Absorption heat shielding film, absorption heat shielding member, article, method for manufacturing absorption heat shielding film, and method for manufacturing heat shielding member

Abstract

To provide an absorption heat shielding film that achieves both absorption heat shielding properties (visible light absorption properties and heat shielding properties) and wear resistance.SOLUTION: An absorption heat shielding film includes a metal layer including a first rugged structure on one principal surface, a metal oxide layer provided on the one principal surface, and a coating layer provided on the metal oxide layer and different in material from the metal oxide layer. The first rugged structure has an arithmetic average roughness Ra of 1 nm or more and 50 nm or less. The first rugged structure has a maximum height Rz of 100 nm or more and 800 nm or less.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a light-absorbing and heat-shielding film, a light-absorbing and heat-shielding member, an article, a method for manufacturing a light-absorbing and heat-shielding film, and a method for manufacturing a light-absorbing and heat-shielding member. [Background technology]

[0002] In recent years, the use of heat-shielding materials that suppress temperature rise has been expanding in the interior and exterior parts of optical equipment, space equipment, and transportation equipment. In addition, when heat-shielding materials are used inside the lens barrel of an infrared camera or in aperture films, they can reduce noise caused by stray light, and are less likely to increase in temperature and have high dimensional stability, so materials that have both light-absorbing and heat-shielding properties are required. Depending on the application, these materials are also required to have not only light-absorbing and heat-shielding properties but also wear resistance. A light-absorbing and heat-shielding film with excellent light-absorbing and heat-shielding properties that absorbs visible light and near-infrared rays and has low far-infrared radiation has been proposed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 019264 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even with the member disclosed in Patent Document 1, there is still room for further study in order to achieve both light absorbing and heat shielding properties and wear resistance. The present invention has been made in consideration of the above-mentioned studies, and one of its objects is to provide a light-absorbing and heat-shielding film that achieves both light-absorbing and heat-shielding properties (visible light absorption and heat-shielding properties) and abrasion resistance by using a surface coating protective material as a surface treatment agent. [Means for solving the problem]

[0005] The present invention provides a semiconductor device comprising: a metal layer having a main surface including a first uneven structure; a metal oxide layer provided on the main surface; a coating layer formed on the metal oxide layer and made of a material different from that of the metal oxide layer; Including, The light absorbing and heat shielding film has an arithmetic mean roughness Ra of the first uneven structure of 1 nm or more and 50 nm or less, and a maximum height Rz of the first uneven structure of 100 nm or more and 800 nm or less. The present invention also provides a light absorbing and heat shielding member comprising the above light absorbing and heat shielding film, and a substrate provided on the surface opposite to the surface having the first uneven structure. The present invention also relates to an article comprising the above light-absorbing and heat-shielding film. The present invention also provides a method for manufacturing a mold having a concave-convex shape, comprising the steps of: forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; forming a coating layer on the relief structure of the metal layer after the separating step; The method for producing a light absorbing and heat shielding film includes the steps of: The present invention also provides a method for manufacturing a mold having a concave-convex shape, comprising the steps of: forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; forming a coating layer on the relief structure of the metal layer after the separating step; a step of adhering a substrate to a surface of the metal layer opposite to a surface onto which the concave-convex shape is transferred; The method for producing a light absorbing and heat shielding member includes the steps of: Effect of the Invention

[0006] According to the present invention, it is possible to provide a light absorbing and heat shielding film that has both light absorbing and heat shielding properties and abrasion resistance. By using an optical element made of a metal material having a microstructure and a coating protective layer on its surface, it is possible to achieve both light absorbing and heat shielding properties and abrasion resistance. [Brief description of the drawings]

[0007] [Figure 1A] 1 is a schematic cross-sectional view showing an embodiment of a light absorbing and heat shielding film of the present invention. [Figure 1B] 1 is a schematic cross-sectional view showing an embodiment of a light absorbing and heat shielding film of the present invention. [Figure 2A] 1 is a schematic cross-sectional view showing an embodiment of a light absorbing and heat shielding member of the present invention. [Figure 2B] 1 is a schematic cross-sectional view showing an embodiment of a light absorbing and heat shielding member of the present invention. [Figure 3A] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding film or a light absorbing and heat shielding member of the present invention. [Figure 3B] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding film or a light absorbing and heat shielding member of the present invention. [Figure 3C] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding film or a light absorbing and heat shielding member of the present invention. [Figure 3D] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 3E] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 3F] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 3G] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 3H] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 3I] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a light absorbing and heat shielding member of the present invention. [Figure 4] 2 is an optical microscope image of the surface of the light absorbing and heat shielding member obtained in Example 1. [Diagram 5] 2 is an optical microscope image of the surface of the light absorbing and heat shielding member obtained in Example 1. [Figure 6] 3 is an optical microscope image of the surface of the light absorbing and heat shielding member obtained in Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described in detail. [First embodiment] The first embodiment relates to a light absorbing and heat shielding film, a light absorbing and heat shielding member, and an article. The light absorbing and heat shielding film according to this embodiment includes a metal layer having a first uneven structure on one main surface thereof, a metal oxide layer provided on the one principal surface; a coating layer formed on the metal oxide layer and made of a material different from that of the metal oxide layer; Including, The first uneven structure has an arithmetic mean roughness Ra of 1 nm or more and 50 nm or less, and a maximum height Rz of the first uneven structure of 100 nm or more and 800 nm or less. The light absorbing and heat shielding member according to this embodiment includes the light absorbing and heat shielding film, and a substrate is provided on the surface opposite to the surface having the first uneven structure. The article according to this embodiment includes a light-absorbing and heat-shielding film. Each substance is described below.

[0009] <Light absorption heat shield film> The light-absorbing heat-shielding film of this embodiment will be described with reference to Fig. 1. As shown in Figs. 1A and 1B, one embodiment of the light-absorbing heat-shielding film of the present invention is a light-absorbing heat-shielding film 10 including a metal layer 1 having one main surface including a first uneven structure 22, metal oxide layers 3 and 4 provided on the one main surface, and a coating layer 40 provided on the metal oxide layers 3 and 4 and made of a different material from the metal oxide layers 3 and 4. The light-absorbing heat-shielding film 10 has a structure in which the metal oxide layers 3 and 4 are located between the light-absorbing heat-shielding film 10 and the coating layer 40. Note that if one of the metal oxide layer 3 and the metal oxide layer 4 is present, the other of the metal oxide layer 3 and the metal oxide layer 4 may not be present, and Fig. 1A is an example in which the metal oxide layer 4 is not present.

[0010] (metal layer) The light absorbing and heat shielding film 10 of the present invention includes a metal layer 1 having one main surface including a first uneven structure 22 . Metals with high electrical conductivity, such as aluminum and nickel, have low far-infrared radiation and heat shielding properties, but do not exhibit light absorption. On the other hand, a fine uneven structure with a subwavelength structure smaller than the wavelength of visible light is known to have an anti-reflection effect, and it is known that the anti-reflection effect exhibits excellent wavelength band characteristics and incident angle characteristics by continuously changing the spatial occupancy rate of the structure. Therefore, when the metal surface is made finely uneven, reflection on the metal surface is suppressed in a wide wavelength range of visible light, the reflectance in the entire visible light range is reduced, the metal surface appears black, and light absorption properties are expressed. Therefore, it is considered that a metal member having a fine uneven surface can have both light absorption and heat shielding properties.

[0011] In this specification, the first uneven structure 22 and the second uneven structure 21 are collectively referred to as the fine uneven structure 2, or the fine uneven structure 2, or the uneven structure 2. The light absorbing and heat shielding film 10 has a base 11 below the fine uneven structure 2, and this base 11 is a part of the metal layer 1. It is preferable that the metal layer 1 contains any one selected from the group consisting of nickel, chromium, and zinc. The material of the base 11 in the metal layer 1 is preferably a metal with high conductivity, such as silver, copper, gold, aluminum, magnesium, tungsten, cobalt, zinc, nickel, and chromium, and nickel, zinc, and chromium are preferable, and nickel is particularly preferable. The fine uneven structure 2 provided on the surface of the metal layer 1 is also preferably made of the above-mentioned metal with high conductivity, and more preferably made of the same metal as the base 11 of the metal layer 1.

[0012] The metal layer 1 includes a base 11 and a fine concave-convex structure 2 provided on the base 11. The base 11 is a portion where the metal layer 1 is continuous in the extension direction of the light absorbing and heat shielding film 10 (the horizontal direction in Figs. 1A to 1D), and the fine concave-convex structure 2 is a portion where the metal layer 1 is discontinuous in the extension direction of the light absorbing and heat shielding film 10 (the horizontal direction in Figs. 1A to 1D). In Fig. 1, the boundary between the base 11 and the fine concave-convex structure 2 is indicated by a dashed line.

[0013] The fine concave-convex structure portion 2 is a portion having a fine concave-convex structure provided on one surface of the metal layer 1, and the fine concave-convex structure portion 2 has a hierarchical structure. That is, the fine concave-convex structure portion 2 has a first concave-convex structure 22 and a second concave-convex structure 21. An object having the fine concave-convex structure portion 2 is a fine concave-convex structure, and the fine concave-convex structure portion 2 is a part or the whole of the fine concave-convex structure, so the fine concave-convex structure portion 2 can also be called a fine concave-convex structure.

[0014] The second uneven structure 21 includes a plurality of convex portions (e.g., convex portion 211 and convex portion 212). The second uneven structure 21 also includes a plurality of concave portions (e.g., concave portion 210 between convex portions 211 and 212). Due to the presence of the second uneven structure 21, the light absorbing and heat shielding film 10 has the effect of suppressing reflection of surrounding light sources. Note that the convex portions 211 and 212 of the second uneven structure 21 are part of the metal layer 1, and the concave portion 210 of the second uneven structure 21 does not necessarily need to have the metal layer 1, and is a space in which a substance other than the metal layer 1 may be present.

[0015] The first uneven structure 22 includes a plurality of convex portions (e.g., convex portion 221 and convex portion 222). The first uneven structure 22 also includes a plurality of concave portions (e.g., concave portion 220 between convex portions 221 and 222). Due to the presence of the first uneven structure 22, the light absorbing heat shielding film 10 has a reduced reflectance over the entire visible light range, and has a light absorbing effect. The convex portions 221 and 222 of the first uneven structure 22 are part of the metal layer 1, and the concave portion 220 of the first uneven structure 22 does not necessarily need to have the metal layer 1, and is a space in which a substance other than the metal layer 1 may be present.

[0016] It is preferable that the first uneven structure 22 is formed on the upper surface of the second uneven structure 21. In this way, the light absorbing heat shielding film 10 has an enhanced light absorbing effect. In other words, the first uneven structure 22 is provided on the upper surface of each of a plurality of convex portions (e.g., convex portions 211 and 212) included in the second uneven structure 21. It is preferable that the main component of the metal material of the second uneven structure 21 and the first uneven structure 22 is the same.

[0017] The metal layer 1, which is a concave-convex structure in the light absorbing heat shielding film 10, has a base 11 made of a metal material having the same main component as the second concave-convex structure 21 and the first concave-convex structure 22 under the second concave-convex structure 21. The base 11 extends continuously under a plurality of convex portions (e.g., convex portions 211 and 212) included in the second concave-convex structure 21. In contrast, the fine concave-convex structure portion 2 is discontinuous in the metal layer 1 due to the concave portions (e.g., concave portions 210) of the second concave-convex structure 21 or the concave portions 220 of the first concave-convex structure 22. That is, the convex portions (e.g., convex portions 211 and 212) of the second concave-convex structure 21 are discontinuous due to the concave portions 210. Also, the convex portions (e.g., convex portions 221 and 222) of the first concave-convex structure 22 are discontinuous due to the concave portions 220.

[0018] Moreover, it is preferable that the main components of the metal materials of the base 11, the first uneven structure 22, and the second uneven structure 21 are the same. By forming the base 11, the first uneven structure 22, and the second uneven structure 21 from a common metal material (i.e., a single metal layer 1), it is possible to achieve superior light absorption and heat shielding properties compared to forming them from different metal materials (i.e., multiple metal layers). The arithmetic mean roughness Ra of the first uneven structure 22 is preferably 1 nm or more and 50 nm or less, and the arithmetic mean roughness Ra of the second uneven structure 21 is preferably 0.1 μm or more and 5 μm or less. In this way, the first uneven structure 22 reduces the reflectance in the entire visible light range, and has a light absorbing effect. The second uneven structure 21 allows the light absorbing heat shielding film 10 to suppress reflections of surrounding light sources.

[0019] Here, the average roughness of the fine concave-convex structure 2, or the average roughness of the fine concave-convex structure 2 to which a transparent metal oxide described later is attached, refers to the arithmetic average roughness specified in "Definition and display of surface roughness" of JIS B 0601. When only a reference length is extracted from the roughness curve in the direction of the average line, the X-axis is taken in the direction of the average line of the extracted portion, and the Y-axis is taken in the direction of the longitudinal magnification, and the roughness curve is expressed as y = f(x), the following formula (1) can be used to determine the average roughness.

[0020]

number

[0021] Furthermore, in the light absorbing heat shielding film 10 according to this embodiment, the maximum height Rz of the first uneven structure 22 on the surface of the metal layer 1 is preferably 100 nm or more and 800 nm or less, and the maximum height Rz of the second uneven structure 21 is preferably 1 μm or more and 10 μm or less. In this way, the first uneven structure 22 reduces the reflectance in the entire visible light range, and has a light absorbing effect. The second uneven structure 21 allows the light absorbing heat shielding film 10 to suppress the reflection of surrounding light sources.

[0022] Here, the maximum height of the fine concave-convex structure 2, or the maximum height of the fine concave-convex structure 2 to which a transparent metal oxide described later is attached, refers to the maximum height specified in "Definition and display of surface roughness" of JIS B 0601. A reference length is cut out from the roughness curve in the direction of the average line, and the distance between the peak line and the valley line of the cut-out portion is measured in the direction of the longitudinal magnification of the roughness curve and calculated. This valley line may correspond to the boundary between the base 11 and the fine concave-convex structure 2, shown by the dashed line in FIG. 1.

[0023] The arithmetic mean roughness Ra and maximum height Rz of the fine concave-convex structure 2 can be determined by observing the cross section of the light absorbing and heat shielding film 10 of this embodiment with a scanning electron microscope or the like.

[0024] (Metal oxide layer) The light absorbing and heat shielding film of the present invention includes metal oxide layers 3 and 4 provided on one main surface of a metal layer 1. The metal oxide layer 4 is not essential. It is preferable that a transparent metal oxide layer 3 is attached to the surface of the fine concave-convex structure 2. In other words, it is preferable that the light absorbing and heat shielding film 10 includes a transparent metal oxide layer 3 on the surface of the fine concave-convex structure, which is the metal layer 1. It is preferable that the metal oxide layer 3 is provided at least on the convex parts (e.g., the convex parts 221 and 222), and it is more preferable that it is provided on the entire surface of the fine concave-convex structure. It is preferable that the metal component of the metal oxide layer 3 attached to the surface of the fine concave-convex structure 2 is different from the metal component of the metal layer 1. That is, for example, if the material of the metal layer 1 is mainly nickel, the metal oxide layer 3 attached to the surface of the fine concave-convex structure 2 is mainly an oxide of a metal other than nickel. Therefore, the metal oxide layer 3 attached to the surface of the fine concave-convex structure 2 can be distinguished from a metal oxide having the same metal component as the metal component of the metal layer 1, which is formed by natural oxidation of the metal layer 1, etc.

[0025] In this specification, the metal oxide layers 3 and 4 may be referred to as metal oxide. The metal oxide layer 3 is provided between a plurality of convex portions (for example, the convex portions 221 and 222) included in the first concave-convex structure 22. That is, the metal oxide layer 3 is preferably formed in a film shape so as to fill the concave portions (for example, the concave portions 220 between the convex portions 221 and 222) of the first concave-convex structure 22 and cover the convex portions (for example, the convex portions 221 and 222) of the first concave-convex structure 22. A metal oxide layer 4 covering the metal oxide layer 3 may be further provided on the metal oxide layer 3 covering the concave and convex portions of the first concave-convex structure 22. The metal oxide layer 4 is provided so as to cover a plurality of convex portions (for example, the convex portions 211 and 212) included in the second concave-convex structure 21. The metal oxide layer 4 is also provided in the concave portions (for example, the concave portions 210 between the convex portions 211 and 212) included in the second concave-convex structure 21. That is, the metal oxide layer 4 is provided between a plurality of convex portions (e.g., convex portions 211 and 212) included in the second concave-convex structure 21. In this manner, the metal oxide layer 4 is preferably formed in a film shape so as to fill in the concave portions (e.g., concave portions 210 between convex portions 211 and 212) of the second concave-convex structure 21 and cover the convex portions (e.g., convex portions 211 and 212) of the second concave-convex structure 21.

[0026] 1B, the light absorbing and heat shielding film of the present invention may further include a transparent metal oxide layer 4 that covers the surface of the metal oxide layer 3 that is not in contact with the microrelief structure 2. It is preferable that the metal oxide layer 4 covers the microrelief structure 2, and that the metal oxide layer 3 is provided between the metal oxide layer 4 and the metal layer 1.

[0027] The material of the metal oxide layer 3 is not particularly limited, but it is preferable that the main component is aluminum oxide, and more preferable that the metal oxide layer 3 contains plate-shaped crystals (hereinafter referred to as plate-shaped crystals) mainly composed of aluminum oxide. The plate-shaped crystals mainly composed of aluminum oxide are formed of crystals mainly composed of aluminum oxide or hydroxide or hydrates thereof, and boehmite is a particularly preferable crystal. Here, the plate-shaped crystals mainly composed of aluminum oxide may be plate-shaped crystals made of aluminum oxide alone, or may be plate-shaped crystals containing aluminum oxide plate-shaped crystals and trace amounts of zirconium, silicon, titanium, zinc, etc.

[0028] In this way, the light absorbing and heat shielding film can protect the fine concave-convex structure 2 by providing the metal oxide layer 3. When the metal oxide layer 3 is a plate-like structure of plate crystals mainly composed of aluminum oxide, it is preferable that the plate crystals mainly composed of aluminum oxide are arranged in a direction perpendicular to the surface direction of the metal layer 1, and that their spatial occupancy rate changes continuously.

[0029] The material of the metal oxide layer 4 is not particularly limited, but preferably contains an amorphous gel of aluminum oxide. The metal oxide layer 4 increases the hardness of the surface of the light absorbing heat shielding film 10 of this embodiment while decreasing the light absorption. Therefore, the thickness of the metal oxide layer 4 may be appropriately determined so as to satisfy the required hardness and light absorption. The metal component (metal element bonded to oxygen) of the metal oxide layer 3 and the metal component (metal element bonded to oxygen) of the metal oxide layer 4 may be different from each other, but typically they can be the same. For example, the metal component of the metal oxide layer 3 and the metal component of the metal oxide layer 4 can both be aluminum. The crystallinity of the metal oxide layer 3 and the crystallinity of the metal oxide layer 4 may be the same, but typically they can be different from each other. For example, the crystallinity of the metal oxide layer 3 can be crystalline, and the crystallinity of the metal oxide layer 4 can be amorphous. The composition ratio of metal to oxygen in the metal oxide layer 3 and the composition ratio of metal to oxygen in the metal oxide layer 4 may be the same, but typically they can be different from each other. For example, of metal oxide layer 3 and metal oxide layer 4, both of which are aluminum oxide, metal oxide layer 3 may be closer to the stoichiometric composition (Al2O3). The impurities in metal oxide layer 3 and metal oxide layer 4 may be different from each other. In this way, metal oxide layer 3 and metal oxide layer 4 can be distinguished from each other by the metal components, crystallinity, composition ratio, impurities, etc.

[0030] (covering layer) The light absorbing and heat shielding film 10 of the present invention includes a coating layer 40 provided on the metal oxide layers 3 and 4 and made of a material different from that of the metal oxide layers 3 and 4. The metal oxide layer 4 may not be required. As the coating layer 40 that is in contact with the metal oxide layers 3 and 4 and made of a material different from that of the metal oxide layers 3 and 4, the coating layer 40 preferably contains Si and O, more preferably contains siloxane, and further preferably contains silsesquioxane. In addition to having the coating layer 40 made of the inorganic material described above, the light absorbing and heat shielding film 10 of the present invention preferably further includes a coating layer 40 made of an organic material. As an organic material, the coating layer 40 preferably contains a fluororesin or an acrylic resin. The material of the metal oxide layers 3 and 4 is, as described above, for example, aluminum oxide. The coating layer 40 being made of a different material from the metal oxide layers 3, 4 means that the materials are different in that, for example, the metal oxide layers 3, 4 mainly contain Al (aluminum), whereas the coating layer 40 mainly contains Si (silicon) in the inorganic material and mainly contains C (carbon) in the organic material. In this case, it is not that the coating layer 40 does not contain any Al, but rather that when the material of the metal oxide layers 3, 4 is mainly Al, the material of the coating layer 40 is not mainly composed of Al. In this way, it is possible to provide the light absorbing heat shielding film 10 with abrasion resistance and weather resistance.

[0031] Silsesquioxane has the formula [R(SiO 1.5 ) n ] (R1 is a functional group and is, for example, at least one selected from the group consisting of a polymerizable group, a hydroxyl group, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms), and is a hybrid material of silicon oxide and an organic substance.

[0032] Silsesquioxane (hereinafter sometimes abbreviated as SQ) is a siloxane-based compound whose main chain structure consists of Si-O bonds, [R1(SiO 1.5 ) nIn this case, R1 is preferably a polymerizable group, and more preferably at least one polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an oxetanyl group, and an epoxy group. By doing so, it is possible to impart excellent abrasion resistance to the light absorbing and heat shielding film 10.

[0033] When silsesquioxane plays a role of binding particles composed of a large number of solid substances, it is possible to realize a superior film strength while maintaining a high porosity. The silsesquioxane is not particularly limited in the form of a polymer, and examples thereof include known linear polysiloxanes, cage polysiloxanes, and ladder polysiloxanes. The structure of silsesquioxane is a structure in which each silicon atom is bonded to three oxygen atoms, and each oxygen atom is bonded to two silicon atoms (the number of oxygen atoms relative to the number of silicon atoms is 1.5). From the viewpoint of cost, linear polysiloxanes, cage polysiloxanes, and ladder polysiloxanes may be mixed. The preferred film thickness of the silsesquioxane layer is 20 nm or more and 180 nm or less, preferably 30 nm or more and 150 nm or less.

[0034] The silsesquioxane is preferably a compound having a polymerizable group (R1 in the above formula) in the molecule and curing by radical polymerization or cationic polymerization. The R1 is preferably at least one polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an oxetanyl group, and an epoxy group. In the silsesquioxane curing by radical polymerization, the R1 may be an acryloyl group or a methacryloyl group. On the other hand, in the type curing by cationic polymerization, the R1 may be an oxetanyl group or an epoxy group. Specifically, the silsesquioxane derivative SQ series (AC-SQ, MAC-SQ, OX-SQ) manufactured by Toa Gosei Co., Ltd. may be mentioned.

[0035] As described above, the light absorbing and heat shielding film 10 of the present invention preferably has a coating layer 40 made of an organic material in addition to having an inorganic coating layer 40 (e.g., a silsesquioxane layer). Examples of materials used for the organic coating layer 40 include fluororesin and acrylic resin. The organic coating layer 40 is preferably formed on the inorganic coating layer 40 (e.g., a silsesquioxane layer) described above. In this way, weather resistance can be imparted to the light absorbing and heat shielding film 10.

[0036] The coating layer 40 preferably contains a fluoroolefin copolymer (fluoroolefin polymer) as a fluororesin. The fluoroolefin copolymer is a copolymer of a fluoroolefin and another copolymerizable monomer that can be copolymerized with the fluoroolefin. Examples of the fluoroolefin constituting the fluoroolefin copolymer include fluoroolefins having 2 to 3 carbon atoms, such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride. The ratio of the polymerization unit based on the fluoroolefin in the fluoroolefin copolymer is preferably 20 to 70 mol % in order to provide the coating film with sufficient weather resistance. As the other copolymerizable monomer constituting the fluoroolefin copolymer, a vinyl monomer, that is, a compound having a carbon-carbon double bond, is preferable. Examples of the vinyl monomer include vinyl ether, allyl ether, vinyl carboxylate, allyl carboxylate, and olefin. As the acrylic resin, a known one can be used.

[0037] The coating layer 40 may contain an acrylic resin. The acrylic resin is a resin containing a (meth)acrylic polymer. The content of the (meth)acrylic polymer in the acrylic resin is usually 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. The (meth)acrylic polymer has excellent optical properties such as high light transmittance and low wavelength dependency of the refractive index. The (meth)acrylic polymer is a polymer having a structural unit ((meth)acrylic acid ester unit) derived from a (meth)acrylic acid ester monomer. The content of the (meth)acrylic acid ester unit in the (meth)acrylic polymer is usually preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and particularly preferably 70% by mass or more.

[0038] The (meth)acrylic polymer may have a structural unit other than the (meth)acrylic acid ester unit. Such a structural unit is, for example, a structural unit derived from each monomer of styrene, vinyltoluene, α-methylstyrene, α-hydroxymethylstyrene, α-hydroxyethylstyrene, acrylonitrile, methacrylonitrile, ethylene, propylene, 4-methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene, methyl vinyl ketone, N-vinylpyrrolidone, and N-vinylcarbazole. The (meth)acrylic polymer may have two or more of these structural units. The organic material used for the coating layer 40 is not limited to fluororesin or acrylic resin, and any material having transparency and weather resistance may be used.

[0039] (others) The aluminum element, silicon element, and the like in the fine uneven structure 2, the metal oxide layer 3, and the metal oxide layer 4 can be detected by surface measurement using a scanning electron microscope (SEM) or a transmission electron microscope (TEM). They can also be detected by energy dispersive X-ray analysis (EDX) or X-ray photoelectron spectroscopy (XPS) during cross-sectional observation. Similarly, metal elements such as silver, copper, gold, aluminum, magnesium, tungsten, cobalt, zinc, nickel, and chromium in the metal layer 1 can be detected by surface measurement using a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0040] Similarly, silicon element, fluorine element, etc. in the coating layer 40 can be detected by surface measurement using a scanning electron microscope (SEM) or a transmission electron microscope (TEM). They can also be detected by energy dispersive X-ray analysis (EDX) or X-ray photoelectron spectroscopy (XPS) during cross-sectional observation. When the fine concave-convex structure 2, the metal oxide layer 3, or the metal oxide layer 4 is provided, the proportion of metal oxides such as aluminum element is relatively low from the surface (metal oxide layer 4) to the inside (metal layer 1) in the direction perpendicular to the surface direction of the metal layer 1. Conversely, the proportion of metal elements constituting the metal layer 1 and the fine concave-convex structure 2 is relatively high from the surface (metal oxide layer 4) to the inside (metal layer 1), and finally only metal elements are detected.

[0041] <Light absorbing and heat shielding material> 2A, an embodiment of the light absorbing and heat shielding member of the present invention is a light absorbing and heat shielding member 100 including the light absorbing and heat shielding film 10 of the present embodiment and a substrate 5 provided on the surface of the metal layer 1 of the light absorbing and heat shielding film 10 of the present embodiment opposite to the fine uneven structure portion 2 (first uneven structure 22). The light absorbing and heat shielding member 100 includes the substrate 5 and the light absorbing and heat shielding film 10 provided on the substrate 5. The shape of the substrate 5 may be any shape that can be formed according to the intended use, and may be, for example, a molded product, and examples of shapes include a flat plate shape, a film shape, a sheet shape, and the like, but are not limited thereto.

[0042] Materials for the substrate 5 include, but are not limited to, metal, glass, ceramics, wood, paper, and resin. Examples of resins include thermoplastic resins such as polyester, triacetyl cellulose, cellulose acetate, polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, and polymethyl methacrylate. Other examples of thermoplastic resins include ABS resin, polyphenylene oxide, polyurethane, polyethylene, and polyvinyl chloride. Other examples of thermosetting resins include unsaturated polyester resin, phenolic resin, crosslinked polyurethane, crosslinked acrylic resin, and crosslinked saturated polyester resin.

[0043] 2B , in another embodiment of the present invention, the light absorbing and heat shielding film 10 and the substrate 5 may be bonded by an adhesive layer 6. The adhesive layer 6 provided in the light absorbing and heat shielding member 100 may be any layer that can bond the light absorbing and heat shielding film 10 and the substrate 5, and examples thereof include a layer made of a cured product of an adhesive resin (e.g., epoxy resin, etc.), a double-sided tape, etc.

[0044] Although Figures 2A and 2B show a light absorbing and heat shielding member 100 having the light absorbing and heat shielding film 10 shown in Figure 1B, the light absorbing and heat shielding member 100 may have the light absorbing and heat shielding film 10 shown in Figure 2A or 2B instead of the light absorbing and heat shielding film 10 shown in Figure 1B.

[0045] <Examples of application of items> The article according to the present embodiment includes a heating element and a light-absorbing heat-shielding film 10. The light-absorbing heat-shielding film 10 of the present embodiment can be provided on the surface of various members or articles. The light-absorbing heat-shielding film 10 of the present embodiment is preferably used for a heating element having a heat generating means as a member or article. In an article including a heating element and a light-absorbing heat-shielding film 10, the light-absorbing heat-shielding film 10 insulates the heat of the heating element. Examples of articles including such a heating element include batteries, engines, motors, and vehicles. The engines include reciprocating engines, rotary engines, diesel engines, gas turbine engines, jet engines, and rocket engines. The motors include DC motors, AC motors, PM motors, brush motors, stepping motors, induction motors, servo motors, ultrasonic motors, in-wheel motors, and linear motors. A transport device including at least one of an engine and a motor may include the light-absorbing heat-shielding film 10. The transport device including at least one of an engine and a motor is not limited to various vehicles such as automobiles and trains, but also includes ships, aircraft such as drones, and various robots such as AGVs. The transport equipment is not limited to passenger transport, but may be freight transport, and may be unmanned by remote control or autonomous guidance. A hybrid car is a vehicle equipped with a battery, an engine, and a motor. The light absorbing and heat shielding film 10 and the light absorbing and heat shielding member 100 of the present embodiment can be used as a stray light prevention and heat shielding member inside an optical device, or as an interior and exterior member of space-related equipment such as an artificial satellite, and can also be used as an exterior film, a solar collector, and the like. In addition, the light absorbing and heat shielding film 10 of the present embodiment can be used for clothing, etc. The light absorbing and heat shielding film 10 of the present embodiment may also be used as a heat shielding decorative film. For example, the light absorbing and heat shielding film 10 of the present embodiment can be attached as a heat shielding decorative film to the interior and / or exterior of a vehicle, a mobile device, a home appliance, a parasol, or a tent. When the light absorbing and heat shielding film 10 of the present embodiment is provided on the surface of a member or an article, various adhesives can be used. Therefore, the light-absorbing heat-shielding film 10 of this embodiment can be provided on the surface of components and articles depending on the purpose of use, and the surfaces of the components and articles are not limited to being smooth, but may have two-dimensional or three-dimensional curved surfaces.

[0046] [Second embodiment] The second embodiment relates to a method for manufacturing a light absorbing and heat shielding film and a method for manufacturing a light absorbing and heat shielding member. The method for producing a light absorbing and heat shielding film of the present invention includes the steps of: preparing a mold having a concave-convex shape; forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; After the separating step, a coating layer is formed on the relief structure of the metal layer. In addition, a method for producing a light absorbing and heat shielding member of the present invention includes the steps of: preparing a mold having a concave-convex shape; forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; forming a coating layer on the relief structure of the metal layer after the separating step; a step of adhering a substrate to a surface of the metal layer opposite to a surface onto which the concave-convex shape is transferred; Includes. Hereinafter, a method for manufacturing the light absorbing and heat shielding film 10 and a method for manufacturing the light absorbing and heat shielding member 100 of this embodiment will be described with reference to FIGS. 3A to 3I.

[0047] 3B, the manufacturing method of this embodiment includes a step of preparing a mold 9 having a fine concave-convex shape 92. Since the fine concave-convex shape 92 is included in the concave-convex shape 90, this step can also be said to be a step of preparing a mold 9 having the concave-convex shape 90. The mold 9 has a concave-convex shape 91. The concave-convex shape formed by the concave-convex shape 91 is included in the concave-convex shape 90. The concave-convex shape 91 includes a plurality of recesses (e.g., recesses 911, 912). A plurality of convex portions (e.g., convex portion 910) are provided between the plurality of recesses (e.g., recesses 911, 912) of the concave-convex shape 91.

[0048] The fine uneven shape 92 includes a plurality of recesses (e.g., recesses 921, 922). A plurality of protrusions (e.g., protrusion 920) are provided between the plurality of recesses (e.g., recesses 921, 922) of the fine uneven shape 92. The plurality of recesses (e.g., recesses 921, 922) included in the fine uneven shape 92 are provided on the surface of each of the plurality of recesses (e.g., recesses 911, 912) included in the uneven shape 91.

[0049] The mold 9 may include a substrate 8 and a metal oxide provided on the substrate 8. The metal oxide provided on the substrate 8 may include a metal oxide layer 3 and a metal oxide layer 4 between the metal oxide layer 3 and the substrate 8. Of the metal oxide provided on the substrate 8, the metal oxide layer 3 forms a fine uneven shape 92. That is, each of the multiple convex portions (e.g., convex portion 920) of the fine uneven shape 92 is each of the multiple metal oxide layers 3. The spaces between the multiple metal oxide layers 3 are the multiple concave portions (e.g., concave portions 921, 922) of the fine uneven shape 92. In this way, the mold 9 has a fine uneven shape of a metal oxide. When the fine uneven shape of a metal oxide is focused on a metal oxide, it means the metal oxide layer 3, and when the fine uneven shape is focused on, it means the fine uneven shape 92.

[0050] The manufacturing method of this embodiment includes a step of forming a metal layer 1 to which a fine concave-convex shape 92 is transferred on a mold 9 having the fine concave-convex shape 92, as shown in FIG. 3C. By transferring the fine concave-convex shape 92, the metal layer 1 has a first concave-convex structure 22 reflecting the fine concave-convex shape 92 of the mold 9. At this time, the metal layer 1 also has a second concave-convex structure 21 reflecting the concave-convex shape of the concave-convex shape 91 of the mold 9. In detail, a plurality of recesses (e.g., recesses 911, 912) of the concave-convex shape 91 of the mold 9 are reflected in a plurality of convex portions (e.g., convex portions 211, 212) of the second concave-convex structure 21 shown in FIG. 1. In addition, a plurality of recesses (e.g., recesses 921, 922) of the fine concave-convex shape 92 of the mold 9 are reflected in a plurality of convex portions (e.g., convex portions 221, 222) of the first concave-convex structure 22 shown in FIG. 1.

[0051] The manufacturing method of this embodiment further includes a step of adhering a substrate 5 to the surface of the metal layer 1 of the light absorbing and heat shielding film 10 opposite to the surface to which the fine unevenness 92 is transferred, as shown in FIG. 3D.

[0052] The manufacturing method of this embodiment includes a step of removing at least a part of the mold 9 from above the metal layer 1, as shown in Figs. 3F to 3G. In the step shown in Fig. 3F, the base 8 of the mold 9 is removed. In the step shown in Fig. 3G, the metal oxide layer 4 of the mold 9 is removed. When the base 8 of the mold 9 is made of a light-transmitting material such as glass, the metal layer 1 can be used as a light-absorbing and heat-shielding film without removing the base 8. In other words, it can also be used as a light-absorbing and heat-shielding member 100 having the form shown in Figs. 3D and 3E.

[0053] The steps shown in FIGS. 3A to 3I may be part of a manufacturing method for the light absorbing and heat shielding film 10, or may be part of a manufacturing method for the light absorbing and heat shielding member 100.

[0054] The manufacturing method for the light absorbing and heat shielding film 10 of this embodiment includes a first step of forming a fine unevenness of metal oxide on a base 8, and a second step of forming a metal layer 1 on the fine unevenness of metal oxide. The manufacturing method for the light absorbing and heat shielding member 100 of this embodiment further includes a step of bonding a substrate 5 to the surface of the metal layer 1 of the light absorbing and heat shielding film 10 opposite to the surface in contact with the fine unevenness of metal oxide.

[0055] The first structure (second uneven structure 21) of the hierarchical microstructure in the light-absorbing heat-shielding film 10 reflects the roughness structure size of the base substrate used in the mold 9, and the second structure (first uneven structure 22) reflects the size of the fine uneven shapes 92 of the metal oxide.

[0056] (First step: preparing a mold having a concave-convex shape) The method of manufacturing the light absorbing and heat shielding film 10 and the method of manufacturing the light absorbing and heat shielding member 100 of the present invention include a step of preparing a mold 9 having an uneven shape 90 . In the first step, a metal oxide texture 90 that will become a mold 9 is formed. First, a base substrate is prepared. Hereinafter, the base substrate (substrate) is referred to as a substrate 8 to distinguish it from the substrate 5, but the substrate 8 is synonymous with the base substrate or substrate. The substrate 8 used may be one having a micro-order uneven shape 81 on the surface of the substrate 8, and examples thereof include ground glass roughened with an abrasive or an etching solution such as acid or alkali, and a substrate 8 processed with an electron beam, but are not limited thereto. A micro-order structure may be formed in a film applied to the surface to form the substrate 8.

[0057] As shown in FIG. 3A, the uneven shape 81 of the base 8 has a plurality of recesses (for example, recesses 811, 812) and a plurality of protrusions (for example, protrusion 810 between recesses 811, 812) between the plurality of recesses (for example, recesses 811, 812).

[0058] As shown in FIG. 3A, the aluminum-containing film 7 is formed on a substrate 8 having a micro-order uneven shape 81. The aluminum-containing film 7 is formed along the uneven shape 81 of the substrate 8, and therefore has an uneven shape 71 reflecting the uneven shape 81 of the substrate 8. The uneven shape 71 of the aluminum-containing film 7 has a plurality of recesses (e.g., recesses 711, 712) and a plurality of protrusions (e.g., protrusion 710 between the recesses 711, 712) between the plurality of recesses (e.g., recesses 711, 712). The shapes of the plurality of recesses (e.g., recesses 711, 712) of the aluminum-containing film 7 reflect the shapes of the plurality of recesses (e.g., recesses 811, 812) of the substrate 8, and the shapes of the plurality of protrusions (e.g., protrusion 710) of the aluminum-containing film 7 reflect the shapes of the plurality of protrusions (e.g., protrusion 810) of the substrate 8.

[0059] It is preferable that the mold 9 has a substrate 8 and a metal oxide layer (metal oxide layer 3 and metal oxide layer 4) having an uneven shape 90 on the substrate. As shown in FIG. 3B, a metal oxide layer 3 having a fine uneven shape 92 is formed on the substrate 8. The metal oxide layer 3 having the fine uneven shape 92 is formed by altering the aluminum-containing film 7. Therefore, the metal oxide layer 3 having the fine uneven shape 92 is arranged along a plurality of recesses (e.g., recesses 711, 712) of the aluminum-containing film 7 and a plurality of protrusions (e.g., protrusion 710) of the aluminum-containing film 7. Therefore, the metal oxide layer 3 having the fine uneven shape 92 also constitutes the uneven shape 91 in the uneven shape 90. Note that, as shown in FIG. 3B, a metal oxide layer 4 derived from the aluminum-containing film 7 may be formed between the substrate 8 and the metal oxide layer 3 having the fine uneven shape 92.

[0060] The material of the metal oxide unevenness 90 is not particularly limited, but it is preferable that the material is mainly made of aluminum oxide. The unevenness 90 can be formed by a known gas phase method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), or a liquid phase method using sol-gel. By using these methods, it is possible to provide a fine unevenness of a metal oxide containing plate-like crystals mainly made of aluminum oxide. Among them, the method of growing the aluminum oxide plate-like crystals by immersing the aluminum-containing film 7 in hot water is preferable for the unevenness 90. In this way, it is possible to create the unevenness 90 having Rz and Ra in the above-mentioned preferable ranges.

[0061] Examples of the aluminum-containing film 7 include an aluminum oxide gel film formed by applying a sol-gel coating liquid containing an aluminum compound, and a film containing metallic aluminum formed by dry film formation such as vacuum deposition or sputtering. From the viewpoints of reactivity and ease of adjusting the height of the metal oxide unevenness 90, it is preferable to form the metal oxide unevenness 90 using an aluminum oxide gel film.

[0062] As the raw material for the aluminum oxide gel film, aluminum compounds such as aluminum alkoxides, aluminum halides, aluminum salts, etc. From the viewpoint of film formability, it is preferable to use aluminum alkoxides.

[0063] Examples of aluminum compounds include aluminum alkoxides such as aluminum ethoxide, aluminum isopropoxide, aluminum n-butoxide, aluminum sec-butoxide, and aluminum tert-butoxide, as well as their oligomers, aluminum halides such as aluminum chloride, aluminum salts such as aluminum nitrate, aluminum acetate, aluminum phosphate, and aluminum sulfate, aluminum acetylacetonate, and aluminum hydroxide.

[0064] The aluminum oxide gel film may also contain other compounds. Examples of the other compounds include alkoxides, halides, and salts of zirconium, silicon, titanium, and zinc, and combinations thereof. By including other compounds in the aluminum oxide gel film, the height of the metal oxide projections and recesses 90 formed can be made higher than when the aluminum oxide gel film does not include these compounds.

[0065] The aluminum oxide gel film is formed on the substrate 8 by applying a sol-gel coating liquid containing an aluminum compound as described below. The sol-gel coating liquid is prepared by dissolving the aluminum compound in an organic solvent. The amount of the organic solvent relative to the aluminum compound is preferably about 20 times by molar ratio.

[0066] As the organic solvent, alcohol, carboxylic acid, aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, ester, ketone, ether, or a mixture of these can be used. As the alcohol, for example, methanol, ethanol, 2-propanol, butanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, etc. can be mentioned. Furthermore, 1-propoxy-2-propanol, 4-methyl-2-pentanol, 2-ethylbutanol, 3-methoxy-3-methylbutanol, ethylene glycol, diethylene glycol, glycerin, etc. can be mentioned. As the carboxylic acid, for example, n-butyric acid, α-methylbutyric acid, iso-valeric acid, 2-ethylbutyric acid, 2,2-dimethylbutyric acid, 3,3-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3-methylpentanoic acid, 4-methylpentanoic acid, etc. can be mentioned. Further examples include 2-ethylpentanoic acid, 3-ethylpentanoic acid, 2,2-dimethylpentanoic acid, 3,3-dimethylpentanoic acid, 2,3-dimethylpentanoic acid, 2-ethylhexanoic acid, and 3-ethylhexanoic acid.

[0067] Examples of aliphatic or alicyclic hydrocarbons include n-hexane, n-octane, cyclohexane, cyclopentane, and cyclooctane. Examples of aromatic hydrocarbons include toluene, xylene, and ethylbenzene. Examples of esters include ethyl formate, ethyl acetate, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of ethers include dimethoxyethane, tetrahydrofuran, dioxane, and diisopropyl ether. Among these, it is preferable to use alcohol from the viewpoint of the stability of the sol-gel coating liquid.

[0068] When aluminum alkoxide is used as the aluminum compound, it is highly reactive to water, and therefore the aluminum alkoxide may be rapidly hydrolyzed by the addition of moisture in the air or water, causing the sol-gel coating liquid to become cloudy and precipitate. In order to prevent this, it is preferable to add a stabilizer to the sol-gel coating liquid to stabilize it. As the stabilizer, β-diketone compounds, β-ketoester compounds, alkanolamines, etc. can be used. As the β-diketone compounds, for example, acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, benzoylacetone, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, etc. can be mentioned.

[0069] Examples of β-ketoester compounds include methyl acetoacetate, ethyl acetoacetate, butyl acetoacetate, hexyl acetoacetate, allyl acetoacetate, benzyl acetoacetate, and isopropyl acetoacetate. Examples of further compounds include 2-methoxyethyl acetoacetate, sec-butyl acetoacetate, tert-butyl acetoacetate, and isobutyl acetoacetate. Examples of alkanolamines include monoethanolamine, diethanolamine, and triethanolamine. The amount of the stabilizer relative to the aluminum alkoxide is preferably about 1:1 in molar ratio.

[0070] A catalyst may be used to promote the hydrolysis reaction of the aluminum alkoxide, and examples of the catalyst include nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and ammonia.

[0071] In addition, a water-soluble organic polymer compound can be added to the aluminum oxide gel film as necessary. The water-soluble organic polymer compound is easily dissolved from the aluminum oxide gel film by immersion in hot water, which increases the reaction surface area between the aluminum compound and hot water, making it possible to form the uneven shape 90 at a low temperature and in a short time. In addition, by changing the type and molecular weight of the organic polymer to be added, it becomes possible to control the height of the uneven shape 90 to be formed. As the organic polymer, polyether glycols such as polyethylene glycol and polypropylene glycol are preferable because they are easily dissolved from the aluminum oxide gel film by immersion in hot water. The amount of polyether glycols relative to the mass of the aluminum compound in the aluminum oxide gel film is preferably in the range of 0.1 to 10 times by mass ratio.

[0072] The method of forming the metal oxide features 90 will now be described in detail with reference to Figures 3A and 3B. 3A, an aluminum compound, and if necessary, other compounds, a stabilizer, and a water-soluble organic polymer compound are dissolved or suspended in an organic solvent to prepare a sol-gel coating liquid. This sol-gel coating liquid is applied to a substrate 8 and dried to form an aluminum oxide gel film as the aluminum-containing film 7. Alternatively, a film containing metallic aluminum as the aluminum-containing film 7 is formed on the substrate 8 by dry film formation such as vacuum deposition or sputtering.

[0073] The material of the substrate 8 is not particularly limited, and various materials such as glass, plastic, and metal can be used. When forming an aluminum oxide gel film using a sol-gel coating solution that does not contain a stabilizer, it is preferable that the atmosphere in which the coating is performed is an inert gas atmosphere such as dry air or dry nitrogen. The relative humidity of the dry atmosphere is preferably 30% or less. As a solution coating method for forming an aluminum oxide gel film, known coating means such as a dipping method, a spin coating method, a spray method, a printing method, a flow coating method, and a combination of these methods can be appropriately adopted.

[0074] The film thickness can be controlled by changing the pulling speed in the dipping method, the substrate rotation speed in the spin coating method, and the concentration of the sol-gel coating liquid. Drying can be performed at room temperature for about 30 minutes. If necessary, drying or heat treatment can be performed at a higher temperature. The higher the heat treatment temperature, the more stable the fine unevenness 92 of the metal oxide layer 3 can be formed by the immersion treatment described later. The suitable film thickness of the aluminum-containing film 7 is 100 nm or more and 600 nm or less, preferably 100 nm or more and 300 nm or less, and more preferably 100 nm or more and 200 nm or less.

[0075] Next, in the step shown in FIG. 3B, the aluminum oxide-containing uneven shape 90 is preferably formed by immersing the aluminum-containing film 7 in hot water. By immersing the aluminum oxide gel film in hot water, the surface layer of the aluminum oxide gel film is subjected to peptization and the like. Although some components are eluted, due to differences in the solubility of various hydroxides in hot water, plate-like crystals mainly composed of aluminum oxide are precipitated, grown, and formed on the surface layer of the aluminum oxide gel film. In addition, a metal oxide layer 4 containing amorphous gel of aluminum oxide, which is the above-mentioned metal oxide layer 4 (see FIG. 1), is formed on the base 8.

[0076] As a result, the fine unevenness 92 of the metal oxide layer 4 and the metal oxide layer 3 is formed as described above (see FIG. 1). Furthermore, when a film containing metallic aluminum is used instead of the aluminum oxide gel film, the aluminum reacts with the hot water and is oxidized to aluminum oxide. Thereafter, the fine unevenness 92 of the metal oxide layer 3 is formed on the surface of the film containing metallic aluminum, similar to the case where an aluminum oxide gel film is used. Therefore, when the material of the base 8 mainly contains aluminum or aluminum oxide, the formation of the film 7 containing aluminum on the base 8 can be omitted.

[0077] The temperature of the hot water is preferably 40°C or higher and lower than 100°C. The immersion time is preferably about 5 minutes to 24 hours. In the immersion treatment of an aluminum oxide gel film containing compounds other than the aluminum oxide component, the difference in solubility of each component in hot water is used to crystallize the aluminum oxide plate crystals. Therefore, unlike the immersion treatment of an aluminum oxide gel film containing only aluminum oxide, the size of the plate crystals can be controlled over a wide range by changing the composition of the inorganic component. The height of the fine unevenness 92 of the metal oxide layer 4 and the metal oxide layer 3 can also be adjusted by adjusting the film thickness of the aluminum-containing film 7.

[0078] The average height of the fine unevenness 92 of the metal oxide layer 3 is preferably 100 nm or more and 1000 nm or less, and more preferably 100 nm or more and 500 nm or less. As a result, it becomes possible to control the fine unevenness formed by the plate crystals over the above-mentioned wide range.

[0079] (Second step: forming a metal layer) The method of manufacturing the light absorbing and heat shielding film 10 and the method of manufacturing the light absorbing and heat shielding member 100 of the present invention include a step of forming, on a mold 9, a metal layer 1 having a concave-convex structure 2 to which a concave-convex shape 90 has been transferred. In the second step, the metal layer 1 is formed on the metal oxide concave-convex shape 90, thereby forming the metal layer 1 having the fine concave-convex structure portion 2 to which the fine concave-convex shape 92 of the mold 9 is transferred. With reference to FIG. 3C, the step of forming the metal layer 1 on the metal oxide fine concave-convex shape 92 will be described below. As a method for forming the metal layer 1, a metal plating process is preferable, and an electroless plating process is more preferable. In the electroless plating process, an aqueous solution in which a palladium compound such as palladium chloride, a gold compound such as gold chloride, a silver compound such as silver chloride, a tin compound such as tin chloride, or the like is dissolved is applied to the metal oxide fine concave-convex shape 92 to perform activation. The activation may be performed by immersing the metal oxide fine concave-convex shape 92 together with the substrate 8 in an aqueous solution in which a palladium compound is dissolved.

[0080] Thereafter, the metal layer 1 is deposited on the fine unevenness 92 of the metal oxide using an electroless plating solution. The metal ions in the electroless plating solution correspond to the metal layer 1 of the light absorbing and heat shielding film 10 of this embodiment, and an electroless plating solution containing nickel ions, chromium ions, and zinc ions is preferable, and a nickel plating solution containing nickel ions is particularly preferable. The nickel plating solution may contain a phosphorus component or a boron component in addition to the nickel component. Examples of commercially available nickel plating solutions include the Top Nicoron (registered trademark) series by Okuno Chemical Industries. The temperature of the plating solution in the electroless plating process is preferably 30° C. or higher and 98° C. or lower, more preferably 50° C. or higher and 90° C. or lower. The time for which the electroless plating process is performed can be adjusted depending on the thickness of the metal layer 1 to be formed, and is usually 30 seconds to 1 hour.

[0081] It is preferable that at least a part of the metal oxide layers 3 and 4 adhere to the metal layer 1 separated from the mold 9. Here, at least a part of the metal oxide layers 3 and 4 is the metal oxide layer 3 or the metal oxide layers 3 and 4. In this way, the fine concave-convex structure 2 can be protected. In this way, the metal layer 1 is formed so as to fill the gaps of the fine concave-convex shape 92, and the metal layer 1 including the fine concave-convex structure 2 to which the fine concave-convex shape 92 of the metal oxide is transferred is formed. At this time, the part located above (on the opposite side to the mold 9) the apex of the convex part (for example, the convex part 910) of the concave-convex shape 91 becomes the base 11, and the part located below (on the mold 9 side) the apex of the convex part (for example, the convex part 910) of the concave-convex shape 91 becomes the fine concave-convex structure 2. In other words, the metal layer 1 including the base 11, the first concave-convex structure 22 (second structure), and the second concave-convex structure 21 (first structure) is formed. The metal layer 1 including the base 11, the first concave-convex structure 22 (second structure), and the second concave-convex structure 21 (first structure) is preferably a plated layer.

[0082] Moreover, it is preferable that the main component of the metal material of the metal layer 1 including the base 11, the first uneven structure 22, and the second uneven structure 21 is the same. It is preferable to perform electroless plating so that the thickness of the metal layer 1 including the fine concave-convex structure 2 is 200 nm or more and 15,000 nm or less. The metal layer 1 is formed so as to cover the apex of the convex portion (e.g., the convex portion 910) of the concave-convex shape 91, and this portion becomes the base portion 11, so the thickness of the base portion 11 can be 200 nm or more and 15,000 nm or less. In addition, the average height of the first concave-convex structure 22 in the fine concave-convex structure 2 corresponds to the average height of the fine concave-convex shape 92 of the metal oxide, and is 100 nm or more and 1000 nm or less. When the thickness of the metal layer 1 including the fine concave-convex structure 2 is 200 nm or more, the light absorbing and heat shielding film 10 of this embodiment exhibits excellent light absorbing and heat shielding properties.

[0083] After the electroless plating process described above, an electroplating process may be performed on the surface of the metal layer 1 opposite to the surface on which the fine concave-convex structure 2 is provided, in order to increase the thickness of the metal layer 1. A known electroplating solution may be used for the electroplating process, and for example, an electroplating solution containing nickel ions, iron ions, copper ions, etc. as metal ions may be used. When the electroplating process is performed using the same metal as that of the metal layer 1, the thickness of the metal layer 1 can be increased by the electroplating process.

[0084] When electroplating is performed on the metal layer 1 using a metal different from the metal of the metal layer 1, the metal layer 1 formed by electroplating becomes the substrate 5. In addition to the inorganic salt that is the source of the metal ions, the electroplating solution may contain conductive salts, salts for adjusting counter ions, carboxylic acid additives for improving the homogeneity of the plating film, gloss agents, etc., as necessary.

[0085] In the electroplating step, the thickness of the metal layer 1 can be adjusted to a desired thickness by adjusting the temperature of the electroplating solution, the current density, and the plating time. If necessary, the surface of the metal layer 1 opposite to the surface on which the fine relief structure 2 is provided may be activated with an aqueous solution containing an acid or the like prior to the electroplating step. Furthermore, in order to improve the quality of the film formed by the electroplating step, a step of removing foreign matter from the electroplating solution may be included in addition to stirring the electroplating solution during the electroplating process.

[0086] (Third step: bonding the substrate) The method for manufacturing the light absorbing and heat shielding member 100 of the present invention includes a step of adhering a substrate 5 to the surface of the metal layer 1 opposite to the surface to which the unevenness pattern 90 is transferred. The step of adhering the substrate 5 is preferably performed after the step of forming the metal layer 1 and before the step of separating the metal layer 1 from the mold 9. In the manufacture of the light absorbing and heat shielding member 100 of this embodiment, as shown in FIG. 3D, the substrate 5 is bonded to the surface of the metal layer 1 obtained above on the opposite side to the surface on which the fine uneven structure 2 is provided. The shape and material of the substrate 5 may be the same as those described above. When the substrate 5 is made of a metal, a metal that will become the substrate 5 may be further laminated on the surface of the metal layer 1 opposite to the surface on which the fine uneven structure 2 is provided. The metal may be laminated by the above-mentioned electroplating process or by physical vapor deposition such as sputtering. When the substrate 5 is made of a resin, the substrate 5 may be provided by depositing a resin that will become the substrate 5 on the surface of the metal layer 1 opposite to the fine uneven structure 92 of the metal oxide and then curing the resin. The substrate 5 may be bonded to the metal layer 1 by an adhesive layer 6. The adhesive used for the adhesive layer 6 is not particularly limited, and may be a material that can firmly bond the substrate 5 and the metal layer 1.

[0087] (4th step: Separating the metal layer from the mold) The method for manufacturing the light absorbing and heat shielding film 10 and the method for manufacturing the light absorbing and heat shielding member 100 of the present invention include a step of separating the metal layer 1 from the mold 9. It is preferable to remove at least a part of the metal oxide layers 3 and 4 attached to the metal layer 1 from above the metal layer 1 before the step of forming the coating layer 40 (fifth step). 3E to 3G, the process of separating the metal layer 1 from the mold 9 will be described in detail using as an example a light absorbing and heat shielding member 100 including a base material 5 and an adhesive layer 6, but the same applies to a light absorbing and heat shielding member 100 including only the base material 5 without the adhesive layer 6, and a light absorbing and heat shielding film including neither the base material 5 nor the adhesive layer 6. Note that Fig. 3E shows the light absorbing and heat shielding member 100 shown in Fig. 3D turned upside down.

[0088] First, in order to obtain the light absorbing and heat shielding member 100 of this embodiment, the base 8 is removed as shown in Fig. 3F. After removing the base 8, the light absorbing and heat shielding member 100 has a film 7 containing metallic aluminum or a metal oxide layer 4 on its surface. In the case of a film containing metallic aluminum, visible light is reflected by metallic aluminum, so that the film containing metallic aluminum must be further removed by etching as shown in Fig. 3G.

[0089] In the case of a metal oxide layer 4, the metal oxide layer 4 of the light absorbing and heat shielding member 100 is a layer containing an amorphous gel of aluminum oxide. Therefore, the layer containing the amorphous gel of aluminum oxide may be removed by etching so as to satisfy the required surface hardness and light absorption. As an etching method, wet etching is preferred in which an acid or alkaline solution is used to dissolve the film containing metallic aluminum or the metal oxide layer 4.

[0090] Examples of acids include hydrochloric acid, nitric acid, and sulfuric acid. Examples of alkalis include sodium hydroxide and potassium hydroxide. From the viewpoint of work efficiency, an etching method using an alkaline solution is more preferable. The etching concentration is preferably in the range of several percent to several tens of percent, and the etching time is preferably in the range of several hours to several days. The metal layer 1 having a metal oxide attached to the fine concave-convex structure 2 also has excellent light absorption properties, and the strength of the fine concave-convex structure 2 can be improved, so that it is also excellent in durability and environmental resistance.

[0091] Residual metal oxide such as aluminum oxide after etching (metal oxide adhering to the fine concave-convex structure 2) can be detected by EDX or XPS measurement during surface or cross-sectional observation by SEM or TEM.

[0092] As described above, the degree of etching may be adjusted depending on the balance between the light absorbing performance and surface hardness of the desired light absorbing and heat shielding member 100 or light absorbing and heat shielding film 10. Furthermore, the etching step of this step may be performed before the bonding step of the substrate 5, which is the third step, and then the substrate 5 may be bonded.

[0093] (5th step: forming a coating layer) The manufacturing method of the light absorbing and heat shielding film 10 and the manufacturing method of the light absorbing and heat shielding member 100 of the present invention include a step of forming a coating layer 40 on the uneven structure 2 of the metal layer 1 after a step of separating the metal layer 1 from the mold 9. The coating layer 40 preferably covers at least the part of the metal oxide layers 3, 4 attached to the metal layer 1. In this way, it is possible to impart abrasion resistance to the light absorbing and heat shielding film 10. In the step of forming the coating layer 40, as shown in Figures 3H to 3I, a coating layer 40 for improving mechanical strength is formed on the outermost surface of the light absorbing and heat shielding member 100. In the step of forming the coating layer 40, the coating layer 40 is formed of siloxane, particularly the above-mentioned silsesquioxane, for example. The explanation of silsesquioxane as a material is as above, and therefore will not be repeated.

[0094] The silsesquioxane preferably has a polymerizable group (R1 in the above formula) in the molecule and is a compound that cures by radical polymerization or cationic polymerization. Examples of silsesquioxane that cures by radical polymerization include an acryloyl group or a methacryloyl group as R. On the other hand, examples of silsesquioxane that cures by cationic polymerization include an oxetanyl group or an epoxy group as R. Specific examples include the silsesquioxane derivative SQ series (AC-SQ, MAC-SQ, OX-SQ) manufactured by Toa Gosei Co., Ltd. Since silsesquioxane is a highly viscous liquid, it is preferable to add it to the above-mentioned coating liquid before use. The content of silsesquioxane in the coating liquid is preferably 1 part by mass to 10 parts by mass, more preferably 2 parts by mass to 8 parts by mass.

[0095] If necessary, a polymerization initiator can be added. Examples of the polymerization initiator include a photoradical polymerization initiator, a photocationic polymerization initiator, a thermal radical polymerization initiator, and a thermal cationic polymerization initiator. These polymerization initiators may be composed of one type of polymerization initiator or may be composed of multiple types of polymerization initiators. Examples of the photoradical polymerization initiator include the following.

[0096] For example, 2,4,5-triarylimidazole dimers which may have a substituent such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o- or p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), ... Benzophenone derivatives such as 4-ethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and 4,4'-diaminobenzophenone; α-amino aromatic ketone derivatives such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one; 2-ethylanthraquinone, phenanthrenequinone, 2-t quinones such as butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone; benzoin ether derivatives such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; Benzoin derivatives such as zoin, methylbenzoin, ethylbenzoin, and propylbenzoin; benzil derivatives such as benzil dimethyl ketal; acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; N-phenylglycine derivatives such as N-phenylglycine; acetophenone derivatives such as acetophenone, 3-methylacetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone;Thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone and other thioxanthone derivatives; acylphosphine oxide derivatives such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O- oxime ester derivatives such as 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the like, but are not limited thereto. Commercially available photoradical polymerization initiators include Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1173, Lucirin TPO, LR8893, LR8970 (all manufactured by BASF, "Darocur" and "Lucirin" are registered trademarks), Ubecryl P36 (manufactured by UCB), San-Apro CPI-210S (manufactured by San-Apro), and the like, but are not limited thereto;

[0097] As the photocationic polymerization initiator, onium salt, aromatic onium salt, arylsulfonium salt, and aryliodonium salt are preferable. Specific examples of the anion include tetrafluoroborate ion, hexafluorophosphate ion, hexafluoroantimonate ion, perchlorate ion, trifluoromethanesulfonate ion, and fluorosulfonate ion. Commercially available photocationic polymerization initiators include San-Apro CPI-210S (San-Apro), UVI-6950 (Union Carbide), and Adeka Optomer SP-150 (ADEKA). The content of the polymerization initiator in the coating liquid is preferably 0.01% by mass to 1.5% by mass, more preferably 0.03% by mass to 1.0% by mass, based on the silsesquioxane solid content concentration.

[0098] The above-mentioned silsesquioxane and polymerization initiator may be dissolved in a solvent to prepare a coating liquid. The solvent is preferably an organic solvent. The organic solvent is not particularly limited, but alcohol, carboxylic acid, aliphatic or alicyclic hydrocarbons, aromatic hydrocarbons, esters, ketones, ethers, or a mixture of two or more of these may be used. The alcohol is preferably, for example, methanol, ethanol, 2-propanol, butanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, 4-methyl-2-pentanol, 2-ethylbutanol, 3-methoxy-3-methylbutanol, ethylene glycol, diethylene glycol, glycerin, or the like. As the carboxylic acid, specifically, n-butyric acid, α-methylbutyric acid, i-valeric acid, 2-ethylbutyric acid, 2,2-dimethylbutyric acid, 3,3-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3-methylpentanoic acid, 4-methylpentanoic acid, 2-ethylpentanoic acid, 3-ethylpentanoic acid, 2,2-dimethylpentanoic acid, 3,3-dimethylpentanoic acid, 2,3-dimethylpentanoic acid, 2-ethylhexanoic acid, and 3-ethylhexanoic acid are preferably used. As the aliphatic or alicyclic hydrocarbons, specifically, n-hexane, n-octane, cyclohexane, cyclopentane, and cyclooctane are preferable. As the aromatic hydrocarbons, toluene, xylene, and ethylbenzene are preferable. As the esters, ethyl formate, ethyl acetate, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, and γ-butyrolactone are preferable. Preferred ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Preferred ethers include dimethoxyethane, tetrahydrofuran, dioxane, diisopropyl ether, etc.

[0099] It is preferable that the coating layer 40 is formed by applying a liquid. When preparing the coating liquid, it is preferable to use alcohols among the above-mentioned various solvents in terms of the stability of the solution. The liquid to be applied (coating liquid) preferably contains silsesquioxane. The coating liquid can be prepared by adding a predetermined amount of silsesquioxane to an organic solvent, and further adding a polymerization initiator as necessary.

[0100] In addition, when a fluororesin is used for the organic material coating layer 40, it is preferable that the fluoroolefin copolymer contains a fluoroolefin copolymer. The fluoroolefin copolymer preferably has a functional group capable of reacting with a curing agent described below to form a cross-linked bond. The type of functional group can be appropriately selected depending on the combination with the curing agent. Representative examples include a hydroxyl group, a carboxyl group, an epoxy group, and an amino group.

[0101] Specific examples of fluoroolefin copolymers include copolymers of chlorotrifluoroethylene, cyclohexyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether, copolymers of chlorotrifluoroethylene, alkyl vinyl ether, and allyl alcohol, copolymers of chlorotrifluoroethylene, aliphatic carboxylic acid vinyl ester, and hydroxyalkyl vinyl ether, etc. These are also commercially available under the trade name Lumiflon (registered trademark) (manufactured by AGC Corporation). The fluoroolefin copolymer may be used alone or in combination of two or more kinds.

[0102] As the curing agent, various curing agents can be used. Specific examples of the curing agent include amino-based curing agents such as urea resins, polyvalent isocyanate-based curing agents, etc. The curing agent may be used alone or in combination of two or more. The solvent is not particularly limited as long as it is generally used for paints, and examples thereof include esters such as toluene, xylene, ethyl acetate, and butyl acetate, and ketones such as methyl ethyl ketone and methyl isobutyl ketone. These may be used alone or in combination of two or more kinds.

[0103] When forming a layer using a coating liquid, it is preferable to carry out the coating in an inert gas atmosphere such as dry air or dry nitrogen. The relative humidity of the dry atmosphere is preferably 30% or less. In this way, it is possible to impart abrasion resistance to the light absorbing and heat shielding film 10.

[0104] Furthermore, known coating means such as dipping, spin coating, spraying, printing, flow coating, and combinations of these can be appropriately used as the solution coating method for forming the coating layer 40. The film thickness can be controlled by changing the pulling speed in the dipping method or the substrate rotation speed in the spin coating method, and by changing the concentration of the coating solution. The resulting coating layer 40 may be cured by irradiation with high energy rays such as light or radiation, or by heating. Curing may also be performed by a combination of high energy ray irradiation and heating.

[0105] In the case of curing by irradiation with high-energy rays, examples of the high-energy rays include, but are not limited to, electron beams, X-rays, ultraviolet rays, etc. When ultraviolet rays are used as the high-energy rays, the irradiation wavelength range is preferably 160 nm to 400 nm, and the output is 0.1 to 2000 mW / cm 2 From the viewpoint of preventing oxidation of silsesquioxane, it is preferable to use an inert atmosphere such as nitrogen as the curing atmosphere. In the case of thermal curing, it is preferable to carry out at a temperature of 50°C to 250°C, more preferably at a temperature of 80°C to 200°C, for 1 to 20 minutes. The suitable thickness of the silsesquioxane layer is from 20 nm to 180 nm, preferably from 30 nm to 150 nm.

[0106] In the step of forming the coating layer 40 of the present invention, it is preferable to further include a step of forming a coating layer 40 of an organic material after the step of forming the coating layer 40 of the inorganic material (e.g., a layer of silsesquioxane) described above. Materials used for the coating layer 40 of an organic material include fluororesin and acrylic resin. The coating layer 40 of an organic material is preferably formed on the coating layer 40 of the inorganic material (layer of silsesquioxane) described above. In this way, weather resistance can be imparted to the light absorbing and heat shielding film 10. The explanation of organic materials such as fluororesin and acrylic resin is omitted since it is the same as above.

[0107] The light-absorbing and heat-shielding member and light-absorbing and heat-shielding film of this embodiment obtained in this manner have mechanical strength on the film surface, and therefore it is possible to provide an excellent light-absorbing and heat-shielding film and light-absorbing and heat-shielding member that combines light-absorbing and heat-shielding properties with abrasion resistance. EXAMPLES

[0108] The present invention will now be described more specifically with reference to examples. However, the present invention is not limited to the following examples. The visible light absorbance of the examples was evaluated by measuring the reflectance spectrum in the visible light region using a lens reflectance measuring instrument (product name: USPM-RU III, manufactured by Olympus Corporation). The heat shielding properties of the examples were evaluated by measuring the reflectance spectrum in the infrared region using a Fourier transform infrared spectrophotometer (FT / IR-6600, manufactured by JASCO Corporation). The wear resistance test of the examples was carried out as follows. A load of 100 g was applied to a slider with Silbon paper attached using a surface tester, HEIDON Type: 38 (manufactured by Shinto Scientific Co., Ltd.), and the sample was worn for 1 minute at a speed of 50 reciprocations per minute. Wear resistance was evaluated by optical microscope observation and reflectance measurement. For optical microscope observation, an optical microscope (Olympus, BX51M) was used.

[0109] Example 1 (Manufacture of light absorbing and heat shielding materials) Aluminum sec-butoxide (hereinafter, also referred to as "Al(O-sec-Bu)3") and ethyl acetoacetate (hereinafter, also referred to as "EtOAcAc") were dissolved in 2-propanol (hereinafter, also referred to as "IPA") and stirred at room temperature for about 3 hours to prepare an aluminum oxide sol solution. The molar ratio of each component in the aluminum oxide sol solution was Al(O-sec-Bu)3: EtOAcAc: IPA = 1: 1: 20. A 0.01M dilute hydrochloric acid solution was added to the aluminum oxide sol solution so that the amount of hydrochloric acid added was twice that of Al(O-sec-Bu)3 in terms of molar ratio, and the solution was refluxed for about 6 hours to prepare a sol-gel coating solution. The sol-gel coating solution was applied by spin coating to a quartz glass substrate #240 (#240 is the number of the grinding polishing) with a ground surface as a base substrate to form a coating film. The coating film was then heat-treated at 100°C for 1 hour to obtain a transparent aluminum oxide gel film. Next, the aluminum oxide gel film was immersed in warm water at 80° C. for 30 minutes, and then dried at 100° C. for 10 minutes to form an aluminum oxide layer having a fine concave-convex shape.

[0110] An aqueous palladium chloride solution was applied by spin coating onto the aluminum oxide layer having the fine concave-convex structure, and then dried at 100°C. The substrate was then immersed in a nickel-phosphorus plating solution (phosphorus content: approximately 1-2 wt%) set at 80°C for 20 minutes to form a nickel layer as a metal layer having a fine concave-convex structure and a base portion thereunder. The light-absorbing and heat-shielding film was then peeled off from the quartz glass substrate, and etched at room temperature for 50 hours using a 3M aqueous sodium hydroxide solution as an etching process, to produce a light-absorbing and heat-shielding film. The overall film thickness of the obtained light-absorbing and heat-shielding film was approximately 10 μm.

[0111] (Surface treatment process A) Silsesquioxane (manufactured by Toagosei Co., Ltd., OX-SQ SI-20) was dissolved in propylene glycol monomethyl ether (PGME) and a thermal cationic polymerization initiator (San-Aid SI-100L, diluted with γ-butyrolactone) was added to the solution to adjust the silsesquioxane concentration to 5% by mass. The solution was applied to the light-absorbing and heat-shielding film by spin coating to form a coating layer. The coating film was then heat-treated at 200°C for 1 hour to obtain a surface-treated light-absorbing and heat-shielding film.

[0112] Example 2 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the silsesquioxane concentration was changed to 3 mass %.

[0113] Example 3 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the silsesquioxane concentration was changed to 2 mass %.

[0114] Example 4 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the base material was changed to #1200 ground glass.

[0115] Example 5 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the base material was changed to #600 ground glass.

[0116] Example 6 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the base material was changed to #400 ground glass.

[0117] Example 7 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the base material was changed to #120 ground glass.

[0118] Example 8 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the base material was changed to mirror-polished glass.

[0119] (Surface treatment process B) A base material was prepared by dissolving fluororesin Lumiflon (LF-200, manufactured by AGC Corporation), which is a fluoroolefin polymer, in a solvent of xylene, and a curing agent was prepared by dissolving non-yellowing type polyisocyanate (Coronate HX, manufactured by Tosoh Corporation) in a solvent of xylene. Then, a predetermined amount of the base material, the curing agent, and dibutyltin dilaurate as a catalyst were mixed to prepare a coating liquid of 25% by mass. The liquid was applied onto the light-absorbing and heat-shielding film by spin coating to form a coating layer. Then, the coating film was heat-treated at 200°C for 1 hour to obtain a surface-treated light-absorbing and heat-shielding film.

[0120] Example 9 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that the surface treatment step was changed from A to B.

[0121] Example 10 A light-absorbing and heat-shielding film was produced in the same manner as in Example 9, except that the base material was changed to #1200 ground glass.

[0122] Example 11 A light-absorbing and heat-shielding film was produced in the same manner as in Example 9, except that the base material was changed to #600 ground glass.

[0123] Example 12 A light-absorbing and heat-shielding film was produced in the same manner as in Example 9, except that the base material was changed to #400 ground glass.

[0124] Example 13 A light-absorbing and heat-shielding film was produced in the same manner as in Example 9, except that the base material was changed to #120 ground glass.

[0125] Example 14 A light-absorbing and heat-shielding film was produced in the same manner as in Example 9, except that the base material was changed to mirror-polished glass.

[0126] Comparative Example 1 A light-absorbing and heat-shielding film was produced in the same manner as in Example 1, except that #240 ground glass was used as the base material and no surface treatment step using silsesquioxane or fluororesin was performed.

[0127] Comparative Example 2 A light-absorbing and heat-shielding film was produced in the same manner as in Example 8, except that mirror-polished glass was used as the base material and no surface treatment step using silsesquioxane or fluororesin was performed.

[0128] (evaluation) The evaluation results of the visible light absorbency, heat shielding property, and abrasion resistance of the light absorbing and heat shielding films produced in the examples and comparative examples are shown in Table 1. Films with low reflectance in the visible light region and excellent light absorbency were rated A for visible light absorbency, and films with high reflectance toward the long wavelength side in the mid-infrared and far-infrared regions and excellent heat shielding property were rated A for heat shielding property.

[0129] Regarding abrasion resistance, if no noticeable wear marks were observed by optical microscope observation after the abrasion test and there was no significant change in reflectance in the visible light and infrared light regions before and after the abrasion test, the abrasion resistance was rated as A, and if noticeable wear marks were observed by optical microscope observation after the abrasion test or there was a significant change in reflectance in the visible light and infrared light regions before and after the abrasion test, the abrasion resistance was rated as B. The results are shown in Table 1 below.

[0130] [Table 1]

[0131] 4 and 5 show optical microscope photographs of the light-absorbing and heat-shielding film obtained in Example 1 before and after the abrasion test. FIG. 4 is a photograph before the abrasion test, and FIG. 5 is a photograph after the abrasion test. It can be seen that no noticeable abrasion marks were observed even after the abrasion test, and no deterioration of the surface was observed. In addition, no significant change in the reflectance of visible light and infrared rays was observed before and after the abrasion test. In contrast, when the abrasion test was performed in Comparative Example 1, noticeable abrasion marks that appeared white were observed after the abrasion test, as shown in FIG. 6. When the abrasion test was performed in Comparative Example 2, noticeable abrasion marks were observed, and a significant change in the reflectance of visible light and infrared rays was observed before and after the abrasion test.

[0132] The present invention includes the following embodiments. (Configuration 1) A metal layer having a main surface including a first uneven structure; a metal oxide layer provided on the main surface; a coating layer formed on the metal oxide layer and made of a material different from that of the metal oxide layer; Including, The light-absorbing and heat-shielding film, wherein the first uneven structure has an arithmetic mean roughness Ra of 1 nm or more and 50 nm or less, and a maximum height Rz of the first uneven structure of 100 nm or more and 800 nm or less. (Configuration 2) 2. The light absorbing and heat shielding film according to claim 1, wherein the coating layer contains Si and O. (Configuration 3) 3. The light-absorbing and heat-shielding film according to configuration 1 or 2, wherein the coating layer contains siloxane. (Configuration 4) 4. The light-absorbing and heat-shielding film according to any one of configurations 1 to 3, wherein the coating layer contains silsesquioxane. (Configuration 5) The coating layer contains silsesquioxane, and the silsesquioxane is [R(SiO 1.5 ) n 5. The light-absorbing and heat-shielding film according to any one of configurations 1 to 4, wherein R1 is a polymerizable group when the compound is represented by the formula: (Configuration 6) The coating layer contains silsesquioxane, and the silsesquioxane is [R(SiO 1.5 ) nwherein R1 is at least one polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an oxetanyl group, and an epoxy group. (Configuration 7) 7. The light-absorbing and heat-shielding film according to any one of configurations 1 to 6, wherein the coating layer contains a fluororesin or an acrylic resin. (Configuration 8) 8. The light-absorbing and heat-shielding film according to any one of configurations 1 to 7, wherein the coating layer contains a fluoroolefin-based polymer. (Configuration 9) 9. The light-absorbing and heat-shielding film according to any one of configurations 1 to 8, wherein the metal component of the metal oxide layer is different from the metal component of the metal layer. (Configuration 10) 10. The light-absorbing and heat-shielding film according to any one of configurations 1 to 9, wherein the metal oxide layer contains aluminum oxide. (Configuration 11) 11. The light-absorbing and heat-shielding film according to any one of configurations 1 to 10, wherein the metal layer contains any one selected from the group consisting of nickel, chromium, and zinc. (Configuration 12) The light-absorbing and heat-shielding film according to any one of configurations 1 to 11, wherein the metal layer includes a second uneven structure, the arithmetic mean roughness Ra of the second uneven structure is 0.1 μm or more and 5 μm or less, and the maximum height Rz of the second uneven structure is 1 μm or more and 10 μm or less. (Configuration 13) 13. The light absorbing and heat shielding film according to configuration 12, wherein the first uneven structure is formed on an upper surface of the second uneven structure. (Configuration 14) 14. The light absorbing and heat shielding film according to any one of configurations 1 to 13, wherein the metal oxide layer is formed in a film shape, filling the recesses of the first uneven structure. (Configuration 15) 15. A light absorbing and heat shielding member comprising the light absorbing and heat shielding film according to any one of configurations 1 to 14, and a substrate provided on the surface opposite to the surface having the first uneven structure. (Configuration 16) An article comprising the light-absorbing and heat-shielding film according to any one of configurations 1 to 14. (Configuration 17) A step of preparing a mold having a concave and convex shape; forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; forming a coating layer on the relief structure of the metal layer after the separating step; A method for producing a light absorbing and heat shielding film comprising the steps of: (Configuration 18) 18. The method for producing a light-absorbing and heat-shielding film according to configuration 17, wherein the mold has a base and a metal oxide layer having the uneven shape on the base. (Configuration 19) 19. The method of claim 18, wherein at least a portion of the metal oxide layer adheres to the metal layer that has been separated from the mold. (Configuration 20) 20. The method for producing a light absorbing and heat shielding film according to claim 19, wherein the coating layer covers at least the portion of the metal oxide layer attached to the metal layer. (Configuration 21) 21. The method for producing a light absorbing and heat shielding film according to any one of configurations 17 to 20, wherein the coating layer is formed by coating a liquid. (Configuration 22) 22. The method for producing a light absorbing and heat shielding film according to claim 21, wherein the liquid contains silsesquioxane. (Configuration 23) 23. The method for producing a light absorbing and heat shielding film according to any one of configurations 17 to 22, wherein the uneven shape is formed by immersing an aluminum-containing film in warm water. (Configuration 24) The method for producing a light absorbing and heat shielding film according to any one of configurations 17 to 23, wherein at least a portion of the metal oxide layer attached to the metal layer is removed from above the metal layer before the step of forming the coating layer. (Configuration 25) A step of preparing a mold having a concave and convex shape; forming a metal layer having a concave-convex structure to which the concave-convex shape is transferred on the mold; separating the metal layer from the mold; forming a coating layer on the relief structure of the metal layer after the separating step; a step of adhering a substrate to a surface of the metal layer opposite to a surface onto which the concave-convex shape is transferred; A method for producing a light absorbing and heat shielding member comprising the steps of: (Configuration 26) 26. The method for producing a light absorbing and heat shielding member according to configuration 25, wherein the step of adhering the base material is performed after the step of forming the metal layer and before the step of separating. [Industrial Applicability]

[0133] The present invention provides an excellent light-absorbing and heat-shielding film and a light-absorbing and heat-shielding member that have both light-absorbing and heat-shielding properties and abrasion resistance. By using an optical element made of a metal material having a microstructure and a coating protective layer on its surface, it is possible to achieve both light-absorbing and heat-shielding properties and abrasion resistance. [Explanation of symbols]

[0134] 1...metal layer 2...Minute uneven structure (uneven structure) 3. Metal oxide layer 4. Metal oxide layer 5...Base material 7. Aluminum-containing film 8...Base 9··· type 10...Light absorption heat shield film 21...Second uneven structure 22...First uneven structure 40...Covering layer 90...Uneven shape 100... Light absorbing and heat shielding member 220...recess

Claims

1. A metal layer having a first structure in which the main surface includes multiple protrusions, A metal oxide layer provided on the main surface, A coating layer provided on the metal oxide layer, wherein the material of the coating layer is different from that of the metal oxide layer. Includes, A light-absorbing heat-shielding film wherein the arithmetic mean roughness Ra of the main surface on which the first structure is provided is 1 nm or more and 50 nm or less, and the maximum height Rz of the main surface on which the first structure is provided is 100 nm or more and 800 nm or less.

2. The light-absorbing heat-shielding film according to claim 1, wherein the thickness of the coating layer is 20 nm or more and 180 nm or less.

3. The light-absorbing heat-shielding film according to claim 1, wherein the coating layer comprises Si and O.

4. The light-absorbing, heat-shielding film according to claim 1, wherein the coating layer comprises a siloxane polymer.

5. The light-absorbing and heat-shielding film according to claim 1, wherein the coating layer comprises a polymer of silsesquioxane.

6. The coating layer comprises a polymer of silsesquioxane, and the silsesquioxane is [R1(SiO １．５ ) ｎ The light-absorbing heat-shielding film according to claim 1, wherein when represented by the composition formula ], R1 is a polymerizable group.

7. The coating layer comprises a polymer of silsesquioxane, and the silsesquioxane is [R1(SiO １．５ ) ｎ The light-absorbing heat-shielding film according to claim 1, wherein when represented by the compositional formula ], R1 is at least one polymerizable group selected from the group consisting of acryloyl group, methacryloyl group, oxetanyl group and epoxy group.

8. The metal oxide layer comprises aluminum oxide, The coating layer contains a polymer of silsesquioxane, The light-absorbing heat-shielding film according to claim 1, wherein the thickness of the coating layer is 20 nm or more and 180 nm or less.

9. The light-absorbing and heat-shielding film according to claim 1, wherein the coating layer comprises a fluororesin or an acrylic resin.

10. The light-absorbing and heat-shielding film according to claim 1, wherein the coating layer comprises a fluoroolefin polymer.

11. The light-absorbing and heat-shielding film according to claim 1, wherein the metal component of the metal oxide layer is different from the metal component of the metal layer.

12. The light-absorbing heat-shielding film according to claim 1, wherein the metal oxide layer comprises aluminum oxide.

13. The light-absorbing heat-shielding film according to claim 1, wherein the metal layer comprises one selected from the group consisting of nickel, chromium, and zinc.

14. The light-absorbing heat-shielding film according to claim 8, wherein the metal layer contains nickel.

15. The light-absorbing heat-shielding film according to claim 1, wherein the metal layer includes a second structure comprising a plurality of protrusions, the arithmetic mean roughness Ra of the main surface on which the second structure is provided is 0.1 μm or more and 5 μm or less, and the maximum height Rz of the main surface on which the second structure is provided is 1 μm or more and 10 μm or less.

16. The light-absorbing heat-shielding film according to claim 15, wherein the first structure is formed on the upper surface of the second structure.

17. The light-absorbing and heat-shielding film according to claim 1, wherein the metal oxide layer fills the spaces between the protrusions included in the first structure and covers the protrusions of the first structure.

18. A light-absorbing and heat-shielding member comprising a light-absorbing and heat-shielding film according to any one of claims 1 to 17, wherein a base material is provided on the side opposite to the side having the first structure.

19. The device comprises a heating element and a light-absorbing heat-shielding film according to any one of claims 1 to 17, An article in which the light-absorbing heat-shielding film shields the heat from a heating element.

20. A step of preparing a mold having a shape including a plurality of protrusions, A step of forming a metal layer having a structure including a plurality of protrusions on the mold, in which the shape including the plurality of protrusions is transferred, A step of separating the metal layer from the mold, After the separation step, a step of forming a coating layer on the structure including the multiple protrusions of the metal layer. A method for manufacturing a light-absorbing heat-shielding film containing [the specified material].

21. The method for manufacturing a light-absorbing heat-shielding film according to claim 20, wherein the mold comprises a substrate and a metal oxide layer having a shape including the plurality of protrusions on the substrate.

22. The method for manufacturing a light-absorbing heat-shielding film according to claim 21, wherein at least a portion of the metal oxide layer adheres to the metal layer separated from the mold.

23. The method for manufacturing a light-absorbing heat-shielding film according to claim 22, wherein the coating layer covers at least a portion of the metal oxide layer attached to the metal layer.

24. The method for manufacturing a light-absorbing heat-shielding film according to claim 20, wherein the coating layer is formed by applying a liquid.

25. The method for producing a light-absorbing heat-shielding film according to claim 24, wherein the liquid comprises silsesquioxane.

26. The method for producing a light-absorbing heat-shielding film according to claim 24, wherein the liquid comprises a fluororesin.

27. The method for manufacturing a light-absorbing heat-shielding film according to claim 20, wherein the shape including the plurality of protrusions is formed by immersing a film containing aluminum in hot water.

28. The method for manufacturing a light-absorbing heat-shielding film according to claim 20, wherein at least a portion of the metal oxide layer attached to the metal layer is removed from the metal layer before the step of forming the coating layer.

29. A step of preparing a mold having a shape including a plurality of protrusions, A step of forming a metal layer having a structure including a plurality of protrusions on the mold, in which the shape including the plurality of protrusions is transferred, A step of separating the metal layer from the mold, After the separation step, a step of forming a coating layer on the structure including the multiple protrusions of the metal layer, A step of bonding the substrate to the side of the metal layer opposite to the side on which the shape including the plurality of protrusions is transferred. A method for manufacturing a light-absorbing and heat-shielding member.

30. A method for manufacturing a light-absorbing and heat-shielding member according to claim 29, wherein the step of bonding the substrate is performed after the step of forming the metal layer and before the step of separating.

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