WO2015002053A1

WO2015002053A1 - Light reflecting film, and light reflecting body and light reflecting device using such light reflecting film

Info

Publication number: WO2015002053A1
Application number: PCT/JP2014/066902
Authority: WO
Inventors: 美佳本田
Original assignee: コニカミノルタ株式会社
Priority date: 2013-07-01
Filing date: 2014-06-25
Publication date: 2015-01-08
Also published as: JPWO2015002053A1

Abstract

[Problem] To provide a solar-light reflecting film that excels in efficient use of solar light, large surface-area production, and durability, and that is easy to manufacture. [Solution] This solar-light reflecting film has, in order from the light incident surface, an ultraviolet-ray reflecting laminate section formed by coating, and a silver reflecting layer, and the solar-light reflecting film is characterized in that at least one layer of the ultraviolet-ray reflecting laminate section includes at least one type of inorganic oxide.

Description

LIGHT REFLECTING FILM, LIGHT REFLECTOR AND LIGHT REFLECTION DEVICE USING THE SAME

The present invention relates to a light reflecting film capable of efficiently reflecting sunlight, and a light reflector and a light reflecting device using the same.

In recent years, global warming has become more serious, and the main cause is said to be carbon dioxide, a fossil fuel.

Power generation technology that uses natural energy such as sunlight, wind power, and geothermal heat is being developed as an alternative energy to fossil fuels. However, power generation using sunlight is particularly focused because of its abundance of stability and energy. Has been.

In solar thermal power generation, a condensing device that reflects sunlight by a reflector (mirror) and condenses it in one place is used. Since the reflector is exposed to ultraviolet rays, heat, wind and rain, and sandstorms caused by sunlight, a glass light reflector has been conventionally used from the viewpoint of durability. However, the light reflector made of glass has a problem that it is damaged during transportation, and because it is heavy, a high-strength gantry is required to install it, which increases the construction cost of the plant.

In order to solve the above problems, an attempt has been made to attach a resin light reflecting film with improved durability instead of a glass light reflecting member to a support and use it as a light reflecting member. For example, Patent Document 1 discloses a resinous highly reflective film including a silver reflective layer. In order to prevent deterioration of the resin due to ultraviolet rays, peeling damage, etc., and to overcome environmental resistance, the uppermost layer absorbs ultraviolet rays. By adopting a configuration including an ultraviolet shielding acrylic layer containing an agent, harmful ultraviolet rays are absorbed.

In order to use ultraviolet light energy for power generation, Patent Document 2 discloses a high refractive index as a means for reflecting ultraviolet light in order to reflect ultraviolet light in the same direction as visible light or infrared light and collect it in the light receiving unit. A technique is described in which an ultraviolet reflective layer is formed by laminating a refractive index material and a low refractive index material. Sunlight can be effectively reflected by the laminate reflecting ultraviolet to infrared.

Furthermore, Patent Document 3 describes an invention in which a metal plate made of aluminum or stainless steel is polished, and a multilayer reflective layer having a different refractive index is applied to the surface as a reflective coating.

Furthermore, as a means for forming a multilayer film, Patent Document 4 discloses an ultraviolet reflective layer characterized in that two types of polymer layers having different refractive indexes are alternately laminated, and heated and stretched near the glass transition point of the polymer. Has been proposed (see Comparative Example 4).

In Patent Document 5, a multilayer film that reflects ultraviolet rays is formed of a dielectric, while a silver thin film is used in the wavelength range of visible light and infrared light, and these two layers having different functions are combined. Thus, a method for efficiently reflecting sunlight is disclosed. Furthermore, the multilayer film reflecting ultraviolet rays has a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and the low refractive index layer includes a barrier layer having an oxygen barrier property and a water vapor barrier property. Also serves as. By adopting such a configuration, it is excellent in durability against sunlight degradation.

US Patent No. 7612937 European Patent Application No. 2204624 US Pat. No. 6,848,797 Special table 2011-521289 Japanese Patent No. 5424091

However, according to the technique of Patent Document 1, ultraviolet rays are absorbed by the ultraviolet absorber in the uppermost layer, so that the ultraviolet light energy cannot be used for power generation, and the efficient use of solar energy further increases the efficiency of power generation. It is insufficient in terms of improvement.

In addition, according to the technique of Patent Document 2, it is difficult to manufacture the ultraviolet reflecting layer by a method of forming a dense and elaborate film, except for sputtering under vacuum, which requires a long time for manufacturing, a large area and a large amount. There was a problem that production was difficult and impractical.

Furthermore, according to the technique of the above-mentioned Patent Document 3, aluminum and stainless steel are not so high in sunlight reflectivity, and in order to obtain a reflectivity close to 100%, the dependence on increased reflection is large. In addition, there is a problem that the cost increases when polishing an aluminum plate or a stainless steel plate over a large area.

Further, in the production method (technique) of Patent Document 4, an ultraviolet reflection layer can be produced in a large area and in a large amount. However, according to the technique of Patent Document 4, it is necessary to heat and stretch near the glass transition point of the polymer. . It was found that when the polymer was heated to near the glass transition temperature, radicals were generated, and the resulting ultraviolet reflective layer deteriorated with time. Therefore, when a multilayer ultraviolet reflective film formed by heating and stretching this polymer is exposed with a xenon lamp similar to sunlight, peeling of the layer interface occurs when irradiated with ultraviolet rays corresponding to 20 years of Phoenix, Arizona, USA. There was a problem that occurred. This is presumed that the radical generated at the time of manufacture caused deterioration.

Furthermore, in the technique of the above-mentioned Patent Document 5, in order to form a low refractive index layer that also serves as a barrier layer having an oxygen barrier property and a water vapor barrier property among the multilayer film reflecting ultraviolet rays, a film forming means such as plasma is used. Since a large amount of discharge power is required, manufacturing is not easy.

Accordingly, an object of the present invention is to provide a solar reflective film that is excellent in the efficient use of sunlight, large-area production, durability, and easy manufacture.

The present inventor conducted intensive research to solve the above problems. As a result, it is possible to produce a highly durable solar reflective film that can be produced in a large area using an ultraviolet reflective laminate that uses inorganic oxide and is laminated by coating a high refractive index material and a low refractive index material. The inventors have found that the above problems can be solved and the above object can be achieved, and the present invention has been completed.

That is, the solar reflective film of the present invention has, in order from the light incident surface, an ultraviolet reflective laminate formed by coating, and a silver reflective layer,
At least one layer of the ultraviolet reflective laminate includes at least one inorganic oxide.

It is sectional drawing which represents typically 1 form of the sunlight reflective film which concerns on embodiment of this invention. It is sectional drawing which represented typically the other form of the sunlight reflective film which concerns on embodiment of this invention. 4 is a cross-sectional view schematically showing a configuration of a sunlight reflecting film formed in Comparative Example 1. FIG. 3 is a cross-sectional view schematically showing the configuration of a sunlight reflecting film formed in Example 1. FIG. 4 is a cross-sectional view schematically showing the configuration of a sunlight reflecting film formed in Example 2. FIG. 6 is a cross-sectional view schematically showing a configuration of a sunlight reflecting film formed in Comparative Example 2. FIG. It is sectional drawing which represented typically the structure of the sunlight reflective film formed in the comparative example 3. FIG. 4 is a cross-sectional view schematically showing the configuration of a sunlight reflecting film formed in Example 3. FIG. It is sectional drawing which represented typically the structure of the sunlight reflective film formed in Example 4. FIG. It is sectional drawing which represented typically the structure of the sunlight reflective film formed in the comparative example 4. FIG. 10 is a cross-sectional view schematically showing the configuration of a sunlight reflecting film formed in Comparative Example 5. FIG. It is sectional drawing which represented typically the structure of the sunlight reflective film formed in the comparative example 6. FIG.

Hereinafter, preferred modes of the present invention will be described. However, the technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following modes.

<Sunlight reflection film>
Hereinafter, this embodiment will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

FIG. 1 is a cross-sectional view schematically showing one aspect of a sunlight reflecting film according to an embodiment of the present invention. A solar reflective film 10 shown in FIG. 1 includes, in order from the surface on which sunlight 100 is incident, an ultraviolet reflective laminated portion 11 formed by coating and a silver reflective layer 13, and includes at least the ultraviolet reflective laminated portion 11. One layer has a structure including at least one inorganic oxide 11a. According to the present invention having such a configuration, it is possible to provide a solar reflective film that is excellent in efficient use of sunlight, large-area production, durability, and easy to manufacture. Preferably, it is desirable that at least one of the two refractive index layers 111 and 112 having different refractive indexes constituting the ultraviolet reflecting laminated portion 11 has a structure including the inorganic oxide 11a. By setting it as this structure, the ultraviolet reflective lamination part 11 can reflect an ultraviolet-ray efficiently, without absorbing an ultraviolet-ray. Moreover, by reflecting the ultraviolet rays in the sunlight 100, deterioration of the lower layer material can be prevented and durability can be enhanced. Moreover, since the ultraviolet reflection laminated portion can be formed by coating, large area production can be performed in a short time. In addition, since the ultraviolet reflection laminated portion can be formed by coating, a process of exposing the ultraviolet reflective laminated portion to a high temperature such as heating and stretching near the glass transition point of the polymer (225 ° C.) as in Patent Document 4. This is excellent in that it can reduce deterioration factors and improve durability. Furthermore, since the ultraviolet reflection laminated portion can be formed by coating, the solar reflective film can be prevented from curling or greatly reduced. Furthermore, the vacuum reflective laminate (especially the low refractive index layer) can be formed by coating, so that vacuum deposition that requires a lot of electric power is required to form a low refractive index layer that also serves as a barrier layer as in Patent Document 5. Manufacturing can be easily performed without using film forming means such as sputtering, ion beam sputtering, CVD, and atmospheric pressure plasma.

In the solar reflective film 10, the sunlight 100 is incident on the silver reflective layer 13 side from the ultraviolet reflective laminated portion 11 side formed by coating containing the inorganic oxide 11a (without being heated and stretched) as indicated by an arrow. To do. Thus, in order from the direction in which the sunlight 100 is incident, the ultraviolet reflective laminate portion 11 including the inorganic oxide 11a and the silver reflective layer 13 are provided so that the ultraviolet rays can cause the inorganic oxide 11a of the solar reflective film 10 to pass through. It is possible to prevent the solar reflective film 10 from being deteriorated by preventing it from penetrating deeper than the ultraviolet reflective laminated portion 11 that is included.

In the solar reflective film 10, the ultraviolet reflection laminated portion 11 including the inorganic oxide 11 a has a unit in which a low refractive index layer 111 and a high refractive index layer 112 are laminated. As shown in FIG. 1, by laminating

layers

111 and 112 having different refractive indexes, light is reflected at the boundary surface, and an ultraviolet reflection function is exhibited. In FIG. 1, a multilayer of a high refractive index layer, a low refractive index layer,..., A high refractive index layer is laminated in order from the light incident direction as the ultraviolet reflecting laminated portion 11. Need only have at least one unit in which the low refractive index layer 111 and the high refractive index layer 112 are stacked, and the number of layers and the stacking order of the low refractive index layer 111 and the high refractive index layer 112 are not particularly limited. Further, in the embodiment shown in FIG. 1, the configuration in which the inorganic oxide 11a is included in all the low refractive index layers 111 and the high refractive index layers 112 constituting the ultraviolet reflective laminated portion 11 is shown. It is only necessary that the inorganic oxide 11 a is included in at least one of the layers constituting the reflective laminated portion 11. For example, Example 1 is a configuration example in which the inorganic oxide 112a (11a) is included only on the high refractive index layer 112 side. That is, as shown in Example 1, the inclusion of the inorganic oxide 112a (11a) on the high refractive index layer 112 side increases the refractive index difference (the refractive index difference between the low refractive index layer and the high refractive index layer). This is effective in increasing the ultraviolet reflection efficiency at the interface. In addition, the high refractive index layer 112 and the low refractive index layer 111 constituting the ultraviolet reflection laminated portion 11 both contain

inorganic oxides

112a and 111a as in this embodiment shown in FIG. As a result of the large refractive index difference of the refractive index layer 111 and the increased ultraviolet reflection efficiency, it is more effective in that the light resistance is further improved (the same applies to the embodiment of FIG. 2; see Examples 2 to 4).

In the solar reflective film 10, at least one of the low refractive index layer 111 or the high refractive index layer 112 constituting the ultraviolet reflective laminated portion 11 is made of a resin that is soluble in at least one of water or a solvent compatible with water. It is preferable to include. By including such a specific resin, it is possible to form a thin film at a low temperature of 100 ° C. or lower, and it is possible to prevent radicals from remaining in the polymer without being exposed to a high-temperature heating process during production. In addition, by including such a resin, there is an advantage that a coating method can be employed for forming the layer of the ultraviolet reflecting laminated portion 11 (without heating and stretching) by coating. Further, by adopting a coating method (without heating and stretching) for forming the layer of the ultraviolet reflecting laminated portion 11, large area production of the obtained laminated body (ultraviolet reflecting laminated portion 11) is performed in a short time. It is possible. In addition, by adopting a coating method in which the ultraviolet reflecting laminated portion is formed by coating, the ultraviolet reflecting laminated portion is heated and stretched near the glass transition point of the polymer (225 ° C.) as in Patent Document 4. Since there is no process to be exposed to high temperatures, deterioration factors can be reduced and durability can be improved. Furthermore, curling of the entire sunlight reflecting film 10 can be reduced. Further, by adopting a coating method for forming the layer of the ultraviolet reflecting laminated portion 11 by coating (without heating and stretching), as in Patent Document 5, vacuum deposition, sputtering, Since it is not necessary to use means such as ion beam sputtering, CVD, atmospheric pressure plasma, etc., manufacturing can be performed easily.

In the embodiment of the solar reflective film 10 shown in FIG. 1, a resin film support (polymer film) 12 is disposed between the ultraviolet reflective laminate 11 and the silver reflective layer 13. That is, the ultraviolet reflecting laminated portion 11 is formed on one side (light incident surface side) of the resin film-like support 12, and the silver reflecting layer 13 is formed on the other side of the resin film-like support 12.

Further, one or more corrosion prevention layers 14 are disposed on the silver reflection layer 13 in order to prevent corrosion of silver constituting the silver reflection layer 13. Further, an adhesive layer 15 is disposed on the corrosion prevention layer 14 for sticking to a supporting base material (a constituent member of a solar reflector; not shown). Further, a release material (release film, release paper, etc.) 16 is provided on the pressure-sensitive adhesive layer 15 so as to facilitate storage, transportation, and handling until sticking to the support substrate.

Further, in the embodiment of the sunlight reflecting film 10 shown in FIG. 1, the scratch-resistant layer 17 is disposed on the ultraviolet reflecting laminated portion 11 (light incident surface side). In the form of FIG. 1, the scratch-resistant layer 17 is disposed on the outermost surface of the sunlight reflecting film 10. By providing the scratch-resistant layer 17 as described above, the ultraviolet reflective laminated portion 11 can be protected from scratches and the like, and the durability of the solar reflective film 10 can be improved.

FIG. 2 is a cross-sectional view schematically showing another aspect of the solar reflective film according to the embodiment of the present invention. Also in the sunlight reflecting film 10 ′ shown in FIG. 2, in order from the surface on which sunlight 100 is incident, the ultraviolet reflecting laminated portion 11 and the silver reflecting layer 13 are included, and at least one layer of the ultraviolet reflecting laminated portion 11 includes: It has a structure including at least one inorganic oxide 11a. In FIG. 2, similarly to FIG. 1, a form in which the high refractive index layer 112 and the low refractive index layer 111 constituting the ultraviolet reflecting laminated portion 11 contain

inorganic oxides

112 a and 111 a is illustrated.

1 and 2 are formed in the order of the ultraviolet reflection laminated portion 11 and the silver reflective layer 13 from the light incident side, but the ultraviolet reflective laminated portion 11 and the silver reflective layer with respect to the resin film-like support 12 are formed. 13 (further, the corrosion prevention layer 14) has a different arrangement (configuration). FIG. 1 shows a configuration in which an ultraviolet reflective laminated portion 11 is formed on one surface of a resin film-like support 12 and a silver reflective layer 13 is formed on the other surface (Examples 1 and 2 have the same configuration). is there). On the other hand, FIG. 2 shows a configuration in which the silver reflective layer 13 and the ultraviolet reflective laminated portion 11 are formed in this order on one surface of the resin film-like support 12 (Examples 3 and 4 have the same configuration). 1 and 2 can effectively and effectively express the effects of the present invention from the evaluation results shown in Examples 1 to 4 in Table 1. A solar reflective film 10 'shown in FIG. 2 has the same configuration (arrangement) as FIG. 1 except that the solar reflective film 10 shown in FIG. Therefore, the same description as in FIG. 1 is repeated, and the description thereof is omitted.

As described above, the solar reflective film of the present invention is not limited to the form shown in FIGS. 1 and 2 and can take any configuration within the range satisfying the requirements of the present invention. . Hereinafter, each component of the solar reflective film 10, 10 'of the present embodiment will be described in detail.

[Ultraviolet reflective laminate 11]
The solar

reflective films

10, 10 ′ of this embodiment essentially have the ultraviolet reflective laminated portion 11 on the light incident surface side with respect to the silver reflective layer 13. The ultraviolet reflection laminated portion 11 has a function of reflecting at least a part of the wavelength (light) in the ultraviolet region (280 to 400 nm) included in sunlight, preferably 50% or more of the ultraviolet ray of 360 to 400 nm, preferably Has a function of reflecting 60% or more, more preferably 70% or more, and particularly preferably 80% or more. The reflectance in the ultraviolet region (280 to 400 nm) contained in sunlight can be measured with a spectrophotometer having an integrating sphere.

In addition, the ultraviolet light reflection laminated portion 11 provided on the light incident surface side is particularly visible light to infrared light so that sunlight (particularly visible light to light in the infrared region) can be reflected by the lower silver reflection layer 13. It is desirable to transmit the light in the area. From this point of view, the transmittance of light in the visible to infrared region (wavelength of 400 to 2500 nm) of the ultraviolet reflecting laminated portion 11 is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and particularly preferably. Is in the range of 80% or more. The transmittance at a wavelength of 400 to 2500 nm can be measured by a spectrophotometer having an integrating sphere.

The ultraviolet reflecting laminated portion 11 preferably has at least one unit in which the low refractive index layer 111 and the high refractive index layer 112 are laminated.

The ultraviolet reflecting laminated portion 11 has a form of an alternating laminated body in which low refractive index layers 111 and high refractive index layers 112 are alternately laminated. The ultraviolet reflection function is expressed by the difference in refractive index between the low refractive index layer 111 and the high refractive index layer 112. In the present specification, “low refractive index layer” and “high refractive index layer” mean that a refractive index layer having a lower refractive index is a low refractive index when the difference in refractive index between two adjacent layers is compared. This means that the higher refractive index layer is the higher refractive index layer.

The solar

reflective films

10 and 10 ′ of the present embodiment are used in at least one of water or a solvent in which at least one of the low refractive index layer 111 and the high refractive index layer 112 constituting the ultraviolet reflective laminated portion 11 is compatible with water. It is preferable to include a soluble resin 11b (111b to 112b). In this specification, “solvent having compatibility with water” means a solvent which does not form an interface when mixed with water and contains a hydroxyl group, a carbonyl group, a carboxyl group, an aldehyde group, etc. in the chemical structure. To do. In addition, “resin that is soluble in at least one of water or a solvent compatible with water” means that the resin does not precipitate after mixing with water or a solvent compatible with water and agitation and light scattering. Means a resin that is not visible. In other words, it is defined here as being compatible if it has a very small particle size, the same refractive index, and no white turbidity or light scattering when visually mixed and stirred. The resin 11b soluble in at least one of water or a solvent compatible with water may be contained in only one of the low refractive index layer 111 and the high refractive index layer 112 or in both. It doesn't matter. As long as at least one of the low refractive index layer 111 and the high refractive index layer 112 includes a resin that is soluble in at least one of water or a solvent compatible with water, the low refractive index layer 111 and / or the high refractive index layer 111 are used. Of course, the refractive index layer 112 may contain a resin that is insoluble in either water or a solvent compatible with water. Further, in the present specification, among “resins that are soluble in at least one of the low refractive index layer and the high refractive index layer in at least one of water or a solvent compatible with water”, “water soluble resin” Also referred to as “water-soluble resin”.

In the solar

reflective films

10, 10 ′ of this embodiment, the resin 11b is preferably excellent in light resistance, and specifically, is preferably a resin that does not contain an aromatic ring in the main chain. It is more preferable that the resin is composed of a monomer component that does not have any. Examples of such resins include water-soluble resins, silicone resins, acrylic resins, olefin resins, vinyl chloride resins, acrylic / urethane resins, and fluorine-containing polymers. Among the resins 11 soluble in at least one of these water or water-compatible solvents, it is preferable to use a water-soluble resin as will be described later, but among the resins other than the water-soluble resin, particularly weather resistance. As a material having excellent properties, a silicone resin having a siloxane bond or an acrylic copolymer obtained by copolymerizing at least two kinds of acrylic monomers is suitably used.

In the solar reflective film 10, 10 'of the present embodiment, the ultraviolet reflective laminated portion 11 (respective refractive index layers 111, 112) is formed by coating. The resin 11b is preferably a water-soluble resin from the viewpoint that aqueous coating can be used to form the ultraviolet reflecting laminated portion 11 (respective refractive index layers 111 and 112) by coating. By using water-based coating to form the ultraviolet reflecting laminated portion 11 by coating, dissolution of the coating layer with an organic solvent can be suppressed.

Examples of the water-soluble resin include polyvinyl alcohol (PVA), polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, or Acrylic resins such as acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene- Styrene acrylic resin such as acrylic acid copolymer or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrene sulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer , Styrene-2-hydroxye Tyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-maleic Synthetic water-soluble resins such as acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and their salts; gelatin, thickening polysaccharides, etc. Examples include natural water-soluble resins. Of these, polyvinyl alcohols, copolymers containing the same, gelatin, and thickening polysaccharides (particularly celluloses) are preferable from the viewpoint of handling during production and film flexibility, and in particular, from the viewpoint of optical properties. To polyvinyl alcohols. These water-soluble resins may be used alone or in combination of two or more.

As the polyvinyl alcohols used in this embodiment, modified polyvinyl alcohol partially modified can be used in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate. Unless otherwise specified, “ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate” is also simply referred to as “polyvinyl alcohol” unless otherwise specified. In the solar reflective film 10 of this embodiment, when both the low refractive index layer 111 and the high refractive index layer 112 contain at least one polyvinyl alcohol, the polyvinyl alcohol having the highest content in the low refractive index layer 111. Is the polyvinyl alcohol (A), and the polyvinyl alcohol (B) is the polyvinyl alcohol (B) having the highest content in the high refractive index layer 112, the saponification degree of the polyvinyl alcohol (A) and the saponification of the polyvinyl alcohol (B) The degree is preferably different. Here, the degree of saponification is the ratio of hydroxyl groups to the total number of acetyloxy groups (derived from the starting vinyl acetate) and hydroxyl groups in polyvinyl alcohol. By using polyvinyl alcohol having different saponification degrees as described above, the interlayer mixing between the high refractive index layer 112 and the low refractive index layer 111 is small, and a high reflectance can be obtained. Specifically, interfacial mixing when the refractive index layers 111 and 112 are formed by water-based multilayer coating is suppressed, and interface disturbance is reduced, so that UV reflection with a desired wavelength is excellent and UV reflection with less haze is achieved. The stacked portion 11 can be formed.

The polyvinyl alcohol for comparing the difference in saponification degree in each of the refractive index layers 111 and 112 is a case where each refractive index layer contains a plurality of polyvinyl alcohols (that is, two or more kinds of polyvinyl alcohols having different saponification degrees or polymerization degrees). ) Is polyvinyl alcohol having the highest content in the refractive index layer. Here, when “polyvinyl alcohol having the highest content in the refractive index layer” is referred to, the degree of polymerization is calculated assuming that the polyvinyl alcohol having a difference in saponification degree of 3 mol% or less is the same polyvinyl alcohol. However, a low polymerization degree polyvinyl alcohol having a polymerization degree of 1000 or less is a different polyvinyl alcohol (if the difference in saponification degree is 3 mol% or less, the same polyvinyl alcohol is not used). Specifically, when polyvinyl alcohol having a saponification degree of 90 mol%, a saponification degree of 91 mol%, and a saponification degree of 93 mol% is contained in the same layer by 10 mass%, 40 mass%, and 50 mass%, respectively, these 3 The two polyvinyl alcohols are the same polyvinyl alcohol, and the mixture of these three is polyvinyl alcohol (A) or (B). Further, the above-mentioned “polyvinyl alcohol having a saponification degree difference of 3 mol% or less” is sufficient if it is within 3 mol% when attention is paid to any polyvinyl alcohol, for example, 90, 91, 92, 94 mol% vinyl alcohol. In the case of containing 91 mol% of vinyl alcohol, since any polyvinyl alcohol is within 3 mol% when focusing on 91 mol% of vinyl alcohol, the same polyvinyl alcohol is obtained.

In this embodiment, when the polyvinyl alcohol having the highest content is composed of a plurality of polyvinyl alcohol species having a saponification degree difference of 3 mol% or less, the polyvinyl alcohol having the highest content has the highest polyvinyl alcohol content. The sum is obtained by multiplying the saponification degree of each polyvinyl alcohol constituting the alcohol by the content of the polyvinyl alcohol. Specifically, it is calculated as follows. Polyvinyl alcohol having the highest content is composed of polyvinyl alcohol (1) and polyvinyl alcohol (2). Polyvinyl alcohol (1) (content of polyvinyl alcohol (1) with respect to the total amount (solid content) of the refractive index layer: Wa, saponification Degree: Sa (mol%)) and polyvinyl alcohol (2) (content of polyvinyl alcohol (2) with respect to the total amount (solid content) of the refractive index layer: Wb, saponification degree: Sb (mol%)) The highest saponification degree of polyvinyl alcohol is as shown in the following formula.

When different polyvinyl alcohols having a saponification degree exceeding 3 mol% are contained in one layer, they are regarded as a mixture of different polyvinyl alcohols, and the polymerization degree and the saponification degree are calculated for each. For example, PVA103: 5% by mass, PVA117: 25% by mass, PVA217: 10% by mass, PVA220: 10% by mass, PVA224: 10% by mass, PVA235: 20% by mass, PVA245: 20% by mass, most contained PVA having a large amount is a mixture of PVA 217 to 245 (the difference in the degree of saponification of PVA 217 to 245 is within 3 mol%, and thus is the same polyvinyl alcohol. Here, PVA103 to PVA245 are all trade names of Kuraray Co., Ltd. ( Kuraraypoval = PVA) and brands (103 to 245). The numbers at the beginning of the brand represent the classification of the degree of saponification, and the next two numbers multiplied by 100 represent the degree of polymerization. First number 1 = degree of saponification 98-99 mol%, average value 98.5 mol%, initial number 2 of brands = The degree of conversion is 87 to 89 mol% and the average value is 88 mol%, and the following two numbers are, for example, 03 = degree of polymerization 300, 17 = degree of polymerization 1700, 45 = degree of polymerization 4500). This mixture becomes polyvinyl alcohol (A) or (B). In the mixture of PVA 217 to 245 (polyvinyl alcohol (A) / (B)), the degree of polymerization is (1700 × 0.1 + 2000 × 0.1 + 2400 × 0.1 + 3500 × 0.2 + 4500 × 0.2) / 0. .7 = 3200, and the degree of saponification is 88 mol%.

Further, when a plurality of polyvinyl alcohol (group) having the highest content is present at the same content, the combination of any one of the polyvinyl alcohol (group) is obtained by combining the low refractive index layer 111 and the high refractive index layer 112. The degree of saponification may be different. For example, in the low refractive index layer 111, polyvinyl alcohol (1) (degree of saponification 98.5 mol%): 20% by mass, polyvinyl alcohol (2) (degree of saponification 88 mol%): 20% by mass, polyvinyl alcohol as polyvinyl alcohol. (3) (Saponification degree: 79.5 mol%): 20% by mass (when a plurality of polyvinyl alcohols (group) having the highest content are present in the same content), polyvinyl alcohol (1) Any one of (2) and (3) may be different from the saponification degree of the polyvinyl alcohol (B) having the highest content contained in the high refractive index layer 112.

The difference in the absolute value of the saponification degree between the polyvinyl alcohol (A) and the polyvinyl alcohol (B) is preferably 1 mol% or more, and more preferably 3 mol% or more. More preferably, it is 5 mol% or more. Further, it is more preferably 8 mol% or more, and most preferably 10 mol% or more. If it is such a range, it is preferable in order to make the interlayer mixing state of the low refractive index layer 111 and the high refractive index layer 112 into a preferable level. The difference in the degree of saponification between the polyvinyl alcohol (A) and the polyvinyl alcohol (B) is preferably as far as possible, but is preferably 20 mol% or less from the viewpoint of the solubility of polyvinyl alcohol in water.

The saponification degree of polyvinyl alcohol (A) and polyvinyl alcohol (B) is preferably 75 mol% or more from the viewpoint of solubility in water. Furthermore, it is preferable that one of the polyvinyl alcohol (A) and the polyvinyl alcohol (B) has a saponification degree of 90 mol% or more, and the other has a saponification degree lower than that of polyvinyl alcohol having a saponification degree of 90 mol% or more. In such a form, interlayer mixing is further suppressed. Further, one of the polyvinyl alcohol (A) and the polyvinyl alcohol (B) has a saponification degree of 90 mol% or more and the other has a ratio of 90 mol% or less, which is an interlayer mixed state of the low refractive index layer 111 and the high refractive index layer 112. Is preferable because the reflectance of a specific wavelength (ultraviolet ray) is improved. One of the polyvinyl alcohol (A) and the polyvinyl alcohol (B) has a saponification degree of 95 mol% or more, and the other is preferably 90 mol% or less from the viewpoint of improving the reflectance at a specific wavelength (ultraviolet light). In addition, although the upper limit of the saponification degree of polyvinyl alcohol is not specifically limited, Usually, it is less than 100 mol% and is about 99.9 mol% or less.

Further, the polymerization degree of the two types of polyvinyl alcohols having different saponification degrees is preferably 1000 or more, particularly preferably having an average polymerization degree of 1500 to 5000, and more preferably 2000 to 5000. When the polymerization degree of polyvinyl alcohol is 1000 or more, the coating film is not cracked, and when it is 5000 or less, handling properties are good and work efficiency is improved, which is preferable. Further, when the degree of polymerization of at least one of polyvinyl alcohol (A) and polyvinyl alcohol (B) is 2000 to 5000, it is preferable because cracks of the coating film are reduced and the reflectance at a specific wavelength (ultraviolet ray) is improved. It is preferable that the degree of polymerization of both polyvinyl alcohol (A) and polyvinyl alcohol (B) is 2000 to 5000 because the layers are further separated and the above effects are more prominently exhibited. Here, the degree of polymerization refers to the viscosity average degree of polymerization, and is measured according to JIS-K6726 (1994). Specifically, after the polyvinyl alcohol is completely re-saponified and purified, it is obtained from the intrinsic viscosity [η] (dl / g) measured in water at 30 ° C. by the following formula.

In this embodiment, the polyvinyl alcohol (A) and the polyvinyl alcohol (B) are preferably contained in a range of 5.0% by mass or more, more preferably 10% by mass or more with respect to the total mass of each refractive index layer. It is preferable. When the content is 5.0% by mass or more, the effect that inter-layer mixing is suppressed and the disturbance of the interface is reduced appears significantly. Moreover, 50 mass% or less is preferable with respect to the total mass of each refractive index layer, and, as for polyvinyl alcohol (A) and polyvinyl alcohol (B), 40 mass% or less is more preferable. If the content is 50% by mass or less, the content of the relative inorganic oxide (111a, 112a) is appropriate, and the difference in refractive index between the low refractive index layer 111 and the high refractive index layer 112 may be increased. It becomes easy.

In this embodiment, in addition to the two types of polyvinyl alcohols having different saponification degrees, the polymerization degree is 100 to 1000, more preferably, the polymerization degree is 100 to 500, and the saponification degree is 95 mol% or more. It is preferable that at least one of the respective refractive index layers contains (also simply referred to as a low polymerization degree, highly saponified polyvinyl alcohol). When such a low degree of polymerization and high saponified polyvinyl alcohol is contained, the stability of the coating solution is improved. More preferably, both refractive index layers contain a low degree of polymerization and a highly saponified polyvinyl alcohol from the viewpoint of the stability of the coating solution. The content of the saponified polyvinyl alcohol having a low polymerization degree is not particularly limited, but is preferably 0.5 to 5% by mass with respect to the total mass (solid content) of each refractive index layer. If it is such a range, the said effect will be exhibited more. The upper limit of the saponification degree of the low polymerization degree and high saponification polyvinyl alcohol is not particularly limited, but is usually less than 100 mol% and about 99.9 mol% or less.

In this embodiment, in addition to the two types of polyvinyl alcohols (polyvinyl alcohol (A) and polyvinyl alcohol (B)) having different saponification degrees, either the low refractive index layer 111 or the high refractive index layer 112 has a saponification degree of 90 mol%. It is preferable to further contain the above (more preferably 95 mol% or more) polyvinyl alcohol. By containing such a high saponification degree polyvinyl alcohol, the coating solution is stabilized, inter-layer mixing is further suppressed, and the reflectance is further improved.

Further, each refractive index layer may contain modified polyvinyl alcohol partially modified in addition to normal polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate. When such modified polyvinyl alcohol is contained, the adhesion, water resistance, and flexibility of the film (each refractive index layer) may be improved. Examples of such modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonionic-modified polyvinyl alcohol, and vinyl alcohol polymers. These modified polyvinyl alcohols can be used in combination of two or more types having different degrees of polymerization and modification.

Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups in the main chain or side chain of the polyvinyl alcohol as described in, for example, JP-A-61-110483. It is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride. N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride, trimethyl- (2-methacrylamidopropyl) ammonium chloride, N- (1, And 1-dimethyl-3-dimethylaminopropyl) acrylamide. The ratio of the cation-modified group-containing monomer in the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol%, relative to vinyl acetate.

Anion-modified polyvinyl alcohol is described in, for example, polyvinyl alcohol having an anionic group as described in JP-A-1-206088, JP-A-61-237681 and JP-A-63-307979. Examples thereof include a copolymer of vinyl alcohol and a vinyl compound having a water-soluble group, and a modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

Nonionic modified polyvinyl alcohol is, for example, a polyvinyl alcohol derivative obtained by adding a polyalkylene oxide group to a part of vinyl alcohol as described in JP-A-7-9758, and described in JP-A-8-25795. Block copolymer of a vinyl compound having a hydrophobic group and vinyl alcohol, a silanol-modified polyvinyl alcohol having a silanol group, a reactive group-modified polyvinyl alcohol having a reactive group such as an acetoacetyl group, a carbonyl group or a carboxyl group Etc.

Examples of vinyl alcohol polymers include EXEVAL (trade name: manufactured by Kuraray Co., Ltd.) and Nichigo G polymer (trade name: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

The content of the modified polyvinyl alcohol is not particularly limited, but is preferably 1 to 30% by mass with respect to the total mass (solid content) of each refractive index layer. If it is such a range, the adhesiveness of said film | membrane, water resistance, and the improvement effect of a softness | flexibility will be exhibited more.

In this embodiment, the two types of polyvinyl alcohol having different saponification degrees may be contained in a range of 40% by mass to 100% by mass with respect to the total mass of the total polyvinyl alcohol and the modified polyvinyl alcohol in the refractive index layer. 60 mass% or more and 95 mass% or less are more preferable. When the content is 40% by mass or more, the effect that inter-layer mixing is suppressed and the turbulence of the interface is reduced is remarkably exhibited. On the other hand, if content is 95 mass% or less, stability of a coating liquid will improve.

As the gelatin, in addition to lime-processed gelatin, acid-processed gelatin may be used, and gelatin hydrolyzate and gelatin enzyme-decomposed product can also be used.

Examples of thickening polysaccharides include generally known natural simple polysaccharides, natural complex polysaccharides, synthetic simple polysaccharides, and synthetic complex polysaccharides. For details on these polysaccharides, see “Biochemistry”. Reference can be made to the encyclopedia (2nd edition), Tokyo Kagaku Doujin Publishing, “Food Industry”, Vol. 31 (1988), p. 21. In the present specification, the thickening polysaccharide is a saccharide polymer having a large number of hydrogen bonding groups in the molecule. It refers to a polysaccharide with characteristics that have a large difference from the viscosity of time. Furthermore, when the inorganic oxide particles 111a to 112a are added, a viscosity increase caused by hydrogen bonding with the inorganic oxide particles 111a to 112a occurs at a low temperature. The polysaccharide is preferably a polysaccharide that causes an increase of 1.0 mPa · s or more, more preferably 5.0 mPa · s or more, and still more preferably a polysaccharide having a viscosity increasing ability of 10.0 mPa · s or more.

Examples of such thickening polysaccharides include β1-4 glucan (eg, carboxymethylcellulose, carboxyethylcellulose, etc.), galactan (eg, agarose, agaropectin, etc.), galactomannoglycan (eg, locust bean gum, guaran, etc.). ), Xyloglucan (eg, tamarind gum, etc.), glucomannoglycan (eg, salmon mannan, wood-derived glucomannan, xanthan gum, etc.), galactoglucomannoglycan (eg, softwood-derived glycan), arabinogalactoglycan ( For example, soybean-derived glycans, microbial-derived glycans, etc.), glucoraminoglycans (eg, gellan gum), glycosaminoglycans (eg, hyaluronic acid, keratan sulfate, etc.), alginic acid and alginate, agar, κ-ca Examples thereof include natural high molecular polysaccharides derived from red algae such as laginan, λ-carrageenan, ι-carrageenan, and far cerulean.

The weight average molecular weight of the water-soluble resin is not particularly limited, but is preferably from 1,000 to 200,000, more preferably from 3,000 to 40,000, from the viewpoint of production by adjusting the viscosity to be coatable. In this specification, the value measured on the following measurement conditions using gel permeation chromatography (GPC) is employ | adopted for a weight average molecular weight.

Solvent: 0.2M NaNOH ₃ , NaH ₂ P0 ₄ , pH 7
・ Column: Combination of Shodex Column Ohpak SB-802.5 HQ, 8 × 300 mm and Shodex Column Ohpak SB-805 HQ, 8 × 300 mm ・ Column temperature: 45 ° C.
Sample concentration: 0.1% by mass
・ Detector: RID-10A (manufactured by Shimadzu Corporation)
・ Pump: LC-20AD (manufactured by Shimadzu Corporation)
・ Flow rate: 1 ml / min
・ Calibration curve: Standard P-82 standard substance pullulan calibration curve for Shodex standard GFC (aqueous GPC) column is used.

In this embodiment, a curing agent for curing the water-soluble resin may be used. The kind of the curing agent is not particularly limited, and any curing agent can be used as long as it causes a curing reaction with the water-soluble resin.

Examples of the curing agent when the water-soluble resin is polyvinyl alcohol include boric acid having a boron atom, borate, and borax. When these are used, more excellent ultraviolet reflection characteristics can be exhibited. In particular, after applying a multi-layered multilayer of a low refractive index layer 111 and a high refractive index layer 112 with a coater, the film surface temperature of the coating film was once cooled to about 15 ° C. and then the film surface was dried. In some cases, the effect can be expressed more preferably.

Boric acid or borate refers to oxyacids and salts thereof having a boron atom as a central atom. Specifically, orthoboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid and octaboric acid are used. Examples include boric acid and salts thereof.

Borax is a mineral represented by Na ₂ B ₄ O ₅ (OH) ₄ .8H ₂ O (decahydrate of sodium tetraborate Na ₂ B ₄ O ₇ ).

Boric acid, borate, and borax may be used alone or in combination of two or more.

In addition to this, a compound having a group capable of reacting with polyvinyl alcohol or a compound that accelerates the reaction between different groups of polyvinyl alcohol is suitably used as the curing agent. Specific examples include epoxy curing agents, active halogen curing agents, active vinyl compounds, and aluminum alum.

The total amount of the curing agent used is preferably 1 to 600 mg, more preferably 100 to 500 mg, per gram of polyvinyl alcohol resin.

Examples of the hardener when the water-soluble resin is gelatin include organic hardeners such as vinyl sulfone compounds, urea-formalin condensates, melanin-formalin condensates, epoxy compounds, aziridine compounds, active olefins, and isocyanate compounds. Examples of the film agent include inorganic polyvalent metal salts such as chromium, aluminum, and zirconium.

Of the resins other than water-soluble resins, silicone resins include, for example, trimethoxysilane (Kanto Chemical), Solguard NP-730 (Nippon Dacro Shamrock), Tosgard 510 (Toshiba Silicone), KP-64 (Shin-Etsu Chemical). ) Etc. can be employed. The main component of such a silicone resin is represented by RXSi (OR ') 4-X, where R and R' are organic groups such as methyl and ethyl groups, and X is 0 and a natural number.

Examples of acrylic resins include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl methacrylate. The main component is one or two or more monomers selected from monomers having no functional group in the side chain such as alkyl (meth) acrylate such as non-functional monomers (hereinafter referred to as non-functional monomers). OH is present in the side chain of one or more monomers selected from monomers such as hydroxyethyl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, and itaconic acid. Copolymers such as a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, and a bulk polymerization method are used in combination of one or more monomers having a functional group such as COOH (hereinafter referred to as functional monomers). Examples thereof include acrylic copolymers having a weight average molecular weight of 40,000 to 1,000,000, preferably 100,000 to 400,000, obtained by polymerization. Among them, 50 to 90% by mass of a non-functional monomer that gives a polymer having a relatively low glass transition point (Tg) such as ethyl acrylate, methyl acrylate, and 2-ethylhexyl methacrylate, and a comparison of methyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, etc. An acrylic polymer containing 10 to 50% by mass of a non-functional monomer that gives a polymer having a high Tg and 0 to 10% by mass of a functional monomer such as 2-hydroxyethyl methacrylate, acrylic acid, and itaconic acid is the most. Is preferred. Commercially available acrylic resins may also be used. For example, BR-85 manufactured by Mitsubishi Rayon, Delpet SRB215 manufactured by Asahi Kasei Chemicals, etc. may be used.

The cycloolefin resin is a polymer resin containing an alicyclic structure. A preferred cycloolefin resin is a resin obtained by polymerizing or copolymerizing a cyclic olefin. Examples of the cyclic olefin include norbornene, dicyclopentadiene, tetracyclododecene, ethyltetracyclododecene, ethylidenetetracyclododecene, and tetracyclo [7.4.0.110, 13.02,7] trideca-2,4. Unsaturated hydrocarbons having a polycyclic structure such as 6,11-tetraene and derivatives thereof, cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclo Examples thereof include monocyclic unsaturated hydrocarbons such as octene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene, cycloheptene, cyclopentadiene, cyclohexadiene, and derivatives thereof. Preferred cycloolefin resins may be those obtained by addition copolymerization of monomers other than cyclic olefins. Examples of addition copolymerizable monomers include ethylene such as ethylene, propylene, 1-butene and 1-pentene, or α-olefin, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl- Examples include dienes such as 1,4-hexadiene and 1,7-octadiene. It is not limited to these. Moreover, these may be used individually by 1 type and may be used in combination of 2 or more type. Specifically, ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, APPEL manufactured by Mitsui Chemicals, Inc. (APL8008T, APL6509T, APL6013T, APL5014DP, APL6015T) and the like are preferably used.

Examples of vinyl chloride resins include vinyl chloride homopolymer (vinyl chloride homopolymer), a copolymer of a monomer having an unsaturated bond copolymerizable with vinyl chloride monomer and vinyl chloride monomer, and vinyl chloride monomer in the polymer. Examples thereof include graft copolymers obtained by graft copolymerization, and (co) polymers composed of chlorinated vinyl chloride monomer units. These may be used alone or in combination of two or more.

The acrylic / urethane resin can be used without limitation as long as it can be obtained by reacting a polyvalent isocyanate compound or polyurethane having an isocyanate group with an acrylic monomer. Examples of acrylic monomers include alkyl acrylates (methyl groups such as methyl, ethyl, n-propyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.), alkyl methacrylates (methyl as the alkyl group, Hydroxy such as ethyl, n-propyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.), 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, etc. Group-containing monomers, acrylamide, methacrylamide, N-methyl methacrylamide, N-methyl acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, N-dimethyl Amide group-containing monomers such as acrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-butoxymethylacrylamide, N-phenylacrylamide, N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, etc. Amino group-containing monomers, glycidyl group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, monomers containing a carboxyl group such as acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) or salts thereof, etc. Can be used. It is preferable to copolymerize a crosslinkable functional group, and it is particularly preferable to copolymerize N-methylolacrylamide in terms of improving self-crosslinking property and crosslinking density. The copolymerization ratio of N-methylolacrylamide is preferably 0.5 to 5% by weight from the viewpoint of copolymerizability and the degree of crosslinking, and more preferably 1 to 3% by weight in view of the coating appearance. Examples of the crosslinking agent include melamine crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolized or alkylolized urea, acrylamide, polyamide resin, oxazoline crosslinking agent, and carbodiimide. Cross-linking agents, various silane coupling agents, various titanate coupling agents and the like can be used. It is preferable that at least one of the crosslinking agents contains an oxazoline-based crosslinking agent and a carbodiimide-based crosslinking agent.

Examples of the fluorine-containing polymer include a polymer mainly containing a fluorine-containing unsaturated ethylenic monomer component.

Examples of the fluorine-containing unsaturated ethylenic monomer include a fluorine-containing alkene, a fluorine-containing acrylic acid ester, a fluorine-containing methacrylate ester, a fluorine-containing vinyl ester, a fluorine-containing vinyl ether, and the like. And fluorine-containing unsaturated ethylenic monomers described in paragraph “0181” of the No.

Examples of monomers that can be copolymerized with fluorine-containing monomers include, for example, ethylene, propylene, butene, vinyl acetate, vinyl ethyl ether, vinyl ethyl ketone, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, Ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl-α-fluoroacrylate, ethyl-α-fluoroacrylate, propyl-α-fluoroacrylate, butyl-α-fluoroacrylate, acrylic acid, methacrylic acid, α-fluoroacrylic acid, styrene Styrene sulfonic acid, methoxypolyethylene glycol methacrylate and the like.

The refractive index of a single resin of a fluorine-containing ethylenically unsaturated monomer is in the range of approximately 1.33 to 1.42, and the refractive index of a single resin polymer of a fluorine-free monomer that can be copolymerized. Can be used as a fluorine-containing polymer having a desired refractive index by copolymerizing these at an arbitrary ratio of 1.44 or more, and having a desired refractive index by mixing with the polyvinyl alcohol at an arbitrary ratio. Can be used. The content ratio (in terms of solid content) in the refractive index layer of such a fluoropolymer and polyvinyl alcohol is preferably polyvinyl alcohol: fluoropolymer = 1: 0.1-5.

When the refractive index layer does not contain an inorganic oxide (111a to 112a), the solid content in each refractive index layer is from the viewpoint of viscosity adjustment during coating. The total amount is preferably 50 to 100% by mass, more preferably 80 to 100% by mass. If it is 50 mass% or more, layer formation is possible. On the other hand, the content of the resin in each refractive index layer is 30 to the total solid content in each refractive index layer when each refractive index layer contains an inorganic oxide (111a to 112a). It is preferably 70% by mass, and preferably 40-50% by mass. Even when the inorganic oxide (111a to 112a) is contained, the layer can be formed if the resin content is 30% by mass or more.

(Inorganic oxide 11a (111a to 112a)
At least one layer of the ultraviolet reflecting portion 11 in the

sunlight reflecting films

10, 10 ′ of the present embodiment includes at least one inorganic oxide 11a. By setting it as this structure, the ultraviolet-ray reflection lamination | stacking part 11 reflects an ultraviolet-ray efficiently, and the efficient utilization of sunlight is achieved. Moreover, by reflecting the ultraviolet rays, deterioration of the lower layer material can be prevented and durability can be enhanced. In particular, the inorganic oxide 11a can increase the refractive index of the layer (refractive index layer) containing the inorganic oxide 11a. Moreover, it is excellent at the point which can adjust the viscosity of the coating liquid (refractive index layer coating liquid) used for formation of the layer (refractive index layer) containing the inorganic oxide 11a. Preferably, at least one of the low-refractive index layer 111 or the high-refractive index layer 112 constituting the ultraviolet ray reflecting section 11 preferably includes the inorganic oxide 11a (111a to 112a) and the resin 11b described above. Further, at least one of the low refractive index layer 111 and the high refractive index layer 112 is preferably formed by applying a solution containing the inorganic oxide 11a (111a to 112a) and a resin component, respectively. Thereby, since the ultraviolet reflective laminated part 11 can be formed by coating, large area production can be performed in a short time.

The inorganic oxide particles 11a preferably have an average particle size of 100 nm or less so as to be suitable for ultraviolet reflection. When the average particle diameter of the inorganic oxide particles to be used is 100 nm or less, light scattering can be suppressed and the accuracy in controlling the film thickness of each refractive index layer in the ultraviolet reflective film can be improved. Here, in this specification, an average particle diameter refers to a primary average particle diameter. As used herein, the primary average particle size refers to a method of observing the particles themselves using a laser diffraction scattering method, a dynamic light scattering method, or an electron microscope, or a cross section or surface of the refractive index layer (111, 112). The average particle size is a value obtained by measuring the particle size of 1000 arbitrary particles by a method of observing the appearing particle image with an electron microscope. When the inorganic oxide particles 11a are coated (for example, a silica-attached titanium dioxide sol described later), the average particle diameter of the inorganic oxide particles 11a is the matrix (the silica described above). In the case of an attached titanium dioxide sol, it means the average particle diameter of titanium dioxide before treatment). In this embodiment, the inorganic oxide 111a (for example, colloidal silica particles) in the low refractive index layer 111 functions as a low refractive index material, and the inorganic oxide 112a (for example, titanium oxide particles in the high refractive index layer 112). Etc.) function as a high refractive index material.

(Inorganic oxide 111a in the low refractive index layer 111)
In the low refractive index layer 111, silica (silicon dioxide) is preferably used as the inorganic oxide 111a, and specific examples include synthetic amorphous silica and colloidal silica. Among these, it is more preferable to use acidic colloidal silica sol, and it is particularly preferable to use colloidal silica dispersed in an organic solvent. In order to further reduce the refractive index, hollow fine particles having pores inside the particles may be used as the inorganic oxide fine particles 111a of the low refractive index layer 111. In particular, hollow fine particles of silica (silicon dioxide) may be used. preferable. Moreover, well-known inorganic oxide particles other than a silica can also be used. In the low refractive index layer 111, as the inorganic oxide 111a, it is preferable to use silicon dioxide from the viewpoint of a low refractive index and a small particle size, and a low refractive index, a small particle size, and high transparency. From the viewpoint of easy handling without forming secondary particles, it is particularly preferable to use colloidal silica.

The inorganic oxide particles 111a (preferably silicon dioxide) contained in the low refractive index layer 111 preferably have an average particle size of 3 to 100 nm. The average particle diameter of primary particles of silicon dioxide dispersed in a primary particle state (particle diameter in a dispersion state before coating) is more preferably 3 to 50 nm, and further preferably 3 to 40 nm. It is particularly preferably 3 to 20 nm, and most preferably 4 to 10 nm. Moreover, as an average particle diameter of secondary particle | grains, it is preferable from a viewpoint with few hazes and excellent visible light transmittance | permeability that it is 30 nm or less.

The colloidal silica used in the present embodiment is obtained by heating and aging a silica sol obtained by metathesis with an acid of sodium silicate or the like and passing through an ion exchange resin layer. For example, JP-A-57-14091, JP-A-60-219083 and the like.

Such colloidal silica may be a synthetic product or a commercially available product. Examples of commercially available products include the Snowtex series (Snowtex OS, OXS, S, OS, 20, 30, 40, O, N, C, etc.) sold by Nissan Chemical Industries.

The surface of the colloidal silica may be cation-modified, or may be treated with Al, Ca, Mg, Ba or the like.

Moreover, hollow particles can also be used as the inorganic oxide particles 111 a of the low refractive index layer 111. When hollow fine particles are used, the average particle pore size is preferably 3 to 70 nm, more preferably 5 to 50 nm, and even more preferably 5 to 45 nm. The average particle pore size of the hollow fine particles is an average value of the inner diameters of the hollow fine particles. If the average particle pore diameter of the hollow fine particles is within the above range, the refractive index of the low refractive index layer is sufficiently lowered. The average particle diameter is 50 or more at random, which can be observed as an ellipse in a circular, elliptical or substantially circular shape by electron microscope observation, and obtains the pore diameter of each particle. Is obtained. The average particle hole diameter means the minimum distance among the distances between the two parallel lines that surround the outer edge of the hole diameter that can be observed as a circle, an ellipse, or a substantially circle or ellipse.

The content of the inorganic oxide particles 111a in the low refractive index layer 111 is preferably 20 to 90% by mass and preferably 30 to 85% by mass with respect to 100% by mass of the solid content of the low refractive index layer. More preferred is 40 to 70% by mass. When it is 20% by mass or more, a desired refractive index is obtained, and when it is 90% by mass or less, the coatability is good, which is preferable.

(Inorganic oxide 112a in the high refractive index layer 112)
As the inorganic oxide particles 112a of the high refractive index layer 112 according to this embodiment, for example, titanium dioxide, zirconium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, Examples thereof include ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon, and tin oxide. Among these, inorganic oxide particles 112a such as titanium dioxide and zirconium oxide that can form a transparent and higher refractive index layer 112 having a higher refractive index are preferable.

As titanium dioxide, rutile type (tetragonal) titanium oxide particles are preferable.

The primary average particle diameter of the inorganic oxide particles 112a used in the inorganic oxide particles 112a used in the high refractive index layer 112 is preferably 30 nm or less, more preferably 1 to 30 nm, and more preferably 5 to 15 nm. More preferably it is. A primary average particle diameter of 1 nm or more and 30 nm or less is preferable from the viewpoint of low haze and excellent visible light transmittance.

As the titanium oxide particles of this embodiment, it is preferable to use particles in which the surface of an aqueous titanium oxide sol is modified to stabilize the dispersion state.

Further, particles having a core-shell structure in which titanium oxide particles are coated with a silicon-containing hydrated oxide may be used. Here, the “coating” means a state in which a silicon-containing hydrated oxide is attached to at least a part of the surface of the titanium oxide particles. That is, the surface of the titanium oxide particles used as the inorganic oxide particles 112a may be completely covered with a silicon-containing hydrated oxide, and a part of the surface of the titanium oxide particles is a silicon-containing hydrated oxide. It may be covered with. From the viewpoint that the refractive index of the coated titanium oxide particles is controlled by the coating amount of the silicon-containing hydrated oxide, it is preferable that a part of the surface of the titanium oxide particles is coated with the silicon-containing hydrated oxide. . Hereinafter, such coated titanium oxide particles are also referred to as “silica-attached titanium dioxide sol”.

The titanium oxide of the titanium oxide particles coated with the silicon-containing hydrated oxide may be a rutile type or an anatase type, but a rutile type is more preferable. This is because the rutile type titanium oxide particles have lower photocatalytic activity than the anatase type titanium oxide particles, so that the weather resistance of the high refractive index layer 112 and the adjacent low refractive index layer 111 is increased, and the refractive index is further increased. Because.

The term “silicon-containing hydrated oxide” in the present specification may be any of a hydrate of an inorganic silicon compound, a hydrolyzate and / or a condensate of an organosilicon compound. More preferably has a silanol group.

The coating amount of the silicon-containing hydrated oxide is 3 to 30% by mass, preferably 3 to 10% by mass, more preferably 3 to 8% by mass. This is because when the coating amount is 30% by mass or less, the desired refractive index of the high refractive index layer can be obtained, and when the coating amount is 3% or more, particles can be stably formed.

As a method of coating the titanium oxide particles with a silicon-containing hydrated oxide, it can be produced by a conventionally known method. For example, JP-A-10-158015, JP-A-2000-204301, JP-A-2007 Reference can be made to the matters described in Japanese Patent No. 246351.

The content of the inorganic oxide particles 112a in the high refractive index layer 112 is preferably 15 to 90% by mass, and preferably 20 to 85% by mass with respect to 100% by mass of the solid content of the high refractive index layer 112. More preferably, the content is 30 to 85% by mass from the viewpoint of improving the reflectance.

(Other additives)
Each refractive index layer (111, 112) preferably contains a surfactant from the viewpoint of applicability when formed by coating. Anionic surfactants, nonionic surfactants, amphoteric surfactants, and the like can be used as the surfactant used for adjusting the surface tension during coating, but anionic surfactants are more preferable. Preferred compounds include those containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule.

Anionic surfactants include alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkane or olefin sulfonate, alkyl sulfate ester salt, polyoxyethylene alkyl or alkyl aryl ether sulfate salt, alkyl phosphate, alkyl diphenyl ether A surfactant selected from the group consisting of disulfonates, ether carboxylates, alkylsulfosuccinates, α-sulfo fatty acid esters and fatty acid salts, condensates of higher fatty acids with amino acids, naphthenates, etc. may be used. it can. Preferred anionic surfactants are alkylbenzene sulfonates (especially those of linear alkyls), alkanes or olefin sulfonates (especially secondary alkane sulfonates, α-olefin sulfonates), alkyl sulfates Salts, polyoxyethylene alkyl or alkylaryl ether sulfates (especially polyoxyethylene alkyl ether sulfates), alkyl phosphates (especially monoalkyl type), ether carboxylates, alkyl sulfosuccinates, α-sulfo fatty acid esters and A surfactant selected from the group consisting of fatty acid salts, and alkylsulfosuccinate is particularly preferable.

The content of the surfactant in each refractive index layer is preferably 0.001 to 0.5 mass%, and preferably 0.005 to 0.3 mass% with respect to the total solid content in each refractive index layer. % Is more preferable.

Each refractive index layer preferably contains a polymer dispersant from the viewpoint of dispersion stability of the coating solution. The polymer dispersant refers to a polymer dispersant having a weight average molecular weight of 10,000 or more. Preferably, the polymer has a hydroxyl group substituted at the side chain or terminal. For example, a polymer obtained by copolymerizing 2-ethylhexyl acrylate with an acrylic polymer such as sodium polyacrylate or polyacrylamide, polyethylene glycol or the like. Examples include polyethers such as polypropylene glycol, polyvinyl alcohol, and the like. A commercially available polymer dispersant may be used, and examples of such a polymer dispersant include Marialim AKM-0531 (manufactured by NOF Corporation). The content of the polymer dispersant is preferably 0.1 to 10% by mass in terms of solid content with respect to the refractive index layer.

Each refractive index layer may further contain an emulsion resin. By including the emulsion resin, the flexibility of the film is increased and the workability such as sticking to glass is improved.

An emulsion resin is a resin in which fine resin particles having an average particle diameter of about 0.01 to 2.0 μm, for example, are dispersed in an emulsion state in an aqueous medium. Obtained by emulsion polymerization using a molecular dispersant.

Examples of the polymer dispersant containing a hydroxyl group include those obtained by copolymerizing 2-ethylhexyl acrylate with an acrylic polymer such as sodium polyacrylate and polyacrylamide, polyethers such as polyethylene glycol and polypropylene glycol, polyvinyl Examples thereof include alcohol, and polyvinyl alcohol is particularly preferable.

Polyvinyl alcohol used as a polymer dispersant is an anion-modified polyvinyl alcohol having an anionic group such as a cation-modified polyvinyl alcohol or a carboxyl group in addition to ordinary polyvinyl alcohol obtained by hydrolysis of polyvinyl acetate. Further, modified polyvinyl alcohol such as silyl-modified polyvinyl alcohol having a silyl group is also included. Polyvinyl alcohol has a higher effect of suppressing the occurrence of cracks when forming each refractive index layer when the average degree of polymerization is higher, but when the average degree of polymerization is within 5000, the viscosity of the emulsion resin is not high, and the production Sometimes easy to handle. Accordingly, the average degree of polymerization is preferably 300 to 5000, more preferably 1500 to 5000, and particularly preferably 3000 to 4500. The saponification degree of polyvinyl alcohol is preferably 70 to 100 mol%, more preferably 80 to 99.5 mol%.

Examples of the resin that is emulsion-polymerized with the above polymer dispersant include homopolymers or copolymers of ethylene monomers such as acrylic acid esters, methacrylic acid esters, vinyl compounds, and styrene compounds, and diene compounds such as butadiene and isoprene. Examples thereof include acrylic resins, styrene-butadiene resins, ethylene-vinyl acetate resins, and these resins can also be used as resins constituting each refractive index layer.

In addition to the above, each refractive index layer includes, for example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, and JP-A-57-74192. JP-A-57-87989, JP-A-60-72785, JP-A-61465991, JP-A-1-95091 and JP-A-3-13376, etc. No. 42993, 59-52689, 62-280069, 61-242871, and JP-A 4-219266, etc., optical brighteners, sulfuric acid, phosphoric acid, acetic acid , PH adjusters such as citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, antifoaming agents, lubricants such as diethylene glycol, preservatives, antistatic agents, Tsu DOO agent may contain various known additives such as a light stabilizer such as hindered amine.

(Membrane design)
The solar

reflective film

10, 10 ′ of this embodiment has an ultraviolet reflective laminated portion 11 having at least one unit in which a low refractive index layer 111 and a high refractive index layer 112 are laminated. The range of the total number of layers of the low refractive index layer 111 and the high refractive index layer 112 is 100 layers or less, more preferably 45 layers or less. Although a minimum is not specifically limited, It is preferable that it is 5 layers or more. Considering light scattering and reflection intensity, the total number of layers of the low refractive index layer 111 and the high refractive index layer 112 per one ultraviolet reflection laminated portion 11 is preferably 7 to 23 layers.

In addition, it is preferable to design a large difference in refractive index between the low refractive index layer 111 and the high refractive index layer 112 from the viewpoint that the reflectance with respect to ultraviolet rays that are desired light beams can be increased with a small number of layers. In this embodiment, the difference in refractive index between at least two adjacent layers (low refractive index layer 111 and high refractive index layer 112) is preferably 0.1 or more, more preferably 0.25 or more, and further preferably Is 0.3 or more, more preferably 0.35 or more. The upper limit is not particularly limited, but is usually 1.4 or less. However, for example, when the outermost layer is formed as a layer for protecting the film or when the lowermost layer is formed as an adhesion improving layer with the substrate, the above-mentioned preferred refraction is performed with respect to the outermost layer and the lowermost layer. A configuration outside the range of the rate difference may be used. In addition, about the refractive index difference between each refractive index layer in the ultraviolet reflective lamination part 11, and a required number of layers, it can calculate using commercially available optical design software.

The low refractive index layer 111 preferably has a refractive index of 1.10 to 1.60, more preferably 1.30 to 1.55. The high refractive index layer 112 preferably has a refractive index of 1.80 to 2.50, more preferably 1.80 to 2.20.

Since reflection at the interface between adjacent layers depends on the refractive index ratio between layers, the larger this refractive index ratio, the higher the reflectance. In addition, when the optical path difference between the reflected light on the surface of the layer and the reflected light on the bottom of the layer is a relationship expressed by n · d = wavelength / 4 when viewed as a single layer film, the reflected light is controlled to be strengthened by the phase difference. The reflectance can be increased. Here, n is the refractive index, d is the physical film thickness of the layer, and n · d is the optical film thickness. By utilizing this optical path difference, reflection can be controlled. Using this relationship, the refractive index and film thickness of each layer are controlled to control the transmission of visible light and the reflection of ultraviolet light.

Further, it is preferable that the relationship between the average thickness dH of the high refractive index layer 112 and the average thickness dL of the low refractive index layer 111 satisfies the following formulas (1) and (2).

The thickness per layer of the high refractive index layer 112 (thickness after drying) is preferably 20 to 80 nm, more preferably 30 to 70 nm, and more preferably 40 to 60 nm. The thickness per layer of the low refractive index layer 11121 (thickness after drying) is preferably 40 to 100 nm, more preferably 50 to 90 nm, and more preferably 60 to 80 nm.

(Production method of UV reflection laminated part)
Although there is no restriction | limiting in particular in the manufacturing method of the ultraviolet reflective lamination | stacking part 11 in the sunlight reflective films 10 and 10 'of this form, Large area and mass production are possible, Manufacture is easy, and it is water-soluble suitably. A film forming method by coating is preferable because it contains a functional resin. The coating method may be sequential coating or simultaneous multi-layer coating, but simultaneous multi-layer coating is preferable because productivity is improved.

Examples of the coating method include a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a curtain coating method, or US Pat. Nos. 2,761,419 and 2,761,791. A slide bead coating method using an hopper, an extrusion coating method, or the like is preferably used.

The solvent for preparing the coating solution for the low refractive index layer, the coating solution for the high refractive index layer, and the coating solution for the resin layer is not particularly limited, but water, an organic solvent, or a mixed solvent thereof is preferable. In this embodiment, since a water-soluble resin can be used as a suitable resin, an aqueous solvent can be used. Compared to the case where an organic solvent is used, the aqueous solvent does not require a large-scale production facility, so that it is preferable in terms of productivity and also in terms of environmental conservation.

Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, and 1-butanol, esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethyl ether, Examples thereof include ethers such as propylene glycol monomethyl ether and ethylene glycol monoethyl ether, amides such as dimethylformamide and N-methylpyrrolidone, and ketones such as acetone, methyl ethyl ketone, acetylacetone and cyclohexanone. These organic solvents may be used alone or in combination of two or more. From the viewpoint of environment, simplicity of operation, etc., the solvent of the coating solution is preferably water or a mixed solvent of water and methanol, ethanol, or ethyl acetate, and more preferably water.

The concentration of the resin (water-soluble resin or the like) in the coating solution for the low refractive index layer is preferably 0.5 to 10% by mass. The concentration of the inorganic oxide particles in the coating solution for the low refractive index layer is preferably 1 to 50% by mass. The concentration of the resin (water-soluble resin or the like) in the coating solution for the high refractive index layer is preferably 0.5 to 10% by mass. The concentration of the inorganic oxide particles in the coating solution for the high refractive index layer is preferably 1 to 50% by mass.

The method for preparing the coating solution for the low refractive index layer and the coating solution for the high refractive index layer is not particularly limited. For example, inorganic oxide particles, resins (such as water-soluble resins), and other additives added as necessary The method of adding an additive and stirring and mixing is mentioned. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed at one time while stirring. If necessary, it is further adjusted to an appropriate viscosity using a solvent.

The temperature of the coating solution for the low refractive index layer and the coating solution for the high refractive index layer during simultaneous multilayer coating is preferably 25 to 60 ° C. when using the slide bead coating method or the curtain coating method, and 30 A temperature range of ˜45 ° C. is more preferred.

The viscosity of the coating solution for the low refractive index layer and the coating solution for the high refractive index layer when performing simultaneous multilayer coating is not particularly limited. However, when the slide bead coating method is used, it is preferably in the range of 5 to 100 mPa · s, more preferably in the range of 10 to 50 mPa · s in the preferred temperature range (25 to 60 ° C.) of the above coating solution. is there. When the curtain coating method is used, in the preferable temperature range (25 to 60 ° C.) of the above coating solution, a range of 5 to 1200 mPa · s is preferable, and a range of 25 to 500 mPa · s is more preferable. . If it is the range of such a viscosity, simultaneous multilayer coating can be performed efficiently.

The viscosity of the coating solution at 15 ° C. is preferably 100 mPa · s or more, more preferably 100 to 30,000 mPa · s, still more preferably 3,000 to 30,000 mPa · s, and most preferably 10 , 30,000 to 30,000 mPa · s.

The conditions for the coating and drying method are not particularly limited. For example, in the case of the sequential coating method, first, the silver reflective layer 13 and the corrosion prevention layer 14 are formed on one surface of the resin film support 12 as shown in FIG. Is formed on the other surface (light incident surface side) of the resin film-like support 12 on which is formed, or on one side of the resin film-like support 12 as shown in FIG. On the corrosion prevention layer 14 on which the layer 14 is formed, either the low refractive index layer coating liquid or the high refractive index layer coating liquid is applied to the resin film-like support 12 or the corrosion prevention layer 14. Then, the other coating liquid of the coating solution for the low refractive index layer and the coating liquid for the high refractive index layer is coated and dried on the coating film made of the one coating liquid, and the laminated film precursor (unit ). Next, the number of units necessary for expressing the desired ultraviolet reflection performance is sequentially applied and dried by the above method to obtain a laminated film precursor. When drying, it is preferable to dry the formed coating film at 30 ° C. or higher. For example, drying is preferably performed in the range of a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 5 to 100 ° C. (preferably 10 to 50 ° C.). For example, hot air of 40 to 60 ° C. is blown for 1 to 5 seconds. dry. As a drying method, warm air drying, infrared drying, and microwave drying are used. Further, drying in a multi-stage process is preferable to drying in a single process, and it is more preferable to set the temperature of the constant rate drying section <the temperature of the rate-decreasing drying section. In this case, the temperature range of the constant rate drying section is preferably 30 to 60 ° C., and the temperature range of the decreasing rate drying section is preferably 50 to 100 ° C.

The conditions for the coating and drying method when simultaneous multilayer coating is performed are as follows. The coating solution for low refractive index layer and the coating solution for high refractive index layer are heated to 30 to 60 ° C. Alternatively, after the simultaneous application of the low refractive index layer coating liquid and the high refractive index layer coating liquid on the corrosion prevention layer 14, the temperature of the formed coating film is preferably cooled to 1 to 15 ° C. (set) ) And then drying at 10 ° C. or higher is preferred. More preferable drying conditions are a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10 to 50 ° C. For example, it is dried by blowing warm air of 80 ° C. The drying time is not particularly limited, but for example, about 1 to 5 seconds is preferable from the viewpoint of productivity. Moreover, as a cooling method immediately after application | coating, it is preferable to carry out by a horizontal set system from a viewpoint of the uniformity improvement of the formed coating film.

[Silver reflective layer 13]
The silver reflective layer 13 in the solar

reflective film

10, 10 ′ of this embodiment is a layer mainly composed of silver or silver having a function of reflecting light in the visible to infrared region; a wavelength of 280 to 2500 nm. As shown in FIGS. 1 and 2, the silver reflecting layer 13 only needs to be provided on the lower layer side than the ultraviolet reflecting laminated portion 11 on the light incident surface side. Here, the main component of silver is that the silver content in the silver-containing alloy constituting the silver reflecting layer 13 is the largest, preferably the silver content is 70% by mass or more, more preferably 80%. It is 90 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%. The other alloy components contained in the silver-containing alloy are elements composed of Al, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au from the viewpoint of film formation temperature, solar reflectance, and corrosion resistance. A material containing any element selected from the group is preferable, and Al is preferable.

The surface reflectance of the silver reflective layer 13 (specifically, the reflectance in the visible light to infrared region; the reflectance at a wavelength of 280 to 2500 nm) is preferably 80% or more, and more preferably 90% or more. The surface reflectance of the silver reflective layer 13 can be measured using a commercially available spectrophotometer.

Further, a layer made of a metal oxide such as SiO ₂ or TiO ₂ (not shown in FIGS. 1 and 2) may be provided on the silver reflecting layer 13 to further improve the reflectance.

As the method for forming the silver reflecting layer 13 in the present invention, for example, both a wet method and a dry method can be used.

The wet method is a general term for a plating method or a metal complex solution coating method, and is a method of forming a film by depositing a metal from a solution. Specific examples include silver mirror reaction and silver layer formation by firing of a silver complex ink (specifically, firing of a coating film formed by applying a silver coating liquid composition containing a silver complex compound).

On the other hand, the dry method is a general term for a vacuum film forming method, and specifically includes 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. Etc. 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. That is, in the manufacturing method of the sunlight reflective film 10 of this invention, it is preferable to form the silver reflection layer 13 by vapor deposition of silver.

The thickness of the silver reflecting layer 13 is preferably 10 to 200 nm, more preferably 30 to 150 nm, from the viewpoint of sunlight reflectance, corrosion resistance, and the like.

(Silver complex compound having a ligand that can be vaporized and eliminated)
When the silver reflective layer 13 is formed, the silver reflective layer 13 may be formed by heating and firing a coating film containing a silver complex compound from which a ligand can be vaporized and desorbed.

“Silver complex compound having a ligand that can be vaporized / desorbed” has a ligand for stably dissolving silver in a solution, but the ligand is removed by removing the solvent and heating and firing. Is a silver complex compound that can be thermally decomposed into CO ₂ or a low molecular weight amine compound, vaporized / desorbed, and only metallic silver remains.

As for such a silver complex compound and a method for producing the same, for example, a silver complex compound and a method for producing the same described in paragraphs “0064” to “0089” of JP-A-2012-137579, which are publicly known, can be used as appropriate. .

[Corrosion prevention layer 14]
The corrosion prevention layer 14 prevents intrusion of moisture and chemicals in the air into the silver reflection layer 13 (mirror surface) (and thus prevents the silver reflection layer 13 from corroding silver and silver-containing alloy materials (particularly silver)). Furthermore, it is provided for the purpose of protection from external mechanical pressure such as impact and scratching. That is, the corrosion prevention layer 14 can prevent the silver reflection of the silver reflection layer 13 and maintain the reflection of sunlight. As a result, the durability of the

sunlight reflecting films

10, 10 ′ can be improved. For the above purpose, the corrosion prevention layer 14 is desirably provided adjacent to the silver reflective layer 3. However, as long as it is within the range that can achieve the above object, it may be provided apart from (without adjoining) the silver reflecting layer 13, and in such a case, it may contain a silver corrosion inhibitor. preferable.

The corrosion prevention layer 14 may be composed of only one layer or may be composed of a plurality of layers.

(Corrosion prevention layer 14a)
When the corrosion prevention layer 14 composed of a plurality of layers is provided, as the corrosion prevention layer 14a provided on the surface in contact with the silver reflective layer 13, the corrosion prevention layer 14b provided on the corrosion prevention layer 14a after achieving the above-mentioned purpose. And the silver reflection layer 13. Therefore, the corrosion prevention layer 14a needs to have an adhesive property for bringing the corrosion prevention layer 14b and the silver reflection layer 13 into close contact with each other and a smoothness for drawing out the high reflection performance that the silver reflection layer 13 originally has. Moreover, in the aspect shown in FIG. 2, since it is located in the light-incidence surface side rather than the silver reflection layer 13, what is excellent in transparency (especially sunlight transmittance | permeability) is desirable.

The binder (resin) used for the corrosion prevention layer 14a is not particularly limited as long as it satisfies the above conditions of adhesion, smoothness, and (and further transparency). It can be selected appropriately. Of these, acrylic, silicone, olefin, and polyester are preferable. Further, the corrosion prevention layer 14a contains an appropriate amount of a later-described corrosion inhibitor.

The thickness of the corrosion prevention layer 14a is preferably 0.05 to 5 μm, more preferably 0.1 to 3 μm. By satisfying this range, it is possible to cover the unevenness of the surface of the silver reflecting layer 13 (silver vapor deposition surface) while maintaining adhesion, to improve smoothness, and to sufficiently cure the corrosion prevention layer 14a. As a result, the reflectance of the solar reflective film 10 of the present embodiment can be increased.

(Corrosion prevention layer 14b)
In the case of providing the corrosion prevention layer 14 composed of a plurality of layers, the corrosion prevention layer 14b provided via the silver reflection layer 13 and the corrosion prevention layer 14a achieves the above-mentioned purpose, and in particular, adherence to the ultraviolet reflection laminated portion. It is a layer provided for maintaining the above. Accordingly, the corrosion prevention layer 14b needs to have good adhesion to improve the adhesion to the ultraviolet reflective laminate, and smoothness and hydrophilicity to enable uniform application of the ultraviolet reflective laminate by coating.

The binder (resin) used for the corrosion prevention layer 14b is not particularly limited as long as the original purpose of the corrosion prevention layer can be achieved, and can be appropriately selected from binders (resins) described later. . Among them, an acrylic resin having a hydroxyl group or a carboxyl group is preferable. Further, the corrosion prevention layer 14b also contains an appropriate amount of a later-described corrosion inhibitor.

The thickness of the corrosion prevention layer 14b is preferably 0.05 to 5 μm, more preferably 0.1 to 3 μm. By satisfying this range, the corrosion prevention layer 14b can be sufficiently cured while maintaining adhesion, and as a result, intrusion of moisture and chemical substances in the air into the silver reflective layer 13 (mirror surface) is prevented ( As a result, the silver reflecting layer 13 can be protected from silver and silver-containing alloy materials (especially silver) and further protected from external mechanical pressure, such as impact and scratches. It becomes possible to improve the weather resistance (durability), scratch resistance, and reflectance of the reflective film 10.

The thickness of the corrosion prevention layer 14 (when there are two or more layers) is preferably 1 to 10 μm, more preferably 2 to 8 μm. If the thickness of the corrosion prevention layer 14 is 1 μm or more, moisture in the air or chemical substances enter the silver reflecting layer 13 (mirror surface), and mechanical pressure from the outside, for example, impact or scratching, etc. Can be protected from. If the thickness of the corrosion prevention layer 14 is 10 μm or less, the flexibility can be sufficiently maintained, so that cracks and cracks can be effectively prevented.

The corrosion prevention layer 14 can maintain high film adhesion with the silver reflective layer 13 even if it is installed over a long period of time in an outdoor environment, and the above object can be achieved. Further, as shown in FIG. 2, the water in the corrosion prevention layer 14 that covers the silver reflection layer 13 is formed so that a water-soluble polymer (= a constituent member of the ultraviolet reflection laminated portion 11) can be formed on the corrosion prevention layer 14. The contact angle is preferably less than 90 °, more preferably 85 to 40 °, even more preferably 80 to 40 °, and particularly preferably 75 to 40 °. The water contact angle of the corrosion prevention layer 14 can be measured using an existing measuring apparatus, and can be measured using, for example, DM300 manufactured by Kyowa Interface Chemical Co., Ltd.

The corrosion prevention layer 14 is mainly composed of a binder (resin) so that it can maintain high film adhesion with the silver reflective layer 13 even when installed for a long time in an outdoor environment, and can achieve the above-mentioned purpose. Further, it contains a corrosion inhibitor of the same metal as the silver or silver-containing alloy material of the silver reflecting layer 13 (particularly silver). Among these, as the binder (resin) of the corrosion prevention layer 14, for example, the following resins can be preferably used. Cellulose ester, polyester, polycarbonate, polyarylate, polysulfone (including polyethersulfone), polyethylene terephthalate, polyethylene naphthalate, polyester, polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose Acetate butyrate, polyvinylidene chloride, polyvinyl alcohol, ethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene, polymethylpentene, polyether ketone, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, An acrylic resin etc. can be mentioned. Of these, acrylic resin and polyester are preferable.

(Corrosion inhibitor)
As a corrosion inhibitor for the corrosion prevention layer 14, from the viewpoint of preventing corrosion of silver and the silver-containing alloy material of the silver reflection layer 13, the same kind of metal as the silver and silver-containing alloy material of the silver reflection layer 13 (particularly silver, If necessary, it has a corrosion inhibitor for any element selected from the group consisting of Al, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au), particularly an adsorbing group for silver. preferable. Here, “corrosion” refers to a phenomenon in which a metal (particularly 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 0.001 to 0.1 g / m ² .

The same kind of metal as the silver or silver-containing alloy material of the silver reflecting layer 13 (in particular, silver, and if necessary, selected from the element group consisting of Al, Cr, Cu, Ni, Ti, Mg, Rh, Pt and Au) The corrosion inhibitor of any element) is preferably selected from a silicone-modified resin, a silane coupling agent, a compound containing a plurality of thiol groups, and a corrosion inhibitor having an adsorbing group for silver described below.

Corrosion inhibitors having an adsorptive group for silver include amines and derivatives thereof, compounds having a pyrrole ring, compounds having a triazole ring such as benzotriazole, compounds having a pyrazole ring, compounds having a thiazole ring, and having an imidazole ring It is desirable to be selected from a compound, a compound having an indazole ring, a copper chelate compound, a thiourea, a compound having a mercapto group, a naphthalene-based compound, or a mixture thereof. In compounds such as benzotriazole, the ultraviolet absorber may also serve as a corrosion inhibitor. It is also possible to use a silicone-modified resin. The silicone-modified resin is not particularly limited.

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

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

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

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

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

Examples of the compound having an imidazole ring include imidazole, histidine, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methyl Imidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecyl Imidazole, 2-phenyl-4-methyl-5-hydromethylimidazole, 2-phenyl-4,5 dihydroxymethylimidazole, 4-formylimidazole, 2-methyl-4-formylimidazole, 2-phenyl-4- Formylimidazole, 4-methyl-5-formylimidazole, 2-ethyl-4-methyl-5-formylimidazole, 2-phenyl-4-methyl-4-formylimidazole, 2-mercaptobenzimidazole, etc. These mixtures are mentioned.

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

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

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

As a compound having a mercapto group, mercaptoacetic acid, thiophenol, 1,2-ethanediol, 3-mercapto-1,2,4-triazole, 1-methyl-3-mercapto can be used by adding the above-described materials. -1,2,4-triazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, glycol dimercaptoacetate, 3-mercaptopropyltrimethoxysilane, trimethylolpropane tris (β-thiopropionate) or the like Of the mixture.

Examples of naphthalene-based compounds include thionalide.

(Nitrogen-containing cyclic compound that can be used in the adjacent layer of the silver reflective layer 13)
When forming the silver reflective layer 13, when the silver reflective layer 13 is formed by heating and baking a coating film containing a silver complex compound from which the above-described ligand can be vaporized and desorbed, the silver reflective layer 13 is adjacent. It is preferable to contain a nitrogen-containing cyclic compound in a layer (for example, the above-described corrosion prevention layer 14, an anchor layer (not shown) that can be applied between the silver reflection layer 13 and the corrosion prevention layer 14). The content of the nitrogen-containing cyclic compound in the adjacent layer of the silver reflecting layer 13 is preferably 0.001 to 5% by mass, more preferably 0.01 to 1% by mass. When the content of the nitrogen-containing cyclic compound in the adjacent layer of the silver reflecting layer 13 is 0.001% by mass or more, the rust prevention and corrosion prevention functions of silver can be effectively expressed. When the content of the nitrogen-containing cyclic compound in the adjacent layer of the silver reflective layer 13 is 5% by mass or less, the embrittlement preventing function of the adjacent layer can be effectively expressed without coloring. As the nitrogen-containing cyclic compound, broadly, a corrosion inhibitor and an antioxidant having an adsorptive group for silver are preferably used.

In the corrosion inhibitor having an adsorptive group for silver, a desired silver corrosion prevention effect can be obtained by using a nitrogen-containing cyclic compound. The content of the corrosion inhibitor having an adsorptive group for silver in the adjacent layer of the silver reflective layer 13 is preferably 0.001 to 5% by mass, more preferably 0.01 to 1% by mass. . If the content of the corrosion inhibitor having an adsorptive group for silver in the adjacent layer of the silver reflection layer 13 is 0.001% by mass or more, the silver corrosion prevention function can be effectively expressed. If the content of the corrosion inhibitor having an adsorptive group for silver in the adjacent layer of the silver reflecting layer 13 is 5% by mass or less, the embrittlement preventing function of the adjacent layer can be effectively expressed without coloring. it can. For example, it is desirable to be selected from at least one of a compound having a pyrrole ring, a compound having a triazole ring, a compound having a pyrazole ring, a compound having an imidazole ring, a compound having an indazole ring, or a mixture thereof.

As the compound having a pyrrole ring, compounds specifically exemplified in “Compounds having a pyrrole ring” among the compounds listed in the section of (Corrosion inhibitor) of [Corrosion prevention layer 14] described above can be used.

As the compound having a triazole ring, compounds specifically exemplified as “compound having a triazole ring” among the compounds listed in the section of (Corrosion inhibitor) of [Corrosion prevention layer 14] can be used.

As the compound having a pyrazole ring, compounds specifically exemplified as “compound having a pyrazole ring” among the compounds listed in the section of (Corrosion inhibitor) of the above [Corrosion prevention layer 14] can be used.

As the compound having an imidazole ring, compounds specifically exemplified as “compound having an imidazole ring” among the compounds listed in the section of (Corrosion inhibitor) of [Corrosion prevention layer 14] described above can be used.

As the compound having an indazole ring, compounds specifically exemplified as “compound having an indazole ring” among the compounds listed in the section of (Corrosion inhibitor) of the above [Corrosion prevention layer 14] can be used.

(Antioxidant)
Adjacent layers of the silver reflective layer 13 in the solar reflective film 10 of this embodiment (for example, the above-described corrosion prevention layer 14, an anchor layer (not shown) that can be applied between the silver reflection layer 13 and the corrosion prevention layer 14), and the like. As the nitrogen-containing cyclic compound contained in), an antioxidant can also be used. When the content of the antioxidant in the adjacent layer of the silver reflective layer 13 is 0.001% by mass or more, the silver antioxidant function can be effectively expressed. When the content of the antioxidant in the adjacent layer of the silver reflective layer 13 is 5% by mass or less, the embrittlement preventing function of the adjacent layer can be effectively expressed without coloring.

As the antioxidant, it is preferable to use a phenol-based antioxidant, a thiol-based antioxidant, and a phosphite-based antioxidant.

Examples of phenolic antioxidants include 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 2,2′-methylenebis (4-ethyl-6-t- Butylphenol), tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 2,6-di-t-butyl-p-cresol, 4,4 '-Thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 1,3,5-tris (3', 5'-di-t -Butyl-4'-hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ,bird Tylene glycol bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-di-methyl-2- [β- (3-t-butyl -4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene and the like. In particular, the phenolic antioxidant preferably has a molecular weight of 550 or more.

Examples of the thiol antioxidant include distearyl-3,3'-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), and the like.

Examples of the phosphite antioxidant include tris (2,4-di-t-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, di (2,6-di-t-butylphenyl) pentaerythritol. Diphosphite, bis- (2,6-di-t-butyl-4-methylphenyl) -pentaerythritol diphosphite, tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylene-diphosphonite 2,2′-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and the like.

In addition, the above antioxidant and the following light stabilizer can be used in combination. When the content of the light stabilizer in the adjacent layer of the silver reflective layer 13 is 0.001% by mass or more, the light stabilizing function can be effectively expressed. When the content of the light stabilizer in the adjacent layer of the silver reflective layer 13 is 5% by mass or less, the embrittlement preventing function of the adjacent layer can be effectively expressed without coloring.

Examples of hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, 1-methyl- 8- (1,2,2,6,6-pentamethyl-4-piperidyl) -sebacate, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl ] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6, 6-Tetrame Lupiperidine, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butane-tetracarboxylate, triethylenediamine, 8-acetyl-3-dodecyl-7,7,9 , 9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione.

Other nickel-based UV stabilizers include [2,2′-thiobis (4-t-octylphenolate)]-2-ethylhexylamine nickel (II), nickel complex-3,5-di-t-butyl-4- Hydroxybenzyl phosphate monoethylate, nickel dibutyl dithiocarbamate, etc. can also be used.

In particular, as the hindered amine light stabilizer, a hindered amine light stabilizer containing only a tertiary amine is preferable. Specifically, bis (1,2,2,6,6-pentamethyl-4-piperidyl) is preferable. Sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl malonate, or A condensate of 1,2,2,6,6-pentamethyl-4-piperidinol / tridecyl alcohol and 1,2,3,4-butanetetracarboxylic acid is preferred.

[Resin film-like support 12]
As the resin film-like support 12, various conventionally known resin films can be used. For example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyethylene naphthalate polyester film, 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 , Polymethylpentenef Can Lum, polyether ketone film, 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. In particular, it is preferable to use a polyester film such as polyethylene terephthalate or an acrylic film, and it may be a film manufactured by melt casting film formation or a film manufactured by solution casting film formation.

As shown in FIG. 2, when the resin film-like support 12 is provided at a position farther from the light incident side than the silver reflection layer 13, ultraviolet rays hardly reach the resin film-like support 12. In particular, ultraviolet rays are less likely to reach the resin film-like support 12 by reflecting the ultraviolet rays by the ultraviolet reflecting portion 11 on the light incident side of the resin film-like support 12. Therefore, the resin film-like support 12 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 film-like support 12.

In the

sunlight reflecting films

10 and 10 ′ of this embodiment, since the ultraviolet reflecting portion 11 having an excellent ultraviolet reflecting function is provided on the light incident side, as shown in FIG. Since the ultraviolet rays hardly reach the resin film-like support 12 even if the ultraviolet reflecting part 11 is provided on the surface side), various conventionally known resin films can be used. In particular, when the silver reflective layer 13 is provided on the side opposite to the light incident surface side of the resin film-like support 12, the resin film-like support 12 transmits sunlight (particularly, light in the visible to infrared region). It is desirable to use a resin film that can be used. From such a viewpoint, the transmittance of sunlight (particularly visible light to infrared light; wavelength of 400 to 2500 nm) of the resin film-like support 12 is preferably 70% or more, more preferably 80% or more, and still more preferably. It is 90% or more, particularly preferably 95% or more. The transmittance of sunlight (wavelength of 400 to 2500 nm) can be measured with a spectrophotometer having an integrating sphere.

The thickness of the resin film-like support 12 is preferably set to an appropriate thickness according to the type and purpose of the resin. For example, it is generally in the range of 10 to 250 μm. The thickness is preferably 20 to 200 μm.

[Anchor layer (not shown)]
In the solar

reflective film

10, 10 ′ of this embodiment, an anchor layer (not shown in FIGS. 1 and 2) may be provided. Such an anchor layer is made of a resin and is a layer provided for closely attaching the resin film-like support 12 and the silver reflecting layer 13. Therefore, the anchor layer has an adhesion property that allows the resin film-like support 12 and the silver reflective layer 13 to adhere to each other, heat resistance that can withstand heat when the silver reflective layer 13 is formed by a vacuum deposition method, and the silver reflective layer 13. Need to have smoothness and transparency (sunlight transmittance) in order to bring out the high reflection performance inherently.

The resin used for the anchor layer is not particularly limited as long as it satisfies the above conditions of adhesion, heat resistance, transparency, and smoothness. Polyester resin, acrylic resin, melamine resin, epoxy resin , Polyamide resins, vinyl chloride resins, vinyl chloride vinyl acetate copolymer resins, etc., or a mixture of these resins can be used. From the viewpoint of weather resistance, a polyester resin and a melamine resin mixed resin or a polyester resin A mixed resin of acrylic resin is preferable, and a thermosetting resin in which a curing agent such as isocyanate is further mixed is more preferable.

The thickness of the anchor layer is preferably 0.01 to 3 μm, more preferably 0.1 to 2 μm. By satisfying this range, the unevenness of the surface of the resin film-like support 11 can be concealed while maintaining the adhesiveness, smoothness can be improved, and the anchor layer can be sufficiently cured. It becomes possible to increase the reflectance of the solar reflective film 10.

The anchor layer preferably contains the corrosion inhibitor described in the above (Corrosion prevention layer 14) (Corrosion prevention layer).

As shown in FIG. 1, when the silver reflective layer 13 is provided on the side opposite to the light incident surface side of the resin film support 12, the anchor provided between the resin film support 12 and the silver reflective layer 13. It is desirable that the layer can also transmit sunlight (particularly visible light to infrared light). From such a viewpoint, the transmittance of sunlight (particularly, visible light to infrared light; wavelength of 400 to 2500 nm) of the anchor layer is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, Especially preferably, it is 95% or more of range.

In addition, the formation method of an anchor layer can use conventionally well-known coating methods, such as a gravure coat method, a reverse coat method, and a die coat method.

[Adhesive layer 15]
It is preferable that the solar

reflective film

10, 10 ′ of this embodiment has an adhesive layer 15 for bonding to a support base material (a self-supporting base material that is a constituent member of the solar reflector) described later. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 15 is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, silicon pressure-sensitive adhesives, urethane pressure-sensitive adhesives, polyvinyl butyral pressure-sensitive adhesives, and ethylene-vinyl acetate pressure-sensitive adhesives. be able to. The adhesive layer 15 may be formed on the surface opposite to the sunlight incident surface side (outermost surface; except for the release material 16) in the

sunlight reflecting films

10, 10 ′.

The acrylic pressure-sensitive adhesive may be either solvent-based or emulsion-based, but is preferably a solvent-based pressure-sensitive adhesive because it is easy to increase the adhesive strength and the like, and among them, those obtained by solution polymerization are preferable. Examples of the raw material for producing such a solvent-based acrylic pressure-sensitive adhesive by solution polymerization include, for example, acrylic acid esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and acryl acrylate as main monomers serving as a skeleton, As a comonomer to improve cohesive strength, vinyl acetate, acrylonitrile, styrene, methyl methacrylate, etc., to further promote crosslinking, to give stable adhesive strength, and to maintain a certain level of adhesive strength even in the presence of water Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, and glycidyl methacrylate. Since the adhesive layer of the laminated film requires a particularly high tack as the main polymer, those having a low glass transition temperature (Tg) such as butyl acrylate are particularly useful.

For example, a stabilizer, a surfactant, an ultraviolet absorber, a flame retardant, an antistatic agent, an antioxidant, a heat stabilizer, a lubricant, a filler, a coloring agent, an adhesion modifier, and the like are added to the adhesive layer 15 as additives. It can also be contained.

The thickness of the adhesive layer 15 is preferably 1 μm to 100 μm, more preferably 3 to 50 μm. If it is 1 micrometer or more, there exists a tendency for adhesiveness to improve and sufficient adhesive force is acquired. When the thickness is larger than 100 μm, the flatness of the silver reflecting layer tends to be lost due to the local shrinkage and expansion of the adhesive layer, so that it is preferably 100 μm or less.

[Release material 16]
The solar

reflective film

10, 10 ′ of this embodiment may have a release material 16 on the side opposite to the light incident side of the adhesive layer 15. For example, when the solar reflective film 10 is shipped, the release material 16 is shipped in a state of sticking to the adhesive layer 15, and the solar reflective film 10 having the adhesive layer 15 is peeled from the release material 16 to form a solar reflector. A solar reflector and further a solar reflector can be formed by bonding to a self-supporting base material (support base material) which is a member.

The release material 167 may be any material that can impart protection to the silver reflective layer 13. 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 plastic film or sheet such as sheet, fluorine film, or resin film or sheet kneaded with titanium oxide, silica, aluminum powder, copper powder, etc. A resin film or sheet subjected to surface processing such as is used.

The thickness of the release material 16 is not particularly limited, but is usually preferably in the range of 12 to 250 μm.

Moreover, you may bond after providing a recessed part and a convex part before bonding these peeling materials 16 with the sunlight reflective film 10 (except for the peeling material 16), and have a recessed part and a convex part after bonding. It may be formed in such a manner that the bonding and forming so as to have a concave portion or a convex portion may be performed simultaneously.

[Scratch resistant layer 17]
The solar reflective film 10, 10 'of this embodiment is a scratch-resistant layer (hard coat layer; HC layer) on the side of the ultraviolet reflective laminated portion 11 where light is incident for the purpose of protecting the ultraviolet reflective laminated portion 11 from scratches. 17 is further preferable.

Examples of the curable resin used in the scratch-resistant layer 17 include a thermosetting resin and an active energy ray curable resin, but an active energy ray curable resin is preferable because of easy molding. Such curable resins can be used singly or in combination of two or more. As the curable resin, a commercially available product may be used, or a synthetic product may be used.

The active energy ray resin refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays and electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam. Is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin, an electron beam curable resin, and the like, and an ultraviolet curable resin that is cured by ultraviolet irradiation is preferable.

As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used. Of these, ultraviolet curable acrylate resins are preferred.

UV-curable acrylic / urethane resins generally contain 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. Only acrylate is indicated), and it can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by Dainippon Ink Co., Ltd.) and 1 part of Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) described in JP-A-59-151110 is preferably used. It is done.

The UV curable polyester acrylate resin can be easily obtained by reacting a monomer such as 2-hydroxyethyl acrylate, glycidyl acrylate, or acrylic acid with a hydroxyl group or carboxyl group at the end of the polyester (see, for example, JP-A No. 1987-101). 59-151112).

The ultraviolet curable epoxy acrylate resin is obtained by reacting a terminal hydroxyl group of an epoxy resin with a monomer such as acrylic acid, acrylic acid chloride, or glycidyl acrylate.

Examples of ultraviolet curable polyol acrylate resins include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta. Examples include erythritol pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate.

Furthermore, as photosensitizers (radical polymerization initiators) for these resins, benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl methyl ketal and the like Alkyl ethers: acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone (trade name Irgacure 184; BASF), 2-methyl-1 [4- (methylthio) phenyl] -2-mori Acetophenones such as folinopropan-1-one (trade name Irgacure 907; BASF); anthraquinones such as methylanthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone; thioxanthone, 2,4-diethylthioxanthone, 2, 4- Thioxanthones such as isopropyl thioxanthone; acetophenone dimethyl ketal, benzil ketals such as dimethyl ketal; can be used benzophenone, 4,4-bis benzophenones such as methylamino benzophenone and azo compounds. These may be used alone or in combination of two or more. In addition, tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiators such as benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate can be used in combination. it can. The amount of these radical polymerization initiators used is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the polymerizable component of the resin.

Examples of thermosetting resins include inorganic materials typified by polysiloxane.

Polysiloxane hard coat (HC layer 17) are those represented by the general formula _R m Si (OR _{') n} is the starting material. R and R ′ represent an alkyl group having 1 to 10 carbon atoms, and m and n are integers satisfying the relationship of m + n = 4. Specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-polopoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, terapentaethoxy Silane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxy Silane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, dimethyl Dimethoxysilane, dimethyl diethoxy silane, hexyl trimethoxy silane and the like. Γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- ( N-aminobenzylaminoethyl) -γ-aminopropylmethoxysilane / hydrochloride, γ-glycidoxypropyltrimethoxysilane, aminosilane, methylmethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloro Propyltrilimethoxysilane, hexamethyldisilazane, vinyltris (β-methoxyethoxy) silane, and octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride can also be used. A state in which a hydrolyzable group such as methoxy group or ethoxy group is substituted with a hydroxyl group is generally called a polyorganosiloxane hard coat. When this is applied onto a substrate and cured by heating, the dehydration condensation reaction is promoted, and the hard coat (HC layer 17) is formed by curing and crosslinking. Among these polyorganosiloxane hard coats, those having an organic group that is not eliminated by hydrolysis are methyl groups have the highest weather resistance. Moreover, if it is a methyl group, since the methyl group is uniformly and densely distributed on the surface after the hard coat film formation, the falling angle is also low. Therefore, in this application, it is preferable to use methylpolysiloxane.

If the polysiloxane hard coat (HC layer 17) is too thick, there is a risk that the scratch-resistant layer 17 will break due to stress, and if it is too thin, the hardness cannot be maintained. Therefore, the thickness is preferably 1 to 5 μm, and more preferably 1.5 to 3 μm.

Specific examples of the polyorganosiloxane hard coat (HC layer 17) include Surcoat series (manufactured by Doken), SR2441 (Toray Dow Corning), KF-86 (Shin-Etsu Silicon), Perma-New (registered trademark) 6000. (California Hardcoating Company) can be used.

The blending amount of the cured resin in the scratch-resistant layer 17 is preferably 20 to 70% by weight and more preferably 30 to 50% by weight with respect to 100% by weight (in terms of solid content) of the scratch-resistant layer. .

The thickness of the scratch-resistant layer 17 is preferably 0.1 to 20 μm, more preferably 1 to 15 μm, and more preferably 3 to 10 μm. If it is 0.1 μm or more, the hard coat property tends to be improved, and if it is 20 μm or more, the scratch-resistant layer has a large curl and the flex resistance tends to be lowered.

The scratch-resistant layer 17 can be produced by applying a cured resin layer forming composition (coating solution) by wire bar coating, spin coating, or dip coating, and can also be produced by a dry film forming method such as vapor deposition. it can. The composition (coating liquid) can be applied and formed into a film by a continuous coating apparatus such as a die coater, a gravure coater, or a comma coater. In the case of a polysiloxane hard coat, after application, after drying the solvent, a heat treatment is required for 30 minutes to several days at a temperature of 50 ° C. or more and 150 ° C. or less in order to promote curing and crosslinking of the hard coat. To do. In consideration of the heat resistance of the coated substrate and the stability of the substrate when it is made into a roll, it is preferable to perform the treatment at 40 ° C. or more and 80 ° C. or less for 2 days or more. In the case of an active energy ray curable resin, the reactivity varies depending on the irradiation wavelength, the illuminance, and the light amount of the active energy ray, and therefore it is necessary to select an optimum condition depending on the resin to be used.

The composition for forming the cured resin layer (coating liquid) may contain a solvent, or may be appropriately contained and diluted as necessary. Examples of the organic solvent contained in the coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), It can be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used.

When the adhesion to the lower layer of the scratch-resistant layer 17 is not obtained, a second anchor layer (primer layer; not shown in FIGS. 1 and 2) can be formed before the cured resin layer is laminated. The thickness of the second anchor layer is not particularly limited, but is about 0.1 to 10 μm. Preferable examples of the resin constituting the anchor layer include polyvinyl acetal resin and acrylic resin.

[Gas barrier layer]
A gas barrier layer (not shown in FIGS. 1 and 2) may be provided on the light incident side of the silver reflecting layer 13. It is preferable to provide a gas barrier layer between the scratch-resistant layer 17 and the silver reflective layer 13. Furthermore, it is preferable to provide a gas barrier layer between the adhesive layer 15 and the corrosion prevention layer 14. For details of the gas barrier layer, for example, paragraphs “0044” to “0096” of the publicly known international publication number WO2011 / 096151 A1 can be applied.

Further, the solar

reflective film

10, 10 ′ of the present embodiment includes an easy-adhesion layer (adhesive layer), an ultraviolet absorber-containing layer, a conductive layer, an antistatic layer, a gas barrier layer, depending on the environment and application used. 1 of functional layers such as antifouling layer, deodorant layer, droplet layer, slippery layer, abrasion resistant layer, antireflection layer, electromagnetic wave shielding layer, printing layer, fluorescent light emitting layer, hologram layer, release layer, adhesive layer, etc. You may have more than one.

<Sunlight reflector>
According to one aspect of the present invention, there is provided a solar reflector characterized by having the above-described solar

reflective film

10, 10 ′. The solar reflector has a structure in which the solar

reflective films

10 and 10 ′ are bonded to a self-supporting base material (support base material) through the adhesive layer 15. Here, in the case of “self-supporting substrate”, “self-supporting” means supporting the opposite edge portions when cut to a size used as a substrate for a solar reflector. By doing this, it indicates that the substrate has rigidity enough to carry the substrate. Since the base material of the solar reflector has self-supporting properties, it is easy to handle when it is installed in a solar reflective device described later, and the holding member for holding the solar reflector has a simple configuration. Therefore, it is possible to reduce the weight of the solar reflective device. For example, when the solar reflective device is used as a solar reflective device for solar thermal power generation, power consumption during solar tracking can be suppressed.

[Self-supporting substrate (supporting substrate)]
The self-supporting base material (supporting base material) may be a single layer or a shape in which a plurality of layers are laminated. Moreover, a single structure may be sufficient and it may be divided | segmented into plurality. As the shape of the supporting base material, it is preferable that the supporting substrate has a concave shape or can be a concave shape. Therefore, a support base material that is variable from a flat shape to a concave shape may be used, or a support base material that is fixed to a concave shape may be used. Since the support base material which can be changed into the concave shape can adjust the curvature of the solar reflective films 10 and 10 'which are joined by adjusting the curvature of the support base material. It is preferable because the reflection efficiency can be adjusted and a high regular reflectance can be obtained. Since the support base material to which the concave shape is fixed is not necessary to adjust the curvature, it is preferable from the viewpoint of adjustment cost.

Materials for self-supporting substrates (supporting substrates) include steel plates, copper plates, aluminum plates, aluminum-plated steel plates, aluminum alloy-plated steel plates, copper-plated steel plates, tin-plated steel plates, chrome-plated steel plates, stainless steel plates, etc. Examples thereof include wooden boards such as boards and plywood boards (preferably those that have been waterproofed), fiber reinforced plastic (FRP) boards, resin boards, and the like. Among these materials, it is preferable to use a metal plate from the viewpoint of high thermal conductivity. More preferably, it is a plated steel plate, stainless steel plate, aluminum plate or the like having not only high thermal conductivity but also good corrosion resistance. Most preferably, a steel plate combining a resin and a metal plate is used.

As the material for the resin film as the surface layer, various conventionally known resin films can be used. For example, the resin film mentioned to the resin film-like support body 12 mentioned above is mentioned. Among these, polycarbonate films, polyester films such as polyethylene terephthalate, norbornene resin films, cellulose ester films, and acrylic films are preferable. It is particularly preferable to use a polyester film such as polyethylene terephthalate or an acrylic film. The thickness of the resin film is preferably set to an appropriate thickness according to the type and purpose of the resin. For example, it is generally 10 to 250 μm, preferably 20 to 200 μm.

<Sunlight reflector>
According to another aspect of the present invention, there is provided a sunlight reflecting device having a sunlight reflector. The solar light reflection device of this embodiment is suitably used for condensing sunlight in solar thermal power generation. The sunlight reflecting device of this embodiment has a sunlight reflector and a holding member that holds the sunlight reflector.

As a preferred embodiment, when the solar reflective device is used for solar thermal power generation, a cylindrical member having a fluid inside is provided as a heat collecting part in the vicinity of the solar reflective film (film mirror) 10, and sunlight is applied to the cylindrical member. The internal fluid is heated by reflecting the water, and the heat energy is converted to generate electricity to generate power. Moreover, the form called a tower type | mold is also mentioned as another form. The tower-type configuration has at least one heat collecting part and at least one solar power solar reflection device for reflecting sunlight and irradiating the heat collecting part, and is collected in the heat collecting part. There is one that uses liquid heat to heat a liquid and turn a turbine to generate electricity. In addition, it is preferable that a plurality of solar power generation solar reflective devices are arranged around the heat collection unit. Moreover, it is preferable that a plurality of solar reflective devices for solar thermal power generation are arranged concentrically or in a concentric fan shape. In addition, the sunlight is reflected by the sunlight reflector (sunlight reflecting mirror) installed around the support tower, then reflected by the collector mirror, and then further reflected by the collector mirror and sent to the heat collector. And sent to a heat exchange facility. The solar light reflection device of this embodiment can be used for both trough type and tower type. Of course, it can be used for various other types of solar thermal power generation.

The sunlight reflecting device has a holding member that holds the sunlight reflector. The holding member is preferably held in a state where the sunlight reflector can track the sun. Although there is no restriction | limiting in particular as a form of a holding member, For example, the form which hold | maintains several places with a rod-shaped holding member so that a sunlight reflector can hold | maintain a desired shape is preferable. The holding member preferably has a configuration for holding the solar reflector in a state where the sun can be tracked. However, when tracking the sun, the holding member may be driven manually, or a separate driving device may be provided to automatically provide the sun. It is good also as a structure to track.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

[Preparation of coating solution]
(Preparation of coating liquid L1 for low refractive index layer)
While 75 parts by mass of methyl ethyl ketone is heated and stirred at 45 ° C., 0.5 part by mass of hindered amine light stabilizer LA-52 (manufactured by ADEKA Co., Ltd.) is added, and acrylic polymer (BR-85: Mitsubishi Rayon) is added. 20 parts by mass of Delpet SRB215 (manufactured by Asahi Kasei Chemicals Co., Ltd.) and 4.5 parts by mass of Delpet SRB215 (manufactured by Asahi Kasei Chemicals Corporation) were added to prepare a coating solution L1 for a low refractive index layer.

The refractive index of the low refractive index layer obtained from the coating liquid L1 for low refractive index layer was 1.49. In addition, the measurement of refractive index was described below.

(Preparation of coating liquid L2 for low refractive index layer)
While heating and stirring 10 parts by weight of 3% by weight boric acid aqueous solution at 45 ° C., 80% by weight of 5% by weight aqueous solution of polyvinyl alcohol (PVA-235, polymerization degree 3500, saponification degree 88 mol%, manufactured by Kuraray Co., Ltd.) 1 part by weight of a 1% by weight aqueous solution of a surfactant (Lapisol A30, manufactured by NOF Corporation) was added, and 9 parts by weight of pure water was added to prepare a coating solution L2 for a low refractive index layer. .

The refractive index of the low refractive index layer obtained from the coating liquid L2 for low refractive index layer was 1.50. In addition, the measurement of refractive index was described below.

(Preparation of coating liquid L3 for low refractive index layer)
As inorganic oxide fine particles 111a, colloidal silica (Snowtex OS, manufactured by Nissan Chemical Industries, Ltd., solid content 20% by mass, average particle size 8-11 nm) 22.5 parts by mass, pure water 22.5 parts by mass, polyoxy After adding 10 parts by mass of a 5% by mass aqueous solution of an alkylene dispersant (Marialim AKM-0531, manufactured by NOF Corporation) and 10 parts by mass of a 3% by mass boric acid aqueous solution, respectively, while heating to 45 ° C. and stirring, Polyvinyl alcohol (JC-25 (polymerization degree 2500, saponification degree 99.5 mol%, manufactured by Nihon Acetate Bipoval Co., Ltd.)) and JM-17 (polymerization degree 1700, saponification degree 96.4 mol%, Nihon Acetate bipoval share) Made by company), JP-15 (degree of polymerization 1500, degree of saponification 89.8 mol%, manufactured by Nihon Acetate / Poval), JL-25E (degree of polymerization 2500, 40 mass parts of 5 mass% aqueous solution of 43: 5: 9: 43 (solid content mass ratio) with a degree of conversion of 79.5 mol%, manufactured by Nippon Vinegar Pover Co., Ltd.), surfactant (Lapisol A30) 1 part by weight of 1% by weight aqueous solution (manufactured by NOF Corporation) and 2 parts by weight of pure water were added to prepare a coating solution L3 for a low refractive index layer.

The refractive index of the low refractive index layer obtained from the coating liquid L3 for low refractive index layer was 1.45. In addition, the measurement of refractive index was described below.

(Preparation of coating liquid L4 for low refractive index layer)
After adding 10 parts by weight of a 3% by weight boric acid aqueous solution to 45 parts by weight of the 10% by weight fluoropolymer 1 aqueous solution obtained in the following preparation, while heating to 45 ° C. and stirring, polyvinyl alcohol (JC-25 ( JM-17 (polymerization degree 1700, saponification degree 96.4 mol%, manufactured by Nihon Acetate Bi-Poval Co., Ltd.), JP- 15 (polymerization degree 1500, saponification degree 89.8 mol%, manufactured by Nippon Vinegar Pover Co., Ltd.) and JL-25E (polymerization degree 2500, saponification degree 79.5 mol%, manufactured by Nihon Acetate Beverage Poval Co., Ltd.) , 43: 5: 9: 43 (mixture of solid content)) and 40 parts by mass of a 1% by mass aqueous solution of a surfactant (Lapisol A30, manufactured by NOF Corporation). ,Pure water The coating solution for low refractive index layer L4 was prepared by adding the parts by weight.

The refractive index of the low refractive index layer obtained from the coating liquid L4 for low refractive index layer was 1.40. In addition, the measurement of refractive index was described below.

(Preparation of fluoropolymer 1 aqueous solution)
In a 1 L flask equipped with a reflux condenser under a nitrogen atmosphere, 6.4 g of 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate, 26.4 g of methoxypolyethylene glycol # 1000 methacrylate, and 34.9 g of methyl The methacrylate was added to a mixed solvent of 150 ml of isopropanol and 100 ml of pure water. After stirring at room temperature for 1 hour, 1.2 g of ammonium persulfate dissolved in 10 ml of pure water was added, and the mixture was heated and stirred at 65 ° C. for 16 hours. After cooling the obtained reaction mixture, isopropanol was distilled off with a rotary evaporator, and pure water was further added to prepare a 10% by mass aqueous solution containing a fluoropolymer 1. When the molecular weight was measured using GPC, the weight average molecular weight was 16,000.

(Preparation of silica-attached titanium dioxide sol)
After adding 2 parts by mass of pure water to 0.5 parts by mass of 15.0% by mass titanium oxide sol (SRD-W, volume average particle size 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Industry Co., Ltd.), Heated. Next, 1.3 parts by mass of an aqueous silicic acid solution (sodium silicate 4 (manufactured by Nippon Chemical Industry Co., Ltd.) diluted with pure water so that the SiO ₂ concentration becomes 2.0% by mass) was gradually added. Then, heat treatment was carried out at 175 ° C. for 18 hours in an autoclave, and after cooling, it was concentrated with an ultrafiltration membrane to adhere SiO ₂ to the surface (the coating amount of silicon-containing hydrate was 4% by mass) ) Titanium dioxide sol (hereinafter, silica-attached titanium dioxide sol) was obtained in a solid content concentration of 20% by mass.

(Preparation of coating liquid H1 for high refractive index layer)
45 parts by mass of silica-attached titanium dioxide sol (solid content 20.0% by mass) obtained as the inorganic oxide fine particles 112a in the above preparation was added to polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, 2 parts by weight of 5% by weight aqueous solution of Kuraray), 10 parts by weight of 3% by weight boric acid aqueous solution, and 10 parts by weight of 2% by weight citric acid aqueous solution, respectively, and then heated to 45 ° C. with stirring, polyvinyl alcohol ( 20 parts by weight of a 5% by weight aqueous solution of PVA-117, polymerization degree 1700, saponification degree 98.5 mol%, manufactured by Kuraray Co., Ltd., 1 part by weight of a 1% by weight aqueous solution of a surfactant (Lapisol A30, manufactured by NOF Corporation) And 12 parts by mass of pure water was added to prepare a coating solution H1 for a high refractive index layer.

The refractive index of the high refractive index layer obtained from the coating liquid H1 for the high refractive index layer was 1.95. In addition, the measurement of refractive index was described below.

(Preparation of coating liquid H2 for high refractive index layer)
As the inorganic oxide fine particles 252a, 30 parts by mass of zirconia sol (SZR-W, solid content 30% by mass, manufactured by Sakai Chemical Industry Co., Ltd., primary average particle size 3 nm), polyoxyalkylene dispersant (Marialim AKM-0531, JP 10 mass parts of 5 mass% aqueous solution (made by Yu Oil Co., Ltd.), 3 mass% boric acid aqueous solution 10 mass parts, and 2 mass% citric acid aqueous solution 10 mass parts in this order, and then heated to 45 ° C. while stirring, polyvinyl 20 parts by weight of a 5% by weight aqueous solution of alcohol (PVA-217, degree of polymerization 1700, degree of saponification 88.0 mol%, manufactured by Kuraray Co., Ltd.), 1% by weight aqueous solution 1 of a surfactant (Rapisol A30, manufactured by NOF Corporation) A mass part was added, and 19 parts by mass of pure water was added to prepare a coating solution H2 for a high refractive index layer.

The refractive index of the high refractive index layer obtained from the coating liquid H2 for high refractive index layer was 1.85. In addition, the measurement of refractive index was described below.

(Preparation of coating liquid H3 for high refractive index layer)
43 parts by mass of the silica-attached titanium dioxide sol (solid content 20.0% by mass) obtained as the inorganic oxide fine particles 262a, 55 parts by mass of the coating liquid L1 for the low refractive index layer, and UV absorber Tinuvin 479 (BASF) 2 parts by mass) was added, and the mixture was stirred for 2 hours while maintaining the solution temperature at 10 ° C. to prepare a coating solution H3 for a high refractive index layer.

The refractive index of the high refractive index layer obtained from the coating liquid H3 for the high refractive index layer was 1.90. In addition, the measurement of refractive index was described below.

[Production of solar reflective film]
(Preparation of silver vapor deposition film 10a)
A biaxially stretched polyester film (polyethylene terephthalate film, thickness 50 μm) was used as the resin film support 12. On one side of this film, a silver reflective layer 13 having a thickness of 80 nm was vacuum deposited as a silver reflective layer 13 at a deposition speed of 100 m / sec by vacuum deposition. On the silver reflective layer 13, a polyester resin (Polyester SP-181, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and a TDI isocyanate (2,4-tolylene diisocyanate) as a curing agent in a resin solid content ratio of 10: In the resin mixed in 2, an amount adjusted to 0.3 g / m ² after applying glycol dimercaptoacetate as a corrosion inhibitor is added, and coating is performed so that the film thickness becomes 0.1 μm by the gravure coating method. Thus, the first corrosion prevention layer 14a was obtained. Further, a water-dispersed emulsion type benzotriazole-based polymer type UV-absorbing coating solution UVA-1383MG (manufactured by BASF) is coated by a gravure coating method, dried at 55 ° C. for 4 minutes, and then a second 3 μm thick second The corrosion prevention layer 14b was formed and the silver vapor deposition film 10a was produced. Here, the first and second corrosion prevention layers 14 a and 14 b are combined to form the corrosion prevention layer 14.

(Measurement of water contact angle of corrosion prevention layer 14)
Based on JIS-R3257, 3 μL of pure water was dropped on the surface of the corrosion prevention layer. The contact angle of pure water was measured using a contact angle meter DM300 (Kyowa Interface Chemistry). The obtained results are shown in Table 1.

Comparative Example 1 (Preparation of solar reflective film 30A) (Sample 1; see FIG. 3)
A release film 16 coated with an acrylic pressure-sensitive adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide Industries Co., Ltd.) so as to have a film thickness of 25 μm was laminated on the surface of the corrosion prevention layer 14 of the silver deposited film 10a. Thus, the pressure-sensitive adhesive layer 15 was formed, and a solar reflective film 30A (Sample 1) of Comparative Example 1 was obtained.

Example 1 (Preparation of solar reflective film 10A) (Sample 2; see FIG. 4)
A release film 16 coated with an acrylic pressure-sensitive adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide Industries Co., Ltd.) so as to have a film thickness of 25 μm was laminated on the surface of the corrosion prevention layer 14 of the silver deposited film 10a. Thus, an adhesive layer 15 was formed. While maintaining the coating liquid H1 for the high refractive index layer at 45 ° C. as the high refractive index layer 112 on the surface opposite to the surface on which the silver reflective layer 13 of the polyester film film as the resin film support 12 is deposited, the low refractive index As the refractive index layer 111, the coating liquid L1 for the low refractive index layer is kept at 25 ° C. while keeping H1 and L1, H1 is in contact with the polyester film, and then L1 on H1 and H1 and L1. Are applied alternately, and the high refractive index layer 112 is dried by blowing hot air of 80 ° C. so that the dry film thickness is 46 nm, and the low refractive index layer 111 is 62 nm. The ultraviolet reflective laminated part 11 which consists of a low-refractive-index layer 10 layer and a high-refractive-index layer 11 layer) was formed, and 10 A (sample 2) of solar reflective films of Example 1 was obtained.

Example 2 (Preparation of solar reflective film 10B) (Sample 3; see FIG. 5)
The step of forming the silver reflection layer 13, the corrosion prevention layer 14, and the adhesive layer 15 (further, the release film 16) on the polyester film film that is the resin film-like support 12 is the sunlight reflection of the silver deposited film 10a and Example 1. It produced similarly to the process of the film 10A. The coating film H1 for the high refractive index layer as the high refractive index layer 112 and the low refractive index as the low refractive index layer 111 on the surface opposite to the surface on which the silver reflective layer 13 of the polyester film that is the resin film support 12 is deposited. Using a slide hopper coating apparatus capable of coating the layer coating liquid L3 with 21 layers, the low refractive index layer coating liquid L3 and the high refractive index layer coating liquid H1 were heated to 45 ° C. while being kept at 45 ° C. On the polyethylene terephthalate film (Toyobo Co., Ltd. A4300: film having a double-sided easy-adhesion layer) having a thickness of 50 μm which is the resin film-like support 12, H1 is in contact with the polyethylene terephthalate film, and then L3 and H3 Thus, simultaneous multi-layer coating was performed so that H1 and L3 were alternated. Immediately after the coating, 5 ° C. cold air is blown for 5 minutes, and then 80 ° C. hot air is blown to dry, so that the ultraviolet reflecting laminated portion 11 composed of 21 layers (low refractive index layer 10 layers, high refractive index layer 11 layers). And a solar reflective film 10B (sample 3) of Example 2 was obtained. Regarding the film thickness after drying, the low refractive index layer 111 coated with the low refractive index layer coating liquid L3 was 64 nm in each layer, and the high refractive index layer 112 coated with the high refractive index coating liquid H1 was 47 nm in each layer.

Comparative Example 2 (Preparation of solar reflective film 30B) (Sample 4; see FIG. 6)
A release film 16 coated with an acrylic pressure-sensitive adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide Industries Co., Ltd.) so as to have a film thickness of 25 μm is applied to the silver reflective layer of the polyester film film 12 of the silver deposited film 10a. The pressure-sensitive adhesive layer 15 was formed by laminating on the surface opposite to the surface on which 13 was deposited, and a solar reflective film 30B (sample 4) of Comparative Example 2 was obtained.

Comparative Example 3 (Production of Sunlight Reflecting Film 30C) (Sample 5; see FIG. 7)
The step of forming the silver reflection layer 13, the corrosion prevention layer 14, and the adhesive layer 15 (further, the release film 16) on the polyester film film that is the resin film-like support 12 is the sunlight reflection of the silver deposited film 10a and Example 1. It was produced in the same manner as the film 10A. An adhesive layer 18 (film thickness: 7 μm) was applied to the surface opposite to the surface on which the silver reflective layer 13 of the polyester film film as the resin film-like support 12 was deposited. The adhesive layer 18 was prepared by mixing LIS603 and CR-001 (both manufactured by Toyo Ink Co., Ltd.) at a ratio of 10: 1 and then applying an adhesive obtained by stirring for 1 hour while maintaining the liquid temperature at 25 ° C. The adhesive layer 18 was obtained by applying hot air at 30 ° C. for 30 seconds. An ultraviolet absorber-containing acrylic film (S001G, manufactured by Sumitomo Chemical Co., Ltd .; thickness 50 μm) was bonded to the adhesive layer 18 as an ultraviolet protective layer 19 to obtain a solar reflective film 30C (sample 5) of Comparative Example 3. .

Example 3 (Preparation of solar reflective film 10C) (Sample 6; see FIG. 8)
A release film 16 coated with an acrylic pressure-sensitive adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide Industries Co., Ltd.) so as to have a film thickness of 25 μm is dried on the silver reflective layer 13 of the polyester film 12 of the silver deposited film 10a. The pressure-sensitive adhesive layer 15 was formed by laminating on the surface opposite to the surface on which the material was deposited. A slide hopper capable of applying 21 layers of high refractive index layer coating liquid H1 as a high refractive index layer and 21 layers of low refractive index layer coating liquid L3 as a low refractive index layer on the side where the corrosion prevention layer 14 is formed on the silver deposited film 10a. Polyethylene terephthalate having a thickness of 50 μm, which is a resin film-like support 12 heated to 45 ° C. while keeping the coating solution L 3 for low refractive index layer and the coating solution H 1 for high refractive index layer at 45 ° C. using a coating apparatus. On the film (A4300 manufactured by Toyobo Co., Ltd .: film having a double-sided easy-adhesion layer), H1 is in contact with the polyethylene terephthalate film, and then L3 is formed on H1, and H1 and L2 are alternated. Thus, simultaneous multilayer coating was performed. Immediately after the coating, 5 ° C. cold air is blown for 5 minutes, and then 80 ° C. hot air is blown to dry, so that the ultraviolet reflecting laminated portion 11 composed of 21 layers (low refractive index layer 10 layers, high refractive index layer 11 layers). And a solar reflective film 10C (sample 6) of Example 3 was obtained. The film thickness after drying was 64 nm for each layer coated with the coating liquid L3 for low refractive index layer, and 47 nm for each layer coated with the coating liquid H1 for high refractive index.

Example 4 (Preparation of solar reflective film 10D) (Sample 7; see FIG. 9)
The following scratch-resistant layer curable hard coat solution was applied to the surface of the ultraviolet reflective laminate 11 of Example 3 to a dry film thickness of 3 μm and dried at 90 ° C. for 1 minute. Thereafter, the solar reflective film 10D (Sample 7) of Example 4 having a scratch-resistant layer 17 on the surface was placed for 7 days in a constant temperature environment of 45 ° C.

(Preparation of curable hard coat solution for scratch-resistant layer)
20 parts by weight of water and 2 parts by weight of acetic acid were placed in a synthesis container and stirred sufficiently while maintaining the liquid temperature at 0 to 10 ° C. In this, 50 parts by weight of trimethoxysilane (Kanto Chemical Co., Ltd .: the chemical formula is CH ₃ Si (OCH ₃ ) ₃ ), FAS (Shin-Etsu Chemical Co., Ltd .: KBM-7803) containing 0.5 wt. And the mixture was stirred for 16 hours while maintaining the liquid temperature at 10 ° C. Thereafter, the liquid temperature was set to 20 ° C., 0.1 part by weight of a silicone-based surface conditioner (BIC Chemie Japan Co., Ltd .: BYK-300 (organically modified polysiloxane)), 0.05 part by weight of sodium acetate, n- 15 parts by weight of propanol was contained to obtain a curable hard coat solution for a scratch-resistant layer.

Comparative Example 4 (production of solar reflective film 30D) (Sample 8; see FIG. 10)
An ultraviolet reflective film 30D (sample 8) was produced by the same production method as in Example 6 described in JP-T-2011-521289.

The ultraviolet reflective film 21 was formed of two types of polymer layers of PMMA and fluoropolymer available as trade name 3M (registered trademark) Dyneon (registered trademark) Fluoroplastic THVP 2030GZ. PMMA layer 212 and THV layer 211 were alternately stacked and coextruded through a multilayer polymer melt manifold to form a multilayer melt stream having 150 alternating layers of two polymer layers. In addition, a pair of

non-optical layers

231, 232 made of PEN can be coextruded on either side of the optical stack as a protective surface layer 23. This multilayer coextrusion melt stream was cast onto a chill roll at 22 meters per minute to form a multilayer molded web about 300 micrometers thick. Next, the multilayer molded web was heated at 135 ° C. for 10 seconds in a tenter oven and biaxially oriented with respect to a stretch ratio of 3.8 × 3.8 to obtain a heat stretched ultraviolet reflective film 11. These PMMA thin films contain 2% by weight of an ultraviolet absorber available as the product Tinuvin 405.

On one surface of this heat-stretched ultraviolet reflective film 11, a silver reflective layer 13 having a thickness of 80 nm was vacuum deposited as a silver reflective layer 13 by a vacuum deposition method at a deposition speed of 100 m / sec. On the silver reflective layer 13, a polyester resin (Polyester SP-181, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and a TDI isocyanate (2,4-tolylene diisocyanate) as a curing agent in a resin solid content ratio of 10: In the resin mixed in No. ² , an amount adjusted to 0.3 g / m ² after applying glycol dimercaptoacetate as a corrosion inhibitor is added and coated to a thickness of 0.1 μm by the gravure coating method. It was set as the corrosion prevention layer 14a. Further, a water-dispersed emulsion type benzotriazole polymer type UV absorbing coating solution UVA-1383MG (manufactured by BASF) is coated by a gravure coating method, dried at 55 ° C. for 4 minutes, and a corrosion prevention layer having a thickness of 3 μm. 14b was formed. The corrosion prevention layers 14a and 14b are combined to form the corrosion prevention layer 14. A release film 16 coated with an acrylic pressure-sensitive adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide) so as to have a film thickness of 25 μm after drying is laminated on the surface of the corrosion prevention layer 14 of the silver vapor-deposited film, and the pressure-sensitive adhesive layer 15 And a solar reflective film 30D of Comparative Example 4 (Sample 8) was obtained.

Comparative Example 5 (Preparation of solar reflective film 30E) (Sample 9; see FIG. 11)
The process of forming the adhesion layer 15 (further peeling film 16) on the polyester film 12 was produced in the same manner as the solar reflective film 10A of Example 1.

The coating liquid H2 for the high refractive index layer as the high refractive index layer and the low refractive index layer as the low refractive index layer on the opposite side of the surface of the polyester film 12 that is the resin film support 12 on which the silver reflective layer 13 is deposited. Using a slide hopper coating apparatus capable of applying 21 layers of coating liquid L2 for coating, the thickness of the coating liquid L2 for low refractive index layer and the coating liquid H2 for high refractive index layer heated to 45 ° C. while being kept at 45 ° C. On a polyethylene terephthalate film (Toyobo A4300: film having a double-sided easy-adhesion layer) having a thickness of 50 μm so that H2 is in contact with the polyethylene terephthalate film, and then L3 on H2, and H2 and L2 are respectively Simultaneous multilayer coating was performed so as to alternate. Immediately after the coating, 5 ° C. cold air was blown for 5 minutes, and then 80 ° C. hot air was blown to dry to form an infrared reflecting layer 25 composed of 21 layers. The thickness of the infrared reflective layer 25 after drying was 180 nm for each layer 251 coated with the coating liquid L2 for low refractive index layer and 150 nm for each layer 252 coated with the coating liquid H2 for high refractive index.

Further, on the infrared reflective layer 25, a slide hopper coating apparatus capable of coating 21 layers of the high refractive index layer coating liquid H3 as the high refractive index layer and the low refractive index layer coating liquid L4 as the low refractive index layer is used. A 50 μm thick polyethylene terephthalate film (Toyobo Co., Ltd.), which is a resin film-like support 12 heated to 45 ° C. while keeping the refractive index layer coating solution L 4 and the high refractive index layer coating solution H 3 at 45 ° C. A4300: Double-sided easy-adhesive layer) On the surface of the infrared reflective layer 25, L4 is in contact with the surface of the infrared reflective layer 25, then H3 is on L4, and H3 and L4 are alternately Simultaneous multi-layer coating was performed. Immediately after the coating, 5 ° C. cold air was blown for 5 minutes, and then 80 ° C. hot air was blown to dry to form a 21-ray visible light reflecting layer 26. The thickness of the visible light reflecting layer 26 after drying was 120 nm for each layer 261 coated with the coating liquid L4 for low refractive index layer, and 90 nm for each layer 262 coated with the coating liquid H3 for high refractive index.

Further, using a slide hopper coating apparatus capable of coating 21 layers of the high refractive index layer coating liquid H1 as the high

refractive index layer

112 and 21 layers of the low refractive index layer coating liquid L3 as the low refractive index layer 111, the coating for the low refractive index layer is performed. A 50 μm thick polyethylene terephthalate film (A4300 manufactured by Toyobo Co., Ltd .: double-sided easy adhesion) which is a resin film-like support 12 heated to 45 ° C. while keeping the liquid L3 and the coating solution H1 for the high refractive index layer at 45 ° C. L3 is formed on the surface of the infrared ray reflection layer 25 and the visible ray reflection layer 26 formed in order on the layer), so that L3 is in contact with the surface of the visible ray reflection layer 26, and then H1 on L3, and H1 Simultaneous multi-layer coating was performed so that L3 alternated. Immediately after coating, 5 ° C. cold air was blown for 5 minutes, and then 80 ° C. hot air was blown to dry to form an ultraviolet reflecting laminated portion 11 composed of 21 layers. Regarding the film thickness after drying, the low refractive index layer 111 coated with the low refractive index layer coating liquid L3 was 64 nm in each layer, and the high refractive index layer 112 coated with the high refractive index coating liquid H1 was 47 nm in each layer. In this way, a solar reflective film 30E (Sample 9) of Comparative Example 5 was obtained.

Comparative Example 6 (production of solar reflective film 30F) (Sample 10; see FIG. 12)
The process up to the step of forming the visible light reflection layer 26 was the same as the method for manufacturing the solar reflective film 30E of Comparative Example 5. An adhesive layer 27 (thickness 5 μm) is applied to the surface of the visible light reflection layer 26, and the ultraviolet reflection laminated portion 11 of Comparative Example 4 prepared in advance is laminated, so that the solar reflective film 30 F (Sample 10) of Comparative Example 6 is laminated. Obtained.

[Evaluation of solar reflective film]
The following performance evaluation was performed on each of the solar reflective films (samples 1 to 10) produced above.

(Measurement of single film refractive index of each layer)
In order to measure the refractive index on the substrate, a sample in which each layer was applied as a single layer was prepared. After cutting this sample into 10 cm × 10 cm, the refractive index was determined according to the following method. Using Hitachi spectrophotometer U-4100 (solid sample measurement system), the surface opposite to the measurement surface (back surface) of each sample is roughened and then light absorption is performed with a black spray. Then, the reflection of light on the back surface was prevented, the reflectance at 550 nm was measured under the condition of regular reflection at 5 degrees, the average value was obtained, the average reflectance was obtained from the result, and the refractive index was further obtained.

(Initial 5 degree specular reflectance measurement)
The transmittance of each of the solar reflective films prepared above and the 5 degree regular reflectance on the light incident surface side were measured. The spectrophotometer U-4100 (solid sample measurement system) manufactured by Hitachi was used for the measurement. The reflectance wavelength range was 280-2500 nm. The average reflectance R (wavelength 280 to 2500 nm) calculated from the measured values in the reflectance wavelength range 280 to 2500 nm was ranked as follows.

5: 95% or more 4: 90% or more and less than 95% 3: 85% or more and less than 90% 2: 80% or more and less than 85% 1: less than 80%.

(Curl evaluation)
The curl of the film was measured by using the curl measurement template of Method A in “Measuring Method of Curling of Photographic Film” of JIS K7619-1988. Here, the curl plus (+) means a curl where the light incident side of the film is inside the curve, and the minus (−) means a curl where the light incident side is outside the curve. The curl is expressed by the following mathematical formula.

According to the curl amount of the measurement result, it was ranked as follows:
5: -5 or more to +5 or less 4: -10 or more to less than -5, more than +5 to less than +10 3: -15 or more to less than -10, more than +10 to less than +15 2: -20 or more to less than -15, more than +15 ~ + 20 or less 1: less than −20, more than +20.

(Evaluation of weather resistance)
After each of the produced solar reflective films was left for 30 days in an environment of a temperature of 85 ° C. and a relative humidity of 85%, the light incident surface side of the film was irradiated with a xenon lamp (using a suga tester SX75, a black panel (Radiation intensity 180 W / m ² , 5000 hours) in an environment of a temperature of 63 ° C. and a relative humidity of 50%. Subsequently, after the xenon lamp irradiation, the regular reflectance of 5 degrees was measured by the same method as described above, the initial reflectance was compared with the reflectance after the weather resistance test, and the film was evaluated according to the following evaluation. Reflectance after weathering test was the reflectance upon reaching ultraviolet integrated light amount 3450 mJ / ^{m 2} as "UV3450MJ / ^{m 2} after exposure", the reflectance at the time it reaches the ultraviolet integrated light amount 6900MJ / ^{m 2} “After UV6900 MJ / m ² exposure”.

-Decrease in maximum reflectivity after the weather resistance test with respect to the initial maximum reflectivity (= initial maximum reflectivity-maximum reflectivity after the weather resistance test (%))
5: Maximum reflectivity decrease is less than 10% 4: Maximum reflectivity decrease is 10% or more and less than 30% 3: Maximum reflectivity decrease is 30% or more and less than 50% 2: Maximum reflectivity decrease is 50% or more and less than 70% 1 : Maximum reduction in reflectance is 70% or more.

(Evaluation of adhesion)
After the above weather resistance evaluation, a cross-cut test based on JIS K 5600-5-6: 1999 was performed. Specifically, 11 cuts were made vertically and horizontally at intervals of 1 mm on the light incident surface side of each sunlight reflecting film to produce 100 1 mm square grids. A cellophane tape was affixed thereon, quickly peeled off at an angle of 90 degrees, and the number of grids remaining without being peeled was measured. According to the following criteria, in Comparative Example 1, the silver reflective layer and the resin film-like support, In Examples 1 and 2, an ultraviolet reflecting part and a resin film-like support, in Comparative Example 2 a silver reflecting layer (or corrosion prevention layer) and a resin film-like support, and in Comparative Example 3 a resin film via an ultraviolet protective layer and an adhesive layer In Example 3, the silver reflective layer via the UV reflective laminate and the corrosion prevention layer was used in Example 3, the UV reflective laminate and the scratch-resistant layer were used in Example 4, and the heat-stretched UV reflective film and the silver reflective were used in Comparative Example 4. In Comparative Example 5, the evaluation of adhesion between the ultraviolet light reflection laminate and the visible light reflection layer was evaluated. In Comparative Example 6, the adhesion evaluation between the ultraviolet light reflection laminate and the visible light reflection layer via the adhesive layer was evaluated.

5: No separation is observed 4: The number of peeled grids is 1 or more and 5 or less 3: The number of peeled grids is 6 or more and 10 or less 2: Stripped grids The number is 11 or more and 20 or less. 1: The number of peeled grids is 21 or more.

(Evaluation of scratch resistance)
Using a friction and wear tester (Tribo Station TYPE: 32, moving speed 4000 mm / min.) Using Shinto Kagaku Co., Ltd. A load of ² was applied and the sample (the light incident surface side of each solar reflective film) was reciprocated 20 times over a length of 10 cm. The scratch resistance evaluation of each solar reflective film was evaluated according to the following criteria.

5: Scratches are not recognized at all 4: 1 cm or more scratches are 1 or more and 5 or less 3: 1 cm or more scratches are 6 or more and 10 or less 2: 1 cm or more The number of scratches is 11 or more and 20 or less. The number of scratches of 1: 1 cm or more is 21 or more.

Evaluation results are shown in Table 1 below. In addition, it can be said that it is favorable if the evaluation rank is 3 or more in each evaluation.

As is clear from the results in Table 1, all the weather resistance evaluations of Examples 1 to 4 are within the range of 4 to 5. This is considered to be the following reason.

In all the solar reflective films of Examples 1 to 4, good reflection efficiency, light resistance, and curl reduction were observed. In particular, in Examples 2, 3, and 4, the refractive index difference between the high refractive index layer and the low refractive index layer is obtained by including an inorganic oxide in both the high refractive index layer and the low refractive index layer constituting the ultraviolet reflective laminate. As a result of the large UV reflection efficiency, the light resistance was improved as compared with Example 1. In Example 3, the reflectance was improved without being affected by light absorption of the polyester film by providing an ultraviolet reflective layer on the corrosion prevention layer instead of the polyester film. In Example 4, the scratch resistance and adhesion were improved by providing the scratch resistant layer.

On the other hand, in Comparative Examples 1 to 3, since there is no ultraviolet reflecting layer, usable sunlight is reduced (average reflectance is low and light resistance is low), and durability (adhesion and scratch resistance) is low (PET is yellow). (Variation), it can be seen that the number of items with a weather resistance evaluation of 1-2 was increased. In Comparative Example 4, since the ultraviolet reflecting layer was formed by heat stretching, the oxidation deterioration was accelerated under the influence of the remaining radicals, so that the ultraviolet durability was poor and the weather resistance evaluation was 1-2. I know that there is. In Comparative Example 5, since a coating layer of infrared rays, visible rays, and ultraviolet rays was laminated on one side of the polyester film, curling occurred in one direction, and the curl evaluation was 1. In Comparative Example 6, since the infrared ray, visible ray, and coating layer were laminated on one side of the polyester film, and the ultraviolet reflecting layer was formed by heat stretching, curling occurred in one direction, and the curl evaluation and weather resistance evaluation were 1-2. It can be seen that there are items.

This application is based on Japanese Patent Application No. 2013-138156 filed on July 1, 2013, the disclosure of which is incorporated by reference as a whole.

10, 10 ', 10A-10D, 30A-30F Solar reflective film,
11 UV reflective laminate,
11a Inorganic oxide particles in the ultraviolet reflective laminate,
12 resin film-like support,
13 Silver reflection layer,
14 corrosion protection layer,
14a first corrosion prevention layer,
14b second corrosion prevention layer,
15 adhesive layer,
16 Release material (release film),
17 scratch-resistant layer,
18 adhesive layer,
19 UV protective layer,
21 multilayer optical film,
23 Protective surface layer,
25 Infrared reflective layer,
26 Visible light reflection layer,
27 adhesive layer,
100 sunlight,
111 low refractive index layer,
111a inorganic oxide particles in the low refractive index layer,
112 high refractive index layer,
112a inorganic oxide particles in the high refractive index layer,
211 THV layer,
212 PMMA layer,
A pair of non-optical layers comprising 231 and 232 PEN;
251 Infrared reflective layer low refractive index layer,
252 high refractive index layer of infrared reflection layer,
261 a low refractive index layer of a visible light reflection layer,
262 A high refractive index layer of a visible light reflection layer.

Claims

In order from the light incident surface, it has an ultraviolet reflective laminate formed by coating, and a silver reflective layer,
At least 1 layer of the said ultraviolet reflective lamination part contains at least 1 sort (s) of inorganic oxide, The sunlight reflective film characterized by the above-mentioned.
The ultraviolet reflective laminate includes at least one unit in which a high refractive index layer and a low refractive index layer are laminated,
The high refractive index layer and the low refractive index layer both contain at least one polyvinyl alcohol,
When the polyvinyl alcohol (A) having the highest content in the low refractive index layer is polyvinyl alcohol (A) and the polyvinyl alcohol having the highest content in the high refractive index layer is polyvinyl alcohol (B),
The solar reflective film according to claim 1, wherein the saponification degree of the polyvinyl alcohol (A) is different from the saponification degree of the polyvinyl alcohol (B).
The solar reflective film according to claim 1, wherein a corrosion prevention layer is provided on a surface of the silver reflective layer.
The solar reflective film according to claim 3, wherein a water contact angle of the corrosion prevention layer covering the silver reflective layer is less than 90 °.
The solar reflective film according to any one of claims 1 to 4, wherein a scratch-resistant layer is provided on the sunlight entrance side of the ultraviolet reflective laminate.
A solar reflector comprising the solar reflective film according to any one of claims 1 to 5.
A solar light reflection device comprising the solar light reflector according to claim 6.