Articles having a film, paints, and methods for manufacturing articles

Abstract

To provide an article having excellent anti-fouling properties for preventing fouling, such as fingerprints, and excellent heat-shielding properties against sunlight; optical devices; and coating materials.SOLUTION: An article includes a film on a base member, the film at least containing a resin, first particles, and third particles containing second particles in a base material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an article having a film, a paint, and a method for manufacturing an article. In particular, it relates to a film and a paint provided on the surface of an optical device such as a lens barrel of an optical device such as a camera, video, or broadcasting device, and other camera bodies, surveillance cameras, and weather cameras that may be used outdoors.

Background Art

[0002] A film provided on the surface of an optical device such as a camera, video, or broadcasting device is required to have both a design property and further functionality. For example, when a person may touch the device during shooting, fingerprints and oils often adhere, so antifouling property is required. As a paint used for an optical device, antifouling property can be enhanced by making it water-repellent so that dirt hardly adheres, or by making it hydrophilic so that dirt spreads by wetting. Furthermore, there is a known technique of reducing the adhesion of dirt by making the surface have an uneven structure and reducing the contact area of dirt.

[0003] In addition, since such optical devices are often used outdoors, in addition to the antifouling function, heat insulation property for reflecting and diffusing sunlight under severe sunlight conditions such as directly under the equator is also required.

[0004] Patent Document 1 describes a film in which resin beads are added to a paint to form an uneven structure on the surface and enhance the light diffusing property.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In Patent Document 1, the resin beads transmit sunlight, making them ineffective at reflecting sunlight and resulting in low heat shielding effect. When using optical equipment under harsh sunlight conditions such as directly under the equator, there is a risk that the performance of the optical equipment may be reduced due to deformation of the substrate, etc.

[0007] To solve the above problems, the present invention aims to provide articles and coatings having a film on their surface that exhibits excellent heat shielding properties against sunlight. [Means for solving the problem]

[0008] The present invention relates to an article comprising a base material and a film provided on the base material having an uneven surface structure, wherein the film comprises at least a resin, a first particle, and a third particle comprising a second particle encapsulated in a base material. The first particles and the second particles are a mixture of one or more materials selected from titanium dioxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, and aluminum oxide, the average particle size of the first particles is 10 nm or more and 5 μm or less, the content (area %) of the first particles in the resin is 10 area % or more and 80 area % or less, and the content (area %) of the second particles in the base material is 5 area % or more and less than or equal to the content (area %) of the first particles in the resin. The average particle diameter of the third particle is characterized by being larger than the average particle diameter of the first particle and the average particle diameter of the second particle.

[0009] Furthermore, the paint of the present invention is a paint that forms a film having an uneven surface structure, and comprises at least a resin, a first particle, and a third particle in which a second particle is encapsulated in a base material. The first particles and the second particles are a mixture of one or more materials selected from titanium dioxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, and aluminum oxide, the average particle size of the first particles is 10 nm or more and 5 μm or less, the content of the first particles in the resin is 20% by mass or more and 55% by mass or less, and the content of the second particles in the base material is 15% by mass or more and less than or equal to the content of the first particles in the resin. The average particle diameter of the third particle is characterized by being larger than the average particle diameter of the first particle and the average particle diameter of the second particle. [Effects of the Invention]

[0010] We can provide articles, optical instruments, and paints that offer excellent heat shielding properties against sunlight. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the first embodiment. [Figure 2] This is an external view showing one embodiment of the optical instrument of the present invention. [Figure 3] This is a schematic diagram illustrating a method for evaluating heat shielding effectiveness. [Modes for carrying out the invention]

[0012] Preferred embodiments of the present invention will be described below.

[0013] (First Embodiment) Figure 1 shows a partial cross-sectional view of a first embodiment, which is an example of an article according to the present invention. In Figure 1, 1 is a base material, 2 is a resin, 4 is a first particle made of a first material, 3 is a third particle, and base material 6 ni It contains a second particle 5 made of two materials. The substrate 1 is formed on the surface of a plastic or metal substrate by applying the paint of this embodiment, thereby forming a film with excellent heat-shielding properties (the film according to this embodiment).

[0014] The article of this embodiment has a film (the film according to this embodiment) with excellent heat-shielding properties on its surface. As will be described in detail later, the article of this embodiment is particularly suitable for use in optical equipment. Optical equipment is, for example, interchangeable lenses used in cameras, video cameras, broadcasting equipment, etc. In the case of interchangeable lenses, when used outdoors, the film according to this embodiment is formed on the part that is exposed to sunlight (referred to as the outer surface), and the substrate 1 has a holding part inside that holds the lens.

[0015] Alternatively, the optical device may be an image forming device that forms an image using light transmitted through a lens, such as a camera body, video camera body, surveillance camera, or weather camera, which may be used outdoors. The optical device of this embodiment exhibits a higher heat shielding effect by forming the film according to this embodiment on the part that is irradiated by sunlight (referred to as the outer surface) when used outdoors. The optical device of this embodiment has electronic equipment inside the substrate 1 on which the film according to this embodiment is formed on the outer surface, and it is possible to suppress the effects of heat on this electronic equipment.

[0016] Figure 2(a) shows the appearance of an interchangeable lens for a camera including a lens barrel having a holding portion for holding a lens, which is an aspect of the optical device of the present embodiment. The interchangeable lens has a lens barrel 30 and a tripod socket 33, and the lens barrel 30 is composed of a lens, a fixed cylinder 31, an annular member 32, and the like. In the optical device of the present embodiment, a film (the film according to the present embodiment) excellent in heat shielding performance is formed on the surfaces of the fixed cylinder 31, the annular member 32, the tripod socket 33, and the like of the lens barrel 30. By suppressing deformation due to heat of the fixed cylinder 31, the annular member 32, the tripod socket 33, and the like, a decrease in accuracy can be suppressed, and a high-precision image can be formed. The materials of the fixed cylinder 31, the annular member 32, and the tripod socket 33 are not particularly limited, and may be plastic or metal.

[0017] The film according to the present embodiment includes at least a resin 2, first particles 4 made of a first material, and a base material 6. ni The film of the present embodiment further includes third particles 3 including second particles 5 made of a second material. The film of the present embodiment includes the third particles 3 including the second particles 5 made of a second material, so that the surface becomes uneven, and dirt such as fingerprints is difficult to attach. Also, since it reflects light in the visible and near-infrared ranges, the heat shielding performance is improved. <s ni The material of the base material 6 of the third particles 3 is not particularly limited and may be any material, but a resin having high transparency, low specific gravity is preferable. For example, it may include one or more types selected from acrylic resin, epoxy resin, polyester resin, polyolefin resin, polyurethane resin, and melamine resin. The type can be selected according to the base material, application, and the like.

[0018]

[0019] ​The materials of the first particles 4 and the second particles 5 (the particles included in the base material 6) are not particularly limited as long as they are materials with high visible or near-infrared reflectivity. For example, a material obtained by mixing one or more materials selected from titanium oxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, and alumina can be used. Among these, it is preferable that the main component is titanium oxide with high visible or near-infrared reflectivity, and more preferably that the main component is rutile-type titanium oxide. When the main component is rutile-type titanium oxide, in addition to high visible or near-infrared reflectivity, high light resistance can be imparted.

[0020] Also, the second particles may be particles in which the surface of titanium oxide is coated with silica, zirconia, alumina, etc. for the purpose of further enhancing light resistance. The materials of the first particles 4 and the second particles 5 may be the same material or different materials.

[0021] As the shape of the third particles 3 of the present embodiment, it is preferably spherical for forming an uneven structure. In this specification, spherical means that the average roundness is 0.8 or more. The average roundness being 0.8 or more means that samples of the cross-section of the film are cut out at five locations, magnified with a microscope, and for each sample, ten cross-sections of the third particles 3 are observed. It means that the average roundness of the third particles 3 in the observed 10×5 samples is 0.8 or more. The roundness is calculated from the following formula. Roundness = 4π (area of the cross-section) / (perimeter of the cross-section)

[0022] Furthermore, the average particle diameter of the third particle 3 is preferably greater than 1 μm and 50 μm or less, and more preferably between 10 μm and 30 μm. If the third particle 3 in this embodiment is 1 μm or less, it is difficult to form an uneven structure, and dirt will adhere easily. If it is greater than 50 μm, there is a risk that the third particle 3 will be exposed from the film surface, and if it is exposed, the aesthetic appeal will be impaired. In this specification, the third particle 3 is defined as a particle with an average particle diameter of 1 μm or more and 50 μm or less. The average particle diameter of the third particle 3 is the average particle diameter based on the number of particles, and in the case of the paint state before application, it can be measured by dynamic light scattering. When measuring from the state of the film, first, a sample of the cross-section of the film according to this embodiment is cut in five places and magnified with a microscope. In this specification, the cross-section of the film is defined as a cut in a direction parallel to the normal direction of the film surface. The normal direction of the film surface is the normal direction of the plane connecting the convex portions if there are irregularities on the film surface. Next, the third particle 3 is subjected to surface analysis using Energy Dispersive X-ray Spectroscopy (EDS) at five locations to determine the particle diameter of each third particle 3, and then the average value is calculated. In this specification, the maximum transverse length of the particle is defined as the particle diameter. Ten or more particle diameters are determined at each location, and the average value is calculated. Finally, the average value of the five locations is calculated. This average value of the five locations is taken as the average particle diameter of the third particle 3 contained in the film according to this embodiment.

[0023] The content of the third particle 3 in the film is preferably 5 area% to 80 area%, and more preferably 30 area% to 60 area%. If the content of the third particle 3 is less than 5 area%, the uneven structure will become sparse, which may worsen the antifouling properties. Also, if the content of the third particle 3 exceeds 60 area%, the adhesion to the substrate may worsen. The content of the third particle 3 in the film according to this embodiment can be measured as follows. First, five cross-sections of the film according to this embodiment are cut and magnified with a microscope. The cross-sections of the film are cut in a direction parallel to the normal direction of the film surface. Next, the third particle 3 is analyzed at the five locations using Energy Dispersive X-ray Spectroscopy (EDS), and the content of the third particle 3 per unit area is calculated. Finally, the content of the third particle 3 in the film according to this embodiment is calculated from the average value of the five locations, and this value is taken as the content (area %) of the third particle 3 in the film.

[0024] The particle size of the first particle 4 is preferably such that the average particle diameter is 10 nm or more and 5 μm or less, and more preferably 100 nm or more and 1 μm or less. If the average particle diameter of the first particle 4 in this embodiment is smaller than 10 nm, it will not be able to effectively reflect visible or infrared light, and the heat shielding performance will decrease. Also, if the average particle diameter of the first particle 4 in this embodiment exceeds 5 μm, it will be difficult to uniformly disperse it in the resin 2, and the heat shielding performance may be impaired. The content (area %) of the first particle 4 in the resin 2 is preferably 10 area % or more and 80 area % or less, more preferably 30 area % or more and 60 area % or less. If it is less than 10 area % the heat shielding performance will decrease, and if it is more than 80 area % the film will be brittle and prone to cracking in environments with rapid temperature changes, etc.

[0025] In the film according to this embodiment, the content of the first particles 4 relative to the resin 2 (the area %) of the first particles when the area of ​​the resin in the cross-section is set to 100 area %) can be measured as follows. First, five sections are cut from the cross-section of the film and magnified with a microscope. The cross-sections of the film are cut in a direction parallel to the normal direction of the film surface. The normal direction of the film surface is the normal direction of the plane connecting the convex portions if there are irregularities on the film surface. Next, the resin 2 and the first particles 4 are analyzed at each of the five locations using Energy Dispersive X-ray Spectroscopy (EDS) to determine the area %) of the first particles 4 when the area of ​​the resin 2 is set to 100 area %).

[0026] The particle size of the first particle 4 is preferably 10 nm or more and 5 μm or less, and more preferably 100 nm or more and 1 μm or less. If the average particle size of the first particle 4 in this embodiment is smaller than 10 nm, it will not be able to effectively reflect visible or infrared light, and the heat shielding performance will decrease. Also, if the average particle size of the first particle 4 in this embodiment exceeds 5 μm, it will be difficult to disperse it uniformly in the resin, and the heat shielding performance may be impaired.

[0027] The average particle diameter of the first particle 4 is the average particle diameter based on the number of particles, and in the case of the paint before application, it can be measured by dynamic light scattering. When measuring from the state of the film, first, five cross-sectional samples of the film according to this embodiment are cut out and magnified with a microscope. Next, the first particle 4 is analyzed at each of the five locations using Energy Dispersive X-ray Spectroscopy (EDS) to determine the particle diameter of each first particle 4, and the average value is calculated. The average value is calculated by obtaining the particle diameters of 10 or more particles at each location. Finally, the average value of the five locations is calculated. This average value of the five locations is taken as the average particle diameter of the first particle 4 contained in the film according to this embodiment.

[0028] The film according to this embodiment is characterized in that the content (area %) of the second particles 5 in the base material is 5 area % or more, and less than or equal to the content (area %) of the first particles 4 in the resin. The content (area %) of the second particles 5 in the base material in this embodiment is the area % of the second particles 5 when the area of ​​the base material in the cross-section is set to 100 area %. If it is less than 5 area %, the third particles 6 as a whole have high transmittance of visible or infrared light, and light cannot be efficiently discharged to the outside of the film. Also, if it is greater than the content (area %) of the first particles 4 in the resin, the light incident on the third particles 3 becomes trapped inside the third particles 3, and the light cannot be discharged to the outside of the film. The inventors have found that even in a film containing large-sized particles (third particles) mainly composed of a highly transparent resin, it is possible to achieve the desired heat shielding performance by incorporating small second particles within the above range inside the large-sized particles (third particles).

[0029] The content (area %) of the second particle 5 relative to the base material in the film according to this embodiment can be measured as follows. First, five cross-sections of the film according to this embodiment are cut and magnified with a microscope. The cross-sections of the film are cut in a direction parallel to the normal direction of the film surface. Next, the third particle 3 is analyzed at the five locations using Energy Dispersive X-ray Spectroscopy (EDS), and the area of ​​the base material and the area of ​​the second particle contained in the third particle are calculated. Then, the area % of the second particle relative to the base material is determined. For each of the five cross-sections, the area % of the second particle relative to the base material is determined and averaged. This averaged value is taken as the content (area %) of the second particle 5 relative to the base material.

[0030] Furthermore, the film of this embodiment preferably has a brightness of 50 or more and 80 or less. By adjusting the content of the first particles and the second particles in the third particles, it is possible to adjust the brightness of the film to 50 or more. In this embodiment, if the brightness of the film is less than 50, the solar reflectance decreases, and the temperature reduction effect deteriorates. If the brightness of the film formed using the paint of this embodiment exceeds 80, the color may become too white, making dirt more noticeable.

[0031] (resin) The resin 2 content in the film of this embodiment is preferably 5 area% to 80 area% and more preferably 30 area% to 60 area%. If the resin 2 content in this embodiment is less than 5 area%, the adhesion to the substrate may deteriorate. Also, if the resin content in this embodiment exceeds 60 area%, the uneven structure necessary for stain resistance may not be achieved. The resin 2 in the film of this embodiment is not particularly limited, but examples include cured epoxy resin, urethane resin, acrylic resin, urethane acrylic resin, phenolic resin, and alkyd resin. These cured resins may be of one type or may contain multiple types. They may also be the same material as the base material of the third particle.

[0032] The resin 2 content in the film according to this embodiment can be measured as follows. First, the content (area %) of the third particle 3 in the film according to this embodiment is calculated using the method described above. Next, five cross-sections of the film that do not contain the third particle 3 are cut out and magnified with a microscope. Then, the resin is analyzed at the five locations using Energy Dispersive X-ray Spectroscopy (EDS), and the area %) of the resin 2 is determined when the area of ​​the cross-section is set to 100 area %. For example, suppose that when the cross-section is set to 100 area %, the area of ​​the resin 2 contained in that cross-section is 50 area %. The resin 2 content (area %) contained in the area % obtained by subtracting the content (area %) of the third particle 3 from 100% is calculated. For example, if the content of the third particle 3 is 40 area %, the area % obtained by subtracting the content (area %) of the third particle 3 from 100% is 60 area %. Since 50% of the 60% area is resin, the resin content in the film according to this embodiment is 30%. Finally, the average value of the five locations is calculated and given as the resin content (area %) in the film.

[0033] (base material) Any material can be used as the base material, but metals and plastics are preferred. Examples of metal materials include aluminum, titanium, stainless steel, magnesium alloys, and lithium-magnesium alloys. Examples of plastics include polycarbonate resin, acrylic resin, ABS resin, fluororesin, polyester resin, melamine resin, and polyvinyl chloride resin.

[0034] Furthermore, while the film thickness of the substrate can be any thickness, it is preferably 0.5 mm to 5 mm, and more preferably 0.5 mm to 2 mm. If the film thickness is less than 0.5 mm, it becomes difficult to maintain the shape of the lens barrel. Also, if the film thickness exceeds 5 mm, the cost of the component increases.

[0035] (Primer) The substrate may have a primer at its interface with the film in order to improve adhesion to the film.

[0036] Any material can be used as the primer, but examples include epoxy resin, urethane resin, acrylic resin, silicone resin, and fluororesin. The primer may also contain the particles of this embodiment or particles other than those of this embodiment. Furthermore, it may contain colorants, dispersants, curing agents, curing catalysts, plasticizers, thixotropic agents, leveling agents, organic colorants, inorganic colorants, preservatives, UV absorbers, antioxidants, coupling agents, and solvent residues.

[0037] Furthermore, the primer film thickness is preferably 2 μm to 30 μm, and more preferably 5 μm to 20 μm. If the film thickness is less than 2 μm, the adhesion of the film may decrease, and if it exceeds 30 μm, it may adversely affect the positional accuracy of the optical instrument.

[0038] In this specification, the term "substrate" may refer to both the substrate and the primer together. In other words, in this specification, the substrate may include the primer.

[0039] (Film thickness) The film according to this embodiment preferably has a film thickness of 20 μm or more and 70 μm or less. If the film thickness is less than 20 μm, the solar reflectance may decrease. If it is 70 μm or more, it may adversely affect the positional accuracy of the optical instrument.

[0040] (Particles used to adjust the brightness of the film) The film according to this embodiment may contain particles (colorants) for adjusting brightness in addition to the first and second particles described above. The material of the particles is not particularly limited, but it is preferable to include azo-based organic particles that have high infrared reflectivity. Any particles of a compound having an azo group can be used as the azo-based organic particles. Examples of the colors of the azo-based organic particles included in the film of this embodiment include black, yellow, red, and orange, but black is more preferable because it shows less color change (a*, b*) when fading occurs due to sunlight. It is also preferable that the reflectivity of sunlight is high, and it is preferable to select a material in which the solar reflectance of the azo-based organic particles alone exceeds 10%. Examples of azo-based organic particles include nickel azo pigments, insoluble azo pigments, soluble azo pigments, high molecular weight azo pigments, and azomethine azo pigment-based pigments. One type of these azo-based organic particles may be used, or multiple types may be included.

[0041] The average particle diameter of the azo organic particles contained in the film of this embodiment is preferably 10 nm to 5 μm, and more preferably 50 nm to 2 μm. If the average particle diameter is less than 10 nm, the surface area of ​​the particles increases, which can worsen light resistance and cause discoloration. If the average particle diameter exceeds 5 μm, it becomes difficult to uniformly disperse the particles in the film, which may impair the heat shielding performance. The average particle diameter of the azo organic particles is the average particle diameter based on the number of particles, and in the case of the paint before application, it can be measured by dynamic light scattering. When measuring from the state of the film, first, a sample of the cross-section of the film according to this embodiment is cut in five places and magnified with a microscope. The cross-section of the film is cut in a direction parallel to the normal direction of the film surface. The normal direction of the film surface is the normal direction of the plane connecting the convex parts if there are irregularities on the film surface. Next, azo organic particles are analyzed at five locations using Energy Dispersive X-ray Spectroscopy (EDS) to determine the particle diameter of each azo organic particle, and then the average value is calculated. In this specification, the maximum transverse length of a particle is defined as the particle diameter. Ten or more particle diameters are determined at each location, and the average value is calculated. Finally, the average value of the five locations is calculated. This average value of the five locations is taken as the average particle diameter of the azo organic particles contained in the film according to this embodiment.

[0042] The content of azo organic particles in the film according to this embodiment is preferably 0.1 area% to 0.4 area%, and more preferably 0.15 area% to 0.3 area%. If the content of azo organic particles is less than 0.1 area%, the brightness of the film becomes too high, and the antifouling properties deteriorate. If the content of azo organic particles is 0.4 area% or more, the brightness of the film becomes too low, and the solar reflectance deteriorates. The content of azo organic particles in the film according to this embodiment can be measured as follows. First, the content (area %) of the third particle 3 in the film according to this embodiment is calculated using the method described above. Next, five cross-sections of the film that do not contain the third particle 3 are cut out and magnified with a microscope. Next, surface analysis is performed on the five locations using Energy Dispersive X-ray Spectroscopy (EDS), and the content (area %) of azo organic particles contained in the area % obtained by subtracting the content (area %) of the third particle 3 from 100% is calculated. For example, if the content of the third particle 3 is 40 area%, then subtracting the content of the third particle 3 (area%) from 100% gives an area percentage of 60 area%. If 1 area% of azo organic particles is contained within that 60 area%, then the content of azo organic particles is 0.6 area%. Finally, the average value of the five locations is calculated and used as the content (area%) of azo organic particles contained in the membrane.

[0043] (Silica particles) The film according to this embodiment may further contain silica particles. The average particle size of the silica is preferably 10 nm or more and 5 μm or less. If the average particle size of the silica in this embodiment is less than 10 nm, it is difficult to form a surface uneven structure, making it easier for dirt to adhere, and if it is 5 μm or more, the unevenness of the coating film becomes large, which may adversely affect the positional accuracy of the optical instrument.

[0044] The silica particles can be of any shape. Examples of silica particle shapes include spherical, amorphous, star-shaped, chain-like, hollow, and porous. These silica particles can be of one type or a combination of multiple types.

[0045] In this embodiment, the particle diameter of the silica particles is the average particle diameter based on the number of particles. The average particle diameter of the silica particles can be measured by dynamic light scattering when the paint is in its pre-coating state. When measuring from the state of the film, first, five cross-sectional samples of the film according to this embodiment are cut and magnified with a microscope. Next, the silica particles at the five locations are analyzed using Energy Dispersive X-ray Spectroscopy (EDS) to determine the particle diameter of each silica particle, and the average value is calculated. The average value is calculated by obtaining the particle diameters of 10 or more particles at each location. Finally, the average value of the five locations is calculated. This average value of the five locations is taken as the average particle diameter of the silica contained in the film according to this embodiment.

[0046] (Other additives) The film according to this embodiment may contain other optional additives. Examples include dispersants, curing agents, curing catalysts, plasticizers, thixotropic agents, leveling agents, matting agents, preservatives, UV absorbers, antioxidants, coupling agents, and inorganic and organic fine particles for adjusting the color other than those mentioned above.

[0047] "paint" Next, the paint of this embodiment and the method for manufacturing the same will be described.

[0048] The paint of this embodiment includes at least a resin and a third particle and a first particle that encompass a second particle.

[0049] (The third particle) The base material 26 of the third particle 23 contained in the paint of this embodiment is not particularly limited and may be any material, but a resin that is highly transparent and has a low specific gravity is preferred. For example, it may contain one or more types selected from acrylic resin, epoxy resin, polyester resin, polyolefin resin, polyurethane resin, and melamine resin.

[0050] The material of the second particle 25 contained within the third particle 23 is not particularly limited, and for example, titanium oxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, alumina oxide, etc. can be used. Of these, titanium oxide, which has a high reflectivity of visible or near-infrared light, is preferred. In addition, the second particle 25 may be made of a material coated with silica, zirconia, alumina, etc. on its surface for purposes such as improving light resistance.

[0051] In this embodiment, the third particle 23 is preferably particulate in order to form an uneven structure. Furthermore, the average particle diameter of the third particle 23 is preferably 1 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less. If the third particle 23 in this embodiment is 1 μm or less, an uneven structure is difficult to form, and dirt tends to adhere easily. If it is 30 μm or more, the third particle 23 may be exposed from the film surface, and if exposed, the aesthetic appearance will be impaired. The particle diameter of the third particle 23 is the average particle diameter based on the number of particles, and can be measured by dynamic light scattering.

[0052] The content of the third particles 23 in the paint of this embodiment is preferably 0.5% by mass or more and 20% by mass or less, and more preferably 1% by mass or more and 15% by mass or less, relative to the non-volatile components in the paint. If the content of the third particles 23 is less than 0.5% by mass, the uneven structure will become sparse, and the antifouling properties may deteriorate. Also, if the content of the third particles 23 is 20% by mass or more, the adhesion to the substrate may deteriorate. The content of the third particles 23 relative to the non-volatile components in the paint can be measured by performing centrifugation and separating it as sediment.

[0053] The content of the second particles 25 contained within the base material 26 of the third particles 23 in the paint of this embodiment is preferably 15% by mass or more relative to the base material, and less than or equal to the content of the first particles 24 relative to the resin, as described later. "Relative to the base material" refers to the mass content (%) (content (mass%)) when the base material is set to 100% by mass. If it is less than 15% by mass, the third particles 23 as a whole will have high transmittance of visible or infrared light, and will not be able to efficiently discharge light to the outside of the film. Also, if it is greater than the content of the first particles 24 in the resin, it is thought that the light incident on the third particles 23 will be trapped inside the third particles 23, and the heat shielding performance will decrease.

[0054] The method for producing the third particle 23 is not particularly limited. For example, it may be produced by polymerization such as suspension polymerization using a dispersion in which the second particle 25 is dispersed in a monomer that serves as the base material 26. Alternatively, a curing agent may be added to the dispersion and cured, and then the cured product may be produced by grinding it using a mechanical rotary or jet type fine grinder. Furthermore, it may be classified to obtain a desired particle size.

[0055] (First particle) The material of the first particle 24 contained in the paint of this embodiment can be the same as that of the second particle 25 that is enclosed inside the third particle 23.

[0056] The content of the first particles 24 in the paint of this embodiment is preferably 20% by mass or more and 55% by mass or less relative to the resin in the paint (when the resin in the paint is considered to be 100% by mass), and more preferably more than 20% by mass and 45% by mass or less. If the content of the first particles 24 in this embodiment is less than 20% by mass, the heat shielding effect will decrease. If the content exceeds 55% by mass, the particles will not be uniformly dispersed in the paint film, causing unevenness in the film. The content of the first particles 24 in the paint can be separated as sediment by appropriate centrifugation and measured by a Fourier transform infrared spectrophotometer (FT-IR).

[0057] The average particle diameter of the first particles 24 is preferably 10 nm or more and 5 μm or less, and more preferably 100 nm or more and 1 μm or less. If the average particle diameter of the first particles 24 in this embodiment is smaller than 10 nm, it will not be able to effectively reflect visible or infrared light, and the heat shielding performance will decrease. Also, if the average particle diameter of the first particles 24 in this embodiment exceeds 5 μm, it will be difficult to disperse them uniformly in the resin, and the heat shielding performance may be impaired.

[0058] The average particle diameter of the first particle 24 is the average particle diameter based on the number of particles, and in the case of the paint before application, it can be measured by dynamic light scattering.

[0059] (resin) The resins included in the paint of this embodiment are not particularly limited, but examples include epoxy resin, urethane resin, acrylic resin, urethane acrylic resin, phenolic resin, and alkyd resin. These resins may be one type or multiple types may be included.

[0060] Examples of resins include epoxy resin, urethane resin, acrylic resin, urethane-acrylic resin, phenolic resin, and alkyd resin. These resins may be used individually or in combination of multiple types.

[0061] Furthermore, the resin content in the paint of this embodiment is preferably 5% by mass or more and 80% by mass or less relative to the non-volatile components in the paint (when the non-volatile components in the paint are considered to be 100% by mass), and more preferably 15% by mass or more and 50% by mass or less. If the resin content of this embodiment is less than 5% by mass, the adhesion to the substrate may deteriorate. Also, if the resin content of this embodiment exceeds 50% by mass, the uneven structure necessary for antifouling may not be achieved. The resin content relative to the non-volatile components in the paint can be separated as sediment by appropriate centrifugation and measured by a Fourier transform infrared spectrophotometer (FT-IR).

[0062] (Particles used to adjust the brightness of the film) The paint according to this embodiment may also contain particles (colorants) for adjusting brightness in addition to the first and second particles described above. If the first or second particle is, for example, titanium dioxide, it functions as a particle for adjusting brightness (white pigment). The material of the particles is not particularly limited, but it is preferable to include azo-based organic particles that have high infrared reflection performance. Any particles of a compound having an azo group can be used as the azo-based organic particles. Examples of the colors of the azo-based organic particles included in the paint of this embodiment include black, yellow, red, and orange, but black is more preferable because it shows less color change (a*, b*) when fading occurs due to sunlight. It is also preferable that the reflectance of sunlight is high, and it is preferable to select a material in which the solar reflectance of the azo-based organic particles alone exceeds 10%. Examples of azo-based organic particles include nickel azo pigments, insoluble azo pigments, soluble azo pigments, high molecular weight azo pigments, azomethine azo pigments, and so on. These azo organic particles may consist of one type or a combination of multiple types.

[0063] The average particle size of the azo organic particles contained in the coating of this embodiment is preferably 10 nm to 5 μm, and more preferably 50 nm to 2 μm. If the average particle size is less than 10 nm, the surface area of ​​the particles increases, which can worsen light resistance and cause discoloration. If the average particle size exceeds 5 μm, it becomes difficult to uniformly disperse titanium dioxide in the film, which may impair the heat shielding performance. The average particle size of the azo organic particles is the average particle size based on the number of particles and can be measured by dynamic light scattering.

[0064] The content of azo organic particles in the paint of this embodiment is preferably 0.1% by mass or more and 1.0% by mass or less relative to the non-volatile components in the paint, and more preferably 0.15% by mass or more and 0.5% by mass or less. If the content of azo organic particles is less than 0.1% by mass, the brightness of the film may become too high, potentially worsening its antifouling properties. Conversely, if the content of azo organic particles is 1.0% by mass or more, the brightness of the film may become too low, worsening its solar reflectance. The content of azo organic particles relative to the non-volatile components in the paint can be separated as sediment by appropriate centrifugation and measured using a Fourier transform infrared spectrophotometer (FT-IR).

[0065] The particles used to adjust the brightness of the film may include materials other than white pigments (first particles, second particles) and azo organic particles. Examples of such materials include alumina, zirconia, silica, hollow silica, zinc oxide, and pigments. These materials may be used individually or in combination. Inorganic and organic microparticles may also be used to adjust the desired brightness, gloss, and color.

[0066] (Silica particles) The paint of this embodiment may further contain silica particles. Preferably, the average particle size of the silica is 10 nm or more and 5 μm or more. If the average particle size of the silica in this embodiment is less than 10 nm, it becomes difficult to form a surface uneven structure, making it easier for dirt to adhere, and if it is 5 μm or more, the unevenness of the coating film becomes large, which may worsen the accuracy of the film thickness.

[0067] The silica particles can be of any shape. Examples of silica particle shapes include spherical, amorphous, star-shaped, chain-like, hollow, and porous. These silica particles can be of one type or a combination of multiple types.

[0068] In this embodiment, the average particle diameter of the silica particles is the average particle diameter based on the number of particles, and the average particle diameter of the silica particles can be measured by dynamic light scattering when the paint is in its pre-coating state.

[0069] The silica particle content is 0.5% by mass or more and 10% by mass or less relative to the non-volatile components in the paint, preferably 1% by mass or more and 5% by mass or less. If the silica content is less than 0.5% by mass, the reflected light from the film surface may adversely affect the image quality. Also, if the silica particle content in this embodiment exceeds 10% by mass, there is a risk of sedimentation and accumulation in the paint. The silica particle content relative to the non-volatile components in the paint can be separated as sediment by appropriate centrifugation and measured by a Fourier transform infrared spectrophotometer (FT-IR).

[0070] (solvent) The paint of this embodiment further contains a solvent.

[0071] The solvent material is not particularly limited, but examples include water, paint thinner, ethanol, isopropyl alcohol, n-butyl alcohol, ethyl acetate, propyl acetate, isobutyl acetate, and butyl acetate. Other examples include methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, toluene, xylene, acetone, cellosolves, glycol ethers, and ethers. These solvents may be one type or a combination of several types.

[0072] The preferred viscosity of the paint in this embodiment is 10 mPa·s or more and 10,000 mPa·s or less, and more preferably 50 mPa·s or more and 500 mPa·s or less. If the viscosity of the paint is less than 10 mPa·s, there may be areas where the thickness of the heat-shielding film after application is thin. Also, if it exceeds 10,000 mPa·s, the applicability of the paint may decrease.

[0073] (Other additives) The film according to this embodiment may contain other optional additives. Examples include dispersants, curing agents, curing catalysts, plasticizers, thixotropic agents, leveling agents, matting agents, preservatives, UV absorbers, antioxidants, coupling agents, and inorganic and organic fine particles for adjusting the color other than those mentioned above.

[0074] (Method of manufacturing paint) The following describes the manufacturing method of the paint.

[0075] The method for manufacturing the paint to form the film according to this embodiment is not particularly limited, as long as the resin of this embodiment, the third particle containing the second particle in the base material, and the first particle can be dispersed in the paint. Examples include bead mills, ball mills, jet mills, three-roller mills, planetary rotating devices, mixers, ultrasonic dispersers, homogenizers, and the like.

[0076] Methods for manufacturing articles The method for manufacturing an article according to this embodiment is not particularly limited as long as the coating method and curing method can be applied to the substrate with a thickness of 20 μm to 70 μm.

[0077] Application methods include brush application, spray application, dip coating, and transfer. The film in this embodiment may be a single-layer or multi-layer coating. Curing methods include leaving it at room temperature, accelerating curing with heat, or applying ultraviolet light. Methods for curing with heat include heating furnaces, heaters, and infrared heating. The curing temperature is preferably from room temperature to 400°C, and more preferably from room temperature to 200°C.

[0078] Thus, in the article according to this embodiment, a film with excellent heat-shielding properties (the film according to this embodiment) is formed on the surface by applying the paint of this embodiment to the substrate.

[0079] (Second embodiment) Figure 2(b) shows a cross-sectional view of a single-lens reflex digital camera, which is an optical device according to this embodiment, and includes a lens barrel with a holding portion for holding the lens, to which an interchangeable lens is attached.

[0080] The optical equipment according to this embodiment refers to equipment equipped with an optical system including optical elements, such as binoculars, microscopes, semiconductor exposure apparatus, interchangeable lenses, and cameras. Alternatively, it refers to equipment that generates an image using light that has passed through the optical elements. Furthermore, the optical equipment according to this embodiment may also be a camera system such as a digital still camera or a digital video camera, or an electronic device such as a mobile phone that has an image sensor that receives light that has passed through the optical elements of the present invention. In addition, the imaging device may be in the form of a module mounted on the equipment, for example, a camera module.

[0081] Furthermore, the optical device according to this embodiment may be a camera body, video unit, surveillance camera, weather camera, etc., which are image forming devices that form images using light transmitted through a lens and may be used outdoors. When the optical device of this embodiment is used outdoors, a higher heat shielding effect is achieved by forming the film according to this embodiment on the part that is irradiated by sunlight (referred to as the outer surface). With the optical device of this embodiment, by housing electronic equipment inside the substrate 1 on which the film according to this embodiment is formed on the outer surface, it is possible to suppress the effects of heat on the electronic equipment.

[0082] In Figure 2(b), 602 is the camera body and 620 is the outer barrel of the lens barrel. The film of the present invention is formed on the surface of this outer barrel. Figure 2(b) shows the camera body 602 and the interchangeable lens 601, which includes the outer barrel 620 of the lens barrel, coupled together, but the interchangeable lens 601 is detachable from the camera body 602.

[0083] Light from the subject passes through an optical system consisting of multiple lenses 603, 605, etc., arranged on the optical axis of the photographic optical system within the interchangeable lens 601, and is received by the image sensor.

[0084] Here, the lens 605 is supported by a retaining portion formed in the inner barrel 604 of the lens barrel, and is movably supported relative to the outer barrel 620 of the lens barrel for focusing and zooming.

[0085] During the observation period before shooting, light from the subject is reflected by the main mirror 607 inside the camera body housing 621, passes through the prism 611, and the image is projected onto the photographer through the viewfinder lens 612. The main mirror 607 is, for example, a half-mirror, and the light that passes through the main mirror is reflected by the sub-mirror 608 towards the AF (autofocus) unit 613, and this reflected light is used, for example, for distance measurement. The main mirror 607 is also attached and supported by the main mirror holder 640 by adhesive or other means. During shooting, the main mirror 607 and sub-mirror 608 are moved out of the optical path via a drive mechanism (not shown), the shutter 609 is opened, and the image of the photographic light incident from the lens barrel 601 is projected onto the image sensor 610. The aperture 606 is configured to change the brightness and depth of field during shooting by changing the aperture area. [Examples]

[0086] The following describes preferred embodiments of the present invention.

[0087] The preparation of the coatings, the fabrication of the films, and the evaluation of the films in Examples 1 to 3 were carried out by the following methods.

[0088] <How to determine particle size and content> The samples used for measurement were measured in film form. For the measurement samples, a film of the present invention was formed on a polycarbonate resin sheet measuring 50 mm x 70 mm and 1 mm thick. The film was coated onto a polycarbonate resin sheet using a spin coater to the desired film thickness and then fired. After firing, the film was cut in a direction parallel to the normal direction of the film surface, and the cross-section was magnified using a scanning electron microscope (product name: ULTRA55, manufactured by Carl Zaiss). Next, the target substance was subjected to surface analysis using Energy Dispersive X-ray Spectroscopy (EDS) (product name: X-Flash4010, manufactured by Bruker AXS) to determine the particle size of each particle and calculate its average value. For the third particle, the particle sizes of 10 or more particles were determined at each location and the average value was calculated. Finally, the average value of the five locations was calculated.

[0089] Furthermore, the content was determined by taking cross-sections of the film according to this embodiment at five locations and magnifying the cross-sections with a scanning electron microscope (product name: ULTRA55, manufactured by Carl Zaiss). The cross-sections of the film were taken in a direction parallel to the normal direction of the film surface. Next, the target substance was analyzed at the five locations using Energy Dispersive X-ray Spectroscopy (EDS) (product name: X-Flash4010, manufactured by Bruker AXS), and the content per unit area was calculated. Finally, the content of the target substance contained in the film according to this embodiment was calculated from the average value of the five locations, and this value was taken as the content (area %) of the target substance contained in the film.

[0090] <Solar reflectance evaluation> The solar reflectance evaluation is described below. Solar reflectance was calculated by first measuring the reflectance using a spectrophotometer (U-4000, Hitachi High-Tech) and then converting it to solar reflectance.

[0091] The reflectance was measured by incident light with wavelengths ranging from 300 nm to 2500 nm. Next, the measured reflectance was multiplied by a weighting value (weighting coefficient) based on JIS-K560 (Method for determining the solar reflectance of coating films), and the integral was calculated to determine the solar reflectance from the integrated value.

[0092] For the measurement sample, a 50mm x 70mm square polycarbonate resin sheet with a thickness of 1mm was used, on which the film of the present invention was formed. The film was applied to the polycarbonate resin sheet using a spin coater to the desired thickness and then baked.

[0093] In terms of solar reflectance, a solar reflectance of 60% or more indicates a high temperature reduction effect and can be considered a very good film. Furthermore, a solar reflectance of 50% to less than 60% indicates a relatively high temperature reduction effect and can be considered a good film. A solar reflectance of less than 50% indicates a temperature reduction effect, but it is not high.

[0094] (Two-tiered rating: A / B) A: Solar reflectance of 60% or more B: Solar reflectance is 50% or more but less than 60% C: Although the solar reflectance was less than 50%, it was an improvement over Comparative Example 1.

[0095] <Heat shielding effect> Figure 3 is a schematic diagram showing the temperature evaluation method. As shown in Figure 3, a lamp 22, a temperature measuring jig 25, and a test piece 23 for temperature evaluation were used for temperature measurement. For the test piece 23 for temperature evaluation, a film of the present invention was formed on a polycarbonate resin sheet measuring 50 mm x 70 mm and 1 mm thick. The film was applied to this polycarbonate resin sheet using a spin coater to the desired film thickness and then fired. For the temperature measuring jig 25, a 120 mm x 120 mm x 120 mm corrugated cardboard sheet with a self-colored surface was used, and a 40 mm x 40 mm window was provided in the mounting area for the test piece 23 for temperature evaluation. A Hilux MT150FD6500K (Iwasaki Electric) lamp 22 was used.

[0096] Next, a test piece 23 for temperature evaluation was attached to the temperature measuring jig 25, and a thermocouple was attached to the back surface of the test piece 23. The temperature measuring jig 25 with the test piece 23 attached was positioned so that the distance to the lamp 22 was 100 mm. Then, the lamp 22 was irradiated for 60 minutes, and the temperature was measured after 60 minutes.

[0097] The temperature reduction effect was determined by forming a black blank on the surface of a test piece 23 for temperature evaluation, measuring the temperature, and calculating the difference between that and the temperature measurement result of the film in the example.

[0098] For the black blank, 20g of carbon black (MA100, Mitsubishi Chemical) was used. Furthermore, a paint mixture of 100g of epoxy resin (jER828; Mitsubishi Chemical), 70g of amine curing agent (STII, Mitsubishi Chemical), and 20g of thinner was applied to the surface of test piece 23 using a planetary rotating device, and then fired to produce the specimen.

[0099] A film can be considered to have very high heat-shielding properties if its temperature reduction effect is 7°C or more. A film can be considered to have relatively high heat-shielding properties if its temperature reduction effect is between 3°C and 7°C.

[0100] (3-level rating from A to C) A: Temperature reduction effect of 7°C or more B: Temperature reduction effect is 3°C or more but less than 7°C C: Although the temperature reduction effect was less than 3°C, it was an improvement over Comparative Example 1.

[0101] <Evaluation of film antifouling properties> The glossiness of the film was measured using a gloss meter to evaluate its antifouling properties. For the measurement sample, a 50mm x 70mm square polycarbonate resin sheet with a thickness of 1mm was used, on which the film of the present invention was formed. This polycarbonate resin sheet was coated to the desired thickness using a spin coater and then fired. After firing, the glossiness value of the film of the present invention was measured using a gloss meter. Next, fingerprints were left on the sample with bare hands, and then the glossiness value of the film of the present invention was measured. Glossiness change Δ = Glossiness after fingerprint application - Glossiness before fingerprint application If the gloss change Δ is less than 0.5, the film can be said to have good stain resistance with very little change in gloss. If the brightness change is between 0.5 and less than 1.0, the film can be said to have good stain resistance. If the brightness change is 1.0 or more, the film does not have no stain resistance, but it has little.

[0102] (Rated on a 4-point scale from A to C) A; Glossiness change ±0.5 is less than 0.5 B; Glossiness change ±0.5 or more and less than 1.0 C; Glossiness change ±1.0 or greater

[0103] <Creation of the third particle> 125g of resin (Olestar Q-691, manufactured by Mitsui Chemicals, Inc.), 6.5g of dispersant, 32g of titanium dioxide (D-970, manufactured by Sakai Chemicals, Inc., average particle size 0.26μm, silica surface coating), and 90g of thinner were weighed and stirred in a ball mill for 15 hours to obtain white paint 1.

[0104] Similarly, white paints 2, 3, 4, and 5 were obtained by varying the amount of titanium dioxide to 41g, 84g, 188g, and 400g.

[0105] Each of the obtained white paints was used as the main component. 1 g of hardener (Takenate D-120N, manufactured by Mitsui Chemicals, Inc.) was mixed with 10 g of the main component, and the mixture was cured to obtain a cured product.

[0106] Each of the resulting hardened materials was pulverized using a mechanical rotary pulverizer, and then classified to obtain particles of the desired particle size, thereby producing a third type of particle.

[0107] [Example 1] In Example 1, the paint was prepared by the following method. 125g of resin, 0.5g of azo organic particles, and 145g of titanium dioxide (an amount that accounts for 23% of the surface area in the film) were weighed out. In addition, a third particle 1 (6% titanium dioxide content in the base material, 20% surface area content in the film, average particle size 20μm), 5g of silica, 5g of dispersant, and 100g of solvent were weighed out and stirred in a ball mill for 15 hours to obtain the main component. 1g of hardener was mixed with 10g of the obtained main component to obtain the paint of Example 1.

[0108] For the resin, we used Olestar Q-691 (manufactured by Mitsui Chemicals, Inc.). For the azo organic particles, we used Chromofine Black A1103 (manufactured by Dainichi Seika Kogyo Co., Ltd.). For the titanium dioxide, we used D-970 (manufactured by Sakai Chemical Co., Ltd., average particle size 0.26 μm, silica surface coating). For the silica, we used ACEMATT-OK607. For the curing agent, we used Takenate D-120N (manufactured by Mitsui Chemicals, Inc.).

[0109] <Membrane fabrication> In Example 1, the film was prepared by the following method. The above-mentioned paint was applied to a polycarbonate plate using a spin coater to create a film of the present invention with a thickness of 30 μm. After drying overnight at room temperature, it was baked at 110°C for 30 minutes to obtain the film of Example 1.

[0110] [Examples 2-7] In Example 2, a third particle was prepared using white paint 2; in Example 3, a third particle was prepared using white paint 3; and in Example 4, a third particle was prepared using white pigment 4. The paint and film were prepared in the same manner as in Example 1, except that the conditions were as described in Table 1. In Examples 5-7, a third particle was prepared using white paint 1, and the paint and film were prepared in the same manner as in Example 1, except that the conditions were as described in Table 1.

[0111] [Example 8] In Example 8, commercially available acrylic polymer particles (manufactured by Dainichi Seika Co., Ltd., product name: Lovecolor 010(F) White, average particle size 20 μm, titanium dioxide content in base material 23%) were used as the third particle. Otherwise, the paint and film were prepared in the same manner as in Example 1 under the conditions described in Table 1.

[0112] [Examples 9-11] In Example 9, large-particle-sized white particles were prepared using white paint 5; in Example 10, using white paint 3; and in Example 11, using white paint 4. The paints and films were prepared in the same manner as in Example 1, except that the conditions were as described in Table 1.

[0113] [Comparative Examples 1 and 2] In Comparative Examples 1 and 2, instead of the third particle, resin particles were used that were obtained by adding 1 g of curing agent (Takenate D-120N, Mitsui Chemicals) to 10 g of resin (Olestar Q-691, Mitsui Chemicals) and then crushing and classifying the resulting cured product. Otherwise, the paint and film were prepared in the same manner as in Example 1.

[0114] [Table 1]

[0115] [Table 2]

[0116] <Evaluation Results> The evaluation results are shown in Tables 1 and 2.

[0117] The film of Example 1 had a solar reflectance of 60% or more, a temperature reduction effect (heat shielding effect) of 7°C or more, which was very good, and stain resistance (change in gloss) was less than ±0.5, which was also very good. Example 1 was obtained by changing the content of the second particle in the base material of the third particle to 15%. 3 In this case, the solar reflectance, heat shielding effect, and stain resistance were all very good. Example 4 Compared to Example 1, the content of the second particle in the base material of the third particle is changed to 28%, and the content of the first particle in the film is changed to 30%. 4 The film exhibited good heat shielding effect between 3°C and 7°C, and very good solar reflectance and stain resistance (glossiness change). This is an example in which the average particle size of the third particle was changed to 5 μm compared to Example 1. 5 The stain resistance was good, with a ± of 0.5 or more and less than 1.0, and the solar reflectance and heat shielding effect were very good. Example 1: The average particle size of the third particle was changed to 30 μm. 6 The heat shielding effect was good between 3°C and 7°C, and the solar reflectance and stain resistance (change in gloss) were very good. Example 1: The average particle size of the first particle was changed to 3 μm. 7 The solar reflectance, heat shielding effect, and stain resistance were very good. Example 1: The third particle was replaced with commercially available acrylic polymer particles. 8 The heat shielding effect was good, ranging from 3°C to less than 7°C, and the solar reflectance and stain resistance (change in gloss) were very good. Example 9 showed very good stain resistance and a good solar reflectance of 50% to less than 60%, but although the heat shielding effect was improved compared to Comparative Example 1, the temperature reduction effect was less than 3°C. Example 3 In contrast, Example 10, in which the average particle size of the third particle was changed to 3 μm, showed very good solar reflectance and heat shielding effect, but the stain resistance was poor, with a gloss change of ±1.0 or more, indicating that the stain resistance effect was inferior to Example 10. 3The amount was less compared to Example 1. In Example 11, the content of the second particle in the base material of the third particle was changed to 28%, and the content of the first particle in the film was changed to 10% compared to Example 1. The film of Example 11 had very good stain resistance, but the solar reflectance was less than 50%, and the heat shielding effect was a temperature reduction of less than 3°C. However, both the solar reflectance and heat shielding effect were improved compared to Comparative Example 1.

[0118] Comparative Example 1, in which the third particle was replaced with a resin particle that did not contain the second particle compared to Example 1, showed very good stain resistance, but poor solar reflectance and heat shielding effect. In Comparative Example 2, in which the third particle was replaced with a resin particle that did not contain the second particle compared to Example 2, the stain resistance was also very good, but poor solar reflectance and heat shielding effect. [Industrial applicability]

[0119] The film formed on the upper surface of the optical equipment of the present invention can be used on the lens barrels of optical equipment such as cameras, video cameras, and broadcasting equipment, as well as on camera bodies, video cameras, surveillance cameras, weather cameras, and other devices that may be used outdoors.

Claims

1. An article comprising a base material and a film provided on the base material having an uneven surface structure, The film comprises at least a resin, a first particle, and a third particle in which a second particle is encased in a base material. The first particles and the second particles are a mixture of one or more materials selected from titanium dioxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, and aluminum oxide. The average particle size of the first particle is 10 nm or more and 5 μm or less. The content (area %) of the first particles in the resin is 10 area % or more and 80 area % or less. The content (area %) of the second particles in the base material is 5 area % or more, and is less than or equal to the content (area %) of the first particles in the resin. An article characterized in that the average particle diameter of the third particle is greater than the average particle diameter of the first particle and the average particle diameter of the second particle.

2. The article according to claim 1, wherein the content of the third particles in the resin is 5 area percent or more when the resin is considered as 100 area percent.

3. The article according to claim 1 or 2, wherein the content of the resin is 60 area percent or less when the film is considered as 100 area percent.

4. The article according to any one of claims 1 to 3, characterized in that the first particle and the second particle have rutile-type titanium dioxide as their main component.

5. The article according to any one of claims 1 to 4, characterized in that the resin is an acrylic resin.

6. The article according to any one of claims 1 to 5, characterized in that the base material is acrylic resin.

7. The article according to any one of claims 1 to 6, characterized in that the second particle has an average particle diameter of 10 nm or more and 5 μm or less.

8. The article according to any one of claims 1 to 7, characterized in that the average particle diameter of the third particle is 5 μm or more and 50 μm or less.

9. The article according to any one of claims 1 to 8, characterized in that the film further comprises silica particles.

10. The article according to any one of claims 1 to 9, characterized in that the substrate includes a primer.

11. The article according to any one of claims 1 to 10, characterized in that the substrate on which the film is formed is the outer cylinder of a lens barrel.

12. The article according to any one of claims 1 to 10, characterized in that electronic equipment is housed inside the substrate on which the film is formed.

13. A coating that forms a film having an uneven surface structure, It comprises at least a resin, a first particle, and a third particle in which the second particle is encased in a base material, The first particles and the second particles are a mixture of one or more materials selected from titanium dioxide, barium sulfate, zinc oxide, zinc sulfide, zinc sulfate, barium sulfate, calcium carbonate, and aluminum oxide. The average particle size of the first particle is 10 nm or more and 5 μm or less. The content of the first particles in the resin is 20% by mass or more and 55% by mass or less. The content of the second particles in the base material is 15% by mass or more, and is less than or equal to the content of the first particles in the resin. A paint characterized in that the average particle diameter of the third particle is larger than the average particle diameter of the first particle and the average particle diameter of the second particle.

14. The paint according to claim 13, characterized in that the content of the third particles in the resin is 0.5% by mass or more, when the non-volatile components in the paint are taken as 100% by mass.

15. The paint according to claim 13 or 14, wherein the content of the resin is 50% by mass or less when the non-volatile components in the paint are taken as 100% by mass.

16. The paint according to any one of claims 13 to 15, characterized in that the first particle and the second particle have rutile-type titanium dioxide as their main component.

17. The paint according to any one of claims 13 to 16, characterized in that the resin is an acrylic resin.

18. The paint according to any one of claims 13 to 17, characterized in that the base material is acrylic resin.

19. The paint according to any one of claims 13 to 18, characterized in that the second particle has an average particle diameter of 10 nm or more and 5 μm or less.

20. The paint according to any one of claims 13 to 19, characterized in that the average particle diameter of the third particle is greater than or equal to 5 μm and less than or equal to 50 μm.

21. The paint according to any one of claims 13 to 20, further characterized in that the paint contains silica particles.

22. A method for manufacturing an article, characterized by applying a paint according to any one of claims 13 to 21 onto a substrate to manufacture the article.

Images