Plasma generator and plasma generation method

Abstract

To provide a novel plasma generating device and method that are capable of generating low-temperature plasma under an atmospheric pressure with reduced power consumption, and capable of, for example, performing surface modification on a workpiece such as a polymer film.SOLUTION: A plasma generating device 1 for generating plasma includes a roll-type brush 10, a counter electrode 20 facing the roll-type brush 10, an AC power supply unit 30 that is electrically connected to the roll-type brush 10 and the counter electrode 20 and applies an AC voltage, and a moving mechanism 40 for moving the roll-type brush 10 and the counter electrode 20 relatively to each other. The AC power supply unit 30 sets the counter electrode 20 at a ground potential and applies an AC voltage between the roll-type brush 10 and the counter electrode 20. The moving mechanism 40 moves the roll-type brush 10 and the counter electrode 20 relatively to slide the roll-type brush 10 on the surface of the counter electrode 20 or a dielectric material, thereby generating plasma between the roll-type brush 10 and the surface of the counter electrode 20 or the dielectric material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plasma generating apparatus and a plasma generating method capable of, for example, surface modification of an object to be processed such as a polymer film.

Background Art

[0002] As a method capable of performing surface modification on an object to be processed such as a polymer film, for example, plasma treatment, corona discharge treatment, and ultraviolet irradiation treatment can be mentioned.

[0003] In plasma treatment, surface modification is performed by bringing the generated plasma into contact with the object to be processed. Plasma treatment is classified into vacuum plasma treatment and atmospheric pressure plasma treatment. The former generates plasma in a sealed vacuum chamber, and the latter generates plasma by applying an alternating voltage of high frequency and high voltage in an atmosphere such as nitrogen gas or rare gas. However, plasma treatment has problems in that the plasma generating apparatus is expensive, the power consumption is large, and it is not suitable for in-line processing (for example, Patent Document 1).

[0004] In corona discharge treatment, gas in the atmosphere is ionized to generate discharge, thereby performing surface modification of the object to be processed. However, since it is necessary to apply a high-voltage alternating voltage of 10 kV to 20 kV, corona discharge treatment also has problems in that the power consumption is large and a large amount of ozone is generated. In addition, there is a problem in that dielectric breakdown occurs in the object to be processed and the in-plane processing is non-uniform, resulting in processing marks on the surface of the object to be processed (for example, Patent Document 2).

[0005] In ultraviolet irradiation treatment, for example, excimer light (wavelength: 308 nm) is generated on the surface of the object to be processed to perform surface modification. However, ultraviolet irradiation treatment has a problem in that a large amount of ozone is generated (for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-111611 [Patent Document 2] Japanese Patent Application Publication No. 6-136158 [Patent Document 3] Japanese Patent Publication No. 2021-197269 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a novel plasma generating apparatus and plasma generating method that can generate low-temperature plasma with low power consumption under atmospheric pressure, and that can, for example, perform surface modification on materials to be treated, such as polymer films. [Means for solving the problem]

[0008] The plasma generator according to the present invention is a plasma generator that generates low-temperature plasma under atmospheric pressure in order to solve the above problems, and comprises a sliding electrode member, a counter electrode that directly or indirectly faces the sliding electrode member via a dielectric, an AC power supply unit that is electrically connected to the sliding electrode member and the counter electrode and applies an AC voltage, and a moving mechanism that moves the sliding electrode member and the counter electrode relative to each other, wherein the AC power supply unit sets the counter electrode to ground potential and applies an AC voltage between the sliding electrode member and the counter electrode, and the moving mechanism moves the sliding electrode member and the counter electrode relative to each other, thereby causing the sliding electrode member to slide on the surface of the counter electrode or the dielectric, thereby generating plasma between the sliding electrode member and the surface of the counter electrode or the dielectric.

[0009] In the above configuration, the sliding electrode member may be a roll-type brush having a plurality of brush bristles on its surface, and the rotation of the roll-type brush causes the brush bristles to slide on the surface of the counter electrode or the dielectric, thereby generating plasma between the plurality of brush bristles and between the plurality of brush bristles and the counter electrode or the dielectric.

[0010] Furthermore, in the above configuration, it is preferable that the dielectric is a polymer film with a thickness of 300 μm or less.

[0011] Furthermore, in the above configuration, it is preferable that the polymer film is a tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin film, a fluorinated ethylene propylene film, a polytetrafluoroethylene film, a polyethylene terephthalate film, a biaxially oriented polypropylene film, a biaxially oriented polyamide film, a polypropylene film, or a polyethylene film.

[0012] The plasma generation method according to the present invention is a plasma generation method using a plasma generation apparatus having the above configuration, in order to solve the above problems, characterized in that the AC power supply unit applies an AC voltage between the sliding electrode member and the counter electrode with the counter electrode at ground potential, the moving mechanism moves the sliding electrode member and the counter electrode relative to each other, causing the sliding electrode member to slide on the surface of the counter electrode or the dielectric, thereby generating plasma between the sliding electrode member and the surface of the counter electrode or the dielectric. [Effects of the Invention]

[0013] According to the present invention, the AC power supply unit is electrically connected to the sliding electrode member and the counter electrode, and applies an AC voltage. The moving mechanism moves the sliding electrode member and the counter electrode relative to each other, thereby causing the sliding electrode member to slide against the counter electrode or dielectric. Therefore, with the above configuration, by applying an AC voltage to the sliding electrode member and the counter electrode and sliding the sliding electrode member against the counter electrode or dielectric, a spark discharge can be generated between the sliding electrode member and the counter electrode or dielectric. Furthermore, based on this spark discharge, an atmospheric pressure low-temperature plasma can be generated between the sliding electrode member and the counter electrode or dielectric. In other words, with the above configuration, a novel plasma generator and plasma generation method can be provided that can generate a low-temperature plasma with low power consumption under atmospheric pressure using a simple device configuration. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing a plasma generator according to Embodiment 1 of the present invention. [Figure 2] This is a schematic cross-sectional view showing a roll-type brush in a plasma generator according to Embodiment 1 of the present invention. [Figure 3] This is a schematic diagram showing a plasma generator according to Embodiment 2 of the present invention. [Figure 4] This is a schematic perspective view of a flat brush in a plasma generator according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0015] (Embodiment 1) A plasma generator according to Embodiment 1 of the present invention will be described below. The plasma generation device of Embodiment 1 can generate low-temperature (non-thermal equilibrium) microplasma under atmospheric pressure. Therefore, the plasma generation device of this embodiment can be used as a surface modification device capable of performing surface modification on an object to be processed made of a dielectric such as a polymer film. Hereinafter, an example in which the plasma generation device of this embodiment is applied to a surface modification device will be described.

[0016] In this specification, "under atmospheric pressure" means an environment within a range of 0.7 atm or more and 1.3 atm or less centered on the standard atmospheric pressure (1 atm, 1013 hPa). Also, in this specification, "low temperature" means within the range of 0°C to 400°C, preferably 0°C to 250°C, more preferably 0°C to 150°C. Further, in this specification, "dielectric" means a material or substance having the property (dielectric property) of being electrically polarized (or dielectric polarization or electric polarization) positive and negative by an electric field.

[0017] As shown in FIG. 1, the plasma generation device 1 of this embodiment is a surface modification device that surface-modifies the surface of an object to be processed made of a dielectric in an atmosphere containing at least oxygen, and includes a roll-type brush 10 that is a cylindrical sliding electrode member capable of rotating while being in contact with the surface of the object to be processed, a counter electrode 20 facing the roll-type brush 10 through the object to be processed, an AC power supply unit � that is electrically connected to the roll-type brush 10 and the counter electrode 20 and applies an AC voltage, and a moving mechanism 40 that relatively moves the roll-type brush 10 and the counter electrode 20. FIG. 1 is an explanatory diagram schematically showing the surface modification device according to this embodiment.

[0018] Examples of the object to be processed made of a dielectric include a polymer film 2 as shown in FIG. 1. Further, the polymer film 2 is not particularly limited, and examples thereof include fluororesin films such as tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin films, fluorinated ethylene propylene films, and polytetrafluoroethylene films; polyethylene terephthalate films; biaxially stretched polypropylene films; biaxially stretched polyamide films; polypropylene films; and polyethylene films.

[0019] The thickness of the polymer film 2 is preferably within the range of 300 μm or less, more preferably within the range of 50 μm or less, and even more preferably within the range of 25 μm or less. By setting the thickness to 300 μm or less, the surface of the polymer film 2 can be favorably surface-modified (hydrophilicized).

[0020] As shown in FIG. 2, the roll-type brush 10 includes a shaft 11, a conductive coating layer 12, brush bristles 13, a power supply member 14, and a conductive member 15. FIG. 2 is a schematic cross-sectional view showing the roll-type brush 10 in the plasma generation device 1.

[0021] The shaft 11 is, for example, a columnar member made of a polymer resin, metal, or the like. The shaft 11 may be a solid body or a hollow body. From the viewpoint of weight reduction, the shaft 11 is preferably a hollow body. Further, the shaft 11 can be rotated around its axis by the moving mechanism 40.

[0022] The polymer resin is not particularly limited and examples include polypropylene, acrylonitrile-butadiene-styrene resin, polystyrene, polyethylene, melamine resin, phenolic resin, silicone resin, polyacetal, polyamide resin, polybutylene terephthalate, polyphenylene ether, polyphenylene sulfide, polyethersulfone, polycarbonate, polyimide, polyamideimide, polyetherimide, polysulfone, polyetheretherketone, polyethylene terephthalate, polyarylate, liquid crystal polymer, and polytetrafluoroethylene. The exemplified polymer resins can be used individually or in combination of two or more.

[0023] The conductive coating layer 12 is provided on the outer circumferential surface of the shaft 11. The conductive coating layer 12 consists of, for example, a conductive adhesive layer. When the conductive coating layer 12 consists of a conductive adhesive layer, its constituent materials are not particularly limited. For example, adhesives mainly composed of acrylic resin, polyvinyl acetate, polyurethane, synthetic rubber, and natural rubber contain a conductive material. Furthermore, the conductive material is not particularly limited, and examples include conductive powders of metals and carbon. Furthermore, the conductive powder of metal is not particularly limited, and examples include powders of noble metals such as Ag, Pt, and Au; powders of metals or alloys thereof such as Cu, Ni, Fe, Cr, Co, Al, Sb, and Mo, or oxides. Furthermore, the conductive powder of carbon is not particularly limited, and examples include carbon black, carbon fibers, and graphite particles. These conductive materials may be used individually or in combination of two or more. The amount of conductive material added to the conductive coating layer 12 is not particularly limited and can be set as appropriate.

[0024] The thickness of the conductive coating layer 12 is not particularly limited, and is usually in the range of 50 μm to 600 μm, preferably 100 μm to 500 μm, and more preferably 150 μm to 300 μm. By making the thickness of the conductive coating layer 12 50 μm or more, the shape stability of the brush bristles 13 can be improved. Furthermore, by making the thickness of the conductive coating layer 12 600 μm or less, it is possible to prevent so-called adhesive seepage when the brush bristles 13 are implanted. As a result, it is possible to prevent the occurrence of areas where the conductive coating layer 12 is not formed after the applied adhesive has dried.

[0025] The brush bristles 13 are implanted and held in an upright position in the conductive coating layer 12. It is undesirable for the brush bristles 13 to be implanted in the conductive coating layer 12 in a so-called bent state. If the bristles are bent, it may be difficult to make uniform contact between the brush bristles 13 and the workpiece. Examples of methods for implanting the brush bristles 13 include electrostatic implantation.

[0026] The brush bristles 13 are preferably conductive. This allows power to be supplied to the brush bristles 13. In this embodiment, a cylindrical roll-type brush 10 is used as a sliding electrode member, so that the brush bristles 13 can be made to come into uniform contact with the workpiece.

[0027] Examples of brush bristles 13 include polymer fibers with a metal plating layer on at least a portion of their surface, or polymer fibers with conductive particles attached. Alternatively, a polymer resin layer in which the conductive particles are dispersed may be provided on the surface of the polymer fibers.

[0028] The polymer fibers are not particularly limited and include, for example, polyamide fibers such as nylon® fibers and aramid fibers; polyester fibers such as polyethylene terephthalate fibers and polyarylate fibers; acrylic fibers such as polyacrylonitrile fibers; polyolefin fibers such as polyethylene fibers and polypropylene fibers; and fluorine fibers such as polytetrafluoroethylene fibers. Other examples include regenerated fibers such as rayon fibers and cupro fibers; and semi-synthetic fibers such as cellulose acetate fibers such as acetate fibers and triacetate fibers. Furthermore, natural fibers such as hemp, cotton, and wool are also included. Of the exemplified synthetic fibers, regenerated fibers, semi-synthetic fibers, and natural fibers, one type may be used alone, or two or more types may be used in a blend. However, from the viewpoint of generating spark discharges well, it is preferable to use any of the exemplified polymer fibers alone.

[0029] The metal plating layer is not particularly limited and includes, for example, a copper plating layer, a nickel plating layer, a gold plating layer, and a silver plating layer. The conductive particles are also not particularly limited and include, for example, tin oxide, titanium oxide, molybdenum silicide, tungsten carbide, carbon black, carbon short fibers, and graphite particles. The adhesive for bonding the conductive particles to the surface of the polymer fibers is also not particularly limited and includes, for example, an adhesive mainly composed of acrylic resin, polyvinyl acetate, polyurethane, synthetic rubber, or natural rubber.

[0030] Furthermore, the polymer resin layer is not particularly limited, and examples include one whose main component is the aforementioned adhesive.

[0031] The length of the brush bristles 13 is not particularly limited and can be set appropriately considering the nip width with respect to the polymer film 2. The length of the brush bristles 13 is usually preferably in the range of 1.5 mm to 7 mm from the base portion implanted in the conductive coating layer 12, and more preferably in the range of 4 mm to 6 mm. The thickness (diameter, fiber diameter) of the brush bristles 13 is also not particularly limited and can be set appropriately. For example, the diameter of the brush bristles 13 is preferably in the range of 15 μm to 35 μm.

[0032] The bristle density of the 13 brush bristles is 9000 bristles / cm². 2 ~40000 pieces / cm 2 It is preferable.

[0033] The amount of penetration of the brush bristles 13 into the polymer film 2 is preferably in the range of -2 mm to +2 mm, and more preferably in the range of +0.5 mm to +1.5 mm. By making the penetration amount -2 mm or more, spark discharge can be generated well. On the other hand, by making the penetration amount +2 mm or less, the load applied to the brush bristles 13 by the relative movement between the roll-type brush 10 and the counter electrode 20 can be appropriately adjusted, so that the polymer film 2 is slid with an appropriate force. In this specification, "penetration amount" means the length of penetration into the polymer film 2, assuming that the brush bristles 13 enter the polymer film 2 linearly without bending on the surface when the brush bristles 13 come into contact with the polymer film 2 or the counter electrode 20.

[0034] The power supply member 14 supplies AC power output from the AC power supply unit 30 to the brush bristles 13 via the conductive coating layer 12 and the conductive member 15. The power supply member 14 is provided at one end of the shaft 11 and is electrically connected to the AC power supply unit 30 via a power supply line (not shown). In this invention, the position where the power supply member 14 is provided is not limited to the end of the shaft 11, but can be changed as appropriate.

[0035] The conductive member 15 is made of a conductive material and is provided at one end of the shaft 11 to be electrically connected to the conductive coating layer 12 and the power supply member 14. As a result, the conductive member 15 can conduct AC power from the power supply member 14 to the conductive coating layer 12.

[0036] The counter electrode 20 is, for example, a plate-shaped metal electrode made of metal. The counter electrode 20 is positioned to face the roll-type brush 10. A polymer film 2, which is the material to be processed, is placed on the surface of the counter electrode 20. Preferably, the polymer film 2 is fixed to the surface of the counter electrode 20. Furthermore, the counter electrode 20 is positioned together with the roll-type brush 10 so that the brush bristles 13 are in contact with the surface of the polymer film 2. The counter electrode 20 is also electrically connected to the AC power supply unit 30, enabling the application of AC power output from the AC power supply unit 30. Furthermore, the counter electrode 20 is electrically grounded.

[0037] The AC power supply unit 30 includes, for example, a high-frequency generator and a high-voltage transformer (neither of which are shown in the figure). The high-frequency generator generates AC power in the range of, for example, 0.1 kHz or more and 100 kHz or less, preferably 1 kHz or more and 20 kHz or less. The high-voltage transformer boosts the AC voltage (Vp-p) generated by the high-frequency generator to within the range of 1 kVpp or more and 12 kVpp or less, preferably 1.5 kVpp or more and 6 kVpp or less.

[0038] Furthermore, the AC power supply unit 30 is electrically connected to the power supply member 14 and the counter electrode 20 of the roll-type brush 10. This allows the AC power supply unit 30 to apply an AC voltage to the roll-type brush 10 and the counter electrode 20.

[0039] The moving mechanism 40 rotates the roll-type brush 10 around its axis in the direction indicated by arrow A in Figure 1. The moving mechanism 40 also moves the counter electrode 20 in parallel in the direction indicated by arrow B in Figure 1. This allows the moving mechanism 40 to move the roll-type brush 10 and the counter electrode 20 relative to each other. As a result, the brush bristles 13 that are in contact with the surface of the polymer film 2 can be slid along the surface of the polymer film 2. This allows the brush bristles 13 to slide uniformly within the surface even if the surface area of ​​the polymer film 2 is large, and uniform surface modification can be performed within the surface. Furthermore, by rotating the roll-type brush 10 and moving the counter electrode 20 in parallel, the brush bristles 13 can be slid efficiently along the surface of the polymer film 2 in a short amount of time.

[0040] The plasma generator 1 of this embodiment 1 generates low-temperature microplasma by performing the operations described below, thereby enabling surface modification of the polymer film 2.

[0041] Specifically, the AC power supply unit 30 applies an AC voltage between the roll-type brush 10 and the counter electrode 20, with the counter electrode 20 at ground potential. Furthermore, while the AC voltage is applied, the moving mechanism 40 rotates the roll-type brush 10 around its axis in the direction indicated by arrow A, and simultaneously moves the counter electrode 20 in parallel in the direction indicated by arrow B. This causes the brush bristles 13 of the roll-type brush 10 to slide on the surface of the polymer film 2.

[0042] At this time, millions of electrical contacts exist between each brush bristle 13, causing minute spark discharges due to mutual contact. Spark discharges also occur between the brush bristle 13 and the polymer film 2 due to sliding. Furthermore, these spark discharges generate plasma at low temperatures between the brush bristle 13 and the counter electrode 20. The generated plasma dissociates and / or excites oxygen molecules present in the atmosphere (air) between the brush bristle 13 and the counter electrode 20. This results in the formation of, for example, hydroxyl radicals (OH) and superoxide anion radicals (O). 2-Various reactive oxygen species, including radicals such as ), are generated. Furthermore, when these reactive oxygen species come into contact with the surface of polymer film 2, they bind to the polymer compounds on the surface of polymer film 2, introducing hydrophilic functional groups such as hydroxyl groups and carbonyl groups to the surface of polymer film 2. As a result, the surface of polymer film 2 becomes hydrophilic.

[0043] As described above, in the plasma generator 1 and plasma generation method using the same of this embodiment, atmospheric pressure low-temperature microplasma can be generated by generating spark discharge simply by sliding a roll-type brush 10 on a polymer film 2 under atmospheric pressure and in an atmosphere containing at least oxygen. In other words, the plasma generator 1 of this embodiment has a simpler configuration compared to, for example, conventional plasma generators, and therefore the equipment cost can be reduced. Furthermore, the plasma generator 1 of this embodiment can also be used effectively for in-line surface modification treatments.

[0044] Furthermore, since the plasma generator and plasma generation method of this embodiment can generate microplasma with a relatively low AC voltage of 660V to 6kV, electricity consumption can be reduced compared to, for example, conventional plasma generators and corona generators. In addition, dielectric breakdown of the polymer film 2 can be prevented or reduced when surface modification of the polymer film 2 is performed. Dielectric breakdown refers to irreversible dielectric breakdown that occurs when a voltage higher than the withstand voltage (dielectric strength) of the polymer film 2 is applied and the film is unable to withstand it and breaks down.

[0045] Furthermore, the plasma generator and plasma generation method of this embodiment make it possible to uniformly modify the surface of the polymer film 2, thereby preventing or reducing the occurrence of processing irregularities caused by uneven processing.

[0046] Furthermore, the plasma generator and plasma generation method of this embodiment can suppress or reduce ozone generation compared to conventional corona discharge treatment and ultraviolet irradiation treatment.

[0047] (Embodiment 2) Next, a plasma generator according to Embodiment 2 of the present invention will be described below. As shown in Figure 3, the plasma generator 3 of this embodiment 2 differs from the plasma generator 1 of embodiment 1 mainly in that it uses a flat brush 50 as the sliding electrode member and a roll-type counter electrode 60 as the counter electrode. Figure 3 is a schematic diagram showing the general configuration of the plasma generator 3 according to embodiment 2. In the following, components having the same function as those in the plasma generator 1 of embodiment 1 are denoted by the same reference numerals and their descriptions are omitted.

[0048] As shown in Figure 4, the flat brush 50 comprises at least a flat plate 51 as a base, a conductive coating layer 12 provided on the flat plate 51, and brush bristles 13 electrostatically implanted on the conductive coating layer 12. Figure 4 is a schematic perspective view of the flat brush 50. The flat plate 51 is not particularly limited and can be made of, for example, a resin plate or a metal plate. The flat brush 50 is positioned together with the roll-type counter electrode 60 so that the brush bristles 13 contact the surface of the polymer film 2. The flat brush 50 has the same configuration as the roll-type brush 10 except that it uses a flat plate 51 instead of a shaft 11 as a base.

[0049] Furthermore, a power supply member (not shown) is provided at one end of the flat brush 50, which enables the application of AC power output from the AC power supply unit 30.

[0050] The amount of penetration of the flat brush 50 into the polymer film 2 is the same as the amount of penetration of the roll brush 10 into the polymer film 2 (see Embodiment 1). Therefore, a detailed explanation is omitted.

[0051] The roll-type counter electrode 60 is a cylindrical metal electrode made of metal. From the viewpoint of reducing the weight of the plasma generator 3, the roll-type counter electrode 60 is preferably hollow. The roll-type counter electrode 60 is also provided so as to face the flat brush 50. As shown in Figure 3, a polymer film 2, which is the material to be processed, is wound around the surface of the roll-type counter electrode 60, and it can be rotated around its axis by the moving mechanism 40. In addition, a power supply member (not shown) is provided at one end of the roll-type counter electrode 60, thereby enabling the application of AC power output from the AC power supply unit 30. Furthermore, the roll-type counter electrode 60 is electrically grounded.

[0052] The plasma generator 3 of this embodiment 2 operates as described below to generate microplasma and modify the surface of the polymer film 2.

[0053] Specifically, the AC power supply unit 30 applies an AC voltage between the flat brush 50 and the roll-type counter electrode 60, with the roll-type counter electrode 60 at ground potential. Furthermore, while the AC voltage is applied, the moving mechanism 40 rotates the roll-type counter electrode 60 around its axis in the direction indicated by arrow C, and simultaneously transports the polymer film 2 in the direction indicated by arrow D. This causes the brush bristles 13 of the flat brush 50 to slide on the surface of the polymer film 2. As a result, similar to the first embodiment, spark discharge occurs between the brush bristles 13 and between the brush bristles 13 and the polymer film 2, and atmospheric pressure low-temperature plasma can be generated due to this spark discharge. The mechanism by which hydrophilic functional groups are introduced to the surface of the polymer film 2 and hydrophilized by the generation of atmospheric pressure low-temperature plasma is the same as in the first embodiment.

[0054] (Other matters) The above description has described preferred embodiments of the present invention. However, the present invention is not limited to these embodiments and can be implemented in various other forms.

[0055] For example, in Embodiments 1 and 2, a brush in which brush bristles 13 are electrostatically implanted in a conductive coating layer 12 was described as an example of a sliding electrode member. However, the sliding electrode member of the present invention is not limited to this embodiment, and may be a brush constructed by, for example, wrapping a base fabric in which brush bristles 13 are woven by pile weaving around the outer surface of the shaft 11 in Embodiment 1, or by providing it on the surface of the flat plate 51 in Embodiment 2.

[0056] In this embodiment, a conductive backcoat layer is provided on the back side of the base fabric, that is, on the side opposite to the surface where the brush bristles 13 are raised. This conductive coating layer firmly holds the warp and weft threads constituting the base fabric, as well as the roots of the brush bristles 13. Specifically, the conductive coating layer is composed of an adhesive layer containing a conductive filler, such as a conductive ceramic filler. Furthermore, the warp and weft threads constituting the base fabric are not particularly limited and include, for example, synthetic fibers such as polyamide fibers, polyester fibers, acrylic fibers, polyolefin fibers, and fluorine fibers; natural fibers such as hemp, cotton, and wool; regenerated fibers such as rayon fibers and cupro fibers; and semi-synthetic fibers such as cellulose acetate fibers.

[0057] Furthermore, Embodiment 1 described an example where the power supply member 14 and the conductive member 15 are separate components. However, the present invention is not limited to this embodiment, and the power supply member 14 and the conductive member 15 may be integrally configured. [Examples]

[0058] (Example 1) In this embodiment, a hydrophilization treatment was performed on a 30 μm thick tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (PFA) film using the plasma generator according to Embodiment 1. The treatment conditions were as follows. AC voltage: 3kVpp Frequency: 3kHz Application time: 5 seconds Roll brush rotation speed: 1.5s -1 Brush bristle type: Nylon conductive thread Brush bristle density: 10,000 bristles / cm 2 Brush bristle penetration depth: 1mm PFA film transport speed: 1 mm / s

[0059] (Example 2) In this embodiment, a fluorinated ethylene propylene (FEP) film was used as the material to be treated instead of a PFA film. Otherwise, the hydrophilization treatment was carried out in the same manner as in Example 1.

[0060] (Example 3) In this embodiment, a 20 μm thick polytetrafluoroethylene (PTFE) film was used as the material to be treated, instead of the PFA film. Otherwise, the hydrophilization treatment was carried out in the same manner as in Example 1.

[0061] (Example 4) In this embodiment, a 50 μm thick polyethylene terephthalate (PET) film was used as the material to be treated, instead of the PFA film. Otherwise, the hydrophilization treatment was performed in the same manner as in Example 1.

[0062] (Wettability test) For each polymer film obtained in the examples after hydrophilization treatment, the surface tension was measured by a wettability test in accordance with JIS K 6768 (Plastics - Films and Sheets - Wetting Tension Test Method) under conditions of 25°C and 60% relative humidity. The surface tension of each polymer film before hydrophilization treatment was also measured using the same method. Various wettability test mixtures (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were used as reagents for measurement. The results are shown in Table 1.

[0063] [Table 1]

[0064] (result) As can be seen from Table 1, when surface modification treatment was performed using the plasma generator of the present invention, the surface tension value increased in all of the polymer films of Examples 1 to 4 compared to before treatment. This confirmed that each polymer film was successfully hydrophilized. [Explanation of symbols]

[0065] 1, 3… Plasma generator 2… Polymer film 10… Roll-type brush 11…Shaft 12…Conductive coating layer 13…Brush bristles 14…Power supply components 15...Conductive material 20… Counter electrode 30…AC power supply section 40...Movement mechanism 50…Flat brush 51...Flat plate 60... Roll-type counter electrode

Claims

1. A plasma generator that generates low-temperature plasma under atmospheric pressure, Sliding electrode member and A counter electrode facing the sliding electrode member, An AC power supply unit that is electrically connected to the sliding electrode member and the counter electrode and applies an AC voltage, A moving mechanism for relatively moving the sliding electrode member and the opposing electrode, Equipped with, The AC power supply unit sets the counter electrode to ground potential and applies an AC voltage between the sliding electrode member and the counter electrode. The dielectric material to be processed is placed on the counter electrode such that the sliding electrode member and the counter electrode face each other through the dielectric material. The aforementioned moving mechanism moves the sliding electrode member and the opposing electrode relative to each other, thereby causing the sliding electrode member to slide on the surface of the dielectric. This generates plasma between the sliding electrode member and the surface of the dielectric, thereby performing surface modification on the surface of the dielectric. Plasma generator.

2. The sliding electrode member is a roll-type brush having multiple brush bristles on its surface, The rotation of the roll-type brush causes the brush bristles to slide against the surface of the opposing electrode or the dielectric, The plasma generating device according to claim 1, which generates plasma between the plurality of brush bristles and between the plurality of brush bristles and the counter electrode or the dielectric.

3. The plasma generator according to claim 1, wherein the dielectric is a polymer film with a thickness of 300 μm or less.

4. The plasma generator according to claim 3, wherein the polymer film is a tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin film, a fluorinated ethylene propylene film, a polytetrafluoroethylene film, a polyethylene terephthalate film, a biaxially oriented polypropylene film, a biaxially oriented polyamide film, a polypropylene film, or a polyethylene film.

5. A plasma generation method using a plasma generator according to any one of claims 1 to 4, The dielectric material to be processed is placed on the counter electrode such that the sliding electrode member and the counter electrode face each other through the dielectric material. The AC power supply unit applies an AC voltage between the sliding electrode member and the counter electrode, with the counter electrode at ground potential. The aforementioned moving mechanism moves the sliding electrode member and the opposing electrode relative to each other, causing the sliding electrode member to slide on the surface of the dielectric. This provides a plasma generation method in which plasma is generated between the sliding electrode member and the surface of the dielectric, thereby performing surface modification on the surface of the dielectric.

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