Multi-layered thin film, and laminate

Abstract

To provide a multi-layered thin film excellent in wet heat resistance, and having infrared-shielding function, and a laminate having the multi-layered thin film.SOLUTION: A multilayered thin film is obtained by laminating a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film in this order. The first, and the second metal oxide thin films are preferably dialuminum trioxide thin films. The ratio of a fluorine atom in the first and second fluorine-doped cerium dioxide thin films is 1-60 at% in an atomic ratio when a total sum of atoms in the fluorine-doped cerium dioxide thin film is 100 at%.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a multilayer thin film and a laminate having the multilayer thin film. More specifically, the present invention relates to a multilayer thin film having an infrared shielding function and a laminate having the multilayer thin film. [Background technology]

[0002] Conventionally, in order to make the space comfortable with less energy, transparent films having infrared shielding function are often attached to window glass of buildings and roof windows of automobiles. Such transparent films having infrared shielding function include those in which fine particles such as tin-doped indium oxide, antimony-doped tin oxide, and cesium-doped tungsten oxide are contained in any layer of the film, and infrared shielding function is realized by mainly absorbing infrared rays; and those in which a metal thin film such as gold, silver, copper, and palladium is formed as a constituent layer of the film, and infrared shielding function is realized by mainly reflecting infrared rays. In the latter film, transparent thin films such as silicon, silicon oxide, and titanium oxide are often provided on both sides of the metal thin film for the purpose of protecting the metal thin film. However, metal thin films such as gold, silver, copper, and palladium, especially silver thin films, have the disadvantage of insufficient environmental stability, especially wet heat resistance, even if they are protected by providing transparent thin films on both sides. Therefore, it has been proposed to use a cerium (IV) oxide thin film as a transparent thin film provided on both sides of a metal thin film (Patent Document 1). However, when the present inventors conducted further experiments, it was found that a multilayer thin film formed by laminating a cerium (IV) oxide thin film, a silver thin film, and a cerium (IV) oxide thin film in this order has the disadvantage that the cerium (IV) oxide thin film is prone to cracking in a high-temperature and high-humidity environment (see Patent Application No. 2023-042695 by the present inventors). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-085047 A [Patent Document 2] JP 2022-186664 A [Patent Document 3] JP 2021-073161 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a multilayer thin film having an infrared shielding function and good resistance to moist heat, and a laminate having the multilayer thin film. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have found that the above object can be achieved by using a specific multilayer thin film.

[0006] That is, the various aspects of the present invention are as follows. [1]. A multilayer thin film comprising a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film stacked in this order. [2]. The multilayer thin film according to item [1], wherein a ratio of fluorine atoms in the first fluorine-doped cerium dioxide thin film is, in atomic ratio, 1 to 60 at %, with a total of atoms in the first fluorine-doped cerium dioxide thin film being 100 at %, and a ratio of fluorine atoms in the second fluorine-doped cerium dioxide thin film is, in atomic ratio, 1 to 60 at %, with a total of atoms in the second fluorine-doped cerium dioxide thin film being 100 at %. [3]. The multilayer thin film according to item [1], wherein at least one thin film selected from the group consisting of the first metal oxide thin film and the second metal oxide thin film is a thin film of aluminum trioxide. [4]. The multilayer thin film according to item [1], wherein at least one thin film selected from the group consisting of the first metal oxide thin film and the second metal oxide thin film is a cerium dioxide thin film. [5]. Item 1. The multilayer thin film according to item 1, wherein the metal thin film is a copper thin film. [6]. Item 1. The multilayer thin film according to item 1, wherein the metal thin film is an aluminum thin film. [7]. Item 1. The multilayer thin film according to item 1, wherein the metal thin film is a silver thin film. [8]. A laminate having the multilayer thin film according to any one of items [1] to [7] on a part or all of the surfaces of a substrate. [9]. An article having the multilayer thin film according to any one of items [1] to [7].

[10] . A method for producing a multilayer thin film in which a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film are laminated in this order, the step of forming at least one thin film selected from the group consisting of the first fluorine-doped cerium dioxide thin film and the second fluorine-doped cerium dioxide thin film using a sputtering device and using a cerium dioxide target and an organic fluorine compound gas, comprising the steps of: (1) mounting the cerium dioxide target on a target installation jig of the sputtering device; (2) changing the internal temperature of a sputtering chamber of the sputtering device to a predetermined temperature; (3) a substep of reducing the pressure in the sputtering chamber of the sputtering apparatus to a predetermined pressure a; (4) a substep of forming a fluorine-doped cerium dioxide thin film by applying power to the cerium dioxide target and sputtering, wherein the method for producing the multilayer thin film includes the steps of: (1) reducing the pressure in the sputtering chamber to a predetermined pressure a; (2) introducing a mixed gas of a sputtering gas and the organofluorine compound gas into the sputtering chamber of the sputtering apparatus so that the pressure in the sputtering chamber becomes a predetermined pressure b; and (3) providing a mixed gas of the sputtering gas and the organofluorine compound gas into the sputtering chamber of the sputtering apparatus so that the pressure in the sputtering chamber becomes a predetermined pressure b; Effect of the Invention

[0007] The multilayer thin film of the present invention has an infrared shielding function and good moist heat resistance. A preferred multilayer thin film of the present invention has good infrared shielding function and transparency, and good moist heat resistance. Therefore, the multilayer thin film of the present invention and a laminate having the multilayer thin film can be suitably used in articles requiring an infrared shielding function. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] As used herein, the term "inorganic material" includes mixtures containing two or more inorganic materials, and the term "organic compound" includes mixtures containing two or more organic compounds.

[0009] In this specification, the term "resin" is used to include a resin mixture containing two or more resins, and a resin composition containing components other than resin.

[0010] In this specification, the term "film" is used interchangeably or interchangeably with "sheet." In this specification, the terms "film" and "sheet" are used for those that can be industrially wound into a roll. The term "plate" is used for those that cannot be industrially wound into a roll. In addition, in this specification, laminating a certain layer and another layer in order includes both directly laminating the layers and laminating the layers with one or more other layers, such as an anchor coat, interposed between the layers.

[0011] In this specification, the term "more than" in relation to a numerical range means a certain number or more than a certain number. For example, 20% or more means 20% or more than 20%. The term "less than" in relation to a numerical range means a certain number or less than a certain number. For example, 20% or less means 20% or less than 20%. Furthermore, the symbol "~" in relation to a numerical range means a certain number, more than a certain number and less than another certain number, or another certain number. Here, the other certain number is a number larger than the certain number. For example, 10 to 90% means 10%, more than 10% and less than 90%, or 90%. Furthermore, the upper and lower limits of the numerical range can be arbitrarily combined, and an embodiment in which the values ​​are arbitrarily combined can be read. For example, from a statement regarding the numerical range of a certain characteristic such as "usually 10% or more, preferably 20% or more. On the other hand, it is usually 40% or less, preferably 30% or less" or "usually 10 to 40%, preferably 20 to 30%," it can be read that the numerical range of the certain characteristic is 10 to 40%, 20 to 30%, 10 to 30%, or 20 to 40% in one embodiment.

[0012] Other than in the examples, or where otherwise specified, all numerical values ​​used in the specification and claims should be understood to be modified by the term "about." Without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical value should be construed in light of the number of significant digits and by applying ordinary rounding techniques.

[0013] In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include substantially the same state in addition to their strict meanings.

[0014] 1. Multi-layer thin film: The multilayer thin film of the present invention is a multilayer thin film in which a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film are laminated in this order. In one typical embodiment, the multilayer thin film of the present invention may be a multilayer thin film in which the first fluorine-doped cerium dioxide thin film, the first metal oxide thin film, the metal thin film, the second metal oxide thin film, and the second fluorine-doped cerium dioxide thin film are directly laminated in this order.

[0015] Although not intending to be bound by theory, the reason why the multilayer thin film of the present invention exhibits good moist heat resistance is considered as follows. By comparing Examples 1 and 2, and Examples 5 and 6 of the experimental examples of Patent Application No. 2023-042695 by the present inventors, the following considerations a and b can be made. Consideration a: When a metal oxide thin film is directly formed on the surface of a metal thin film, even a slight migration of the metal occurs, and if aggregates are generated and the volume changes, the film cannot withstand and cracks occur. Consideration b: On the other hand, a fluorine-doped cerium dioxide thin film can withstand volume changes because it is given flexibility by fluorine doping. However, when a fluorine-doped cerium dioxide thin film is directly formed on the surface of a metal thin film, or when a metal thin film is directly formed on the surface of a fluorine-doped cerium dioxide thin film, it is assumed that the metal thin film may be modified by fluorine atoms, causing an inconvenience that causes a decrease in infrared shielding function. On the other hand, such inconveniences do not occur with a metal oxide thin film. In view of this, the multilayer thin film of the present invention is formed by laminating a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film in this order, i.e., by forming metal oxide thin films on both sides of a metal thin film, the metal thin film is protected from environmental loads such as high temperature and high humidity, and by providing a metal oxide thin film between the metal thin film and the fluorine-doped cerium dioxide thin film, the possibility of the metal thin film being modified by fluorine atoms and thus reducing the infrared shielding function is eliminated. Furthermore, by forming a fluorine-doped cerium dioxide thin film on the surface of the metal oxide thin film to directly protect the metal oxide thin film, the metal thin film is also indirectly protected, thereby suppressing the occurrence of cracks.

[0016] Hereinafter, each layer of the multilayer thin film of the present invention will be described. Hereinafter, when simply referring to a "fluorine-doped cerium dioxide thin film", it means "the first fluorine-doped cerium dioxide thin film and the second fluorine-doped cerium dioxide thin film". When simply referring to a "metal oxide thin film", it means "the first metal oxide thin film and the second metal oxide thin film".

[0017] 1-1. Fluorine-doped cerium dioxide thin film: The fluorine-doped cerium dioxide thin film is a thin film containing atoms derived from cerium dioxide (cerium (IV) oxide, CeO2) and atoms derived from an organic fluorine compound. As described above, without intending to be bound by theory, it is considered that the fluorine-doped cerium dioxide thin film protects the metal thin film and the metal oxide thin film from environmental loads such as high temperature and high humidity, and directly protects the metal oxide thin film. In a typical embodiment, the fluorine-doped cerium dioxide thin film may include a compound containing atoms derived from the cerium dioxide and atoms derived from the organic fluorine compound, and in which the cerium dioxide is modified with atoms derived from the organic fluorine compound.

[0018] The ratio of fluorine atoms in the fluorine-doped cerium dioxide thin film can be appropriately selected in consideration of the use of the multilayer thin film. The ratio of fluorine atoms in the fluorine-doped cerium dioxide thin film may be, in terms of atomic ratio, usually 1 at% or more, preferably 4 at% or more, more preferably 7 at% or more, even more preferably 10 at% or more, even more preferably 12 at% or more, and most preferably 16 at% or more, with the sum of atoms in the fluorine-doped cerium dioxide thin film being 100 at%, from the viewpoint of wet heat resistance. On the other hand, the ratio of fluorine atoms in the fluorine-doped cerium dioxide thin film may be usually 60 at% or less, preferably 55 at% or less, more preferably 50 at% or less, even more preferably 45 at% or less, and most preferably 40 at% or less, from the viewpoint of transparency.

[0019] The proportion of fluorine atoms in the fluorine-doped cerium dioxide thin film can be determined by X-ray photoelectron spectroscopy (hereinafter sometimes referred to as "XPS analysis"). XPS analysis can be performed, for example, using an XPS analyzer and aluminum Kα rays or magnesium Kα rays as X-rays. For XPS analysis, the following references can be referred to. Reference: MPSeah and WADerch, Surface and Interface Analysis 1, 2 (1979)

[0020] Fig. 1 is an example of a spectrum obtained by XPS analysis of a fluorine-doped cerium dioxide thin film in the energy region of -10 to 1350 eV. The spectrum shows a peak at around 290 eV belonging to the carbon 1s orbital (C1s), a peak at around 530 eV belonging to the oxygen 1s orbital (O1s), a peak at around 680 eV belonging to the fluorine 1s orbital (F1s), and a peak at around 880 eV belonging to the cerium 3d orbital (Ce3d), and the atomic ratio of each element can be calculated from the area ratio of these peaks. In the case of the fluorine-doped cerium dioxide thin film in Fig. 1, the calculated carbon content was 30 at%, oxygen 19 at%, fluorine 39 at%, and cerium 12 at%.

[0021] The ratio of fluorine atoms in the first fluorine-doped cerium dioxide thin film and the ratio of fluorine atoms in the second fluorine-doped cerium dioxide thin film may be the same as or different from each other.

[0022] The fluorine-doped cerium dioxide thin film is formed by using the cerium dioxide and the organic fluorine compound. The method for forming the fluorine-doped cerium dioxide thin film by using the cerium dioxide and the organic fluorine compound is not particularly limited. A preferred method for forming the fluorine-doped cerium dioxide thin film by using the cerium dioxide and the organic fluorine compound is a sputtering method.

[0023] When the fluorine-doped cerium dioxide thin film is formed by sputtering, the cerium dioxide may be of high purity, where high purity means a purity of 3N (99.9%) or higher, preferably 4N (99.99%) or higher.

[0024] Preferred methods for forming the fluorine-doped cerium dioxide thin film by sputtering include, for example, the method disclosed in JP 2022-186664 A and the method disclosed in paragraphs 0058 to 0076 of JP 2019-123872 A as a method for producing an organic-inorganic hybrid film by sputtering. All of the disclosures in JP 2022-186664 A and JP 2019-123872 A are incorporated herein by reference.

[0025] When the fluorine-doped cerium dioxide thin film is formed using the method disclosed in JP 2022-186664 A, a gas of an organic fluorine compound is used as the organic fluorine compound. Examples of such organic fluorine compounds include compounds having a structure in which one or more hydrogen atoms of saturated hydrocarbons such as tetrafluoromethane, trifluoromethane, difluoromethane, fluoromethane, and 1,1,1,2-tetrafluoroethane are substituted with fluorine atoms, and which are gaseous under standard conditions (temperature 25°C, pressure 100 KPa); compounds having a structure in which one or more hydrogen atoms of unsaturated hydrocarbons are substituted with fluorine atoms, such as compounds having a structure in which one or more hydrogen atoms of α-olefins such as tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene, pentafluoropropylene, tetrafluoropropylene, trifluoropropylene, and chlorotrifluoroethylene are substituted with fluorine atoms, and which are gaseous under standard conditions (temperature 25°C, pressure 100 KPa); and mixtures thereof. Among these, tetrafluoromethane is preferred as the organic fluorine compound.

[0026] In the case of forming the fluorine-doped cerium dioxide thin film using the method disclosed in paragraphs 0058 to 0076 of JP 2019-123872 A as a case of producing an organic-inorganic hybrid film by a sputtering method, the organic fluorine compound used is preferably a fluorine-based resin from the viewpoint of manufacturability of a molded body as a target. The fluorine-based resin is a resin containing a constituent unit derived from a monomer containing a fluorine atom (a compound having a structure in which one or more hydrogen atoms are substituted with fluorine atoms and having polymerizability). Examples of the fluorine-based resin include polytetrafluoroethylene, polyhexafluoropropylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, chlorotrifluoroethylene-ethylene copolymer, and polychlorotrifluoroethylene. Among these, the fluorine-based resins are preferably polytetrafluoroethylene and polyvinylidene fluoride.

[0027] The thickness of the fluorine-doped cerium dioxide thin film can be appropriately selected in consideration of the use of the multilayer thin film. The thickness of the fluorine-doped cerium dioxide thin film may be usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 20 nm or more, from the viewpoint of reliably obtaining the function of protecting the metal thin film and the metal oxide thin film from environmental loads such as high temperature and high humidity. On the other hand, the thickness of the fluorine-doped cerium dioxide thin film may be usually 500 nm or less, preferably 400 nm or less, more preferably 300 nm or less, even more preferably 200 nm or less, and most preferably 150 nm or less, from the viewpoint of crack resistance.

[0028] The thickness of the first fluorine-doped cerium dioxide thin film and the thickness of the second fluorine-doped cerium dioxide thin film may be the same as or different from each other.

[0029] 1-2. Metal oxide thin films: Without intending to be bound by theory, it is believed that the metal oxide thin film directly protects the metal thin film from environmental loads such as high temperature and high humidity, as described above, and, by being present between the metal thin film and the fluorine-doped cerium dioxide thin film, functions to eliminate the possibility of the metal thin film being modified by fluorine atoms, resulting in a decrease in its infrared shielding function.

[0030] The metal oxide thin film is a thin film of oxide of metal atoms (including semimetals such as boron, silicon, and germanium). Examples of the metal oxide thin film include thin films of oxides of metal atoms such as boron, aluminum, gallium, indium, silicon, germanium, tin, titanium, zirconium, hafnium, niobium, yttrium, and cerium, and thin films of composite oxides of these metal atoms (for example, tin-doped indium oxide). Among these, the metal oxide thin film may be a thin film containing at least one selected from the group consisting of aluminum trioxide and cerium dioxide, more preferably a thin film containing aluminum trioxide, from the viewpoint of resistance to moist heat.

[0031] The method for forming the metal oxide thin film is not particularly limited, and examples of the method for forming the metal oxide thin film include sputtering, vacuum deposition, and electron beam deposition.

[0032] The thickness of the metal oxide thin film can be appropriately selected in consideration of the use of the multilayer thin film. From the viewpoint of wet heat resistance, the thickness of the metal oxide thin film may be usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, even more preferably 15 nm or more, and most preferably 20 nm or more. On the other hand, from the viewpoint of transparency, the thickness of the metal oxide thin film may be preferably 50 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less, and most preferably 25 nm or less.

[0033] 1-2. Metal thin film layer The metal thin film acts to exhibit an infrared shielding function. The metal thin film may be any metal thin film capable of exhibiting an infrared shielding function, and may exhibit the infrared shielding function by mainly reflecting infrared rays, or may exhibit the infrared shielding function by mainly absorbing infrared rays.

[0034] Examples of the metal thin film include thin films of metals such as silver, copper, aluminum, indium, tin, chromium, nickel, gold, palladium, platinum, and alloys thereof. Of these, silver is preferred as the metal thin film from the viewpoints of reflectivity in the infrared region (high infrared shielding function) and transmittance (transparency) in the visible light region. Of these, copper and aluminum are preferred as the metal thin film from the viewpoints of environmental stability, particularly resistance to moist heat.

[0035] The method for forming the metal thin film is not particularly limited, and examples of the method for forming the metal thin film include sputtering, vacuum deposition, and electron beam deposition.

[0036] The thickness of the metal thin film can be appropriately selected in consideration of the use of the multilayer thin film. From the viewpoint of infrared shielding function, the thickness of the metal thin film may be usually 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, even more preferably 7 nm or more, and most preferably 10 nm or more. On the other hand, from the viewpoint of transparency, the thickness of the metal thin film may be preferably 50 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less, and most preferably 20 nm or less.

[0037] 2.Laminate: The laminate of the present invention is a laminate having the multilayer thin film of the present invention on a part or all of the surfaces of a substrate. Hereinafter, the laminate of the present invention will be described assuming that the layer that is closest to the substrate among the layers constituting the multilayer thin film of the present invention is the first fluorine-doped cerium dioxide thin film.

[0038] The substrate can be appropriately selected in consideration of the application of the laminate. The surface of the substrate on which the multilayer thin film is laminated may be smooth or have a three-dimensional shape. Here, the three-dimensional shape means a shape that includes a non-planar shape such as unevenness in at least a part thereof. In one typical embodiment, the substrate is a film, a sheet, or a plate.

[0039] Examples of the substrate include inorganic glass films, inorganic glass sheets, and inorganic glass plates such as soda lime glass, borosilicate glass, and quartz glass.

[0040] Examples of the substrate include resin films, resin sheets, or resin plates such as cellulose ester resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate; cyclic hydrocarbon resins such as ethylene norbornene copolymers; acrylic resins such as polymethyl methacrylate, polyethyl methacrylate, and vinylcyclohexane-methyl (meth)acrylate copolymers; aromatic polycarbonate resins; polyolefin resins such as polypropylene and 4-methyl-pentene-1; polyamide resins; polyarylate resins; polymeric urethane acrylate resins; and polyimide resins. These resin films include non-stretched films, uniaxially stretched films, and biaxially stretched films. These resin films also include laminated resin films in which one or more of these are laminated in two or more layers. These resin sheets also include non-stretched sheets, uniaxially stretched sheets, and biaxially stretched sheets. These resin sheets also include laminated resin sheets in which one or more of these are laminated in two or more layers. These resin plates include laminated resin plates in which one or more of these materials are laminated in two or more layers.

[0041] The substrate may have a functional layer. An embodiment of the substrate having a functional layer may be, for example, the inorganic glass film, the inorganic glass sheet, the inorganic glass plate, the resin film, the resin sheet, or the resin plate, on at least one side of which a functional layer is used, and the surface on the functional layer side or the surface opposite to the functional layer is a laminated surface with the multilayer thin film. Examples of the functional layer include those having functions such as hardness improvement function, anchor function, low refractive index, high refractive index, ultraviolet shielding, electromagnetic wave shielding, electromagnetic wave reflection, visibility control (blindness), and viewing angle control. The functional layer may be a coating film (including a hard coat) formed using a paint, or may be a film formed by a dry coating method such as a sputtering method, a vacuum deposition method, or a chemical vapor deposition method.

[0042] When the inorganic glass film, the inorganic glass sheet, or the inorganic glass plate is used as the substrate, the thickness of the inorganic glass film, the inorganic glass sheet, or the inorganic glass plate can be appropriately selected in consideration of the use of the laminate. The thickness of the inorganic glass film, the inorganic glass sheet, or the inorganic glass plate may be usually 20 μm or more, preferably 50 μm or more, from the viewpoint of the handleability of the laminate. Also, from the viewpoint of the impact resistance of the inorganic glass, it may be preferably 1 mm or more, more preferably 1.5 mm or more. On the other hand, from the viewpoint of weight reduction of the article using the laminate, it may be usually 6 mm or less, preferably 4.5 mm or less, more preferably 3 mm or less.

[0043] When the resin film, the resin sheet, or the resin plate is used as the substrate, the thickness of the resin film, the resin sheet, or the resin plate can be appropriately selected in consideration of the use of the laminate. The thickness of the resin film, the resin sheet, or the resin plate may be usually 20 μm or more, preferably 50 μm or more, from the viewpoint of the handleability of the laminate. When the laminate is used for an application that does not require high rigidity, it may be usually 250 μm or less, preferably 150 μm or less, from the viewpoint of economic efficiency. When the laminate is used for an application that requires high rigidity, it may be usually 300 μm or more, preferably 500 μm or more, more preferably 600 μm or more, from the viewpoint of maintaining rigidity. In addition, it may be usually 1500 μm or less, preferably 1200 μm or less, more preferably 1000 μm or less, from the viewpoint of responding to the demand for thinning of the article using the laminate.

[0044] The substrate may be transparent, opaque, colored transparent, or colored opaque (having a concealing property), and can be appropriately selected in consideration of the use of the laminate.

[0045] The laminate of the present invention has the first fluorine-doped cerium dioxide thin film laminated on a part or all of the surfaces of the substrate, directly or via one or more other layers such as an anchor coat. The first fluorine-doped cerium dioxide thin film was described in "1-1. Fluorine-doped cerium dioxide thin film" in "1. Multilayer thin film".

[0046] The laminate of the present invention further comprises the first metal oxide thin film, the metal thin film, the second metal oxide thin film, and the second fluorine-doped cerium dioxide thin film laminated in this order on the surface of the first fluorine-doped cerium dioxide thin film. In one typical embodiment of the laminate of the present invention, the first metal oxide thin film, the metal thin film, the second metal oxide thin film, and the second fluorine-doped cerium dioxide thin film are further laminated in this order directly on the surface of the first fluorine-doped cerium dioxide thin film.

[0047] The first metal oxide thin film and the second metal oxide thin film were described in "1. Multilayer thin film" under "1-2. Metal oxide thin film." The metal thin film was described in "1. Multilayer thin film" under "1-3. Metal thin film." The second fluorine-doped cerium dioxide thin film was described in "1. Multilayer thin film" under "1-1. Fluorine-doped cerium dioxide thin film."

[0048] The laminate of the present invention may further have a topcoat layer on the surface of the second fluorine-doped cerium dioxide thin film, if desired. The topcoat layer may be a coating film (including a hard coat) formed using a paint, or a film formed by a dry coating method such as a sputtering method, a vacuum deposition method, or a chemical vapor deposition method. The thickness of the topcoat layer may be preferably about 0.01 to 5 μm, more preferably about 0.05 to 1 μm.

[0049] 3. Manufacturing method of laminate: An example of an embodiment of a method for producing the laminate of the present invention, in which the first fluorine-doped cerium dioxide thin film, the first metal oxide thin film, the metal thin film, the second metal oxide thin film, and the second fluorine-doped cerium dioxide thin film are directly laminated in this order, using a batch-type sputtering apparatus as conceptually shown in FIG. 2 will be described.

[0050] 3-1. First, deposition of fluorine-doped cerium dioxide thin film: First, the first fluorine-doped cerium dioxide thin film is formed on one surface of the substrate 4 .

[0051] First, the cerium dioxide target 1 is mounted on the target mounting jig 2. By mounting the cerium dioxide target 1 on the target mounting jig 2, the cerium dioxide target 1 is connected to a power source (not shown). In addition, a flow path for a medium such as water is provided inside the target mounting jig 2, so that the temperature of the cerium dioxide target 1 can be controlled to a predetermined temperature.

[0052] Next, the substrate 4 is attached to the sputtering table 3 and rotated at a predetermined rotation speed. The predetermined rotation speed of the sputtering table 3 may be usually 1 to 1000 rpm, preferably 2 to 50 rpm. During the formation of the first fluorine-doped cerium dioxide thin film, the rotation speed may be constant, or may be changed as desired.

[0053] Next, the inside of the sputtering chamber 5 is evacuated from the exhaust port 6 by an exhaust device (not shown) to make the inside of the sputtering chamber 5 at a pressure equal to or lower than a predetermined pressure a during film formation. -5 ~10 -2 Pa, preferably 10 -4 ~5×10 -3 It may be on the order of Pa.

[0054] Next, a mixed gas of the sputtering gas and the organic fluorine compound gas is introduced into the sputtering chamber 5 from the sputtering gas inlet 7 so that the inside of the sputtering chamber 5 is at a predetermined pressure b during film formation. At this time, the sputtering gas and the organic fluorine compound gas may be prepared separately and introduced while the two gas flows are joined and mixed, or the mixed gas of the sputtering gas and the organic fluorine compound gas may be prepared in advance and introduced. Also, the amount of the mixed gas introduced may be fixed and the opening of the exhaust port 6 may be feedback-controlled to keep the sputtering pressure constant.

[0055] The mixing ratio of the sputtering gas and the gas of the organic fluorine compound can be appropriately determined from the viewpoint of making the composition of the first fluorine-doped cerium dioxide thin film (the ratio of fluorine atoms in the first fluorine-doped cerium dioxide thin film) a desired composition. The mixing ratio of the sputtering gas and the gas of the organic fluorine compound (volume of the sputtering gas / volume of the gas of the organic compound) may be usually 95 / 5 to 99.99 / 0.01, preferably 97 / 3 to 99.9 / 0.1, more preferably 98 / 2 to 99.7 / 0.3, even more preferably 98.3 / 1.7 to 99.5 / 0.5, and most preferably 98.6 / 1.4 to 99.3 / 0.7, depending on the type of the gas of the organic fluorine compound.

[0056] The sputtering gas is not particularly limited as long as it is a gas that can be used for sputtering, and may be any known sputtering gas. Examples of the sputtering gas include noble gases such as argon and krypton, and mixtures of these gases with oxygen and nitrogen. The sputtering gas may preferably be noble gases such as argon and krypton.

[0057] The above-mentioned organic fluorine compound gas is not limited to an organic fluorine compound gas that is gaseous under standard conditions (temperature 25°C, pressure 100 KPa). The above-mentioned organic fluorine compound gas may be an organic fluorine compound gas that becomes gaseous by heating and / or reducing pressure. In this case, it goes without saying that the gaseous state is adjusted to a predetermined temperature and pressure before use. In this case, it is also preferable that the temperature inside the sputtering chamber 5 is also adjusted to a predetermined temperature.

[0058] Examples of such organic fluorine compounds include compounds having a structure in which one or more hydrogen atoms of saturated hydrocarbons such as tetrafluoromethane, trifluoromethane, difluoromethane, fluoromethane, and 1,1,1,2-tetrafluoroethane are substituted with fluorine atoms, and which are gaseous under standard conditions (temperature 25°C, pressure 100 KPa); compounds having a structure in which one or more hydrogen atoms of unsaturated hydrocarbons are substituted with fluorine atoms, such as compounds having a structure in which one or more hydrogen atoms of α-olefins such as tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene, pentafluoropropylene, tetrafluoropropylene, trifluoropropylene, and chlorotrifluoroethylene are substituted with fluorine atoms, and which are gaseous under standard conditions (temperature 25°C, pressure 100 KPa); and mixtures thereof. Among these, tetrafluoromethane is preferred as the organic fluorine compound.

[0059] As the gas of the above organic fluorine compound, one of these gases or a mixture of two or more of them can be used.

[0060] The predetermined pressure b (sputtering pressure) in the sputtering chamber 5 during the above film formation may be usually 0.05 to 5 Pa, preferably 0.1 to 1 Pa, from the viewpoint of stabilizing the discharge and enabling continuous film formation.

[0061] Next, a predetermined power is applied to the cerium dioxide target 1 to cause discharge, and when the discharge state becomes stable, the shutter 8 is opened to sputter the cerium dioxide target 1, forming the first fluorine-doped cerium dioxide thin film on the surface of the substrate 4. By keeping the shutter 8 closed until the discharge state becomes stable, it is possible to prevent the above-mentioned contaminants from adhering to the surface of the substrate 4 during pre-sputtering (an operation for removing contaminants such as dirt and water on the surface of the cerium dioxide target 1 (by blowing them away by applying power)). The power applied here is usually an AC power, preferably a high-frequency AC power, since the target must have a sufficiently high conductivity in order to use a DC current.

[0062] The composition of the first fluorine-doped cerium dioxide thin film (the proportion of fluorine atoms in the first fluorine-doped cerium dioxide thin film) can be adjusted to a desired composition by adjusting the power input to the cerium dioxide target 1, the mixing ratio of the sputtering gas and the organofluorine compound gas, and the flow rate of the mixed gas of the sputtering gas and the organofluorine compound gas (predetermined pressure b (sputtering pressure) in the sputtering chamber 5 during film formation). The relationship between the input power amount, the mixing ratio, and the flow rate of the mixed gas and the composition can be determined by conducting a preliminary experiment.

[0063] The thickness of the first fluorine-doped cerium dioxide thin film can be adjusted to a desired thickness by adjusting the power input to the cerium dioxide target 1, the mixture ratio of the sputtering gas and the organofluorine compound gas, the flow rate of the mixed gas of the sputtering gas and the organofluorine compound gas (predetermined pressure b (sputtering pressure) in the sputtering chamber 5 during film formation), and the film formation time. The relationship between the input power amount, the mixture ratio, the flow rate of the mixed gas, the film formation time, and the film thickness can be determined by a preliminary experiment.

[0064] 3-2. Deposition of the first metal oxide thin film: Next, the first metal oxide thin film is formed directly on the surface of the first fluorine-doped cerium dioxide thin film of the intermediate laminate a having the first fluorine-doped cerium dioxide thin film on one surface of the substrate 4 .

[0065] First, a metal oxide target is mounted on the target mounting jig 2. By mounting the metal oxide target on the target mounting jig 2, the metal oxide target is connected to a power source (not shown).

[0066] Next, the intermediate laminate a is attached to the sputtering table 3 so that the surface on the side of the first fluorine-doped cerium dioxide thin film becomes the deposition surface, and is rotated at a predetermined rotation speed. The predetermined rotation speed of the sputtering table 3 may be usually 1 to 1000 rpm, preferably 2 to 50 rpm. The rotation speed may be constant during deposition of the first metal oxide thin film, or may be changed as desired.

[0067] Next, the inside of the sputtering chamber 5 is evacuated from the exhaust port 6 by an exhaust device (not shown) to make the pressure in the sputtering chamber 5 at the time of film formation equal to or lower than a predetermined pressure a'. -5 ~10 -2 Pa, preferably 10 -4 ~5×10 -3 It may be on the order of Pa.

[0068] Next, sputtering gas is introduced into the sputtering chamber 5 from the sputtering gas inlet 7 so that the pressure in the sputtering chamber 5 becomes a predetermined pressure b' during film formation. The amount of the sputtering gas introduced may be fixed, and the opening of the exhaust port 6 may be feedback-controlled to keep the sputtering pressure constant. The sputtering gas is not particularly limited as long as it is a gas that can be used for sputtering, and may be any known sputtering gas. The sputtering gas may be a noble gas, such as argon or krypton, preferably.

[0069] The predetermined pressure b' (sputtering pressure) in the sputtering chamber 5 during the above film formation may be usually 0.05 to 5 Pa, preferably 0.1 to 1 Pa, from the viewpoint of stabilizing the discharge and enabling continuous film formation.

[0070] Next, a predetermined power is applied to the metal oxide target to cause discharge, and when the discharge state becomes stable, the shutter 8 is opened to sputter the metal oxide target, and the metal oxide thin film is formed directly on the surface of the first fluorine-doped cerium dioxide thin film of the intermediate laminate a. In addition, by keeping the shutter 8 closed until the discharge state becomes stable, it is possible to prevent the adhesion of the contaminants on the surface of the intermediate laminate a during pre-sputtering (the operation of removing contaminants such as dirt and water on the surface of the intermediate laminate a (by applying power to blow them away)). Here, the power applied may be DC power or AC power. It can be appropriately selected taking into consideration the conductivity of the metal oxide used. The power applied may be AC ​​power, preferably high-frequency AC power, since the target needs to have a sufficiently high conductivity to use a DC current.

[0071] The thickness of the first metal oxide thin film can be adjusted to a desired thickness by adjusting the power input to the metal oxide target, the flow rate of the sputtering gas (predetermined pressure b' (sputtering pressure) in the sputtering chamber 5 during film formation), and the film formation time. The relationship between the amount of input power, the flow rate of the sputtering gas, the film formation time, and the film thickness can be determined by conducting a preliminary experiment.

[0072] 3-3. Metal thin film deposition: Next, the above-mentioned metal thin film is formed directly on the surface of the first metal oxide thin film of an intermediate laminate b having the above-mentioned first fluorine-doped cerium dioxide thin film and the above-mentioned first metal oxide thin film in that order on one surface of a substrate 4.

[0073] First, a metal target is mounted on the target mounting jig 2. By mounting the metal target on the target mounting jig 2, the metal target is connected to a power source (not shown).

[0074] Next, the intermediate laminate b is attached to the sputtering table 3 so that the surface on the side of the first metal oxide thin film becomes the deposition surface, and is rotated at a predetermined rotation speed. The predetermined rotation speed of the sputtering table 3 may be usually 1 to 1000 rpm, and preferably 2 to 50 rpm. The rotation speed may be constant during deposition of the metal thin film, or may be changed as desired.

[0075] Next, the inside of the sputtering chamber 5 is evacuated from the exhaust port 6 by an exhaust device (not shown) to make the pressure in the sputtering chamber 5 at the time of film formation equal to or lower than a predetermined pressure a″. The predetermined pressure a″ is usually 10 -5 ~10 -2 Pa, preferably 10 -4 ~5×10 -3 It may be on the order of Pa.

[0076] Next, sputtering gas is introduced into sputtering chamber 5 from sputtering gas inlet 7 so that the pressure inside sputtering chamber 5 becomes a predetermined pressure b" during film formation. The amount of sputtering gas introduced may be fixed, and the opening of exhaust port 6 may be feedback controlled to keep the sputtering pressure constant. The sputtering gas is not particularly limited as long as it is a gas that can be used for sputtering, and may be any known sputtering gas. The sputtering gas may be preferably a noble gas such as argon or krypton.

[0077] The predetermined pressure b'' (sputtering pressure) in the sputtering chamber 5 during the above-mentioned film formation may be usually 0.05 to 5 Pa, and preferably 0.1 to 1 Pa, from the viewpoint of stabilizing the discharge and enabling continuous film formation.

[0078] Next, a predetermined power is applied to the metal target to cause discharge, and when the discharge state becomes stable, the shutter 8 is opened to sputter the metal target, and the metal thin film is directly formed on the surface of the first metal oxide thin film of the intermediate laminate b. In addition, by keeping the shutter 8 closed until the discharge state becomes stable, it is possible to prevent the adhesion of the contaminants on the surface of the intermediate laminate b during pre-sputtering (an operation to remove contaminants such as dirt and water on the surface of the intermediate laminate b (by applying power to blow them away)). The power applied here may be DC power or AC power. Metals such as silver, copper, and aluminum have sufficiently high electrical conductivity, so the power applied may preferably be DC power.

[0079] The thickness of the metal thin film can be adjusted to a desired thickness by adjusting the power input to the metal target, the flow rate of the sputtering gas (predetermined pressure b″ (sputtering pressure) in the sputtering chamber 5 during film formation), and the film formation time. The relationship between the amount of input power, the flow rate of the sputtering gas, the film formation time, and the film thickness can be determined by conducting a preliminary experiment.

[0080] 3-4. Deposition of the second metal oxide thin film: Next, the second metal oxide thin film is formed directly on the surface of the metal thin film of an intermediate laminate c having, in that order, the first fluorine-doped cerium dioxide thin film, the first metal oxide thin film, and the metal thin film on one surface of a substrate 4.

[0081] The second metal oxide thin film can be formed by the same method as that explained in "3-2. Formation of first metal oxide thin film."

[0082] 3-5. Deposition of fluorine-doped cerium dioxide thin film b: Furthermore, an intermediate laminate d having the first fluorine-doped cerium dioxide thin film, the first metal oxide thin film, the metal thin film, and the second metal oxide thin film in this order on one surface of a substrate 4 is formed with the second fluorine-doped cerium dioxide thin film directly on the surface of the second metal oxide thin film, thereby obtaining a laminate of the present invention.

[0083] The second fluorine-doped cerium dioxide thin film can be formed in the same manner as described in "3-1. Formation of the first fluorine-doped cerium dioxide thin film".

[0084] At this time, it should be noted that, particularly when the surface of the substrate 4 on which the first fluorine-doped cerium dioxide thin film is directly formed is composed of an organic compound such as resin, the first fluorine-doped cerium dioxide thin film and the second fluorine-doped cerium dioxide thin film (formed on the surface of a metal oxide thin film, which is an inorganic substance) have different times until the sputtered film begins to grow, and therefore the film thicknesses often differ even under the same film formation conditions.

[0085] 4. Goods: The article of the present invention includes the multilayer thin film of the present invention or the laminate of the present invention. The article of the present invention has an infrared shielding function by including the multilayer thin film of the present invention or the laminate of the present invention. Examples of the article of the present invention include a member (film for glass) that is attached to window glass of buildings and windows of automobiles to impart heat insulation, window glass of buildings and windows of automobiles having heat insulation, etc. EXAMPLES

[0086] The present invention will be described below with reference to examples, but the present invention is not limited to these.

[0087] Measurement method (a) Solar radiation rejection rate: In accordance with the calculation of the 6.5 shading coefficient and solar heat gain coefficient of JIS A5759:2016, the solar transmittance and solar reflectance were measured with the multilayer thin film surface of the laminate facing the light source using a spectrophotometer "Solid Spec-3700 (product name)" made by Shimadzu Corporation. Next, in accordance with the measurement method of spectral reflectance and spectral transmittance in the wavelength range of room temperature thermal radiation and the calculation method of normal emissivity in Appendix JB of JIS R3106:2019, the glass surface of the laminate was set as the outdoor surface and the multilayer thin film surface was set as the indoor surface, and the normal emissivity of each was measured using an infrared spectrophotometer "Nicolet 380 (product name)" made by Thermo Fisher Scientific Co., Ltd. After that, the modified emissivity of each was calculated in accordance with Appendix A of JIS R3107:2019, the method of determining emissivity, and the method of determining modified emissivity of gas physical properties A.2. The proportion of solar heat absorbed by the test piece that is transferred indoors was calculated by substituting the obtained corrected emissivity of the indoor surface and the corrected emissivity of the outdoor surface into formula (5) of the above JIS standard. Next, the shading coefficient was calculated by substituting the obtained solar transmittance, solar reflectance, and the proportion of solar heat absorbed by the test piece that is transferred indoors into formula (4) of the above JIS standard. The solar heat gain coefficient was calculated by substituting the calculated shading coefficient into formula (6) of the above JIS standard. Next, the solar radiation rejection rate (unit: %) was calculated using the following formula (1). Solar radiation removal rate = 100 - solar heat gain rate × 100 (1)

[0088] (b) Thermal conductivity U: According to JIS R3106:2019, Appendix JB, Methods for measuring spectral reflectance and spectral transmittance in the wavelength range of room temperature thermal radiation and method for calculating normal emissivity, Thermo Fisher Scientific's Nicolet 380 (product name) infrared spectrophotometer was used to measure the normal emissivity of each of the laminated glass surface as the outdoor surface and the multilayer thin film surface as the indoor surface. Then, according to JIS R3107:2019, Appendix A, Method for determining emissivity, and A.2, Method for determining modified emissivity of gas physical properties, the modified emissivity of each was calculated. The modified emissivity of the outdoor surface and the modified emissivity of the indoor surface obtained were substituted into JIS A5759:2016, 6.6, Formula (7) for calculating the thermal transmittance, to obtain the thermal transmittance U (unit: W / m 2 ·K) was calculated.

[0089] (C) Visible light transmittance: In accordance with JIS A5759:2016, 6.4 Visible Light Transmittance Test, the visible light transmittance (unit: %) was measured using a spectrophotometer "Solid Spec-3700 (product name)" manufactured by Shimadzu Corporation, with the multilayer thin film surface of the laminate facing the light source.

[0090] (2) Haze: According to JIS K 7136:2000, the haze (unit: %) of the laminate was measured using a turbidity meter "NDH2000 (product name)" manufactured by Nippon Denshoku Industries Co., Ltd., with the multilayer thin film surface of the laminate facing the light source.

[0091] (e) Moisture and heat resistance: The laminate was treated for 720 hours in an environment of 60°C and 90% relative humidity, and then the following (f) appearance, Δhaze (the absolute value of the difference between the haze after moist heat treatment and the haze before moist heat treatment; each was measured using the above (d) haze), and thermal conductivity U after moist heat treatment (thermal conductivity U measured for the laminate after moist heat treatment using the above (b) thermal conductivity U method) were evaluated.

[0092] (F) Appearance: A photograph of the multilayer thin film surface of the laminate after the moist heat treatment was binarized using Open CV so that defective areas were colored white and normal areas were colored black, and the proportion of the white area was then calculated as the area of ​​appearance defects.

[0093] Raw materials used (A) Target: (A-1) A disk-shaped target with a diameter of 76.2 mm and a thickness of 3 mm obtained by sintering cerium dioxide from USTRON Corporation. Purity: 4N. (A-2) A disk-shaped target with a diameter of 76.2 mm and a thickness of 3 mm obtained by sintering aluminum trioxide manufactured by Toshima Manufacturing Co., Ltd. Purity: 4N. (A-3) A disk-shaped target with a diameter of 76.2 mm and a thickness of 3 mm obtained by melting and rolling copper manufactured by USTRON Corporation. Purity: 4N. (A-4) A disk-shaped target with a diameter of 76.2 mm and a thickness of 3 mm obtained by melting and rolling silver manufactured by USTRON Corporation. Purity: 4N.

[0094] (B) Gas: (B-1) Argon gas (grade 99.999% or higher purity). (B-2) Tetrafluoromethane (grade of 99.999% or higher purity).

[0095] (C) Base material: (C-1) Toray Industries, Inc.'s double-sided easy-adhesion treated biaxially oriented polyethylene terephthalate film "Lumirror U48 (product name)". Thickness: 125 μm.

[0096] Example 1 (1) Deposition of a first fluorine-doped cerium dioxide thin film: First, a batch-type sputtering apparatus, the conceptual diagram of which is shown in Figure 2, was used, and a first fluorine-doped cerium dioxide thin film was formed directly on one side of a film piece taken from (C-1) with a size of 40 mm in the machine direction and 40 mm in the lateral direction as a substrate, using (A-1), (B-1), and (B-2). First, (A-1) was attached to the target setting jig 2 of the sputtering apparatus. Next, the inside of the sputtering chamber 5 of the sputtering apparatus was heated to a pressure of 3.0 x 10 -3 The pressure in the sputtering chamber 5 was reduced to 0.4 Pa. Next, the gas flow (volume flow rate 19.80 sccm) of (B-1) and the gas flow (volume flow rate 0.20 sccm) of (B-2) were joined and mixed together and introduced as a sputtering gas from the sputtering gas inlet 7 into the sputtering chamber 5, and the aperture of the exhaust port 6 was feedback-controlled so that the pressure in the sputtering chamber 5 was 0.4 Pa. Next, the input power of 200 W (input power amount per unit area 4.4 W / cm2) was supplied to the above (A-1). 2 ) high frequency AC power was applied under the conditions of 0.1 to 1.5 V, sputtering was performed to form a sputtered film on one surface of the substrate, and an intermediate laminate a was obtained. The film formation time was 800 seconds, and the film formation conditions were such that the thickness of the sputtered film was 50 nm. The sputtered film was subjected to XPS analysis in the energy range of -10 to 1350 eV. From the spectrum obtained, the composition of the sputtered film was calculated to be carbon 29 at%, oxygen 20 at%, fluorine 38 at%, and cerium 13 at%. In other words, the proportion of fluorine atoms in the sputtered film (the first fluorine-doped cerium dioxide thin film) was 38 at%.

[0097] (2) Deposition of the first metal oxide thin film: Next, using a batch-type sputtering apparatus, the conceptual diagram of which is shown in Figure 2, the above (A-2) and (B-1) were used to directly form a first metal oxide thin film (aluminum trioxide thin film; indicated as "Al oxide" in the table) on the surface of the intermediate laminate a facing the first fluorine-doped cerium dioxide thin film. First, the above (A-2) was attached to the target setting jig 2 of the sputtering apparatus. Next, the inside of the sputtering chamber 5 of the sputtering apparatus was heated to a pressure of 3.0 x 10 -3The pressure in the sputtering chamber 5 was reduced to 0.4 Pa. Next, the gas flow (volume flow rate 20.00 sccm) of (B-1) was introduced as a sputtering gas from the sputtering gas inlet 7 into the sputtering chamber 5, and the aperture of the exhaust port 6 was feedback-controlled so that the pressure in the sputtering chamber 5 was 0.4 Pa. Next, the input power of 200 W (input power amount per unit area 4.4 W / cm2) was input to the (A-1). 2 ) high frequency AC power was applied to perform sputtering, forming a sputtered film (aluminum trioxide thin film) on the surface of the intermediate laminate a facing the first fluorine-doped cerium dioxide thin film, thereby obtaining an intermediate laminate b. The film formation time was 300 seconds, and the film formation conditions were such that the sputtered film had a thickness of 10 nm.

[0098] (3) Metal thin film deposition: Next, a batch-type sputtering apparatus, the conceptual diagram of which is shown in FIG. 2, was used to directly form a metal thin film (copper thin film) on the first metal oxide thin film (aluminum trioxide thin film) side of the intermediate laminate b, using the above (A-3) and (B-1). First, the above (A-3) was attached to the target setting jig 2 of the sputtering apparatus. Next, the inside of the sputtering chamber 5 of the sputtering apparatus was heated to a pressure of 3.0×10 -3 The pressure in the sputtering chamber 5 was reduced to 0.4 Pa. Next, the gas flow (volume flow rate 20 sccm) of (B-1) was introduced as a sputtering gas from the sputtering gas inlet 7 into the sputtering chamber 5, and the aperture of the exhaust port 6 was feedback-controlled so that the pressure in the sputtering chamber 5 was 0.4 Pa. Next, the input power of 100 W (input power amount per unit area 2.2 W / cm2) was input to the (A-3). 2 ) DC power was applied under the conditions of 1) to perform sputtering, and a sputtered film (thin copper film) was formed on the surface of the intermediate laminate b on the first metal oxide thin film (thin aluminum oxide film) side, thereby obtaining an intermediate laminate c. The film formation time was 30 seconds, and the film formation conditions were such that the thickness of the sputtered film was 10 nm.

[0099] (4) Deposition of the second metal oxide thin film: Next, in the same manner as in (2) forming the first metal oxide thin film above, a second metal oxide thin film (aluminum trioxide thin film) was formed on the metal thin film (copper thin film) side of the intermediate laminate c, thereby obtaining an intermediate laminate d.

[0100] (5) Deposition of the second fluorine-doped cerium dioxide thin film: Next, a second fluorine-doped cerium dioxide thin film was formed on the surface of the intermediate laminate d on the second metal oxide thin film (aluminum trioxide thin film) side in the same manner as in (1) above, except that the film formation time was changed to 300 seconds, to obtain a laminate. The film formation conditions were such that the thickness of the second fluorine-doped cerium dioxide thin film was 30 nm. The proportion of fluorine atoms was 38 at%.

[0101] The laminate thus obtained was subjected to the above tests (a) to (f). The results are shown in Table 1.

[0102] In this specification, the unit of volumetric flow rate "sccm" is the volume (unit: cc) of gas flowing per minute normalized under standard conditions (temperature 0° C., 1 atmospheric pressure).

[0103] Example 2 A laminate was obtained in the same manner as in Example 1, except that in the above (2) formation of the first metal oxide thin film, the above (A-1) was used instead of the above (A-2) and the film formation time was changed to 400 seconds, and in the above (4) formation of the second metal oxide thin film, the above (A-1) was used instead of the above (A-2) and the film formation time was changed to 150 seconds. The above tests (a) to (f) were carried out. The results are shown in Table 1.

[0104] Example 3 A laminate was obtained in the same manner as in Example 1, except that in the above (2) formation of the first metal oxide thin film, the above (A-1) was used instead of the above (A-2) and the film formation time was changed to 320 seconds, and in the above (4) formation of the second metal oxide thin film, the above (A-1) was used instead of the above (A-2) and the film formation time was changed to 150 seconds. The above tests (a) to (f) were carried out. The results are shown in Table 1.

[0105] Example 4 A laminate was obtained in the same manner as in Example 1, except that the above (2) formation of the first metal oxide thin film and the above (4) formation of the second metal oxide thin film were not performed, that is, the first fluorine-doped cerium dioxide thin film, the metal thin film, and the second fluorine-doped cerium dioxide thin film were formed in this order on the surface of the substrate, and the film formation time in the above (1) formation of the first fluorine-doped cerium dioxide thin film was changed to 1200 seconds. The above tests (a) to (f) were performed. The results are shown in Table 1.

[0106] Example 5 A laminate was obtained in the same manner as in Example 1, except that in the (3) formation of the metal thin film, (A-4) was used instead of (A-3) and the film formation time was changed to 15 seconds. The above tests (a) to (f) were carried out. The results are shown in Table 1.

[0107] Examples 6 and 7 A laminate was obtained in the same manner as in Example 1, except that in the above (1) formation of the first fluorine-doped cerium dioxide thin film, the volumetric flow rate of each of the sputtering gases was changed as shown in Table 1, and in the above (5) formation of the second fluorine-doped cerium dioxide thin film, the volumetric flow rate of each of the sputtering gases was changed as shown in Table 1. The ratios of fluorine atoms in the first fluorine-doped cerium dioxide thin film and the second fluorine-doped cerium dioxide thin film were both 15 at % in Example 7 and 56 at % in Example 8. The above tests (a) to (f) were performed. The results are shown in Table 1.

[0108] [Table 1]

[0109] It was confirmed that the multi-layer thin film of the present invention has an infrared shielding function and good resistance to moist heat. [Brief description of the drawings]

[0110] [Figure 1] This is a spectrum of an XPS analysis of a fluorine-doped cerium dioxide thin film in the energy range of -10 to 1350 eV. [Diagram 2] FIG. 2 is a conceptual diagram of a batch-type sputtering apparatus used in the examples. [Diagram 3] This is an example of an image obtained by binarizing a photograph of a multilayer thin film surface after the moist heat treatment in the moist heat resistance test (e) above, using the appearance method in the above test (f). [Explanation of symbols]

[0111] 1: Target 2: Target installation jig 3: Spatter table 4: Base material 5: Sputtering chamber 6: Exhaust port 7: Sputtering gas inlet 8: Shutter

Claims

1. A multilayer thin film comprising a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film stacked in this order.

2. the ratio of fluorine atoms in the first fluorine-doped cerium dioxide thin film is, in atomic ratio, 1 to 60 at %, with the total number of atoms in the first fluorine-doped cerium dioxide thin film being 100 at %, and a ratio of fluorine atoms in the second fluorine-doped cerium dioxide thin film is, in atomic ratio, 1 to 60 at %, with the total number of atoms in the second fluorine-doped cerium dioxide thin film being 100 at %; The multilayer thin film of claim 1.

3. 2. The multilayer thin film according to claim 1, wherein at least one thin film selected from the group consisting of the first metal oxide thin film and the second metal oxide thin film is a thin film of aluminum trioxide.

4. 2. The multilayer thin film according to claim 1, wherein at least one thin film selected from the group consisting of the first metal oxide thin film and the second metal oxide thin film is a cerium dioxide thin film.

5. The multi-layer film of claim 1 , wherein the metal film is a copper film.

6. The multi-layered film of claim 1 , wherein the metal film is an aluminum film.

7. The multilayer film of claim 1 , wherein the metal film is a silver film.

8. A laminate having the multilayer thin film according to any one of claims 1 to 7 on a part or all of the surfaces of a substrate.

9. An article comprising the multilayer thin film according to any one of claims 1 to 7.

10. A method for producing a multilayer thin film comprising a first fluorine-doped cerium dioxide thin film, a first metal oxide thin film, a metal thin film, a second metal oxide thin film, and a second fluorine-doped cerium dioxide thin film stacked in this order, comprising: The step of forming at least one thin film selected from the group consisting of the first fluorine-doped cerium dioxide thin film and the second fluorine-doped cerium dioxide thin film, Using a sputtering device, a cerium dioxide target and an organic fluorine compound gas are used. (1) a sub-step of mounting the cerium dioxide target on a target mounting jig of the sputtering apparatus; (2) a sub-step of reducing the pressure in the sputtering chamber of the sputtering apparatus to a predetermined pressure a; (3) a sub-step of introducing a mixed gas of a sputtering gas and the organic fluorine compound gas into a sputtering chamber of the sputtering apparatus so that the pressure in the sputtering chamber becomes a predetermined pressure b; and (4) a sub-step of applying power to the cerium dioxide target and sputtering the cerium dioxide target to form a fluorine-doped cerium dioxide thin film; wherein the mixing ratio of the sputtering gas to the organic fluorine compound gas (volume of the sputtering gas / volume of the organic compound gas) is 95 / 5 to 99.99 / 0.01; forming the fluorine-doped cerium dioxide thin film; A method for producing the multilayer thin film.

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