Active oxygen supply device, treatment device using active oxygen, and treatment method using active oxygen

Abstract

To provide an active oxygen feed device capable of more stably applying a treatment by active oxygen onto a surface of a treatment target.SOLUTION: An active oxygen feed device includes: a housing having an opening; and a plasma actuator and an ozone degradation device therein. The plasma actuator includes a first electrode, a dielectric body and a second electrode laminated in this order, and is configured to, by applying a voltage, blow out an induced flow containing ozone in a first direction being one direction along a surface of the dielectric body from the first electrode. The ozone degradation device is configured to degrade the ozone to generate active oxygen in the induced flow. The plasma actuator and the ozone degradation device are arranged so that the induced flow containing the active oxygen flows out from the opening to an outside of the housing. An edge part at a second direction side being an opposite direction of the first direction of the second electrode includes a projection part extending in the second direction, and overlaps the first electrode only at the projection part, and the projection part has a constant width in the second direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure is directed to an active oxygen supplying device, an active oxygen treatment device, and an active oxygen treatment method. [Background technology]

[0002] Ultraviolet light and ozone are known as means for sterilizing objects, etc. Patent Document 1 addresses the problem that sterilization by ultraviolet light is limited to the part of the object to be sterilized that is irradiated with ultraviolet light, by using a sterilization device having an ozone supply device, an ultraviolet light generating lamp, and an agitator, and by irradiating ozone with ultraviolet light generated from the ultraviolet light generating lamp, the active oxygen generated is agitated, thereby sterilizing the shadow part of the sample as well. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 01-025865 [Non-patent literature]

[0004] [Non-Patent Document 1] Masanobu Wakasa et al., "Effect of magnetic field on photocatalytic reaction using semiconducting titanium oxide thin film", Kyoto Sangyo University Research Institute of Advanced Science and Technology Bulletin, 69, 4, 271-275, (2006) Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors of the present invention have investigated the sterilization performance of the sterilization method disclosed in Patent Document 1 and found that in some cases the sterilization performance was comparable to that of a conventional sterilization method using only ozone. The sterilization ability of active oxygen is said to far exceed that of ozone, so these results were unexpected. At least one aspect of the present disclosure is directed to providing an active oxygen supplying device capable of more stably treating the surface of a workpiece with active oxygen. Another aspect of the present disclosure is directed to providing an active oxygen treatment device capable of more stably treating the surface of a workpiece with active oxygen. Yet another aspect of the present disclosure is directed to providing an active oxygen treatment method capable of more stably treating the surface of a workpiece with active oxygen. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a plasma generating system including: a housing having at least one opening; a plasma actuator disposed inside the housing; and an ozone decomposition device, The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode to the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The active oxygen supplying device is provided in which the convex portion has a constant width in the second direction.

[0007] According to at least one aspect of the present disclosure, there is provided an active oxygen treatment apparatus for treating a surface of a workpiece with active oxygen, the apparatus comprising: The processing device includes a housing having at least one opening, a plasma actuator disposed inside the housing, and an ozone decomposition device; The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode to the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The convex portion has a constant width in the second direction.

[0008] Furthermore, according to at least one aspect of the present disclosure, there is provided a treatment method for treating a surface of a workpiece with active oxygen, comprising: providing an active oxygen treatment device; The treatment device using active oxygen includes a housing having at least one opening, a plasma actuator disposed inside the housing, and an ozone decomposition device; The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode to the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The protrusion has a constant width in the second direction, The treatment method further includes placing the prepared treatment device using active oxygen and the object to be treated in a relative position to which the surface of the object to be treated is exposed when the induced flow containing the active oxygen is caused to flow out from the opening. and and a step of discharging the induced flow containing the active oxygen from the opening to treat the surface of the object with the active oxygen. [Effects of the Invention]

[0009] The present disclosure provides an active oxygen supplying device capable of more stably treating the surface of a workpiece with active oxygen. Another aspect of the present disclosure provides an active oxygen treatment device capable of more stably treating the surface of a workpiece with active oxygen. Yet another aspect of the present disclosure provides an active oxygen treatment method capable of more stably treating the surface of a workpiece with active oxygen. [Brief explanation of the drawings]

[0010] [Figure 1] Schematic cross-sectional view showing the configuration of an active oxygen supply device [Figure 2] Schematic diagram showing the configuration of a plasma actuator [Figure 3] FIG. 1 is an explanatory diagram showing the shape of the edge of the first electrode and the relative position of the first electrode and the second electrode; [Figure 4] Schematic diagram showing the relationship between the first electrode and the second electrode [Figure 5] Schematic diagram illustrating electrode overlap [Figure 6] Schematic diagram illustrating electrode overlap [Figure 7] Schematic diagram illustrating electrode overlap [Figure 8] 10 is an explanatory diagram of a modified example of the shape of the convex portion of the second electrode; [Figure 9] Schematic cross-sectional view showing the configuration of an active oxygen supply device DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0012] In the present disclosure, "treatment" of an object to be treated with active oxygen includes any treatment that can be achieved with active oxygen, such as surface modification (hydrophilization treatment) of the surface of the object to be treated with active oxygen, sterilization, deodorization, and bleaching. Furthermore, the term "microorganisms" as the target of "sterilization" in the present disclosure refers to microorganisms, including fungi, bacteria, unicellular algae, viruses, protozoa, etc., as well as animal or plant cells (including stem cells, dedifferentiated cells, and differentiated cells), tissue cultures, fused cells (including hybridomas) obtained by genetic engineering, dedifferentiated cells, and transformants (microorganisms). Examples of viruses include norovirus, rotavirus, influenza virus, adenovirus, coronavirus, measles virus, rubella virus, hepatitis virus, herpes virus, and HIV virus. Examples of bacteria include Staphylococcus aureus, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Vibrio cholerae, Shigella, Bacillus anthracis, Mycobacterium tuberculosis, Clostridium botulinum, Clostridium tetani, and Streptococcus. Examples of fungi include Trichophyton spp., Aspergillus, and Candida. Therefore, in the present disclosure, "sterilization" also encompasses the inactivation of viruses. Furthermore, the active oxygen in the present disclosure is, for example, superoxide (·O2) generated by decomposition of ozone (O3). - ), including free radicals such as the hydroxyl radical (·OH).

[0013] Hereinafter, specific examples of embodiments for carrying out this disclosure will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in this embodiment should be changed as appropriate depending on the configuration of the member to which the disclosure is applied and various conditions. The scope of the disclosure is not intended to be limited to the following embodiments. In the following description, components having the same functions are denoted by the same reference numerals in the drawings, and their description may be omitted.

[0014] According to the study by the present inventors, the reason why the sterilization ability of the sterilizer according to Patent Document 1 is limited is presumed to be as follows. In Patent Document 1, ozone is excited by irradiating it with ultraviolet light, generating active oxygen with extremely high disinfecting power. Here, the active oxygen is the superoxide anion radical (·O2 -), hydroxyl radical (·OH), and other highly reactive oxygen species, which can instantly oxidize and decompose bacteria and viruses due to their own high reactivity.

[0015] However, because ozone absorbs ultraviolet rays extremely well, it is believed that the generation of active oxygen is limited to the vicinity of the ultraviolet emitting lamp in the sterilization device of Patent Document 1. In other words, it is believed that ultraviolet rays do not sufficiently reach ozone present at a distance from the ultraviolet emitting lamp, and active oxygen is unlikely to be generated at a distance from the ultraviolet emitting lamp. In addition, reactive oxygen species are very unstable, such as ·O2 - The half-life of -6 seconds, and the half-life of OH is 10 -9 It is believed that the active oxygen generated near the ultraviolet lamp is rapidly converted into stable oxygen and water in an extremely short time of only seconds. Therefore, it is believed to be difficult to passively fill the inside of the sterilization device body with active oxygen generated near the ultraviolet lamp. In other words, it is believed that sterilization by the sterilization method of Patent Document 1 is essentially performed by ozone. Therefore, it is believed that the sterilization performance of the sterilization method of Patent Document 1 is equivalent to the sterilization performance of conventional sterilization methods that use only ozone.

[0016] From these considerations, the present inventors have recognized that, in treating a workpiece using active oxygen, it is necessary to more actively place the workpiece or the surface to be treated in an active oxygen atmosphere. Based on this recognition, the present inventors conducted research and found that, with the active oxygen supply device and treatment device using active oxygen according to the present disclosure described below, active oxygen can be reliably delivered to the workpiece while maintaining its treatment capacity. As a result, the present inventors have found that the workpiece can be more actively placed in an active oxygen atmosphere, and that the workpiece can be stably treated.

[0017] 1(a), an active oxygen supplying device (treatment device using active oxygen) 101 according to one embodiment of the present disclosure will be described. The active oxygen supplying device 101 according to one embodiment of the present disclosure includes an ultraviolet light source 102 and a plasma actuator 103 as an ozone decomposition device 102 inside a housing 107 having at least one opening 106. An ultraviolet light source 102, which is an ozone decomposition device, irradiates an induced flow 105 with ultraviolet light to generate active oxygen in the induced flow 105. In Fig. 1(a), reference numeral 104 denotes an object to be treated.

[0018] FIG. 2(a) shows the cross-sectional structure of one embodiment of the plasma actuator 103. This plasma actuator is a so-called dielectric barrier discharge (DBD) plasma actuator (hereinafter, sometimes simply referred to as "DBD-PA"), in which a first electrode 203, which is an exposed electrode with an end face exposed on one surface (hereinafter, also referred to as the "first surface") of a dielectric 201, is provided, and a second electrode 205 is provided on the surface opposite the first surface (hereinafter, also referred to as the "second surface"). In FIG. 2(a), reference numeral 206 denotes a dielectric substrate for burying the second electrode 205 in the thickness direction of the plasma actuator so as to prevent the generation of an induced current from the end face of the second electrode. A voltage can be applied to the first electrode and the second electrode by a power source 207.

[0019] In the plasma actuator 103, the first electrode 203 and the second electrode 205 are disposed with the dielectric 201 sandwiched between them, and are disposed, for example, diagonally opposite each other. By applying a voltage between the first electrode 203 and the second electrode 205 from a power supply 207, a dielectric barrier discharge is generated from the first electrode 203 to the second electrode 205. Then, a jet-like flow of plasma 202 is induced from the edge 204 of the first electrode 203 toward the direction in which the second electrode extends (arrow 208 in FIG. 2(a)) along the exposed portion 201-1 of the first surface of the dielectric 201 (the portion not covered by the first electrode). At the same time, an air suction flow is generated from the space inside the container toward the electrode. Electrons in the surface plasma 202 collide with oxygen molecules in the air, dissociating the oxygen molecules and generating oxygen atoms. The generated oxygen atoms then collide with undissociated oxygen molecules, generating ozone. Therefore, due to the interaction between the jet-like flow caused by the surface plasma 202 and the air suction flow, an induced flow 105 containing a high concentration of ozone is generated from the edge 204 of the first electrode 203 along the surface of the dielectric 201. The plasma actuator 103 and the ozone decomposition device 102 are arranged so that an induced flow 105 containing active oxygen flows out of the housing 107 through an opening 106 and is supplied to a processing surface 104-1 of the workpiece 104.

[0020] That is, the plasma actuator is formed by laminating a first electrode 203, a dielectric 201, and a second electrode 205 in this order, and the first electrode 203 is an exposed electrode provided on a first surface of the dielectric 201. When a voltage is applied between the first electrode 203 and the second electrode 205, the plasma actuator generates a dielectric barrier discharge from the first electrode 203 toward the second electrode 205, and blows out an induced flow from the first electrode 203 in a first direction (the direction of arrow 208 in FIG. 2(a)) that is a direction along the first surface of the dielectric 201. More specifically, a dielectric barrier discharge is generated from one edge 204 of the first electrode 203 toward the second electrode 205, and an induced flow, which is a unidirectional jet, is blown out from the one edge 204 of the first electrode 203 in a first direction (the direction of arrow 208 in Figure 2(a)) along the first surface of the dielectric 201. Also, in one cross section in the thickness direction of the plasma actuator, second electrode 205 exists extending in the blowing direction (first direction) of the induced flow.

[0021] More specifically, for example, the plasma actuator has a dielectric 201, and when a cross section of the plasma actuator in the thickness direction is viewed, a first electrode 203 and a second electrode 205 are arranged diagonally opposite each other in the thickness direction of the plasma actuator, with the dielectric 201 interposed therebetween. The first electrode 203 is provided so as to cover a part of the first surface of the dielectric 201, and the first surface of the dielectric has an exposed portion 201-1 that is not covered by the first electrode 203.

[0022] 2(b) is a perspective view of the plasma actuator from the first surface side of the dielectric. At least a portion of exposed portion 201-1 overlaps with second electrode 205, which is shown by the dashed line. Therefore, the overlap between at least a portion of the exposed portion and the second electrode is the area formed by the dotted line indicating electrode 205 and edge portion 204 in FIG. 2(b). In addition, a convex portion extending in the second direction is provided on the edge of the second electrode on the second direction side, which is the opposite direction to the first direction, and the first electrode and the second electrode overlap only at the convex portion.

[0023] Then, by applying a voltage between the first electrode and the second electrode, an induced flow containing ozone is generated from the edge 204 on the first direction side of the first electrode 203 in the cross section in the thickness direction (Figure 2(a)) along the exposed part of the dielectric overlapping with the second electrode 205.

[0024] The induced flow becomes, for example, a wall jet flow along the exposed portion 201-1, which makes it easy to supply high-concentration ozone to a specific position. The length of the exposed portion 201-1 in the induced flow direction (i.e., the length from the edge 204 on the first direction side of the first electrode to the end of the first surface of the dielectric) is not particularly limited. However, it is preferably 0.1 to 50 mm, more preferably 0.5 to 20 mm, and even more preferably 1.0 to 10 mm. The longer this length is, the longer the plasma 202 extends, and the farther the induced flow reaches. On the other hand, if this length is too long, the distance to the opening 106 becomes long. Therefore, the above range is preferable.

[0025] The ultraviolet light source 102 of the ozone decomposition device 102 irradiates the induced flow 105 with ultraviolet light, decomposing the ozone in the induced flow 105 and generating reactive oxygen species (hereinafter also referred to as "ROS." ROS is an abbreviation for Reactive Oxygen Species) in the induced flow. The plasma actuator 103 and the ultraviolet light source 102 are arranged so that the induced flow 105 containing the reactive oxygen species flows out of the housing 107 through the opening 106 and is supplied to the processing surface 104-1 of the workpiece 104, as shown in FIG. 1(a).

[0026] 1(a), ultraviolet light from the ultraviolet light source 102 is also irradiated onto the surface of the workpiece 104. In this case, even if all of the ozone in the induced flow 105 is not decomposed into active oxygen in the active oxygen supply device, the ozone that reaches the surface of the workpiece 104 is decomposed in situ by the ultraviolet light and becomes active oxygen, so that improvement in treatment efficiency can be expected.

[0027] However, in the active oxygen supply device according to the present disclosure, it is not essential that the workpiece be irradiated with ultraviolet light from the ultraviolet light source. For example, as shown in FIG. 1(b), a plasma actuator configured so that the ultraviolet light source 102 cannot be directly seen through the opening 106 is also within the scope of the present disclosure. In the plasma actuator according to FIG. 1(b), ozone is decomposed by ultraviolet light from the ultraviolet light source 102, and as a result, an induced flow 105-1 containing active oxygen flows out from the opening 106 and is supplied to the treatment surface 104-1 of the workpiece 104.

[0028] That is, in an active oxygen supply device according to one embodiment of the present disclosure, an induced flow 105 containing ozone from a plasma actuator (plasma generating device) 103 flows out of a housing 107 through an opening 106 and is supplied to a processing surface 104-1 of a workpiece 104, and an ozone decomposition device 102 decomposes the ozone (for example, an ultraviolet light source 102 irradiates the induced flow 105 with ultraviolet light) to generate active oxygen in the induced flow 105, thereby actively supplying active oxygen to a region near the processing surface 104-1, specifically, a spatial region up to a height of about 1 mm from the processing surface (hereinafter also referred to as the "surface region"). Therefore, the generated active oxygen can be supplied to the surface of the workpiece before it is converted into oxygen and water, and as a result, the treatment surface 104-1 of the workpiece 104 is more reliably treated with the active oxygen.

[0029] FIG. 3(a) is a plan view of a plasma actuator according to one embodiment of the present disclosure, observed from the side of the first electrode 203. In FIG. 3(a), the X-axis is an axis parallel to the blowing direction (first direction) of the induced flow 105 from the plasma actuator 103, and the first direction is the +X direction. The Y-axis is an axis perpendicular to the X-axis and extends along the surface of the dielectric, and the +Y direction extends toward the left side of FIG. 3(a). Furthermore, the Z-axis, which is perpendicular to the paper surface, extends along the thickness direction of the plasma actuator, as shown in FIG. 3(b), which is a cross-sectional view of the plasma actuator shown in FIG. 3(a), and the +Z direction extends toward the first electrode 203.

[0030] The first electrode 203 is provided on the first surface of the dielectric 201 so as to cover a part of the surface of the dielectric 201. FIG. 3(c) is a plan view of the plasma actuator shown in FIG. 3(a) as seen from the second electrode side. As shown in FIG. 3(c), the edge of the second electrode 205 on the -X direction side (the second direction side, which is the opposite direction to the first direction) has a portion that extends in the -X direction (second direction) and has a length (width) in the Y-axis direction that is constant in the -X direction (constant along the X axis). A protrusion 301 is provided. Specifically, the convex portion is a portion corresponding to the amplitude (twice the amplitude) 302 of the vibration of the waveform, which has a rectangular wave shape with a constant amplitude in the first direction. In Fig. 3(c), for the convenience of explaining the positional relationship between the second electrode 205 and the first electrode, the first electrode located on the opposite side of the dielectric 201 is shown by a dotted line.

[0031] FIG. 4(a) is a perspective view of the plan view shown in FIG. 3(a), that is, a view assuming that the first electrode 203 and the dielectric 201 are transparent for the convenience of explaining the positional relationship between the first electrode 203 and the second electrode 205. As shown in Figures 3(c), 4(a), and 4(b), the edge 204 on the +X direction side of the first electrode 203 overlaps with the second electrode only at the convex portion 301 of the second electrode 205. Specifically, as shown in Figures 4(a) and 4(b), a distance 401 between the tip portion on the -X direction side (second direction side) of the convex portion 301 of the second electrode 205 and the edge 204 on the +X direction side (first direction side) of the first electrode 203 is greater than 0 µm. In addition, a distance 403 between the edge 204 on the +X direction side (first direction side) of the first electrode 203 and a non-convex portion (the portion closest to the first direction side that serves as the base of the convex portion) 400 on the -X direction side of the second electrode 205 is also greater than 0 µm.

[0032] When a voltage is applied between the first electrode 203 and the second electrode 205, the strongest dielectric barrier discharge occurs at the shortest distance between the two electrodes. For example, as shown in Figures 5(a) and 5(b), when the edge 204 of the first electrode 203 and the edge 501 on the -X direction side of the second electrode are both linear in the -Y to +Y directions, if the edge 204 and the edge 501 are spaced apart, it is necessary to relatively increase the voltage applied between the two electrodes in order to generate a dielectric barrier discharge. Note that when there is a space between them, the amount of overlap is sometimes referred to as being negative. On the other hand, as shown in Figures 6(a) and 6(b), when edge 204 and edge 501 without a convex portion overlap, i.e., when the amount of overlap is positive, the capacitance of the positive actuator increases, and the utilization efficiency of the energy applied between the two electrodes for generating an induced flow may decrease.

[0033] 7(a) and 7(b), when edge 204 and edge 501 are aligned in the X-axis direction, the efficiency of energy utilization for generating an induced flow is maximized. However, adjusting the positions of first electrode 203 and second electrode 205 so that edge 204 and edge 501 are aligned can be a rate-limiting factor in the production process of the plasma actuator.

[0034] On the other hand, in the plasma actuator according to the present disclosure, when the plasma actuator is seen through from the second electrode side, a convex portion 301 extending in the -X direction is provided on the edge portion on the -X direction side (the second direction side that is the opposite direction to the first direction) of second electrode 205. At the same time, second electrode 205 overlaps with edge portion 204 on the +X direction side of first electrode 203 only at convex portion 301 of second electrode 205.

[0035] 6(a) and 6(b), this configuration can suppress an increase in the electrostatic capacitance of the plasma actuator. Furthermore, the induced flow is mainly generated in the portion of the edge 204 of the first electrode 203 that overlaps with the convex portion of the second electrode 205. Therefore, as long as the width of the convex portion 301 is constant in the −X direction in which the convex portion extends, the length of the dielectric barrier discharge and the amount of induced flow generated will hardly change even if the overlap amount 401 between the first electrode 203 and the second electrode 205 changes. Furthermore, the change in power consumption is also small.

[0036] Therefore, when producing the plasma actuator, the positional relationship between the first electrode 203 and the second electrode 205 needs to be controlled more strictly than when the configuration shown in FIGS. 7(a) and 7(b) is used. It is also possible to process a longer processing width (length in the Y-axis direction) with low power consumption. As a result, the active oxygen supply device according to the present disclosure is believed to be able to supply active oxygen to the object to be treated more efficiently and stably, thereby further improving the treatment efficiency of the object to be treated.

[0037] In the plasma actuator according to this embodiment, the length 405 of the convex portion is not particularly limited, but is preferably, for example, 100 μm or more and 10,000 μm or less, and particularly preferably 300 μm or more and 3,000 μm or less. The overlap amount 401 between the first electrode and the second electrode is more than 0 μm and less than the length 405 of the convex portion. A preferable lower limit is, for example, 50 μm. Furthermore, distance 403 between non-convex portion 400 (the portion of the convex portion closest to the +X direction) of the edge portion on the -X direction side of second electrode 205 and edge portion 204 of the first electrode is greater than 0 μm and less than length 405 of the convex portion. In particular, it is preferably 50 μm or more and 5000 μm or less.

[0038] In plasma actuator 103, the shape of the convex portion on the edge of the second electrode is not limited to a rectangle with all four corners at 90° as shown in FIG. 3(c). In other words, as long as the width of the convex portion in the Y-axis direction is equal in the -X direction, the shape is not particularly limited. One example is a rectangle with two pairs of opposite sides parallel to each other and two pairs of opposite angles equal to each other, as shown in FIG. 8(a). Another example is a rectangle with curved sides extending in the -X direction, as shown in FIG. 8(b).

[0039] The shape and number of the protrusions are not particularly limited and may be appropriately determined based on the relationship between the desired amount of induced electric field generated and power consumption. From the viewpoint of achieving a more stable discharge across the edge portion 204, it is preferable that the protrusions are arranged in a continuous manner, with multiple protrusions of approximately the same shape, and it is more preferable that they are arranged in a regular pattern. The term "approximately the same shape" does not need to be completely the same, as long as the shapes are the same to the extent that the effects of the present disclosure are not impaired.

[0040] Preferably, there are multiple protrusions, and as shown in FIG. 4(a), the bases of the multiple protrusions are on the same line segment (Lb) and the tops of the multiple protrusions are on the same line segment (Lt). The line segment Lt connecting the tops of the multiple protrusions and the edge 204 of the first electrode 203 are parallel. More preferably, the line segment Lb connecting the bases of the multiple protrusions, the line segment Lt connecting the tops of the multiple protrusions, and the edge 204 of the first electrode 203 are parallel. This makes it easier to achieve a more stable discharge. The tops of the convex portions are preferably linear, preferably rectangular, and more preferably rectangular wave-shaped.

[0041] The convex portions only need to have a constant width in the second direction, and preferably have a periodic and regular wave shape as shown in Figures 4(a), 8(a), and 8(b). The wavelength of the wave shape is not particularly limited, but is preferably, for example, 0.1 mm to 10 mm, and more preferably 0.5 mm to 5 mm. The amplitude is also not particularly limited, but is, for example, preferably 0.1 mm to 10 mm, and more preferably 0.5 mm to 5 mm.

[0042] As shown in FIG. 4(a), the sum of the width lengths (lengths in the direction perpendicular to the second direction) 406 of the protrusions 301 at the edges on the second direction side of the second electrode in the second direction (−X direction) is L 1 The length 407 of the edge of the second electrode on the second direction side in the direction perpendicular to the second direction is L 2 In this case, L 1 / L 2 is not particularly limited and may be set appropriately based on the relationship between the desired amount of induced generation and power consumption, but is preferably about 0.2 to 0.8, and more preferably about 0.3 to 0.7.

[0043] 4(a) and 4(b), the edge 205-2 on the +X direction side of the second electrode 205 is located further in the +X direction than the +X direction edge 204 of the first electrode 203. Since the second electrode is located extending further in the +X direction than the edge 204 of the first electrode 203, the directionality of the induced flow 105 in the +X direction can be further increased. Furthermore, it is preferable that the edge 204 on the first direction side of the first electrode 203 has a linear shape that extends perpendicular to the first direction and in a direction along the first surface of the dielectric (i.e., the Y-axis direction), which makes the generation of the discharge and the induced flow containing ozone more stable.

[0044] The materials constituting the first electrode and the second electrode are not particularly limited as long as they are materials with good conductivity. For example, metals such as copper, aluminum, stainless steel, gold, silver, and platinum, as well as metals plated or vapor-deposited on these, conductive carbon materials such as carbon black, graphite, and carbon nanotubes, and composite materials obtained by mixing these with resins, etc., can be used. The materials constituting the first electrode and the second electrode may be the same or different.

[0045] Among these, from the viewpoint of avoiding electrode corrosion and achieving uniform discharge, the material constituting the first electrode is preferably aluminum, stainless steel, or silver, and for the same reason, the material constituting the second electrode is preferably aluminum, stainless steel, or silver. The first electrode and the second electrode may have any shape, such as a flat plate, a wire, or a needle, without any particular limitation. Preferably, the first electrode has a flat plate shape. Preferably, the second electrode has a flat plate shape. When at least one of the first electrode and the second electrode has a flat plate shape, the aspect ratio of the plate (length of long side / length of short side) is preferably 2 or more.

[0046] In a preferred embodiment, at least one of the first and second electrodes has an apex angle of 45° or less (i.e., the electrode is sharp), but this is not limiting. Although Fig. 2 shows a case where the apex angles of the first and second electrodes are both 90°, embodiments in which the apex angles exceed 45° are also included in the present disclosure.

[0047] The dielectric is not particularly limited as long as it is a material with high electrical insulation. For example, resins such as polyimide, polyester, fluororesin, silicone resin, acrylic resin, and phenolic resin, glass, ceramics, and composite materials in which these are mixed with resin, etc. can be used. Among these, ceramics, glass, and silicone resin are preferably used from the viewpoints of strength and insulation. In particular, silicone resin is flexible, which allows for greater freedom in the shape of the plasma actuator.

[0048] Furthermore, assuming that the first electrode and the second electrode are electrically insulated, the shorter the shortest distance between them, the easier it is for a dielectric barrier discharge to occur. Therefore, the thickness of the dielectric portion interposed between the first electrode 203 and the second electrode 205 is preferably thin enough to prevent dielectric breakdown when a voltage is applied to both electrodes. Specifically, for example, when an AC voltage of 100 to 100 kVpp is applied, the thickness of the dielectric portion is preferably 10 μm to 1000 μm, more preferably 10 μm to 200 μm. Furthermore, the shortest distance between the first electrode and the second electrode is preferably 200 μm or less, more preferably 100 μm to 200 μm.

[0049] The thickness of the electrodes is not particularly limited for either the first electrode or the second electrode, but can be 10 μm to 1000 μm. If the thickness is 10 μm or more, the resistance is low and plasma generation becomes easier. If the thickness is 1000 μm or less, electric field concentration occurs easily, making plasma generation easier. The length of the electrode in the first direction (X-axis direction) (electrode width) is not particularly limited for both the first electrode and the second electrode, but can be 1000 μm or more.

[0050] Furthermore, if the edge of the second electrode is exposed, plasma may also be generated from the edge of the second electrode, resulting in an induced flow in the opposite direction to the induced flow 105 originating from the first electrode. In the active oxygen supplying device according to this embodiment, it is preferable to keep the ozone concentration in the internal space of the active oxygen supplying device, other than the surface region of the workpiece, as low as possible. It is also preferable to prevent the generation of a gas flow within the container that would disrupt the induced flow 105. Therefore, it is preferable to prevent the generation of an induced flow originating from the second electrode. Therefore, it is preferable that the second electrode 205 be covered with a dielectric such as a dielectric substrate 206, as shown in FIGS. 2(a) and 3(b), or embedded in a dielectric 201, to prevent plasma generation from the edge of the second electrode.

[0051] The second electrode may be embedded to an extent that plasma generation from the edge of the second electrode is prevented, and for example, a portion of the surface of the second electrode may be exposed, and the exposed surface of the second electrode may form the same plane as the dielectric substrate 206 or the dielectric 201. It is preferable that the edge of the second electrode is covered with the dielectric substrate 206 or the dielectric 201. Therefore, for example, the plasma actuator is preferably an SDBD (single dielectric barrier discharge) plasma actuator.

[0052] Induced flow 105 containing high-concentration ozone flows in the direction of a jet-like flow caused by surface plasma from edge 204 of first electrode 203 along exposed portion 201-1 of the first surface of dielectric 201, that is, in the direction from edge 204 of first electrode 203 along exposed portion 201-1 of the first surface of the dielectric. This induced flow is a gas flow containing high-concentration ozone, with a speed of several m / s to several tens of m / s. The voltage applied between the first electrode 203 and the second electrode 205 of the plasma actuator is not particularly limited as long as it can generate plasma in the plasma actuator. Although either a DC voltage or an AC voltage may be used, an AC voltage is preferred. It is also a preferred embodiment that the voltage is a pulse voltage.

[0053] Furthermore, the amplitude and frequency of the voltage can be appropriately set to adjust the flow rate of the induced flow and the ozone concentration in the induced flow, and in this case, the amplitude and frequency can be appropriately selected from the viewpoints of generating an ozone concentration in the induced flow required to generate an effective active oxygen concentration or amount of effective active oxygen according to the purpose of the treatment, and supplying the generated active oxygen to the surface region of the workpiece while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment. For example, the amplitude of the voltage can be set to 1 kV to 100 kV. Furthermore, the frequency of the voltage can be set to preferably 1 kHz or higher, more preferably 10 kHz to 100 kHz.

[0054] When the voltage is an AC voltage, the waveform of the AC voltage is not particularly limited, and a sine wave, square wave, triangular wave, etc. can be used, but a square wave is preferable from the viewpoint of the speed of the voltage rise. The duty ratio of the voltage can also be selected appropriately, but a fast voltage rise is preferred. Preferably, the voltage is applied so that the rise time of the voltage from the bottom to the peak of the wavelength amplitude is 400,0000 V / second or more. The value (voltage / film thickness) obtained by dividing the amplitude of the voltage applied between the first electrode 203 and the second electrode 205 by the film thickness of the dielectric 201 is preferably 10 kV / mm or more.

[0055] <Ozone decomposition device> The active oxygen supply device or activation treatment device includes an ozone decomposition device 102. The ozone decomposition device decomposes ozone contained in the induced flow to generate active oxygen in the induced flow. The decomposition device may be one that acts on the ozone contained in the induced flow and decomposes the ozone. The ozone decomposition device is preferably one that can decompose the ozone without disturbing the flow of the induced flow. The ozone decomposition device is preferably at least one device selected from the group consisting of an ultraviolet light source that irradiates an ozone-containing induced flow with ultraviolet light to generate active oxygen in the induced flow, a heating device that heats an ozone-containing induced flow to generate active oxygen in the induced flow, and a humidifying device that humidifies an ozone-containing induced flow to generate active oxygen in the induced flow. The ozone decomposition device may be a combination of these. For example, the ozone decomposition device may be a device that heats the induced flow while irradiating it with ultraviolet light, or a device that irradiates the induced flow with ultraviolet light and heats the induced flow while humidifying the inside of the housing. The ozone decomposition device is more preferably an ultraviolet light source. Each device is described below.

[0056] <Ultraviolet light source and ultraviolet light> The ultraviolet light source is not particularly limited as long as it can irradiate ultraviolet light capable of exciting ozone and generating active oxygen. Furthermore, the ultraviolet light source is not particularly limited as long as it has an ultraviolet wavelength and irradiance required to excite ozone and obtain an effective active oxygen concentration or amount according to the purpose of treatment. For example, since the peak value of the light absorption spectrum of ozone is 260 nm, the peak wavelength of the ultraviolet light is preferably 220 nm to 310 nm, more preferably 253 nm to 285 nm, and even more preferably 253 nm to 266 nm. Specific examples of ultraviolet light sources that can be used include low-pressure mercury lamps, which are made by sealing mercury together with inert gases such as argon or neon in quartz glass, cold cathode ultraviolet lamps (UV-CCL), and ultraviolet LEDs. The wavelength of the low-pressure mercury lamp or cold cathode ultraviolet lamp should be selected from wavelengths such as 254 nm. On the other hand, the wavelength of the ultraviolet LED should be selected from wavelengths such as 265 nm, 275 nm, and 280 nm from the standpoint of output performance.

[0057] <Heating device> The heating device 102 is not particularly limited as long as it can provide thermal energy that excites the ozone in the induced flow and generates active oxygen. Since thermal decomposition of ozone begins at about 100°C, a device that can heat the induced flow to about 120°C is preferred. On the other hand, temperatures above 120°C may cause thermal degradation such as melting or decomposition depending on the material being treated, so a temperature of 200°C or less is preferred. A temperature of 100 to 140°C is preferred, and a temperature of 110 to 130°C is more preferred.

[0058] The heating device is not particularly limited, and examples that can be used include ceramic heaters, cartridge heaters, sheath heaters, electric heaters, and oil heaters. In the case of a device including a metal heating element, the heating element is preferably made of a material with excellent oxidation resistance, such as a nichrome alloy or tungsten. A cartridge heater is preferred.

[0059] <humidifier> The humidifier 102 is not particularly limited as long as it can humidify the interior of the housing, incorporate water into the induced flow, and generate active oxygen in the induced flow by decomposing ozone in the induced flow with water. Here, humidification means providing moisture to the target, and the form of the moisture is not particularly limited and may be at least one selected from the group consisting of gas, liquid, and solid. Furthermore, any known water can be used as the water used to provide moisture, and it may contain substances other than water.

[0060] The humidifier is not particularly limited, and examples thereof include an evaporative humidifier and a mist humidifier. To prevent the humidity in the vicinity of the plasma actuator from increasing, a humidifier supplies moisture. A humidifier that has directivity in terms of direction (hereinafter simply referred to as directivity) is preferable. By having a humidifier that has directivity, it is possible to efficiently humidify the vicinity of the induced flow and the vicinity of the surface of the workpiece without increasing the humidity near the plasma actuator. Known methods can be suitably used to impart directionality to a humidifier. For example, a method of generating an airflow by providing a fan and transporting moisture in the direction of the airflow, or a method of applying appropriate pressure to moisture using an air pump or the like to eject the moisture in the desired direction, are possible. It is preferable to direct the moisture in the same direction (first direction) as the induced flow so as not to disturb the flow of the induced flow.

[0061] <Arrangement of plasma actuator, ozone decomposition device, and object to be treated> In active oxygen supply device 101, the position of plasma actuator 103 that generates an induced flow containing ozone is not particularly limited as long as it is disposed so that induced flow 105 caused by ultraviolet light irradiated from ultraviolet light source 102, which is an ozone decomposition device, flows out of the housing through an opening and is supplied to the surface of the object to be treated while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment. The same applies when the ozone decomposition device is a heating device or a humidifying device. For example, the plasma actuator and the ozone decomposition device may be arranged so that the induced flow 105 containing the generated active oxygen is supplied to the surface of the object to be treated over the shortest distance.

[0062] Also, for example, it is preferable to arrange the plasma actuator so that the processing surface 104-1 of the workpiece is included on an extension line extending from the edge 204 on the first direction side of the first electrode 203 of the plasma actuator along the first surface (exposed portion 201-1) of the dielectric. For example, it is preferable that the extension line contacts the processing surface 104-1. It is also preferable that an extension line extending from the edge of the first direction side of the first electrode 203 of the plasma actuator along the first surface of the dielectric (the same as the +X direction) is directed toward the opening, which makes it easier for the induced flow to flow out of the housing through the opening.

[0063] Furthermore, when the opening of the active oxygen supplying device is directed vertically downward, the narrow angle θ (hereinafter also referred to as the plasma actuator incident angle or PA incident angle; see FIG. 9(a)) formed by an extension line 201-1-1 extending from the edge of the first electrode of the plasma actuator along the exposed portion 201-1 of the first surface of the dielectric and the horizontal plane (a plane perpendicular to the vertical direction) is defined as θ. The narrow angle θ is not particularly limited as long as it is an angle at which an induced flow can be actively supplied to the surface region of the workpiece while maintaining the amount of available active oxygen or the amount of available active oxygen according to the purpose of the treatment, or an angle at which treatment can be performed with active oxygen. However, it is preferably 0° to 90°, and more preferably 30° to 70°. By arranging the plasma actuator and the ozone decomposition device as described above, an induced flow containing active oxygen with a certain flow velocity can be locally supplied to an area near the surface of the workpiece, or the workpiece can be treated with active oxygen. In addition, the induced flow flowing out from the opening flows along the surface of the workpiece, so that parts of the workpiece surface other than the part facing the opening are also exposed to the induced flow containing active oxygen. This allows a wider area of ​​the workpiece surface 104-1 to be treated with active oxygen.

[0064] The plasma actuator is preferably positioned so that the treatment surface 104-1 of the workpiece is included on an extension of the first direction (the direction in which the induced flow is blown out). When the opening of the active oxygen supplying device is oriented vertically downward, the angle θ' is defined as the angle between the first direction (the direction in which the induced flow is blown out) and a horizontal plane (a plane perpendicular to the vertical direction). The angle θ' is preferably 0° to 90°, and more preferably 30° to 70°.

[0065] The ozone decomposition device generates active oxygen in the induced flow and is arranged so that the surface of the object to be treated can be treated while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment. As long as it is placed, there are no other particular restrictions. As described above, an induced flow containing ozone is actively supplied to a region near the surface of the workpiece. Furthermore, if the ozone decomposition device is an ultraviolet light source, active oxygen can be generated in the induced flow by irradiating the induced flow with ultraviolet light. Therefore, by irradiating the induced flow with ultraviolet light, ozone is excited, and the induced flow in which active oxygen is generated can be actively supplied to the surface of the workpiece, thereby significantly increasing the active oxygen concentration or amount on the surface of the workpiece. The relative positions of the ozone decomposition device and the plasma actuator are not particularly limited, as long as they are each positioned so that active oxygen is generated in the induced flow and treatment can be carried out on the surface of the workpiece while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment.

[0066] Furthermore, the distance between the ozone decomposition device and the plasma actuator also varies depending on the purpose of the treatment, and therefore cannot be generally defined. For example, the distance between the surface of the dielectric of the plasma actuator facing the ozone decomposition device is preferably 10 mm or less, and more preferably 4 mm or less. However, the plasma actuator does not need to be located within approximately 10 mm of the ozone decomposition device. As long as the active oxygen in the induced flow can be adjusted to an effective concentration according to the purpose of the treatment in relation to factors that can decompose ozone, such as the illuminance and wavelength of ultraviolet light, as described below, the distance between the ozone decomposition device and the plasma actuator is not particularly limited. It is also a preferred embodiment that at least one of the ozone decomposition device and the plasma actuator is provided with a moving means, so that at least one of the ozone decomposition device and the plasma actuator is movable so that the degree of ozone decomposition is uniform.

[0067] The relative positions of the active oxygen supply device and the workpiece to be treated may be such that at least one of them is positioned so that active oxygen is generated in the induced flow and the surface of the workpiece to be treated is exposed to the induced flow in which the effective active oxygen concentration or amount of effective active oxygen according to the purpose of the treatment is maintained.

[0068] Furthermore, when the ozone decomposition device is an ultraviolet light source, the ultraviolet light source may be located at a position where the ultraviolet light can irradiate the surface of the object to be treated, or may be located at a position where the ultraviolet light cannot irradiate the surface of the object to be treated. Even when the ultraviolet light from the ultraviolet light source cannot irradiate the surface of the object to be treated, the treatment device using active oxygen according to this embodiment can treat the surface by exposing it to the active oxygen in the induced flow. Similarly, when the ozone decomposition device is a heating device, the heating device may be located in a position where it can heat the surface of the object to be treated, or in a position where it cannot heat the surface of the object to be treated. Furthermore, in sterilization treatment using ultraviolet light, only the surface irradiated with ultraviolet light is sterilized. However, in sterilization treatment using the active oxygen supplying device according to the present disclosure, bacteria present in positions that can be reached by active oxygen can be sterilized. Therefore, for example, even bacteria present between fibers, which are difficult to sterilize by external ultraviolet light irradiation, can be sterilized.

[0069] On the other hand, if the ultraviolet light source is positioned so that it can irradiate the surface of the workpiece placed outside the housing through the opening, the undecomposed ozone present in the induced flow can be decomposed in situ on the workpiece surface, generating active oxygen on the workpiece surface, thereby further improving the degree and efficiency of the treatment. In this case, the illuminance of ultraviolet light on the surface of the workpiece or at the opening is not particularly limited, but it is preferable to set the illuminance of ultraviolet light on the surface of the workpiece or at the opening to a level that can decompose ozone contained in the induced flow, generate active oxygen in the induced flow, and produce an effective active oxygen concentration or amount according to the purpose of the treatment. Specifically, for example, a specific example of the illuminance of ultraviolet light on the surface of the workpiece or at the opening is 40 μW / cm. 2 It is preferable that the power is 100 μW / cm or more. 2 More preferably, it is 400 μW / cm or more. 2 More preferably, it is 1000 μW / cm or more. 2The upper limit of the illuminance is not particularly limited, but is, for example, 10,000 μW / cm 2 It can be as follows:

[0070] Furthermore, the distance between the ozonolysis device and the surface of the workpiece to be treated can be adjusted depending on the purpose of the treatment and is not particularly limited, but considering the lifespan of the active oxygen contained in the induced flow, it is preferably 10 mm or less, more preferably 4 mm or less. However, the workpiece does not need to be placed so that its treatment surface is within about 10 mm of the ozonolysis device, and the distance between the ozonolysis device and the workpiece to be treated is not particularly limited as long as the active oxygen in the induced flow can be adjusted to an effective concentration according to the purpose of the treatment in relation to factors that can decompose ozone, such as ultraviolet irradiance.

[0071] Furthermore, in a plasma actuator, the amount of ozone generated per unit time when the ozone in the induced flow is not decomposed by an ozone decomposition device is preferably, for example, 15 μg / min or more. More preferably, it is 30 μg / min or more. There is no particular upper limit to the amount of ozone generated, but it is, for example, 1000 μg / min or less. That is, the preferred range is 15 μg / min or more and 1000 μg / min or less.

[0072] The flow velocity of the induced flow may be, for example, a velocity that can actively supply the generated active oxygen to the surface region of the workpiece while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment, for example, about 0.01 m / s to 100 m / s as described above. As described above, the ozone concentration in the induced flow generated by the plasma actuator and the flow rate of the induced flow can be controlled by the thickness and material of the electrodes and dielectric, the type, amplitude, frequency, etc. of the applied voltage.

[0073] <Housing and openings> The active oxygen supplying device of the present disclosure includes a housing 107 having at least one opening 106, an ozone decomposing device 102 disposed inside the housing, and a plasma actuator 103. The opening is not particularly limited as long as it allows the induced flow 105 containing active oxygen generated by the plasma actuator 103 and the ozone decomposition device 102 to flow out of the housing 107. The size of the opening, the position of the opening, and the relative position of the opening and the workpiece can be selected as appropriate, for example, so that the generated active oxygen can be actively supplied to the surface region of the workpiece while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment.

[0074] Furthermore, the distance between the plasma actuator and the opening is preferably short so that the active oxygen in the induced flow can be used more effectively for the target treatment. Therefore, it is preferable to position the plasma actuator as close to the opening as possible. On the other hand, to protect the plasma actuator, it is also preferable to position it at a setback from the opening. As an example, it is preferable to position the plasma actuator on the inner wall of the housing so that the end of the plasma actuator closest to the opening is located 0.5 mm to 1.5 mm from the edge of the opening on the inner wall of the housing.

[0075] The active oxygen supplying device of the present disclosure can be used not only for sterilizing the object to be treated but also for general applications that require supplying active oxygen to the object to be treated. For example, the active oxygen supplying device of the present disclosure can be used for deodorizing the object to be treated, bleaching the object to be treated, and hydrophilizing the surface of the object to be treated. Furthermore, the treatment device using active oxygen according to the present disclosure not only sterilizes the object to be treated, but also, for example, deodorizes the object to be treated, bleaches the object to be treated, makes the object to be treated hydrophilic, etc. It can also be used for surface treatment.

[0076] The present disclosure also provides a treatment method for treating a surface of a workpiece with active oxygen, comprising: preparing the treatment device using active oxygen; a step of placing the prepared active oxygen treatment device and the object to be treated in relative positions such that the surface of the object to be treated is exposed when the induced flow containing the active oxygen is caused to flow out from the opening; and a step of discharging the induced flow containing the active oxygen from the opening to treat the surface of the object with the active oxygen.

[0077] In this disclosure, "effective active oxygen concentration or amount of effective active oxygen" refers to the active oxygen concentration or amount of active oxygen required to achieve a purpose for the object to be treated, such as sterilization, deodorization, bleaching, or hydrophilization, and can be adjusted appropriately according to the purpose using the electrodes and dielectric thickness and material that make up the plasma actuator, the type, amplitude, and frequency of the voltage applied, the degree of ozone decomposition by the ozone decomposition device (ultraviolet irradiance and irradiation time, heating temperature and heating time, and amount of water for humidification and humidification time), the PA incidence angle, etc. [Example]

[0078] The present disclosure will be described in more detail below using examples and comparative examples, but the aspects of the present disclosure are not limited thereto.

[0079] Example 1 1. Preparation of the Active Oxygen Supply Apparatus A first electrode was formed by attaching a piece of aluminum foil measuring 2.5 mm in length, 15 mm in width, and 100 μm in thickness to a first surface of a glass plate (5 mm in length, 18 mm in width (depth direction in Figure 1), and 150 μm in thickness) using adhesive tape. A second electrode was formed by attaching a piece of aluminum foil measuring 3 mm in length, 15 mm in width, and 100 μm in thickness to a second surface of the glass plate using adhesive tape, diagonally opposite the aluminum foil attached to the first surface. The second surface, including the second electrode, was then covered with polyimide tape. In this way, plasma actuator A-1 was fabricated, in which the +X-direction edge of the first electrode and the -X-direction edge of the second electrode overlapped over a width of 0.5 mm, sandwiching the dielectric (glass plate) between them. Two such plasma actuators were prepared.

[0080] The first and second electrodes of the plasma actuator had the shapes shown in Figures 3(a) to 3(c). That is, the edge 204 on the +X side of the first electrode was linear and extended in the Y-axis direction, and the edge on the -X side of the second electrode had periodic rectangular convex portions (rectangular waveform with an amplitude of 1 mm, a wavelength of 2 mm, and a duty ratio of 0.5). The overlap amount 401 shown in Figure 4(a) was +0.3 mm. The overlap of the electrodes in the perspective view resulted in a discharge length of 8 mm. The discharge length corresponds to the sum of the widths of the convex parts of the first electrode and the overlapping second electrode, i.e., L 1 / L 2 was 8mm / 15mm ≒ 0.53.

[0081] Next, a case made of ABS resin with a height of 25 mm, a width of 20 mm, a length of 170 mm, and a thickness of 2 mm, and a cross-sectional shape of a substantially trapezoid as shown in FIG. 9(a), was prepared as the housing 107 of the active oxygen supplying device 101. As shown in FIG. 9(b), which is a plan view seen from the opening side, the case had a rectangular opening 106 with a width of 7 mm and a length of 15 mm, which was symmetrical about the center in the longitudinal direction (the dashed line in FIG. 9(b)). Next, two plasma actuators 103 fabricated previously were fixed to the hypotenuse portions of the inner wall of the housing 107 in FIG. 9(a). The angle θ (the angle θ (as described above)) formed by the intersection of the extension line 201-1-1 of the plasma actuator 103 in the direction along the exposed portion 201-1 of the first surface of the dielectric 201 and the treatment surface 104-1 of the workpiece was adjusted. A) (equivalent to the incident angle) was 45°. The mounting position of plasma actuator 103 in the longitudinal direction of the housing was set so that the center of the longitudinal direction of the housing coincided with the center of the longitudinal direction (18 mm) of the plasma actuator, as shown in Figure 9(b).

[0082] Furthermore, an ultraviolet lamp 102 (cold cathode ultraviolet lamp, product name: UW / 9F89 / 9, manufactured by Stanley Electric Co., Ltd., cylindrical with a diameter of 9 mm, peak wavelength = 254 nm) was placed inside the housing. The ultraviolet lamp 102 was positioned so that the distance between the ultraviolet lamp 102 and the exposed portion 201-1 of the first surface of the dielectric 201 of the plasma actuator (reference numeral 903 in FIG. 9(a)) was 2 mm, and the distance between the ultraviolet light source and the surface of the flat plate facing the ultraviolet light source (reference numeral 901 in FIG. 9(a)) when the flat plate was abutted against the opening 106 of the housing 107 was 3 mm. In this way, an active hydrogen supply device (treatment device using active oxygen) according to this example was produced.

[0083] An illuminance meter (trade name: Spectroradiometer USR-45D, manufactured by Ushio Inc.) was placed at the position of the opening 106, which serves as the supply port for active oxygen in the active oxygen supply device 101, to measure the illuminance of ultraviolet light. The integrated value of the spectrum showed a value of 1370 μW / cm 2 At this time, the plasma actuator was not powered on to avoid the influence of UV blocking by ozone generated from the plasma actuator. Since the workpiece was placed, for example, at the position of the opening 106, the UV illuminance measured under these conditions was considered to be the UV illuminance on the surface of the workpiece.

[0084] Next, to calculate the amount of ozone generated from the plasma actuator 103, the active oxygen supply device 101 was placed in a sealed container (not shown) with a volume of 1 liter. The sealed container had a hole that could be sealed with a rubber stopper, allowing the gas inside to be aspirated using a syringe. Then, without turning on the ultraviolet lamp, a voltage having a sine waveform with an amplitude of 3.2 kV and a frequency of 80 kHz was applied to the plasma actuator 103. One minute later, 100 ml of gas was sampled from the sealed container. The sampled gas was sampled using an ozone detector tube (product name: 182SB, manufactured by Komyo Rikagaku Kogyo Co., Ltd.), and the measured ozone concentration (PPM) contained in the induced flow from the plasma actuator 103 was measured. Using the measured ozone concentration, the amount of ozone generated per unit time was calculated using the following equation:

number

[0085] As a result, the amount of ozone generated per unit time was 24 μg / min. Finally, the amount of ozone generated was measured when both the plasma actuator 103 and the ultraviolet lamp 102 were operating. As described above, the operating conditions for the plasma actuator 103 were such that 24 μg / min of ozone was generated when only the plasma actuator 103 was operating. Furthermore, as described above, the operating conditions for the ultraviolet lamp 102 were such that 1370 μW / cm was generated when only the ultraviolet lamp 102 was operating. 2 As a result, the amount of ozone generated when both the plasma actuator 103 and the ultraviolet lamp 102 were operating was 3 μg / min. The decrease of 21 μg / min from 24 μg / min is thought to be the amount of ozone that was converted into active oxygen. In addition, when the discharge state was visually confirmed, it was found that the first electrode and the second electrode overlapped. At the edge 204 of the first electrode, a uniform discharge was obtained both spatially and temporally.

[0086] 2-1. Active oxygen detection test (methylene blue absorbance) The presence or absence of active oxygen in the induced flow flowing out from the opening was confirmed by the decolorization of methylene blue (see Non-Patent Document 1). Methylene blue is a crystalline powder with a blue luster, and because it is soluble in water and ethanol, it is used as a dye or indicator in solution. Methine blue reacts with active oxygen, decomposing and losing its blue color. Therefore, the presence or absence of active oxygen in the induced flow can be confirmed by the decolorization of methylene blue (disappearance of the blue color). Specifically, the following procedure was performed. Methylene blue (special grade, manufactured by Kanto Chemical) and distilled water were mixed to prepare a 0.01% methylene blue aqueous solution. 15 ml of this methylene blue aqueous solution was placed in a Petri dish (AB4000, manufactured by Eiken Scientific, cylindrical, 88 mm diameter). The liquid surface of the methylene blue aqueous solution in the Petri dish was regarded as the treatment surface 104-1 of the treatment object, and the active oxygen supply device 101 was positioned so that the distance 905 in Figure 9(a) between this liquid surface and the active oxygen supply device 101 was 1.4 mm.

[0087] Next, an AC voltage of 3.2 kV and a frequency of 80 kHz having a sine waveform was applied between the first and second electrodes of the plasma actuator of the active oxygen supply device, and the ultraviolet lamp was turned on to supply the induced flow flowing out from the opening toward the liquid surface for 30 minutes. Note that the ultraviolet lamp was used when the illuminance at the position of the liquid surface was 1370 μW / cm without turning on the power to the plasma actuator. 2 It was adjusted so that After irradiation with the induced flow, the methylene blue solution was transferred from the dish to a cell, and the change in methylene blue light absorption was measured using a spectrophotometer (product name: V-570; manufactured by JASCO). Because methylene blue has a strong absorption at a wavelength of 664 nm, the degree of methylene blue decolorization can be calculated from the change in absorbance at this wavelength. In this test, distilled water alone was placed in the reference cell, and the 0.01% methylene blue solution before irradiation with the induced flow was placed in the sample cell. The absorbance was measured at 2.32 Abs. In contrast, the absorbance of the methylene blue solution after treatment with the activated oxygen supply device was 0.05 Abs. Therefore, the decrease in absorbance at 664 nm after treatment relative to the absorbance of methylene blue before treatment was ((2.32 - 0.05) / 2.32) × 100 = 97.8%.

[0088] 2-2. Treatment (sterilization) test Using the active oxygen supplying device 101 according to this embodiment, a sterilization test for Escherichia coli was carried out in the following manner. All instruments used in this sterilization test were sterilized with high-pressure steam using an autoclave. This sterilization test was also carried out in a clean bench. First, Escherichia coli (trade name "KWIK-STIK (Escherichia coli) ATCC8739)", manufactured by Microbiologics) was placed in an Erlenmeyer flask containing LB medium (2 g of tryptone, 1 g of yeast extract, 1 g of sodium chloride, and distilled water to make 200 ml), and cultured at 37°C for 48 hours with shaking at 80 rpm. After the culture, the E. coli bacterial solution contained 9.2 x 10 9 (CFU / ml). After this incubation, 0.010 ml of the bacterial solution was dropped onto a 3 cm long, 1 cm wide piece of qualitative filter paper (product number: No. 5C, manufactured by Advantec Co., Ltd.) using a micropipette to prepare sample No. 1. The bacterial solution was dropped onto only one side of the filter paper. Sample No. 2 was prepared in the same manner.

[0089] Next, Sample No. 1 was immersed for 1 hour in a test tube containing 10 ml of buffer solution (trade name: Gibco PBS; Thermo Fisher Scientific). Note that the time from dropping the bacterial solution onto the filter paper to immersing it in the buffer solution was set to 60 seconds to prevent the bacterial solution on the filter paper from drying out. Next, 1 ml of the buffer solution after immersion of Sample No. 1 (hereinafter also referred to as "1 / 1 solution") was added to a test tube containing 9 ml of buffer solution to prepare a diluted solution (hereinafter referred to as "1 / 10 diluted solution"). In the same manner, except that the dilution ratio was changed, 1 / 100 diluted solution, 1 / 1000 diluted solution, and 1 / 10000 diluted solution were prepared. Next, 0.050 ml of the 1 / 1 solution was taken and smeared onto a stamp medium (Petan Check 25PT1025, Eiken Kasei Co., Ltd.). This procedure was repeated to create two stamp media smeared with the 1 / 1 solution. The two stamp media were placed in an incubator (trade name: IS600, Yamato Scientific Co., Ltd.) and cultured at 37°C for 24 hours. The number of colonies that appeared on the two stamp media was counted, and the average was calculated.

[0090] 1 / 10 diluted solution, 1 / 100 diluted solution, 1 / 1000 diluted solution and 1 / 10000 diluted solution In the same manner as above, two smeared stamp culture media were prepared for each dilution and cultured. The number of colonies that appeared on each stamp medium for each dilution was then counted, and the average value was calculated. The results are shown in Table 1-1. [Table 1-1]

[0091] From the results in Table 1-1 above, the number of colonies when the 1 / 100 diluted solution was cultured was 54. Therefore, the number of bacteria present in 0.050 ml of the 1 / 1 solution of sample No. 1 was 54 x 10 2 =5400 (CFU).

[0092] Next, the following procedure was carried out on sample No. 2. A recess measuring 3.5 cm in length, 1.5 cm in width, and 1.2 mm in depth was made in the center of a plastic flat plate measuring 30 cm in length, 30 cm in width, and 5 mm in thickness. A filter paper measuring 3.5 cm in length and 1.5 cm in width was placed in the recess. Sample No. 2 was placed on this filter paper so that the bacterial liquid droplet surface faced the filter paper placed at the bottom of the recess. An active oxygen supply device was then placed on the top surface of the plastic plate so that the longitudinal center of its opening coincided with the longitudinal center of the recess and the width of the opening was 1.2 mm. The center of the direction of the plate was aligned with the center of the short side of the recess. The distance 905 (the distance from the tip of the plasma actuator on the opening side to the surface of the filter paper facing the ultraviolet lamp) was set to 1.4 mm.

[0093] Furthermore, since the depth of the recess was 1.2 mm and the thickness of the filter paper was approximately 0.2 mm, there was no direct contact between the bacterial solution-adhered surface of each sample and the opening of the active oxygen supplying device. Next, an AC voltage having a sine waveform of 3.2 kVpp and a frequency of 80 kHz was applied between both electrodes of the active oxygen supplying device, and the ultraviolet lamp was turned on to supply an induced flow toward the filter paper. The supply time (treatment time) was 2 seconds. The ultraviolet lamp had an illuminance of 1370 μW / cm2 measured on the surface of the filter paper facing the ultraviolet lamp. 2 It was adjusted so that

[0094] In addition, in the treatment process using the active oxygen supply device, the time from dropping the bacterial solution onto the filter paper to immersing it in the buffer solution was set to 60 seconds to prevent the filter paper onto which the bacterial solution had been dropped from drying out as much as possible. After the treatment, Sample No. 2 was placed in 10 ml of buffer solution (commercial The specimen was immersed in a test tube containing Gibco PBS (Thermo Fisher Scientific) for 1 hour. Then, 1 ml of the buffer solution (hereinafter referred to as "1 / 1 solution") was added. A dilution (1 / 10 dilution) was prepared by placing the sample in a test tube containing 9 ml of buffer. In the same manner, except for changing the dilution ratio with buffer, 1 / 100 dilution, 1 / 1000 dilution, and 1 / 10000 dilution were prepared.

[0095] Next, 0.050 ml was taken from the 1 / 1 solution and used as a stamp medium (trade name: Petanche) This procedure was repeated to obtain a 1 / 1 solution. Two stamp plates were prepared with the smeared 1 / 100 solution. A total of two stamp plates were placed in an incubator (trade name: IS600; manufactured by Yamato Scientific Co., Ltd.) and cultured at 37°C for 24 hours. The number of colonies that appeared on each stamp plate for the 1 / 1 solution was counted and the average value was calculated. The same procedure was repeated for the 1 / 10 diluted solution, 1 / 100 diluted solution, 1 / 1000 diluted solution, and 1 / 10000 diluted solution. Similarly, two smeared stamp media were prepared for each dilution and cultured. The number of colonies that appeared on each stamp media for each dilution was counted and the average value was calculated. The results are shown in Table 1-2 below. [Table 1-2]

[0096] As shown in Table 1-1, the number of bacteria in 0.050 ml of the 1 / 1 solution of sample No. 1, which was not treated with the active oxygen supply device, was 5,400 (CFU), while after treatment, The number of bacteria in 0.050 ml of the 1 / 1 solution for sample No. 2 was 0 (CFU). From this, it was found that 100.00% ((5400-0 / 5400) x 100) sterilization was achieved by 2 seconds of treatment using the active oxygen supplying device according to this example.

[0097] 2-3. Current consumption test The first and second electrodes of plasma actuator A-1 were connected to a high-frequency, high-voltage inverter, which was then connected to a DC power supply (programmable multi-output power supply) (product name: PPS303; manufactured by AS ONE Corporation). A DC voltage of 20 V was applied to the DC power supply, and an AC voltage of 3 kVpp was output from the high-frequency, high-voltage inverter to the plasma actuator. The DC current consumed at this time was measured using an ammeter built into the DC power supply. The result was 0.060 A.

[0098] Example 2 Plasma actuator A-2 was fabricated in the same manner as plasma actuator A-1, except that the overlap between the first and second electrodes was changed from 0.3 mm to 0.7 mm. An active oxygen supplying device was then fabricated in the same manner as in Example 1, except that this plasma actuator A-2 was used, and was subjected to evaluation.

[0099] Example 3 The convex shape of the edge of the second electrode on the -X direction side was made into a parallelogram shape as shown in Figure 8(a). Specifically, the convex shape was a parallelogram with a height of 2 mm, a width of 1 mm, and an acute angle of 75 degrees, and had an amplitude of 1 mm, a wavelength of 2 mm, and a duty ratio of 0.5. Other than these, plasma actuator B-1 was fabricated in the same manner as plasma actuator A-1. Therefore, The overlap amount between the first electrode and the second electrode was 0.3 mm. An active oxygen supplying device was produced in the same manner as in Example 1 except that this plasma actuator B-1 was used, and was subjected to evaluation.

[0100] Example 4 Plasma actuator B-2 was fabricated in the same manner as plasma actuator B-1, except that the overlap between the first electrode and the second electrode was changed to 0.7 mm. An active oxygen supplying device was then fabricated in the same manner as in Example 1, except that this plasma actuator B-2 was used, and was subjected to evaluation.

[0101] Example 5 The convex shape of the edge of the second electrode on the -X direction side was shaped as shown in Figure 8(b). Specifically, this shape was a straight line 2 mm high and 1 mm wide connected by two parallel curves, with an amplitude of 1 mm, a wavelength of 2 mm, and a duty ratio of 0.5. The curve shape was a sine wave with nodes at both ends, an amplitude of 0.3 mm, and a wavelength of 2 mm. Other than these, plasma actuator C-1 was fabricated in the same manner as plasma actuator A-1. Therefore, the overlap between the first electrode and the second electrode was 0.3 mm. An active oxygen supplying device was fabricated and evaluated in the same manner as in Example 1, except for using this plasma actuator C-1.

[0102] Example 6 Plasma actuator C-2 was fabricated in the same manner as plasma actuator B-1, except that the overlap between the first electrode and the second electrode was changed to 0.7 mm. An active oxygen supplying device was then fabricated in the same manner as in Example 1, except that this plasma actuator C-2 was used, and was subjected to evaluation.

[0103] The evaluation results are shown in Table 2. [Table 2]

[0104] As is clear from a comparison of Examples 1-2, 3-4, and 5-6, in a plasma actuator having a second electrode with a convex portion whose width in the Y-axis direction is constant, even if the overlap amount between the first and second electrodes in the X-axis direction changes, the discharge length and the amount of ozone do not change, and the change in current consumption is also small. Therefore, it is possible to provide an active oxygen supplying device with small performance errors during production. [Explanation of symbols]

[0105] 101: Active oxygen supply device (treatment device using active oxygen), 102: Ozone decomposition device (ultraviolet light source (ultraviolet lamp)), 103: Plasma actuator, 104: Object to be treated, 104-1: Treatment surface of object to be treated, 105: Induced flow, 106: Opening, 107: Housing

Claims

1. The plasma actuator includes a housing having at least one opening, and an ozone decomposition device disposed inside the housing. The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode toward the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The active oxygen supplying device is characterized in that the width of the convex portion is constant in the second direction.

2. When the cross section of the plasma actuator in the thickness direction is viewed, The first electrode and the second electrode are disposed diagonally opposite each other in the thickness direction of the plasma actuator with the dielectric interposed therebetween, the first electrode is provided to cover a portion of the first surface of the dielectric; the first surface has an exposed portion that is not covered with the first electrode; when the plasma actuator is seen through from the first electrode side, at least a portion of the exposed portion overlaps with the second electrode, 2. The active oxygen supply device according to claim 1, wherein the induced flow containing ozone is blown out from the edge of the first electrode on the first direction side in the cross section in the thickness direction along the exposed portion of the dielectric overlapping with the second electrode.

3. 3. The active oxygen supplying device according to claim 1, wherein the edge portion of the first electrode on the first direction side has a linear shape extending perpendicular to the first direction and along the first surface of the dielectric.

4. 4. The active oxygen supplying device according to claim 1, wherein the protrusions are a plurality of protrusions of substantially the same shape that are provided continuously.

5. 5. The active oxygen supplying device according to claim 1, wherein the protrusions have a periodic and regular wave shape.

6. 6. The active oxygen supplying device according to claim 1, wherein the convex portion has a rectangular wave shape.

7. The ozone decomposition device an ultraviolet light source that irradiates the induced flow containing the ozone with ultraviolet light to generate the active oxygen in the induced flow; a heating device that heats the induced flow containing the ozone to generate the active oxygen in the induced flow; and The active oxygen supply device according to any one of claims 1 to 6, which is at least one device selected from the group consisting of humidifiers that humidify the induced flow containing ozone and generate the active oxygen in the induced flow.

8. An active oxygen treatment device that treats the surface of a workpiece with active oxygen, The processing device includes a housing having at least one opening, a plasma actuator disposed inside the housing, and an ozone decomposition device; The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode toward the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The protrusion has a constant width in the second direction.

9. A treatment method for treating a surface of a workpiece with active oxygen, comprising: providing an active oxygen treatment device; The treatment device using active oxygen includes a housing having at least one opening, a plasma actuator disposed inside the housing, and an ozone decomposition device; The plasma actuator is formed by laminating a first electrode, a dielectric, and a second electrode in this order, the first electrode is an exposed electrode provided on a first surface that is one surface of the dielectric; The plasma actuator generates a dielectric barrier discharge from the first electrode toward the second electrode by applying a voltage between the first electrode and the second electrode, and blows out an induced flow containing ozone from the first electrode in a first direction that is one direction along the surface of the dielectric, the ozone decomposition device decomposes the ozone contained in the induced flow to generate active oxygen in the induced flow, and the induced flow becomes an induced flow containing the active oxygen; the plasma actuator and the ozone decomposition device are arranged so that the induced flow containing the active oxygen flows out of the housing through the opening, When the plasma actuator is seen through from the second electrode side, an edge portion of the second electrode on a second direction side opposite to the first direction is provided with a convex portion extending in the second direction, and the second electrode overlaps with the first electrode only at the convex portion; The protrusion has a constant width in the second direction, The treatment method further includes a step of placing the prepared treatment device using active oxygen and the object to be treated in relative positions such that the surface of the object to be treated is exposed when the induced flow containing the active oxygen is caused to flow out from the opening; and causing the induced flow containing the active oxygen to flow out from the opening to treat the surface of the object with the active oxygen.

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