Stain resistant member, lighting device and method for cleaning lighting device

Abstract

To provide a stain resistant member excellent in stain resistance and wear resistance.SOLUTION: A stain resistant member 1 includes a base material 10 and a functional layer 20 coating the base material 10. The functional layer 20 includes a plurality of metal oxide containing nanoparticles 21 and a binder 22 fixed in the state of dispersing the plurality of nanoparticles 21 and including polysiloxane; the surface 23 of the functional layer 20 has unevenness formed by the plurality of nanoparticles 21; and the surface 23 of the functional layer 20 has an average square root height of 10-100 nm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an antifouling member, a lighting device, and a method for cleaning a lighting device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, lighting fixtures having antifouling properties have been known. By imparting antifouling properties to lighting fixtures, it is possible to prevent the lighting fixtures from becoming soiled.

[0003] Patent Document 1 discloses a photocatalyst-carrying lighting fixture that includes a light source that emits light containing an ultraviolet light component in addition to the main light component for illumination, and has a photocatalyst layer on at least a part of the surface of the area that is directly or indirectly irradiated with light from the light source. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4237830 Summary of the Invention [Problem to be solved by the invention]

[0005] The lighting fixture described in Patent Document 1 can promote the decomposition of organic matter using a photocatalyst. However, the anti-fouling effect of the photocatalyst requires that the light component emitted from the light source contains ultraviolet light. Meanwhile, in recent years, lighting fixtures using LED (Light Emitting Diode) light sources have become more common, and anti-fouling properties cannot be expected from such lighting fixtures. Furthermore, while photocatalysts have a strong anti-fouling effect on organic matter, they have not been effective on inorganic matter.

[0006] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide an antifouling member, a lighting device, and a method for cleaning a lighting device that are excellent in antifouling properties and abrasion resistance. [Means for solving the problem]

[0007] In order to solve the above problems, an antifouling member according to a first aspect of the present invention includes a substrate and a functional layer covering the substrate. The functional layer includes a plurality of nanoparticles containing a metal oxide and a binder containing polysiloxane that fixes the plurality of nanoparticles in a dispersed state. The surface of the functional layer is uneven due to the plurality of nanoparticles. The root mean square height of the surface of the functional layer is 10 nm to 100 nm.

[0008] In order to solve the above problem, a lighting device according to a second aspect of the present invention comprises an antifouling member and a light source that irradiates light onto the antifouling member, and a functional layer is arranged on the light exit surface side of the antifouling member.

[0009] In order to solve the above problems, a method for cleaning an illumination device according to a third aspect of the present invention cleans a light exit surface of an antifouling member in an illumination device with air sprayed from an air blowing device. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide an antifouling member, a lighting device, and a method for cleaning a lighting device that are excellent in antifouling properties and abrasion resistance. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view illustrating an example of an antifouling member according to an embodiment. [Figure 2] 1 is a cross-sectional view illustrating an example of a lighting device according to an embodiment. [Figure 3] 1 is a graph showing the relationship between the root mean square height Rq and van der Waals force. DETAILED DESCRIPTION OF THE INVENTION

[0012] The antifouling member, lighting device, and method for cleaning a lighting device according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0013] [Anti-fouling materials] As shown in FIG. 1 , the antifouling member 1 according to this embodiment includes a substrate 10 and a functional layer 20 that covers the substrate 10. The antifouling member 1 may be provided on at least a portion of the surface of the substrate 10. For example, when the substrate 10 is a plate-like member, the functional layer 20 may be provided on at least one surface of the substrate 10. The functional layer 20 may be provided on only one surface of the substrate 10, or on both surfaces of the substrate 10.

[0014] The material of the substrate 10 is not limited, and the substrate 10 may include at least one selected from the group consisting of resin, metal, and glass. The resin may include at least one selected from the group consisting of acrylic resin, polycarbonate resin, styrene resin, and epoxy resin. The metal may include at least one selected from the group consisting of iron, aluminum, magnesium, copper, and titanium.

[0015] The substrate 10 may be light-transmitting. When the substrate 10 has light-transmitting properties, it can be used in the lighting device 100 described below. The total light transmittance of the substrate 10 may be 70% or more, 80% or more, 90% or more, or 100%. The total light transmittance can be measured in accordance with JIS K7361-1:1997.

[0016] The shape of the substrate 10 is not particularly limited, and the substrate 10 may be a plate, a polygonal pillar, a cylinder, a column, a corrugated shape, an irregular shape, etc. The size of the substrate 10 is also not limited, and can be adjusted appropriately depending on the purpose.

[0017] The functional layer 20 includes a plurality of nanoparticles 21 and a binder 22. The binder 22 fixes the plurality of nanoparticles 21 in a dispersed state. The plurality of nanoparticles 21 protrude from a surface 23 of the functional layer 20. The plurality of nanoparticles 21 form unevenness on the surface 23 of the functional layer 20. The root mean square height of the surface 23 of the functional layer 20 is 5 nm to 100 nm.

[0018] Here, the van der Waals force (Rumpf model) taking surface roughness into account is defined by the following mathematical formula (1): See Rabinovich, YI et al., "Adhesion between Nanoscale Rough Surfaces," Journal of Colloid and Interface Science, Vol. 232, (2000), pp. 10-16.

[0019]

number

[0020] In the above formula (1), A represents the Hammerker constant, R represents the particle radius, H0 represents the stable separation distance, and rms represents the root mean square height.

[0021] FIG. 2 is a graph showing the van der Waals force (Rumpf model) taking into account the surface roughness shown in Equation (1) above, for each dirt particle size. The particle sizes of solid dirt present indoors or outdoors vary widely, from a few μm to several hundred μm, and as shown in FIG. 2, the appropriate root mean square height varies depending on the target dirt size. However, if the dirt particles are too small, the dirt will not be noticeable. On the other hand, if the dirt particles are too large, the effect of gravity on the dirt particles will be greater than the intermolecular force, and the dirt particles will easily detach from the functional layer 20.

[0022] Therefore, as shown in FIG. 2, when the target dirt size is several micrometers to several hundred micrometers, the van der Waals force between the functional layer 20 and the solid dirt particles can be reduced by setting the root mean square height of the surface 23 of the functional layer 20 to 5 nm to 100 nm. This configuration makes it difficult for dirt particles to adhere to the surface 23 of the functional layer 20, and even if dirt particles do adhere to the surface 23 of the functional layer 20, they can be easily removed. The target dirt size may be several tens to 100 μm. In such cases, the root mean square height of the surface 23 of the functional layer 20 is preferably 10 nm to 50 nm, more preferably 20 nm to 40 nm, and particularly preferably 20 nm to 33 nm. The root mean square height can be measured in accordance with JIS B0601:2013.

[0023] The thickness of the functional layer 20 is not particularly limited, but may be, for example, 0.1 μm or more and 3 μm or less. If the thickness of the functional layer 20 is 0.1 μm or more, it is possible to prevent the functional layer 20 from being scraped off and exposing the substrate 10. Furthermore, if the thickness of the coating film is 3 μm or less, it is easy to form the functional layer 20 and the amount of material used can be reduced. The thickness of the functional layer 20 may be 0.5 μm or more, or 0.8 μm or more. The thickness of the functional layer 20 may be 2 μm or less, or 1 μm or less.

[0024] The nanoparticles 21 contain a metal oxide. Therefore, as described below, the nanoparticles 21 are strongly bonded to the binder 22. The nanoparticles 21 may contain, for example, at least one selected from the group consisting of silicon dioxide, titanium oxide, aluminum oxide, zinc oxide, cerium oxide, and copper oxide. The nanoparticles 21 may contain at least one of silicon dioxide and titanium oxide. These metal oxides are physically and chemically stable and have high industrial productivity, making it possible to provide a high-quality, mass-producible antifouling member 1. The nanoparticles 21 may contain silicon dioxide. Silicon dioxide has a low refractive index, close to that of air. Therefore, light reflection at the interface between air and the nanoparticles 21 is suppressed, and the light transmittance of the antifouling member 1 can be increased.

[0025] The nanoparticles 21 may be spherical. When the nanoparticles 21 are spherical, the surface 23 of the functional layer 20 is formed with convex portions having spherical surfaces made up of the nanoparticles 21 and concave portions made up of the binder 22 and sandwiched between the convex portions. Because the concave portions are sandwiched between the spherical surfaces, dirt is less likely to clog the valleys. Therefore, compared to using nanoparticles with angular protrusions, for example, clogging can be suppressed, and the antifouling properties of the antifouling member 1 can be further improved.

[0026] In this specification, the concept of the nanoparticles 21 being spherical includes an approximately spherical shape. The spherical nanoparticles 21 may be a perfect sphere or an ellipsoid. The surface of the spherical nanoparticles 21 may be spherical or may have minute smooth irregularities. The aspect ratio of the spherical nanoparticles 21 is preferably 1 or more and 2 or less, and more preferably 1 or more and 1.5 or less. The aspect ratio of the nanoparticles 21 means the ratio of the major axis to the minor axis of the nanoparticles 21 when cut along a cross section passing through the center of the nanoparticles 21.

[0027] The average particle diameter of the plurality of nanoparticles 21 is preferably 20 nm to 100 nm. With this configuration, it is possible to form a root-mean-square height within a predetermined range on the surface 23 of the functional layer 20. The average particle diameter of the plurality of nanoparticles 21 may be 40 nm to 100 nm. The average particle diameter of the plurality of nanoparticles 21 is the average value of the circle-equivalent diameters of the cross sections of the respective nanoparticles 21 measured by observation with a microscope such as an SEM or a TEM.

[0028] The content of nanoparticles 21 in functional layer 20 may be 20% by mass or more and 80% by mass or less. By setting the content of nanoparticles 21 within the above range, unevenness due to nanoparticles 21 can be favorably formed on surface 23 of functional layer 20. The content of nanoparticles 21 may be 30% by mass or more, 40% by mass or more, or 50% by mass or more. Furthermore, the content of nanoparticles 21 may be 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0029] The content of the nanoparticles 21 relative to the nanoparticles 21 and the binder 22 may be 20% by mass or more and 80% by mass or less. By setting the content of the nanoparticles 21 within the above range, it is possible to favorably form unevenness due to the nanoparticles 21 on the surface 23 of the functional layer 20. The content of the nanoparticles 21 may be 30% by mass or more, 40% by mass or more, or 50% by mass or more. Furthermore, the content of the nanoparticles 21 may be 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0030] The binder 22 contains polysiloxane. As described above, the nanoparticles 21 contain a metal oxide. The surfaces of the nanoparticles 21 containing a metal oxide usually have hydroxyl groups. Therefore, not only do siloxanes bond to each other through condensation polymerization or ring-opening polymerization, but the siloxanes also bond to the hydroxyl groups on the surfaces of the nanoparticles 21 to produce polysiloxane. This strengthens the bond between the nanoparticles 21 and the binder 22, making them less likely to detach even when a load is applied to the nanoparticles 21. Therefore, the abrasion resistance of the antifouling member 1 can be improved compared to when, for example, an acrylic resin is used as the binder 22.

[0031] The polysiloxane may have a silanol group (Si—OH). Because silanol groups are highly hydrophilic, a larger amount of moisture is adsorbed onto the surface 23 of the functional layer 20 than dimethylpolysiloxane, etc. The moisture adsorbed onto the surface 23 of the functional layer 20 suppresses charging, thereby improving the antistatic performance of the antifouling member 1.

[0032] The content of the binder 22 in the functional layer 20 may be 20% by mass or more and 80% by mass or less. By setting the content of the binder 22 within the above range, it is possible to favorably form unevenness due to the nanoparticles 21 on the surface 23 of the functional layer 20. The content of the binder 22 may be 30% by mass or more, 40% by mass or more, or 50% by mass or more. The content of the binder 22 may also be 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, or 30% by mass or less.

[0033] The binder 22 may contain at least one binder selected from a water-repellent binder, a hydrophilic binder, and a conductive binder in addition to polysiloxane. Such binders can impart functions such as wettability control and conductivity to the functional layer 20 depending on the application environment and purpose.

[0034] The binder 22 may contain an acrylic resin having at least one of a dimethylsiloxane group and a perfluoroalkyl group. These materials have high water repellency. Therefore, by using such a binder 22, the water repellency of the antifouling member 1 can be improved.

[0035] The content of polysiloxane in binder 22 may be 70% by mass or more and 100% by mass or less. The content of polysiloxane in binder 22 may be 80% by mass or more, 90% by mass or more, or 95% by mass or more. Furthermore, the content of components other than polysiloxane in binder 22 may be 0% by mass or more and 30% by mass or less. The content of components other than polysiloxane in binder 22 may be 20% by mass or less, 10% by mass or less, or 5% by mass or less. The components other than polysiloxane in binder 22 may be an acrylic resin having at least one of the above-mentioned dimethylsiloxane group and perfluoroalkyl group.

[0036] The surface resistance of the functional layer 20 is 10 12 The surface resistance may be 10 Ω / □ or less. 12 When the surface resistance of the functional layer 20 is 10 Ω / □ or less, the antifouling member 1 can be prevented from being charged, and therefore adhesion of dirt particles to the surface of the antifouling member 1 can be prevented. 11 The surface resistance is preferably 10 Ω / □ or less. 10 It is more preferable that the surface resistance is Ω / □ or less. The surface resistance can be measured by a surface resistance meter.

[0037] The functional layer 20 may contain various additives in addition to the nanoparticles 21 and the binder 22. Examples of the various additives include surfactants, surface property modifiers, durability improvers, colorants, UV absorbers, and light stabilizers. The total content of the nanoparticles 21 and the binder 22 in the functional layer 20 may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0038] [Lighting equipment] Next, the lighting device 100 according to this embodiment will be described with reference to Fig. 3. As shown in Fig. 3, the lighting device 100 includes an antifouling member 1 and a light source 110 that irradiates light L1 onto the antifouling member 1. The functional layer 20 is disposed on the light emission surface side of the antifouling member 1. The lighting device 100 includes the antifouling member 1. Therefore, the lighting device 100 according to this embodiment has excellent antifouling properties and abrasion resistance.

[0039] The light source 110 irradiates light L1 onto the stain-resistant member 1. The light L1 irradiated from the light source 110 may include, for example, visible light. The light source 110 is not particularly limited, but may include, for example, an LED. LEDs have a long lifespan, and when the lighting device 100 is used outdoors, it is likely to be left unused for a long period of time. However, since the lighting device 100 is less likely to accumulate dirt, a decrease in luminous flux can be suppressed.

[0040] The lighting device 100 according to this embodiment may be an indoor lighting device, but is particularly excellent as an outdoor lighting device due to its excellent stain resistance and abrasion resistance. The lighting device 100 may be, for example, a road lighting device, a tunnel lighting device, a street lighting device, a floodlight lighting device, etc.

[0041] [How to clean lighting equipment] Next, a method for cleaning the lighting device 100 according to this embodiment will be described. In the method for cleaning the lighting device 100 according to this embodiment, the light exit surface of the antifouling member 1 in the lighting device 100 is cleaned with air sprayed from an air blower.

[0042] In recent years, LEDs have increasingly been used as light sources instead of fluorescent lamps. However, when lighting devices are installed outdoors, dirt such as sand, soot, and tire rubber particles adhere to the lighting device, resulting in a decrease in luminous flux. LEDs have a longer lifespan than fluorescent lamps and are replaced less frequently. Therefore, if lighting devices are left unused for long periods of time, dirt is likely to accumulate on the surface of the lighting device, resulting in a decrease in luminous flux. Furthermore, outdoor lighting devices, such as those on roads and tunnels, have traditionally been cleaned using high-pressure water-spraying vehicles, brush cleaning vehicles, or by hand wiping.

[0043] On the other hand, the lighting device 100 according to this embodiment has excellent stain resistance and abrasion resistance, as described above. Therefore, simply by cleaning the light-emitting surface of the stain-resistant member 1 with air sprayed from an air blower, it is possible to easily remove stains from the lighting device 100 installed outdoors, such as on roads and in tunnels, and to suppress a decrease in luminous flux. Furthermore, because stains on the lighting device 100 can be easily removed with air, it is possible to reduce costs, energy, and manpower compared to conventional cleaning methods.

[0044] The blower for spraying air may be mounted on the vehicle body or may be operated while held by a person. The light-emitting surface of the antifouling member 1 may be cleaned with air sprayed from the air blower while the vehicle body is traveling at or above the legal minimum speed.

[0045] [Method for manufacturing antifouling member] The method for producing an antifouling member includes a preparation step, a coating step, and a curing step, each of which will be described in detail below.

[0046] (preparation process) In the preparation step, the above-described substrate 10 and a coating composition are prepared. The coating composition may contain a binder precursor, the above-described nanoparticles 21, and a solvent.

[0047] The binder precursor is a material that becomes the binder 22 by being cured in the curing step described below. The binder precursor may contain a polysiloxane precursor. The polysiloxane precursor may contain at least one selected from the group consisting of organohalosilanes, organoalkoxysilanes, and cyclic siloxanes. Polysiloxanes can be formed by condensation polymerization of at least one of organohalosilanes and organoalkoxysilanes. Polysiloxanes can also be formed by ring-opening polymerization of cyclic siloxanes. When the binder precursor has silanol groups, the antistatic performance of the antifouling member 1 can be improved, as described above.

[0048] The binder precursor may contain an acrylate having at least one of a dimethylsiloxane group and a perfluoroalkyl group. With this configuration, the water repellency of the antifouling member 1 can be improved as described above.

[0049] The solvent is a material that dissolves the binder precursor and disperses the nanoparticles 21. The solvent may contain an organic solvent. The organic solvent is not particularly limited, but may contain, for example, at least one selected from the group consisting of methyl ethyl ketone, cyclohexanone, isopropanol, and butanol.

[0050] The coating composition may contain various additives, such as surfactants, surface property modifiers, durability improvers, colorants, ultraviolet absorbers, and light stabilizers.

[0051] The content of the nanoparticles 21 relative to the solid content of the coating composition is similar to the content of the nanoparticles 21 in the functional layer 20, and therefore a description thereof will be omitted. The content of the nanoparticles 21 and the solid content of the binder precursor is similar to the content of the nanoparticles 21 relative to the nanoparticles 21 and the binder 22, and therefore a description thereof will be omitted. The content of the solid content of the binder precursor relative to the solid content of the coating composition is similar to the content of the binder 22 in the functional layer 20, and therefore a description thereof will be omitted. The content of the solid content of the polysiloxane precursor relative to the solid content of the binder precursor is similar to the content of the polysiloxane in the binder 22, and therefore a description thereof will be omitted. The content of the solid content of components other than the polysiloxane precursor relative to the solid content of the binder precursor is similar to the content of the solid content of components other than the polysiloxane in the binder 22, and therefore a description thereof will be omitted. The content of the solvent in the coating composition can be set as appropriate.

[0052] (coating process) In the coating step, the coating composition described above is applied to the surface of the cleaned substrate 10. At this time, the method for applying the coating composition is not particularly limited. The coating method or printing method can be used to apply the coating composition to the main surface of the substrate. In the coating method, the coating composition can be applied using an air spray, a brush, a bar coater, a Mayer bar, an air knife, or the like. The coating composition can also be applied by a spin coating method. In the printing method, methods such as gravure printing, reverse gravure printing, offset printing, flexographic printing, and screen printing can be used.

[0053] (hardening process) In the curing step, the binder precursor in the coating composition applied to the surface of the substrate 10 is cured to form the binder 22. The curing conditions can be adjusted appropriately depending on the properties of the coating composition, the film thickness, etc. In the curing step, for example, the coating composition may be heated to dry the solvent and harden the solid content of the coating composition. Through the above steps, an antifouling member 1 can be formed, which includes the substrate 10 and the functional layer 20 containing the nanoparticles 21 and the binder 22.

[0054] (Addendum) The above description of the embodiments discloses the following techniques.

[0055] (Technology 1) An antifouling member comprising a substrate and a functional layer covering the substrate, wherein the functional layer comprises a plurality of nanoparticles containing a metal oxide and a binder containing polysiloxane that fixes the plurality of nanoparticles in a dispersed state, wherein the plurality of nanoparticles form irregularities on the surface of the functional layer, and the root mean square height of the surface of the functional layer is 10 nm to 100 nm.

[0056] The antifouling member includes a plurality of nanoparticles containing a metal oxide and a binder containing a polysiloxane that fixes the plurality of nanoparticles in a dispersed state. The surfaces of the nanoparticles containing a metal oxide usually have hydroxyl groups. Therefore, the siloxane also bonds with the hydroxyl groups on the surface of the nanoparticles, strengthening the bond between the nanoparticles and the binder, making them less likely to detach even when a load is applied to the nanoparticles. Therefore, the antifouling member has excellent abrasion resistance.

[0057] Furthermore, the nanoparticles form irregularities on the surface of the functional layer, and the root mean square height of the surface of the functional layer is 10 nm to 100 nm. This configuration reduces the van der Waals force between the functional layer 20 and the solid matter, i.e., the dirt particles. Therefore, the antifouling member has excellent antifouling properties.

[0058] (Technology 2) The antifouling member according to Technology 1, wherein the nanoparticles are spherical. This configuration can prevent dirt from clogging the recesses of the functional layer. Therefore, the antifouling properties of the antifouling member 1 can be further improved.

[0059] (Technology 3) The antifouling member according to Technology 1 or 2, wherein the nanoparticles contain silicon dioxide. Silicon dioxide has a low refractive index, close to that of air. This can suppress light reflection at the interface between air and the nanoparticles 21, thereby increasing the light transmittance of the antifouling member 1.

[0060] (Technology 4) The antifouling member according to any one of Technologies 1 to 3, wherein the root mean square height of the surface of the functional layer is 10 nm to 50 nm. This configuration further reduces the van der Waals force between the functional layer and the solid substance, i.e., the dirt particles, and thus further improves the antifouling properties of the antifouling member.

[0061] (Technology 5) The antifouling member according to any one of Technologies 1 to 4, wherein the root mean square height of the surface of the functional layer is 20 nm to 40 nm. This configuration further reduces the van der Waals force between the functional layer and the solid substance, i.e., the dirt particles, and thus further improves the antifouling properties of the antifouling member.

[0062] (Technology 6) The antifouling member according to any one of Technologies 1 to 5, wherein the average particle diameter of the nanoparticles is 20 nm to 100 nm. With this configuration, a root-mean-square height within a predetermined range can be formed on the surface of the functional layer. This further improves the antifouling properties of the antifouling member.

[0063] (Technology 7) The antifouling member according to any one of Technologies 1 to 6, wherein the binder contains an acrylic resin having at least one of a dimethylsiloxane group and a perfluoroalkyl group. These materials have high water repellency. Therefore, by using such a binder 22, the water repellency of the antifouling member can be improved.

[0064] (Technology 8) The surface resistance of the functional layer is 10 12 The antifouling member according to any one of techniques 1 to 7, having a resistance of Ω / □ or less. With this configuration, the antifouling member can be prevented from being charged, thereby preventing dirt particles from adhering to the surface of the antifouling member.

[0065] (Technology 9) A lighting device comprising the antifouling member according to any one of Technologies 1 to 8 and a light source that irradiates the antifouling member with light, wherein the functional layer is disposed on the light emitting surface side of the antifouling member. The lighting device comprises the antifouling member, which has excellent antifouling properties and abrasion resistance. Therefore, the lighting device has excellent antifouling properties and abrasion resistance.

[0066] (Technical Field 10) A cleaning method for a lighting device, in which the light-emitting surface of the antifouling member in the lighting device described in Technical Field 9 is cleaned with air sprayed from an air blower. The lighting device has excellent antifouling and abrasion resistance. Therefore, simply by cleaning the light-emitting surface of the antifouling member with air sprayed from an air blower, dirt on a lighting device installed outdoors, such as on a road or in a tunnel, can be easily removed, and a decrease in luminous flux can be suppressed. Furthermore, because dirt on the lighting device can be easily removed with air, costs, energy, and manpower can be reduced compared to conventional cleaning methods. [Example]

[0067] Hereinafter, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples.

[0068] The following materials were prepared to prepare the test samples for each example.

[0069] (base material) Soda glass manufactured by Ikeda Glass Co., Ltd.: length 100mm x width 100mm x thickness 5mm

[0070] (binder precursor) Polysiloxane precursor: Colcoat (registered trademark) PX, manufactured by Colcoat Co., Ltd. Fluorine resin precursor: NOF Corporation, MODIPER (registered trademark) F206 Acrylic resin precursor: Acrydic (registered trademark) DL-967, manufactured by DIC Corporation

[0071] (nanoparticles) Spherical SiO2 (average particle size 10 nm): Nissan Chemical Co., Ltd., MEK-ST-40 Spherical SiO2 (average particle size 50 nm): MEK-ST-L manufactured by Nissan Chemical Co., Ltd. Spherical SiO2 (average particle size 100 nm): MEK-ST-ZL manufactured by Nissan Chemical Co., Ltd. Spherical SiO2 (average particle size 300 nm): Seahoster (registered trademark) KE-S30, manufactured by Nippon Shokubai Co., Ltd. Spherical SiO2 (average particle size 1000 nm): Seahoster (registered trademark) KE-S100, manufactured by Nippon Shokubai Co., Ltd. Spherical TiO2 (average particle size 40 nm): Ishihara Sangyo Kaisha, Ltd., TTO-55 The SiO2 nanoparticles were spherical, while the TiO2 nanoparticles were irregular and nearly spherical, with an aspect ratio of 1 to 2, although not spherical.

[0072] (Preparation of Paint Composition) A mixed solvent was prepared by mixing methyl ethyl ketone and cyclohexanone in a 1:1 ratio. Then, the binder precursor and nanoparticles in the blending ratio (solid content ratio) shown in Tables 1 and 2 were diluted with the mixed solvent to a solid content ratio of 3 mass % to prepare a coating composition.

[0073] The coating composition was applied to one surface of the substrate and heated at 100°C for 10 minutes to form a functional layer with a thickness of approximately 1 µm on the substrate. In this way, test samples for each example were prepared.

[0074] [evaluation] The test samples for each example were evaluated in the table below. The evaluation results are shown in Tables 1 and 2.

[0075] (Root mean square height Rq) The root mean square height Rq was measured using an SPA300HV manufactured by Hitachi High-Tech Science Corporation in accordance with JIS B0601:2013.

[0076] (surface resistance value) The surface resistance value was measured using a surface resistance meter YC-103 manufactured by AS ONE Corporation.

[0077] (Dirt removal rate) On a horizontal test table, artificial soil (42 mesh powder rubber manufactured by Asahi Reclaimed Rubber Co., Ltd.) was passed through a 500 μm mesh sieve manufactured by Iida Seisakusho Co., Ltd., and the artificial soil was uniformly attached to the surface of the test sample. The amount of artificial soil attached to the surface of the test sample was 150 ± 20 mg. The test sample with the artificial soil attached was slowly tilted vertically, then held still for 5 seconds, allowing the soil to fall freely in the vertical direction. The soil removal rate (%) was then calculated using the following formula (2): Dirt removal rate = {(Wa-Wb) / Wa} x 100 (2) In the above formula (2), Wa is the mass of the artificial dirt attached before the free fall, and Wb is the mass of the artificial dirt remaining after the free fall.

[0078] (wear resistance) A dry cotton cloth is applied to the surface of the test sample at 10 gf / cm 2 The cotton cloth was pressed against the surface with a pressure of 1000 psi and then rubbed 200 times. The size of the cotton cloth was 3cm x 3cm, the weight was 90g, and the rubbed area was 3cm x 10cm. The rubbed area was evaluated as "A" if no scratches were found, "B" if there were 1 to 10 scratches in the rubbed area, and "C" if there were more than 10 scratches in the rubbed area.

[0079] [Table 1]

[0080] [Table 2]

[0081] As shown in Table 1, the test samples according to Examples 1 to 5 had a high dirt removal rate and were excellent in stain resistance. Furthermore, the test samples according to Examples 1 to 5 were evaluated as A in abrasion resistance and were excellent in abrasion resistance. Furthermore, the test samples according to Examples 1 to 5 had low surface resistance and were excellent in antistatic properties.

[0082] On the other hand, as shown in Table 2, the test sample according to Comparative Example 1 had a low dirt removal rate and poor antifouling properties due to the absence of a functional layer. The test sample according to Comparative Example 2 had a low dirt removal rate and a B rating for abrasion resistance due to the absence of nanoparticles in the functional layer. The test sample according to Comparative Example 3 had a low dirt removal rate due to a root mean square height of 6.5 nm. The test sample according to Comparative Example 4 had a low dirt removal rate and a B rating for abrasion resistance due to a root mean square height of 125 nm. The test samples according to Comparative Examples 5 and 6 used an acrylic resin as a binder and therefore received a C rating for abrasion resistance. The test sample according to Comparative Example 6 also had a low dirt removal rate due to a root mean square height of 870 nm.

[0083] The results in Tables 1 and 2 show that in the antifouling members according to Examples 1 to 5, the surface of the functional layer was uneven due to the presence of multiple nanoparticles, and the root mean square height of the functional layer surface was 10 nm to 100 nm. Therefore, it can be seen that the antifouling members according to Examples 1 to 5 have a high dirt removal rate and excellent antifouling properties. Furthermore, in the antifouling members according to Examples 1 to 5, the functional layer contains multiple nanoparticles containing a metal oxide and a binder containing polysiloxane that fixes the multiple nanoparticles in a dispersed state. Therefore, it can be seen that the antifouling members according to Examples 1 to 5 have excellent abrasion resistance.

[0084] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0085] 1 Antifouling material 10 Base material 20 Functional Layers 21 Nanoparticles 22 Binder 23 Surface 100 lighting equipment 110 Light source L1 light

Claims

1. A substrate; a functional layer that covers the substrate; Equipped with the functional layer includes a plurality of nanoparticles containing a metal oxide and a binder that fixes the plurality of nanoparticles in a dispersed state and includes a polysiloxane; the plurality of nanoparticles form irregularities on the surface of the functional layer; An antifouling member, wherein the root mean square height of the surface of the functional layer is 10 nm to 100 nm.

2. The antifouling member according to claim 1 , wherein the nanoparticles are spherical.

3. The antifouling member according to claim 1 or 2, wherein the nanoparticles comprise silicon dioxide.

4. The antifouling member according to claim 1 or 2, wherein the root mean square height of the surface of the functional layer is 10 nm to 50 nm.

5. The antifouling member according to claim 1 or 2, wherein the root mean square height of the surface of the functional layer is 20 nm to 40 nm.

6. 3. The antifouling member according to claim 1, wherein the average particle size of the plurality of nanoparticles is 20 nm to 100 nm.

7. 3. The stain-resistant member according to claim 1, wherein the binder contains an acrylic resin having at least one of a dimethylsiloxane group and a perfluoroalkyl group.

8. The surface resistance of the functional layer is 10 １２ The stain-resistant member according to claim 1 or 2, having a resistance to moisture of Ω / □ or less.

9. The antifouling member according to claim 1 or 2; a light source that irradiates the antifouling member with light; Equipped with The functional layer is disposed on the light exit surface side of the antifouling member.

10. A method for cleaning an illumination device, comprising cleaning the light-emitting surface of the antifouling member in the illumination device according to claim 9 with air sprayed from an air blowing device.

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