Sterilization device, sterilization method, active oxygen supply device, and treatment device using active oxygen

Abstract

Provided are sterilization devices and the like that exhibit superior sterilization performance, superior to that achieved with ozone or ultraviolet light. The sterilization devices and the like are equipped with a plasma generator and an ultraviolet light source. The plasma generator is a plasma actuator having a first electrode and a second electrode disposed so as to sandwich a dielectric. In the plasma actuator, an induced flow including ozone is generated by applying a voltage between the two electrodes. The ultraviolet light source is arranged so as to irradiate the surface of a sterilization target, and the plasma actuator is arranged so as to supply the induced flow to the surface.

Description

Technical Field

[0001] The present invention relates to a sterilization device and a sterilization method, an active oxygen supply device, and a treatment device using active oxygen. Background Art

[0002] Ultraviolet light and ozone are known as methods for sterilizing articles and the like. Patent Document 1 discloses a method using a sterilization apparatus having an ozone supply device, an ultraviolet light generating lamp, and a stirring device. This method sterilizes even the shadowed portion of a sample by stirring active oxygen generated by irradiating ozone with ultraviolet light emitted by the ultraviolet light generating lamp, thereby resolving the problem that sterilization using ultraviolet light is limited to the portion of the sterilization object irradiated by the ultraviolet light.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 1-25865 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When the inventors of the present invention studied the sterilization performance of the sterilization method according to Patent Document 1, they found that the sterilization performance was almost the same as that of a conventional sterilization method using only ozone. This finding was unexpected, as the sterilization ability of active oxygen is said to be inherently far superior to that of ozone.

[0008] One embodiment of the present invention relates to a sterilization device and method that provide superior sterilization performance, superior to that of ozone and ultraviolet light. Another embodiment of the present invention relates to an active oxygen supply device capable of actively supplying active oxygen to a treated object. Yet another embodiment of the present invention relates to a treatment device utilizing active oxygen that can more efficiently treat the surface of a treated object using active oxygen.

[0009] Solutions for solving problems

[0010] According to at least one aspect of the present invention, there is provided a sterilization device comprising a plasma generator and an ultraviolet light source, wherein:

[0011] The plasma generator is a plasma actuator that includes a first electrode and a second electrode disposed with a dielectric sandwiched therebetween, and generates an induced flow containing ozone by applying a voltage between the two electrodes.

[0012] The ultraviolet light source is arranged to irradiate the surface of the object to be sterilized, and

[0013] The plasma actuator is arranged such that the induced flow is supplied to the surface.

[0014] In addition, according to at least one aspect of the present invention, there is provided a sterilization method comprising the following steps:

[0015] providing an induced flow containing ozone to a surface of an object to be sterilized, the induced flow being generated by applying a voltage between a first electrode and a second electrode sandwiching a dielectric; and

[0016] The induction flow containing ozone supplied to the surface of the treatment object is irradiated with ultraviolet light.

[0017] In addition, according to at least one aspect of the present invention, there is provided an active oxygen supply device, comprising a plasma generator and an ultraviolet light source, wherein:

[0018] The plasma generator is a plasma actuator that includes a first electrode and a second electrode disposed with a dielectric interposed therebetween, and generates an induced flow containing ozone by applying a voltage between the first electrode and the second electrode.

[0019] The plasma actuator is arranged so that the induced flow is supplied to the surface of the object to be processed, and

[0020] The ultraviolet light source irradiates the induced flow with ultraviolet light and generates active oxygen in the induced flow.

[0021] In addition, according to at least one aspect of the present invention, there is provided a processing device using active oxygen, comprising a plasma generator and an ultraviolet light source, wherein:

[0022] The plasma generator is a plasma actuator that includes a first electrode and a second electrode disposed with a dielectric interposed therebetween, and generates an induced flow containing ozone by applying a voltage between the first electrode and the second electrode.

[0023] The plasma actuator is arranged so that the induced flow is supplied to the surface of the object to be processed, and

[0024] The ultraviolet light source irradiates the induced flow with ultraviolet light and generates active oxygen in the induced flow.

[0025] Effects of the Invention

[0026] According to one embodiment of the present invention, a sterilization device having excellent sterilization performance that is superior to that of ozone and ultraviolet light can be obtained. In addition, according to another embodiment of the present invention, a sterilization method having excellent sterilization performance that exceeds that of sterilization methods using ozone or ultraviolet light can be obtained.

[0027] Furthermore, according to one embodiment of the present invention, it is possible to obtain an active oxygen supply device capable of more actively supplying active oxygen to a workpiece.

[0028] Furthermore, according to another embodiment of the present invention, a treatment apparatus using active oxygen can be obtained that can more efficiently treat the surface of an object using active oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram showing the structure of a sterilization device according to one embodiment of the present invention.

[0030] Figure 2 is a schematic diagram showing an example of the structure of a plasma generator.

[0031] Figure 3 is an explanatory diagram showing the overlap between the first electrode and the second electrode.

[0032] Figure 4 (a) is a schematic cross-sectional view of the sterilization device according to this example, and Figure 4 (b) is its plan view.

[0033] Figure 5 4 is a schematic cross-sectional view of a sterilization apparatus according to Comparative Example 4.

[0034] Figure 6 1 is a schematic diagram showing the structure of an active oxygen supply device according to one embodiment of the present invention, the plan view being taken from a side of a housing having an opening.

[0035] Figure 7 It is along Figure 6 A cross-sectional view taken along line AA in the active oxygen supply device shown.

[0036] Figure 8 yes Figure 6 An explanatory diagram of the active oxygen supply device shown. DETAILED DESCRIPTION

[0037] Hereinafter, specific examples for implementing the embodiments of the present invention will be described with reference to the accompanying drawings. However, the sizes, materials, shapes, and relative arrangements of the components described in the embodiments should be appropriately changed according to the structure of the component to which the present invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.

[0038] In addition, in the present invention, unless otherwise specified, the description of "XX or more and YY or "XX to YY" expressing a numerical range means that the numerical range includes the lower limit and the upper limit as endpoints. When the numerical range is stated step by step, the upper and lower limits of each numerical range can be arbitrarily combined.

[0039] In addition, the "bacteria" in the "sterilization" according to the present invention refers to microorganisms, and microorganisms include fungi, bacteria, unicellular algae, viruses and protozoa, as well as animal or plant cells (stem cells, dedifferentiated cells and differentiated cells), tissue culture, fusion 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, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Vibrio cholerae, Shigella, anthrax, Mycobacterium tuberculosis, Clostridium botulinum, tetanus and Streptococcus. In addition, examples of fungi include Trichophyton, Aspergillus and Candida.

[0040] In addition, in the following description, structures having the same function are assigned the same reference numerals in the drawings, and description thereof may be omitted.

[0041] In addition, in this specification, the active oxygen supply device of the present invention and the treatment device using active oxygen of the present invention are simply collectively referred to as "active oxygen supply device".

[0042] According to the studies of the present inventors, the reason why the sterilization capability of the sterilization apparatus according to Patent Document 1 is limited is assumed to be as follows.

[0043] Patent Document 1 describes the generation of active oxygen species (ROS) with extremely high sterilization capabilities by stimulating ozone with ultraviolet light. Here, ROS is a general term for highly reactive oxygen species, such as superoxide anion radicals (·O2-) and hydroxyl radicals (·OH). Due to their inherent high reactivity, ROS can instantly oxidize and decompose bacteria and viruses.

[0044] However, since ozone absorbs ultraviolet light well, the generation of active oxygen is believed to be limited to the vicinity of the ultraviolet light generating lamp in the sterilization device according to Patent Document 1. In other words, it is believed that ultraviolet light is insufficient to reach ozone present at a location far from the ultraviolet light generating lamp, and that almost no active oxygen is generated at a location far from the ultraviolet light generating lamp.

[0045] In addition, active oxygen is extremely unstable, among which O2 - The half-life is 10 -6 seconds and the half-life of OH is 10 -9seconds, both of which are quickly converted into stable oxygen and water. Therefore, it is difficult to fill the interior of the body of the sterilization device with the active oxygen generated near the ultraviolet light generating lamp, and unless the sterilization object is placed at a position very close to the ultraviolet light generating lamp (for example, within about 1 cm relative to the ultraviolet light generating lamp), it is considered difficult to significantly sterilize with active oxygen. In other words, in the case where the sterilization object is present at a distance of 1 cm or more relative to the ultraviolet light generating lamp, it is considered that the sterilization of the sterilization object is essentially carried out by ozone. Therefore, it is considered that the sterilization performance of the sterilization method according to Patent Document 1 is roughly the same as the sterilization performance of the conventional sterilization method using only ozone.

[0046] Based on these considerations, the inventors of the present invention have recognized that when the active oxygen with a short service life is used to treat the treated object, it is necessary to more actively place the treated object and the treated surface in an active oxygen atmosphere. As a result of the research conducted by the inventors under this understanding, it has been found that by using the sterilizing device and the active oxygen supply device of the embodiment described below, the treated object can be more actively placed in an active oxygen atmosphere. In the present invention, the "treatment" of the treated object using active oxygen includes various types of treatments that can be achieved by active oxygen, such as surface modification (hydrophilization treatment), sterilization, deodorization and bleaching of the surface of the treated object using active oxygen.

[0047] Figure 1 A sterilization device 101 according to an embodiment of the present invention is shown. The sterilization device 101 includes an ultraviolet light source 102 and a plasma generator 103 within a sterilization container 112.

[0048] The ultraviolet light source 102 is arranged so as to be able to irradiate a treatment surface 105-1 of a treatment object 105 as a sterilization target placed on a mounting table 110. Figure 1 In FIG. 1 , reference numeral 109 denotes an induced flow.

[0049] exist Figure 2 , a cross-sectional structure of an embodiment of the plasma generator 103 is shown in FIG. The plasma generator is a so-called dielectric barrier discharge (DBD) plasma actuator (hereinafter sometimes referred to as "DBD-PA"), in which a first electrode 203 is provided on one surface of a dielectric 201 (hereinafter referred to as "first surface"), and a second electrode 205 is provided on a surface opposite to the first surface (hereinafter referred to as "second surface"). Figure 2 , reference numeral 206 denotes a dielectric substrate, and reference numeral 207 denotes a power source.

[0050] In plasma generator 103, first electrode 203 and second electrode 205 are arranged so as to sandwich dielectric 201 and are arranged at an angle with an offset. By applying a voltage between these electrodes (between the two electrodes), plasma 202 is generated from first electrode 203 toward second electrode 205. Surface plasma 202 induces a jet-like flow from edge 204 of first electrode 203 along exposed portion 201-1 of the first surface of dielectric 201 (the portion not covered by the first electrode). Simultaneously, an air inlet flow is generated from the space within the container toward the electrodes. Electrons in surface plasma 202 collide with oxygen molecules in the air, causing them to dissociate and generate oxygen atoms. The generated oxygen atoms collide with undissociated oxygen molecules to generate ozone. Therefore, due to the interaction between the jet-like flow generated by surface plasma 202 and the inlet flow of air, an induced flow 109 containing a high concentration of ozone is generated from edge 204 of first electrode 203 along the surface of dielectric 201.

[0051] The plasma generator 103 is arranged on the mounting table 104 so that the induced flow 109 is supplied to the processing surface 105 - 1 of the processing object 105 irradiated with the ultraviolet light from the ultraviolet light source 102 .

[0052] That is, in a sterilization device according to one embodiment of the present invention, the induced flow 109 containing ozone from the plasma generator 103 is supplied to the processing surface 105-1 of the object to be processed 105, thereby making it possible to locally increase the ozone concentration in the area close to the processing surface 105-1 (specifically, for example, in the spatial area from the processing surface 105-1 to a height of about 1 mm (hereinafter referred to as the "surface area")). Therefore, there is no need to increase the ozone concentration in the space from the ultraviolet light source 102 to the surface area, and the ultraviolet light can be prevented from attenuating before reaching the surface area. As a result, the ozone present in the surface area is efficiently decomposed into active oxygen by the ultraviolet light. In addition, as a result, active oxygen is generated on the processing surface 105-1 of the object to be processed or at a position very close to the processing surface 105-1. As a result, the processing surface 105-1 of the object to be processed 105 is placed in an active oxygen atmosphere generated in situ on the processing surface, and the processing surface is more reliably sterilized by the active oxygen.

[0053] <Electrodes and Dielectrics>

[0054] The materials constituting the first electrode and the second electrode are not particularly limited as long as they are highly conductive materials. For example, metals (such as copper, aluminum, stainless steel, gold, silver, and platinum), materials plated or vapor-deposited with these metals, conductive carbon materials (such as carbon black, graphite, and carbon nanotubes), and composite materials that are mixtures of these with resins can be used. The material forming the first electrode and the material forming the second electrode may be the same or different.

[0055] Among them, from the viewpoint of avoiding electrode corrosion and achieving uniform discharge, the material constituting the first electrode is preferably aluminum, stainless steel or silver. For the same reason, the material constituting the second electrode is also preferably aluminum, stainless steel or silver.

[0056] Furthermore, the shape of the first electrode and the second electrode may be plate-like, linear, or needle-like, etc., without particular limitation. Preferably, the shape of the first electrode is flat. Furthermore, preferably, the shape of the second electrode is flat. In the case where at least one of the first electrode and the second electrode is flat, the flat plate preferably has an aspect ratio (long side length / short side length) of 2 or greater.

[0057] At least one of the first electrode and the second electrode preferably has a vertex angle of 45° or less (i.e., the electrode is pointed), but this feature is not limiting. Although the drawings show the case where the vertex angles of the first electrode and the second electrode are both 90°, the present invention also includes embodiments where the vertex angle exceeds 45°.

[0058] 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 that are mixtures of these with resins can be used. Among them, ceramics and glass are preferred because they can further increase the electric field strength.

[0059] <Plasma Actuator>

[0060] The plasma actuator is not particularly limited, as long as it can generate an induced flow containing ozone by providing a first electrode and a second electrode with a dielectric sandwiched therebetween and applying a voltage between these electrodes. In a plasma actuator, the shorter the shortest distance between the first and second electrodes, the easier it is to generate plasma. Therefore, the thickness of the dielectric is preferably as small as possible, as long as electrical breakdown does not occur, and can be between 10 μm and 1000 μm, preferably between 10 μm and 200 μm. Furthermore, the shortest distance between the first and second electrodes is preferably 200 μm or less.

[0061] Figure 3This is an explanatory diagram of the overlap between the first electrode 203 and the second electrode 205 of a plasma actuator serving as an ozone generator. This is a cross-sectional view of the plasma actuator.

[0062] In the first electrode 203 and the second electrode 205, which are arranged obliquely relative to each other, when viewed from the top of a cross-sectional view, the edge of the first electrode may exist in the portion where the second electrode is formed so as to sandwich the dielectric. In other words, the first and second electrodes may be arranged so as to overlap with each other so as to sandwich the dielectric. In this case, it is preferable to prevent dielectric breakdown when a voltage is applied in the portion where the first and second electrodes overlap with the dielectric.

[0063] Furthermore, when the first electrode and the second electrode are separated from each other when viewed from above in the cross-sectional view, it is preferable to increase the voltage to compensate for the weakening of the electric field due to the increased distance between the electrodes. Assuming that the overlap length is positive, the overlap between the edge of the first electrode and the edge of the second electrode when viewed from above in the cross-sectional view is more preferably -100 μm to +1000 μm.

[0064] The thickness of both the first and second electrodes is not particularly limited and can be 10 μm to 1000 μm. When the thickness is 10 μm or greater, the impedance becomes low and plasma generation is easy. When the thickness is 1000 μm or less, electric field concentration may occur, and plasma generation may be possible.

[0065] For both the first electrode and the second electrode, the width of the electrode is not particularly limited and may be 1000 μm or more.

[0066] Furthermore, when the edge of the second electrode is exposed, plasma is also generated from the edge of the second electrode, and an induced flow is generated in the opposite direction to the induced flow 109 originating from the first electrode. In the sterilization apparatus according to this embodiment, it is preferable to keep the ozone concentration in the internal space of the sterilization container other than the surface area of ​​the treated object as low as possible. Furthermore, it is preferable not to generate a gas flow in the container that interferes with the flow of the induced flow 109. Therefore, it is preferable not to generate an induced flow originating from the second electrode. Therefore, it is preferable as Figure 2 and Figure 3 As shown, the second electrode 205 is covered with a dielectric such as a dielectric substrate 206 or embedded in the dielectric 201 to prevent plasma generation from the edge of the second electrode.

[0067] The induced flow 109 containing high-concentration ozone flows in the direction of a jet-like flow induced by surface plasma from edge 204 of first electrode 203 along exposed portion 201-1 of the first surface of dielectric 201 (i.e., in the direction from edge 204 of first electrode 203 along exposed portion 201-1 of the first surface of dielectric). This induced flow is a flow of gas containing high-concentration ozone and having a velocity of several to several tens of m / s.

[0068] The voltage applied between the first electrode 203 and the second electrode 205 of the plasma actuator is not particularly limited, as long as plasma can be generated in the plasma actuator. Furthermore, the voltage may be a DC voltage or an AC voltage, but an AC voltage is preferred. Furthermore, in a preferred embodiment, the voltage is a pulsed voltage.

[0069] The voltage amplitude may be 1 kV to 100 kV. The voltage frequency is preferably 1 kHz or higher, more preferably 10 kHz to 100 kHz. When the voltage is an AC voltage, the AC voltage waveform is not particularly limited, and a sine wave, a rectangular wave, a triangular wave, or the like may be used. However, a rectangular wave is preferred from the viewpoint of rapid voltage rise.

[0070] The duty cycle of the voltage can also be appropriately selected, but it is preferred that the voltage rises quickly. Preferably, the voltage is applied so that the voltage rises from the bottom to the peak of the wavelength amplitude is 4,000,000 V / second or more.

[0071] A value 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 (voltage / film thickness) is preferably 10 kV / mm or more.

[0072] <UV Light Source and UV Light>

[0073] The ultraviolet light source is not particularly limited as long as it can emit ultraviolet light capable of exciting ozone and generating active oxygen. However, since the peak 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.

[0074] Examples of specific ultraviolet light sources that can be used include low-pressure mercury lamps (in which mercury is enclosed in quartz glass together with an inert gas such as argon or neon), cold-cathode ultraviolet lamps (UV-CCLs), and ultraviolet LEDs. The wavelengths of the low-pressure mercury lamps and cold-cathode ultraviolet lamps can be selected from 254 nm, etc. On the other hand, from the perspective of output performance, the wavelength of the ultraviolet LED can be selected from 265 nm, 275 nm, 280 nm, etc.

[0075] <Layout of Plasma Generator, UV Light Source, and Object to be Treated>

[0076] The position of the plasma generator 103 that generates the induced flow containing ozone in the sterilization container 112 is arranged so that the induced flow 109 containing ozone is supplied to the treatment surface 105-1 of the object to be sterilized to increase the ozone concentration in the surface area of ​​the object to be treated.

[0077] For example, the plasma generator and the object to be treated may be arranged so that the induced flow 109 containing high-concentration ozone is supplied to the surface of the object to be treated via the shortest distance.

[0078] Furthermore, for example, the processing surface 105 - 1 of the object to be processed may be arranged to be included on an extension line from the edge of the first electrode of the plasma exciter in a direction along the exposed portion 201 - 1 of the first surface of the dielectric.

[0079] In addition, the angle between the extended line from the edge of the first electrode of the plasma actuator along the direction of the exposed portion 201-1 of the first surface of the dielectric and the processing surface 105-1 of the object to be processed (plasma actuator incident angle, also called PA incident angle) is preferably 0° to 45°, and more preferably 0° to 30°.

[0080] By arranging the plasma generator and the object to be treated as described above, an induced flow containing ozone and having a certain flow rate can be locally supplied to a region near the surface of the object to be treated.

[0081] The ultraviolet light source is not particularly limited as long as it is arranged so as to irradiate the surface of the object to be sterilized.

[0082] As described above, since the ozone-containing induction flow is supplied to the area near the surface of the treated object, the ozone concentration near the surface can be locally increased. This prevents the ultraviolet light from the ultraviolet light source from being absorbed and attenuated by ozone before reaching the surface area. As a result, the ozone present in the surface area is efficiently decomposed into active oxygen by the ultraviolet light.

[0083] The distance between the UV light source and the object to be treated is preferably 3 cm or less, more preferably 1 cm or less. However, the object to be treated need not be placed within about 1 cm of the UV light source, and a single device can sterilize the surface of objects to be treated of various sizes and thicknesses.

[0084] In another preferred embodiment, a moving part for the UV light source and / or the object to be treated is provided so that the UV light source and / or the object to be treated can be moved to ensure uniform illumination.

[0085] Furthermore, the angle formed between the ultraviolet light emitted from the ultraviolet light source and a line extending from the edge of the first electrode of the plasma actuator along the surface of the dielectric, with the object being treated as the vertex, is preferably 45° to 180°. When this angle is 45° to 180°, the generation of active oxygen species by UV light and ozone before reaching the object being treated can be prevented, further enhancing the sterilization effect.

[0086] Furthermore, at the intersection of the line extending from the edge of the first electrode in the direction along the surface of the dielectric of the plasma exciter and the ultraviolet light emitted from the ultraviolet light source (i.e., at the position of the ultraviolet light from the ultraviolet light source corresponding to the surface of the object to be processed), the illuminance is preferably 100 μW / cm 2 In addition, an induced flow having an ozone concentration of 20 ppm or higher is preferably generated at the intersection of the ultraviolet light emitted from the ultraviolet light source and a line extending from the edge of the first electrode in the direction along the surface of the dielectric of the plasma actuator (i.e., at a position of the ultraviolet light from the ultraviolet light source corresponding to the surface of the object to be treated).

[0087] Figures 6 to 8 The structure of an active oxygen supply device 600 according to one embodiment of the present invention is shown.

[0088] Figures 6 to 8 Reference numerals 102, 103, 105, 105-1 and 109 in FIG. Figure 1 The same reference numerals are used in the drawings. Figures 6 to 8 The active oxygen supply device includes a shell 601 having at least one opening 605, and an ultraviolet light source 102 and a plasma actuator 103 are arranged inside the shell. The plasma actuator 103 is arranged so that an induced flow 109 containing ozone from the plasma actuator flows out of the shell through the opening 605. The ultraviolet light source 102 is arranged so that the induced flow 109 is irradiated with ultraviolet light emitted from the ultraviolet light source. In the induced flow irradiated with ultraviolet light, the ozone in the induced flow is excited and contains active oxygen. As a result, the induced flow including active oxygen flows out from the opening. At this time, by arranging the object to be treated 105 to be in contact with the opening, active oxygen is actively supplied to the surface to be treated 105-1, and the surface to be treated can be actively placed in an active oxygen atmosphere. In addition, by arranging the object to be treated 105 near the opening, the induced flow flowing out of the opening flows along the surface of the object to be treated (see Figure 7 (See reference numeral 109-1 in the figure). Portions of the treated surface other than the portion facing the opening are also exposed to the induced flow containing active oxygen. Therefore, a wider area of ​​the treated surface 105-1 can be treated with active oxygen. The above description relates to the plasma actuator according to this embodiment, the electrodes and dielectric used in the plasma actuator, and the ultraviolet light source and ultraviolet light.

[0089] Here, the intensity of the ultraviolet light source and its position relative to the plasma generator can be set so that the induced flow is irradiated with light containing ultraviolet light to generate reactive oxygen species in the induced flow, and the induced flow containing an effective amount of reactive oxygen species corresponding to the purpose of the treatment can be supplied to the object to be treated through the opening. As an example of the arrangement position of the ultraviolet light source relative to the plasma actuator, for example, the distance from the surface of the dielectric of the plasma actuator facing the ultraviolet light source is preferably 10 mm or less, and particularly 4 mm or less. As an example of the intensity of the light containing ultraviolet light, for example, the illuminance on the surface of the dielectric of the plasma actuator facing the ultraviolet light source is preferably 40 μW / cm 2 or greater, especially 100 μW / cm 2 Although the upper limit of the illuminance is not particularly limited, it is preferably 10000 μW / cm 2 or smaller.

[0090] Furthermore, regarding the distance between the plasma actuator and the opening, it is preferable that the distance between the plasma actuator and the object to be treated be short to more effectively utilize the reactive oxygen species in the induced flow for the desired treatment. Therefore, it is preferable to place the plasma actuator closer to the opening. Furthermore, to protect the plasma actuator, it is also preferable to place the plasma actuator rearward from the opening. For example, the plasma actuator is preferably placed on the inner wall of the housing such that the end of the plasma actuator on the side 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.

[0091] In addition, in the active oxygen supply device according to this embodiment, there is no particular restriction on the positions of the plasma generator 103 and the ultraviolet light source 102 that generate the induced flow including ozone, as long as active oxygen is generated in the induced flow by light including ultraviolet light from the ultraviolet light source, and the induced flow including an effective amount of active oxygen corresponding to the purpose of the treatment flows out from the opening and is supplied to the treated surface.

[0092] In this embodiment, the flow rate of the induced flow from the opening is not particularly limited, as long as an induced flow containing an effective amount of active oxygen is supplied to the treated surface based on the distance of the treated object from the opening and the purpose of the treatment. For example, if, as described above, the plasma actuator is arranged within the housing so that the end of the plasma actuator near the opening is located 0.5 mm to 1.5 mm from the edge of the opening on the inner wall of the housing, and the treated surface of the treated object is positioned relative to the treated object so that the distance from the surface of the housing having the opening is 0.5 mm to 2 mm, the preferred flow rate of the induced flow in the opening is 0.01 m / s to 100 m / s. This flow rate can be adjusted by the dielectric material and the voltage conditions applied to the electrodes of the plasma actuator. With respect to the dielectric, the higher the volume resistivity, the stronger the electric field strength, resulting in a higher velocity of the induced flow from the plasma actuator. Therefore, as described above, it is more preferable to use a ceramic such as glass as the dielectric. Furthermore, the preferred voltage conditions are as described above.

[0093] In accordance with Figures 6 to 8 In the active oxygen supply device of the embodiment, the housing is configured so that the ultraviolet light does not directly irradiate the treated surface. However, the configuration in which the ultraviolet light directly irradiates the treated surface is classified as a modification of this embodiment. In this case, since the active oxygen can also be generated in situ on the treated surface, it is expected that the treatment efficiency of the treated surface will be further improved.

[0094] Here, in sterilization using only ultraviolet light, only the surface irradiated with ultraviolet light is sterilized. However, in sterilization using the active oxygen supply device according to the present invention, bacteria present in locations where active oxygen can reach can be sterilized. Therefore, for example, even bacteria present between fibers, which are difficult to sterilize with external ultraviolet light, can be sterilized.

[0095] Example

[0096] The present invention will be described in more detail below using examples and comparative examples, but the embodiments of the present invention are not limited thereto.

[0097] <Example 1>

[0098] 1. Preparation of Sterilization Device

[0099] A first electrode was formed by attaching an aluminum foil measuring 18 mm in length, 9.5 mm in width, and 100 μm in thickness to the first side of a glass plate (18 mm in length, 18 mm in width, and 150 μm in thickness) serving as a dielectric, using pressure-sensitive adhesive tape, leaving an area of ​​18 mm in length and 3 mm in width exposed on the first side of the glass plate. Furthermore, a second electrode was formed by attaching an aluminum foil measuring 18 mm in length, 9 mm in width, and 100 μm in thickness to the second side of the glass plate, using pressure-sensitive adhesive tape, so that it obliquely faces the aluminum foil attached to the first side. Furthermore, the second side including the second electrode was covered with polyimide tape. In this manner, a plasmon actuator was fabricated in which the first and second electrodes were arranged so as to overlap each other over a width of 0.5 mm, sandwiching the dielectric (glass plate).

[0100] like Figure 4 As shown, the plasma actuator is placed on a mounting table 403 in a sterilization container 112 having a length of 15 cm, a width of 10 cm and a height of 7 cm, so that the first electrode faces vertically upward, and the surface (201-1) of the glass plate on which the first electrode is formed and not covered by the first electrode is horizontal. Figure 4 (a) is a schematic cross-sectional view of the sterilization apparatus according to this example, and Figure 4 (b) is a plan view.

[0101] In addition, the placement table 110 for the sterilized object is arranged inside the sterilization device. The placement table 110 is arranged at the following position: the distance between the end of the first electrode and the center of the object to be treated is ( Figure 4 The LPA in (a) is 5 cm, and the processed surface of the evaluation sample described below is horizontal and flush with the surface of the dielectric of the plasma actuator 103 on which the first electrode is formed and not covered by the first electrode.

[0102] In addition, a cold cathode tube ultraviolet lamp (trade name: UW / 9F89 / 9, manufactured by Stanley Electric Co., Ltd., peak wavelength = 254nm) was prepared as an ultraviolet light source. The lamp was placed at the following positions in the sterilization container: between the treated surface and the cold cathode tube ultraviolet lamp ( Figure 4 The distance between the LUVs in (a) is 3 cm, and the incident angle of the UV light toward the center of the treated surface is ( Figure 4 θUV) in (a) is 90°.

[0103] For this sterilization device, an illuminometer (trade name: Spectral irradiance meter USR-45D, manufactured by Ushio Inc.) was placed at the position of the treated surface when the evaluation sample was placed on the mounting table, and the illuminance of ultraviolet light was measured. The integrated value of the spectrum was 487 μW / cm 2 .

[0104] Five minutes after applying a sinusoidal voltage with an amplitude of 2.4 kV and a frequency of 80 kHz to the plasma actuator, 50 ml of gas was sampled from the position of the treated surface when the evaluation sample was placed on the mounting table. The sampled gas was drawn into an ozone detection tube (trade name: 182SB, manufactured by Komyo Rikagaku Kogyo KK), and the ozone concentration contained in the induced flow from the plasma actuator was measured to be 40 ppm (reading value × 2). Furthermore, 50 ml of gas was sampled at the midpoint (LUV / 2) between the treated surface and the ultraviolet light source, and the sampled gas was drawn into an ozone detection tube (trade name: 182SB, manufactured by Komyo Rikagaku Kogyo KK). The ozone concentration was measured to be 8 ppm (reading value × 2).

[0105] 2. Preparation of samples for evaluation

[0106] A stamp medium (trade name: PETAN CHECK 25PT1025, manufactured by Eiken Chemical Co., Ltd.) was placed at 25 g / cm 2 A door handle that had not been wiped with water, alcohol, etc. within a week in a place where an unspecified number of people entered and exited was pressed with a pressure of 10 seconds, and then the seal culture medium was allowed to stand in an environment with a temperature of 37°C for 12 hours. The colonies grown in the seal culture medium were collected using a sterile cotton swab and dispersed in distilled water to prepare a bacterial solution. A new seal culture medium (PETAN CHECK 25PT1025 manufactured by Eiken Chemical Co., Ltd.) was smeared with 0.1 ml of the diluted bacterial solution obtained by diluting the bacterial solution 10 times with distilled water, and allowed to stand in an environment of 37°C for 12 hours. As a result, the growth of 200 CFU / ml to 300 CFU / ml of bacteria was confirmed.

[0107] Therefore, a sample for evaluation was prepared by applying 0.1 ml of the diluted bacterial solution on a new stamp medium (PETAN CHECK 25PT1025 manufactured by Eiken Chemical Co., Ltd.).

[0108] 3. Sterilization test

[0109] The evaluation sample 401 prepared in point 2 above was placed on the mounting table 110 of the sterilization apparatus produced in point 1 above. Next, a voltage having a sinusoidal waveform with an amplitude of 2.4 kV and a frequency of 80 kHz was applied to the plasma actuator, and sterilization was performed by irradiating the sample with ultraviolet light for 5 minutes. Thereafter, the evaluation sample was removed from the sterilization apparatus and incubated at a temperature of 37°C for 12 hours. The number of viable bacteria was calculated based on the number of colonies grown on the culture medium. This sterilization test was performed three times, and the average value was multiplied by 10 to serve as the number of colonies in the sterilization test according to this embodiment. Based on the obtained number of colonies, the sterilization performance was evaluated according to the following criteria (Ten Cate judgment display method).

[0110] -: No growth

[0111] ±: colony count <10

[0112] +: colony count 10 to 29

[0113] ++: colony count 30 to 100

[0114] +++: colony count > 100

[0115] ++++: Countless colonies

[0116] <Examples 2 to 5>

[0117] A sterilization device was produced and evaluated in the same manner as in Example 1, except that the ultraviolet light source and the thickness of the dielectric of the plasma actuator were changed as shown in Table 1. In Example 2, an ultraviolet LED (peak wavelength: 280 nm) was used as the ultraviolet light source.

[0118] <Comparative Examples 1 to 3>

[0119] The conditions of Comparative Examples 1 to 3 were the same as those of Example 1 except that the following changes were made.

[0120] Comparative Example 1: No voltage was applied to the plasma actuator, and no ultraviolet light irradiation was performed.

[0121] Comparative Example 2: UV light irradiation was performed for 5 minutes without applying voltage to the plasma actuator.

[0122] Comparative Example 3: A voltage was applied to the plasma actuator for 5 minutes without ultraviolet light irradiation.

[0123] <Comparative Example 4>

[0124] In the sterilization device of Example 1, the plasma actuator is arranged so that: Figure 5The induced flows are shown to flow on opposite sides of the object being treated, the distance between the edge of the first electrode and the center of the object being treated is 10 cm, and the distance between the ultraviolet light source and the surface of the object being treated is 3 cm.

[0125] Then, voltage was applied to the plasma actuator under the same conditions as in Example 1, and the interior of the sterilization container was filled with ozone, achieving an ozone concentration of 40 ppm in the surface area of ​​the treated surface. The evaluation sample was then moved from the preparatory chamber into the sterilization chamber and placed on the stage, ensuring that the ozone concentration in the sterilization container did not decrease. Subsequently, the evaluation sample was irradiated with ultraviolet light from a UV light source for 5 minutes to sterilize it, in the same manner as in Example 1. Subsequent operations were performed in the same manner as in Example 1, and the number of developed colonies was counted and evaluated.

[0126] [Table 1]

[0127] Table 1

[0128]

[0129] In the table, PA stands for plasma actuator, and UV stands for ultraviolet light.

[0130] <Example 6>

[0131] 1. Fabrication of treatment equipment using active oxygen and evaluation of its characteristics

[0132] First, prepare Figure 7 The housing 601 of the active oxygen supply device 600 is shown. Figure 6 It is viewed from the side of the housing 601 having the opening 605 Figure 7 The size of the housing when placed with the opening 605 facing vertically downward is 20 mm in height, 150 mm in depth and 20 mm in width. The width of the opening 605 is 7 mm and its length is 15 mm. Figure 6 As shown, the opening 605 is provided so that the longitudinal direction thereof coincides with the depth direction of the housing.

[0133] Furthermore, the plasma actuator 103 was manufactured in the same manner as in Example 1. Then, as Figure 7 As shown, the plasma actuator 103 is fixed to the inner wall of the housing 601. Specifically, one end of the first electrode 203 of the plasma actuator 103 is horizontally aligned with the center of the ultraviolet light source 102 and is fixed so that the induced flow 109 from the plasma actuator 103 flows out from the opening 605. Here, the distance between the surface of the plasma actuator 103 facing the ultraviolet light source and the ultraviolet light source 102 ( Figure 8The reference numeral 607 in FIG. 1 is set to 2 mm, and the distance ( ) between the lower end of the plasma actuator 103 and the lower end of the opening 605 (outside of the housing) is set to 2 mm. Figure 8 As the ultraviolet light source 102, a cold cathode ultraviolet lamp (trade name: UW / 9F89 / 9, manufactured by Stanley Electric Co., Ltd., peak wavelength = 254 nm) was used in the same manner as in Example 1.

[0134] For the active oxygen supply device 600 thus obtained, an illuminometer (trade name: Spectroradiometer USR-45D, manufactured by Ushio Inc.) was placed on the surface of the glass plate 201 of the plasma actuator 103 facing the ultraviolet lamp, and the illuminance of the ultraviolet light was measured. Based on the integrated value of the spectrum, the illuminance was 1370 μW / cm 2 Furthermore, the illuminance of ultraviolet light when the illuminometer is placed in contact with the opening 605 is 0.3 μW / cm 2 Thus, it was confirmed that substantially no ultraviolet light leaked from the opening.

[0135] Next, without turning on the power to the UV lamp to prevent the UV light from affecting ozone decomposition, a sinusoidal voltage with an amplitude of 2.4 kV and a frequency of 80 kHz was applied between the two electrodes of the plasma actuator 103. After five minutes, 50 ml of the induced flow flowing out of the opening was sampled. The sampled gas was drawn into an ozone detection tube (trade name: 182SB, manufactured by Komyo Rikagaku Kogyo KK), and the ozone concentration contained in the induced flow from the plasma actuator was measured to be 70 ppm (reading value × 2).

[0136] Next, a voltage having a sinusoidal waveform with an amplitude of 2.4 kV and a frequency of 80 kHz was applied between the two electrodes of the plasma actuator, and the ultraviolet lamp was turned on so that the illuminance on the surface of the glass plate 201 of the plasma actuator 103 facing the ultraviolet lamp was 1370 μW / cm 2 Then, the ozone concentration in the induced flow flowing out of the opening at this time was measured in the same manner as above. The result was 18 ppm. Based on these results, it is believed that the induced flow includes active oxygen generated by decomposing 52 ppm of ozone with ultraviolet light.

[0137] 2-1. Treatment (sterilization) test

[0138] (1) Preparation of samples for sterilization test

[0139] Three evaluation samples prepared for the sterilization performance verification test in Example 1 were prepared.

[0140] As in Example 1, a stamp medium (trade name: PETAN CHECK 25PT1025, manufactured by Eiken Chemical Co., Ltd.) was placed at 25 g / cm 2 A door handle that had not been wiped with water, alcohol, etc. within a week in a place where an unspecified number of people entered and exited was pressed with a pressure of 10 seconds, and then the stamp culture medium was allowed to stand for 12 hours in an environment with a temperature of 37°C. Bacterial colonies grown in the stamp culture medium were collected using sterile cotton swabs and dispersed in distilled water to prepare a bacterial solution. A new stamp culture medium (PETAN CHECK 25PT1025 manufactured by Eiken Chemical Co., Ltd.) was smeared with 0.1ml of the diluted bacterial solution obtained by diluting the bacterial solution 10 times with distilled water, and allowed to stand for 12 hours in an environment of 37°C. As a result, the growth of bacteria of 200CFU / ml to 300CFU / ml was observed. Then, 0.1ml of the diluted bacterial solution was smeared on the entire surface of a glass plate (15mm long, 15mm wide, 2mm thick) that had been cleaned with 70% alcohol. Afterwards, the glass plate was placed in an environment with a temperature of 37°C for 1 hour to remove moisture. Therefore, a total of three samples for sterilization testing were prepared.

[0141] (2) Sterilization test

[0142] The active oxygen supply device was placed on the treated surface of each sample so that the distance between the surface with the opening (outer surface) of the housing and the treated surface was ( Figure 8 At this time, the width direction of the sample ( Figure 8 The center position in the left-right direction of the sample is aligned with the center position in the width direction of the opening, and is also aligned with the depth direction of the sample ( Figure 8 The center position of the glass plate 201 in the depth direction of the paper (in the depth direction of the paper) was aligned with the center position of the opening in the longitudinal direction. Next, a sinusoidal voltage with an amplitude of 2.4 kV and a frequency of 80 kHz was applied to the plasma actuator, and the ultraviolet lamp was turned on so that the illuminance on the surface of the glass plate 201 of the plasma actuator 103 facing the ultraviolet lamp was 1370 μW / cm 2 , irradiate the induced flow with ultraviolet light for 30 seconds, so that the induced flow containing active oxygen flows out from the opening and supplies the active oxygen to the treated surface (treatment time: 30 seconds).

[0143] Next, a stamp medium (trade name: PETAN CHECK 25PT1025, manufactured by Eiken Chemical Co., Ltd.) was placed at 25 g / cm 2The treated surface of the sample was pressed with a pressure of 10 seconds, and then the stamp culture medium was allowed to stand in an environment with a temperature of 37°C for 12 hours. The number of viable bacteria was calculated based on the number of colonies grown on the culture medium. The average value of the number of viable bacteria obtained from each sample was multiplied by 10 and used as the number of colonies in the sterilization test according to this example. Based on the obtained number of colonies, the sterilization performance was evaluated according to the following standard (Ten Cate judgment display method).

[0144] -: No growth

[0145] ±: colony count <10

[0146] +: colony count 10 to 29

[0147] ++: colony count 30 to 100

[0148] +++: colony count > 100

[0149] ++++: Countless colonies

[0150] 2-2. Treatment (bleaching) test

[0151] (1) Preparation of samples for bleaching test

[0152] Pepper sauce (trade name: PEPPER SAUCE, manufactured by Tabasco Co.) was filtered through a long-fiber nonwoven fabric (trade name: BEMCOT M-3II, manufactured by Asahi Kasei Corporation) to remove solids. A paper wipe (trade name: KIMWIPE S-200, manufactured by Nippon Paper Crecia Co., Ltd.) was immersed in the resulting liquid for 10 minutes. The paper wipe was then removed and rinsed with water. The rinse was repeated until the cleaning liquid no longer visually discolored. The wipe was then dried. Three samples, 15 mm in length and 15 mm in width, were then cut from the red pepper sauce-dyed paper wipe.

[0153] (2) Bleaching test

[0154] The active oxygen supply device was placed on each sample so that the distance between the surface with the opening (outer surface) of the housing and the surface to be treated ( Figure 8 At this time, the width direction of the sample ( Figure 8 The center position in the left-right direction of the sample is aligned with the center position in the width direction of the opening, and is also aligned with the depth direction of the sample ( Figure 8The center position of the glass plate 201 in the depth direction of the paper is aligned with the center position of the opening in the longitudinal direction. Next, a sinusoidal voltage with an amplitude of 2.4 kV and a frequency of 80 kHz is applied to the plasma actuator, and the ultraviolet lamp is turned on so that the illuminance on the surface of the glass plate 201 of the plasma actuator 103 facing the ultraviolet lamp is 1370 μW / cm 2 The induced flow was irradiated with ultraviolet light for 20 minutes, and the induced flow containing active oxygen was supplied to a portion of the treated surface (treatment time: 20 minutes). Next, the active oxygen supply device was removed from the treated surface, and the degree of discoloration was visually observed compared to the sample before treatment and evaluated according to the following criteria.

[0155] A: Completely bleached.

[0156] B: There is very little red color left in the chili sauce.

[0157] C: Some red color of the chili sauce remains.

[0158] D: There is no difference in color from the portion not supplied with active oxygen.

[0159] 2-3. Treatment (deodorization) test

[0160] (1) Preparation of samples for deodorization test

[0161] A paper wipe (KIMWIPE S-200, manufactured by Nippon Paper Crecia Co., Ltd.) was immersed in a fabric mist (trade name: Fabric Mist-Linen, manufactured by SABON Co.) for 10 minutes, then removed and allowed to dry naturally for 6 hours. Three samples having a length of 15 mm and a width of 15 mm were then cut out from the paper wipe.

[0162] (2) Deodorization test

[0163] The active oxygen treatment device was placed on the treated surface of each sample so that the distance between the surface with the opening (outer surface) of the housing and the treated surface was ( Figure 8 At this time, the width direction of the sample ( Figure 8 The center position in the left-right direction of the sample is aligned with the center position in the width direction of the opening, and is also aligned with the depth direction of the sample ( Figure 8 The center position of the glass plate 201 in the depth direction of the paper (in the depth direction of the paper) was aligned with the center position of the opening in the longitudinal direction. Next, a sinusoidal voltage with an amplitude of 2.4 kV and a frequency of 80 kHz was applied to the plasma actuator, and the ultraviolet lamp was turned on so that the illuminance on the surface of the glass plate 201 of the plasma actuator 103 facing the ultraviolet lamp was 1370 μW / cm 2The induced flow was irradiated with ultraviolet light for 20 seconds, and the induced flow containing active oxygen was supplied to a portion of the treated surface (treatment time: 20 seconds). The active oxygen supply device was then removed from the treated surface, and the remaining odor in the treated sample was evaluated based on the following intensity criteria, compared to the sample before treatment with active oxygen. The evaluation was conducted by five subjects, using an intensity criteria selected by at least three subjects.

[0164] A: Odorless.

[0165] B: Almost undetectable odor (detection threshold).

[0166] C: Weak odor that can be recognized as the odor of fabric mist (perception threshold).

[0167] D: No difference from the untreated sample.

[0168] <Comparative Examples 5 to 7>

[0169] The conditions of Comparative Examples 5 to 7 were the same as those of Example 6, except for the following features.

[0170] Comparative Example 5: No voltage was applied to the plasma actuator, and no ultraviolet irradiation was performed.

[0171] Comparative Example 6: Ultraviolet irradiation was performed for 2 minutes without applying voltage to the plasma actuator.

[0172] Comparative Example 7: Voltage was applied to the plasma actuator for 2 minutes without ultraviolet irradiation.

[0173] [Table 2]

[0174] Table 2

[0175]

[0176] 2-4. Treatment (Sterilization of Escherichia coli) Test

[0177] (1) Using the active oxygen supply device used in Example 6, an E. coli sterilization test was performed according to the following procedure. All instruments used in this sterilization test were sterilized with high-pressure steam using an autoclave. In addition, this sterilization test was performed in a clean bench.

[0178] First, Escherichia coli (trade name "KWIK-STIK (Escherichia coli ATCC8739)", manufactured by Microbiologics) was placed in an Erlenmeyer flask containing LB medium (distilled water was added to 2 g of tryptone, 1 g of yeast extract, and 1 g of sodium chloride to prepare 200 ml) and cultured at 37°C with shaking at 80 rpm for 48 hours. The Escherichia coli suspension after culture was 9.2 × 10 9 (CFU / ml).

[0179] Using a micropipette, 0.010 ml of the cultured bacterial suspension was dropped onto a 3 cm long, 1 cm wide, and 1 mm thick glass slide (Matsunami glass, model: S2441). The bacterial suspension was then applied to the entire surface of one side of the slide using the tip of the micropipette to prepare Sample No. 6-1. Samples No. 6-2 and No. 6-3 were prepared in a similar manner.

[0180] Next, sample No. 6-1 was immersed in a test tube containing 10 ml of a buffer solution (trade name "Gibco PBS," Thermo Fisher Scientific Inc.) for 1 hour. To prevent the bacterial suspension on the slide from drying out, the time from dropping the bacterial suspension onto the slide to immersing it in the buffer solution was set to 60 seconds.

[0181] Next, 1 ml of the buffer solution (hereinafter referred to as "1 / 1 solution") in which Sample No. 6-1 was immersed was placed in a test tube containing 9 ml of the buffer solution to prepare a dilution solution (hereinafter referred to as "1 / 10 dilution solution"). The 1 / 100 dilution solution, 1 / 1000 dilution solution, and 1 / 10000 dilution solution were prepared in the same manner, except that the dilution ratio using the buffer solution was changed.

[0182] Next, 0.050 ml of the 1 / 1 solution was sampled and applied to a stamp culture medium (PETAN CHECK 25, PT1025, manufactured by Eiken Chemical Co., Ltd.). This procedure was repeated to prepare two stamp cultures coated with the 1 / 1 solution. The two stamp cultures were placed in an incubator (trade name: IS600, manufactured by Yamato Scientific Co., Ltd.) and incubated at 37°C for 24 hours. The number of colonies produced on the two stamp cultures was counted, and the average value was calculated.

[0183] For the 1 / 10 dilution, 1 / 100 dilution, 1 / 1000 dilution, and 1 / 10000 dilution, two smeared stamp cultures were prepared and incubated in the same manner as described above for each dilution. The number of colonies produced in each stamp culture for each dilution was then counted, and the average value was calculated. Table 3 shows the results.

[0184] [Table 3]

[0185] Table 3

[0186]

[0187] From the results shown in Table 3 above, it was found that the number of colonies when the 1 / 10000 dilution was cultured was 21. Therefore, the number of bacteria present in 0.050 ml of the 1 / 1 solution related to sample No. 6-1 was 21×10 4 =210000 (CFU).

[0188] Next, the following operations were performed on Samples No. 6-2 and No. 6-3.

[0189] A recess measuring 3.5 cm in length, 1.5 cm in width, and 2 mm in depth was placed in the center of a 30 cm long, 30 cm wide, and 5 mm thick plastic plate. Glass slides were placed into the recess so that the surface of each sample glass slide opposite the side coated with the bacterial solution came into contact with the bottom of the recess. An active oxygen supply device was then placed on the top surface of the plastic plate, with the longitudinal center of the active oxygen supply device opening aligned with the longitudinal center of the recess, and the width center of the active oxygen supply device opening aligned with the transverse center of the recess. Because the recess was 2 mm deep and the glass slide was 1 mm thick, the surface of each sample with the bacterial solution adhered to it did not come into direct contact with the opening of the active oxygen supply device.

[0190] Next, the active oxygen supply device was activated, and the surface of the slide coated with the bacterial solution was treated with an induction flow containing active oxygen. The treatment time was 2 seconds for sample No. 6-2 and 10 seconds for sample No. 6-3. Furthermore, the time from dropping the bacterial solution onto the slide to immersing it in the buffer solution was set to 60 seconds to prevent the bacterial solution on the slide from drying out during treatment with the active oxygen supply device.

[0191] Treated samples No. 6-2 and No. 6-3 were immersed in a test tube containing 10 ml of a buffer solution (trade name "Gibco PBS," Thermo Fisher Scientific Inc.) for 1 hour. Next, 1 ml of the buffer solution (hereinafter referred to as "1 / 1 solution") in which each sample had been immersed was placed in a test tube containing 9 ml of the buffer solution to prepare a dilution solution (1 / 10 dilution solution). A 1 / 100 dilution solution, a 1 / 1000 dilution solution, and a 1 / 10000 dilution solution were prepared in the same manner, except that the dilution ratio of the buffer solution was changed.

[0192] Next, 0.050 ml of the 1 / 1 solution of each sample was sampled and applied to a stamp culture medium (PETAN CHECK 25, PT1025, manufactured by Eiken Chemical Co., Ltd.). This procedure was repeated to prepare two stamp cultures, each coated with 1 / 1 solution for each sample. A total of four stamp cultures were placed in an incubator (trade name: IS600, manufactured by Yamato Scientific Co., Ltd.) and incubated at 37°C for 24 hours. The number of colonies produced on the two stamp cultures was counted, and the average value was calculated.

[0193] For each sample, two smeared stamp cultures were prepared and incubated in the same manner as described above for each dilution: 1 / 10, 1 / 100, 1 / 1000, and 1 / 10000. The number of colonies produced by each dilution in each stamp culture was counted, and the average value was calculated. Table 4 shows the results.

[0194] [Table 4]

[0195] Table 4

[0196]

[0197] From the colony count in the 1 / 1000 dilution of sample No. 6-2 after treatment, it was found that the number of bacteria in 0.050 ml of the 1 / 1 solution of sample No. 6-2 was 5×10 3 = 5000 (CFU) Therefore, in this example, the sterilization rate of Escherichia coli when the treatment time is 2 seconds is 97.6% (= (210000-5000) / 210000×100).

[0198] Furthermore, from the colony count in 1 / 1 of the solution related to sample No. 6-3 after treatment, it was found that the bacterial count in 0.050 ml of the 1 / 1 solution related to sample No. 6-3 was 0 (CFU). Therefore, in this example, the sterilization rate of Escherichia coli with a treatment time of 10 seconds was 99.999% (= (210000-1) / 210000×100) or higher.

[0199] (2) Samples No. C6-1 and C6-2 were prepared in the same manner as sample No. 6-1. These samples were treated in the same manner as in (1) above, except that the ultraviolet lamp of the active oxygen supply device was not turned on. Therefore, samples No. C6-1 and No. C6-2 were treated with ozone in the induced flow. The treatment time was 2 seconds for sample No. C6-1 and 10 seconds for sample No. C6-2. For samples No. C6-1 and No. C6-2, immersion and dilution in a buffer solution were performed in the same manner as for sample No. 6-1 in (1) above. Next, in the same manner as for sample No. 6-1 in (1) above, two smeared stamp cultures were prepared and cultured for each of the 1 / 1 solution, 1 / 10 dilution, 1 / 100 dilution, 1 / 1000 dilution and 1 / 10000 dilution associated with each of sample No. C6-1 and sample No. C6-2. Then, the number of colonies produced in each stamp culture medium related to the 1 / 1 solution and each dilution of each sample was counted, and the average value was calculated. Table 5 shows the results.

[0200] [Table 5]

[0201] Table 5

[0202]

[0203] In the above results, the number of bacteria present in 0.050 ml of a 1 / 10000 dilution of the treated sample No. C6-1 was 19×10 4 = 190,000 (CFU) Therefore, in the test example using sample No. C6-1, the sterilization rate of Escherichia coli was 9.5% (= (210,000 - 190,000) / 210,000 x 100).

[0204] The results of culturing a 1 / 10000 dilution of sample No. C6-2 revealed that the number of bacteria present in 0.050 ml of the 1 / 1 dilution of sample No. C6-2 was 8×10 4= 80,000 (CFU) Therefore, in the test example using sample No. C6-2, the sterilization rate of Escherichia coli is 61.9% (= (210,000 - 80,000) / 210,000 x 100).

[0205] From the above results, it was confirmed that the treatment using active oxygen can eliminate Escherichia coli more reliably in a shorter time than the treatment using ozone alone.

[0206] (3) The slide glass used in the preparation of Sample No. 6-1 was replaced with a qualitative filter paper (product number: No. 5C, manufactured by Advantec Co., Ltd.) with a length of 3 cm and a width of 1 cm. The bacterial liquid was dripped onto only one side of the filter paper. Samples No. 7-1 and No. 7-2 were prepared in the same manner as Sample No. 6-1 except for this.

[0207] Next, the following operations were performed on Sample No. 7-1.

[0208] A recess measuring 3.5 cm long, 1.5 cm wide, and 2 mm deep was placed in the center of a 30 cm long, 30 cm wide, and 5 mm thick plastic plate. A 3.5 cm long, 1.5 cm wide piece of filter paper was placed in the recess. Sample No. 7-1 was placed on the filter paper, with the surface where the bacterial solution was dripping facing 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, with the longitudinal center of the opening of the active oxygen supply device aligned with the longitudinal center of the recess, and the width center of the opening of the active oxygen supply device aligned with the transverse center of the recess. Because the recess was 2 mm deep and the filter paper was 1 mm or less thick, the surface of each sample with the bacterial solution adhered to it did not come into direct contact with the opening of the active oxygen supply device. Next, the active oxygen supply device was activated, and the surface of the filter paper where the bacterial solution was dripping was treated with an induction flow containing active oxygen. The treatment lasted for 10 seconds. In addition, the time from dropping the bacterial solution onto the filter paper to immersing it in the buffer solution was set to 60 seconds so that the filter paper with the bacterial solution dropped thereon would not dry out during the treatment using the active oxygen supply device.

[0209] Treated sample No. 7-1 was immersed in a test tube containing 10 ml of a buffer solution (trade name "Gibco PBS," ThermoFisher Scientific Inc.) for 1 hour. Next, 1 ml of the buffer solution after immersion (hereinafter referred to as the "1 / 1 solution") was placed in a test tube containing 9 ml of the buffer solution to prepare a dilution solution (1 / 10 dilution solution). A 1 / 100 dilution solution, a 1 / 1000 dilution solution, and a 1 / 10000 dilution solution were prepared in the same manner, except that the dilution ratio of the buffer solution was changed.

[0210] Next, 0.050 ml of the 1 / 1 solution was sampled and applied to a stamp culture medium (PETAN CHECK 25, PT1025, manufactured by Eiken Chemical Co., Ltd.). This procedure was repeated to prepare two stamp cultures coated with the 1 / 1 solution. A total of two stamp cultures were placed in an incubator (trade name: IS600, manufactured by Yamato Scientific Co., Ltd.) and incubated at 37°C for 24 hours. The number of colonies produced on each stamp culture medium associated with the 1 / 1 solution of Sample No. 7-1 was counted, and the average value was calculated.

[0211] For the 1 / 10 dilution, 1 / 100 dilution, 1 / 1000 dilution, and 1 / 10000 dilution, two smeared stamps were prepared and incubated in the same manner as above for each dilution. The number of colonies produced in each stamp was counted for each dilution, and the average value was calculated.

[0212] In addition, as a control sample, 1 / 1 solution and 1 / 10 to 1 / 10000 dilutions were prepared in the same manner as for the untreated sample No. 7-2, and stamp culture medium was prepared and cultured in the same manner, and the average number of colonies was calculated. Table 6 shows the results.

[0213] Table 6

[0214]

[0215] From the results of the culture of the 1 / 1000 dilution of sample No.7-2, it was found that the number of bacteria present in 0.050 ml of the 1 / 1 dilution of sample No.7-2 was 5×10 3 = 5000 (CFU). Furthermore, the bacterial count in 0.050 ml of 1 / 1 solution of sample No. 7-1 after treatment was 0 (CFU). This indicates that the sterilization rate of E. coli in the test using sample No. 7-1 was 99.98% ((5000 - 1 / 5000) × 100) or higher.

[0216] Here, sample No. 7-1 was treated with active oxygen on the surface of the filter paper opposite to the surface where the bacterial solution was applied. This demonstrates that the sterilization treatment according to the present invention, which actively supplies active oxygen to the treated object, can sterilize not only E. coli present on the surface of the filter paper, but also within the filter paper. In this respect, the method according to the present invention is superior to sterilization treatment using only UV light, which sterilizes only the surface irradiated with UV light.

[0217] The present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are added to disclose the scope of the present invention.

[0218] This application claims priority based on Japanese Patent Application No. 2020-113518 filed on June 30, 2020, Japanese Patent Application No. 2020-176945 filed on October 21, 2020, Japanese Patent Application No. 2021-074162 filed on April 26, 2021, and Japanese Patent Application No. 2021-095018 filed on June 7, 2021, the entire contents of which are incorporated herein.

[0219] Description of Reference Numerals

[0220] 101 Sterilization Device

[0221] 102 UV light source

[0222] 103 Plasma Generator (Plasma Actuator)

[0223] 104 loading platform

[0224] 105 Objects to be processed

[0225] 105-1 Treatment surface of the treated object

[0226] 109 Induced Flow

[0227] 110 loading platform

[0228] 112 Sterilization Container

Claims

1. A sterilization device comprising a housing having at least one opening, a plasma generator arranged in the housing, and an ultraviolet light source arranged in the housing, wherein: The plasma generator is a plasma exciter provided with a first electrode and a second electrode in a manner of sandwiching a dielectric. The first electrode is disposed on a first surface of the dielectric, and The second electrode is provided on a second surface of the dielectric body opposite to the first surface, and is arranged obliquely across the dielectric body with an offset relative to the first electrode. When a voltage is applied between the first electrode and the second electrode, the plasma actuator generates an induced flow containing ozone from an edge of the first electrode along an exposed portion of the first surface of the dielectric not covered by the first electrode, The plasma actuator is arranged so that the induced flow containing ozone flows from the opening to the outside of the housing to be supplied to the surface of the object to be sterilized, and The ultraviolet light source is arranged to irradiate the surface of the object to be treated, and irradiates the induced flow with ultraviolet light to generate active oxygen in the induced flow.

2. The sterilization device according to claim 1, wherein: The ultraviolet light emitted from the ultraviolet light source has a peak wavelength of 220 nm to 310 nm.

3. The sterilization device according to claim 1 or 2, wherein: The ultraviolet light from the ultraviolet light source has an intensity of 100 μW / cm at a position corresponding to the surface of the object to be processed. 2 or greater illumination.

4. The sterilization device according to claim 1 or 2, wherein: The plasma actuator generates the induced flow, and the ozone concentration of the induced flow is measured to be 20 ppm or higher at a position corresponding to the surface of the object to be processed.

5. A sterilization method using the sterilization device according to any one of claims 1 to 4, wherein the sterilization method comprises the following steps: supplying the induced flow containing ozone to the surface of the object to be sterilized, the induced flow being generated when a voltage is applied between the first electrode and the second electrode; as well as The induction flow containing ozone supplied to the surface of the treatment object is irradiated with ultraviolet light from the ultraviolet light source.

6. The sterilization method according to claim 5, wherein The ultraviolet light has a peak wavelength of 220 nm to 310 nm.

7. The sterilization method according to claim 5 or 6, wherein: The ultraviolet light has an intensity of 100 μW / cm on the surface of the treated object. 2 or greater illumination.

8. The sterilization method according to claim 5 or 6, wherein: The ozone concentration measured on the surface of the treated object is 20 ppm or higher.

9. An active oxygen supply device comprising a housing having at least one opening, a plasma generator disposed in the housing, and an ultraviolet light source disposed in the housing, wherein: The plasma generator is a plasma exciter provided with a first electrode and a second electrode in a manner of sandwiching a dielectric. The first electrode is disposed on a first surface of the dielectric, and The second electrode is provided on a second surface of the dielectric body opposite to the first surface, and is arranged obliquely across the dielectric body with an offset relative to the first electrode. When a voltage is applied between the first electrode and the second electrode, the plasma actuator generates an induced flow containing ozone from an edge of the first electrode along an exposed portion of the first surface of the dielectric not covered by the first electrode, The plasma actuator is arranged so that the induced flow containing ozone flows from the opening to the outside of the housing to be supplied to the surface of the object to be processed, and The ultraviolet light source irradiates the induced flow with ultraviolet light and generates active oxygen in the induced flow.

10. The active oxygen supply device according to claim 9, wherein The ultraviolet light source is arranged to irradiate the object to be processed.

11. A treatment device using active oxygen, comprising a housing having at least one opening, a plasma generator disposed in the housing, and an ultraviolet light source disposed in the housing, wherein: The plasma generator is a plasma exciter provided with a first electrode and a second electrode in a manner of sandwiching a dielectric. The first electrode is disposed on a first surface of the dielectric, and The second electrode is provided on a second surface of the dielectric body opposite to the first surface, and is arranged obliquely across the dielectric body with an offset relative to the first electrode. When a voltage is applied between the first electrode and the second electrode, the plasma actuator generates an induced flow containing ozone from an edge of the first electrode along an exposed portion of the first surface of the dielectric not covered by the first electrode, The plasma actuator is arranged so that the induced flow containing ozone flows from the opening to the outside of the housing to be supplied to the surface of the object to be processed, and The ultraviolet light source irradiates the induced flow with ultraviolet light and generates active oxygen in the induced flow.

12. The treatment device using active oxygen according to claim 11, wherein The ultraviolet light source is arranged to irradiate the object to be processed.

Images