WO2011096151A1

WO2011096151A1 - Film mirror and process for production thereof, and sunlight collection mirror

Info

Publication number: WO2011096151A1
Application number: PCT/JP2010/073496
Authority: WO
Inventors: 美佳本田
Original assignee: コニカミノルタオプト株式会社
Priority date: 2010-02-04
Filing date: 2010-12-27
Publication date: 2011-08-11
Also published as: JPWO2011096151A1

Abstract

A film mirror having a sunlight-reflecting function, which comprises a polymer film layer, a gas barrier layer containing a metal oxide, and a reflective metal layer in this order from the sunlight incident side, and which is characterized in that the ratio of the thickness of the gas barrier layer to the thickness of the polymer film layer is 0.1 to 5%; a process for producing the film mirror; and a sunlight collection mirror.

Description

Film mirror, manufacturing method thereof, and solar light collecting mirror

The present invention relates to a film mirror, and more particularly to a film mirror for collecting sunlight.

In recent years, biomass energy, nuclear energy, and natural energy such as wind energy and solar energy have been studied as alternative energy to replace fossil fuel energy such as coal energy, oil, and natural gas. The most stable and large amount of natural energy is considered to be solar energy.

However, although solar energy is a very powerful alternative energy, from the viewpoint of utilizing this, (1) the energy density of solar energy is low, and (2) it is difficult to store and transfer solar energy. However, this is considered a problem.

On the other hand, it has been proposed to solve the problem of low energy density of solar energy by collecting solar energy with a huge reflector.

Since the reflecting device is exposed to sunlight, ultraviolet rays, heat, wind and rain, sandstorms, etc., a glass mirror has been conventionally used. Glass mirrors are highly durable against the environment, but they have the problem of impact properties such as breakage during transportation, and the strength of the frame on which the heavy mirrors are installed increases the construction cost of the plant.

Therefore, in order to solve the above problem, a film mirror in which the reflective layer is made of silver and the surface sealing layer made of glass is replaced with a polymer film made of resin has been proposed (see, for example, Patent Documents 1 and 2). It was. The polymer film is known to be deteriorated by sunlight, particularly ultraviolet rays having a wavelength of 380 nm or less. As a countermeasure, the polymer films described in Patent Document 1 and Patent Document 2 are blended with an ultraviolet absorber. When the regular reflectance of these film mirrors is measured in the range of 2500 nm to 250 nm with a spectrophotometer, the reflectance in the infrared region having a wavelength longer than 1600 nm is lower than the reflectance of silver itself in addition to the ultraviolet region reflectance. It was seen. (125 μm PET / Ag in FIG. 2) This absorption in the infrared region is due to vibration absorption of the polymer and is inherent to the resin material.

As shown in FIG. 1, the irradiation spectrum of sunlight is observed from 2500 nm. When using solar energy for thermoelectric power generation, if the surface sealing layer has absorption in the infrared region of 1600 nm to 2500 nm, the thermoelectric power generation efficiency is lowered, which is not preferable. Furthermore, this polymer film is more permeable to gases such as oxygen and water vapor than glass, and in an environment exposed to rain and dew, it penetrates into the metal reflective layer over time. Although the gas diffusion coefficient D is different for each polymer film, the diffusion time is proportional to the thickness of the polymer film, and the thicker the film, the slower the gas permeation that degrades the metal reflective layer, so the service life is become longer. However, when the thickness of the polymer film is increased, the above-described absorption cross-sectional area in the infrared region is increased, so that the thermoelectric generation efficiency is lowered. Improving durability and maintaining thermoelectric efficiency was a trade-off.

Therefore, an injection-molded plastic mirror has been developed in which a metal reflective layer is coated with a metal oxide on the surface of a resin substrate (see, for example, Patent Document 3). This injection-molded plastic mirror had a high reflectance of 90% or more on average from the ultraviolet region to the infrared region. Therefore, in order to correspond to a large-area mirror, in Patent Document 2, a film mirror having a structure in which a silver mirror is formed on the surface of a polymer film and the surface is covered with a metal oxide is manufactured. However, it was found that when the structure in which the metal oxide is arranged on the outermost surface is applied to the film, the metal oxide cracks when the film is bent. The technique of Patent Document 3 has no problem with an injection-molded plastic mirror, but cannot be applied to a roll-to-roll system for producing a large-area film. It turns out that oxygen and water vapor enter from the generated crack, and the metal reflective film is corroded. It was found that the metal oxide coated film mirror once cracked was not durable.

Japanese Patent No. 3447175 Special table 2009-520174 Japanese Patent No. 3206957

An object of the present invention is to provide a film mirror capable of improving durability and maintaining thermoelectric generation efficiency for a long period of time, and further providing a film mirror for collecting sunlight using the film mirror.

The above object of the present invention can be achieved by the following configuration.

1. A film mirror in which a polymer film layer, a gas barrier layer having a metal oxide, and a metal reflection layer are arranged in this order from the sunlight incident side, the thickness of the gas barrier layer with respect to the polymer film layer A film mirror having a function of reflecting sunlight, wherein the ratio is in the range of 0.1% to 5%.

2. 2. The film mirror as described in 1 above, wherein the film thickness of the polymer film layer is in the range of 10 μm to 125 μm.

3. 3. The film mirror as described in 1 or 2 above, wherein the metal oxide of the gas barrier layer is at least one selected from silicon oxide, aluminum oxide, and a mixture of two types of silicon oxide and aluminum oxide.

4. 4. The film mirror according to claim 1, wherein the metal of the reflective layer is silver.

5. 5. The film mirror according to any one of 1 to 4, wherein the metal reflective layer is formed by wet plating.

6. 5. The film mirror according to claim 1, wherein the metal reflective layer is produced by dry plating.

7. 7. The film mirror as described in any one of 1 to 6 above, wherein the polymer film layer contains an ultraviolet absorber.

8. In contact with the metal reflective layer, at least one selected from thioether, thiol, Ni organic compound, benzotriazole, imidazole, oxazole, tetrazaindene, pyrimidine, and thiadiazole 8. The film mirror as described in any one of 1 to 7 above, wherein a corrosion inhibitor layer to be contained is provided.

9. 9. The film mirror according to claim 1, wherein a Cu layer is provided in contact with the metal reflective layer.

10. 10. The film mirror according to claim 1, wherein the film mirror has an adhesive layer on the side opposite to the side on which sunlight is incident.

11. 11. The film mirror manufacturing method according to claim 1, wherein the metal reflective layer is formed by silver vapor deposition.

12. 11. A solar light collecting mirror, wherein the film mirror according to 10 is formed on a support through an adhesive layer of the film mirror.

By the above means of the present invention, it is possible to prevent a decrease in regular reflectance due to deterioration of the metal reflective layer, and to be light and flexible, lightweight and flexible, and can be manufactured in a large area and mass-produced with reduced manufacturing costs. The film mirror which is excellent and has a good regular reflectance with respect to sunlight, its manufacturing method, and the film mirror for sunlight condensing using the same were able to be provided.

According to the present invention, by providing a gas barrier layer having a polymer film layer and a metal oxide so as to cover the reflective layer of metal, the gas barrier property can be imparted, the service life can be extended, and the replacement cost can be reduced. it can. Compared with a conventional polymer film-covered film mirror, the absorption in the infrared region can be reduced, and the thermoelectric generation efficiency can be improved.

It is a figure which shows the irradiation spectrum range of sunlight. It is a figure which shows the spectral reflectance of a mirror. It is sectional drawing which shows an example of the typical film mirror of this invention.

In view of the above problems, the present invention improves the impact resistance by coating a metal oxide film with a high molecular weight polymer instead of forming a metal oxide film on the high molecular weight polymer. Molecular polymers are thinned in a direction that reduces absorption in the infrared region. As the polymer film is made thinner, a metal oxide film with a gas barrier function is attached to improve durability and maintain thermoelectric generation efficiency.

According to one aspect of the present invention, a) a polymer film layer in order from the sunlight incident side,
b) a gas barrier layer comprising a metal oxide,
c) The above effect was achieved by a film mirror in which a metal reflective layer was disposed and the thickness ratio of b) to a) was in the range of 0.1% to 5%.

Hereinafter, the best mode for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a cross-sectional view showing an example of a film mirror having a function of reflecting sunlight according to the present invention.

As shown in FIG. 3, the film mirror F has a polymer film layer 1, a gas barrier layer 2 having a metal oxide, a metal reflection layer (Ag layer) 3, and an adhesive layer 4 laminated in order from the sunlight side. Become. A release film 5 can be attached to the lower surface of the adhesive layer 4 and the release film 5 can be appropriately peeled off when desired to adhere to a metal plate or resin plate as a support.

The film mirror of the present invention is not limited to the configuration shown in FIG. 3, and it is preferable to add various functional layers. Moreover, even if it is the said structure, functionality can be provided to each layer. Hereinafter, embodiments of the present invention to which a functional layer is added will be described. Further, the present invention is not limited only to these embodiments. Furthermore, in the following description, the upper side means the side on which sunlight is incident, and the lower side means the opposite side.

In FIG. 3, an ultraviolet absorber is added to the polymer film layer 1 so that the gas barrier layer 2 below functions as a water vapor barrier layer, and the reflective layer 3 therebelow is composed of a silver vapor deposition layer. Let the film mirror which has the structure which laminated | stacked the adhesion layer 4 and the peeling film 5 below be the film mirror 1 of this invention. The durability increases by adding an ultraviolet absorber to the polymer film layer.

In the film mirror 1, a film mirror provided with a corrosion inhibitor layer (a polymer layer containing a corrosion inhibitor) between the reflective layer 3 and the adhesive layer 4 is referred to as a film mirror 2 of the present invention. By adding a corrosion inhibitor layer, deterioration of oxygen, hydrogen sulfide gas and salt content of the film mirror and a smooth optical surface can be provided for a long time.

In the film mirror 1, an adhesive layer and a corrosion inhibitor layer are laminated in order from the side where sunlight enters between the gas barrier layer 2 and the reflective layer 3, and further, a high layer is formed between the reflective layer 3 and the adhesive layer 4. Let the film mirror which provided the molecular film layer be the film mirror 3 of this invention.

In the film mirror 2, instead of the polymer film layer 1 to which the ultraviolet absorber is added, a film mirror in which a hard coat layer and a polymer film layer are laminated in order from the sunlight incident side is used as the film mirror of the present invention. 4. The hard coat layer preferably contains an ultraviolet absorber or the like.

In the above film mirror 4, a film mirror in which an ultraviolet reflecting layer is provided on a polymer film layer instead of a hard coat layer is referred to as a film mirror 5 of the present invention.

In the film mirror 2, a film mirror provided with a sacrificial anticorrosive layer instead of the corrosion inhibitor layer is referred to as a film mirror 6 of the present invention.

Subsequently, each layer of the film mirror of the present invention and materials used for each layer will be described.

(Polymer film layer)
The film material of the polymer film layer preferably contains, for example, polyester, polyethylene terephthalate, polyethylene naphthalate, acrylic, polycarbonate, polyolefin, cellulose, or polyamide from the viewpoint of flexibility and weight reduction. Among these, an acrylic copolymer excellent in weather resistance and particularly copolymerized with at least two kinds of acrylic monomers is preferable.

Specific examples of suitable acrylic copolymers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. One or more monomers selected from monomers having no functional group in the side chain (hereinafter referred to as non-functional monomers) such as alkyl (meth) acrylates such as cyclohexyl methacrylate and 2-ethylhexyl methacrylate As a main component, one or more kinds of monomers selected from monomers such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, etc. A monomer having a functional group such as OH or COOH in the side chain of the mer (hereinafter referred to as a functional monomer) or a combination of two or more thereof, solution polymerization, suspension polymerization, emulsion polymerization, bulk Examples include acrylic copolymers having a weight average molecular weight of 40,000 to 1,000,000, preferably 100,000 to 400,000, obtained by copolymerization by a polymerization method such as a polymerization method. Among them, ethyl acrylate, methyl acrylate, -50 to 90% by weight of non-functional monomer that gives a relatively low Tg polymer such as ethylhexyl methacrylate, and 10 to 50 non-functional monomer that gives a relatively high Tg polymer such as methyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, etc. Mass%, 2-hydroxyethyl methacrylate, acrylic acid, itacone Acrylic polymers such as the functional monomer contains 0 to 10% by weight of an equal is most preferred.

The shape of the film may be a shape required as a surface covering material for various film mirrors such as a flat surface, a diffusion surface, a concave surface, a convex surface, and a trapezoid.

The thickness of the film substrate is preferably 10 to 125 μm. If it is thinner than 10 μm, the film will not be stiff, and the film will be wrinkled easily, which is not preferable in appearance and tends to deteriorate the reflection performance. If it is thicker than 125 μm, the average reflectance in the range of 1600 nm to 2500 nm is less than 80%. .

The surface of the polymer film layer may be subjected to corona discharge treatment, plasma treatment or the like in order to improve adhesion with a metal oxide layer, a hard coat layer, a dielectric coating layer, or the like.

Further, it is preferable that the film base material contains any one of benzotriazole, benzophenone, triazine, cyanoacrylate, and polymer type ultraviolet absorbers.

(UV absorber)
As the ultraviolet absorber used for the polymer film layer, an ultraviolet absorbent having a wavelength of 370 nm or less and excellent absorption of ultraviolet rays and having a small absorption of visible light having a wavelength of 400 nm or more is preferable from the viewpoint of utilization of sunlight.

Examples of the ultraviolet absorber used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. However, benzophenone compounds, less colored benzotriazole compounds, and triazine compounds are preferable. Further, ultraviolet absorbers described in JP-A Nos. 10-182621 and 8-337574, and polymer ultraviolet absorbers described in JP-A Nos. 6-148430 and 2003-113317 may be used.

Specific examples of benzotriazole ultraviolet absorbers include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzo Triazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5 Chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy 3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5 '-(2-octyloxycarbonylethyl) -phenyl)- 5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5 ′-(1,1,3,3-tetramethylbutyl) -phenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H -Benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro- H- benzotriazol-2-yl) can be mentioned mixtures of phenyl] propionate, and the like.

As commercially available products, TINUVIN 171, TINUVIN 900, TINUVIN 928, TINUVIN 360 (all manufactured by BASF Japan), LA31 (manufactured by ADEKA), RUVA-100 (Otsuka) Chemical).

Specific examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy-) 5-benzoylphenylmethane) and the like, but are not limited thereto.

(Gas barrier layer with metal oxide)
Examples of the gas barrier layer having a metal oxide include silicon oxide, aluminum oxide, or silicon oxide, a composite oxide starting from aluminum oxide, zinc oxide, tin oxide, indium oxide, niobium oxide, chromium oxide, etc. From the viewpoint of water vapor barrier properties, silicon oxide, aluminum oxide, or a composite oxide starting from silicon and aluminum is preferable. In addition, a multilayer film in which a low refractive index layer having a refractive index of 1.35 to 1.8 at a wavelength of 550 nm and a high refractive index film having a refractive index of 1.85 to 2.8 at a wavelength of 550 nm are alternately laminated. Also good. Examples of the low refractive index film material include silicon oxide, aluminum oxide, silicon nitride, and aluminum nitride. Examples of the high refractive index film material include niobium oxide, titanium oxide, zinc oxide, tin oxide, indium oxide, tantalum oxide, and zirconium oxide. These are formed by a vacuum process such as a vacuum deposition method, a sputtering method, a PVD method (physical vapor deposition method) such as ion plating, or a CVD method (chemical vapor deposition method). The thickness of the gas barrier layer having a metal oxide is preferably in the range of 5 to 800 nm, more preferably in the range of 10 to 300 nm.

In the method of the present invention, a gas barrier layer is formed on a polymer film, and thus a silicon oxide layer or an aluminum oxide layer obtained as described above, or a composite oxide layer using silicon oxide and aluminum oxide as a starting material is oxygenated. Excellent barrier action against gas such as carbon dioxide, air, or water vapor.

In addition, a laminate of a silicon oxide layer or an aluminum oxide layer, or a composite oxide layer starting from silicon oxide or aluminum oxide and a polymer film has a water vapor permeability of 1 × 10 ^{−2 at} 40 ° C. and 90% RH. It is preferably g / m ² · 24 h or less. The water vapor transmission rate can be measured with a water vapor transmission rate measuring device PERMATRAN-W3-33 manufactured by MOCON.

Further, the silicon oxide layer or the aluminum oxide layer, or the composite oxide layer using silicon oxide and aluminum oxide as a starting material has a thickness of 1 μm or less, and the average value of each light transmittance is 90% or more. It is preferable. Thereby, there is no light loss and sunlight can be reflected efficiently.

(Ratio of the thickness of the gas barrier layer having the polymer film layer and the metal oxide)
In the present invention, the ratio of the thickness of the polymer film layer and the gas barrier layer having a metal oxide is in the range of 0.1% to 5%. When the ratio is smaller than 0.1%, that is, when the thickness of the gas barrier layer with respect to the polymer film becomes thin, sufficient gas barrier properties cannot be obtained and the function of suppressing the progress of deterioration cannot be exhibited. When the ratio is larger than 5%, that is, when the thickness of the gas barrier layer with respect to the polymer film is increased, the metal oxide cracks when an external bending force is applied, and as a result, the gas barrier property cannot be obtained and the deterioration progresses. The function to suppress is not demonstrated.

(Metal reflective layer)
As the metal reflective layer according to the present invention, for example, silver or a silver alloy, gold, copper, aluminum, or an alloy thereof can be used. In particular, it is preferable to use silver. Such a reflective layer serves as a reflective film that reflects light. By making the reflective layer a silver or silver alloy film, the reflectance of the film mirror from the infrared region to the visible light region can be increased, and the dependency of the reflectance on the incident angle can be reduced. From the infrared region to the visible light region means a wavelength region of 2500 to 400 nm. The incident angle means an angle with respect to a line (normal line) perpendicular to the film surface.

As the silver alloy, there is an alloy of silver and one or more other metals selected from the group consisting of gold, palladium, tin, gallium, indium, copper, titanium and bismuth because the durability of the reflective layer is improved. preferable. As the other metal, gold is particularly preferable from the viewpoint of high temperature humidity resistance and reflectance.

When the reflective layer is a silver alloy film, silver is preferably 90 to 99.8 atomic% in the total (100 atomic%) of silver and other metals in the reflective layer. Further, the other metal is preferably 0.2 to 10 atomic% from the viewpoint of durability.

The film thickness of the reflective layer is preferably 60 to 300 nm, particularly preferably 80 to 200 nm. If the thickness of the reflective layer is less than 60 nm, the film thickness is thin and light is transmitted, so that the reflectance in the visible light region of the film mirror may be reduced. The reflectance increases in proportion to the film thickness up to about 200 nm, but it does not depend on the film thickness above 200 nm. Rather, when the thickness of the reflective layer exceeds 300 nm, irregularities are likely to occur on the surface of the reflective layer, which causes light scattering, which may reduce the reflectance in the visible light region.

Film mirrors are required to be glossy, but the method of making and bonding metal foils loses gloss due to surface irregularities. For film mirrors that require uniform surface roughness over a wide area, metal foil lamination is not preferred as a manufacturing method. The metal reflection layer is preferably formed by wet plating or dry plating such as vacuum deposition.

(Adhesive layer)
The pressure-sensitive adhesive layer of the present invention is not particularly limited, and for example, any of a dry laminating agent, a wet laminating agent, a heat seal agent, a hot melt agent and the like are used. For example, polyester resin, urethane resin, polyvinyl acetate resin, acrylic resin, nitrile rubber, etc. are used. The laminating method is not particularly limited, and for example, it is preferable to carry out continuously by a roll method from the viewpoint of economy and productivity. The thickness of the adhesive layer is usually selected from the range of about 1 to 50 μm. When the thickness is less than 1 μm, a sufficient adhesive effect cannot be obtained. On the other hand, when the thickness exceeds 50 μm, the pressure-sensitive adhesive layer is too thick and the drying speed is slow, which is inefficient. In addition, the original adhesive strength cannot be obtained, and adverse effects such as residual solvent occur, which is not preferable.

(Peeling film)
The release film that can be used in the present invention has a base material and a release agent layer provided on the base material.

¡The outer surface of the release film has high smoothness. Examples of the release agent constituting the release film include silicone resins, long-chain alkyl resins, fluorine resins, fluorosilicone resins, long-chain alkyl-modified alkyd resins, silicone-modified alkyd resins, and the like. .

Among the above, when a silicone resin is used as a material for the release agent, more excellent release properties are exhibited. As the silicone resin, any of addition type, condensation type, solventless type and the like can be used.

The average thickness of the release agent constituting the release film is not particularly limited, but is preferably 0.01 to 0.3 μm, and more preferably 0.05 to 0.2 μm. When the average thickness of the release agent layer is less than the lower limit, the function as the release agent layer may not be sufficiently exhibited. On the other hand, if the average thickness of the release agent layer exceeds the upper limit, blocking may occur when the release film is wound into a roll, resulting in a failure in feeding.

The total thickness of the film mirror according to the present invention is preferably 75 to 250 μm, more preferably 90 to 230 μm, still more preferably 100 to 220 μm. When the thickness is 75 μm or less, when the film mirror is attached to the metal substrate, the mirror is bent and sufficient regular reflectance cannot be obtained, and when it is thicker than 250 μm, the handleability is deteriorated. It is not preferable.

(Corrosion inhibitor layer)
The corrosion inhibitor layer installed on the film mirrors 2 to 5 described above as an embodiment of the present invention functions to prevent discoloration of a metal reflection layer (specifically, an Ag layer), for example, a thioether type, a thiol type, a Ni type Organic compound type, benzotriazole type, imidazole type, oxazole type, tetrazaindene type, pyrimidine type, and thiadiazole type are mentioned.

The corrosion inhibitor layer is roughly classified into a corrosion inhibitor having an adsorption group with silver and an antioxidant. Specific examples of these corrosion inhibitors and antioxidants are given below.

<< Corrosion inhibitor with adsorption group with silver >>
Corrosion inhibitors having an adsorption group with silver include amines and derivatives thereof, products having a pyrrole ring, products having a triazole ring, products having a pyrazole ring, products having a thiazole ring, products having an imidazole ring, indazole It is desirable to be selected from a ring-containing product, a copper chelate compound, a thiourea, a product having a mercapto group, at least one naphthalene-based compound, or a mixture thereof.

Examples of amines and derivatives thereof include ethylamine, laurylamine, tri-n-butylamine, o-toluidine, diphenylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, monoethanolamine, diethanolamine, triethanolamine, 2N- Dimethylethanolamine, 2-amino-2-methyl-1,3-propanediol, acetamide, acrylamide, benzamide, p-ethoxychrysoidine, dicyclohexylammonium nitrite, dicyclohexylammonium salicylate, monoethanolamine benzoate, dicyclohexylammonium benzoate, diisopropyl Ammonium benzoate, diisopropylammonium nitrite , Cyclohexylamine carbamate, nitronaphthalene nitrite, cyclohexylamine benzoate, dicyclohexylammonium cyclohexanecarboxylate, cyclohexylamine cyclohexane carboxylate, dicyclohexylammonium acrylate, cyclohexylamine acrylate, or mixtures thereof.

Examples of the compound having a pyrrole ring include N-butyl-2,5-dimethylpyrrole, N-phenyl-2,5dimethylpyrrole, N-phenyl-3-formyl-2,5-dimethylpyrrole, N-phenyl-3, 4-diformyl-2,5-dimethylpyrrole, etc., or a mixture thereof.

Examples of the compound having a triazole ring include 1,2,3-triazole, 1,2,4-triazole, 3-mercapto-1,2,4-triazole, 3-hydroxy-1,2,4-triazole, 3- Methyl-1,2,4-triazole, 1-methyl-1,2,4-triazole, 1-methyl-3-mercapto-1,2,4-triazole, 4-methyl-1,2,3-triazole, Benzotriazole, tolyltriazole, 1-hydroxybenzotriazole, 4,5,6,7-tetrahydrotriazole, 3-amino-1,2,4-triazole, 3-amino-5-methyl-1,2,4- Triazole, carboxybenzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy- '-Tert-butylphenyl) benzotriazole, 2- (2'-hydroxy3'5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-4-octoxyphenyl) benzotriazole, etc. Alternatively, a mixture thereof can be mentioned.

Examples of the compound having a pyrazole ring include pyrazole, pyrazoline, pyrazolone, pyrazolidine, pyrazolidone, 3,5-dimethylpyrazole, 3-methyl-5-hydroxypyrazole, 4-aminopyrazole and the like, or a mixture thereof.

Examples of those having a thiazole ring include thiazole, thiazoline, thiazolone, thiazolidine, thiazolidone, isothiazole, benzothiazole, 2-N, N-diethylthiobenzothiazole, P-dimethylaminobenzallodanine, 2-mercaptobenzothiazole, etc. Or a mixture thereof.

Examples of compounds having an imidazole ring include imidazole, histidine, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methyl Imidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecyl Imidazole, 2-phenyl-4-methyl-5-hydromethylimidazole, 2-phenyl-4,5 dihydroxymethylimidazole, 4-formylimidazole, 2-methyl-4-formylimidazole, 2-phenyl-4-phospho Myrimidazole, 4-methyl-5-formylimidazole, 2-ethyl-4-methyl-5-formylimidazole, 2-phenyl-4-methyl-4-formylimidazole, 2-mercaptobenzimidazole, etc., or these Of the mixture.

Examples of the compound having an indazole ring include 4-chloroindazole, 4-nitroindazole, 5-nitroindazole, 4-chloro-5-nitroindazole, and the like, or a mixture thereof.

Examples of copper chelate compounds include acetylacetone copper, ethylenediamine copper, phthalocyanine copper, ethylenediaminetetraacetate copper, hydroxyquinoline copper, and the like, or a mixture thereof.

Examples of thioureas include thiourea, guanylthiourea, and the like, or a mixture thereof.

As a product having a mercapto group, mercaptoacetic acid, thiophenol, 1,2-ethanediol, 3-mercapto-1,2,4-triazole, 1-methyl-3-mercapto are added if the above-mentioned materials are added. -1,2,4-triazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, glycol dimercaptoacetate, 3-mercaptopropyltrimethoxysilane, etc., or a mixture thereof.

Examples of naphthalene-based compounds include thionalide.

"Antioxidant"
As the antioxidant that can be used in the corrosion inhibitor layer according to the present invention, it is preferable to use a phenol-based antioxidant, a thiol-based antioxidant, and a phosphite-based antioxidant. Examples of phenolic antioxidants include 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 2,2′-methylenebis (4-ethyl-6-t- Butylphenol), tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 2,6-di-t-butyl-p-cresol, 4,4 '-Thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 1,3,5-tris (3', 5'-di-t -Butyl-4'-hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ,bird Tylene glycol bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-di-methyl-2- [β- (3-t-butyl -4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene and the like.

In particular, the phenolic antioxidant preferably has a molecular weight of 550 or more. Examples of the thiol antioxidant include distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), and the like. Examples of the phosphite antioxidant include tris (2,4-di-t-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, di (2,6-di-t-butylphenyl) pentaerythritol. Diphosphite, bis- (2,6-di-t-butyl-4-methylphenyl) -pentaerythritol diphosphite, tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylene-diphosphonite 2,2′-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and the like.

In the film mirror 3 according to the embodiment of the present invention, a metal reflective layer is formed on the surface of the polymer film (A), and a corrosion inhibitor layer is further laminated thereon. After laminating the adhesive layer and the release film on the lower surface of the polymer film (A), an adhesive layer is formed on the surface of the polymer film (A), that is, on the corrosion inhibitor layer. A gas barrier layer is formed on the lower surface of another polymer film (B), and the gas barrier layer of the polymer film (B) and the adhesive layer of the polymer film (A) are faced to each other to produce them.

(Adhesive layer)
As an adhesive layer installed in the film mirror 3 of the aspect of this invention, it consists of resin and adheres a film and the polymer film layer containing the above-mentioned ultraviolet absorber. Therefore, the adhesive layer needs to have an adhesive property for closely adhering the film and the ultraviolet absorber-containing polymer film layer, and smoothness and transparency to bring out the high reflection performance inherent to the metal reflective layer.

The resin used for the adhesive layer is not particularly limited as long as it satisfies the above conditions of adhesion, heat resistance, and smoothness. Polyester resin, acrylic resin, melamine resin, epoxy resin, polyamide Resin, vinyl chloride resin, vinyl chloride vinyl acetate copolymer resin or the like, or a mixed resin thereof can be used. From the viewpoint of weather resistance, a polyester resin and a melamine resin mixed resin are preferable. It is more preferable to use a thermosetting resin mixed with a curing agent.

The thickness of the adhesive layer is preferably 0.01 to 3 μm, more preferably 0.1 to 1 μm. If the thickness is less than 0.01 μm, the adhesiveness is deteriorated and there is no effect of forming an adhesive layer, and it is difficult to cover the unevenness on the surface of the film substrate, and the smoothness is deteriorated. Even if the thickness is greater than 3 μm, improvement in adhesion cannot be expected, and on the contrary, unevenness of coating may cause poor smoothness or insufficient curing of the adhesive layer, which is not preferable.

As a method for forming the adhesive layer, conventionally known coating methods such as a gravure coating method, a reverse coating method, and a die coating method can be used.

(Hard coat layer)
In the present invention, a hard coat layer can be provided as the outermost layer of the film mirror. The hard coat layer is provided for preventing scratches. As an aspect using a hard-coat layer, the film mirror 4 mentioned above can be mentioned.

The hard coat layer can be composed of acrylic resin, urethane resin, melamine resin, epoxy resin, organic silicate compound, silicone resin, and the like. In particular, silicone resins and acrylic resins are preferable in terms of hardness and durability. Furthermore, an active energy ray-curable acrylic resin or a thermosetting acrylic resin is preferable in terms of curability, flexibility, and productivity.

The active energy ray-curable acrylic resin or thermosetting acrylic resin is a composition containing a polyfunctional acrylate, an acrylic oligomer, or a reactive diluent as a polymerization curing component. In addition, you may use what contains a photoinitiator, a photosensitizer, a thermal-polymerization initiator, a modifier, etc. as needed.

Acrylic oligomers include polyester acrylates, urethane acrylates, epoxy acrylates, polyether acrylates, etc., including those in which a reactive acrylic group is bonded to an acrylic resin skeleton, and rigid materials such as melamine and isocyanuric acid. A structure in which an acrylic group is bonded to a simple skeleton can also be used.

In addition, the reactive diluent has a function of a solvent in the coating process as a medium of the coating agent, and has a group that itself reacts with a monofunctional or polyfunctional acrylic oligomer. It becomes a copolymerization component.

Commercially available polyfunctional acrylic cured paints include Mitsubishi Rayon Co., Ltd. (trade name “Diabeam (registered trademark)” series, etc.), Nagase Sangyo Co., Ltd. (trade name “Denacol (registered trademark)” series, etc. ), Shin-Nakamura Co., Ltd. (trade name “NK Ester” series, etc.), Dainippon Ink and Chemicals Co., Ltd .; (trade name “UNIDIC (registered trademark)” series, etc.), Toa Gosei Chemical Industry Co., Ltd .; “Aronix (registered trademark)” series, etc.), Nippon Oil and Fats Corporation; (trade name “Blemmer (registered trademark)” series, etc.), Nippon Kayaku Co., Ltd .; (trade name “KAYARAD (registered trademark)” series, etc.), Products such as Kyoeisha Chemical Co., Ltd. (trade names “light ester” series, “light acrylate” series, etc.) can be used.

In the present invention, various additives can be further blended in the hard coat layer as required, as long as the effects of the present invention are not impaired. For example, stabilizers such as antioxidants, light stabilizers, ultraviolet absorbers, surfactants, leveling agents, antistatic agents, and the like can be used.

¡Leveling agents are effective in reducing surface irregularities, especially when functional layers are applied. As the leveling agent, for example, a dimethylpolysiloxane-polyoxyalkylene copolymer (for example, SH190 manufactured by Toray Dow Corning Co., Ltd.) is suitable as the silicone leveling agent.

[Ultraviolet reflective layer]
The ultraviolet reflective layer installed in the film mirror 5 of the embodiment of the present invention is a layer that reflects ultraviolet light and transmits visible light and infrared light. The ultraviolet reflection layer preferably has an average reflectance of 75% or more for electromagnetic waves (ultraviolet rays) of 300 nm to 400 nm. The ultraviolet reflective layer preferably has an average transmittance of 80% or more for electromagnetic waves (visible light and infrared light) of 400 nm to 2500 nm.

In the film mirror according to the present invention, the polymer film layer is disposed on the side of the metal reflection layer on which sunlight is incident, and the sunlight that has passed through the polymer film layer is reflected by the metal reflection layer. Always exposed to sunlight. Therefore, by disposing the ultraviolet reflective layer on the side of the polymer film layer on which sunlight is incident, the polymer film layer can be prevented from being deteriorated and discolored by ultraviolet rays, and the decrease in light transmittance of the polymer film layer can be reduced. Therefore, it becomes possible to reduce the reflectance drop of the film mirror. Further, by providing the ultraviolet reflecting layer on the side of the polymer film layer on which sunlight is incident, it is possible to reduce a decrease in moisture resistance of the polymer film layer due to deterioration of the polymer film layer due to ultraviolet rays of sunlight. Therefore, it is possible to prevent the metal reflective layer from being deteriorated due to the deterioration of the moisture resistance of the polymer film layer, so that it is possible to reduce the reflectance drop of the film mirror.

Although the ultraviolet reflective layer is not particularly limited, a dielectric multilayer film of alternating layers of two or more kinds of dielectric materials having different refractive indexes can be used. The dielectric multilayer film according to the present invention is preferably configured by alternately stacking a high refractive index dielectric layer and a low refractive index dielectric layer in an amount of 2 to 6 layers alternately. Thus, the scratch resistance of a dielectric multilayer film can be improved by using a multilayer structure in which dielectric layers are stacked. The high refractive index dielectric layer preferably has a refractive index of 2.0 to 2.6. Further, the low refractive index dielectric layer preferably has a refractive index of 1.8 or less.

The dielectric layer of high refractive index can be preferably used _SiO 2, _Al 2 _{O 3} as a dielectric layer of _ZrO 2, TiO ₂ the low refractive index. As the high refractive index dielectric layer used in the present invention, TiO ₂ can be used, and as the low refractive index dielectric layer, SiO ₂ can be used more preferably. When TiO ₂ is used on the outermost surface of the ultraviolet reflection layer, that is, the outermost surface of the film mirror, as a dielectric material having a high refractive index, the anti-fouling effect on the mirror surface due to the photocatalytic effect of TiO ₂ can be obtained. It is possible to reduce the decrease in the reflectance of the film mirror caused by the above.

(Sacrificial protection layer)
The sacrificial anticorrosive layer installed on the film mirror 6 of the embodiment of the present invention is a layer that protects the metal reflective layer by sacrificial anticorrosion, and the sacrificial anticorrosive layer is disposed between the metal reflective layer and the protective layer. Thus, the corrosion resistance of the metal reflective layer can be improved. In the present invention, the anticorrosive sacrificial layer is preferably copper having a higher ionization tendency than silver, and the copper anticorrosive sacrificial layer is provided under the reflective layer made of silver, thereby suppressing the deterioration of silver.

The film mirror of the present invention can be manufactured by the following steps.

[Step 1]
A biaxially stretched polyester film (polyethylene terephthalate film, thickness 60 μm) is prepared as a base material for the polymer film, placed inside the vapor deposition machine, and the inside of the vapor deposition machine is evacuated by a vacuum pump. In the vacuum deposition machine, there are arranged a feeding device for feeding out a polymer film wound in a roll shape, and a winding device for taking up the polymer film deposited on the polymer film by vapor deposition. A large number of rolls are arranged between the feeding device and the winding device so as to respectively guide the film, and are driven to rotate in synchronization with the polymer film travel by the driving means.

[Step 2]
A metal oxide deposition nucleus evaporation source is disposed at a position facing the upstream portion of the polymer film traveling direction. The deposition nuclear evaporation source is for depositing metals such as Si, Al, Ag, Cu, etc. on polymer films. Metal vapor is generated by vacuum deposition or the like, and the metal is uniformly distributed over the entire width of the film. An oxide vapor deposition film and a metal vapor deposition film are formed.

[Step 3]
A polyester-based pressure sensitive adhesive is applied to the surface of the metal vapor deposition film produced in step 2 to a thickness of 5 μm. Not only the above-mentioned production order but also a corrosion inhibitor effective for preventing metal deterioration after step 2 may be applied, and a sacrificial anticorrosive layer, for example, Cu may also be deposited to prevent metal deterioration.

In addition, in order to protect the polymer film from strong ultraviolet rays, if an ultraviolet absorber is added to the polymer film and other hard coat layers arranged on the side where sunlight is incident, coloring is prevented and reflection efficiency is maintained. be able to.

(Sunlight collector mirror)
The film mirror of the present invention can be preferably used for the purpose of collecting sunlight. Although the film mirror can be used alone as a sunlight collecting mirror, more preferably, the film mirror is attached to a support via an adhesive layer and used as a sunlight collecting mirror.

(Support)
Examples of the support for the solar light collecting mirror of the present invention include a resin material or a metal material.

As the resin material, resin materials such as polycarbonate resin, polyacetal resin, acrylic resin, polystyrene resin, polyimide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, and ABS resin are used without particular limitation.

Also, examples of the metal material include an aluminum plate, an aluminum alloy plate, a brass plate, a stainless plate, and a steel plate.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples.

Example 1
(Preparation of film mirror sample 1)
As the polymer film, a biaxially stretched acrylic film (thickness: 60 μm) containing benzotriazole as an ultraviolet absorber was used. On one side of the acrylic film, a composite oxide starting from silicon oxide and aluminum oxide as a water vapor barrier layer having a metal oxide was deposited with a thickness of 80 nm. Vapor deposition materials of silicon oxide and aluminum oxide were formed by an electron beam vapor deposition method at a mixing ratio of 80:20. As a metal reflective layer, a 150 nm thick silver reflective layer is formed by vacuum deposition, and on the silver reflective layer, acrylic adhesive Sdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) is applied to a thickness of 5 μm as an adhesive. A release film was attached to obtain a sample 1 corresponding to the film mirror 1 of the embodiment of the present invention.

(Preparation of film mirror sample 2)
As the polymer film, a biaxially stretched polyester film (polyethylene terephthalate film, thickness 50 μm) containing an ultraviolet absorber benzotriazole was used. On one side of the polyethylene terephthalate film, a composite oxide starting from silicon and aluminum was deposited as a water vapor barrier layer having a metal oxide with a thickness of 300 nm. Vapor deposition materials of silicon oxide and aluminum oxide were formed by electron beam vapor deposition at a mixing ratio of 90:10.

As the metal reflective layer, a 150 nm thick silver reflective layer was formed by vacuum deposition, and an acrylic film was applied to the upper surface of the silver reflective layer to a thickness of 60 μm. The acrylic film contains the corrosion inhibitor dimercaptoacetate. Furthermore, acrylic adhesive Sdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) was applied in a thickness of 5 μm from above, and a release film was attached to obtain a sample 2 corresponding to the film mirror 2 of the embodiment of the present invention.

(Preparation of film mirror sample 3)
The polymer film 2 was a biaxially stretched polyester film (polyethylene terephthalate film, thickness 50 μm) as the polymer film. A 150 nm thick silver reflective layer was formed thereon as a metal reflective layer by vacuum deposition, and an acrylic film was applied to the upper surface of the silver reflective layer to a thickness of 60 μm. The acrylic film contains the corrosion inhibitor dimercaptoacetate. Acrylic pressure-sensitive adhesive Sdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) was applied to the surface opposite to the silver reflective layer as a pressure-sensitive adhesive to a thickness of 5 μm and a release film was attached. The sample prepared so far was designated as Sample A. In another process, a composite oxide starting from silicon and aluminum was deposited at a thickness of 300 nm as a water vapor barrier layer having a metal oxide on a polymer film 1 (thickness 25 μm) containing benzotriazole as an ultraviolet absorber. Vapor deposition materials of silicon oxide and aluminum oxide were formed by electron beam vapor deposition at a mixing ratio of 90:10. Sample B was a polymer film 1 with a water vapor barrier layer produced in this separate step. Sample A and Sample B were bonded via a polyester adhesive layer to obtain Sample 3 corresponding to Film Mirror 3 of the embodiment of the present invention.

(Preparation of film mirror sample 4)
The polymer film 1 was a biaxially stretched polyester film (polyethylene terephthalate film, thickness 12 μm) as the polymer film. A chemical vapor deposition (CVD) apparatus is used on one side of the polymer film 1 to form tetramethylenedisiloxane, oxygen, and helium at a ratio of 1:20:10 (slm) and a pressure of 100 × 10 ^−4. A thin film of silicon oxide (SiOx, X <2) was formed with a thickness of 60 nm as a water vapor barrier layer having a metal oxide under the conditions of Torr, vapor deposition rate 50 nm / S, and film thickness 10 nm. A 150 nm thick silver reflective layer was formed thereon as a metal reflective layer by vacuum deposition, and an acrylic film was applied to the upper surface of the silver reflective layer to a thickness of 60 μm. The acrylic film contains the corrosion inhibitor dimercaptoacetate. As an adhesive, acrylic adhesive Esdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) was applied to a thickness of 5 μm, and a release film was attached. 5% by mass of TINUVIN 328 (ultraviolet absorber, manufactured by BASF Japan) was mixed with methyl acrylate: butyl acrylate copolymer (ratio 64:36, ultraviolet curable resin) on the surface of the polymer film 1 having no silver reflection layer. The toluene solution is coated by a gravure coating method, dried at 80 ° C. for 30 seconds, and then irradiated with ultraviolet rays so that the accumulated light amount becomes 5000 mJ / cm ² to form an ultraviolet absorber-containing hard coat layer. Four samples corresponding to the film mirror 4 were obtained.

(Production of film mirror sample 5)
A sample 5 corresponding to the film mirror 5 of the embodiment of the present invention was obtained in the same manner as in Example 4 except that the ultraviolet reflecting layer was made of a metal oxide instead of the ultraviolet absorbent-containing hard coat layer. The ultraviolet reflection layer is composed of a dielectric multilayer film, and six layers of dielectric layers TiO ₂ (thickness 37 nm) having a high refractive index and dielectric layers SiO ₂ (thickness 65 nm) having a low refractive index are alternately formed by vacuum deposition. It is constructed by stacking. The total thickness of the ultraviolet reflecting layer is 306 nm.

(Preparation of film mirror sample 6)
As the polymer film, a biaxially stretched acrylic film (thickness 10 μm) containing benzotriazole as an ultraviolet absorber was used. An aluminum oxide layer having a thickness of 500 nm was deposited on one side of the acrylic film as a water vapor barrier layer having a metal oxide. The aluminum oxide vapor deposition material was formed by electron beam vapor deposition. As the metal reflection layer, a silver reflection layer having a thickness of 150 nm was formed by a vacuum deposition method, and a copper layer was deposited as a sacrificial anticorrosion layer by resistance heating to a thickness of 60 nm on the silver reflection layer. On the copper layer, an acrylic pressure-sensitive adhesive Sdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) was applied to a thickness of 5 μm as a pressure-sensitive adhesive, and a release film was attached to obtain a sample 6 corresponding to the film mirror 6 of the embodiment of the present invention. .

(Production of film mirror comparative sample 1)
A biaxially stretched polyester film (polyethylene terephthalate film, thickness 60 μm) was used as the polymer film. A 150 nm thick silver reflective layer is formed as a metal reflective layer on one side of the polyethylene terephthalate film by a vacuum deposition method, and a composite oxide starting from silicon and aluminum is deposited on the silver reflective layer to a thickness of 80 nm. did. A comparative sample 1 was obtained by applying an acrylic adhesive Sdyne # 7851 (manufactured by Sekisui Chemical Co., Ltd.) as a pressure-sensitive adhesive on the side opposite to the silver reflecting layer to a thickness of 5 μm and attaching a release film.

(Production of film mirror comparative sample 2)
Comparative sample 2 produced in the same process as sample 1 was obtained except that the process of forming the water vapor barrier layer having a metal oxide was not performed.

(Production of film mirror comparative sample 3)
Comparative sample prepared in the same process as Sample 1 except that the thickness of the polymer film was 10 μm, and a composite oxide using silicon oxide and aluminum oxide as a starting material was deposited at a thickness of 600 nm as a water vapor barrier layer having a metal oxide. 3 was obtained.

[Evaluation]
The following tests were performed on Samples 1 to 6 and Comparative Samples 1 to 3 produced as described above, and the results are shown in Table 1 below.

(Reflectance measurement)
Each film mirror sample obtained was cut into a 2.5 cm square of the measurement size, the reflectance measurement mode of the spectrophotometer U4000 (manufactured by Hitachi High-Technologies) was selected, and the reflection of the incident light at an angle of 5 ° Light was guided to an integrating sphere and the regular reflectance was measured. The wavelength range was 2500 nm to 250 nm, and it was confirmed whether there was any wavelength range in which the reflectance dropped. The reflectances in the infrared light region (2500 nm to 800 nm) and the visible light region (800 nm to 400 nm) were averaged to obtain regular reflection average values for the examples and comparative examples.

○: Regular reflectance average value is 90% or more △: Regular reflectance average value is 80% or more and less than 90% ×: Regular reflectance average value is less than 80% (Storage conditions)
Each of the obtained film mirror samples was wound around a core having a diameter of 6 cm and stored in an environment of 25 ° C. and 50% for 30 days. Deterioration tests 1 to 3 were conducted after storage.

Degradation test 1 (moisture resistance test)
The specular reflectance measurement described above was carried out after being left for 30 days in a constant temperature bath under conditions of a temperature of 85 ° C. and a humidity of 85% RH. The determination of regular reflectance is the same as described above.

Degradation test 2 (Ammonium sulfide test)
The test was conducted according to the method described in Appendix 2 of JIS-H8623 using ammonium sulfide specified in JIS-K8943. After being immersed in an aqueous ammonium sulfide solution and allowed to stand for 24 hours, the regular reflectance of the film mirror was measured. The determination of regular reflectance is the same as described above.

Degradation test 3 (acetate spray test)
The test was carried out according to the method described in JIS-Z2371: 2000 using 35 ° C., 5% sodium chloride and pH = 3 acetic acid specified in JIS-Z2371: 2000. The specular reflectance of the film mirror was measured after putting it into the test for 24 hours. The determination of regular reflectance is the same as described above.

As is clear from the results in Table 1, the samples 1 to 6 of the present invention were all good in the deterioration of reflectance as compared with the comparative samples 1 to 3. In Comparative Sample 1, it was found that fine cracks were generated in the metal oxide layer on the surface, the gas barrier property was lost, and the reflectance was lowered after the deterioration test.

Example 2
Using samples 1 to 6 of the present invention and comparative samples 1 to 3, solar light collecting mirrors were produced by the following method.

[Production of film mirrors for solar power generation]
An actual film mirror for solar thermal power generation has a length of at least 1 m on a side and cannot be evaluated with an evaluation measuring device with the size as it is. Therefore, a solar power generation reflective device with a small size as shown below is produced. The film mirror for solar power generation was evaluated using this.

The above-prepared samples 1 to 6 and comparative samples 1 to 3 are attached to a stainless steel (SUS304) plate having a thickness of 15.4 mm and a length of 25.4 mm × width of 76.2 mm through an adhesive layer having a thickness of 5 μm. A film mirror for solar thermal power generation was prepared.

The samples 1 to 6 of the present invention were exposed to the outdoors for 3 years, but the reflectivity of the metal reflective layer was 90% or more, and there was no problem. On the other hand, in Comparative Sample 2 without a water vapor barrier having a metal oxide, the metal reflective layer deteriorated after one year of outdoor exposure. Although Comparative Samples 1 and 3 had a metal oxide layer, the metal reflective layer deteriorated after two years of outdoor exposure due to a decrease in water vapor barrier properties due to the occurrence of cracks.

E film mirror 1 polymer film layer 2 gas barrier layer 3 reflective layer 4 adhesive layer 5 release film

Claims

A film mirror in which a polymer film layer, a gas barrier layer having a metal oxide, and a metal reflection layer are arranged in this order from the sunlight incident side, the thickness of the gas barrier layer with respect to the polymer film layer A film mirror having a function of reflecting sunlight, wherein the ratio is in the range of 0.1% to 5%.
2. The film mirror according to claim 1, wherein the polymer film layer has a thickness in the range of 10 μm to 125 μm.
The film mirror according to claim 1 or 2, wherein the metal oxide of the gas barrier layer is at least one selected from silicon oxide, aluminum oxide, and a mixture of two types of silicon oxide and aluminum oxide. .
The film mirror according to any one of claims 1 to 3, wherein the metal of the reflective layer is silver.
The film mirror according to any one of claims 1 to 4, wherein the metal reflective layer is formed by wet plating.
The film mirror according to any one of claims 1 to 4, wherein the metal reflective layer is formed by dry plating.
The film mirror according to any one of claims 1 to 6, wherein the polymer film layer contains an ultraviolet absorber.
In contact with the metal reflective layer, at least one selected from thioether, thiol, Ni organic compound, benzotriazole, imidazole, oxazole, tetrazaindene, pyrimidine, and thiadiazole The film mirror according to any one of claims 1 to 7, further comprising a corrosion inhibitor layer contained therein.
The film mirror according to any one of claims 1 to 8, wherein a Cu layer is provided in contact with the metal reflective layer.
The film mirror according to any one of claims 1 to 9, wherein the film mirror has an adhesive layer on the side opposite to the side on which sunlight is incident.
11. The film mirror manufacturing method according to claim 1, wherein the metal reflective layer is formed by silver vapor deposition.
A solar light collecting mirror, wherein the film mirror according to claim 10 is formed on a support through an adhesive layer of the film mirror.