JP2015090395A - Sunlight reflective film, and sunlight reflector and sunlight reflecting device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sunlight reflective film which is capable of efficiently reflecting sunlight and offers superior durability.SOLUTION: A sunlight reflective film of the present invention includes, in order from a light incident side, an ultraviolet blocking layer for partially blocking ultraviolet rays, an ultraviolet reflective laminate layer containing at least one type of inorganic oxide, and a silver reflective layer. The ultraviolet blocking layer has a light transmittance of 10% or less at a wavelength of 350 nm and 50% or greater at a wavelength of 370 nm.

Description

  The present invention relates to a sunlight reflecting film that can efficiently reflect sunlight and has excellent durability, and a sunlight reflector and a sunlight 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 metal-coated multilayer mirror including a reflective metal layer and a multilayer polymer film.

  Further, 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 so that ultraviolet light is reflected in the same direction as visible light and infrared light and collected in the light receiving part. A technique for forming a dielectric multilayer film (ultraviolet reflective layer) formed by laminating a refractive index material and a low refractive index material is disclosed. Since the laminated body having such an ultraviolet reflective layer and a metal vapor deposition film can reflect light in the ultraviolet to infrared region, sunlight can be effectively reflected.

US Pat. No. 6088163 European Patent Application No. 2204624

  The metal-coated multilayer mirror of Patent Document 1 and the laminate of Patent Document 2 can be used by efficiently reflecting ultraviolet rays contained in sunlight. However, although the solar reflective film by these techniques is excellent in the sunlight reflective efficiency, the further improvement of durability is calculated | required.

  Therefore, an object of the present invention is to provide a sunlight reflecting film that can efficiently reflect sunlight and has excellent durability. Another object of the present invention is to provide a sunlight reflector and a sunlight reflector that can efficiently reflect sunlight and have excellent durability.

  The present inventor has intensively studied to solve the above problems. As a result, a solar reflective film in which an ultraviolet blocking layer that blocks a part of ultraviolet rays, an ultraviolet reflective laminated portion including at least one inorganic oxide, and a silver reflective layer are arranged in this order from the light incident side. In the above, the light transmittance at a specific wavelength of the ultraviolet blocking layer is within a specific range, so that it is possible to reflect sunlight efficiently and to obtain a solar reflective film excellent in durability. As a result, the present invention has been completed.

  That is, the above object of the present invention is achieved by the following configuration.

1. In order from the light incident side, it has an ultraviolet blocking layer that blocks a part of ultraviolet rays, an ultraviolet reflecting laminated portion containing at least one inorganic oxide, and a silver reflecting layer,
The ultraviolet blocking layer has a light transmittance at a wavelength of 350 nm of 10% or less and a light reflection film at a wavelength of 370 nm of 50% or more.

  2. 1. The ultraviolet blocking layer comprises 2,4,6-tris (4-biphenylyl) -1,3,5-triazine or a derivative thereof. The solar reflective film as described in 2.

  3. 1. The ultraviolet shielding layer contains at least one of titanium oxide, zirconium oxide, and tungsten oxide. Or 2. The solar reflective film as described in 2.

4). The ultraviolet reflective laminate includes at least one unit in which a high refractive index layer and a low refractive index layer are laminated,
Both the high refractive index layer and the low refractive index layer 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),
1. The saponification degree of polyvinyl alcohol (A) and the saponification degree of polyvinyl alcohol (B) are different. ~ 3. The solar reflective film in any one of.

  5. Above 1. ~ 4. A solar reflector comprising the solar reflective film according to any one of the above.

  6). 5. above. A solar light reflection device having the solar light reflector described in 1.

  ADVANTAGE OF THE INVENTION According to this invention, sunlight can be reflected efficiently and the sunlight reflective film excellent in durability can be provided. Moreover, according to this invention, sunlight can be reflected efficiently and the sunlight reflector and sunlight reflecting device excellent in durability can be provided.

It is sectional drawing which represents typically one form of the sunlight reflective film which concerns on embodiment of this invention. It is sectional drawing which represents typically the other form of the sunlight reflective film which concerns on embodiment of this invention.

  Hereinafter, although the preferable form of this invention is demonstrated, the technical scope of this invention should be defined based on description of a claim, and is not restrict | limited only to the following forms.

  A first aspect of the present invention includes, in order from the light incident side, an ultraviolet blocking layer that blocks a part of ultraviolet rays, an ultraviolet reflecting laminated portion including at least one inorganic oxide, and a silver reflecting layer. The ultraviolet blocking layer provides a solar reflective film having a light transmittance of 10% or less at a wavelength of 350 nm and a light transmittance of 50% or more at a wavelength of 370 nm.

  The solar reflective film of the present invention is not only a silver reflective layer that reflects infrared to visible light, but also an ultraviolet reflective laminate containing at least one inorganic oxide in order to efficiently use light in the ultraviolet region. Has a part. However, the present inventor does not necessarily have sufficient durability for a solar reflective film having a layer containing at least one inorganic oxide, and reflects sunlight when exposed to sunlight for a long period of time. It has been found that the effect may be reduced.

  And when the above problems were studied, in the solar reflective film, as disclosed in Patent Document 2, an ultraviolet reflective laminated portion composed of a dielectric multilayer film obtained by laminating a high refractive index material and a low refractive index material was used. When it has, the knowledge that the tendency becomes remarkable was acquired.

  Based on such knowledge, the present inventor has provided an ultraviolet blocking layer on the light incident side of the ultraviolet reflecting laminated portion, and further, the transmittance of the ultraviolet blocking layer is as described above, and the light transmittance in a certain region is increased. It has been found that the durability can be improved by increasing the light transmittance and decreasing the light transmittance in a certain region, and as soon as the present invention has been achieved.

  The mechanism for exerting the operational effects of the above-described configuration of the present invention is presumed as follows.

  A solar reflective film is required to efficiently reflect light having an appropriate wavelength in the ultraviolet reflective laminate. Therefore, in order to increase the reflection efficiency of light having an appropriate wavelength, the ultraviolet reflection laminated portion adopts a configuration in which a large number of high refractive index layers and low refractive index layers are laminated. Here, in order to reflect ultraviolet rays efficiently by obtaining a significantly large refractive index difference between the high refractive index layer and the low refractive index layer constituting the ultraviolet reflective laminate, the high refractive index layer and the low refractive index At least one of the layers is formed using an inorganic oxide. However, when the inorganic oxide is irradiated with ultraviolet rays, the inorganic oxide exhibits a catalytic action, and as a result, the ultraviolet reflecting laminated portion is deteriorated. More specifically, the inorganic oxide and the appropriate resin (binder) constitute an ultraviolet reflection laminated portion. When the inorganic oxide included in the resin is irradiated with ultraviolet rays, the inorganic oxide becomes a catalyst. And a reaction for deteriorating the resin (binder) proceeds. In other words, by providing an ultraviolet reflective laminated portion containing an inorganic oxide, it is possible to effectively utilize light reflected in the ultraviolet region, while reflecting ultraviolet rays due to the catalytic action (photocatalytic action) of the inorganic oxide. It is considered that the deterioration of the laminated portion proceeds.

  Therefore, the present inventor can suppress the deterioration of the ultraviolet reflection laminated portion due to the catalytic action by providing the ultraviolet blocking layer having a specific transmittance on the light incident side from the ultraviolet reflective laminated portion. The present invention has been completed. More specifically, in the present invention, the ultraviolet ray blocking layer absorbs light having a wavelength (350 nm) that promotes the catalytic action of the inorganic oxide so that the light transmittance at the wavelength is 10% or less, and the ultraviolet ray is reflected. The amount of ultraviolet light having a wavelength of 350 nm (more preferably, the amount of ultraviolet light having a wavelength of 350 nm or less) reaching the laminated portion is reduced as much as possible. On the other hand, the light transmittance of the ultraviolet blocking layer at a wavelength of 370 nm is set to 50% or more in order to effectively utilize light having a wavelength of 370 nm or more, which is energetically useful when using solar power. The solar reflective film of the present invention having such a configuration has improved durability because the catalytic action of the inorganic oxide contained in the ultraviolet reflective laminate is suppressed, and not only in the visible to infrared region, It is assumed that light in some ultraviolet regions can be efficiently reflected. The present invention is not limited to the above mechanism.

  Hereinafter, an embodiment according to the solar reflective film of the present invention will be described. 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.

  In the present specification, “X to Y” indicating a range means “X or more and Y or less”, and “weight” and “mass”, “wt%”, “mass%”, and “part by weight”. And “parts by mass” are treated as synonyms. Unless otherwise specified, measurements such as operation and physical properties are performed under conditions of room temperature (20 ° C.) / Relative humidity 40 to 50%.

<Sunlight reflection film>
FIG. 1 is a cross-sectional view schematically showing one embodiment of a solar reflective film according to an embodiment of the present invention. A solar reflective film 10 shown in FIG. 1 includes an ultraviolet blocking layer 14, an ultraviolet reflective laminated portion 11 including at least one inorganic oxide 11a, and a silver reflective layer 13 in this order from the incident side of sunlight 100. Have.

  In the solar reflective film 10, the sunlight 100 passes through the ultraviolet reflective laminated portion 11 including the inorganic oxide 11 a and the resin 11 b from the ultraviolet blocking layer 14 side and enters the silver reflective layer 13 side as indicated by an arrow. To do. At this time, a part of the ultraviolet rays contained in the sunlight 100 (mainly light having a wavelength of 350 nm or less) is absorbed by the ultraviolet blocking layer 14, and ultraviolet rays and other wavelengths that are not absorbed by the ultraviolet blocking layer 14 are ultraviolet rays. The light passes through the reflective laminate 11 and the silver reflective layer 13. In this way, by providing the ultraviolet blocking layer 14, light having a wavelength (mainly light having a wavelength of 350 nm or less) that promotes the catalytic action of the inorganic oxide 11a on the ultraviolet reflecting laminated portion 11 including the inorganic oxide 11a. The amount of incident can be reduced. As a result, the deterioration of the ultraviolet reflecting laminated portion 11 is suppressed, and the solar reflective film 10 of the present invention has high durability without reducing the effect of reflecting sunlight even when exposed to sunlight for a long time. Can be held.

  The solar reflective film 10 of the present invention is provided with an ultraviolet reflective laminated portion 11 including an inorganic oxide 11a and a resin 11b, which is provided in order from the direction in which the sunlight 100 is incident, and the silver reflective layer 13, so that the infrared- Light in a wide wavelength range up to the ultraviolet range can be reflected. Furthermore, since the ultraviolet rays are reflected by the ultraviolet reflecting laminated portion 11 containing the inorganic oxide 11a, the ultraviolet rays are prevented from penetrating deeper than the ultraviolet reflecting laminated portion 11, and the deterioration of the solar reflective film 10 is suppressed. be able to.

  In the solar reflective film 10, the ultraviolet reflective laminated portion 11 including the inorganic oxide 11a and the resin 11b has a unit in which a low refractive index layer 111 and a high refractive index layer 112 are laminated, as will be described in detail below.

  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 112, a low refractive index layer 111,... The stacked portion 11 only needs to 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 particularly Not 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 sufficient that at least one inorganic oxide is included in at least one of the layers constituting the reflective laminated portion 11. At this time, if the high refractive index layer 112 includes the inorganic oxide 112a, the difference in refractive index between the low refractive index layer and the high refractive index layer becomes large, and the ultraviolet reflection efficiency at the interface can be increased. It is valid. Moreover, as shown in FIG. 1, the high refractive index layer 112 and the low refractive index layer 112 and the low refractive index layer 111 together contain inorganic oxides 112a and 111a, so that the high refractive index layer 112 and the low refractive index are formed. As a result of an increase in the refractive index difference of the layer 111 and an increase in ultraviolet reflection efficiency, sunlight can be reflected more efficiently. Such a tendency is the same in the embodiment of FIG.

  In the embodiment of the sunlight reflecting film 10 shown in FIG. 1, a resin film-like support (polymer film) 12 is disposed so as to support the ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13. Yes. That is, the ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13 are formed on one surface side (light incident surface side) of the resin film-like support 12.

  Further, an adhesive layer is provided on the other surface (opposite to the light incident surface) of the resin film-like support 12 for attachment to a support substrate (a constituent member of a solar reflector; not shown). 15 is arranged. 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.

  FIG. 2 is a cross-sectional view schematically showing another embodiment of the solar reflective film according to the embodiment of the present invention. Also in the sunlight reflecting film 10 ′ shown in FIG. 2, the ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11 including at least one inorganic oxide 11 a, and the silver reflecting layer 13 in this order from the incident side of the sunlight 100. Furthermore, in this embodiment, the hard coat layer 17 is disposed on the light incident surface side with respect to the ultraviolet blocking layer 14. By providing the hard coat layer 17 in this way, 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.

  1 and 2 are formed in the order of the ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13 from the light incident surface side, but differ in the presence or absence of the hard coat layer 17 ( Composition). However, any of the configurations (modes) shown in FIGS. 1 and 2 can effectively and effectively express the effects of the present invention. The solar reflective film 10 ′ shown in FIG. 2 has the same configuration as that of FIG. 1 except that the solar reflective film 10 ′ shown in FIG. . Therefore, the description of the overlapping part is omitted.

  The order of lamination of the ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13 is not changed, and the light transmittance relationship between the ultraviolet blocking layer 14 and the ultraviolet reflecting laminated portion 11 described in detail below is impaired. As long as there is no other layer, you may provide another layer between each layer (or part). For example, one or more corrosion prevention layers may be disposed between the silver reflection layer 13 and the ultraviolet reflection laminated portion 11 in order to prevent corrosion of silver constituting the silver reflection layer 13. Furthermore, an anchor coat layer (not shown) may be provided between the resin film-like support 12 and the silver reflecting layer 13. By providing the anchor coat layer, the adhesiveness between the resin film-like support 12 and the layer formed on the support can be improved.

  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.

[UV blocking layer 14]
The solar reflective film 10, 10 ′ of this embodiment essentially has the ultraviolet blocking layer 14 on the light incident surface side with respect to the silver reflective layer 13 and the ultraviolet reflective laminated portion 11. The ultraviolet blocking layer 14 may be a single layer or may be formed by laminating a plurality of layers. From the viewpoint of easily controlling the light transmittance within a desired range, a form in which a plurality of layers are laminated is preferable.

  The ultraviolet blocking layer 14 has a function of absorbing at least a part of wavelengths (light) in an ultraviolet region (a wavelength region of 280 nm to 370 nm mainly out of 280 to 400 nm) included in sunlight, and is light at a wavelength of 350 nm. The transmittance is 10% or less, and the light transmittance at a wavelength of 370 nm is 50% or more. At this time, the lower limit of the light transmittance at a wavelength of 350 nm is 0%, and the upper limit of the light transmittance at a wavelength of 370 nm is 100%.

  In other words, the ultraviolet blocking layer 14 has a function of absorbing light having a wavelength of 350 nm at a rate exceeding 90% and absorbing light having a wavelength of 370 nm at a rate of less than 50%. At this time, the upper limit of the absorptance at a wavelength of 350 nm is 100%, and the lower limit of the absorptance at a wavelength of 370 nm is 0%.

  In addition, the said light transmittance shall point out the light transmittance in the state which laminated | stacked all these several layers, when the ultraviolet shielding layer 14 is the form which laminated | stacked several layers.

  Furthermore, the light transmittance of the ultraviolet blocking layer 14 at a wavelength of 350 nm is preferably 8% or less, more preferably 6% or less, and particularly preferably 5% or less. Further, the light transmittance of the ultraviolet blocking layer 14 at a wavelength of 370 nm is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more. .

  The light transmittance in the ultraviolet region (280 to 400 nm) contained in sunlight can be measured by the method described in the examples. In the present specification, the light transmittance of the ultraviolet blocking layer 14 is a value measured by the method described in the examples.

  By providing the ultraviolet blocking layer 14 having the above light transmittance characteristics, most of the light having a wavelength of 350 nm is absorbed by the ultraviolet blocking layer 14. Therefore, since the amount of light having a wavelength of 350 nm reaching the ultraviolet reflection laminated portion 11 described in detail below is extremely reduced, the catalytic action of the inorganic oxide 11a included in the ultraviolet reflective laminated portion 11 can be effectively suppressed. it can. On the other hand, the ultraviolet blocking layer 14 transmits light having a wavelength of 370 nm that does not affect the catalytic action of the inorganic oxide 11a. As a result, the light having a wavelength of 370 nm reaches the ultraviolet reflecting laminated portion 11, and the light having the wavelength is reflected by the ultraviolet reflecting laminated portion 11. Therefore, according to the solar reflective film 10, 10 'of this embodiment, sunlight can be efficiently reflected and used.

  The ultraviolet blocking layer 14 may adopt any composition as long as it has the above light transmittance characteristics. For example, (I) a structure containing an organic compound having a specific absorption wavelength, (II) a specific It is preferable that any one of the structures including the inorganic oxide is included.

  Further, from the viewpoint of further improving the durability, it is more preferable that both layers having the configurations (I) and (II) are included. That is, in the present invention, the ultraviolet blocking layer 14 preferably includes a first ultraviolet blocking layer containing an organic compound having a specific absorption wavelength and a second ultraviolet blocking layer containing a specific inorganic oxide. . Thus, when the ultraviolet blocking layer 14 in the present invention includes the first ultraviolet blocking layer and the second ultraviolet blocking layer, each may be stacked one by one or more. Further, the number of the first ultraviolet blocking layers and the number of the second ultraviolet blocking layers are not necessarily the same, and one layer may be provided more than the other layer.

  The thickness of the ultraviolet blocking layer 14 is not particularly limited, but is preferably 1 to 50 μm, more preferably 2 to 30 μm, and more preferably 2 to 10 μm. If the thickness is 1 μm or more, the ultraviolet blocking layer 14 can sufficiently absorb ultraviolet rays, and further, the cracking of the ultraviolet blocking layer 14 due to stress can be prevented. Moreover, if it is 50 micrometers or less, sufficient flexibility can be maintained. When the ultraviolet blocking layer 14 includes the first ultraviolet blocking layer and the second ultraviolet blocking layer, it is preferable that the sum of the thicknesses of the plurality of layers is within the above range.

  The stacking order of the first ultraviolet blocking layer and the second ultraviolet blocking layer is not particularly limited, but from the light incident surface side, the second ultraviolet blocking layer (that is, the layer of the configuration (II)), the first ultraviolet blocking layer It is preferable to form in order of the blocking layer (that is, the layer of the configuration (I)). Furthermore, in this case, it is preferable that the second ultraviolet blocking layer is the outermost layer. As will be described later, the second blocking layer may include a resin having low reactivity with the inorganic oxide, and the same resin as that used in the hard coat (scratch resistant layer) can be used as the resin. Therefore, the second barrier layer also serves as a hard coat layer, and durability can be improved without providing a separate hard coat layer.

  Hereinafter, the configurations of (I) and (II) will be described in detail.

(I) Configuration including an organic compound having a specific absorption wavelength The ultraviolet blocking layer 14 of this embodiment includes a compound (organic compound) having a specific absorption wavelength in order to satisfy the above-described light transmittance characteristics. The ultraviolet blocking layer 14 preferably contains a resin (transparent resin) from the viewpoint of obtaining desired light transmittance and easily producing a large-area film.

  In this embodiment, the compound having a specific absorption wavelength with respect to the total mass of the ultraviolet blocking layer 14 is preferably contained in an amount of 0.1 to 10 parts by mass, and more preferably 1 to 10 parts by mass. If it is 0.1 mass part or more, the light of a specific wavelength range can fully be absorbed. On the other hand, by setting the amount to 10 parts by mass or less, it is possible to suppress bleed out (a phenomenon in which the additive emerges on the surface of the film (layer) over time) and to prevent deterioration of haze (cloudiness). it can.

  The thickness of the ultraviolet blocking layer 14 of this embodiment is not particularly limited, but is preferably 1 to 50 μm, more preferably 2 to 30 μm, and more preferably 2 to 10 μm. If the thickness is 1 μm or more, the ultraviolet blocking layer 14 can sufficiently absorb ultraviolet rays, and further, the cracking of the ultraviolet blocking layer 14 due to stress can be prevented. Moreover, if it is 50 micrometers or less, sufficient flexibility can be maintained. In the case where the ultraviolet blocking layer 14 is formed by laminating a plurality of layers, the sum of the thicknesses of the plurality of layers is preferably within the above range.

-Organic compound which has a specific absorption wavelength In this form, the compound contained in the ultraviolet-ray blocking layer 14 has an absorption maximum in a specific area | region. Specifically, a compound having an absorption maximum in the range of 280 to 340 nm is preferable. The absorption maximum wavelength (λmax) of the compound is more preferably in the range of 290 to 330 nm, and particularly preferably in the range of 300 to 320 nm. The full width at half maximum is preferably 40 to 100 nm, and more preferably 50 to 80 nm.

  Any compound can be used as the compound contained in the ultraviolet blocking layer 14 as long as it has the above-mentioned absorption characteristics. However, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine or its compound can be used. A derivative is preferred.

  Specifically, “2,4,6-tris (4-biphenylyl) -1,3,5-triazine or a derivative thereof” is a compound represented by the following general formula (1).

In the above formula, R _{1 to} R ₆ are each independently a hydroxy group, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or 2 to 20 carbon atoms. An alkynyl group, an alkoxy group having 1 to 20 carbon atoms, an ester group (—COOR ′: R ′ is an alkyl group having 1 to 20 carbon atoms), an amino group, a cyano group, or a nitro group. K, m, and p are integers of 0 to 5, and l, n, and q are integers of 0 to 4.

The halogen atom of R _{1 to} R ₆ is not particularly limited, and any of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be selected. Preferred are a fluorine atom, a chlorine atom and a bromine atom, and particularly preferred is a fluorine atom.

The alkyl group having 1 to 20 carbon atoms of R _{1 to} R ₆ may be linear, branched or cyclic. Examples of the alkyl group represented by R _{1 to} R ₆ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and iso. -Linear alkyl group such as amyl group, tert-pentyl group, neopentyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, cyclohexyl group, cyclohexane Examples thereof include cyclic alkyl groups such as a heptyl group and a cyclooctyl group. Among these, from the viewpoint of improving the solubility in a solvent when the ultraviolet blocking layer 14 is formed by coating (coating method), an alkyl group having 1 to 8 carbon atoms is preferable, and a methyl group, an ethyl group, An n-propyl group and an isopropyl group are more preferable, and a methyl group and an ethyl group are more preferable.

The alkenyl group having 2 to 20 carbon atoms of R _{1 to} R ₆ may be linear, branched or cyclic as long as it has one or more double bonds. For example, vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group and the like can be mentioned. Among these, in order to improve solubility in a solvent, those having 2 to 8 carbon atoms are preferable, alkenyl groups having 2 to 5 carbon atoms are more preferable, and vinyl groups and allyl groups are particularly preferable.

The alkynyl group having 2 to 20 carbon atoms of R _{1 to} R ₆ may be linear, branched or cyclic as long as it has one or more triple bonds. For example, an ethynyl group, a propargyl group, etc. are mentioned. Among these, in order to improve solubility in a solvent, those having 2 to 8 carbon atoms are preferable, alkynyl groups having 2 to 5 carbon atoms are more preferable, and ethynyl groups are particularly preferable.

The alkoxy group having 1 to 20 carbon atoms of R _{1 to} R ₆ may be linear, branched or cyclic. Examples of the alkoxy group of R _{1 to} R ₆ include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an n-octyloxy group, and a 2-ethylhexyloxy group. Among these, in order to improve the solubility with respect to a solvent, a C1-C8 thing is preferable, a C1-C5 alkoxy group is more preferable, and a methoxy group and an ethoxy group are especially preferable.

About R < ₁ > -R < ₆ > ester group (-COOR '), since R' is the same as that of the said alkyl group of R < ₁ > -R < ₆ >, the description is abbreviate | omitted, but improves the solubility with respect to a solvent. Therefore, R ′ is preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

The amino group of R _{1 to} R _{6 is} a group represented by —NH ₂ , —NHR ″ or —NR ″ ₂ . R ″ is selected from an alkyl group having 1 to 20 carbon atoms. R ″ is the same as the description of the alkyl group of R _{1 to} R ₆ above, and thus the description thereof is omitted. R ″ is preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

k, l, m, n, p, and q represent the number of R _{1 to} R ₆ groups bonded to the benzene ring, respectively, k, m, and p are integers of 0 to 5, l, n, q is an integer of 0-4. In order to improve solubility in a solvent, k, m, and p are preferably 0 to 3, more preferably 0 to 1, l, n, and q are preferably 0 to 2, and 0 or 1 is more preferable.

  The compound represented by the general formula (1) may be used alone or in the form of a mixture of two or more.

・ Resin (transparent resin)
In this embodiment, the ultraviolet blocking layer 14 contains a transparent resin together with the above compound. In this specification, “the resin is transparent” indicates that the light transmittance of visible light (400 to 700 nm) is 80% or more.

  The transparent resin contained in the ultraviolet blocking layer 14 of this embodiment is not particularly limited, but is preferably excellent in light resistance, and specifically, a resin containing no aromatic ring in the main chain is preferable. It is more preferable that the resin is composed of a monomer component that does not have any. Moreover, as a transparent resin, since the ultraviolet blocking layer 14 is formed by coating from the viewpoint of productivity, it is preferable that the transparent resin has good dispersibility in a solvent together with the compound having the specific absorption wavelength. Examples of such resins include acrylic resins, olefin resins, vinyl chloride resins, acrylic / urethane resins, and fluorine-containing polymers.

  Further, the transparent resin is preferably a resin soluble in at least one of water and a solvent compatible with water (sometimes referred to as “water-soluble resin” in this specification). By including such a specific resin, the ultraviolet reflection laminated portion 11 can be produced in a large area and can be produced in a short time. That is, the resin is preferably a water-soluble resin from the viewpoint that aqueous coating can be used to form the ultraviolet blocking layer 14 by coating.

  In the present specification, the term “solvent having compatibility with water” refers to a solvent that 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 its chemical structure. Means. In addition, “resin soluble in at least one of water and 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.

  Although there is no restriction | limiting in particular in the weight average molecular weight of water-soluble resin, 1000-200000 are preferable and 3000-40000 are more preferable from a viewpoint which adjusts and manufactures the viscosity which can be coated. 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 PO 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.

  Examples of the water-soluble resin include polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, or acrylic acid-acrylic ester copolymer. Acrylic resins such as coalescence, polyvinyl alcohol (PVA), styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic Styrene acrylic acid resin such as acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer, Styrene-2-hydroxyethyla Chryrate-potassium styrenesulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-maleic acid Synthetic water-soluble resins such as ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and their salts; natural products such as gelatin and thickening polysaccharides Water-soluble resin etc. are mentioned. Among these, acrylic resins are preferable from the viewpoint of weather resistance.

  Examples of the monomer constituting the acrylic resin contained in the water-soluble resin include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, One or more kinds selected from monomers having no functional group in the side chain (hereinafter referred to as non-functional monomers) such as alkyl (meth) acrylates such as butyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl methacrylate. One type selected from monomers such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid, and itaconic acid. Monomers others having functional group such as OH or COOH in the side chain of two or more monomers (hereinafter, referred to as functional monomers) may be combined with one or more of.

  The monomer can be copolymerized by a known polymerization method such as a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, or a bulk polymerization method. Moreover, the weight average molecular weight obtained by this is 40,000-1 million, Preferably it is 100,000-400,000.

  Commercially available acrylic resins may be used, for example, BR-85 manufactured by Mitsubishi Rayon, Delpet SRB215 manufactured by Asahi Kasei Chemicals, and the like.

  In addition, said resin may be used individually or may be used in mixture of 2 or more types.

(II) Configuration Containing Inorganic Oxide The ultraviolet blocking layer 14 of this embodiment contains a specific inorganic oxide in order to satisfy the above light transmittance characteristics. The ultraviolet blocking layer 14 preferably contains a resin (transparent resin) from the viewpoint of obtaining desired light transmittance and easily producing a large-area film. In this embodiment, the material used for blocking (absorbing) ultraviolet rays is different from the above (I). In addition, due to such a difference in material, the type of resin that can be included in the ultraviolet blocking layer 14 may be different from that in the above (I).

  In this embodiment, the specific inorganic oxide is preferably contained in an amount of 1 to 20 parts by mass, more preferably 2 to 10 parts by mass with respect to the total mass of the ultraviolet blocking layer 14. If it is 1 mass part or more, the light of a specific wavelength range can fully be absorbed. On the other hand, by setting it as 20 mass parts or less, bleeding out can be suppressed and haze (cloudiness) deterioration can be prevented.

  The thickness of the ultraviolet blocking layer 14 of this embodiment is not particularly limited, but is preferably 1 to 50 μm, more preferably 2 to 30 μm, and more preferably 2 to 10 μm. If the thickness is 1 μm or more, the ultraviolet blocking layer 14 can sufficiently absorb ultraviolet rays, and further, the cracking of the ultraviolet blocking layer 14 due to stress can be prevented. Moreover, if it is 50 micrometers or less, sufficient flexibility can be maintained. In the case where the ultraviolet blocking layer 14 is formed by laminating a plurality of layers, the sum of the thicknesses of the plurality of layers is preferably within the above range.

-Inorganic oxide In this form, as the inorganic oxide contained in the ultraviolet blocking layer 14, the light transmittance of the ultraviolet blocking layer 14 at a wavelength of 350 nm is 10% or less, and the light transmittance at a wavelength of 370 nm is 50% or more. The metal oxide is not particularly limited as long as it can be used. For example, a metal oxide can be used, and among these, at least one of titanium oxide, zirconium oxide, and tungsten oxide is preferably included. More specifically, it preferably contains at least one of titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ), and tungsten oxide (WO ₃ ).

  The inorganic oxide efficiently absorbs light having a wavelength of 350 nm, but has high light transmittance at a wavelength of 370 nm, and thus is suitably used for the ultraviolet blocking layer 14 of the present invention. From the viewpoint of wavelength selectivity, titanium oxide is particularly preferable.

  The inorganic oxide is preferably a particle having an average particle diameter of 1 to 50 nm so that a desired transmittance can be obtained in the ultraviolet blocking layer 14. 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 particle image appearing on the cross section or surface of the ultraviolet blocking layer 14. This is a value obtained by measuring the particle size of 1000 arbitrary particles by the method of observing with an electron microscope.

・ Resin (transparent resin)
As described above, in the present embodiment, while the ultraviolet blocking layer 14 includes an inorganic oxide, these inorganic oxides absorb light having a wavelength of 350 nm, and at the same time, the photocatalytic action causes the binder resin present in the surroundings to be absorbed. May deteriorate. Therefore, in this embodiment, the resin used for forming the ultraviolet blocking layer 14 is preferably a transparent resin that is not affected by the catalytic action of the inorganic oxide. Furthermore, since the transparent resin used in this embodiment forms the ultraviolet blocking layer 14 by coating from the viewpoint of productivity, it is preferable that the transparent resin has good dispersibility in the solvent together with the inorganic oxide.

  Such a transparent resin is not particularly limited, and examples thereof include polymer materials typified by polysiloxane. Of these, the same material (silicone resin) as that used for the polysiloxane hard coat (scratch resistant layer) is preferably used. Therefore, in the case where an ultraviolet blocking layer composed of the structure (II) containing a specific inorganic oxide is provided, it can also serve as a hard coat layer.

Polysiloxane (silicone resin) are those represented by the general formula _A r Si (OA _{') s} is the starting material. A and A ′ represent an alkyl group having 1 to 10 carbon atoms, and r and s are integers satisfying the relationship r + s = 4 (where s is an integer of 1 to 4). Specifically, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, Tetra-tert-butoxysilane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltriethoxy Silane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethyl Le propoxysilane, dimethyl-butoxy silane, dimethyl dimethoxy silane, dimethyl diethoxy silane, hexyl trimethoxy silane and the like.

  Further, in the formation of the resin (transparent resin) constituting the ultraviolet blocking layer 14, 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-chloropropyltrilymethoxysilane, hexamethyldisilazane, vinyltris (β-methoxyethoxy) silane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride Rye It can also be used. Those having a hydrolyzable group such as methoxy group or ethoxy group substituted with a hydroxyl group are generally referred to as polyorganosiloxane, and are suitably used for the ultraviolet blocking layer 14 of this embodiment. By applying this on a substrate and curing by heating, the dehydration condensation reaction is accelerated, and by curing and crosslinking, the ultraviolet blocking layer 14 is formed. Among these polyorganosiloxanes, those having a methyl group as the organic group that is not eliminated by hydrolysis have the highest weather resistance. In addition, in the case of a methyl group, the methyl group is uniformly and densely distributed on the surface after the ultraviolet blocking layer 14 is formed, so that the falling angle is also low. Therefore, in this application, it is preferable to use methylpolysiloxane.

  Specific examples of materials used for the ultraviolet blocking layer 14 include Surcoat Series (manufactured by Doken), SR2441 (Toray Dow Corning), KF-86 (Shin-Etsu Silicone), Perma-New (registered trademark) 6000 (California Hardcoating). Company) or the like can be used.

(Method for forming ultraviolet blocking layer 14)
In any of the forms (I) and (II), the method for forming the ultraviolet blocking layer 14 is not particularly limited, and includes, for example, an organic compound (or inorganic oxide) having the specific absorption wavelength and a transparent resin. Examples thereof include a method of coating the composition for forming an ultraviolet blocking layer (coating solution) by coating with a wire bar, spin coating, dip coating, and the like, and a dry film forming method such as vapor deposition. Moreover, it is also possible to apply | coat and film-form the said composition (coating liquid) with continuous application apparatuses, such as a die coater, a gravure coater, and a comma coater.

  The composition (coating liquid) may contain a solvent, or may be appropriately diluted as necessary. Examples of the solvent contained in the coating solution include water, hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone). , Esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents can be appropriately selected or mixed for use. Among these, from the viewpoint of productivity, it is particularly preferable to use water and a solvent compatible with water.

  After coating the coating solution containing the solvent, the formed coating film is preferably dried at 30 ° C. or higher. For example, it is preferable to dry in the range of wet bulb temperature 5-50 degreeC and film surface temperature 5-100 degreeC (preferably 10-95 degreeC), and it is more preferable to dry at 40-90 degreeC. Further, the drying method is not particularly limited, and for example, warm air drying, infrared drying, and microwave drying are used. Among them, warm air drying is preferable. The drying time is preferably 0.5 to 10 minutes and more preferably 1 to 5 minutes from the viewpoint of productivity.

  Further, when a silicone resin is used as the resin constituting the ultraviolet blocking layer 14, after application, the solvent is dried, and then the curing / crosslinking of the resin is promoted, so that the temperature is 50 ° C. or higher and 150 ° C. or lower. It is preferable to perform heat treatment for minutes to several days. 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 treat at 40 ° C. to 80 ° C. for 2 days or more.

  The conditions of the coating and drying method are not particularly limited, but when the ultraviolet blocking layer 14 is composed of a plurality of layers, for example, a sequential coating method, a simultaneous multilayer coating method, or the like can be used.

  In the case of using the sequential coating method, first, the silver reflection layer 13 and the ultraviolet reflection laminate 11 and other optional layers are formed on one surface of the resin film-like support 12, and then the ultraviolet reflection laminate is formed. One coating solution containing the specific organic compound (or inorganic oxide) is applied onto the portion 11 (or other layer optionally provided) and dried. Further, another coating solution for forming a layer to be laminated next is applied on the coating film made of the one coating solution and dried to form a laminated film. Further, a multilayer film is obtained by repeating sequential application and drying by the above method until the number of layers necessary to develop a desired light transmittance is reached. At this time, since the drying conditions are the same as those in the case of the single layer described above, detailed description thereof is omitted.

  When performing simultaneous multi-layer coating, a plurality of types of coating liquids are heated to 30 to 60 ° C., and a plurality of types of coating liquids are simultaneously coated on the ultraviolet reflective laminate 11 (or other layers optionally provided). After the above, it is preferable that the temperature of the formed coating film is preferably cooled (set) to 1 to 15 ° C. and then dried at 10 ° C. or higher. More preferable drying conditions are a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10 to 90 ° C. Also, the drying method is not particularly limited, and the same method as described above is used, and among these, hot air drying is preferable.

  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.

(Other additives)
In any of the forms (I) and (II), various additives such as a plasticizer and a coating aid can be used as necessary. Hereinafter, although the additive which may be contained in the ultraviolet shielding layer 14 is demonstrated, it is not limited to these.

Plasticizer Plasticizers that can be included in the ultraviolet blocking layer 14 include, for example, organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, organic phosphate plasticizers, and organic phosphorous acid plastics. Examples thereof include phosphoric acid plasticizers, and the plasticizer is preferably a liquid plasticizer.

  The organic ester plasticizer is not particularly limited, and conventionally known plasticizers can be used. For example, triethylene glycol-di-2-ethylbutyrate, triethylene glycol-di-2-ethylhexanoate, triethylene Examples include glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, dibutyl sebacate, oil-modified sebacic acid alkyd, a mixture of phosphate ester and adipic acid ester, and the like.

  The phosphate plasticizer is not particularly limited, and examples thereof include tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphate, and the like.

-Coating aid As a coating aid which may be contained in the ultraviolet blocking layer 14, for example, a siloxane surfactant can be used.

  These siloxane-based surfactants can be obtained as commercially available products, such as BYK-302, BYK-320, BYK-330, BYK-340, BYK-377, BYK-UV3500, manufactured by Shin-Etsu Chemical Co., Ltd. Examples thereof include KF-945, KF-352A, X-22-4272, EFKA-3030, EFKA-3232, EFKA-3035, EFKA-3580, EFKA-3388, and EFKA-3522 from EFKA.

Other additives Various additives applicable to the ultraviolet blocking layer 14 according to the present invention are listed below. For example, JP-A-57-74192, JP-A-57-87989, JP-A-60-72785, JP-A-61-146591, JP-A-1-95091, and JP-A-3-95091. Anti-fading agents, various anionic, cationic or nonionic surfactants described in JP-A-13376, etc., JP-A-59-42993, JP-A-59-52689, JP-A-62-280069 , Optical brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. described in JP-A-61-228771 and JP-A-4-219266 PH adjusters, antifoaming agents, lubricants, antiseptics, antifungal agents, antistatic agents, matting agents, heat stabilizers, antioxidants, flame retardants, crystal nucleating agents, viscosity reducing agents, lubricants, etc. each Such as additives and the like.

[Ultraviolet reflective laminate 11]
The solar reflective film 10, 10 ′ of the present embodiment essentially has the ultraviolet reflective laminated portion 11 disposed on the light incident surface side with respect to the silver reflective layer 13. Further, the ultraviolet reflecting laminated portion 11 is formed between the silver reflecting layer 13 and the ultraviolet blocking layer 14.

  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) contained in sunlight, and preferably 50% or more of the ultraviolet rays of 350 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.

  Moreover, the ultraviolet light reflection laminated portion 11 provided on the light incident surface side is particularly visible light to infrared light so that sunlight (especially 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 with 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 reflection laminated portion 11 has a form of an alternate 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.

(Resin 11b (111b or 112b))
The solar reflective film 10, 10 ′ of the present embodiment is formed of at least one of water and a solvent in which 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 compatible with water. It is preferable that soluble resin (water-soluble resin) 11b (111b or 112b) is included. By including such a specific resin, the ultraviolet reflection laminated portion 11 can be produced in a large area and can be produced in a short time. The definition of “resin soluble in at least one of water and a solvent compatible with water” is as described above.

  The water-soluble resin 11b may be included in only one of the low refractive index layer 111 and the high refractive index layer 112, or may be included in both. As long as at least one of the low refractive index layer 111 and the high refractive index layer 112 contains a resin soluble in at least one of water and 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 small amount of a resin insoluble in both water and a solvent compatible with water.

  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 silicone resins, acrylic resins, olefin resins, vinyl chloride resins, acrylic / urethane resins, and fluorine-containing polymers. Among these, it is preferable to use a water-soluble resin as will be described later. Among resins other than the water-soluble resin, a silicone resin having a siloxane bond, or at least 2 is particularly preferable as a material having excellent weather resistance. An acrylic resin (not included in the water-soluble resin) that is an acrylic copolymer obtained by copolymerizing at least one kind of acrylic monomer is preferably used.

  In the solar reflective films 10 and 10 ′ of the present embodiment, the ultraviolet reflection laminated portion 11 (respective refractive index layers 111 and 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. Although there is no restriction | limiting in particular in the weight average molecular weight of water-soluble resin, 1000-200000 are preferable and 3000-40000 are more preferable from a viewpoint which adjusts and manufactures the viscosity which can be coated.

  As the water-soluble resin, the same resins as those mentioned in the above-mentioned form (I) of the ultraviolet blocking layer 14 can be used, and in particular, from the viewpoint of handling at the time of production and flexibility of the film. , Polyvinyl alcohols, and copolymers containing the same, gelatin, and thickening polysaccharides (particularly celluloses) are preferable, and polyvinyl alcohols are more preferable from the viewpoint of optical properties. These water-soluble resins may be used alone or in combination of two or more.

  As 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 of the polyvinyl alcohol content multiplied by the saponification degree of each polyvinyl alcohol constituting the alcohol is divided by the sum of the polyvinyl alcohol contents. Specifically, the average saponification degree 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 average saponification degree of polyvinyl alcohol having the highest value is represented by 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 respectively calculated. 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 (registered trademark) = PVA) and brands (103 to 245). The number at the beginning of the brand represents the classification of the degree of saponification, and the next two numbers multiplied by 100 are the indication of the degree of polymerization. Number 1 at the beginning of the brand 1 = degree of saponification 98-99 mol%, average value 98.5 mol%, 2 = saponification degree 87-89 mol%, average value 88 mol%, and the following two numbers represent, 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 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 large 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 the 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 more preferable, and the reflectance at 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.

  Furthermore, 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.

  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.

  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.

  1-600 mg is preferable per 1 g of polyvinyl alcohol-type resin, and, as for the total usage-amount of the said hardening | curing agent, 100-500 mg is more preferable.

  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. It is preferable that it is 50-100 mass% with respect to the total amount of, and it is preferable that it is 80-100 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 5 to the total solid content in each refractive index layer when each refractive index layer contains an inorganic oxide (111a to 112a). It is preferable that it is 70 mass%, and it is preferable that it is 8-50 mass%. Even when the inorganic oxide (111a to 112a) is contained, the layer can be formed if the resin content is 3% by mass or more.

(Inorganic oxide 11a (111a or 112a))
At least one layer of the ultraviolet reflecting portion 11 in the solar reflective films 10 and 10 ′ of this embodiment includes at least one inorganic oxide. 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. Further, by reflecting the ultraviolet rays, it is possible to further prevent deterioration of the material disposed in the lower layer and enhance durability. 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. In addition, the said primary average particle diameter is a value measured using the method similar to the measuring method of the primary average particle diameter of the inorganic oxide particle which can be contained in the said ultraviolet shielding layer. 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)
When the high refractive index layer 112 includes the inorganic oxide 112a, the low refractive index layer 111 may not include the inorganic oxide 111a, but the low refractive index layer 111 also includes the inorganic oxide 111a. It is preferable. At this time, it is preferable to use silica (silicon dioxide) 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. From the viewpoint of low refractive index, small particle size, high transparency, and easy handling without forming secondary particles, colloidal silica dispersed in an organic solvent is used. It is particularly preferable to use it. 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 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.

  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 preferably, it is more preferably 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 (tetragonal) titanium oxide particles are preferable.

  The primary average particle diameter of the inorganic oxide particles 112a used for 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 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.

  Furthermore, 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, and 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 JP-A-246351.

  As content of the inorganic oxide particle 112a in the high refractive index layer 112, it is preferable that it is 15-90 mass% with respect to 100 mass% of solid content of the high refractive index layer 112, and is 20-85 mass%. It is more preferable, and it is further more preferable from a viewpoint of a reflectance improvement that it is 30-85 mass%.

(Other additives)
Each refractive index layer (111, 112) preferably contains another additive such as a surfactant from the viewpoint of applicability when formed by coating. As the surfactant used for adjusting the surface tension at the time of coating, known anionic surfactants, nonionic surfactants, amphoteric surfactants and the like can be used, and 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.

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

  Each refractive index layer (111, 112) preferably contains a known 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. 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.

  Each refractive index layer may contain other additives besides the above. As the other additives, those similar to the “other additives” mentioned in the above-mentioned form (I) of the ultraviolet blocking layer 14 can be used, and light stabilizers such as hindered amines are known. These various additives can be used.

(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. In consideration of light scattering and reflection intensity, the range of the total number of low refractive index layers 111 and high refractive index layers 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 the layers, the larger the 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.

  Moreover, 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 expressions (1) and (2).

| DH−dL | <40 nm Formula (1)
| DH + dL | <150 nm Formula (2)
By satisfying the above formulas (1) and (2), the reflectance in the ultraviolet region can be increased. | DH−dL | is more preferably 25 nm or less. The lower limit of | dH−dL | is not particularly limited, but is preferably 5 nm or more in order to ensure an optical path difference. Further, | dH + dL | is more preferably 130 nm or less. The lower limit of | dH + dL | is usually 100 nm or more.

  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 111 (thickness after drying) is preferably 40 to 100 nm, more preferably 50 to 90 nm, and more preferably 60 to 80 nm.

(Manufacturing method of the ultraviolet reflection laminated part 11)
Although there is no restriction | limiting in particular in the manufacturing method of the ultraviolet reflective lamination | stacking part 11 in the solar reflective film 10, 10 'of this form, Since it is large area and mass production is possible, and suitably contains water-soluble resin, A film forming method by coating is preferred. 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. Moreover, it is preferable that the density | concentration of the inorganic oxide particle in the coating liquid for low refractive index layers is 1-50 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. Moreover, it is preferable that the density | concentration of the inorganic oxide particle in the coating liquid for high refractive index layers is 1-50 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 at the time of 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 conditions for the coating and drying method are not particularly limited, and for example, a sequential coating method, a simultaneous multilayer coating method, or the like can be used.

[Silver reflective layer 13]
The silver reflective layer 13 in the solar reflective films 10, 10 ′ of this embodiment is a layer mainly composed of silver or silver having a function of reflecting light in the visible light 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 more 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 400 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 a method for forming the silver reflective layer 13 in the present invention, for example, either a wet method or 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 reflective layer 13 is preferably 10 to 200 nm, more preferably 30 to 150 nm, from the viewpoints of solar 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. .

[Resin film-like support 12]
If the above-described ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13 are formed in this order from the light incident surface side, each of these layers ( Alternatively, the resin film-like support 12 may be included between the portions).

  As the resin film-like support 12, various conventionally known resin films can be used. For example, the film described in paragraph “0021” of JP2012-48102A can be used. 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. 1, when the resin film-like support 12 is disposed at a position farther from the light incident surface side than the silver reflecting layer 13 (that is, from the light incident surface side, the ultraviolet blocking layer 14 and the ultraviolet reflecting laminated portion 11 are arranged. In the case where the silver reflection layer 13 and the resin film support 12 are laminated in this order), the ultraviolet rays hardly reach the resin film support 12. In particular, since the ultraviolet ray can be absorbed and reflected by the ultraviolet blocking layer 14 and the ultraviolet reflecting portion 11 on the light incident surface side of the resin film-like support 12, the ultraviolet rays reach the resin film-like support 12 more. It becomes difficult. Therefore, the resin film-like support 12 can be used even if it is a resin that easily deteriorates with respect to ultraviolet rays. That is, the resin film-like support 12 is not limited by resistance to ultraviolet rays, and various conventionally known resin films can be used. From such a viewpoint, a polyester film such as polyethylene terephthalate can be used as the resin film-like support 12.

  On the other hand, when the silver reflective layer 13 is provided on the side opposite to the light incident surface side of the resin film-shaped support 12 (that is, from the light incident surface side, the ultraviolet blocking layer 14, the ultraviolet reflective laminated portion 11, the resin film-shaped support body. 12 and when the silver reflective layer 13 is laminated in this order), it is preferable to use a resin film in which the resin film-like support 12 can transmit sunlight (particularly visible light to light in the infrared region). desirable. From this 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. Preferably it is 20-200 micrometers.

[Other layers]
If the above-described ultraviolet blocking layer 14, the ultraviolet reflecting laminated portion 11, and the silver reflecting layer 13 are formed in this order from the light incident surface side, each of these layers ( Or other portions) or may be included above and below. In the solar reflective film 10, 10 ′ of the present embodiment, other layers that can be included will be described in detail, but the following layers are examples and are not limited to these.

(Hard coat layer 17)
The solar reflective films 10 and 10 ′ of this embodiment are provided with a hard coat layer (HC layer; scratch-resistant 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 may be further included. That is, the aspect of FIG. 2 may be sufficient.

  Hereinafter, the configuration of the hard coat layer 17 provided on the light incident surface side of the ultraviolet blocking layer 14 will be described.

  Examples of the curable resin used in the hard coat layer 17 include a thermosetting resin and an active energy ray curable resin, and a thermosetting resin is preferable from the viewpoint of suppressing deterioration of the ultraviolet reflection laminated portion. 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.

  Examples of the thermosetting resin include inorganic materials typified by polysiloxane.

  The polysiloxane hard coat (HC layer 17) may be the same as the transparent resin used together with the inorganic oxide in the form (II) of the ultraviolet blocking layer. Of these, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane and the like are preferably 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 hard coat layer 17 will break due to stress, and if it is too thin, it is difficult to maintain the hardness. Therefore, 1-5 micrometers is preferable as thickness, and it is preferable that it is 1.5-3 micrometers.

  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) or the like can be used.

  The thickness of the hard coat 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 curl of the hard coat layer is large and the bending resistance tends to be lowered.

  The hard coat layer 17 can be prepared by applying a cured resin layer forming composition (coating solution) by wire bar coating, spin coating, or dip coating, and also by a dry film forming method such as vapor deposition. Can do. 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, heat treatment for 30 minutes to several days is required at a temperature of 50 ° C. or more and 150 ° C. or less in order to promote curing / 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 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, n-propanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl). Isobutyl ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents can be appropriately selected or used by mixing them.

  When adhesion to the lower layer of the hard coat layer 17 is not obtained, a primer layer (not shown in FIGS. 1 and 2) can be formed before laminating the cured resin layer. Although the film thickness of a primer layer is not specifically limited, It is about 0.1-10 micrometers. Preferable examples of the resin constituting the primer layer include polyvinyl acetal resin and acrylic resin.

(Adhesive layer 15)
The solar reflective film 10, 10 ′ of this embodiment may have 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. . It does not restrict | limit especially as an adhesive which comprises the adhesion layer 15, For example, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl butyral adhesive, an ethylene-vinyl acetate adhesive etc. are illustrated. be able to.

  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, those described in paragraph “0077” of JP 2012-53382 A as a main monomer serving as a skeleton. In addition, methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, glycidyl methacrylate are used as functional group-containing monomers to promote crosslinking, provide stable adhesive strength, and maintain a certain level of adhesive strength even in the presence of water. Etc. 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.

  In this adhesive layer 15, as additives, for example, stabilizers, surfactants, ultraviolet absorbers, flame retardants, antistatic agents, antioxidants, thermal stabilizers, lubricants, fillers, colorants, adhesion modifiers, etc. Can also be included.

  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 local shrinkage and expansion of the adhesive layer, and therefore 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 surface 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 16 may be any material that can impart protection of the adhesive layer 15, 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 Sheet, plastic film or sheet such as fluorine film, resin film or sheet kneaded with titanium oxide, silica, aluminum powder, copper powder, resin film or sheet coated with resin kneaded with these, aluminum, etc. A resin film, a sheet, or the like that has been subjected to surface processing using metal deposition or the like 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.

(Corrosion prevention layer)
Prevents moisture and chemicals in the air from entering the silver reflective layer 13 (mirror surface) (and thus prevents corrosion of silver and silver-containing alloy materials (especially silver) in the silver reflective layer 13), and from the outside For the purpose of protecting against mechanical pressure, such as impact and scratching, a corrosion prevention layer may be provided. That is, the corrosion prevention layer 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 is desirably provided adjacent to the silver reflection 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 may consist of only one layer or may consist of a plurality of layers.

  The thickness of the corrosion prevention layer (in the case of two or more layers, the total thickness) is preferably 1 to 10 μm, more preferably 2 to 8 μm. If the thickness of the corrosion prevention layer is 1 μm or more, it may be caused by intrusion of moisture or chemicals in the air into the silver reflecting layer 13 (mirror surface), and mechanical pressure from the outside, for example, impact or scratching. Can be protected. If the thickness of the corrosion prevention layer is 10 μm or less, the flexibility can be sufficiently maintained, and cracks and cracks can be effectively prevented.

(Anchor coat layer)
In the solar reflective film 10, 10 ′ of this embodiment, an anchor coat layer (not shown in FIGS. 1 and 2) may be provided. The anchor coat 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 coat 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 like. Therefore, smoothness and transparency (sunlight transmittance) are required to bring out the high reflection performance inherent in 13.

  The resin used for the anchor coat layer is not particularly limited as long as it satisfies the above conditions of adhesion, heat resistance, transparency and smoothness, and polyester resin, acrylic resin, melamine resin, epoxy resin Resin, polyamide resin, vinyl chloride resin, vinyl chloride vinyl acetate copolymer resin, etc. can be used singly or as a mixed resin. From the viewpoint of weather resistance, polyester resin and melamine resin mixed resin or polyester resin A mixed resin of acrylic resin and 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 coat layer is preferably 0.01 to 3 μm, more preferably 0.1 to 2 μm. By satisfying this range, it is possible to cover the unevenness on the surface of the resin film-like support 11 while maintaining adhesion, to improve smoothness, and to sufficiently cure the anchor coat layer. It becomes possible to raise the reflectance of the solar reflective film 10 of a form.

  Moreover, it is preferable that an anchor coat layer contains the same corrosion inhibitor as the corrosion inhibitor contained in the above-mentioned corrosion prevention layer.

(Gas barrier layer)
A gas barrier layer (not shown in FIGS. 1 and 2) may be provided on the light incident surface side of the silver reflecting layer 13. It is preferable to provide a gas barrier layer between the hard coat 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. 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.

  In addition, the solar reflective film 10, 10 ′ of this embodiment has an easy-adhesion layer (adhesive layer), a conductive layer, an antistatic layer, an antifouling layer, a deodorizing layer, a flow according to the environment and application used. You may have 1 or more of functional layers, such as a droplet layer, a slippery layer, an abrasion-resistant layer, an antireflection layer, an electromagnetic wave shield layer, a printing layer, a fluorescence light emitting layer, and a hologram layer.

<Sunlight reflector>
The second aspect of the present invention provides a solar reflector 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-based 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.

<Sunlight reflector>
The third aspect of the present invention provides 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 a 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.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to 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. Unless otherwise specified, measurements of operation and physical properties were performed under conditions of room temperature (20 ° C.) / Relative humidity 40 to 50%.

[Preparation of coating solution]
(Preparation of coating liquid L1 for low refractive index layer)
While heating and stirring 10 parts by mass 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 by the coating liquid L1 for low refractive index layer was 1.50. In addition, the measuring method of a refractive index is as follows.

(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)
To 45 parts by mass of silica-attached titanium dioxide sol (solid content 20.0% by mass) obtained as described above as inorganic oxide fine particles 112a, polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, (Made by Kuraray Co., Ltd.), 2 parts by weight of 5% by weight aqueous solution, 10 parts by weight of 3% by weight aqueous boric acid solution, and 10 parts by weight of 2% by weight aqueous citric acid solution were added. 20 parts by weight of a 5% by weight aqueous solution of alcohol (PVA-117, degree of polymerization 1700, saponification degree 98.5 mol%, manufactured by Kuraray Co., Ltd.), 1% by weight aqueous solution 1 of a surfactant (Rapisol A30, manufactured by NOF Corporation) Mass parts were added, and 12 parts by mass of pure water were added to prepare a coating solution H1 for a high refractive index layer.

  The refractive index of the high refractive index layer obtained by the coating liquid H1 for high refractive index layer was 1.95. In addition, the measuring method of a refractive index is as follows.

(Preparation of coating solution for hard coat layer)
20 parts by mass of water and 2 parts by mass of acetic acid were placed in a synthesis container and sufficiently stirred while maintaining the liquid temperature at 0 to 10 ° C. In this, 50 parts by mass of methyltrimethoxysilane (chemical formula: CH ₃ Si (OCH ₃ ) ₃ , manufactured by Kanto Chemical Co., Ltd.), fluorine-bonded group and methoxy group-containing FAS (KBM-7803, manufactured by Shin-Etsu Chemical Co., Ltd.) 0 0.5 parts by mass was rapidly added, 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 parts by mass of a silicone-based surface conditioner (BYK-300 (organically modified polysiloxane), manufactured by Big Chemie Japan Co., Ltd.), 0.05 parts by mass of sodium acetate, and n -The coating liquid for hard-coat layers was obtained by containing 15 mass parts of propanol.

[Production of solar reflective film]
(Preparation of silver deposited film)
As the resin film-like support 12, a biaxially stretched polyester film (a polyethylene terephthalate film having a thickness of 50 μm (A4300: a film having a double-sided easy-adhesive layer, manufactured by Toyobo Co., Ltd.)) was used.

  Polyester resin (Polyester SP-181, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Melamine resin (Super Becamine J-820, manufactured by DIC Corporation), TDI isocyanate (2,4-tolylene diisocyanate), HDMI isocyanate (1,6-hexamethylene diisocyanate) in a resin solid content ratio of 20: 1: 1: 2 (mass ratio), a resin mixed in toluene so as to have a solid content concentration of 10% by mass, In addition, an anchor coat layer having a thickness of 0.1 μm was formed by coating by a gravure coat method.

  Next, on the anchor coat layer, silver was vacuum-deposited at a deposition speed of 100 m / sec as a silver reflective layer 13 by a vacuum deposition method to form a silver reflective layer 13 having a thickness of 80 nm.

Example 1 (Preparation of solar reflective film 10A)
An acrylic adhesive (Nissetsu SZ-7103, manufactured by Nippon Carbide Industries Co., Ltd.) was applied to the release film 16 (Acryprene HBS010P, thickness 100 μm, manufactured by Mitsubishi Rayon Co., Ltd.) so as to have a film thickness of 25 μm after drying. . The release film 16 was laminated on the surface of the silver deposited film 10a opposite to the surface on which the silver reflective layer 13 was deposited to form an adhesive layer 15.

  Next, a high refractive index layer 112 and a low refractive index layer 111 were formed on the silver reflective layer 13 formed on the resin film-like support 12 by a simultaneous multilayer coating method. Specifically, a high refractive index layer coating liquid H1 is used as the high refractive index layer 112, a low refractive index layer coating liquid L1 is used as the low refractive index layer 111, and a slide hopper coating apparatus capable of coating 21 layers in layers is used. Thus, each layer was formed. At this time, the coating liquid L1 for the low refractive index layer and the coating liquid H1 for the high refractive index layer were coated on the resin film-like support 12 heated to 45 ° C. while keeping the temperature at 45 ° C. Note that simultaneous multilayer coating was performed so that H1 was in contact with the silver reflective layer 13, L1 was formed on H1, and H1 and L1 were alternately laminated. 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). Formed. The film thickness after drying was 64 nm for each low refractive index layer 111 coated with the coating liquid L1 for low refractive index layer, and 47 nm for each high refractive index layer 112 coated with the coating liquid H1 for high refractive index.

  On the ultraviolet reflecting laminated portion 11 formed as described above, an ultraviolet blocking layer 14 was produced as follows. That is, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine (in the above general formula (1), k, m, p, l, n, q) = 0) and polymethylmethacrylate (BR-85, manufactured by Mitsubishi Rayon Co., Ltd.) were prepared so as to be dissolved at 20% by mass. At this time, the coating solution was prepared so that the triazine, which is an ultraviolet absorber, was 5 mass% with respect to the total mass of the ultraviolet blocking layer 14. The coating solution was applied by a micro gravure coater and then dried by blowing hot air at 85 ° C. for 1 minute. In addition, it apply | coated so that the film thickness after drying might be set to 3 micrometers at this time.

  Subsequently, a hard coat layer 17 was prepared as follows.

  The hard coat layer coating solution prepared as described above was applied to the surface of the ultraviolet blocking layer 14 formed as described above so as to have a dry film thickness of 3 μm, and dried at 90 ° C. for 1 minute. Thereafter, the hard coat layer 17 was formed in a constant temperature environment of 45 ° C. for 7 days.

  A solar reflective film (Sample 1) was obtained as described above.

Example 2
In Example 1, the solar reflective film (Sample 2) was changed in the same manner as in Example 1 except that the method of forming the ultraviolet blocking layer 14 was changed as follows and the hard coat layer 17 was not formed. Got.

  The ultraviolet blocking layer 14 was produced as follows. That is, 8 parts by mass of titanium dioxide (average particle size 8 nm) and 30 parts by mass of a polyorganosiloxane resin were dispersed in methanol to prepare a coating solution for an ultraviolet blocking layer. At this time, the coating liquid was prepared so that the titanium oxide which is an ultraviolet absorber might be 5 mass% with respect to the total mass of the ultraviolet blocking layer 14. The said coating liquid was apply | coated with the gravure coater on the ultraviolet reflective lamination part 11 produced like Example 1. FIG. At this time, coating was performed so that the film thickness after drying was 3 μm. This was dried by blowing warm air of 90 ° C. for 1 minute. Thereafter, the ultraviolet blocking layer 14 was formed in a constant temperature environment of 45 ° C. for 7 days.

Example 3
In Example 1, a solar reflective film (Sample 3) was obtained in the same manner as Example 1 except that the hard coat layer 17 was not formed.

Example 4
In Example 1 above, the solar light reflective film was formed in the same manner as in Example 1 except that the formation of the ultraviolet blocking layer 14 was repeated twice in succession (sequential application) and the hard coat layer 17 was not formed. (Sample 4) was obtained. In other words, in this example, two ultraviolet blocking layers 14 composed of the ultraviolet blocking layer (1) and the ultraviolet blocking layer (2) were formed.

Example 5
In Example 1, after producing the ultraviolet blocking layer (1) containing 2,4,6-tris (4-biphenylyl) -1,3,5-triazine, the ultraviolet blocking layer containing titanium dioxide on the layer. A solar reflective film (Sample 5) was obtained in the same manner as in Example 1 except that (2) was formed and a hard coat layer was not formed. The ultraviolet blocking layer (2) was formed in the same manner as in Example 2, and the ultraviolet blocking layer (2) having a thickness of 3 μm was formed.

Example 6
In Example 2 above, the solar reflective film (Sample 6) was prepared in the same manner as in Example 2 except that the titanium dioxide contained in the ultraviolet blocking layer 14 was changed to 5 parts by mass of zirconium dioxide (average particle size 10 nm). Obtained.

Example 7
In Example 2, the solar reflective film (Sample 7) was prepared in the same manner as in Example 2 except that the titanium oxide contained in the ultraviolet blocking layer 14 was changed to 5 parts by mass of tungsten oxide (average particle size 10 nm). Obtained.

Comparative Example 1
In Example 1 above, a solar reflective film (Sample 8) was obtained in the same manner as Example 1 except that the ultraviolet blocking layer 14 was not formed.

Comparative Example 2
In Example 3 above, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine, which is an ultraviolet absorber, was changed to Tinuvin 234 (benzotriazole ultraviolet absorber, manufactured by Ciba Japan Co., Ltd.). Except having done, it carried out similarly to Example 3, and obtained the sunlight reflective film (sample 9).

Comparative Example 3
In the above Example 1, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine, which is an ultraviolet absorber, was changed to Tinuvin 234 (benzotriazole ultraviolet absorber, manufactured by Ciba Japan Co., Ltd.). Except having done, it carried out similarly to Example 1, and obtained the sunlight reflective film (sample 10).

Comparative Example 4
In Example 3 above, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine, which is an ultraviolet absorber, was tinuvin 1577 (compound represented by the following chemical formula A, manufactured by Ciba Japan Co., Ltd.) A solar reflective film (sample 11) was obtained in the same manner as in Example 3 except that the change was made.

Comparative Example 5
In Example 1 above, 2,4,6-tris (4-biphenylyl) -1,3,5-triazine, which is an ultraviolet absorber, was tinuvin 1577 (a compound represented by the above chemical formula A, manufactured by Ciba Japan Co., Ltd.). A solar reflective film (sample 12) was obtained in the same manner as in Example 1 except that the change was made.

Comparative Example 6
In Example 4 above, the ultraviolet absorber contained in the ultraviolet blocking layer (1) was changed to Tinuvin 1577 (compound represented by the above chemical formula A, manufactured by Ciba Japan Co., Ltd.) and included in the ultraviolet blocking layer (2). A solar reflective film (sample 13) was obtained in the same manner as in Example 4 except that the ultraviolet absorber to be used was changed to Tinuvin 234 (benzotriazole ultraviolet absorber, manufactured by Ciba Japan Co., Ltd.).

[Evaluation of solar reflective film]
The following performance evaluation was performed about each solar reflective film (samples 1-13) produced above.

(Measurement of single film refractive index of each layer)
The refractive indexes of the high refractive index layer and the low refractive index layer constituting the ultraviolet reflective laminate were measured by the following method.

  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 a spectrophotometer U-4100 (solid sample measurement system) manufactured by Hitachi, Ltd., the surface opposite to the measurement surface (back surface) of each sample is roughened, and then light absorption treatment 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.

(Measurement of light transmittance)
The light transmittance was measured as follows. First, a single film consisting only of an ultraviolet blocking layer (all layers when the ultraviolet blocking layer consists of a plurality of layers) was prepared on a glass substrate to obtain a sample (single film sample). With respect to the sample, the light transmittance was measured using a spectrophotometer (device name: Hitachi, manufactured by U-4100) at measurement wavelengths of 350 nm and 370 nm. At this time, the same base material (glass substrate) as the sample (produced single film sample) was used as the baseline.

(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 (regular reflectance when the incident angle is 5 degrees) were measured. The spectrophotometer U-4100 (solid sample measurement system) manufactured by Hitachi, Ltd. was used for the measurement. The wavelength range of the reflectance was measured at 350 to 2500 nm. The average reflectance R (wavelength 350-2500 nm) calculated from the measured values in the reflectance wavelength range 350-2500 nm was measured.

(Evaluation of weather resistance: measurement of 5 degree regular reflectance after ultraviolet irradiation)
For each of the solar reflective films produced above, a metal halide lamp type weather resistance tester (manufactured by Daipura Wintes Co., Ltd.) was used. Sample surface radiation intensity: 2.16 MJ / m ² or less, black panel temperature 63 ° C., relative humidity : UV irradiation was performed under the conditions of 50% and irradiation time of 500 hours (weather resistance test). Subsequently, the measurement of the regular reflectance of 5 degrees was measured by the same method as described above, the initial reflectance and the reflectance after ultraviolet irradiation were compared, and the film was evaluated according to the following evaluation.

≪Reduction of maximum reflectance after weather resistance test with respect to initial maximum reflectance (= initial maximum reflectance−maximum reflectance after weather resistance test (%)) ≫
5: Maximum reflectance decrease is less than 1% 4: Maximum reflectance decrease is 1% or more and less than 2% 3: Maximum reflectance decrease is 2% or more and less than 3% 2: Maximum reflectance decrease is 3% or more and less than 5% 1 : Maximum reduction in reflectance is 5% or more.

(Evaluation of weather resistance: Evaluation of adhesion)
For each of the solar reflective films produced above, a metal halide lamp type weather resistance tester (manufactured by Daipura Wintes Co., Ltd.) was used. Sample surface radiation intensity: 2.16 MJ / m ² or less, black panel temperature 63 ° C., relative humidity : UV irradiation was performed under the conditions of 50% and irradiation time of 500 hours. The film was then stored for 200 hours under the conditions of 60 ° C. and 90% RH.

  About the said film, the cross-cut test based on JISK5600-5-6: 1999 was done. 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 on this, peeled off quickly at an angle of 90 degrees, the number of grids remaining without peeling was measured, and the adhesion between the ultraviolet reflective laminate and the silver reflective layer was evaluated according to the following criteria: .

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.

  The results of the evaluation are shown in Table 1 below. In addition, regarding the “configuration of the ultraviolet blocking layer”, the “ultraviolet blocking layer (2)” is provided on the ultraviolet blocking layer (1) on the basis of the resin film support (base material), It refers to the layer formed on the light incident surface side. In addition, when the UV blocking layer (1) and the UV blocking layer (2) are not separated, a single UV blocking layer is formed.

  As is clear from the results in Table 1, the solar reflective film according to the present invention maintains a reflectance of 90% or more even after the durability test, and thus has a high reflectance and is durable. It became clear that it was excellent in property. Further, the comparison between Samples 2, 6 and 7 showed that particularly good results were obtained when the inorganic oxide contained in the ultraviolet blocking layer was titanium oxide. Further, the comparison between Samples 1 to 7 shows that the above tendency becomes remarkable when the ultraviolet blocking layer is composed of two or more layers as in Sample 5 and an ultraviolet blocking layer containing titanium oxide is provided. It was done.

  On the other hand, it was shown that it was difficult to obtain sufficient durability when Tinuvin 234 and Tinuvin 1577, which are general ultraviolet absorbers, were used as in Samples 9 to 13.

10, 10 'solar reflective film,
11 UV reflective laminate,
11a Inorganic oxide (particles) in the ultraviolet reflective laminate,
11b resin,
12 resin film-like support,
13 Silver reflection layer,
14 UV blocking layer,
15 adhesive layer,
16 Release material (release film),
17 Hard coat 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.

Claims (6)

In order from the light incident side, it has an ultraviolet blocking layer that blocks a part of ultraviolet rays, an ultraviolet reflecting laminated portion containing at least one inorganic oxide, and a silver reflecting layer,
The ultraviolet blocking layer is a solar reflective film having a light transmittance of 10% or less at a wavelength of 350 nm and a light transmittance of 50% or more at a wavelength of 370 nm.   The solar reflective film according to claim 1, wherein the ultraviolet blocking layer contains 2,4,6-tris (4-biphenylyl) -1,3,5-triazine or a derivative thereof.   The solar reflective film according to claim 1 or 2, wherein the ultraviolet blocking layer contains at least one of titanium oxide, zirconium oxide, and tungsten oxide. 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 any one of claims 1 to 3, wherein a saponification degree of the polyvinyl alcohol (A) is different from a saponification degree of the polyvinyl alcohol (B).   The sunlight reflector which has a sunlight reflective film of any one of Claims 1-4.   A solar light reflection device comprising the solar light reflector according to claim 5.