WO2015079803A1

WO2015079803A1 - Film mirror

Info

Publication number: WO2015079803A1
Application number: PCT/JP2014/076593
Authority: WO
Inventors: 光範後藤
Original assignee: コニカミノルタ株式会社
Priority date: 2013-11-28
Filing date: 2014-10-03
Publication date: 2015-06-04
Also published as: JP2017026644A

Abstract

A film mirror is provided which can suppress and prevent increases in haze in a high-temperature environment. In order from the light incidence side, this film mirror comprises at least a transparent resin layer having a UV absorbent, a urethane-modified acrylic resin layer, and either a resin substrate and a light reflecting layer, or a light reflecting layer and a resin substrate.

Description

Film mirror

The present invention relates to a film mirror. More specifically, the present invention relates to a film mirror that can suppress an increase in haze under a high temperature environment. The film mirror of this invention can be used conveniently for the reflective apparatus for solar power generation.

In recent years, global warming has developed into a more serious situation. Its main cause is believed to be the atmospheric carbon dioxide released from fossil fuels it has been used in a large amount as an energy source in the 20th century (CO _2). Therefore, it is considered that it will not be allowed to continue using fossil fuels in the near future. On the other hand, the depletion of oil and natural gas, once thought to be inexhaustible, has become a reality due to the increase in energy demand accompanying the rapid economic growth of so-called developing countries such as China, India and Brazil. Yes.

Solar energy is considered to be the most stable and abundant amount of natural energy as an alternative energy to fossil fuels. In particular, the vast desert spreads near the equator, which is called the world's sun belt, and the solar energy that falls there is truly inexhaustible. With regard to the use of solar energy, it is thought that 7,000 GW of energy can be obtained if only a few percent of the desert that extends to the southwestern United States is used. It is also believed that using only a few percent of the Arabian peninsula and the deserts of North Africa can cover all the energy used by all mankind.

Thus, although solar energy is a very powerful alternative energy, in order to utilize it in social activities, (1) the energy density of solar energy is low, and (2) solar energy storage. And the difficulty of transport is considered a problem. On the other hand, it has been proposed to solve the problem that the energy density of solar energy is low by collecting solar energy with a huge concentrator.

Since the condensing device is exposed to sunlight, ultraviolet rays, heat, wind and rain, sandstorms, etc., conventionally, a glass mirror having good weather resistance has been used. However, the glass mirror has high environmental durability, but it is damaged during transportation, and because of its heavy mass, it is necessary to increase the strength of the frame on which the mirror is installed, which increases the construction cost of the plant. There was a problem.

In order to solve the above problem, it has been considered to replace the glass mirror with a resin reflecting mirror.

However, when a metal such as silver is used for the reflection layer of the resin reflection mirror, oxygen, water vapor, hydrogen sulfide, etc. are transmitted through the resin layer, and silver is corroded. Since it deteriorates and causes problems such as discoloration and film peeling, it is difficult to apply a resin reflection mirror to the light collecting device.

With respect to the problem of such a resin reflecting mirror, a technique is known in which an acrylic film having excellent light resistance to ultraviolet rays is used on the surface by separating the upper side of the silver layer from contact with the adhesive (for example, Patent Document 1).

Special table 2009-520174 (corresponding to WO 2007/076282)

However, the silver mirror structure described in Patent Document 1 has a problem that haze increases under a high temperature environment.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a film mirror capable of suppressing and preventing an increase in haze under a high temperature environment.

Another object of the present invention is to provide a film mirror that can suppress / prevent a decrease in reflectance under a high temperature environment.

As a result of intensive studies to solve the above problems, the present inventor has arranged a urethane-modified acrylic resin layer between a translucent resin layer containing an ultraviolet absorber and a resin substrate or a light reflecting layer. Thus, the inventors have found that the above-mentioned problems can be solved and completed the present invention.

That is, the above-mentioned objects are, in order from the light incident side, a light-transmitting resin layer containing an ultraviolet absorber, a urethane-modified acrylic resin layer, and a resin base material and a light reflecting layer, or an ultraviolet absorber in order from the light incident side. Can be achieved by a film mirror having at least a translucent resin layer containing urethane, a urethane-modified acrylic resin layer, and a light reflecting layer and a resin base material.

It is a schematic sectional drawing which shows one Embodiment of the structure of the film mirror of this invention. In FIG. 1A, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 6 is an adhesive layer; and 10 is a film mirror. Show. It is a schematic sectional drawing which shows one Embodiment of the structure of the solar power generation reflective apparatus which concerns on this invention. In FIG. 1B, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 6 is an adhesive layer; 7 is a supporting substrate; Reference numeral 20 denotes a solar power generation reflecting device. It is a schematic sectional drawing which shows other embodiment of the structure of the film mirror of this invention. In FIG. 2A, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 6 is an adhesive layer; and 10 is a film mirror. Show. It is a schematic sectional drawing which shows other embodiment of the structure of the solar power generation reflective apparatus which concerns on this invention. In FIG. 2B, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 6 is an adhesive layer; 7 is a supporting substrate; Indicates solar power generation reflectors, respectively. It is a schematic sectional drawing which shows other embodiment of the structure of the film mirror of this invention. In FIG. 3A, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 5 is a hard coat layer; 6 is an adhesive layer; Reference numeral 10 denotes a film mirror. It is a schematic sectional drawing which shows other embodiment of the structure of the solar power generation reflective apparatus which concerns on this invention. In FIG. 3B, 1 is a light reflecting layer; 2 is a resin substrate; 3 is a urethane-modified acrylic resin layer; 4 is a translucent resin layer; 5 is a hard coat layer; 6 is an adhesive layer; Reference numeral 20 denotes a supporting substrate; and 20 denotes a reflector for solar power generation.

The present invention includes (i) a light-transmitting resin layer containing an ultraviolet absorber (hereinafter also simply referred to as “light-transmitting resin layer”), a urethane-modified acrylic resin layer, a resin base material, and light, in order from the light incident side. The present invention relates to a reflective layer, or (ii) a film mirror having at least a light-transmitting resin layer containing a UV absorber, a urethane-modified acrylic resin layer, and a light reflecting layer and a resin base material in this order from the light incident side. The present invention is characterized in that a urethane-modified acrylic resin layer is disposed between a translucent resin layer containing an ultraviolet absorber and (i) a resin substrate or (ii) a light reflecting layer. With this configuration, the film mirror of the present invention can suppress / prevent an increase in haze under a high temperature environment. More specifically, with this configuration, an increase in haze under a high temperature environment and a decrease in reflectance can be suppressed / prevented. Here, the mechanism for exerting the above-described effects by the configuration of the present invention is presumed as follows. The present invention is not limited to the following mechanism.

That is, as disclosed in Patent Document 1, a UV shielding acrylic film (translucent resin layer containing an ultraviolet absorber) is placed on a polymer film (resin base material) disposed on a silver overlay (light reflecting layer). The silver mirror structure (film mirror) configured to be disposed in the structure can reduce the number of layers / interfaces on the light reflection layer and suppress the reduction in reflectance, as compared with the conventional resin film bonding type. On the other hand, film mirrors are often used for solar power generation reflectors in vast deserts where solar energy falls infinitely. For this reason, the film mirror needs to exhibit and maintain a high reflectance and a low haze even in a high temperature environment. However, in the film mirror described in Patent Document 1, under such a high temperature environment, the ultraviolet absorber contained in the UV shielding acrylic film bleeds out and causes whitening of the polymer film or the like. For this reason, when exposed to a high temperature environment, the haze of a film mirror will rise and the reflectance of a film mirror will fall gradually.

On the other hand, in the present invention, the urethane-modified acrylic resin layer efficiently traps the ultraviolet absorber bleed out from the translucent resin layer in a high temperature environment. For this reason, according to the film mirror of this invention, since whitening can be suppressed, a high reflectance can be exhibited, and also a high reflectance can be maintained by suppressing / preventing a decrease in reflectance even in a high temperature environment. The urethane-modified acrylic resin layer is excellent in adhesion (integration) with the translucent resin layer. For this reason, according to the film mirror of this invention, the raise of the haze in a high temperature environment can be suppressed / prevented effectively. In particular, when a hard coat layer is further provided on the translucent resin layer, bleed-out (whitening) from the translucent resin layer is more effectively suppressed, and a reduction in reflectance under a high temperature environment is more effective. It is possible to prevent.

Therefore, the film mirror of the present invention can effectively suppress and prevent the increase in haze and the decrease in reflectivity under high temperature environment. In addition, the said effect becomes remarkable when it exposes to a high temperature environment especially for a long period (for example, 40 days or more, Preferably about 20 years). For this reason, the film mirror of this invention can be used conveniently for the solar power generation reflective apparatus.

Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited only to the following embodiment. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

In this specification, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

[Film mirror]
The film mirror of this invention has (a) the translucent resin layer containing a ultraviolet absorber, the urethane-modified acrylic resin layer, the resin base material, and the light reflection layer in order from the light incident side, as shown in FIG. Or (b) As shown in FIG. 2, in order from the light incident side, it has a translucent resin layer containing a UV absorber, a urethane-modified acrylic resin layer, a light reflecting layer, and a resin base material.

Specifically, FIG. 1A is a schematic cross-sectional view showing an embodiment of the configuration of the film mirror of the present invention. As shown in FIG. 1A, the film mirror 10 of the form (a) includes, in order from the light incident side, a translucent resin layer 4, a urethane-modified acrylic resin layer 3, a resin base material (for example, a resin film) 2, And at least a light reflection layer (for example, a silver reflection layer) 1. In addition to the above, the film mirror 10 may have an adhesive layer 6 on the side where the resin base material 2 of the light reflecting layer 1 is not disposed. In addition, another layer may be interposed between each of the above-mentioned layers, and each layer may be adjacent. According to the said form, since it is excellent in the adhesiveness of the urethane-modified acrylic resin layer 3 and the resin base material 2 (for example, polyester base materials, such as PET), the haze fall under a high temperature environment can be suppressed / prevented more effectively. .

In the film mirror 10 of FIG. 1A, the resin base material 2 is disposed on the light incident side with respect to the light reflection layer 1, but the present invention is not limited to this form, and the light reflection layer 1 is formed on the resin base material 2. On the other hand, it may be arranged on the light incident side (form (b) above). That is, FIG. 2A is a schematic sectional view showing another embodiment of the configuration of the film mirror of the present invention. As shown in FIG. 2A, the film mirror 10 according to the embodiment (b) includes a light-transmitting resin layer 4, a urethane-modified acrylic resin layer 3, and a light reflection layer (for example, a silver reflection layer) 1 in order from the light incident side. And a resin base material (for example, resin film) 2 at least. In addition to the above, the film mirror 10 may have an adhesive layer 6 on the side of the resin substrate 2 on which the light reflecting layer 1 is not disposed. In addition, another layer may be interposed between each of the above-mentioned layers, and each layer may be adjacent. According to the said form, since the light reflection layer 1 does not contact | connect the adhesion layer 6, a contaminant invades from the interface of the adhesion layer 6 and the light reflection layer 1, the light reflection layer 1 corrodes, and a reflectance falls. Can be suppressed / prevented. Moreover, since the resin base material 2 is provided between the pressure-sensitive adhesive layer 6 and the light reflecting layer 1, the unevenness of the pressure-sensitive adhesive layer 6 is not reflected on the light reflecting layer 1, and the light reflecting layer 1 with high flatness is obtained. And a higher reflectance can be achieved.

Here, the translucent resin layer 4 is laminated with the resin base material 2 (form (a); FIG. 1A) or the light reflection layer 1 (form (b); FIG. 2A) through the urethane-modified acrylic resin layer 3. Is done. Conventionally, under a high temperature environment, the ultraviolet absorber bleeds out from the translucent resin layer 4 to induce whitening, thereby causing a decrease in the reflectance of the film mirror. On the other hand, according to the present invention, the urethane-modified acrylic resin layer 3 efficiently traps the ultraviolet absorber that bleeds out from the translucent resin layer 4 in a high-temperature environment. Whitening can be effectively suppressed / prevented. Therefore, the film mirror of the present invention can exhibit a high reflectivity, and can maintain and maintain a high reflectivity by suppressing / preventing a decrease in reflectivity even under a high temperature environment. In addition, since the urethane-modified acrylic resin layer 3 is excellent in adhesiveness with the translucent resin layer 4, the haze is hardly increased or does not increase even in a high temperature environment.

In the film mirror of the present invention, the urethane-modified acrylic resin layer 3 and the translucent resin layer 4 can be formed by coating. For this reason, it is not necessary to attach a translucent resin film by melt film formation, and the problem of scattering of reflected light due to surface irregularities caused by melt film formation can be prevented. Therefore, the film mirror of the present invention can achieve a high reflectance. In addition, when the urethane-modified acrylic resin layer 3 and the translucent resin layer 4 are bonded together, there is a possibility that air bubbles and foreign substances are not mixed between the layers and the light reflectivity is lowered.

The film mirror of the present invention may have any configuration as long as it has at least the above members. Specifically, as shown in FIG. 3A, a hard coat layer 5 may be provided on the light incident side surface of the translucent resin layer 4. That is, the film mirror preferably further includes a hard coat layer on the light incident side surface of the translucent resin layer. With this configuration, it is possible to effectively suppress or prevent the film mirror surface from being damaged or contaminated. Moreover, it can also prevent that the ultraviolet absorber in a translucent resin layer comes out on the surface, and causes a raise of a haze. For this reason, even if a film mirror is used for a solar power generation reflection device and exposed to sunlight, ultraviolet rays, heat, wind and rain, sandstorms, etc. for a long time, the high reflectivity of the film mirror can be exhibited and maintained more effectively. In FIG. 3A, the hard coat layer is disposed on the translucent resin layer of the film mirror according to the form of FIG. 1A. However, the present invention is not limited to the above form, for example, according to the form of FIG. 2A. A form in which the hard coat layer is disposed on the translucent resin layer of the film mirror is also preferable. In addition to the above configuration, a corrosion prevention layer is disposed between the light reflecting layer 1 and the adhesive layer 6; an anchor layer is disposed between the light reflecting layer 1 and the resin substrate 2; A configuration such as a combination can be applied.

The thickness of the entire film mirror of the present invention is not particularly limited, but is preferably 20 to 300 μm, more preferably 30 to 200 μm, and still more preferably 50 to 170 μm from the viewpoints of prevention of bending, regular reflectance, and handling properties. . In addition, it is preferable that the center line average roughness (Ra) of the outermost surface layer on the light incident side of the film mirror is 3 nm or more and 20 nm or less from the viewpoint of preventing scattering of reflected light and increasing the light collection efficiency.

Here, an example of a preferable layer configuration of a film mirror for solar power generation will be described with reference to FIGS. 1A to 3A. An outline of the solar power generation reflecting device is shown in FIGS. 1B to 3B.

A film mirror 10 shown in FIG. 1A is provided by laminating a resin base material 2, a urethane-modified acrylic resin layer 3, and a translucent resin layer 4 on a light reflecting layer 1 in this order. An adhesive layer 6 is provided on the opposite surface of the light reflecting layer 1 to the light incident side. As shown in FIG. 1B, the solar power generation reflection device 20 using the film mirror joins the adhesive layer 6 in the film mirror 10 to the support substrate 9, and bonds the film mirror 10 and the support substrate 9 together. It is a reflecting mirror.

The film mirror 10 shown in FIG. 2A is provided by laminating a light reflecting layer 1, a urethane-modified acrylic resin layer 3, and a translucent resin layer 4 in this order on a resin substrate 2. An adhesive layer 6 is provided on the opposite surface of the resin substrate 2 on the light incident side. As shown in FIG. 2B, the solar power generation reflecting device 20 using the film mirror joins the adhesive layer 6 in the film mirror 10 to the support substrate 9, and bonds the film mirror 10 and the support substrate 9 together. It is a reflecting mirror.

The film mirror 10 shown in FIG. 3A is provided by laminating a resin base material 2, a urethane-modified acrylic resin layer 3, a translucent resin layer 4, and a hard coat layer 5 in this order on a light reflecting layer 1. An adhesive layer 6 is provided on the opposite surface of the light reflecting layer 1 to the light incident side. As shown in FIG. 3B, the solar power generation reflection device 20 using the film mirror joins the adhesive layer 6 in the film mirror 10 to the support substrate 9, and bonds the film mirror 10 and the support substrate 9 together. It is a reflecting mirror.

The details of each component layer are described below.

(Translucent resin layer)
The translucent resin layer is a resin layer made of a resin material having optical transparency and containing an ultraviolet absorber.

The resin material used for the translucent resin layer is not particularly limited, and various conventionally known synthetic resins that can maintain transparency when a thin film is formed can be used. For example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, and cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate (CAP), cellulose Cellulose esters such as acetate phthalate and cellulose nitrate or their derivatives, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether sulfone (PES), polysulfones, polyether ketone imide, polyamide, fluorine Fat, nylon, polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), (meth) acrylic materials such as poly (meth) acrylate, acrylic or polyarylates, Arton (trade name manufactured by JSR) or Appel (product) And a cycloolefin resin such as “Mitsui Chemicals”.

The method for forming the translucent resin layer is not particularly limited, and examples thereof include a method by coating. When a coating film that becomes a translucent resin layer is applied by a coating method, various conventionally used coating methods such as spray coating, spin coating, and bar coating can be used. That is, the translucent resin layer can be formed by directly applying the material constituting the translucent resin layer on the light incident side surface of the urethane-modified acrylic resin layer.

By forming the translucent resin layer by such a coating method, the smoothness of the translucent resin layer can be improved. Specifically, the center line average roughness (Ra) of the translucent resin layer formed by the coating method can be 3 nm or more and 20 nm or less. In other words, if the center line average roughness satisfies this value, the translucent resin film produced by melt film formation is not a translucent resin layer provided by bonding with an adhesive layer, but the translucent resin film. It can be considered that the conductive resin layer is provided by coating. The center line average roughness (Ra), which is an index of smoothness of the translucent resin layer, can be determined by a measuring method based on JIS B0601-1982.

The thickness (dry film thickness) of the translucent resin layer is not particularly limited, but is preferably 5 to 150 μm, more preferably 10 to 100 μm, and particularly preferably 20 to 80 μm. With such a thickness, sufficient translucency is secured, and the solvent can be sufficiently evaporated by drying during film formation, which is preferable in terms of productivity.

Among the resin materials exemplified above, a (meth) acrylic material is preferably used as the material for forming the light-transmitting resin layer. When the translucent resin layer is formed of a (meth) acrylic material, since the (meth) acrylic material is hard, the plasticizer fine particles are added for the purpose of obtaining an acrylic translucent resin layer that is soft and difficult to break. You may make it contain. Preferable examples of the plasticizer include acrylic rubber, butyl rubber and butyl acrylate. Here, the amount of the plasticizer to be added is not particularly limited, but in consideration of desired flexibility, it is about 10 to 25% by mass with respect to the resin (translucent resin) (in terms of solid content). preferable.

More preferably, the translucent resin layer is formed with a methacrylic resin as a main component. The methacrylic resin is a polymer mainly composed of a methacrylic acid ester, and may be a homopolymer of a methacrylic acid ester. The methacrylic acid ester is 50% by mass or more and the other monomer is 50% by mass or less. A copolymer may also be used. Here, as the methacrylic acid ester, an alkyl ester of methacrylic acid is usually used. A particularly preferred methacrylic resin is polymethyl methacrylate resin (PMMA).

The preferred monomer composition of the methacrylic resin is 50 to 100% by weight of methacrylic acid ester, 0 to 50% by weight of acrylic acid ester, and 0 to 49% by weight of other monomers based on the total monomers. More preferably, methacrylic acid ester is 50 to 99.9% by mass, acrylic acid ester is 0.1 to 50% by mass, and other monomers are 0 to 49% by mass.

Here, examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like, and the alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. It is. Of these, methyl methacrylate is preferably used.

Examples of alkyl acrylates include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. The alkyl group usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. is there.

The monomer other than alkyl methacrylate and alkyl acrylate may be a monofunctional monomer, that is, a compound having one polymerizable carbon-carbon double bond in the molecule, or a polyfunctional monofunctional monomer. Although it may be a monomer, that is, a compound having at least two polymerizable carbon-carbon double bonds in the molecule, a monofunctional monomer is preferably used. Examples of the monofunctional monomer include aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyl toluene, and alkenyl cyan compounds such as acrylonitrile and methacrylonitrile. Examples of polyfunctional monomers include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate, allyl acrylate, allyl methacrylate, and cinnamon. Alkenyl esters of unsaturated carboxylic acids such as allyl acids, polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, aromatic polyalkenyl compounds such as divinylbenzene, etc. Can be mentioned.

In addition, as for said alkyl methacrylate, alkyl acrylate, and monomers other than these, respectively, you may use those 2 or more types as needed.

The glass transition temperature of the methacrylic resin is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of heat resistance of the film. This glass transition temperature can be appropriately set by adjusting the type of monomer and the ratio thereof.

The methacrylic resin can be prepared by polymerizing the monomer component by a method such as suspension polymerization, emulsion polymerization or bulk polymerization. At that time, in order to obtain a suitable glass transition temperature or to obtain a viscosity showing a formability to a suitable film, it is preferable to use a chain transfer agent during the polymerization. The amount of the chain transfer agent may be appropriately determined according to the type of monomer and the ratio thereof.

Alternatively, a commercially available product may be used as the resin material used for the translucent resin layer such as methacrylic resin.

Although there is no restriction | limiting in particular in the ultraviolet absorber contained in a translucent resin layer, For example, organic, such as a thiazolidone type, a benzotriazole type, an acrylonitrile type, a benzophenone type, an aminobutadiene type, a triazine type, a phenyl salicylate, a benzoate type Type ultraviolet absorbers, fine powder type ultraviolet blocking agents such as cerium oxide and magnesium oxide, titanium oxide, zinc oxide, iron oxide and the like, and organic ultraviolet absorbers are particularly preferable.

As organic ultraviolet absorbers, for example, JP-A-46-3335, JP-A-55-152776, JP-A-5-197004, JP-A-5-232630, JP-A-5-307232, JP-A-6-2111813, -53427, 8-234364, 8-239368, 9-310667, 10-115898, 10-147777, 10-182621, German Patent No. 19739797A, Europe Japanese Patent No. 711804A and Japanese Patent Publication No. 8-501291, US Patent No. 1,023,859, No. 2,685,512, No. 2,739,888, No. 2,784, No. 087, No. 2,748,021, No. 3,004,896, No. 3,052,636, No. 3,215,530, No. 3,253, No. 21, No. 3,533,794, No. 3,692,525, No. 3,705,805, No. 3,707,375, No. 3,738,837, No. The compounds described in 3,754,919, British Patent 1,321,355 and the like can be used.

Specific examples of the benzophenone ultraviolet absorber include 2,4-dihydroxy-benzophenone, 2-hydroxy-4-methoxy-benzophenone, 2-hydroxy-4-n-octoxy-benzophenone, 2-hydroxy-4-dodecyloxy. -Benzophenone, 2-hydroxy-4-octadecyloxy-benzophenone, 2,2'-dihydroxy-4-methoxy-benzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-benzophenone, 2,2 ', 4 4,4′-tetrahydroxy-benzophenone and the like.

Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, 2 -(2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1, 3,3-tetramethylbutyl) phenol] (molecular weight 659; examples of commercial products are LA31 from ADEKA Corporation), 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl- 1-phenylethyl) phenol (molecular weight 447.6; examples of commercially available products are TINUVIN 234 manufactured by BASF), 2- (2H-benzotriazole 2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol (TINUVIN928, trade name, manufactured by BASF), and the like.

Examples of the phenyl salicylate ultraviolet absorber include phenylsalicylate, 2-4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, and the like. Examples of the hindered amine ultraviolet absorber include bis (2,2,6,6-tetramethylpiperidin-4-yl) sebacate.

Examples of triazine ultraviolet absorbers include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-). Ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-) Butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2- Hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-tria 2,4-diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-benzyloxyphenyl)- 1,3,5-triazine, [2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol] (TINUVIN1577FF, trade name, manufactured by BASF), TINUVIN479 (Trade name, manufactured by BASF) and the like, [2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) ) Phenol] (CYASORB UV-1164, trade name, manufactured by Cytec Industries).

Examples of benzoate UV absorbers include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate (molecular weight 438.7; Sumisorb 400).

Among these UV absorbers, UV absorbers having a molecular weight of 400 or more are less likely to volatilize at a high boiling point and are difficult to disperse even during high temperature molding, so that the weather resistance can be effectively improved with a relatively small amount of addition. it can.

In addition, since the ultraviolet absorber having a molecular weight of 400 or more has little transferability from the thin translucent resin layer 4 to other constituent layers and hardly deposits on the surface of the laminate, the amount of the ultraviolet absorber contained is small. It is preferable from the viewpoints of being maintained for a long time and being excellent in the durability of the weather resistance improving effect.

Examples of the ultraviolet absorber having a molecular weight of 400 or more include 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole, 2,2-methylenebis [4- (1, 1,3,3-tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl)- Benzotriazoles such as 4- (1,1,3,3-tetramethylbutyl) phenol, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6) , 6-pentamethyl-4-piperidyl) sebacate and other hindered amines, and 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1 , 2,2,6,6-pentamethyl-4-piperidyl), 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine and the like of a hybrid system having both hindered phenol and hindered amine structures in the molecule These can be used, and these can be used alone or in combination of two or more. Among these, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole, 2- (2H-benzotriazol-2-yl) -6- (1 -Methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2,2-methylenebis [4- (1,1,3,3-tetrabutyl) -6- (2H -Benzotriazol-2-yl) phenol] is particularly preferred.

In addition to the above, as the ultraviolet absorber, a compound having a function of converting the energy held by ultraviolet rays into vibrational energy in the molecule and releasing the vibrational energy as heat energy or the like can be used. Furthermore, those that exhibit an effect when used in combination with an antioxidant or a colorant, or light stabilizers acting as a light energy conversion agent, called quenchers, can be used in combination. However, when using the above-mentioned ultraviolet absorber, it is necessary to select one in which the light absorption wavelength of the ultraviolet absorber does not overlap with the effective wavelength of the photopolymerization initiator. When a normal ultraviolet absorber is used, it is effective to use a photopolymerization initiator that generates radicals with visible light.

In addition, each of the above ultraviolet absorbers may be used in combination of two or more thereof as necessary. Further, if necessary, an ultraviolet absorber other than the above-described ultraviolet absorber, for example, a salicylic acid derivative, a substituted acrylonitrile, a nickel complex, or the like can be contained.

The content (in terms of solid content) of the ultraviolet absorber in the translucent resin layer is not particularly limited, but is preferably from 0.1 to 25% by mass, more preferably based on the translucent resin layer. 0.5 to 20% by mass, more preferably 1 to 15% by mass. Further, the content (content per unit area of the film) of the ultraviolet absorber in the translucent resin layer is not particularly limited, but preferably 0.17 to 2.28 g / m ² , more preferably 0.4. To 2.28 g / m ² . By making the content of the UV absorber in the above range, it is more effective to cause rolls and films to become dirty due to bleeding out of the UV absorber (and hence haze increase) while exhibiting sufficient weather resistance. Can be suppressed / prevented.

The translucent resin layer may further contain an antioxidant in order to prevent deterioration. Although it does not restrict | limit especially as antioxidant, It is preferable to use a phenolic antioxidant, a thiol antioxidant, and a phosphite antioxidant. Here, as the phenol-based antioxidant, the thiol-based antioxidant, and the phosphite-based antioxidant, known antioxidants described in WO 2012/165460 and the like can be used, respectively.

(Urethane-modified acrylic resin layer)
The urethane-modified acrylic resin layer is provided on the surface opposite to the light incident side of the translucent resin layer.

The urethane-modified acrylic resin used for the urethane-modified acrylic resin layer is not particularly limited, but the following general formula (I):

It is preferable that it is shown by. The urethane-modified acrylic resin layer formed using such a urethane-modified acrylic resin traps UV absorbers (UV absorbers) that bleed out from the translucent resin layer in a high-temperature environment more effectively, Adhesion with the translucent resin layer is also higher. Therefore, by using a film mirror having a urethane-modified acrylic resin layer formed using such a urethane-modified acrylic resin, even when it is exposed to a high temperature environment for a long time, the haze increase and reflectance Can be suppressed and prevented more effectively.

In the general formula (I), R and R ′ represent an alkylene group. Here, R and R ′ may be the same or different. When p is 2 or more, each unit (—O—C (═O) —NH—R—NH—C (═O) —O—R′—) (unit (c)) is May be the same or different. Specific examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a propylene group. Of these, an alkylene group having 1 to 10 carbon atoms is preferable, and an alkylene group having 1 to 5 carbon atoms is more preferable.

M is the following formula:

The degree of polymerization of the unit (a) (acrylic unit) represented by the formula: is an integer of 10 to 500, preferably an integer of 50 to 300. n is the following formula:

The degree of polymerization of the unit (b) represented by the formula is an integer of 10 to 500, preferably an integer of 50 to 300. p is the number of units (c) (—O—C (═O) —NH—R—NH—C (═O) —O—R′—; urethane unit) present in the unit (b). Yes, an integer of 10 to 200, preferably an integer of 50 to 150. When a plurality of units (b) are present, each unit (b) may be the same or different.

In addition, the composition of the units (a) and (b) in the urethane-modified acrylic resin having the units (a) and (b) is not particularly limited, but the trapping property of the ultraviolet absorber that bleeds out from the translucent resin layer. From the viewpoint of adhesion to the translucent resin layer, the urethane / acrylic ratio (unit (b) / unit (a) molar ratio) is preferably 5/95 to 50/50, more preferably 10 / 90 to 30/70, more preferably 15/85 to 25/75. The units (a) and (b) may be block-shaped or random.

The weight average molecular weight of the urethane-modified acrylic resin is not particularly limited, but is preferably 10,000 from the viewpoint of the trapping property of the ultraviolet absorber that bleeds out from the translucent resin layer, the adhesion with the translucent resin layer, and the like. To 100,000, more preferably 20,000 to 50,000. In the present specification, “weight average molecular weight” is a value measured by gel permeation chromatography (Gel Permeation Chromatography, GPC) using polystyrene as a standard substance.

The hydroxyl value of the urethane-modified acrylic resin constituting the translucent resin layer is also not particularly limited, but the ultraviolet absorber that bleeds out from the translucent resin layer, the adhesiveness with the translucent resin layer, etc. From the viewpoint, it is preferably 15 to 40, more preferably 25 to 35. In the present specification, the “hydroxyl value of urethane-modified acrylic resin” is a value measured under the following conditions / method. It is expressed in mg of potassium hydroxide required to acetylate the hydroxyl group contained in 1 g of urethane-modified acrylic resin and neutralize acetic acid required for acetylation. For this reason, the hydroxyl value of urethane-modified acrylic resin can be controlled based on the carboxyl group and the amount of hydroxyl groups contained in the monomer to be blended.

The urethane-modified acrylic resin may be produced by polymerization using an appropriate monomer, or a commercially available product may be used. In the latter case, for example, ACRYT 8UA series (urethane-modified acrylic polymer) manufactured by Taisei Fine Chemical Co., Ltd. is used.

Although the formation method in particular of a urethane-modified acrylic resin layer is not restrict | limited, For example, the method by application | coating can be mentioned. When coating a coating film to be a urethane-modified acrylic resin layer by a coating method, various conventionally used coating methods such as spray coating, spin coating, bar coating, and gravure coating can be used. . That is, the urethane-modified acrylic resin layer is formed by directly applying the urethane-modified acrylic resin on the light incident side surface of the resin substrate or the light reflecting layer or another layer formed on the resin substrate or the light reflecting layer. Can be formed.

The thickness (dry film thickness) of the urethane-modified acrylic resin layer is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, still more preferably 0.1 to 2 μm, particularly preferably 0.5 to 1.5 μm. If the thickness of the urethane-modified acrylic resin layer is too thin, the effect of reducing bleed out is reduced, and the increase in haze over time is increased. If the thickness is too thick, the effect of reducing bleed out is obtained, but the resin over time Is greatly deformed, leading to a decrease in reflectance. Therefore, if it is the above thickness, the ultraviolet absorber bleed out from the translucent resin layer can be efficiently trapped, and sufficient adhesion with the translucent resin layer can be secured.

(Resin base material)
Various conventionally known resin films can be used as the resin base material. For example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate (PET), polyester film such as polyethylene naphthalate, polyethylene film, polypropylene film Cellophane, cellulose diacetate film, cellulose triacetate film, cellulose acetate propionate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene Resin film, polymethyl Down Ten films, polyether ketone films, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, and acrylic films. Among these, polycarbonate films, polyester films such as polyethylene terephthalate, norbornene resin films, cellulose ester films, and acrylic films are preferable. Of these, a polyester film such as polyethylene terephthalate or an acrylic film is preferably used, and a polyester film such as polyethylene terephthalate is particularly preferable. Here, the resin base material may be manufactured by any method, and may be, for example, a film manufactured by melt casting film formation or a film manufactured by solution casting film formation. .

Since the resin substrate is located farther from the light incident side than the light reflecting layer, it is difficult for ultraviolet rays to reach the resin substrate. In particular, when an ultraviolet absorber is contained in a translucent resin layer or the like that is closer to the light incident side than the resin base material, the ultraviolet rays are more difficult to reach the resin base material. Therefore, the resin base material can be used even if it is a resin that easily deteriorates with respect to ultraviolet rays. From such a viewpoint, a polyester film such as polyethylene terephthalate can be used as the resin base material.

The thickness of the resin substrate is not particularly limited, but is preferably an appropriate thickness depending on the type and purpose of the resin. The thickness of the resin substrate is preferably in the range of 10 to 250 μm, for example, and more preferably 20 to 200 μm.

(Light reflection layer)
The light reflecting layer is a layer made of metal or the like having a function of reflecting sunlight.

The surface reflectance of the light reflecting layer is preferably 80% or more, more preferably 90% or more. This light reflecting layer is preferably formed of a material containing any element selected from the group consisting of Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt and Au. Among these, it is preferable that Al or Ag is a main component from the viewpoint of reflectance and corrosion resistance, and two or more such metal thin films may be formed. In the present invention, a light reflecting layer mainly composed of silver is used.

The thickness of the light reflecting layer is preferably 10 to 200 nm, more preferably 30 to 150 nm, from the viewpoint of reflectivity and the like.

Moreover, a layer made of a metal oxide such as SiO ₂ or TiO ₂ may be provided on the light reflecting layer to further improve the reflectance.

As a method for forming this light reflecting layer, either a wet method or a dry method can be used. The wet method is a general term for a plating method, and is a method of forming a film by depositing a metal from a solution. Specific examples include silver mirror reaction. On the other hand, the dry method is a general term for a vacuum film-forming method. Specific examples include a resistance heating vacuum deposition method, an electron beam heating vacuum deposition method, an ion plating method, and an ion beam assisted vacuum deposition method. And sputtering method. In particular, a vapor deposition method capable of a roll-to-roll method for continuously forming a film is preferably used in the present invention. For example, in the manufacturing method of the film mirror for solar power generation, it is preferable that it is a manufacturing method which forms a light reflection layer by silver vapor deposition (especially vacuum vapor deposition).

(Adhesive layer)
The adhesive layer has adhesiveness that enables the film mirror to be attached to the support substrate, and the adhesive layer is used to join the film mirror to the support substrate to form a solar power generation reflection device. It is a constituent layer.

The adhesive layer is not particularly limited, and for example, any of a dry laminating agent, a wet laminating agent, an adhesive, a heat seal agent, a hot melt agent and the like can be used. As the adhesive, for example, a polyester resin, a urethane resin, a polyvinyl acetate resin, an acrylic resin, a nitrile rubber, or the like is used. The laminating method is not particularly limited, and for example, it is preferable to carry out the roll method continuously from the viewpoint of economy and productivity. The thickness of the pressure-sensitive adhesive layer is usually preferably in the range of about 1 to 100 μm from the viewpoints of the pressure-sensitive adhesive effect, the drying speed, and the like.

The film mirror may include a release sheet (not shown) that covers the surface of the adhesive layer on the side opposite to the resin substrate. When a film mirror has a peeling sheet, after peeling a peeling sheet from an adhesion layer, a film mirror can be affixed on a support base material through an adhesion layer.

The release sheet is a member that covers the surface opposite to the light incident side of the adhesive layer in the film mirror.

For example, when the film mirror is shipped, the release sheet is attached to the adhesive layer, and then the release sheet is released from the adhesive layer of the film mirror, and the film mirror is attached to the support substrate to reflect the solar power generation reflection device. Can be formed.

The release sheet may be any sheet that can protect the adhesiveness of the adhesive layer. For example, an acrylic film or sheet, a polycarbonate film or sheet, a polyarylate film or sheet, a polyethylene naphthalate film or sheet, a polyethylene terephthalate film Or a plastic film or sheet such as a sheet, a fluorine film, a resin film or sheet kneaded with titanium oxide, silica, aluminum powder, copper powder, etc., or a metal such as aluminum is applied to the resin kneaded with these. A resin film or sheet subjected to surface processing such as vapor deposition is used.

The thickness of the release sheet is not particularly limited, but is usually preferably in the range of 12 to 250 μm.

(Hard coat layer)
The hard coat layer is provided for the purpose of preventing damage to the surface of the film mirror and adhesion of dirt. The transparent hard coat layer is preferably the outermost layer on the light incident side, or the second or third layer from the light incident side. Another thin layer (preferably 1 μm or less) may be provided on the hard coat layer. More preferably, the hard coat layer is particularly preferably provided on the light incident side surface of the translucent resin layer.

Alternatively, the hard coat layer may be in the form of a single layer or a laminate of two or more layers. In the latter case, each layer may have the same composition or different compositions.

Examples of methods for producing the hard coat layer include conventionally known coating methods such as a gravure coating method, a reverse coating method, and a die coating method. In addition to applying and coating a predetermined material, various surface treatments and the like may be combined.

The thickness of the hard coat layer is preferably 0.05 μm or more and 10 μm or less from the viewpoint of preventing the film mirror from warping while obtaining sufficient scratch resistance. More preferably, they are 1 micrometer or more and 7 micrometers or less.

The material for forming the hard coat layer is not particularly limited as long as transparency, weather resistance, hardness, mechanical strength, and the like can be obtained. The hard coat layer can be composed of an acrylic resin, urethane resin, melamine resin, epoxy resin, organic silicate compound, silicone resin, or the like. In particular, silicone resins and acrylic resins are preferable in terms of hardness and durability. Furthermore, in terms of curability, flexibility, and productivity, active energy ray-curable acrylic resins or thermosetting acrylic resins are preferable, but there are concerns about weather resistance, and hard There is a concern that discoloration as a coating layer occurs with time and haze increases, resulting in a decrease in reflectance. For this reason, metalloxane (an organic silicate compound, a silicone resin) is preferably used in terms of high surface protection and weather resistance. That is, the hard coat layer is preferably a metalloxane-based hard coat layer.

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.), Toagosei 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.), Kyoeisha Chemical Co., Ltd .; (Product name “Light Ester” series, “Light acrylate” series, etc.) Kill.

More specifically, for example, a resin curable by electron beam or ultraviolet irradiation, a thermosetting resin, or the like can be used. In particular, a thermosetting silicone hard coat composed of a partially hydrolyzed oligomer of an alkoxysilane compound, a heat A hard coat made of a curable polysiloxane resin, an ultraviolet curable acrylic hard coat made of an acrylic compound having an unsaturated group, and a thermosetting inorganic material are preferable. As materials that can be used for the hard coat layer, an aqueous colloidal silica-containing acrylic resin (Japanese Patent Laid-Open No. 2005-66824), a polyurethane-based resin composition (Japanese Patent Laid-Open No. 2005-110918), and an aqueous silicone compound as a binder. Resin film used (Japanese Patent Laid-Open No. 2004-142161), photocatalytic oxide-containing silica film such as titanium oxide or alumina, photocatalytic film such as titanium oxide or niobium oxide having a high aspect ratio (Japanese Patent Laid-Open No. 2009-62216), photocatalyst Examples thereof include a fluorine-containing resin coating (Pierex Technologies), an organic / inorganic polysilazane film, and a film using a hydrophilization accelerator (AZ Electronics) in organic / inorganic polysilazane.

For the thermosetting silicone hard coat layer, a partially hydrolyzed oligomer of an alkoxysilane compound synthesized by a known method can be used. An example of the synthesis method is as follows. First, tetramethoxysilane or tetraethoxysilane is used as an alkoxysilane compound, and a predetermined amount of water is added to the alkoxysilane compound in the presence of an acid catalyst such as hydrochloric acid or nitric acid to remove by-produced alcohol from room temperature to 80 ° C. React with. By this reaction, the alkoxysilane is hydrolyzed, and further, a partially hydrolyzed oligomer of the alkoxysilane compound having an average polymerization degree of 4 to 8 having two or more silanol groups or alkoxy groups in one molecule is obtained by the condensation reaction. Next, a curing catalyst such as acetic acid or maleic acid is added to this and dissolved in an alcohol or glycol ether organic solvent to obtain a thermosetting silicone hard coat liquid. And this is apply | coated to the outer surface of a film mirror etc. by the coating method in a normal coating material, and a transparent hard-coat layer is formed by heat-hardening at the temperature of 80-140 degreeC. However, in this case, the setting of the curing temperature below the thermal deformation temperature of the film mirror is a prerequisite. In addition, by using di (alkyl or aryl) dialkoxysilane and / or mono (alkyl or aryl) trialkoxysilane instead of tetraalkoxysilane, a polysiloxane-based transparent hard coat layer is similarly produced. Is possible.

For the ultraviolet curable acrylic hard coat layer, for example, an acrylic compound having an unsaturated group, such as pentaerythritol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethyloltetra A polyfunctional (meth) acrylate mixture such as (meth) acrylate can be used, and a photopolymerization initiator such as benzoin, benzoin methyl ether, or benzophenone is blended and used. And this is apply | coated to the outer surface of a reflective film base material, and a transparent hard-coat layer is formed by carrying out ultraviolet curing.

Further, it is preferable to impart a hydrophilic property by subjecting the hard coat layer to a surface treatment. Examples of the treatment for imparting hydrophilicity include corona treatment (Japanese Patent Laid-Open No. 11-172028), plasma surface treatment, ultraviolet / ozone treatment, surface protrusion formation (Japanese Patent Laid-Open No. 2009-226613), surface fine processing treatment, and the like. Can be mentioned.

When the hard coat layer is made of an inorganic material, for example, silicon oxide, aluminum oxide, silicon nitride, aluminum nitride, lanthanum oxide, lanthanum nitride, or the like can be formed by vacuum film formation. Examples of the vacuum film forming method include a resistance heating vacuum deposition method, an electron beam heating vacuum deposition method, an ion plating method, an ion beam assisted vacuum deposition method, and a sputtering method.

Further, when the hard coat layer is made of an inorganic material, it is preferably made of a film obtained by coating polysilazane and heat-curing it. When the precursor of the hard coat layer contains polysilazane, for example, after applying a solution to which a catalyst is added as necessary in an organic solvent containing polysilazane represented by the following general formula (6), the solvent is evaporated. Thereby leaving a polysilazane layer having a layer thickness of 0.05 to 3.0 μm on the film mirror. Then, a glass-like transparent hard coat film is formed on the film mirror by locally heating the polysilazane layer in the presence of oxygen, active oxygen, and in some cases nitrogen in an atmosphere containing water vapor. It is preferable to adopt the method.

In the general formula (6), R ¹ , R ² and R ³ are the same or different and are independently of each other a hydrogen atom or an optionally substituted alkyl group, aryl group, vinyl group or (trialkoxy). (Silyl) alkyl group, preferably hydrogen atom, methyl group, ethyl group, propyl group, iso-propyl group, butyl group, iso-butyl group, tert-butyl group, phenyl group, vinyl group or 3- (triethoxysilyl) Represents a group selected from the group consisting of a propyl group and a 3- (trimethoxysilylpropyl) group. In this case, n is an integer, and n is determined so that the polysilazane has a number average molecular weight of 150 to 150,000 g / mol.

As catalysts, preferably basic catalysts, in particular N, N-diethylethanolamine, N, N-dimethylethanolamine, triethanolamine, triethylamine, 3-morpholinopropylamine or N-heterocyclic compounds are used. . The catalyst concentration is usually in the range of 0.1 to 10 mol%, preferably 0.5 to 7 mol%, based on polysilazane.

In one preferred embodiment, a solution containing perhydropolysilazane in which all of R ¹ , R ² and R ^{3 in} the general formula (6) are hydrogen atoms is used.

In another preferred embodiment, the hard coat layer contains at least one polysilazane represented by the following general formula (7).

In the general formula (7), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or an optionally substituted alkyl group, aryl group, vinyl group or Represents a (trialkoxysilyl) alkyl group. In this case, n and p are integers, and in particular, n is determined so that polysilazane has a number average molecular weight of 150 to 150,000 g / mol.

Particularly preferred are compounds in which R ¹ , R ³ and R ⁶ represent a hydrogen atom, and R ² , R ⁴ and R ⁵ represent a methyl group. A compound in which R ¹ , R ³ and R ⁶ represent a hydrogen atom, R ² and R ⁴ represent a methyl group, and R ⁵ represents a vinyl group. R ¹ , R ³ , R ⁴ and R ⁶ represent a hydrogen atom, and R ² and R ⁵ represent a methyl group.

Furthermore, in another preferred embodiment, the transparent hard coat layer contains at least one polysilazane represented by the following general formula (8).

In general formula (8), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are independently of each other a hydrogen atom or optionally substituted. Represents an alkyl group, an aryl group, a vinyl group or a (trialkoxysilyl) alkyl group; In this case, n, p and q are integers, and in particular, n is determined so that polysilazane has a number average molecular weight of 150 to 150,000 g / mol.

Particularly preferred are R ¹ , R ³ and R ⁶ represent a hydrogen atom, R ² , R ⁴ , R ⁵ and R ⁸ represent a methyl group, R ⁹ represents a (triethoxysilyl) propyl group, R ⁷ is a compound representing an alkyl group or a hydrogen atom.

The proportion of polysilazane in the solvent is generally 1 to 80% by mass, preferably 5 to 50% by mass, and particularly preferably 10 to 40% by mass.

As the solvent, in particular, an organic solvent which does not contain water and a reactive group (for example, a hydroxy group or an amine group) and is inert to polysilazane, preferably an aprotic solvent is suitable. This includes, for example, aliphatic or aromatic hydrocarbons, halogen hydrocarbons, esters such as ethyl acetate or butyl acetate, ketones such as acetone or methyl ethyl ketone, ethers such as tetrahydrofuran or dibutyl ether, and mono- and polyalkylene glycol dialkyl ethers (Diglymes) or a mixture of these solvents.

As an additional component of this polysilazane solution, further binders such as those conventionally used in the production of paints can be used. For example, cellulose ethers and cellulose esters such as ethyl cellulose, nitrocellulose, cellulose acetate or cellulose acetobutyrate, natural resins such as rubber or rosin resins, or synthetic resins such as polymerized resins or condensed resins such as aminoplasts, in particular Urea resins and melamine formaldehyde resins, alkyd resins, acrylic resins, polyesters or modified polyesters, epoxides, polyisocyanates or blocked polyisocyanates, or polysiloxanes.

Further, as another component to be further added to the polysilazane preparation, for example, an additive that affects the viscosity, wettability of the preparation, film forming property, lubricating action or exhaust property, or inorganic nanoparticles such as SiO ₂ TiO ₂ , ZnO, ZrO ₂ or Al ₂ O ₃ can be used.

The transparent hard coat layer of polysilazane thus formed can also be used as an oxygen / water vapor barrier film.

Also, as a particularly preferable example of the transparent hard coat layer, a hard coat layer containing a polyfunctional acrylic monomer and a silicone resin can be given. Here, as one form of the hard coat layer, for example, there is a metalloxane-based hard coat layer. The polyfunctional acrylic monomer is hereinafter referred to as “A” component, and the silicone resin is hereinafter referred to as “B” component.

The polyfunctional acrylic monomer “A” component preferably has an unsaturated group, particularly an active energy ray-reactive unsaturated group. The active energy ray referred to in this specification preferably means an electron beam or an ultraviolet ray. As the polyfunctional acrylic monomer having an active energy ray-reactive unsaturated group, a radical polymerization monomer is used, preferably a bifunctional or higher functional monomer having an α, β-unsaturated double bond in the molecule. A certain polyfunctional acrylate type or polyfunctional methacrylate type monomer may be mentioned. In addition, a vinyl monomer, an allyl monomer, or a monofunctional monomer may be included. Further, the radical polymerization monomer can be used alone or in combination of two or more kinds of monomers in order to adjust the crosslinking density. As the “A” component, in addition to these relatively low molecular weight compounds, for example, so-called narrowly-defined monomers having a molecular weight of less than 1000, oligomers and prepolymers having a somewhat high molecular weight, for example, a weight average molecular weight of 1,000 to 10,000 are also used. Is possible.

Specific examples of monofunctional (meth) acrylate monomers include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, and 2- (meth) acryloyloxyethyl. Hexahydrophthalate, 2- (meth) acryloyloxypropyl phthalate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate 2-hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, benzyl (meth) acrylate, butanediol mono (Meth) acrylate, butoxyethyl (meth) acrylate, butyl (meth) acrylate, caprolactone (meth) acrylate, cetyl (meth) acrylate, cresol (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, Dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, dipropylene glycol (meth) acrylate, phenyl (meth) acrylate, ethyl (Meth) acrylate, isoamyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) ) Acrylate, isooctyl (meth) acrylate, isostearyl (meth) acrylate, isomyristyl (meth) acrylate, lauroxy polyethylene glycol (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene Glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methyl (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene Glycol (meth) acrylate, octafluoropentyl (meth) acrylate, Octoxy polyethylene glycol-polypropylene glycol (meth) acrylate, octyl (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, perfluorooctylethyl (meth) acrylate, phenoxy (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, Phenoxyethyl (meth) acrylate, phenoxyhexaethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, stearyl (meth) acrylate, succinic acid (meth) acrylate, t-butyl (meth) ) Acrylate, t-butylcyclohexyl (meth) acrylate, tetrafluoropropyl (meth) Chryrate, tetrahydrofurfuryl (meth) acrylate, tribromophenyl (meth) acrylate, tridecyl (meth) acrylate, trifluoroethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, ω-carboxy-polycaprolactone (meth) Examples thereof include acrylates, derivatives thereof, and modified products.

Specific examples of the polyfunctional (meth) acrylate monomer include 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol F di (meth) acrylate, diethylene glycol di (meth) acrylate, hexahydrophthalic acid di (meth) acrylate, neopentyl hydroxypivalate Glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hydroxypivalate ester neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, di (meth) acrylate phthalate Rate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene Glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, tripropylene glycol di (meth) acrylate , Triglycerol di (meth) acrylate, dipropylene glycol di (meth) acrylate, glycerol tri (meth) acrylate, pentaerythritol Litol tri (meth) acrylate, phosphoric acid tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane benzoate tri (meth) acrylate, tris ((meth) acryloxyethyl) isocyanurate, di (meth) acrylic Isocyanurate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and derivatives and modified products thereof It is done.

Examples of such commercially available “A” component that is a polymerizable organic compound include Aronix M-400, M-408, M-450, M-305, M-309, M-manufactured by Toagosei Co., Ltd. 310, M-315, M-320, M-350, M-360, M-208, M-210, M-215, M-220, M-225, M-233, M-240, M-245, M-260, M-270, M-1100, M-1200, M-1210, M-1310, M-1600, M-221, M-203, TO-924, TO-1270, TO-1231, TO- 595, TO-756, TO-1343, TO-902, TO-904, TO-905, TO-1330, KAYARAD D-310, D-330, DPHA, DPCA-20, DP manufactured by Nippon Kayaku Co., Ltd. A-30, DPCA-60, DPCA-120, DN-0075, DN-2475, SR-295, SR-355, SR-399E, SR-494, SR-9041, SR-368, SR-415, SR- 444, SR-454, SR-492, SR-499, SR-502, SR-9020, SR-9035, SR-111, SR-212, SR-213, SR-230, SR-259, SR-268, SR-272, SR-344, SR-349, SR-601, SR-602, SR-610, SR-9003, PET-30, T-1420, GPO-303, TC-120S, HDDA, NPGDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620, R-551, R-712, R-167, R-526, -551, R-712, R-604, R-684, TMPTA, THE-330, TPA-320, TPA-330, KS-HDDA, KS-TPGDA, KS-TMPTA, Kyoeisha Chemical Co., Ltd. light acrylate PE -4A, DPE-6A, DTMP-4A and the like.

The content of the polyfunctional acrylic monomer “A” component is 10 to 90% by mass with the total composition of “A” + “B” being 100% by mass from the viewpoint of improving antifouling properties and light resistance. It is preferably 15 to 80% by mass.

The silicone resin “B” component is preferably a silicone resin having an active energy ray-reactive unsaturated group. The silicone resin contains a polyorganosiloxane, and is preferably a compound having a polyorganosiloxane chain having an active energy ray-curable unsaturated bond in the molecule. In particular, the silicone resin contains 1 to 50% by mass of the monomer (a) having a radically polymerizable double bond and a polyorganosiloxane chain, and other than (a) having a radically polymerizable double bond and a reactive functional group. A monomer containing 10 to 95% by mass of the monomer (b) and 0 to 89% by mass of the monomer (c) having a radical polymerizable double bond other than (a) and (b) is polymerized. A vinyl copolymer having a number average molecular weight of 5,000 to 100,000 obtained by reacting the polymer (α) with a functional group capable of reacting with the reactive functional group and a compound (β) having a radical polymerizable double bond. An active energy ray-curable resin that is a coalescence is preferable.

Specific examples of the monomer (a) having a radical polymerizable double bond and a polyorganosiloxane chain include, for example, one end of Silaplane FM-0711, FM-0721, FM-0725, etc. manufactured by Chisso Corporation. Examples include (meth) acryloxy group-containing polyorganosiloxane compounds, AC-SQ SI-20 manufactured by Toagosei Co., Ltd., POSS (Polyhydrogen Oligomeric Silsesquioxane) series acrylates and methacrylate-containing compounds manufactured by Hybrid Plastics.

The “B” component can be used alone or in combination of two or more depending on the required performance. The polymerization ratio is preferably such that the monomer (a) is 1 to 50% by mass, more preferably 10 to 35% by mass, based on the total mass of monomers constituting the polymer. %. When the copolymerization ratio of the “B” component is less than 1% by mass, it becomes difficult to impart antifouling properties and weather resistance to the upper surface of the cured product, and when it exceeds 50% by mass, scratch resistance is obtained. In addition, the coating composition performance such as compatibility with other components contained in the active energy ray-curable composition, adhesion to the substrate, toughness, and solubility of the polymer in the solvent are obtained. It becomes difficult. An appropriate amount of polysiloxane can also be contained in the above components, and depending on the chemical structure and quantitative ratio of the “B” component, the durability can be improved by adding polysiloxane.

Alternatively, the metalloxane-based hard coat material may be a commercially available product. For example, there is a Surcoat series (for example, BP-16 N) manufactured by Doken Co., Ltd. In addition, surcoat series (for example, NP-720, NP-730) manufactured by Doken Co., Ltd., polysiloxane compounds such as OCD T7, OCD T11, OCD T12 manufactured by Tokyo Ohka Kogyo Co., Ltd., Toagosei Co., Ltd. Silicone copolymers such as Cymac US-150, US-270, US-350, US-450, Reseda GP-700 (or more), etc. may be used as the hard coat material.

This hard coat layer is preferably flexible and does not warp. The transparent hard coat layer on the outermost surface layer of the film mirror may form a dense cross-linked structure, so the film may be bent or it may be prone to cracking due to lack of flexibility and handling. It becomes difficult. In such a case, it is preferable to design so as to obtain flexibility and flatness by adjusting the amount of the inorganic substance in the hard coat layer composition.

Further, the hard coat layer may contain an ultraviolet absorber or an antioxidant. As the ultraviolet absorber or antioxidant, the ultraviolet absorber or antioxidant used in the above-described translucent resin layer can be used. As the antioxidant used in the hard coat layer, it is preferable to use an organic antioxidant such as a phenol-based antioxidant, a thiol-based antioxidant, and a phosphite-based antioxidant. The falling angle can also be reduced by including an organic antioxidant in the hard coat layer. An antioxidant and a light stabilizer may be used in combination. Here, when used together with the antioxidant of the light reflecting layer and the light stabilizer, the light stabilizer is not particularly limited, but the same light stabilizer as described in the above-mentioned section of the light transmissive resin layer can be used. Description is omitted.

In particular, a preferred UV absorber in a hard coat layer containing a polyfunctional acrylic monomer and a silicone resin is a benzotriazole UV absorber. By including a benzotriazole-based ultraviolet absorber in the hard coat layer, it is possible to obtain an excellent effect that not only the weather resistance is further improved, but also the falling angle can be further reduced. In particular, when the compound represented by the following general formula (9) is contained in the hard coat layer, the effect of reducing the falling angle is remarkable. The falling angle refers to a value obtained by dropping a water drop on a horizontal mirror and then gradually increasing the tilt angle of the mirror, and measuring the minimum angle at which the water drop of a predetermined mass that has been stationary falls. Say. It can be said that the smaller the tumbling angle, the easier the water droplets to roll off the surface, and the surface to which the water droplets hardly adhere.

The amount of the UV absorber used in the hard coat layer is preferably 0.1 to 20% by mass in order to improve the weather resistance while maintaining good adhesion. More preferably, it is 0.25 to 15% by mass, and more preferably 0.5 to 10% by mass.

The hard coat layer, particularly the hard coat layer containing a polyfunctional acrylic monomer and a silicone resin, preferably contains an initiator for initiating polymerization. Photoinitiators of active energy ray-curable resins such as ultraviolet rays are preferably used. Examples include benzoin and derivatives thereof, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and the like. Moreover, you may use an initiator with a photosensitizer. The above initiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate initiator, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used. The initiator or photosensitizer is used in an amount of 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, more preferably 2 to 5 parts by weight, based on 100 parts by weight of the composition. Two types of initiators can be used in combination. In particular, in the case of radical initiators, at least two types of initiators, preferably radical initiators that absorb different wavelengths, are used. More preferably, two kinds of initiators having different ultraviolet absorption wavelengths are used. For example, with only an initiator that absorbs a shorter wavelength, the polymerization reaction of all the monomers may not be performed by the initiator. On the other hand, only an initiator that absorbs longer wavelengths improves the reactivity, but the initiator may be colored during long-term use. Therefore, it is preferable to use radical initiators that absorb different wavelengths in order to improve the weather resistance and also the polymerization reactivity without coloring even during long-term use.

In the hard coat layer, various additives can be further blended as necessary. For example, a surfactant, a leveling agent and an antistatic agent can be used.

¡Leveling agents are effective in reducing surface irregularities. 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.

(Anchor layer)
The anchor layer can be disposed between the resin substrate and the light reflecting layer. An anchor layer consists of resin and makes a resin base material and a light reflection layer closely_contact | adhere. Therefore, the anchor layer has an adhesion property that allows the resin base material and the light reflection layer to adhere to each other, heat resistance that can withstand heat when the light reflection layer is formed by a vacuum deposition method, and the high reflection that the light reflection layer originally has. Smoothness is required to bring out performance.

The material used for the anchor layer (resin material) and the method for forming the anchor layer are not particularly limited. For example, it is disclosed in known documents such as WO 2012/165460 pamphlet (particularly, paragraphs “0209” to “0212”). Similar materials and methods as described can be used.

(Corrosion prevention layer)
The corrosion prevention layer is a resin layer containing a corrosion inhibitor and is preferably adjacent to the light reflection layer. For example, it can be provided between the light reflecting layer and the adhesive layer.

The corrosion prevention layer may consist of only one layer or a plurality of layers. The thickness of the corrosion prevention layer is preferably 1 to 10 μm, more preferably 2 to 8 μm.

The resin and corrosion inhibitor used in the corrosion prevention layer are not particularly limited, but are similar to those described in known documents such as WO 2012/165460 pamphlet (particularly, paragraphs “0079” to “0095”). Material can be used.

A corrosion prevention layer can be formed by applying and coating these resin materials (binders) on the light reflection layer 1 or the like.

As the corrosion inhibitor, it is preferable to have an adsorptive group for silver. Here, the term “corrosion” refers to a phenomenon in which metal (silver) is chemically or electrochemically eroded or deteriorated by the environmental material surrounding it (see JIS Z0103-2004).

The optimum content of the corrosion inhibitor varies depending on the compound used, but is generally preferably in the range of 0.1 to 1.0 g / m ² .

(Gas barrier layer)
The gas barrier layer is preferably provided on the light incident side with respect to the light reflecting layer. In particular, it is preferable to provide a gas barrier layer between the resin substrate and the light reflecting layer.

The gas barrier layer is intended to prevent the deterioration of humidity, especially the deterioration of the resin base material and each component layer supported by the resin base material due to high humidity, but with special functions and applications. As long as it has a function of preventing deterioration, a gas barrier layer of various modes can be provided. As the moisture resistance of the gas barrier layer, the water vapor permeability at 40 ° C. and 90% RH is preferably 1 g / m ² · day or less, more preferably 0.5 g / m ² · day or less, still more preferably It is 0.2 g / m ² · day or less. In addition, the oxygen permeability of the gas barrier layer is preferably 0.6 ml / m ² / day / atm or less under the conditions of a measurement temperature of 23 ° C. and a humidity of 90% RH.

The material used for the gas barrier layer and the method for forming the gas barrier layer are not particularly limited, and are described in known documents such as WO 2012/165460 pamphlet (particularly, paragraphs “0188” to “0209”). The same materials and methods can be used.

(Film mirror manufacturing method)
A film mirror for solar power generation can be manufactured by appropriately laminating the above-described constituent layers. Hereinafter, although preferable embodiment of the manufacturing method of the film mirror shown by FIG. 1A is described, this invention is not limited to the following form.

First, a resin base material (for example, a polyethylene terephthalate film manufactured by melt film formation) is prepared. If necessary, an anchor layer is formed by applying a predetermined resin material on the resin substrate (after application, drying if necessary). Next, a light reflecting layer (for example, a silver reflecting layer) is formed on the resin substrate (or an anchor layer when an anchor layer is provided on the resin substrate) by a method such as vacuum deposition.

Separately, the urethane-modified acrylic resin solution is prepared by dissolving the urethane-modified acrylic resin in a suitable solvent. Here, the solvent that can be used for preparing the urethane-modified acrylic resin liquid is not particularly limited as long as it can dissolve the urethane-modified acrylic resin, and is appropriately selected depending on the type of the urethane-modified acrylic resin to be used. For example, methyl ethyl ketone (MEK), toluene, xylene, methylene chloride, 1,2-dichloroethane, cyclohexane, ethyl acetate, t-butyl acetate, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl Examples include alcohol, sec-butyl alcohol butanol, methyl cellosolve, 4-methoxy-4-methyl-2-pentanone, ethyl cellosolve, tetrahydrofuran, 1-dioxane, 1,3-dioxolane, pyridine, and diethylamine. Is not to be done. These solvents can be used alone or in combination of two or more. The concentration of the urethane-modified acrylic resin in the urethane-modified acrylic resin liquid is not particularly limited, but is preferably 5 to 30% by mass, more preferably in consideration of ease of application, ease of adjusting a desired thickness, and the like. 5 to 15% by mass.

Next, after applying the urethane-modified acrylic resin solution prepared above on the resin substrate or the light reflecting layer, the urethane-modified acrylic resin layer is formed by drying the coating film. Here, the application method is not particularly limited, but roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method, blade coating method, bar coating method, gravure coating method, curtain coating. Methods, such as a spray coating method and a doctor coating method, can be used. The drying conditions are not particularly limited as long as a sufficient amount of solvent can be evaporated from the coating film (a urethane-modified acrylic resin layer can be formed). Specifically, the drying temperature is preferably 60 to 100 ° C, more preferably 70 to 90 ° C. The drying time is preferably 0.5 to 2 minutes, more preferably 0.5 to 1.5 minutes.

Furthermore, on the urethane-modified acrylic resin layer formed in this manner, a translucent resin layer forming liquid containing a resin material and an ultraviolet absorber is applied (after application, if necessary, dried), A translucent resin layer is formed. Here, the solvent that can be used for the preparation of the translucent resin layer forming liquid is not particularly limited as long as it can dissolve the resin material and the ultraviolet absorber, and is appropriately selected depending on the type of the resin material and the ultraviolet absorber to be used. Selected. For example, methyl ethyl ketone (MEK), toluene, xylene, methylene chloride, 1,2-dichloroethane, cyclohexane, ethyl acetate, t-butyl acetate, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl Examples include alcohol, sec-butyl alcohol butanol, methyl cellosolve, 4-methoxy-4-methyl-2-pentanone, ethyl cellosolve, tetrahydrofuran, 1-dioxane, 1,3-dioxolane, pyridine, and diethylamine. Is not to be done. These solvents can be used alone or in combination of two or more. The concentration of the resin material (translucent resin) in the translucent resin layer forming liquid is not particularly limited, but it is preferably 10 to 40 in consideration of ease of application, ease of adjusting a desired thickness, and the like. % By mass, more preferably 15 to 30% by mass. Moreover, it does not restrict | limit especially as a coating method, The method similar to the coating method of the said urethane modified acrylic resin liquid is applicable. After the translucent resin layer forming liquid is applied on the urethane-modified acrylic resin layer, the drying condition when drying is such that a sufficient amount of solvent can be evaporated from the coating film (the translucent resin layer can be formed). There is no particular limitation. Specifically, the drying temperature is preferably 60 to 100 ° C, more preferably 70 to 90 ° C. The drying time is preferably 0.5 to 5 minutes, more preferably 1 to 3 minutes.

Next, a hard coat layer forming liquid containing a hard coat material is applied onto the thus formed translucent resin layer (after application, dried if necessary, and further cured as necessary). To form a hard coat layer. Here, the solvent that can be used for the preparation of the hard coat layer forming liquid is not particularly limited as long as it can dissolve the hard coat material, and is appropriately selected depending on the type of the hard coat material to be used. Specifically, the same solvent as the solvent that can be used for the preparation of the translucent resin layer forming liquid can be used. These solvents can be used alone or in combination of two or more. The concentration of the hard coat material in the hard coat layer forming liquid is not particularly limited, but is preferably 20 to 40% by mass, more preferably 25 in consideration of ease of application, ease of adjusting a desired thickness, and the like. Is 35% by mass. Moreover, it does not restrict | limit especially as a coating method, The method similar to the coating method similar to the said urethane-modified acrylic resin layer is applicable. The drying conditions for drying after applying the hard coat layer forming liquid on the translucent resin layer are not particularly limited as long as a sufficient amount of solvent can be evaporated from the coating film (a hard coat layer can be formed). . Specifically, the drying temperature is preferably 70 to 100 ° C., more preferably 80 to 90 ° C. The drying time is preferably 0.5 to 3.0 minutes, more preferably 0.5 to 1.5 minutes. In the case where a thermosetting hard coat material is used, the drying and curing can be performed simultaneously.

Further, an adhesive material is formed on the back side of the light reflecting layer or the resin base (the side on which the resin base and the light reflecting layer are not formed respectively) to form an adhesive layer, and the adhesive layer is covered with a release sheet. As a result, a film mirror is manufactured.

When manufacturing film mirrors having layers other than those described above, the desired film mirrors are manufactured by laminating the constituent layers necessary for each film mirror in a predetermined order on the resin base material or light reflecting layer. Can do. For example, when the anchor coat layer is formed between the resin base material and the light reflecting layer, a predetermined resin material (an anchor coat layer forming liquid containing a predetermined resin material if necessary) is formed on the resin base material. ) Is applied (after application, it is dried if necessary) to form an anchor coat layer. Here, the solvent, drying conditions, and the like that can be used for the preparation of the anchor coat layer forming liquid are not limited. For example, the same description as above can be applied, and thus the description thereof is omitted here. Similarly, when the corrosion prevention layer is formed between the light reflection layer and the adhesive layer, a resin material containing a corrosion inhibitor on the light reflection layer (if necessary, a predetermined resin material and corrosion). It is possible to form a corrosion prevention layer by applying (corrosion prevention layer forming liquid containing an inhibitor) (after application, drying if necessary). Here, the solvent, drying conditions, and the like that can be used for the preparation of the corrosion-preventing layer forming liquid are not limited. When the film mirror has a gas barrier layer, the gas barrier layer can be formed by subjecting a predetermined layer to a sol-gel method and heating / UV treatment.

And in the film mirror of the present invention, only the resin base material is a resin film produced by melt film formation, etc., the resin film is not used for the other constituent layers, and sequentially with respect to the resin base material, It is preferable to manufacture a film mirror by repeating film formation by application, coating, vapor deposition, or the like of each constituent layer and laminating predetermined constituent layers. That is, the method for producing a film mirror of the present invention includes a resin film having at least a light reflecting layer, a layer disposed on the light incident side (for example, a translucent resin layer containing an ultraviolet absorber, a urethane-modified acrylic resin layer), It is preferable that the process which manufactures separately the resin film which becomes and does not include the process of bonding any two resin films with an adhesive agent (adhesive layer) after that is preferable.

(Reflector for solar thermal power generation)
The solar power generation reflecting device is a reflecting mirror that includes a film mirror and a self-supporting support base material, and the film mirror is bonded to the support base material via an adhesive layer.

In addition, the "self-supporting property" as used herein means that the supporting substrate supports the edge portion of the film mirror in a state where the supporting substrate is cut to a size used as a supporting substrate of the solar power generation reflecting device. This means that the film mirror has rigidity enough to support the film mirror. The support base material of the solar power generation reflecting device has self-supporting properties, so that it is easy to handle when installing the solar power generation reflecting device, and the holding member for holding the solar power generation reflecting device has a simple configuration. Therefore, it is possible to reduce the weight of the reflection device itself, and it is possible to suppress power consumption during solar tracking.

(Supporting substrate)
As a self-supporting support base material, there are one having a pair of metal flat plates and an intermediate layer interposed between the metal flat plates (type A), or one made of a resin material having a hollow structure (type B). It is preferable. For a specific configuration, self-supporting substrates A and B described in WO 11/162154 pamphlet or US Patent Application Publication No. 2013/0114155 can be employed.

(Holding member)
The solar power generation reflection device has a holding member that holds the reflection device itself.

It is preferable that the holding member holds the reflecting surface (film mirror) of the solar power generation reflecting device in a state where the sun can be tracked. The form of the holding member is not particularly limited, but for example, a plurality of places on the support base on the back side of the solar power generation reflecting device are formed in a bar shape so that the solar power generating reflection device can hold a desired shape and posture. The form held by a columnar member or a beam-like member is preferable.

The holding member has a configuration for holding the solar power generation reflecting device in a state in which the sun can be tracked. However, in the case of solar tracking, the holding member may be driven manually, or a separate driving device may be provided to automatically track the sun. It is good also as composition to do.

The effect of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

Example 1
A biaxially stretched polyester film (polyethylene terephthalate film, thickness: 25 μm) was used as the resin substrate. A silver reflective layer having a thickness of 100 nm was formed as a light reflective layer on one side of the resin base material by a vacuum deposition method.

Urethane-modified acrylic resin (manufactured by Taisei Fine Chemical Co., Ltd., 8UA-239; hydroxyl value = 30 mgKOH / g, molecular weight = 30,000, urethane / acrylic ratio = 20/80) is adjusted to a concentration of 10% by mass with methyl ethyl ketone (MEK). To prepare a urethane-modified acrylic resin layer forming solution. The urethane-modified acrylic resin layer forming liquid prepared in this way is applied to the surface of the polyethylene terephthalate film on the side where the light reflecting layer is not formed by gravure coating so that the thickness (dry film thickness) is 1 μm. Then, a urethane-modified acrylic resin layer having a thickness of 1 μm was formed by drying at 80 ° C. for 1 minute.

PMMA resin (manufactured by Mitsubishi Rayon Co., Ltd., EMB457), acrylic rubber (manufactured by Asahi Kasei Chemicals Co., Ltd., SRB215), triazine ultraviolet absorber (manufactured by BASF, Tinuvin479), benzotriazole ultraviolet absorber (manufactured by BASF, Tinuvin928) Is mixed in methyl ethyl ketone (MEK) so that the mixing ratio is 17: 3: 0.68: 0.43 (solid content ratio) and the solid content concentration is 21% by mass, and the translucent resin layer is mixed. A forming solution was prepared. This translucent resin layer forming solution is applied on the urethane-modified acrylic resin layer formed above with a bar coater so that the thickness (dry film thickness) is 25 μm, and dried at 80 ° C. for 2 minutes. Thus, a translucent resin layer having a thickness of 25 μm was formed. The amount of the ultraviolet absorber in the translucent resin layer (total amount of triazine-based ultraviolet absorber and benzotriazole-based ultraviolet absorber; solid content conversion) was 5% by mass.

A metalloxane-based silicone liquid (manufactured by Doken Co., Ltd., acrylic silicone-based thermosetting resin, Surcoat BP-16 N; 45% by mass methanol solution) is diluted with methyl ethyl ketone (MEK) to a concentration of 30% by mass. A hard coat layer forming solution was prepared. This hard coat layer forming liquid is applied on the translucent resin layer formed above by gravure coating so that the thickness (dry film thickness) becomes 3 μm, and dried / cured at 85 ° C. for 1 minute. Thus, a hard coat layer having a thickness of 3 μm was formed to obtain a film mirror 1.

Example 2
Example 1 except that the amount of the ultraviolet absorber in the translucent resin layer (total amount of triazine-based ultraviolet absorber and benzotriazole-based ultraviolet absorber; solid content conversion) in Example 1 was 15% by mass. In the same manner as described above, a film mirror 2 was obtained.

Example 3
Example 1 except that the amount of the ultraviolet absorber in the translucent resin layer (total amount of triazine-based ultraviolet absorber and benzotriazole-based ultraviolet absorber; solid content conversion) in Example 1 was changed to 1% by mass. In the same manner as described above, a film mirror 3 was obtained.

Example 4
In Example 1, the amount of the ultraviolet absorber in the translucent resin layer (total amount of triazine-based ultraviolet absorber and benzotriazole-based ultraviolet absorber; solid content conversion) was changed to 0.5% by mass. In the same manner as in Example 1, a film mirror 4 was obtained.

Example 5
In Example 4, the amount of the ultraviolet absorber in the translucent resin layer (total amount of triazine-based ultraviolet absorber and benzotriazole-based ultraviolet absorber; solid content conversion) was changed to 20% by mass. In the same manner as described above, a film mirror 5 was obtained.

Example 6
In Example 4, the film mirror 6 was obtained like Example 4 except not having formed the hard-coat layer.

Example 7
In Example 1, a film mirror 7 was obtained in the same manner as in Example 1 except that the hard coat layer was not formed.

Example 8
In Example 1, the hard coat layer was coated with an acrylic hard coat paint (Desolite Z7501 manufactured by JSR Corporation) in a gravure coating coating method so that the coating thickness after drying was 3 μm. Other than forming by irradiating with ultraviolet rays under conditions of 200 mJ / cm ² with a UV light irradiation device (Fusion UV Systems Japan Co., Ltd. product name: Fusion H bulb) after drying under the condition of ℃ × 1 minute. Obtained a film mirror 8 in the same manner as in Example 1.

Example 9
In Example 1, a film mirror 9 was obtained in the same manner as in Example 1 except that the thickness of the urethane-modified acrylic resin layer was 0.05 μm.

Example 10
In Example 1, a film mirror 10 was obtained in the same manner as in Example 1 except that the thickness of the urethane-modified acrylic resin layer was 0.1 μm.

Example 11
In Example 1, a film mirror 11 was obtained in the same manner as in Example 1 except that the thickness of the urethane-modified acrylic resin layer was 5 μm.

Example 12
In Example 1, except that the urethane-modified acrylic resin was made by Taisei Fine Chemical Co., Ltd., 8UA-017; hydroxyl value = 0 mgKOH / g, molecular weight = 40,000, urethane / acryl ratio = 50/50) In the same manner as in Example 1, a film mirror 12 was obtained.

Example 13
In Example 1, except that the urethane-modified acrylic resin was made by Taisei Fine Chemical Co., Ltd., 8UA-318; hydroxyl value = 17 mgKOH / g, molecular weight = 30,000, urethane / acryl ratio = 30/70) In the same manner as in Example 1, a film mirror 13 was obtained.

Comparative Example 1
A film mirror 14 was obtained in the same manner as in Example 4 except that the urethane-modified acrylic resin layer was not formed in Example 4.

Comparative Example 2
In Example 1, the film mirror 15 was obtained like Example 1 except not having formed the urethane-modified acrylic resin layer.

Comparative Example 3
In Example 7, the film mirror 16 was obtained like Example 7 except not having formed the urethane-modified acrylic resin layer.

Comparative Example 4
In Comparative Example 3, the same procedure as in Comparative Example 3 was performed except that the light-transmitting resin layer was formed without adding the UV absorber (that is, the amount of the UV absorber in the light-transmitting resin layer = 0% by mass). Thus, a film mirror 17 was obtained.

Comparative Example 5
In Example 7, the film mirror 18 was obtained like Example 7 except having formed the PMMA resin layer as follows instead of the urethane-modified acrylic resin layer.

(Formation of PMMA resin layer)
PMMA resin (manufactured by Mitsubishi Rayon, EMB457; molecular weight = 300,000) was diluted with methyl ethyl ketone (MEK) to a concentration of 5% by mass to prepare a PMMA resin layer forming solution. The PMMA resin layer forming solution thus prepared was applied to the surface of the polyethylene terephthalate film on the side where the light reflecting layer was not formed by gravure coating so that the thickness (dry film thickness) was 1 μm. The PMMA resin layer having a thickness of 1 μm was formed by drying at 80 ° C. for 1 minute.

[Evaluation]
For the film mirrors obtained in the above Examples and Comparative Examples, the initial specular reflectance and haze and durability test (after 85 ° C. × 1000 hours and 100 cycles (1 cycle = 10 ° C. × 12 hours and Coloring, regular reflectance and haze after 60 ° C. × 12 hours) were measured. The results are shown in Table 1 below.

<Measurement of regular reflectance>
A spectrophotometer “UV265” manufactured by Shimadzu Corporation was modified with an integrating sphere reflection accessory, and the incident angle of incident light was adjusted to 5 ° with respect to the normal of the reflecting surface. The regular reflectance at a reflection angle of 5 ° was measured. Evaluation was measured as an average reflectance (sunlight weighted average reflectance) (%) from 350 nm to 700 nm.

<Measurement of regular reflectance after durability test (left at 85 ° C. for 1000 hours)>
Each film mirror was allowed to stand for 1000 hours under the conditions of a temperature of 85 ° C. and a humidity of 85% RH, and then the regular reflectance of each film mirror was measured by the same method as the above-described regular reflectance measurement.

<Measurement of specular reflectance after durability test [(10 ° C. × 12 hours and 60 ° C. × 12 hours / cycle) × 100 cycles]>
For each film mirror, 10 cycles of 10 ° C. × 12 hours and 60 ° C. × 12 hours were repeated 100 cycles, and then the regular reflectance of each film mirror was measured by the same method as the measurement of regular reflectance.

<Measurement of haze>
The haze of each film mirror was measured using Haze Meter NDH7000 manufactured by Nippon Denshoku Industries Co., Ltd.

<Measurement of haze after durability test (after standing at 85 ° C. × 1000 hours)>
Each film mirror was allowed to stand for 1000 hours under the conditions of a temperature of 85 ° C. and a humidity of 85% RH, and then the haze of each film mirror was measured by the same method as the above haze measurement.

<Measurement of haze after durability test [(10 ° C. × 12 hours and 60 ° C. × 12 hours / cycle) × 100 cycles]>
Each film mirror was repeated 100 cycles with 10 ° C. × 12 hours and 60 ° C. × 12 hours as one cycle, and then the haze of each film mirror was measured by the same method as the measurement of haze.

<Evaluation of coloring after durability test (after standing at 85 ° C. × 1000 hours)>
Each film mirror was cut into 10 cm × 10 cm and allowed to stand for 1000 hours under conditions of a temperature of 85 ° C. and a humidity of 85% RH, and then each film mirror was visually observed from the hard coat layer side, and the degree of color change was evaluated by the following score.

<Evaluation of coloring after durability test [(10 ° C. × 12 hours and 60 ° C. × 12 hours / cycle) × 100 cycles]>
For each film mirror, 10 cycles of 10 ° C. × 12 hours and 60 ° C. × 12 hours were repeated 100 cycles, and then each film mirror was visually observed from the hard coat layer side, and the degree of color change was evaluated in the same manner as described above.

From Table 1 above, the film mirrors 1 to 13 of the present invention in which the urethane-modified acrylic resin layer is disposed between the translucent resin layer and the resin base material are comparative examples 1 to 13 in which no urethane-modified acrylic resin layer is disposed. As compared with the film mirror 18 of Comparative Example 5 in which the film mirrors 14 to 17 and the acrylic resin layer (non-urethane modified acrylic resin layer) 4 are disposed, the haze increase and the reflectivity decrease under a high temperature environment. It can be seen that it can be significantly suppressed and prevented.

Furthermore, this application is based on Japanese Patent Application No. 2013-246333 filed on November 28, 2013, the disclosure of which is incorporated by reference in its entirety.

Claims

In order from the light incident side, a translucent resin layer containing an ultraviolet absorber, a urethane-modified acrylic resin layer, and a resin base material and a light reflecting layer, or
In order from the light incident side, a translucent resin layer containing an ultraviolet absorber, a urethane-modified acrylic resin layer, and a light reflecting layer and a resin base material,
A film mirror having at least.
The film mirror according to claim 1, further comprising a hard coat layer on a light incident side surface of the translucent resin layer.
The film mirror according to claim 2, wherein the hard coat layer is a metalloxane-based hard coat layer.
The film mirror according to any one of claims 1 to 3, wherein the translucent resin layer contains an ultraviolet absorber in an amount of 1 to 15% by mass in terms of solid content.
The urethane-modified acrylic resin has the following general formula (I):

Wherein R and R ′ each independently represents an alkylene group; m is an integer from 10 to 500; n is an integer from 10 to 500; and p is an integer from 10 to 200. The urethane / acrylic ratio (molar ratio) is 10/90 to 30/70,
The film mirror according to any one of claims 1 to 4, which is represented by:
6. The film mirror according to claim 1, wherein the urethane-modified acrylic resin layer has a thickness of 0.05 to 5 μm.