and the first electrode of the original and the first electrode of the image-receiving sheet are brought into contact with each other. An electrostatic pattern corresponding to the relief, intaglio, or gravure pattern is formed on the image-receiving sheet by applying an appropriate voltage sufficient to discharge the gaps of the relief, intaglio, or gravure pattern between the two electrodes. A method of high definition electrostatic printing is provided, characterized by forming a

The electrostatic pattern on the receiving sheet becomes a visible pattern upon development with charged particles. When the charged particles are particles that can be plated, a high-definition electrode circuit pattern is formed on the image-receiving sheet by performing a plating treatment with the charged particles after development.
However, the high-definition electrostatic printing method has the following problems. The original plate used in the high-definition electrostatic printing method is composed of a first electrode having uniform conductivity over the entire surface and a plate layer having an appropriate uniform thickness that is in close contact with the first electrode. Alternatively, an intaglio or gravure pattern is formed. Since it takes time and money to make the original plate, it is suitable for mass production of a small variety of products, but not suitable for small-lot production of a wide variety of products. Furthermore, it was not easy to respond to individual requests such as addition and correction of static electricity patterns.
The present invention proposes an electrostatic printing method that solves the above problems.

According to the first aspect of the present invention, the pattern-formed surface of the image receiving sheet made of an electrically insulating material is formed of a molded body made of only a conductive material or a laminate of an insulating material and a conductive material, and is provided with predetermined ions. A mask sheet having transparent openings is brought into close contact with the image receiving sheet, a back electrode is arranged on the opposite side of the image receiving sheet from the pattern forming surface, ion irradiation is performed through the mask sheet, and then the mask sheet is peeled off from the image receiving sheet. Thus, an electrostatic printing method is provided, characterized by forming an electrostatic pattern corresponding to the ion-permeable openings on the pattern-formed surface of the image-receiving sheet.
Further, according to the second aspect of the present invention, a molded body of only a conductive material or an insulating material and a conductive A mask sheet B made of a laminate of materials and provided with a predetermined ion-permeable opening B is brought into close contact, and a back electrode is arranged on the opposite side of the pattern-forming surface of the image-receiving sheet. After the ion irradiation, by peeling off the mask sheet B from the image receiving sheet, the ion permeable openings are formed on the pattern forming surface of the image receiving sheet, adjacent to the electrostatic pattern A or partly overlapping the electrostatic pattern A. An electrostatic printing method characterized by forming an electrostatic pattern B corresponding to B is provided.
The electrostatic pattern on the patterned surface of the receiving sheet becomes a visible pattern upon development with charged particles. When the charged particles are particles that can be plated, an electrode circuit pattern is formed on the pattern-formed surface of the image receiving sheet by performing a plating treatment with the charged particles after development.

In order to facilitate understanding of the above configuration and the process of forming an electrostatic pattern, basic conceptual diagrams of FIGS. 1 and 2 will be used. FIG. 1(1) shows a state in which a back electrode 10 is brought into close contact with the surface opposite to the pattern forming surface of the image receiving sheet 20, and the back electrode 10 is grounded. Before the mask sheet 30 is brought into close contact with the pattern-formed surface of the image-receiving sheet 20, the image-receiving sheet 20 is charged with a charge opposite in polarity to the charge for forming the electrostatic pattern (+300 V in this example). This electrification ensures that the mask sheet 30 is brought into close contact with the image receiving sheet 20 . FIG. 1(2) shows a state in which a mask sheet 30 having ion permeable openings 31 is in close contact with the pattern forming surface of the image receiving sheet 20, and ion irradiation is performed through the mask sheet 30 by the ion irradiation means 40. FIG. ing. After the ion irradiation, portions corresponding to the ion permeable openings 31 of the mask sheet surface and the pattern forming surface of the image receiving sheet 20 are charged (-300 V in this example). FIG. 1(3) shows the state after the mask sheet 30 is grounded and separated from the image receiving sheet 20. FIG. An electrostatic pattern 21 is formed on the pattern forming surface of the image receiving sheet 20 . The portion shielded by the mask sheet 30 during ion irradiation is charged to +300V.
FIG. 2(1) shows a state in which the back electrode 10 is adhered to the opposite side of the pattern forming surface of the image receiving sheet 20, and the back electrode 10 is grounded. An electrostatic pattern A (−300 V in this example) is formed in advance on the pattern forming surface of the image receiving sheet 20, and the other portion is charged with a charge opposite in polarity to the electrostatic pattern A (+300 V in this example). . FIG. 1(2) shows a state in which a mask sheet 30 having ion permeable openings 33 is in close contact with the pattern forming surface of the image receiving sheet 20, and ion irradiation is performed through the mask sheet 30 by the ion irradiation means 40. FIG. ing. After the ion irradiation, portions corresponding to the ion permeable openings 33 of the mask sheet surface and the pattern forming surface of the image receiving sheet 20 are charged (-300 V in this example). FIG. 1(3) shows the state after the mask sheet 30 is grounded and separated from the image receiving sheet 20. FIG. An electrostatic pattern B is formed adjacent to the electrostatic pattern A on the pattern forming surface of the image receiving sheet 20 . The portion shielded by the mask sheet 30 during ion irradiation is charged to +300V.

Since the basis of the present invention is an electrostatic pattern formed by ions passing through the ion-permeable openings of the mask sheet without using a peeling discharge, an electrostatic pattern is formed on the pattern forming surface of the image-receiving sheet without spreading of charged ions. be able to. Furthermore, in a state in which the electrostatic pattern A is formed in advance on the pattern-formed surface of the image receiving sheet, by adjusting the position of the ion-permeable opening of the mask sheet, the electrostatic pattern A is adjacent to or aligned with the electrostatic pattern A. A static electricity pattern B can be formed by overlapping. The electrostatic pattern on the pattern-formed surface of the image-receiving sheet becomes a visible pattern by developing with charged particles having a charge opposite to that of the electrostatic pattern. Portions other than the electrostatic pattern are not developed because they have the same polarity as the charged particles. When the charged particles are particles that can be plated, an electrode circuit pattern is formed on the pattern-formed surface of the image receiving sheet by performing a plating treatment with the charged particles after development.

Adhesion of the image receiving sheet and the back electrode, electrification treatment on the pattern forming surface of the image receiving sheet Image-receiving sheet and mask sheet are in close contact, ion irradiation through the mask sheet Mask sheet peeling from image receiving sheet, electrostatic pattern formation Image-receiving sheet on which static electricity pattern A is formed in advance and back electrode adhere to each other Image-receiving sheet and mask sheet are in close contact, ion irradiation through the mask sheet The mask sheet is peeled off from the image receiving sheet, and the electrostatic pattern B is formed adjacent to the electrostatic pattern A.

The basic configuration of the present invention and the basic process of electrostatic pattern formation are as shown in FIGS. 1 and 2. FIG.
Since the image-receiving sheet needs to retain static electricity, at least the pattern-formed surface is made of a material with high electrical insulation. Films and sheets of polyimide, polycarbonate, PET (polyethylene terephthalate), cycloolefin polymer, cycloolefin copolymer, fluororesin, etc. can be used as the image receiving sheet. The thickness of the image-receiving sheet is preferably 5-500 μm. If the thickness is less than 5 μm, handling is difficult. On the other hand, if the thickness exceeds 500 μm, it becomes disadvantageous in terms of flexibility and reduction in thickness.
Also, it is necessary to consider the dielectric constant of the image receiving sheet depending on the purpose of use.

The back electrode may be made of any conductive material as long as it has the role of stabilizing the charge on the pattern-formed surface of the image-receiving sheet. Examples of conductive materials include metals, conductive oxides, conductive polymers, carbon, and graphite.

The back electrode is located on the opposite side of the image receiving sheet from the patterned side. If the back electrode is pressed against the image-receiving sheet, it can fulfill the above-mentioned role. If a conductive layer is formed on the opposite side of the patterned surface of the image receiving sheet by a method of sputtering a metal film, a conductive oxide film or the like, a method of coating a conductive polymer film or the like, a method of laminating a metal foil, or the like. Since the conductive layer can be used as a back electrode, the image-receiving sheet and the back electrode can be integrated. Alternatively, a conductive layer-attached sheet obtained by forming a conductive layer such as a metal film, a conductive oxide film, or a conductive polymer film on a sheet of an electrically insulating material in advance is laminated on the opposite side of the image receiving sheet from the pattern-formed side. Since the conductive layer can be used as the back electrode, the image receiving sheet and the back electrode can be integrated.

When integrating the image-receiving sheet and the back electrode by laminating a sheet with a conductive layer or a metal foil on the opposite side of the image-receiving sheet from the pattern-formed surface, the adhesion of the adhesive layer used for lamination can be adjusted. Also, when the image receiving sheet is used, the image receiving sheet can be peeled off from the back electrode, and the demand for thinning and the demand for a configuration without a conductive layer can be met. In this case, the adhesive force when peeling the image-receiving sheet from the back electrode is preferably 0.01 to 0.3 N/25 mm. If the adhesive strength is less than 0.01 N/25 mm, the image-receiving sheet and the back electrode may float during the electrification process, ion irradiation process, and development process, and the intended electrostatic pattern may not be formed. On the other hand, if the adhesive strength exceeds 0.3 N/25 mm, it is difficult to separate the image-receiving sheet from the back electrode, and the image-receiving sheet may be broken or wrinkled during separation.

During ion irradiation, the mask sheet needs to transmit ions only through the ion-permeable openings and block ions outside the ion-permeable openings. Therefore, except for the ion permeable openings, the entire surface must be electrically conductive. The entire mask sheet need not necessarily be conductive. Therefore, the mask sheet may be made of a molded body of conductive material only or a laminate of conductive material and insulating material, and has predetermined ion-permeable openings.
Sheets made of conductive materials such as metal foils and metal plates, sheets of electrically insulating materials provided with conductive layers such as metal films, etc. are processed by etching, laser processing, or a combination of these. A mask sheet can be made by providing ion permeable openings.

The ion irradiation means is not particularly limited. The ion irradiation method using corona discharge is preferable because it allows treatment in the air, the polarity of irradiation ions can be easily switched, and it can be used in both the charging process and the ion irradiation process.

The electrostatic printing method of the present invention may be practiced alone or in combination with other printing methods. For example, first, an electrostatic pattern A is formed by a high-definition electrostatic printing method (see Japanese Patent Application No. 2018-188998), and then an electrostatic pattern B is formed adjacent to the electrostatic pattern A by the electrostatic printing method of the present invention. can be formed. Alternatively, first, the electrostatic pattern A is formed by the above high-definition electrostatic printing method and then developed to form a visible pattern C, and subsequently the electrostatic pattern B is formed adjacent to the visible pattern C by the electrostatic printing method of the present invention. can be formed. Furthermore, the electrode circuit pattern D can be formed by another printing method, and then the electrostatic pattern B can be formed adjacent to the electrode circuit pattern D by the electrostatic printing method of the present invention. The electrostatic printing method of the present invention is not only suitable for high-mix low-volume production, but also can easily meet individual requests such as addition and correction of electrostatic patterns.

10 back electrode
20 image receiving sheet 21 static electricity pattern 22 static electricity pattern A
23 Static electricity pattern B
30 mask sheet 31 ion permeable opening 33 ion permeable opening 40 ion irradiation means

Claims (7)

A mask sheet consisting of a molded body of only conductive material or a laminated body of insulating material and conductive material and having predetermined ion permeable openings is adhered to the pattern formation surface of the image receiving sheet made of electrically insulating material. Further, a back electrode is arranged on the surface opposite to the pattern-formed surface of the image-receiving sheet, and ion irradiation is performed through the mask sheet. An electrostatic printing method, comprising forming an electrostatic pattern corresponding to the ion-permeable openings. 2. The electrostatic printing method according to claim 1, wherein the image-receiving sheet is charged with an electric charge having a polarity opposite to that for forming the electrostatic pattern before the mask sheet is brought into close contact with the image-receiving sheet. electrostatic printing method. A molded article made of only a conductive material or a laminate of an insulating material and a conductive material having a predetermined ion permeability is applied to the pattern-formed surface of an image-receiving sheet made of an electrically insulating material on which an electrostatic pattern A is formed in advance. A mask sheet B having openings B is brought into close contact, a back electrode is arranged on the surface of the image receiving sheet opposite to the pattern forming surface, ion irradiation is performed through the mask sheet B, and then the mask sheet B is removed from the image receiving sheet. By peeling off, an electrostatic pattern B corresponding to the ion permeable openings B is formed on the pattern forming surface of the image receiving sheet, adjacent to the electrostatic pattern A or partly overlapping the electrostatic pattern A. electrostatic printing method. 4. The electrostatic printing method according to any one of claims 1 to 3, wherein a conductive layer or a sheet with a conductive layer is laminated on the surface opposite to the pattern-formed surface of the image-receiving sheet, and the conductive layer is the back electrode. 5. The electrostatic printing method according to any one of claims 1 to 4, wherein the ion irradiation means is an ion irradiation system using corona discharge. In the electrostatic printing method according to any one of claims 1 to 5, the electrostatic pattern formed on the image receiving sheet is developed with charged particles using a dry development method or a wet development method in electrophotography. An electrostatic printing method characterized by: 7. An electrostatic printing method, wherein the charged particles of claim 6 are platable particles.

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