film

Abstract

Provided is a film comprising a fluorine resin, a chromatic color pigment, and a black pigment, wherein visible light transmittance is 5-60%, and haze is at most 30%.

Description

[Technical Field]

[0001] The present invention relates to a film. [Background technology]

[0002] Fluororesin films have excellent weather resistance, stain resistance, etc., and are therefore used as membrane materials (roofing materials, exterior wall materials, etc.) in membrane structures such as membrane structure facilities (sports facilities (swimming pools, gymnasiums, tennis courts, soccer fields, athletics stadiums, etc.), warehouses, assembly halls, exhibition halls, horticultural facilities (horticultural greenhouses, agricultural greenhouses, etc.)) (see, for example, Patent Document 1). Furthermore, in sports facilities, etc., colored fluororesin films colored white or blue are also used (see, for example, Patent Document 2).

[0003] When membrane materials using fluororesin films were first adopted for membrane structure applications, their major features were that they were lighter than glass, allowing for lightweight buildings, including aggregates, and that curved shapes were possible. In addition, membrane materials using colored film have the advantage of being able to determine the overall impression of the building, being able to provide a fantastic light at night with lighting devices (LED lighting, etc.) placed inside the membrane, and because the haze of colored film is usually 50% or more, the details of the lighting devices cannot be clearly seen from outside the building.

[0004] There are two methods for installing membrane materials: the cushion method and the tension method. In the cushion method, multiple sheets of membrane structure film are fixed to the aggregate to form a multi-layer membrane, with air supplied between them. In the tension method, a single sheet of membrane structure film is fixed to the aggregate. In recent years, the use of tension systems has been increasing due to their low installation costs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3623008 [Patent Document 2] Patent No. 5365195 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional membrane materials, especially those using the tension method, have the problem that they appear less substantial than glass that is about 10 mm thick. Although Patent Documents 1 and 2 discuss improving the weather resistance of fluororesin films, they do not discuss at all how to impart a sense of solidity to the fluororesin films. An object of the present invention is to provide a film having a solid, glass-like appearance. [Means for solving the problem]

[0007] The present invention provides a film having the following constitutions [1] to

[15] . [1] A composition containing a fluororesin, a chromatic pigment, and a black pigment, Visible light transmittance is 5 to 60%. A film having a haze of 30% or less. [2] The film according to [1] above, which has a fluororesin layer containing the fluororesin, the chromatic pigment, and the black pigment. [3] The film according to [2], wherein the black pigment comprises at least one selected from the group consisting of carbon black, aluminum interference pigment, iron oxide, titanium black, cobalt-iron-chromium composite oxide, copper-chromium-manganese composite oxide, iron-chromium composite oxide, and manganese-bismuth composite oxide. [4] The content of the black pigment per unit area of ​​the fluororesin layer is 0.003 to 0.150 g / m 2 The film according to [2] or [3] above. [5] The film according to [1] above, which has a fluororesin layer containing the fluororesin and the chromatic pigment, and a layer containing the black pigment. [6] The film according to [5], wherein the thickness of the layer containing the black pigment is 0.5 to 50 nm. [7] The film according to [5] or [6] above, wherein the layer containing the black pigment is a layer formed by a dry process. [8] The film according to any one of [5] to [7] above, wherein the black pigment contains at least one selected from the group consisting of metals and alloys. [9] The film according to any one of [5] to [8], wherein the black pigment comprises at least one selected from the group consisting of chromium, chromium alloys, nickel, nickel alloys, titanium, titanium alloys, zinc, zinc alloys, indium, and indium alloys.

[10] The film according to any one of [5] to [9] above, further comprising a protective layer on the layer containing the black pigment.

[11] The film according to

[10] , wherein the protective layer is a layer formed from a fluororesin having a reactive functional group, or a layer formed from at least one inorganic material selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides.

[12] The content of the chromatic pigment per unit area of ​​the fluororesin layer is 0.030 to 0.80 g / m 2 The film according to any one of [2] to

[11] above,

[13] The film according to any one of [1] to

[12] above, wherein the chromatic pigment has a blue or green color tone.

[14] The film of any of the above [1] to

[13] , wherein the fluororesin comprises at least one selected from the group consisting of vinyl fluoride polymer, vinylidene fluoride polymer, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-vinylidene fluoride-propylene copolymer, ethylene-tetrafluoroethylene copolymer, hexafluoropropylene-tetrafluoroethylene copolymer, ethylene-hexafluoropropylene-tetrafluoroethylene copolymer, perfluoro(alkyl vinyl ether)-tetrafluoroethylene copolymer, chlorotrifluoroethylene polymer, and ethylene-chlorotrifluoroethylene copolymer.

[15] The film according to any one of [1] to

[14] above, which is a film for a membrane structure. [Effects of the Invention]

[0008] The film of the present invention has a solid, glass-like appearance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a film according to a first embodiment. [Figure 2] FIG. 4 is a schematic cross-sectional view showing a film according to a second embodiment. [Figure 3] FIG. 10 is a schematic cross-sectional view showing a modified example of the film according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this disclosure, the following terms have the following meanings: The term "film" encompasses a monolayer film and a laminate film in which multiple layers are laminated. "Achromatic colors" are colors that contain only the dimension of lightness (colors that have no color at all), such as white, gray, and black. "Chromatic colors" are all colors other than achromatic colors (colors that have color regardless of their intensity). A "unit based on a monomer" of a polymer refers to a constituent portion of the polymer that is formed by polymerization of a monomer and is derived from the monomer. The unit may be a unit formed directly by a polymerization reaction, or may be a unit in which a portion of the structure of the unit is converted to a different structure by chemically converting the polymer obtained by the polymerization reaction. In the present disclosure, a "unit based on a monomer" is also referred to as a "monomer unit." The "visible light transmittance" is measured in accordance with DIN EN 410:1998. Details are as described in the examples below. "Haze" is measured in accordance with JIS K7136:2000, as described in detail in the Examples below. The symbol "to" indicating a numerical range means that the numerical values ​​before and after it are included as the upper and lower limits. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, the term "layer" includes cases where the layer is formed over the entire area when the area in which the layer exists is observed, as well as cases where the layer is formed over only a portion of the area. 1 to 3 are shown for the sake of convenience and include different dimensional ratios. In Figs. 1 to 3, each component is shown as a rectangle for the sake of convenience, but this does not represent the shape of each component.

[0011] The film of the present disclosure includes a fluororesin, a chromatic pigment, and a black pigment, The visible light transmittance is 5 to 60%, and the haze is 30% or less. The visible light transmittance of the film is preferably 10 to 40%. The haze of the film is preferably 20% or less. The lower the haze, the better, and there is no particular lower limit, but it is, for example, 2%.

[0012] When the film's visible light transmittance is 5% or more and its haze is 30% or less, the film transmits light, with most of that light being direct light. Furthermore, when the film contains chromatic pigments and black pigments to the extent that the visible light transmittance is 60% or less, the light that passes through the film becomes low-saturation light. This gives the film a sense of depth and solidity similar to that of glass about 10 mm thick, even when the film is thin. Furthermore, if the visible light transmittance of the film is 5% or more, when the film is used as a membrane structure film, problems such as the indoor darkness during the daytime being the same as when a metal roof or concrete wall with a visible light transmittance of 0% is suppressed, and the advantages of membrane structure films using fluororesin are more easily realized. If the visible light transmittance is 60% or less or the haze is 30% or less, a heavy feel like glass is more easily achieved.

[0013] The film of the present disclosure will be described below by showing embodiments with reference to the accompanying drawings, although the film of the present invention is not limited to the following embodiments.

[0014] [First embodiment] FIG. 1 is a schematic cross-sectional view of a film 1 according to the first embodiment. The film 1 has a fluororesin layer 10 containing a fluororesin 3, a chromatic pigment 5, and a black pigment 7. The fluororesin layer 10 may be made of a composition containing the fluororesin 3, the chromatic pigment 5, and the black pigment 7 (hereinafter also referred to as "composition A"). The visible light transmittance of the film 1 is 5 to 60%, and the haze is 30% or less. The preferred values ​​of the visible light transmittance and haze are as described above.

[0015] The thickness of the film 1 is preferably 100 μm or more, particularly preferably 200 μm or more, from the viewpoint of excellent strength, and is preferably 1,000 μm or less, particularly preferably 500 μm or less, from the viewpoint of ease of handling as a film for membrane structure.

[0016] The fluororesin layer 10 or composition A contains a fluororesin 3, a chromatic pigment 5, and a black pigment 7. The chromatic pigment 5 and the black pigment 7 are dispersed in the fluororesin 3. In the fluororesin layer 10 or composition A, a portion of the fluororesin 3 may be substituted with another thermoplastic resin. The fluororesin layer 10 or composition A may further contain other components as needed, as long as the effects of the present invention are not impaired.

[0017] <Fluoropolymer> The fluororesin 3 is not particularly limited as long as it is a thermoplastic resin containing fluorine atoms in the molecular structure of the resin, and various known fluororesins can be used. The ratio of fluorine atoms to the total mass of the fluororesin 3 (hereinafter also referred to as "fluorine atom content") is preferably 45 mass% or more, more preferably 50 mass% or more, and particularly preferably 55 mass% or more. When the fluorine atom content is equal to or more than the above-mentioned lower limit, the film has even better weather resistance, stain resistance, chemical resistance, and non-stick properties, and is particularly excellent in non-stick properties and stain resistance.

[0018] The fluororesin 3 preferably has a stress of 10 MPa or more for 10% elongation. The stress value for 10% elongation is determined for fluororesin films by the method specified in JIS K7127:1999 (Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets). Using a No. 5 dumbbell test piece, the stress is calculated by dividing the tension when stretched at a tensile speed of 200 mm / min by the original cross-sectional area of ​​the film. The stress at 10% elongation does not depend on the thickness of the film, but is largely dependent on the composition of the fluororesin. If the stress at 10% elongation is 10 MPa or more, the film will have excellent resistance to snow accumulation and wind pressure.

[0019] The fluororesin 3 is preferably a fluoroolefin polymer. The fluoroolefin polymer may be a homopolymer or copolymer of fluoroolefin. Examples of the copolymer include a copolymer of two or more types of fluoroolefin, and a copolymer of one or more types of fluoroolefin and one or more types of other monomer copolymerizable with fluoroolefin. The other monomer is preferably an olefin or perfluoro(alkyl vinyl ether). The fluoroolefin and the olefin each preferably have 2 or 3 carbon atoms. The perfluoro(alkyl vinyl ether) preferably has 3 to 6 carbon atoms. One type of other monomer may be used alone, or two or more types may be used in combination. The fluororesin 3 is preferably a fluororesin that does not have reactive functional groups such as hydroxyl groups and carboxy groups, in view of its excellent resistance to contamination and chemicals.

[0020] Preferable fluororesin 3 includes vinyl fluoride polymer (hereinafter also referred to as "PVF"), vinylidene fluoride polymer (hereinafter also referred to as "PVDF"), vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (hereinafter also referred to as "THV"), tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-vinylidene fluoride-propylene copolymer, ethylene-tetrafluoroethylene copolymer (hereinafter also referred to as "E Examples of the fluororesin include hexafluoropropylene-tetrafluoroethylene copolymer (hereinafter also referred to as "FEP"), ethylene-hexafluoropropylene-tetrafluoroethylene copolymer (hereinafter also referred to as "EFEP"), perfluoro(alkyl vinyl ether)-tetrafluoroethylene copolymer (hereinafter also referred to as "PFA"), chlorotrifluoroethylene polymer (hereinafter also referred to as "PCTFE"), and ethylene-chlorotrifluoroethylene copolymer (hereinafter also referred to as "ECTFE"). These fluororesins may be used alone or in combination of two or more. The total content of the above-listed fluororesins relative to the total amount of the fluororesins is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass. Among the above, PFA, FEP, ETFE, or ETCFE is preferred, and ETFE is particularly preferred from the standpoints of cost, mechanical strength, sputtering film formation properties, and the like.

[0021] ETFE is a copolymer having ethylene (hereinafter also referred to as "E") units and tetrafluoroethylene (hereinafter also referred to as "TFE") units. ETFE may further contain other monomer units in addition to E and TFE, as necessary.

[0022] The molar ratio of E units / TFE units in ETFE is preferably 40 / 60 to 70 / 30, more preferably 40 / 60 to 60 / 40. In 100 mol % of all units constituting ETFE, the total content of E units and TFE units is preferably 90 mol % or more, more preferably 95 mol % or more, and may be 100 mol %.

[0023] The other monomers may be any monomers copolymerizable with E and TFE, and examples thereof include fluorine-containing ethylenes such as CF2=CFCl and CF2=CH2; fluorine-containing propylenes such as CF2=CFCF3 and CF2=CHCF3; fluorine-containing alkylethylenes having a fluoroalkyl group having 2 to 10 carbon atoms, such as CH2=CHC2F5, CH2=CHC4F9, CH2=CFC4F9 and CH2=CF(CF2)3H; and CF2=CFO(CF2CFXO). m R f (In the formula, R f represents a perfluoroalkyl group having 1 to 6 carbon atoms, X represents a fluorine atom or a trifluoromethyl group, and m represents an integer of 1 to 5.) and other perfluoro(alkyl vinyl ethers); and vinyl ethers having a group convertible to a carboxylic acid group or a sulfonic acid group, such as CF2=CFOCF2CF2CF2COOCH3 and CF2=CFOCF2CF(CF3)OCF2CF2SO2F.

[0024] When ETFE has other monomer units, the content of the other monomer units in 100 mol % of all units constituting ETFE is preferably 0.3 to 10 mol %, more preferably 1 to 5 mol %.

[0025] The melting point of the fluororesin 3 is preferably 220° C. or higher. In a membrane structure, the temperature of the film for a membrane structure may reach a maximum of about 80° C. If the melting point is 220° C. or higher, sufficient heat resistance can be obtained for use in a film for a membrane structure. The melting point of the fluororesin 3 is preferably not more than 280° C., particularly preferably not more than 270° C. If the melting point is not more than the upper limit, the haze of the fluororesin layer 10, and therefore the haze of the film 1, tends to be easily reduced to 30% or less. The haze of a film is determined by the crystallinity, which is determined by the composition of the fluororesin and the cooling rate during film molding, the thickness of the film, and the particle size and concentration of the pigments (chromatic pigments, black pigments) dispersed in the film. One approach from the fluororesin side to obtaining a film with low haze is to use a resin with low crystallinity, melt it, and then rapidly cool it. Resins with low crystallinity are highly transparent, but generally tend to have a low melting point. The melting point is the temperature corresponding to the maximum value of the melting peak of the resin as measured by differential scanning calorimetry (DSC).

[0026] The content of fluororesin 3 is preferably 50% by mass or more, and more preferably 70% by mass or more, relative to the total mass of fluororesin layer 10 or the total mass of composition A. The upper limit of the content of fluororesin 3 relative to the total mass of fluororesin layer 10 or the total mass of composition A is, for example, 99.9998% by mass.

[0027] <Chromatic pigments> As the chromatic pigment 5, various pigments having a color tone other than achromatic colors can be used, and can be appropriately selected from, for example, organic pigments, inorganic pigments, glitter pigments (aluminum, stainless steel, pearl mica, etc.), etc. Infrared absorbing pigments, near-infrared reflective pigments, etc. can also be used as the chromatic pigment 5, as long as they have absorption in the visible light range and a color tone other than achromatic colors.

[0028] Specific examples of inorganic and organic pigments include aluminum-cobalt composite oxide (blue), tin-zinc-titanium composite oxide (orange), iron oxide (red), cobalt-nickel-zinc-titanium composite oxide (green), cobalt-magnesium-titanium composite oxide (green), bismuth vanadate composite oxide (yellow), nickel-antimony-chromium composite oxide (yellow), titanium-antimony-nickel composite oxide (yellow), zinc-iron composite oxide (brown), cobalt-nickel-silicon composite oxide (purple), cobalt-lithium-phosphorus composite oxide (purple), manganese oxide (purple), copper-iron-manganese composite oxide (deep purple), titanium nitride (deep blue), copper phthalocyanine (blue, green), cobalt phthalocyanine (blue), and quinacridone (red, purple). Specific examples of chromatic infrared absorbing pigments and near-infrared reflecting pigments that absorb light in the visible light region include boron compounds (green) such as lanthanum hexaboride, tungsten compounds (blue) such as cesium tungstate, indium tin oxide (light blue), and antimony tin oxide (blue). As the chromatic pigment 5, organic pigments such as copper phthalocyanine and quinacridone are preferred, since they are relatively unlikely to increase haze when the content is increased.

[0029] The chromatic pigment 5 is preferably one having a blue or green color tone, such as aluminum-cobalt composite oxide (blue), cobalt-nickel-zinc-titanium composite oxide (green), cobalt-magnesium-titanium composite oxide (green), copper phthalocyanine (blue, green), titanium nitride (deep blue), cobalt phthalocyanine (blue), etc. If the chromatic pigment 5 is blue or green, the color tone of the film 1 can be made reminiscent of the sky, sea, or forest. The chromatic pigment 5 may be used alone or in combination of two or more kinds.

[0030] The content of the chromatic pigment 5 varies depending on the thickness of the fluororesin layer 10, but is preferably 0.0001 to 0.2 mass%, more preferably 0.005 to 0.1 mass%, and particularly preferably 0.01 to 0.07 mass%, relative to the total mass of the fluororesin layer 10 or the total mass of composition A. If the content of the chromatic pigment 5 is within the above range, when the fluororesin layer 10 has a preferred thickness described below, the content of the chromatic pigment 5 per unit area of ​​the fluororesin layer 10 is likely to fall within a preferred range described below.

[0031] <Black pigment> The black pigment 7 reduces the saturation (darkens) of light transmitted through the film, enhancing the sense of depth. Examples of black pigments 7 include carbon black, interference aluminum pigments, iron oxide, titanium black, cobalt-iron-chromium composite oxides, copper-chromium-manganese composite oxides, iron-chromium composite oxides, and manganese-bismuth composite oxides. Black pigments 7 may be used singly or in combination of two or more. Among these, carbon black is preferred because it has a smaller particle size than other black pigments and can reduce visible light transmittance without significantly increasing haze. Carbon black generally has an average particle size of about 3 to 500 nm, and examples thereof include acetylene black, furnace black, channel black, lamp black, etc. Among these, acetylene black is preferred because it has a relatively small surface area and is highly dispersible in the fluororesin 3. Examples of acetylene black include Denka Black (registered trademark) manufactured by Denka Company Ltd. and Ace Black manufactured by Soltex. The average particle size is measured by a laser light scattering method.

[0032] The content of black pigment 7 is preferably 0.0001 to 0.04 mass%, and particularly preferably 0.01 to 0.03 mass%, relative to the total mass of fluororesin layer 10 or the total mass of composition A. If the content of black pigment 7 is within the above range, when fluororesin layer 10 has a preferred thickness described below, the content of black pigment 7 per unit area of ​​fluororesin layer 10 is likely to fall within a preferred range described below.

[0033] <Other thermoplastic resins> Examples of other thermoplastic resins include acrylic resins, polyester resins, polyurethane resins, nylon resins, polyethylene resins, polyimide resins, polyamide resins, polyvinyl chloride resins, and polycarbonate resins. These other thermoplastic resins may be used alone or in combination of two or more.

[0034] The content of the other thermoplastic resin is preferably 30% by mass or less, more preferably 10% by mass or less, and may be 0% by mass, relative to 100% by mass of the total of the fluororesin 3 and the other thermoplastic resin.

[0035] <Other ingredients> The fluororesin layer 10 or composition A may contain an antioxidant, metal soap, or hydrophobizing agent to disperse the chromatic pigment 5 or black pigment 7 well in the fluororesin 3. The use of an antioxidant or metal soap can prevent discoloration during compounding. The use of a hydrophobizing agent can suppress aggregation of the pigment in the film and also prevent discoloration during compounding. The antioxidant or metal soap may be used in combination with the hydrophobizing agent.

[0036] As the antioxidant, known antioxidants can be used, and examples thereof include phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, etc. Phosphite-based phosphorus-based antioxidants are particularly preferred because they are highly effective in preventing coloration during compounding when an organic pigment is used. Examples of the metal soap include zinc stearate and lithium stearate. These antioxidants and metal soaps may be used alone or in combination of two or more.

[0037] The total content of the antioxidant and the metal soap is, for example, about 0.2 to 10 parts by mass relative to 100 parts by mass of the total of the chromatic pigment 5 and the black pigment 7.

[0038] Examples of the hydrophobizing agent include a silane coupling agent having an alkyl group and a silicone compound. Examples of the alkyl group contained in the silane coupling agent include alkyl groups having 1 to 12 carbon atoms. Examples of the silane coupling agent include trialkoxysilanes such as isobutyltrimethoxysilane, hexyltrimethoxysilane, and (3,3,3-trifluoropropyl)trimethoxysilane; silazanes such as hexamethyldisilazane; and chlorosilanes such as dimethyldichlorosilane. Of these, isobutyltrimethoxysilane is preferred as the silane coupling agent.

[0039] The silicone compound is an organopolysiloxane having an organic group, preferably an alkyl group having 1 to 4 carbon atoms or a phenyl group. As the silicone compound, those generally called silicone oils can be used.As silicone oils, for example, straight silicone oils such as dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, alkylaralkyl-modified silicone oil, fluorinated alkyl-modified silicone oil, etc. can be mentioned.Among these, dimethyl silicone oil is preferred from the viewpoint of cost, and phenylmethyl silicone oil is preferred from the viewpoint of heat resistance. The kinematic viscosity of silicone oil at 25°C is 1,500mm 2 / sec or less. 2 If the time is less than 1 / second, the pigments are likely to adhere thinly and uniformly to the surfaces of the chromatic pigments and black pigments, and the dispersibility of the chromatic pigments 5 and black pigments 7 in the fluororesin 3 becomes better. Commercially available silicone compounds can be used. For example, dimethyl silicone oils include SH200 (product name) manufactured by DuPont Toray Specialty Materials Co., Ltd., KF96 (product name) manufactured by Shin-Etsu Chemical Co., Ltd., and TSF451 (product name) manufactured by Momentive Performance Materials. Phenylmethyl silicone oils include SH510 (product name), SH550 (product name), and SH710 (product name) manufactured by Dow Corning Toray Silicone Co., Ltd., and KF54 (product name) manufactured by Shin-Etsu Chemical Co., Ltd. These silicone compounds may have various molecular weights (viscosities).

[0040] The content of the hydrophobizing agent is, for example, about 1.5 to 10 parts by mass with respect to 100 parts by mass of the total of the chromatic pigment 5 and the black pigment 7.

[0041] (Fluororesin layer) In one embodiment, the fluororesin layer 10 is made of composition A. The content of the chromatic pigment 5 per unit area of ​​the fluororesin layer 10 is 0.030 to 0.80 g / m 2is preferable, and 0.050 to 0.50 g / m 2 is particularly preferable. When the content of the chromatic pigment 5 is equal to or greater than the lower limit, the color tone of the film 1 becomes sufficiently deep, and a profound feeling is easily achieved. When the content of the chromatic pigment 5 is equal to or less than the upper limit, the haze is low, and a profound feeling is easily achieved.

[0042] The content of the black pigment 7 per unit area of ​​the fluororesin layer 10 is 0.003 to 0.150 g / m 2 is preferable, and 0.005 to 0.150 g / m 2 More preferably, 0.010 to 0.120 g / m 2 is more preferably 0.040 to 0.120 g / m 2 is particularly preferable. When the content of black pigment 7 is equal to or greater than the lower limit, a sufficiently dark color is obtained, and a profound feeling is easily obtained. When the content of black pigment 7 is equal to or less than the upper limit, the haze is low, a profound feeling is easily obtained, and the color tone of the film becomes chromatic, resulting in excellent design properties.

[0043] The preferred thickness of the fluororesin layer 10 is the same as the preferred thickness of the film 1 .

[0044] (Film manufacturing method) The film 1 can be produced, for example, by kneading a fluororesin 3, a chromatic pigment 5, a black pigment 7, and, if necessary, other thermoplastic resins and other components to prepare a composition A, and then molding the obtained composition A into a film by a known molding method.

[0045] (Action and effect) The film 1 described above has a fluororesin layer 10 containing either a fluororesin 3, a chromatic pigment 5, and a black pigment 7, or a fluororesin 3, a chromatic pigment 5, and a black pigment 7, and has a visible light transmittance of 5 to 60% and a haze of 30% or less, giving it a heavy, glass-like appearance. For example, even if the thickness of the film 1 is less than 1 mm, it feels as thick and heavy as glass about 10 mm thick. The film 1 contains the fluororesin 3 and therefore has good weather resistance.

[0046] Conventionally, fluororesin films used in membrane structure films have tended to have lower visible light transmittance, higher haze, and whitish appearance as the film becomes thicker, while conversely, have higher visible light transmittance, lower haze, and more transparent appearance as the film becomes thinner. On the other hand, colored glass for building materials generally has a thickness of 2 to 20 mm, and has low visible light transmittance, but low haze and high transparency. It is also heavy. Film 1 has optical properties that are closer to those of building glass than conventional fluororesin films, such as low visible light transmittance and low haze, and is therefore thought to make the film appear thick and heavy regardless of the actual thickness or mass of the material.

[0047] Second Embodiment 2 is a schematic cross-sectional view of a film 2 according to the second embodiment. In the following, components corresponding to those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted. The film 2 has a fluororesin layer 21 containing a fluororesin 3 and a chromatic pigment 5, and a layer 23 containing a black pigment (hereinafter also referred to as a "black pigment layer") provided on the fluororesin layer 21. The fluororesin layer 21 may be composed of a composition containing the fluororesin 3 and the chromatic pigment 5 (hereinafter also referred to as "composition B"). The black pigment layer may consist of a black pigment or may contain components other than the black pigment. The content of the black pigment relative to the total amount of the black pigment layer is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass (i.e., the black pigment layer consists of the black pigment). The visible light transmittance of the film 2 is 5 to 60%, and the haze is 30% or less. The preferred values ​​of the visible light transmittance and haze are as described above. The preferred thickness of film 2 is similar to the preferred thickness of film 1.

[0048] The fluororesin layer 21 or composition B contains a fluororesin 3 and a chromatic color pigment 5. The chromatic color pigment 5 is dispersed in the fluororesin 3. The fluororesin layer 21 or composition B may further contain a black pigment 7. In the fluororesin layer 21 or composition B, a part of the fluororesin 3 may be substituted with another thermoplastic resin. Examples of the other thermoplastic resin include the same ones as those mentioned above. The fluororesin layer 21 or composition B may further contain other components as needed, provided that the effects of the present invention are not impaired. Examples of other components include those similar to those described above.

[0049] In the fluororesin layer 21 or composition B, the preferred contents of the fluororesin 3, chromatic color pigment 5, other thermoplastic resin, and other components are the same as the preferred contents of each component in composition A. The content of the black pigment 7 is preferably 0.03 mass % or less, particularly preferably 0.00 mass %, relative to the total mass of the fluororesin layer 21 or the total mass of the composition B.

[0050] (Fluororesin layer) In one embodiment, the fluororesin layer 21 is made of composition B. The content of the chromatic pigment 5 per unit area of ​​the fluororesin layer 21 is 0.030 to 0.80 g / m 2 is preferable, and 0.050 to 0.50 g / m 2 is particularly preferable. When the content of the chromatic pigment 5 is equal to or greater than the lower limit, the color tone of the film 2 becomes sufficiently deep, and a profound feeling is easily achieved. When the content of the chromatic pigment 5 is equal to or less than the upper limit, the haze is low, and a profound feeling is easily achieved.

[0051] The thickness of the fluororesin layer 21 is preferably 100 μm or more, and particularly preferably 200 μm or more, in terms of excellent strength. The thickness of the fluororesin layer 21 is preferably 1,000 μm or less, and particularly preferably 500 μm or less, in terms of ease of handling of the film 2 as a film for membrane structure.

[0052] In order to improve the adhesion between the fluororesin layer 21 and the black pigment layer 23, the surface of the fluororesin layer 21 on the black pigment layer 23 side may be subjected to a surface treatment. The surface treatment is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected from known surface treatment methods. Examples include plasma treatment and corona discharge treatment. Of these, plasma treatment is preferred because it can uniformly treat the entire treatment surface of the fluororesin layer 21, imposes a small load on the surface of the fluororesin layer 21, and has little effect on the long-term stability of adhesion.

[0053] (black pigment layer) The black pigment layer 23, like the black pigment 7 dispersed in the fluororesin layer 10 in the first embodiment, reduces the saturation (darkens) of light transmitted through the film, thereby enhancing the sense of depth. The black pigment constituting the black pigment layer 23 preferably contains at least one selected from the group consisting of metals and alloys, and more preferably contains at least one selected from the group consisting of chromium, chromium alloys, nickel, nickel alloys, titanium, titanium alloys, zinc, zinc alloys, indium, and indium alloys. The black pigment may consist of at least one selected from the group consisting of metals and alloys, or may contain other black pigments. The total content of at least one selected from the group consisting of metals and alloys relative to the total amount of the black pigment is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass. Metals and alloys reduce transmittance through absorption and reflection, darkening the film. Their wavelength absorption characteristics are nearly identical to those of carbon black and cobalt-iron-chromium composite oxides, which are representative black pigments. Therefore, they can be considered black pigments. Furthermore, metals and alloys bond strongly to the surface of the fluororesin layer 21, providing excellent adhesion to the fluororesin layer 21.

[0054] Of the above metals or alloys that constitute the black pigment layer 23, chromium and chromium alloys are particularly preferred because of their excellent adhesive strength to the fluororesin layer 21. The chromium alloy is preferably at least one selected from the group consisting of tin-chromium alloy, titanium-chromium alloy, nickel-chromium alloy, zirconium-chromium alloy, niobium-chromium alloy, and tantalum-chromium alloy. The proportion of chromium atoms in 100% by mass of the chromium alloy is preferably 20% by mass or more, and particularly preferably 30% by mass or more, in consideration of adhesion to the fluororesin layer 21. There is no particular upper limit, and it can be appropriately selected taking into consideration the molding speed of the black pigment layer 23, etc.

[0055] The black pigment layer 23 may consist of a single layer, or may consist of multiple layers containing different types of black pigment (for example, a laminated film consisting of a chromium film and a chromium alloy film, or a laminated film each composed of a different chromium alloy, etc.).

[0056] The thickness of the black pigment layer 23 (total thickness when consisting of multiple layers) is preferably 0.5 to 50 nm. The lower limit is more preferably 1 nm, particularly preferably 3 nm. The upper limit is more preferably 25 nm, particularly preferably 10 nm. If the thickness of the black pigment layer 23 is equal to or greater than the lower limit, it is easy to ensure adhesion to the fluororesin layer 21 and to darken the light transmitted through the film. In particular, if the thickness is 3 nm or greater, visible light is clearly reflected, resulting in a film with reflective properties similar to those of architectural glass, giving the film a more substantial feel. If the thickness of the black pigment layer 23 is equal to or less than the upper limit, it is easy to ensure the flexibility of the film 2, adhesion to the fluororesin layer 21, and visible light transmittance.

[0057] The black pigment layer 23 is preferably a layer formed by a dry method. A layer formed by a dry method tends to have a more uniform thickness, higher adhesion to the fluororesin layer 21, and lower haze than a layer formed by a wet method. Dry methods include physical vapor deposition (hereinafter also referred to as "PVD method") and chemical vapor deposition (hereinafter also referred to as "CVD method").

[0058] Examples of the PVD method include vacuum deposition, sputtering, ion plating, etc. Any of these methods may be used. Among these, sputtering is preferred because it has excellent productivity, is widely used industrially, and can produce a very dense film with high adhesion to the fluororesin layer 21 with a uniform thickness. As the sputtering method, any of DC sputtering, RF sputtering, and AC sputtering can be used. DC sputtering and AC sputtering are preferred from the viewpoint of excellent productivity, such as the ability to efficiently form a film on a large-area substrate at a high film formation rate. Examples of the CVD method include plasma CVD, thermal CVD, catalytic CVD, etc. Any of these methods may be used. Among these, plasma CVD is preferred because it has excellent productivity, is widely used industrially, and can produce a very dense film with high adhesion to the fluororesin layer 21 with a uniform thickness.

[0059] The specific conditions for forming the black pigment layer 23 can be appropriately set depending on the method and material used. For example, a layer made of chromium can be obtained by forming a film by sputtering using a chromium target in an atmosphere of an inert gas such as argon. The specific sputtering conditions at this time may vary depending on the type of apparatus, target composition, and other conditions, so they may be selected appropriately. -4 After evacuating to a vacuum of 1000 Pa, argon was introduced into the chamber, and the sputtering gas pressure was set to 0.1 to 1.3 Pa and the power density to 0.5 to 5 W / cm. 2 It is preferable to do this with A layer made of a chromium alloy can be formed in the same manner as above, except that a chromium alloy target is used instead of the chromium target.

[0060] (Film manufacturing method) The film 2 can be produced, for example, by kneading the fluororesin 3, the chromatic pigment 5, and, if necessary, other thermoplastic resins and other components to prepare a composition B, molding the obtained composition B into a film by a known molding method, and then subjecting the molded film (fluororesin layer 21) to a surface treatment if necessary, followed by forming the black pigment layer 23.

[0061] (Action and effect) The film 2 described above has a fluororesin layer 21 containing a fluororesin 3 and a chromatic pigment 5, and a black pigment layer 23, and has a visible light transmittance of 5 to 60% and a haze of 30% or less, giving it a heavy, glass-like appearance. For example, even if the thickness of the film 2 is less than 1 mm, it feels as thick and heavy as glass about 10 mm thick. Furthermore, since the film 2 contains the fluororesin 3, it also has good weather resistance.

[0062] Other Embodiments Although the film of the present disclosure has been described above with reference to an embodiment, the present invention is not limited to the above embodiment. The configurations and combinations thereof in the above embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible within the scope of the present invention. For example, as shown in FIG. 3, a protective layer 25 may be provided on the black pigment layer 23 of the film 2 in the second embodiment.

[0063] The protective layer 25 protects the black pigment layer 23 . When the adhesion between the black pigment layer 23 and the fluororesin layer 21 is high, for example, when the black pigment layer 23 is made of a metal or an alloy, peeling is unlikely to occur even without the protective layer 25. For example, peeling does not occur in a Scotch tape peeling test after crosscutting in a grid pattern or after an accelerated weather resistance test. It is preferable to provide the protective layer 25 in order to prevent film thinning or scratches on the black pigment layer 23 due to physical abrasion, such as rubbing the surface of the black pigment layer 23 with an eraser. In membrane structure films and agricultural greenhouse films, in consideration of weather resistance, it is preferable to position the film 2 so that the fluororesin layer 21 is on the outer side (sun side) of the black pigment layer 23. In this case, even without the protective layer 25, the black pigment layer 23 does not come into contact with outdoor sand, pebbles, snow, ice, etc., so there is no need to consider thickness reduction of the black pigment layer 23 due to contact with these. However, during the processes of cutting the film 2, heat sealing the films 2 together, transporting, and installing the film 2 before installation, it is conceivable that the film 2 will be dragged on a workbench or the surface of the black pigment layer 23 will be rubbed with bare hands. To prevent scratches due to abrasion during this process, the protective layer 25 may be provided even when the fluororesin layer 21 is positioned on the outer side (sun side) of the black pigment layer 23. The film 2A having the protective layer 25 on the black pigment layer 23 is resistant to scratches due to abrasion during handling, and has excellent abrasion resistance.

[0064] The protective layer 25 is preferably a layer formed from a fluororesin having a reactive functional group, or a layer formed from at least one inorganic material selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides.

[0065] The protective layer 25 may be a layer formed by a dry method or a layer formed by a wet method, but is preferably a layer formed by a dry method. A layer formed by a dry method tends to have a more uniform thickness and better adhesion to the black pigment layer 23 than a layer formed by a wet method. The dry method may be the same as that described above. In the wet method, a coating liquid containing the components constituting the protective layer or their precursors and a liquid medium (water, organic solvent, etc.) is applied onto the black pigment layer 23, and then dried to form the protective layer. As the application method, a known wet coating method such as a gravure roll can be used.

[0066] As the protective layer formed by the dry method (hereinafter also referred to as "dry protective layer"), a layer formed from at least one inorganic material selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides is preferable. The total content ratio of at least one selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides with respect to the total amount of the dry protective layer is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 99% by mass or more, and particularly preferably 100% by mass. Examples of the inorganic oxide include oxides of at least one metal selected from the group consisting of aluminum, silicon, and magnesium, and silicon oxide (SiO x , 0 < x ≦ 2), and aluminum oxide (AlO x , 0 < x ≦ 1.5) are preferable. Examples of the inorganic nitride include silicon nitride (SiN x , 0 < x ≦ 1.3), and aluminum nitride (AlN x , 0 < x ≦ 1). Examples of the inorganic oxynitride include silicon oxynitride (SiO x N y , 0 < x < 1, 0 < y < 1).

[0067] The specific formation conditions of the dry protective layer can be appropriately set according to the method and material used. For example, a layer made of aluminum oxide can be obtained by film formation by a sputtering method in an oxygen-containing atmosphere using an aluminum target. At this time, by applying an intermittent negative DC voltage to the target, the generation of arcing during film formation can be effectively suppressed, the input power can be increased, and a larger film formation rate can be maintained for a long time. The specific sputtering conditions at this time vary depending on various conditions such as the type of apparatus and the target composition, so they can be appropriately selected. Generally, after evacuating to 8 × 10 -4 Pa, argon and oxygen are introduced into the container at a flow rate ratio of 0:100 to 90:10, and it is preferably carried out at a sputtering gas pressure of 0.1 to 1.3 Pa and a power density of 0.5 to 5 W / cm 2 .

[0068] The dry protective layer may be composed of a single layer or multiple layers made of different materials, for example, multiple layers made of different types of inorganic materials as main components.

[0069] The thickness of the dry protective layer (total thickness when it is composed of multiple layers) is preferably 10 nm or more from the viewpoint of abrasion resistance, and is preferably 100 nm or less, particularly preferably 50 nm or less, from the viewpoint of maintaining the flexibility and ensuring adhesion of the film 2.

[0070] Examples of protective layers formed by a wet method (hereinafter also referred to as "wet protective layers") include layers made of inorganic compounds (hereinafter also referred to as "wet inorganic protective layers") and layers made of organic compounds (hereinafter also referred to as "wet organic protective layers"). Examples of the wet inorganic protective layer include a silica layer, a silica-boehmite layer, and a boehmite layer. The thickness of the wet inorganic protective layer is, for example, 0.1 to 2 μm.

[0071] The wet-type organic protective layer is preferably a layer formed from a fluororesin having a reactive functional group. The content of the fluororesin having a reactive functional group relative to the total amount of the wet-type organic protective layer is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass. Examples of the reactive functional group include a hydroxyl group and a carboxyl group. In this layer, the fluororesin may be crosslinked by a reaction between the reactive functional groups or a reaction between the reactive functional group and a curing agent.

[0072] The fluororesin having a reactive functional group is preferably a copolymer of one or more fluoroolefins and one or more other monomers copolymerizable with the fluoroolefin. As the fluororesin having a reactive functional group, a fluororesin having a hydroxyl group or a carboxyl group is preferred, and a fluororesin having a hydroxyl group is particularly preferred. Commercially available examples of such fluororesins include the Lumiflon (registered trademark) series (LF200, LF100, LF710, etc.) (manufactured by AGC Inc.), the Zeffle (registered trademark) GK series (GK-500, GK-510, GK-550, GK-570, GK-580, etc.) (manufactured by Daikin Industries, Ltd.), the Fluonate (registered trademark) series (K-700, K-702, K-703, K-704, K-705, K-707, etc.) (manufactured by DIC Corporation), and the ETERFLON series (4101, 41011, 4102, 41021, 4261A, 4262A, 42631, 4102A, 41041, 41111, 4261A, etc.) (manufactured by Eternal Chemical Co., Ltd.).

[0073] The wet organic protective layer may contain other components, such as a curing catalyst, a non-fluorine-based resin, an anti-blocking agent, and known additives, as long as the effects of the present invention are not impaired. The thickness of the wet organic protective layer is, for example, 0.3 to 3 μm.

[0074] The wet organic protective layer can be formed, for example, by adding a solvent such as toluene, xylene, methyl isobutyl ketone, or methyl ethyl ketone (hereinafter also referred to as "MEK") to a fluororesin having a reactive functional group to adjust the viscosity to an appropriate level, adding a curing agent, an anti-blocking agent, and other components as necessary to prepare a coating liquid, applying the coating liquid onto the black pigment layer 23, and drying it. When a curing agent is used, the type and equivalent ratio of the curing agent are adjusted to optimize the flexibility of the cured film.

[0075] [Application] The film of the present disclosure has a heavy appearance and is therefore suitable as a film for membrane structures, particularly as a film for tension-type membrane structures. The film for membrane structures is used as a membrane material for constructing membrane structures. A membrane structure is a building in which at least a portion of the roof, exterior wall, etc. is constructed from a membrane material. Examples of membrane structures include sports facilities (swimming pools, gymnasiums, tennis courts, soccer fields, American football stadiums, etc.), warehouses, assembly halls, exhibition halls, horticultural facilities (horticultural greenhouses, agricultural greenhouses, etc.), shopping centers, parking lots, bicycle parking lots, zoos, and livestock barns.

[0076] The film of the present disclosure can be used not only for membrane structure films, but also for screens, sails for yachts, road signs, release films, labels, stickers, and the like. The screen can be installed as a single unit in any location (outdoors such as an outdoor theater, indoors, etc.), or can be used to form a membrane structure. Screens can be used for a variety of purposes, including, but not limited to, the following applications in buildings and other structures: · Displaying residential interiors, commercials, and educational images; · Displaying advertisements by projection from inside buildings; · Displaying information and advertisements at car dealerships; · Displaying advertisements, films, and exterior design changes in triangular or lattice-blocking windows in buildings, particularly at the top of windows; · Used as glass doors in supermarkets, retail stores, and public buildings for advertising, information notices, and events; · Displaying plant growth information as a structural material in greenhouses, etc.; · Used as glass walls with changeable wallpaper patterns; · Backboards in stadiums, studios, etc.; · Bathroom partitions in hotels, etc.; · Used as privacy screens that can switch between projecting and not projecting appropriate images and / or light. In particular, in conference rooms, hospitals, banks, restaurants, and public facilities, the non-projection mode allows for clear visibility, improving security during security operations when the privacy filter is not in use, as the non-projection mode allows for clear visibility. ·Displaying text, signs, images, and videos in airports, stations, hospitals, and schools. ·Displaying local and tourist information in religious facilities such as temples, shrines, Shinto shrines, and churches. ·Spatial design in commercial facilities. ·Projection mapping. ·Displaying text, signs, images, and videos in stadiums. ·Projecting information in kitchens and images for individuals. ·Whiteboards. For example, used in schools and meeting rooms as a component that can be written on and displayed. Also used in conjunction with a user interface. ·Used in insulating double-pane glass for refrigerator doors in supermarkets and convenience stores.

[0077] Screens can be used for tabletops, casings, etc. as follows: ·Restaurant tabletops ·Sushi restaurant counters ·Desks (desktops) and kitchen counters ·Tabletop partitions ·Showcases in the basement of department stores ·Showcases and changing rooms in boutiques ·Vending machines ·Partitions in pachinko parlors ·Front glass of pachinko machines. When playing pachinko, it is transparent so you can play normally. When the machine is empty and no one is sitting on it, the front glass can be used to advertise the store.

[0078] The following are examples of uses of screens in vehicles: In railway vehicles, it is used for: - Window glass behind the driver's seat (to prevent reflection of interior lighting when driving underground). - Information display on railway side window glass. - Hanging advertisements. - Partition area of ​​Shinkansen. - Window glass of linear motor cars. - Adding screen functionality to train windows. It is particularly preferable to use it after sunset as it improves visibility. In automobiles, etc., displays on the shade part of the windshield. Information displayed at the bottom of the windshield for automobiles. Information and image displays on interior partitions in taxis and limousines, etc. In-car advertising on buses (behind the driver). Automobile sun visors. TV and DVD image displays as interior partitions in minivans and sports utility vehicles (SUVs). Displays such as "Caution!" on the door glass when the side door is opened. Mounted on the rear glass for backlighting, high-mounted stop lamps (HMSL), rear information displays, and destination displays for buses, etc. Surrounding meters. Door glass screens. Other applications of the screen include anti-glare glass, anti-glare mirrors, traffic light cover glass (integration of various traffic light displays), etc.

[0079] The disclosure of Japanese Patent Application No. 2020-112390 is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are incorporated by reference into this specification to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. [Example]

[0080] Specific examples of the above-described embodiment will be described below as working examples, but the present invention is not limited to the following examples. Examples 2 to 8, 10, 11, and 13 to 19 are working examples, and Examples 1, 9, 12, and 20 are comparative examples. The measurement and evaluation methods used in the following examples are as follows.

[0081] [Evaluation method] (Optical properties) The haze was measured using a turbidity meter (product name "NDH-5000", manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136:2000. The visible light transmittance was measured using an ultraviolet-visible spectrophotometer (product name "UV-3600PC", manufactured by Shimadzu Corporation) in accordance with DIN EN 410:1998. The optical properties of the film with a black pigment layer and the film with both a black pigment layer and a protective layer were measured in the direction in which light was incident from the side opposite to the side on which these layers were formed (the ETFE side).

[0082] (film thickness) The thickness (μm) of the film was measured using a contact micrometer (product name "MDE-50MJ", manufactured by Mitutoyo Corporation).

[0083] (Thickness of black pigment layer and dry protective layer) The thicknesses (nm) of the black pigment layer and the dry protective layer were calculated using a spectroscopic ellipsometry device (product name "M-2000DI", manufactured by J.A. Woollam Japan Co., Ltd.) and optical fitting using WVASE32 (manufactured by J.A. Woollam Japan Co., Ltd.).

[0084] (Wet protective layer thickness) The thickness of the wet protective layer was calculated from the difference in mass per unit area before and after forming the wet protective layer and the specific gravity of the wet protective layer measured in advance.

[0085] (Deep feeling) Two rectangular aluminum frames measuring 15cm x 50cm were prepared. Double-sided adhesive tape was attached to both frames, and 1mm thick butyl rubber was fixed on top of that. Next, double-sided adhesive tape was attached to the butyl rubber on one of the frames, and a film was placed on top of that. The other frame was then placed on top of it so that the butyl rubber was in contact with the film side, and the four corners were tightened. In this way, a test specimen was prepared in which the film was sandwiched between the frames. The specimen was set up outdoors, and an observer visually inspected the specimen from a distance of 2 m. If the film on the specimen looked like glass about 10 mm thick, it was judged to have a "solid feel," and if it did not, it was judged to have a "lack of solid feel." If the film had a laminated structure (a film with a black pigment layer, or a film with both a black pigment layer and a protective layer), the specimen was set up so that the side closest to the observer was the fluororesin layer side, and the side furthest from the observer was the black pigment layer or the protective layer side. If the film had a single-layer structure (a film consisting only of a fluororesin layer), there was no distinction between the front and back of the specimen. Ten observers were counted, and the number of people who judged the appearance to be "dignified" was counted. When the number of people who judged the appearance to be "dignified" was seven or more, the score was "A" (passable), and when it was six or less, the score was "C" (unacceptable).

[0086] (Adhesion and abrasion test) Two tests, an adhesion test and an abrasion test, were conducted, and those that did not pass the adhesion test were given a C (fail), those that passed the adhesion test but did not pass the abrasion test were given a B (passable), and those that passed both tests were given an A (good). The adhesion test was conducted only on films with only a black pigment layer or both a black pigment layer and a protective layer. Films without these layers (films consisting of only a fluororesin layer) were judged to pass the test without conducting the adhesion test, since there was no layer to peel off.

[0087] <Adhesion test> The adhesion test was a cross-cut adhesion test using Cellotape (registered trademark), in which 100 1 mm squares were cut with a cutter on the black pigment layer alone or on the black pigment layer and protective layer of the film, and the adhesion test was carried out using Cellotape (registered trademark) (product name "CT-18", manufactured by Nichiban Co., Ltd.). If one or more of the 100 squares peeled off, the test was deemed to have failed, and if no peeling at all, the test was deemed to have passed.

[0088] <Wear test> The abrasion test was carried out using an eraser, with a load of 10 N applied to the eraser, which was rubbed back and forth three times on each side of the film. After that, the film was visually observed for any change in color and judged. Films that showed a lighter color were deemed to have failed, and films that showed no change in color were deemed to have passed.

[0089] (Weather resistance test) The film was placed in an accelerated weathering test device (Sunshine 300, manufactured by Suga Test Instruments Co., Ltd.) and exposed for 5,000 hours. The exposure conditions were a black panel temperature of 63°C. For all samples, the surface that was directly exposed to showers and light was the surface containing fluororesin. After exposure, the visible light transmittance was measured, and the rate of increase compared to the visible light transmittance before exposure was calculated. The closer the rate of increase in visible light transmittance is to 0%, the better the weather resistance. An increase in visible light transmittance of more than 5% can be considered to have a large change in visible light transmittance.

[0090] [Example 1] A blend was obtained by blending ETFE (product name "Fluon ETFE 55AXP", manufactured by AGC Inc., melting point 260°C) with copper phthalocyanine blue (product name "Chromofine Blue", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and phenylmethyl silicone oil (product name "KF54", manufactured by Shin-Etsu Chemical Co., Ltd.). The blending amounts of copper phthalocyanine blue and phenylmethyl silicone oil were set so that their respective concentrations in 100% by mass of the blend were 0.021% by mass and 0.001% by mass. Thereafter, the above blend was melt-kneaded using a twin-screw extruder (φ15 mm, L / D=45) manufactured by Technovel Industries Co., Ltd., set at 320° C., to obtain pellets. Next, a 250 mm wide film-forming T-die was attached to a 30 mm diameter single-screw extruder (equipped with a screw with an L / D of 22 and a compression ratio of 3.0) and heated to 320°C. The pellets were fed into the single-screw extruder, and the molten material extruded from the film-forming T-die was passed through a metal roll, the roll temperature of which was maintained at 150°C by a thermal coolant, using a constant-speed take-up device, to obtain an ETFE film (fluororesin layer) with a thickness of 250 μm. This ETFE film was designated as the film of Example 1. The obtained film exhibited a highly saturated blue color. The mass of copper phthalocyanine blue per unit area of ​​this film (fluororesin layer) was 0.092 g / m, since the specific gravity of ETFE was 1.75 and the thickness of the ETFE film was 250 μm. 2 The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the film are shown in Table 2. "φ" indicates the cylinder diameter. "L / D" indicates the value obtained by dividing the screw length L (m) by the screw diameter D (m). "Compression ratio" is a characteristic value of the screw shape calculated from the ratio of the groove depth of the screw material sharing section and the screw metering section.

[0091] [Example 2] The ETFE film with a thickness of 250 μm obtained in Example 1 was placed in a sputtering device (Canon Tokki Corporation), and 6.7 × 10 -4 After evacuating the chamber to approximately 100 Pa, Ar gas was introduced into the chamber at 50 sccm, and the pressure was adjusted to 0.3 Pa. Subsequently, plasma was generated by applying a DC voltage with a power of 200 W. Using chromium as the target, a thin chromium film (black pigment layer) with a thickness of 8 nm was formed on the ETFE film by opening and closing the shutter to control the film formation time. The resulting laminate was designated the film of Example 2. The resulting film exhibited a low-saturation bluish-black color. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0092] [Example 3] 12 g of a chlorotrifluoroethylene-based fluororesin varnish having hydroxyl groups (product name "LF200MEK", manufactured by AGC Inc., solvent: MEK, solid content: 60% by mass) and 0.8 g of an isocyanate curing agent (product name "Coronate 2096", manufactured by Tosoh Corporation, solid content: 90% by mass) were mixed, and 12 g of a 50 / 50 (mass ratio) toluene / MEK mixed solvent was added to obtain a coating liquid with a No. 3 Zahn cup viscosity of 20 seconds. This coating solution was applied using a gravure roll onto the thin chromium film of the laminate obtained in Example 2, and dried at 100°C for 20 seconds to form a wet protective layer with a dry thickness of 1 µm. The resulting laminate was used as the film of Example 3. The obtained film showed slightly red interference fringes on the wet protective layer side, but the color tone when viewed from the ETFE side did not change before or after the wet protective layer was formed. The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the film are shown in Table 2.

[0093] [Example 4] A laminate was produced in the same manner as in Example 2, except that the thickness of the chromium thin film was changed to 4 nm, and this laminate was used as the film of Example 4. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0094] [Example 5] A wet protective layer was formed in the same manner as in Example 3 on the thin chromium film of the laminate obtained in Example 4, and the resulting laminate was designated as the film of Example 5. Table 1 shows the composition of the film's materials, and Table 2 shows the optical properties and evaluation results of the film.

[0095] [Example 6] Except for changing the target from chromium to indium, an 8 nm-thick indium thin film (black pigment layer) was formed on an ETFE film in the same manner as in Example 2. The obtained laminate was designated as the film of Example 6.

[0096] [Examples 7-11] A blend was obtained by blending ETFE (product name "Fluon ETFE 55AXP", manufactured by AGC Inc., melting point 260°C) with copper phthalocyanine blue (product name "Chromofine Blue", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), phenylmethyl silicone oil (product name "KF54", manufactured by Shin-Etsu Chemical Co., Ltd.), and carbon black (product name "Denka Black Granules", manufactured by Denka Company Ltd.). The blending amounts of copper phthalocyanine blue pigment and carbon black were set so that their respective concentrations (% by mass) in 100% by mass of the blend were the concentrations (% by mass) shown in Table 1. The blending amount of phenylmethyl silicone oil was set so that its concentration in 100% by mass of the blend was 0.001% by mass. Thereafter, in the same manner as in Example 1, the above blend was pelletized using a twin-screw extruder and formed into a film using a single-screw extruder. The films of Examples 7, 8, 10, and 11 all exhibited a low-saturation blue color. The film of Example 9 exhibited a black color. In Example 7, the mass of carbon black per unit area of ​​the film was 0.017 g / m2, since the specific gravity of ETFE was 1.75 and the film thickness was 250 μm. 2 The mass of carbon black per unit area of ​​the other films is shown in Table 1. The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the films are shown in Table 2.

[0097] [Example 12] A film was obtained in the same manner as in Example 1, except that the blending amounts of copper phthalocyanine blue and phenylmethyl silicone oil were changed so that the respective concentrations in 100% by mass of the blend were 0.24% by mass and 0.02% by mass. The resulting film was deep blue. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0098] [Example 13] A blend was obtained by blending ETFE (product name "Fluon ETFE 55AXP", manufactured by AGC Inc., melting point 260°C) with copper phthalocyanine green (product name "Chromofine Green", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), phenylmethyl silicone oil (product name "KF54", manufactured by Shin-Etsu Chemical Co., Ltd.), and carbon black (product name "Denka Black Granules", manufactured by Denka Company Ltd.). The blending amounts of copper phthalocyanine green, phenylmethyl silicone oil, and carbon black were set so that their respective concentrations in 100% by mass of the blend were 0.030%, 0.001%, and 0.0054% by mass. Thereafter, in the same manner as in Example 1, the above blend was pelletized using a twin-screw extruder and formed into a film using a single-screw extruder. The resulting film was greenish-black. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0099] [Example 14] A compound was obtained in the same manner as in Example 13, except that carbon black was not added. Thereafter, the mixture was pelletized in a twin-screw extruder and formed into a film in a single-screw extruder in the same manner as in Example 1. The obtained ETFE film showed a bright green color. Subsequently, in the same manner as in Example 2, a thin chromium film having a thickness of 8 nm was formed on the ETFE film, and the resulting laminate was used as the film of Example 14. The resulting film exhibited a low-saturation green-black color. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0100] [Example 15] In the same manner as in Example 14, an 8 nm-thick chromium thin film was formed on an ETFE film. Subsequently, aluminum was used as the target, and Ar gas was introduced into the chamber at 50 sccm and O gas at 3 sccm, and discharge was performed at a DC voltage of 320 V. A 20 nm-thick aluminum oxide thin film (dry protective layer) was formed on the chromium thin film by opening and closing the shutter to control the film formation time. The resulting laminate was designated the film of Example 15. The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the film are shown in Table 2.

[0101] [Example 16] A wet protective layer was formed on the thin chromium film of the laminate obtained in Example 14 in the same manner as in Example 3, and the resulting laminate was used as the film of Example 16. The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the film are shown in Table 2.

[0102] [Example 17] A laminate was produced in the same manner as in Example 14 except that the thickness of the chromium thin film was changed to 4 nm, and this laminate was used as the film of Example 17. The resulting film exhibited a low-saturation green-black color. Table 1 shows the composition of the film materials, and Table 2 shows the optical properties and evaluation results of the film.

[0103] [Example 18] A 4 nm-thick thin chromium film was formed on the ETFE film in the same manner as in Example 17. Subsequently, a 20 nm-thick thin aluminum oxide film (dry protective layer) was formed on the thin chromium film in the same manner as in Example 15. The resulting laminate was designated as the film of Example 18. The composition of the film materials is shown in Table 1, and the optical properties and evaluation results of the film are shown in Table 2.

[0104] [Example 19] A blend was obtained by blending ETFE (product name "Fluon ETFE 55AXP" manufactured by AGC Inc., melting point 260°C) with aluminum-cobalt composite oxide (product name "Co Blue P" manufactured by Asahi Chemical Industries Co., Ltd.), phenylmethyl silicone oil (product name "KF54" manufactured by Shin-Etsu Chemical Co., Ltd.), and carbon black (product name "Denka Black Granules" manufactured by Denka Company Limited). The blend amounts of aluminum-cobalt composite oxide, phenylmethyl silicone oil, and carbon black were set so that their respective concentrations in the 100% blend were 0.060%, 0.01%, and 0.01% by mass. The blend was then pelletized using a twin-screw extruder and filmed using a single-screw extruder in the same manner as in Example 1. The resulting film was bluish-black. Table 1 shows the composition of the film's materials, and Table 2 shows the optical properties and evaluation results of the film.

[0105] [Example 20] A film was obtained in the same manner as in Example 19, except that the amount of aluminum-cobalt composite oxide was changed so that the concentration in 100 mass% of the blend was 0.50 mass%. The resulting film was bluish-black. Table 1 shows the composition of the film's materials, and Table 2 shows the optical properties and evaluation results of the film.

[0106] [Table 1]

[0107] [Table 2]

[0108] In Table 1, "concentration (%)" indicates the content (mass %) of the chromatic pigment or black pigment in 100 mass % of the fluororesin layer. 2 )" indicates the content of chromatic pigment or black pigment per unit area of ​​the fluororesin layer. "CB" stands for carbon black.

[0109] The appearance of the films of Examples 2 to 8, 10, 11, and 13 to 19 was heavy. On the other hand, the film of Example 1 did not contain a black pigment and therefore did not have a heavy feel, which was thought to be because the color tone of the film was a light blue, not a dark color. The film of Example 9 had a visible light transmittance of less than 5% and a haze of more than 30%, and therefore lacked a sense of solidity. The film of Example 12 did not contain a black pigment and had a haze of over 30%, so it lacked a sense of depth. The film of Example 20 had a haze of more than 30% and therefore lacked a sense of depth. Comparing Examples 2 and 3, Examples 4 and 5, Examples 14, 15 and 16, and Examples 17 and 18, it was confirmed that Examples 3, 5, 15, 16 and 18, which have protective layers, have excellent abrasion resistance while ensuring adhesion. [Industrial Applicability]

[0110] The film of the present disclosure has a solid, glass-like appearance, making it useful as a film for membrane structures. [Explanation of symbols]

[0111] 1...film, 2...film, 2A...film, 3...fluororesin, 5...chromatic pigment, 7...black pigment, 10...fluororesin layer, 21...fluororesin layer, 23...black pigment layer, 25...protective layer

Claims

1. The ink contains a fluororesin, a chromatic pigment, and a black pigment, The visible light transmittance is 5 to 60%, The haze is 30% or less, a fluororesin layer containing the fluororesin and the chromatic color pigment, and a layer containing the black pigment, A film, wherein the content of the black pigment in the layer containing the black pigment is 90 mass % or more.

2. 2. The film of claim 1, wherein the thickness of the layer containing the black pigment is 0.5 to 50 nm.

3. 3. The film according to claim 1, wherein the layer containing the black pigment is a layer formed by a dry process.

4. The film according to any one of claims 1 to 3, wherein the black pigment comprises at least one selected from the group consisting of metals and alloys.

5. The film according to any one of claims 1 to 4, wherein the black pigment comprises at least one selected from the group consisting of chromium, chromium alloys, nickel, nickel alloys, titanium, titanium alloys, zinc, zinc alloys, indium, and indium alloys.

6. The film according to any one of claims 1 to 5, further comprising a protective layer on the layer containing the black pigment.

7. 7. The film according to claim 6, wherein the protective layer is a layer formed from a fluororesin having a reactive functional group, or a layer formed from at least one inorganic material selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides.

8. The content of the chromatic pigment per unit area of ​​the fluororesin layer is 0.030 to 0.80 g / m ２ The film according to any one of claims 1 to 7, wherein

9. The film of any one of claims 1 to 8, wherein the chromatic pigment has a blue or green hue.

10. The film according to any one of claims 1 to 9, wherein the fluororesin comprises at least one selected from the group consisting of vinyl fluoride polymer, vinylidene fluoride polymer, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-vinylidene fluoride-propylene copolymer, ethylene-tetrafluoroethylene copolymer, hexafluoropropylene-tetrafluoroethylene copolymer, ethylene-hexafluoropropylene-tetrafluoroethylene copolymer, perfluoro(alkyl vinyl ether)-tetrafluoroethylene copolymer, chlorotrifluoroethylene polymer, and ethylene-chlorotrifluoroethylene copolymer.

11. The film according to any one of claims 1 to 10, which is a film for a membrane structure.

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