WO2017043288A1

WO2017043288A1 - Optical reflection film

Info

Publication number: WO2017043288A1
Application number: PCT/JP2016/074211
Authority: WO
Inventors: 翔太畠沢; 一仁伊原
Original assignee: コニカミノルタ株式会社
Priority date: 2015-09-09
Filing date: 2016-08-19
Publication date: 2017-03-16

Abstract

Provided is an optical reflection film which is provided with: a base; a reflective layer that is provided on the base; and a first ultraviolet absorbing layer that is provided on the reflective layer. This optical reflection film is configured such that an ultraviolet absorbent is contained in the base and/or in a layer that is provided on a surface of the base, said surface being on the reverse side of the surface on which the reflective layer is formed, so that deterioration of the base is suppressed.

Description

Optical reflective film

The present invention relates to an optical reflective film having an infrared reflective laminate formed by alternately laminating layers having different refractive indexes.

In recent years, interest in energy-saving measures has increased, and heat insulation glass with infrared shielding properties for the purpose of shielding solar radiant energy entering indoors or in vehicles and reducing temperature rise and cooling load in architectural glass and vehicle glass. Is adopted. In addition, a method of attaching an optical reflection film formed by laminating layers having different refractive indexes to glass and blocking the transmission of heat rays in sunlight has attracted attention as a simpler method.

In general, an optical reflective film is attached to a window glass or the like via an adhesive layer, and a method of protecting the reflective layer from the external environment by placing the reflective layer between the adhesive layer and the substrate is used. Yes.
As an optical reflection film that reflects infrared rays, a structure having an infrared reflection laminate (reflection layer) in which layers having different refractive indexes are alternately laminated on a base material has been proposed (for example, a patent). Reference 1). This infrared reflective laminate is composed of a high refractive index layer in which metal oxide fine particles such as titanium oxide are dispersed in a water-soluble resin, and a low refractive index layer in which particles of silicon dioxide and the like are dispersed. . In addition, in the optical reflection film, a method is used in which an ultraviolet absorber is introduced into the adhesive layer to block ultraviolet rays incident from the window surface side and prevent deterioration of the base material and the reflective layer.

JP 2012-131130 A

However, there is a problem that the base material breaks due to deterioration when the optical reflective film is peeled off for replacement after long-term use. If the base material is broken, workability at the time of replacement or the like deteriorates.

In order to solve the above-described problems, the present invention provides an optical reflection film in which deterioration of a substrate is suppressed.

The optical reflective film of the present invention includes a base material, a reflective layer provided on the base material, and a first ultraviolet absorbing layer provided on the reflective layer. And an ultraviolet absorber is included in at least any one of a base material and the layer provided on the surface on the opposite side to the surface in which the reflective layer of the base material was formed.

According to the present invention, it is possible to provide an optical reflective film in which deterioration of the substrate is suppressed.

It is a figure which shows the schematic sectional drawing of the optical reflection film of 1st Embodiment. It is a figure which shows the schematic sectional drawing of the optical reflection film of the modification of 1st Embodiment. It is a figure which shows schematic sectional drawing of the optical reflection film of 2nd Embodiment. It is a figure which shows schematic sectional drawing of the optical reflection film of the modification of 2nd Embodiment.

Hereinafter, although the example of the form for implementing this invention is demonstrated, this invention is not limited to the following examples.
The description will be given in the following order.
1. Embodiment of optical reflection film (first embodiment)
2. Embodiment of optical reflection film (second embodiment)

<1. Embodiment of Optical Reflective Film (First Embodiment)>
Hereinafter, specific embodiments of the optical reflective film of the present invention will be described.
The optical reflective film includes a base material, a reflective layer, and a first ultraviolet absorbing layer. The reflective layer is provided in a form sandwiched between the base material and the first ultraviolet absorbing layer. And an optical reflection film is provided with the layer (2nd ultraviolet absorption layer) containing an ultraviolet absorber on the opposite side to a 1st ultraviolet absorption layer with respect to a reflection layer.

Examples of such a second ultraviolet absorbing layer include a configuration in which the base material itself contains an ultraviolet absorber, so that the base material becomes the second ultraviolet absorbing layer. Moreover, the structure which comprises the layer which contains a ultraviolet absorber on the outer side (opposite side of a reflection layer) of a base material, and makes this layer a 2nd ultraviolet absorption layer is mentioned. As a layer provided in the outer side of a base material, the hard-coat layer provided in order to protect the surface of a base material, the anchor coat layer provided between a base material and a hard-coat layer, etc. are mentioned, for example. Moreover, as a layer provided in the outer side of a base material, layers other than a hard-coat layer and an anchor-coat layer may be sufficient, and if it is the structure which can hold | maintain an ultraviolet absorber, it will not specifically limit.

Further, the optical reflective film preferably has an average spectral reflectance at a wavelength of 1000 to 1200 nm of 30% or more and less than 90%, and a maximum spectral transmittance at a wavelength of 300 to 380 nm of 50% or less. The reflectance, transmittance, and refractive index of the optical reflection film and each component can be determined according to the following method. First, an optical reflection film to be measured or a sample formed of a single layer of each layer is prepared using a substrate such as glass or a resin film as necessary, and the prepared sample is cut into 10 cm × 10 cm. And the back side of the measurement side of each sample is roughened, and light absorption processing is performed with a black spray to prevent reflection of light on the back side. Thereafter, using a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4100), the average value obtained by measuring the reflectance in the visible light region (wavelength 400 nm to 700 nm) at 25 points under the condition of regular reflection at 5 degrees. From this, the average refractive index is obtained. Further, the reflectance (for example, wavelength 1000 to 1200 nm, wavelength 380 to 750 nm) of the optical reflection film at each wavelength is measured, and the average reflectance and transmittance are calculated.

Examples of the ultraviolet absorber contained in the second ultraviolet absorbing layer include benzotriazole compounds, triazine compounds, and benzophenone compounds. It is preferable that a 2nd ultraviolet absorption layer contains at least 1 or more types chosen from said ultraviolet absorber. Moreover, it is preferable that a 1st ultraviolet absorption layer also contains at least 1 type or more chosen from said ultraviolet absorber.

The reflective layer preferably contains a polymer compound having a glass transition temperature of 0 ° C. or less in a layer (high refractive index layer or low refractive index layer) provided on the most base side (lowermost layer). Furthermore, the polymer compound having a glass transition temperature of 0 ° C. or lower preferably has a urethane bond.

[Configuration of optical reflection film]
FIG. 1 shows a schematic configuration of the optical reflection film. The optical reflective film 10 shown in FIG. 1 includes a base material 11, a reflective layer 12, and a first ultraviolet absorption layer 13. The optical reflection film 10 has a first ultraviolet absorption layer 13 side bonded to a window glass or the like, and the first ultraviolet absorption layer 13 side is directed to the optical reflection film 10 mainly for reflection on the reflection layer. The light including the wavelength is incident. In the following description, the surface on the first ultraviolet absorption layer 13 side of the optical reflection film 10 is referred to as “front surface”, and the surface on the base material 11 side of the optical reflection film 10 is referred to as “back surface”.

In the optical reflective film 10, the reflective layer 12 has a configuration in which high refractive index layers and low refractive index layers are alternately laminated. The first ultraviolet absorbing layer 13 is provided on the main surface opposite to the base material 11 with respect to the reflective layer 12 provided on the base material 11. And in the optical reflection film 10, the base material 11 itself is comprised as a 2nd ultraviolet absorption layer because the base material 11 contains an ultraviolet absorber.

Therefore, the optical reflective film 10 has a configuration in which the reflective layer 12 is sandwiched between the first ultraviolet absorbing layer 13 and the substrate 11 which is the second ultraviolet absorbing layer. In this way, the reflective layer 12 is sandwiched between the first ultraviolet absorbing layer 13 and the second ultraviolet absorbing layer (base material 11), so that the ultraviolet rays from the surface side of the optical reflecting film 10 are changed to It can be absorbed by the ultraviolet absorbing layer 13. Furthermore, the ultraviolet rays from the back surface side of the optical reflection film 10 can be absorbed by the base material 11 which is the second ultraviolet absorption layer. For this reason, the ultraviolet irradiation to the reflective layer 12 is suppressed, and the influence of the deterioration of the optical characteristics of the optical reflective film 10 caused by the deterioration of the reflective layer 12 due to the ultraviolet light is suppressed.

Furthermore, the ultraviolet rays applied to the substrate 11 can be suppressed by absorbing the ultraviolet rays from the surface side of the optical reflecting film 10 by the first ultraviolet absorbing layer 13. Furthermore, the ultraviolet absorber from the back surface side of the optical reflection film 10 can be absorbed by the ultraviolet absorber contained in the substrate 11 by including the ultraviolet absorber in the substrate 11 itself. As a result, deterioration (decomposition) of the base material 11 due to ultraviolet rays is suppressed. Therefore, when performing the replacement | exchange operation | work etc. of the optical reflection film 10, the fracture | rupture of the base material 11 can be suppressed and the fall of workability | operativity can be suppressed.

Hereinafter, each configuration of the optical reflection film 10 will be described. In the following description, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, operations and physical properties are measured under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 60%.

[Reflective layer]
The reflective layer 12 of the optical reflective film 10 has an alternate stack of high refractive index layers and low refractive index layers. The reflection layer 12 includes at least one laminate (unit) in which high refractive index layers and low refractive index layers having different refractive indexes are alternately laminated so that intrusion of heat rays (infrared rays) can be prevented. It is.

The “high refractive index layer” and the “low refractive index layer” are obtained by comparing the refractive index difference between two adjacent layers with the higher refractive index layer as the higher refractive index layer and the lower refractive layer as the lower refractive index layer. A low refractive index layer is used. Therefore, the high refractive index layer and the low refractive index layer in the reflective layer 12 are determined by comparing the refractive indexes of two adjacent layers in each layer constituting the reflective layer 12. For this reason, the names of these structures are replaced as needed depending on the structure of the laminate and the refractive index relationship with the layer to be compared. Further, the “high refractive index layer” and the “low refractive index layer” can be applied to all forms except for the case where two adjacent layers have the same refractive index in each layer constituting the film.

The reflection layer 12 includes a polymer that is a main component of the layer. When the reflective layer 12 is mainly composed of a polymer, the flexibility of the layer is improved with respect to the reflective layer of the inorganic film formed only of the metal oxide material. For this reason, a film crack can be prevented effectively. Moreover, the adhesiveness between each layer can be improved.

The reflective layer 12 preferably has at least one laminate (unit) in which a high refractive index layer containing a polymer and a low refractive index layer containing a polymer are laminated. In addition to the polymer, the reflective layer 12 may include other substances such as metal oxides (particles) and other additives.

Furthermore, by forming the reflective layer 12 mainly with a polymer, the reflective layer 12 can be produced using a liquid phase film forming method such as a coating method. For this reason, uniform and large-area film formation can be easily performed. Moreover, since the film-forming speed can be increased by using the liquid phase film-forming method, the manufacturing cost and mass productivity are excellent. Furthermore, by using a coating method or the like, it becomes easy to control the thicknesses of the high refractive index layer and the low refractive index layer to arbitrary thicknesses.

Furthermore, unlike the vapor phase film forming method, the liquid phase film forming method does not require film formation at a high temperature. For this reason, the selection range of a base material spreads. Since the reflective layer containing a polymer is excellent in flexibility as described above, even when the optical reflective film 10 is bent, the occurrence of cracks and peeling at the bent portion can be suppressed by using a flexible resin film. .
Furthermore, it suppresses peeling between layers due to a difference in shrinkage ratio between the reflective layer 12 and other layers due to temperature change, or between the high refractive index layer and the low refractive index layer constituting the reflective layer 12. Can do.

In the reflective layer 12, a mixed layer in which components constituting each layer are mixed may be formed at the interface between the high refractive index layer and the low refractive index layer. When such a mixed layer exists, the high refractive index layer includes a set of portions in which the components constituting the high refractive index layer are 50% by mass or more in the mixed layer, thereby forming the low refractive index layer. A group of sites where the component to be added exceeds 50 mass% is included in the low refractive index layer.

Specifically, when each of the high refractive index layer and the low refractive index layer contains metal oxide particles, the metal oxide particles (first metal oxide particles) contained in the low refractive index layer, and the high refractive index layer The metal oxide particles (second metal oxide particles) contained in the mixture are mixed at the interface between the two layers, and a mixed layer including the first metal oxide particles and the second metal oxide particles is formed. There is a case. In this case, it is regarded as a low refractive index layer or a high refractive index layer depending on the abundance ratio of the first metal oxide particles and the second metal oxide particles. Specifically, the low refractive index layer means that the first metal oxide particles are 50 to 100% by mass with respect to the total mass of the first metal oxide particles and the second metal oxide particles. Means the layers involved. The high refractive index layer means that the second metal oxide particles are more than 50% by mass and less than 100% by mass with respect to the total mass of the first metal oxide particles and the second metal oxide particles. Means the layers involved. The type and amount of metal oxide particles contained in each layer can be analyzed by energy dispersive X-ray spectroscopy (EDX).

The reflective layer 12 may be a laminate in which a high refractive index layer containing a polymer and a low refractive index layer containing a polymer are alternately laminated, and the number (total number) of the high refractive index layer and the low refractive index layer is There is no particular limitation. Preferably, it is in the range of 10 to 50 layers, preferably 13 to 39 layers. If the number of laminated layers is 10 or more, a desired infrared reflectance is obtained, and if it is 13 or more, a higher infrared reflectance is obtained and the heat shielding effect is improved. Further, if the number of laminated layers is 50 or less, the reflective layer 12 is not easily broken and excellent in that sufficient weather resistance can be obtained, for example, the edge peeling can be suppressed. Furthermore, if the number of laminated layers is 39 or less, high weather resistance is obtained, such as preventing the reflective layer 12 from cracking and preventing edge peeling.

The reflective layer 12 has a high refractive index layer, a low refractive index, and the lowermost layer (most layer on the side of the base material 11) and the outermost layer (most layer on the side opposite to the base material 11). Any of the rate layers may be used. When the lowermost layer and the outermost layer of the reflective layer 12 are low refractive index layers, adhesion to the adjacent layer (for example, the base material 11) of the lowermost layer and blowing resistance of the outermost layer are likely to be improved.

The reflective layer 12 can increase the infrared reflectance with a smaller number of layers as the difference in refractive index between the adjacent high refractive index layer and low refractive index layer increases.
In the reflective layer 12, the high refractive index layer preferably has a higher refractive index. The refractive index of the high refractive index layer is preferably 1.70 to 2.50, more preferably 1.80 to 2.20, and even more preferably 1.90 to 2.20.
In the reflective layer 12, the low refractive index layer preferably has a lower refractive index. The refractive index of the low refractive index layer is preferably 1.10 to 1.60, more preferably 1.30 to 1.55, and still more preferably 1.30 to 1.50.

In a laminate composed of a high refractive index layer and a low refractive index layer, it is preferable that at least one pair of refractive index difference between adjacent high refractive index layer and low refractive index layer is 0.1 or more, 0.2 or more More preferably, it is more preferably 0.25 or more. In the case where the reflective layer 12 has a plurality of high refractive index layers and low refractive index layers, it is preferable that the refractive index difference is within the preferred range in all layers. However, the outermost layer and the lowermost layer of the reflective layer 12 may have a configuration outside the above preferred range.

The reflectance of the specific wavelength region in the reflective layer 12 is determined by the refractive index difference between the two adjacent layers (the high refractive index layer and the low refractive index layer) and the number of stacked layers. Rate is obtained. The refractive index difference and the required number of layers can be calculated using commercially available optical design software. For example, in order to obtain an infrared reflectance (infrared shielding ratio) of 90% or more, if the difference in refractive index is smaller than 0.1, lamination exceeding 100 layers is required, and transparency is lowered. For this reason, the refractive index difference between adjacent layers is preferably 0.1 or more. Particularly preferably, it is 0.3 or more, more preferably 0.4 or more. From the viewpoint of improving reflectivity and reducing the number of layers, there is no upper limit to the difference in refractive index between the adjacent high refractive index layer and low refractive index layer, but it is substantially about 1.4.

Further, in the single layer film, 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 expressed by [n · d = λ / 4], the reflection at the specific wavelength λ is reduced. , Can be strengthened by the phase difference. Here, n is the refractive index, d is the physical film thickness of the layer, n · d is the optical film thickness, and λ is the wavelength.

As described above, the reflection layer 12 can control reflection of each wavelength by using the optical path difference. That is, the reflectance of a specific wavelength such as visible light or near infrared light can be controlled by controlling the refractive index and film thickness of each layer using the relationship represented by the above formula. For example, the reflectance in a specific wavelength region can be improved by controlling the refractive index, film thickness, and lamination state of each layer. As a result, the reflectance at a specific wavelength λ can be increased.

The optical reflective film 10 preferably has an average spectral reflectance at a wavelength of 1000 to 1200 nm of 30% or more and less than 90%. The optical reflection film 10 can reflect heat rays (infrared light) more effectively as the average spectral reflectance at a wavelength of 1000 to 1200 nm is higher.

Further, the optical reflective film 10 preferably has a maximum spectral transmittance at a wavelength of 300 to 380 nm of 50% or less. The optical reflective film 10 is more transparent as the transmittance in the visible light region with a wavelength of 300 to 380 nm is higher. Therefore, the optical reflective film 10 is suitable as an optical film to be bonded to a window glass or the like with less decrease in visible light region or discoloration of transmitted light. ing.

As described above, the optical reflective film 10 adjusts the reflectance and transmittance of each wavelength in the reflective layer 12 by adjusting the thickness of the reflective layer 12 and the thickness of the high refractive index layer and the low refractive index layer. Can be adjusted. As a method of adjusting the film thickness in the reflective layer 12, the total number of high refractive index layers and low refractive index layers constituting the reflective layer 12 is N layers, and the layer closest to the base material 11 of the reflective layer 12 (lowermost layer) Is the first layer and the farthest layer (the outermost layer) is the Nth layer, at least one layer between the (N / 4) to (N / 2) layers is made thicker than the adjacent layers It is preferable. Particularly preferably, any one of the high refractive index layers between the (N / 4) to (N / 2) layers is preferably formed thicker than the adjacent layers, and is 1.2 times or more of the adjacent layers. It is more preferable to set it as the thickness.

For example, in the case of 21 layers (number of layers N = 21) of the reflective layer 12 composed of a low refractive index layer containing SiO ₂ and a high refractive index layer containing TiO ₂ , when the first layer is a low refractive index layer, The (N / 4) to (N / 2) layers are the 5th to 11th layers (the number of layers is rounded off to the nearest decimal place). A layer formed thicker than the adjacent layer is a tenth high refractive index layer (thickness 230 nm). Further, the film thicknesses of the ninth layer and the eleventh layer adjacent thereto are set to 150 nm or the like. At this time, all the low refractive index layers have the same thickness (150 nm), and all the high refractive index layers other than the thickly formed layer (10th layer) have the same thickness (120 nm). Thus, by forming the reflective layer 12, the above-described average spectral reflectance at a wavelength of 1000 to 1200 nm and maximum spectral transmittance at a wavelength of 300 to 380 nm can be achieved.

Further, in the reflective layer 12, the layer (lowermost layer) provided closest to the substrate 11 preferably contains a polymer compound having a glass transition temperature of 0 ° C. or lower. In particular, a polymer compound having a urethane bond (urethane resin) is preferably used as the polymer compound having a glass transition temperature of 0 ° C. or lower. By including a polymer compound having a glass transition temperature of 0 ° C. or less in the layer closest to the base material 11, the adhesion between the base material 11 and the reflective layer 12 is maintained even after the light resistance test.

Generally, it has been conventionally known that a high Tg polymer compound such as urethane resin has higher adhesion to various materials than other resins. However, these polymer compounds are more deteriorated by ultraviolet rays than other resins. For this reason, in an optical reflective film using a polymer compound having a low Tg such as urethane resin, the optical reflective film is likely to break due to long-term use.

On the other hand, in the configuration of the optical reflective film 10, the reflective layer 12 is disposed between the first ultraviolet absorbing layer 13 and the second ultraviolet absorbing layer (base material 11). For this reason, in the optical reflection film 10, ultraviolet rays from the front surface side are absorbed by the first ultraviolet absorption layer 13, and ultraviolet rays from the back surface side are absorbed by the substrate 11 (second ultraviolet absorption layer). It is possible to greatly suppress the deterioration of the polymer compound due to. That is, in the configuration of the optical reflection film 10, by suppressing the light deterioration of the low Tg polymer compound in the reflection layer 12, the effect of improving the adhesion between the base material 11 and the reflection layer 12 by the low Tg polymer compound is obtained. It can be maintained over a long period of time.

Therefore, by using a low Tg polymer compound such as urethane resin in the lowermost layer of the reflective layer 12, even in the optical reflective film 10 after long-term use, the substrate 11 and the reflective layer 12 with the low Tg polymer compound are used. High adhesion is maintained. For this reason, in the replacement | exchange operation | work of the optical reflection film 10, etc., the peeling with the base material 11 and the reflection layer 12 at the time of peeling the optical reflection film 10 by the adhesive fall of the base material 11 and the reflection layer 12 is suppressed. The breakage of the optical reflective film 10 can be suppressed.

The thickness of the reflective layer 12 composed of alternating layers of high refractive index layers and low refractive index layers is not particularly limited, and is preferably 10 μm or less, more preferably 5.5 μm or less, and particularly preferably 1.0 to 4. The range is 0 μm. When the thickness of the reflective layer is 10 μm or less, particularly 5.5 μm or less, it is easy to perform construction on a window or the like. Moreover, by making the film thickness of the reflective layer 12 within the above range, it is possible to effectively prevent the film from being bent even when the weather resistance, in particular, the optical reflective film 10 repeats thermal expansion and thermal contraction. Later, it is possible to prevent peeling of the end portion for a long period of time.

The thickness (thickness after drying) of the high refractive index layer and the low refractive index layer constituting the reflective layer 12 is preferably 20 to 1000 nm, more preferably 50 to 500 nm, More preferably, it is 100 to 300 nm, and particularly preferably 100 to 200 nm. The thicknesses of the high refractive index layer and the low refractive index layer may be the same or different. Moreover, the thickness per layer of each layer can be confirmed by, for example, cutting the manufactured reflective layer 12 and observing the cut surface with an electron microscope. At this time, when the interface between the two layers cannot be clearly observed, the interface can be determined by the XPS profile in the thickness direction obtained by an XPS (X-ray Photoelectron Spectroscopy) surface analyzer.

[High refractive index layer]
The high refractive index layer contains a polymer and metal oxide fine particles. Further, the high refractive index layer preferably contains titanium oxide as metal oxide fine particles. The high refractive index layer may contain metal oxide fine particles and inorganic oxide fine particles other than titanium oxide together with titanium oxide.

(Water-soluble polymer)
As the polymer contained in the high refractive index layer, it is preferable to use a water-soluble polymer that functions as a binder. When the high refractive index layer contains a water-soluble polymer, it is possible to form a layer that suppresses the use of an organic solvent, and to solve environmental problems due to the organic solvent. Moreover, a softness | flexibility can be provided to a coating film by using water-soluble polymer.

When a water-soluble polymer is used as the polymer contained in the high refractive index layer, a liquid layer deposition method such as coating or spin coating can be applied to the formation of the high refractive index layer. The liquid layer film forming method is simpler than the gas phase film forming method, and is effective for the production of the optical reflective film 10 using a resin film because the heat resistance of the substrate is not questioned. Further, by using a coating method, a mass production method such as a roll-to-roll method can be adopted, which is advantageous in terms of cost and process time.

Examples of the water-soluble polymer include polyvinyl alcohol and derivatives thereof (polyvinyl alcohol resin), gelatin, thickening polysaccharides, and the like. From the viewpoint of coating unevenness and film thickness uniformity (haze), the high refractive index layer preferably contains polyvinyl alcohol or a derivative thereof as a polymer. Examples of the polyvinyl alcohol resin include various modified polyvinyl alcohols in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate. A polymer may be used independently and may be used in combination of 2 or more type. The polymer may be a synthetic product or a commercially available product.

Incidentally, the polymer used for the high refractive index layer is not limited to the above-mentioned materials, for example, known polymers described in International Publication Nos. 2012/128109, JP2013-121567A, JP2013-148849A, and the like. Polymers can also be used.

Polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 1000 or more, and particularly preferably has an average degree of polymerization of 1500 to 5000. The degree of saponification is preferably 70 to 100 mol%, particularly preferably 80 to 99.9 mol%. As such polyvinyl alcohol, for example, JP-45 (degree of polymerization 4500, degree of saponification 88 mol%) manufactured by Nippon Vinegar Poval can be used.

Examples of the modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, and vinyl alcohol polymers. In addition, vinyl acetate resin (for example, “Exeval” manufactured by Kuraray Co., Ltd.), polyvinyl acetal resin obtained by reacting polyvinyl alcohol with aldehyde (for example, “S Lecque” manufactured by Sekisui Chemical Co., Ltd.), silanol-modified polyvinyl having silanol group Alcohol (for example, “R-1130” manufactured by Kuraray Co., Ltd.), modified polyvinyl alcohol resin having an acetoacetyl group in the molecule (for example, “Gosefimer (registered trademark) Z / WR series” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Etc. are also included in the modified polyvinyl alcohol.

Examples of the anion-modified polyvinyl alcohol include polyvinyl alcohols having an anionic group described in JP-A-1-206088, vinyl alcohols described in JP-A-61-237681 and JP-A-63-307979. Examples thereof include a copolymer with a vinyl compound having a water-soluble group, and a modified polyvinyl alcohol having a water-soluble group described in JP-A-7-285265.

Nonionic modified polyvinyl alcohols include, for example, polyvinyl alcohol derivatives in which a polyalkylene oxide group described in JP-A No. 7-9758 is added to a part of vinyl alcohol, and hydrophobic properties described in JP-A No. 8-25795. Examples thereof include a block copolymer of a vinyl compound having a group and vinyl alcohol, a silanol-modified polyvinyl alcohol having a silanol group, and a reactive group-modified polyvinyl alcohol having a reactive group such as an acetoacetyl group, a carbonyl group, or a carboxyl group.

As the cation-modified polyvinyl alcohol, for example, polyvinyl alcohol having a primary to tertiary amino group or a quaternary ammonium group described in JP-A-61-10483 in the main chain or side chain of the polyvinyl alcohol. And can be obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

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

As the ethylene-modified polyvinyl alcohol, for example, those described in JP2009-107324A, JP2003-248123A, JP2003-342322A, and the like can be used. Alternatively, commercially available products such as EXEVAL (trade name: manufactured by Kuraray Co., Ltd.) may be used.

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

In addition, the above-mentioned polyvinyl alcohol may be used alone or in combination of two or more. Polyvinyl alcohol may be a synthetic product or a commercial product.

The weight average molecular weight of polyvinyl alcohol is preferably 1000 to 200000, more preferably 3000 to 60000. In addition, the value measured by the static light scattering method, the gel permeation chromatograph method (GPC), TOFMASS, etc. can be employ | adopted for the value of a "weight average molecular weight". When the weight average molecular weight of the water-soluble polymer is within the above range, the application method can be applied and the productivity can be improved.

The content of the water-soluble polymer in the high refractive index layer is preferably 5 to 75% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the high refractive index layer. When the content of the water-soluble polymer is 5% by mass or more, when a high refractive index layer is formed by a wet film forming method, it is possible to suppress a decrease in transparency due to disturbance of the film surface when the coating film is dried. On the other hand, when the content of the water-soluble polymer is 75% by mass or less, a suitable range is obtained when the metal oxide particles are contained in the high refractive index layer.

In addition, content of water-soluble polymer is calculated | required from the residual solid content of an evaporation-drying method. Specifically, the optical reflection film is immersed in hot water at 95 ° C. for 2 hours, and the remaining film is removed, and then the hot water is evaporated, and the amount of the obtained solid matter is made the water-soluble high molecular weight. At this time, when one peak is observed in each of the regions of 1700 to 1800 cm ⁻¹ , 900 to 1000 cm ⁻¹ , and 800 to 900 cm ^{−1 in} the IR (infrared spectroscopy) spectrum, the water-soluble polymer is polyvinyl alcohol. It can be determined that

When the high refractive index layer contains a water-soluble polymer, a curing agent can be used to cure the water-soluble polymer. Curing agents include boric acid and its salts, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidylcyclohexane, N, N-diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl Ether, glycerol polyglycidyl ether, etc., aldehyde curing agents (formaldehyde, glyoxal, etc.), active halogen curing agents (2,4-dichloro-4-hydroxy-1,3,5, -s-triazine, etc.), active vinyl Examples of such compounds include 1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, aluminum alum and borax. The content of the curing agent in the high refractive index layer is preferably 1 to 10% by mass with respect to the solid content of the high refractive index layer.

The high refractive index layer may contain a surfactant for adjusting the surface tension during coating. Here, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, or the like can be used as the surfactant. As the surfactant, an anionic surfactant is preferably used, and one containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule is preferable. The content of the surfactant in the high refractive index layer is preferably 0.01 to 5% by mass with respect to the solid content of the high refractive index layer. As the surfactant, for example, Newcol series (manufactured by Nippon Emulsifier Co., Ltd.) can be used.

(Metal oxide fine particles; high refractive index layer)
The high refractive index layer preferably contains titanium oxide particles as metal oxide fine particles. The high refractive index layer may contain fine metal oxide particles other than titanium oxide together with titanium oxide. The high refractive index layer preferably has the largest proportion of titanium oxide as metal oxide fine particles. Preferably, in all the particles, it is preferable to contain 50% by mass or more of titanium oxide, more preferably 70% by mass or more of titanium oxide, and more preferably 80% by mass or more of titanium oxide. As the titanium oxide, titanium dioxide is preferable because a transparent and higher refractive index layer having a higher refractive index can be formed. In particular, rutile (tetragonal) titanium oxide particles are preferably used.

The content of the metal oxide particles in the high refractive index layer is preferably 20 to 80% by mass with respect to 100% by mass of the solid content of the high refractive index layer from the viewpoint of heat ray shielding and color unevenness reduction. 30 to 75% by mass is more preferable, and 40 to 70% by mass is more preferable.

Examples of the metal oxide fine particles include Ti, Li, Na, Mg, Al, Si, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, and Nb. , Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and one or more selected from the group consisting of rare earth metals Metal oxides can be used. One kind or two or more kinds of metal oxide particles may be used.

Examples of the metal oxide particles used in the high refractive index layer include zirconium oxide (ZrO ₂ ), zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, and ferric oxide. , Iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, hafnium oxide, niobium oxide, tantalum oxide (Ta ₂ O ₅ ), barium oxide, indium oxide, europium oxide, lanthanum oxide, zircon, Examples thereof include tin oxide, lead oxide, and double oxides thereof such as lithium niobate, potassium niobate, lithium tantalate, and aluminum / magnesium oxide (MgAl ₂ O ₄ ).

Examples of rare earth oxides include scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, and oxide. Thulium, ytterbium oxide, lutetium oxide, or the like can be used.

The metal oxide particles used in the high refractive index layer are preferably metal oxide particles having a refractive index of 1.90 or more. Examples of the metal oxide particles having a refractive index of 1.90 or more include zirconium oxide, cerium oxide, titanium oxide, and zinc oxide.

Further, as the metal oxide particles used in the high refractive index layer, a structure in which aluminum, silicon, zirconium or the like is supported on the surface of the metal oxide particles in an island shape having a three-dimensional barrier can be used. For example, the titanium oxide fine particles may be core-shell particles coated with a silicon-containing hydrated oxide. The core-shell particle has a structure in which a shell layer of silicon-containing hydrated oxide is coated on the surface of metal oxide particles (titanium oxide particles) serving as a core. By using such core-shell particles for the high refractive index layer, mixing at the interface between adjacent layers is suppressed by the interaction between the silicon-containing hydrated oxide of the shell layer and the water-soluble resin. Here, the “coating” indicates a state in which the 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 metal oxide particles may be completely covered with the silicon-containing hydrated oxide, and the silicon-containing hydrated oxide adheres to a part of the surface of the titanium oxide particles. It may be in a state. Since the refractive index of the core-shell particles is affected 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. In the following, such coated titanium oxide core-shell particles are also referred to as “silica-attached titanium dioxide sol”. As a method of coating 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- The method described in Japanese Patent No. 246351 can be applied.

The volume average particle size of the metal oxide particles used for the high refractive index layer is preferably 100 nm or less, and more preferably 50 nm or less. In particular, since the haze value is low and the visible light transmittance is excellent, the volume average particle diameter is preferably 1 to 30 nm, more preferably 1 to 20 nm.

Here, the volume average particle diameter is an average value obtained by measuring the particle diameters of 1000 arbitrary particles by a method of observing the particles themselves. For the measurement of particle size, for example, a laser diffraction scattering method, a dynamic light scattering method, a method of observing using an electron microscope, or a method of observing a particle image appearing on a cross section or surface of a layer with an electron microscope. Use. And about 1000 arbitrary particles measured by these methods, there are n1, n2,..., Ni, nk particles having particle diameters of d1, d2,. In the existing population, when the volume per particle is vi, the average particle size mv = the value represented by {Σ (vi · di)} / {Σ (vi)} The diameter.

[Low refractive index layer]
The low refractive index layer includes a polymer. Further, the low refractive index layer may contain metal oxide fine particles and inorganic oxide fine particles as necessary.

Examples of the polymer contained in the low refractive index layer include the same polymers as those described in the description of the high refractive index layer. Further, the polymer contained in the low refractive index layer is preferably a water-soluble polymer as in the above-described high refractive index layer. The polymer contained in the low refractive index layer may be the same component as the high refractive index layer or may be a different component, but is preferably different. Further, the low refractive index layer may contain a curing agent for curing the water-soluble polymer and a surfactant. Also for these, the same material as the above-described high refractive index layer can be used.

(Inorganic fine particles; low refractive index layer)
The low refractive index layer may be configured to include fine particles (inorganic fine particles) such as inorganic oxide fine particles, metal compound fine particles, and metal oxide fine particles together with the water-soluble polymer. Since the high refractive index layer and the low refractive index layer both contain inorganic fine particles, the refractive index can be easily adjusted. For this reason, it is possible to increase the refractive index of the high refractive index layer, the low refractive index layer, and the thickness of the reflective layer 12 by reducing the number of stacked layers. By reducing the number of layers of the reflective layer 12, productivity can be improved and a decrease in transparency due to scattering at the stack interface can be suppressed.

Examples of the inorganic oxide particles and metal compound fine particles used for the low refractive index layer include silicon dioxide (SiO ₂ ), magnesium fluoride (MgF ₂ ), etc., preferably using silicon dioxide, particularly using colloidal silica. It is particularly preferred. Examples of the metal oxide fine particles used for the low refractive index layer include the same materials as the metal oxide fine particles described for the high refractive index layer.

The inorganic fine particles contained in the low refractive index layer preferably have an average particle size of 3 to 100 nm. The average particle size of the inorganic fine particles dispersed in the primary particle state (particle size in the dispersion state before coating) is more preferably 3 to 50 nm, further preferably 3 to 40 nm, particularly preferably 3 to 20 nm. Most preferred is ˜10 nm. Moreover, as an average particle diameter of secondary particle | grains, 30 nm or less is preferable from a viewpoint with few hazes and being excellent in visible light transmittance | permeability. The average particle size of the inorganic fine particles in the low refractive index layer is determined by observing the particles themselves or particles appearing on the cross section or surface of the low refractive index layer with an electron microscope and measuring the particle size of 1000 arbitrary particles. And it calculates | requires as the simple average value (number average). Here, the particle size of each particle is a circle diameter (area circle equivalent diameter) when a circle having an area equal to the projected area of the particle is assumed.

The content of the inorganic fine particles in the low refractive index layer is preferably 5 to 70% by mass and preferably 10 to 50% by mass with respect to the solid content of the low refractive index layer from the viewpoint of refractive index. Further preferred.

Colloidal silica is obtained by heat-ripening a silica sol obtained by metathesis with an acid such as sodium silicate or passing through an ion exchange resin layer. Colloidal silica is disclosed in, for example, JP-A-57-14091, JP-A-60-219083, JP-A-60-219084, JP-A-61-20792, JP-A-61-188183. JP-A-63-17807, JP-A-4-93284, JP-A-5-278324, JP-A-6-92011, JP-A-6-183134, JP-A-6-297830, Manufacturing methods and configurations described in JP-A-7-81214, JP-A-7-101142, JP-A-7-179029, JP-A-7-137431, and International Publication No. 94/26530 Can be applied. Such colloidal silica may be a synthetic product or a commercially available product. The surface of the colloidal silica may be cation-modified, or may be treated with Al, Ca, Mg, Ba or 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.

In addition to the above, each layer is composed of, for example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, and JP-A-57-74192. JP-A 57-87989, JP-A 60-72785, JP-A 61-14659, JP-A-1-95091, JP-A-3-13376, etc. Anti-fading agent, described in JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-242871, and JP-A-4-219266 Fluorescent brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate and other pH adjusters, antifoaming agents, diethylene glycol, etc. Lubricants, preservatives, anti-static agents may also contain various known additives such as a matting agent. The content of these additives is preferably 0.1 to 10% by mass with respect to the solid content of the low refractive index layer.

[First UV absorbing layer]
The first ultraviolet absorption layer 13 includes an ultraviolet absorber. The first ultraviolet absorbing layer 13 includes a polymer material that serves as a binder for the ultraviolet absorber in addition to the ultraviolet absorber. As the polymer material that becomes the binder of the first ultraviolet absorption layer 13, the water-soluble polymer that constitutes the reflection layer 12 described above can be used.

The first ultraviolet absorbing layer 13 preferably contains 0.05 to 15% by mass of an ultraviolet absorber. Further, it is preferable that 1 to 10% by mass of an ultraviolet absorber is contained.
The thickness of the first ultraviolet absorbing layer 13 is preferably 1 μm to 30 μm. By setting the thickness to 1 μm or more, the film forming property of the first ultraviolet absorbing layer 13 can be improved, and the ultraviolet absorbing ability required for the first ultraviolet absorbing layer 13 can be easily added. On the other hand, when the thickness exceeds 30 μm, not only the cost becomes high, but also a time is required for the drying process in the production, and the production becomes difficult.

Moreover, the 1st ultraviolet absorption layer 13 can also be set as the structure which serves as the adhesion layer of the optical reflection film 10 by including materials which have adhesiveness, such as an adhesive. In the case where the first ultraviolet absorbing layer 13 functions as an adhesive layer, an adhesive material can be used as a binder. Moreover, when making the 1st ultraviolet absorption layer 13 function as an adhesion layer, the well-known release paper may further be provided on the adhesion layer.

Examples of the adhesive material include a dry laminating agent, a wet laminating agent, an adhesive, a heat seal agent, and a hot melt agent. Especially, it is preferable that an adhesion layer contains an adhesive as an adhesive material. Examples of adhesives include acrylic adhesives, silicone adhesives, urethane adhesives, polyvinyl butyral adhesives, polyester resins, polyvinyl acetate resins, nitrile rubber, and ethylene-vinyl acetate adhesives. Can do. In particular, in applications where the optical reflective film 10 is bonded to a window glass, a method in which water is sprayed on the window and the adhesive layer side of the optical reflective film 10 is bonded to a wet glass surface, the so-called water bonding method is preferable. Used for. For this reason, it is preferable to use an acrylic pressure-sensitive adhesive having a low adhesive strength in the presence of water.

When the first ultraviolet absorbing layer 13 also serves as an adhesive layer, the thickness is preferably in the range of 1 to 30 μm, more preferably in the range of 5 to 20 μm. Since the adhesive force depends on the thickness of the adhesive layer, the adhesive layer needs to have a certain thickness. When the pressure-sensitive adhesive layer is less than 1.0 μm, for example, partial contact with an adhesive surface with glass or the like becomes insufficient, and it is difficult to obtain a necessary pressure-sensitive adhesive force. Further, when the thickness of the adhesive layer exceeds 30 μm, not only the cost becomes high, but also after being attached to glass and then peeled off, cohesive failure occurs between the adhesive layers, and the adhesive remains.

(UV absorber)
The ultraviolet absorber used for the 1st ultraviolet absorption layer 13 is not specifically limited, A well-known ultraviolet absorber can be used. For example, benzophenone compounds such as 2,4-dihydroxy-benzophenone and 2-hydroxy-4-methoxy-benzophenone, 2- (2′-hydroxy-5-methylphenyl) benzotriazole, 2- (2′-hydroxy-3) Benzotriazole compounds such as', 5'-di-t-butylphenyl) benzotriazole, phenyl salicylate, 2-4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxy Salicylic acid phenyl compounds such as benzoate, hindered amine compounds such as bis (2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) ) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-ethoxyphene) And triazine compounds such as (nyl) -1,3,5-triazine.
In particular, the ultraviolet absorber preferably contains at least one selected from benzotriazole compounds, triazine compounds, and benzophenone compounds.

In addition to the above, the ultraviolet absorber includes a compound having a function of converting the energy held by ultraviolet light into vibrational energy in the molecule and releasing the vibrational energy as thermal energy.

In addition, you may use an ultraviolet absorber individually or in mixture of 2 or more types. Moreover, as the ultraviolet absorber, a synthetic product or a commercially available product may be used. Examples of commercially available products include, for example, Tinuvin (registered trademark) 320, Tinuvin (registered trademark) 328, Tinuvin (registered trademark) 234, Tinuvin (registered trademark) 477, Tinuvin (registered trademark) 1577, and Tinuvin (registered trademark) 622. (Above, manufactured by BASF Japan Ltd.), ADK STAB (registered trademark) LA-31 (above, manufactured by ADEKA CORPORATION), SEESORB (registered trademark) 102, SESORB (registered trademark) 103, SEESORB (registered trademark) 501 (or more, Cipro Kasei Co., Ltd.).

[Base material (second ultraviolet absorbing layer)]
In the optical reflection film 10, the base material 11 is configured as the second ultraviolet absorption layer of the optical reflection film 10 by including an ultraviolet absorber in the base material 11. As the ultraviolet absorber contained in the substrate 11, the ultraviolet absorber described in the first ultraviolet absorbing layer 13 can be used.

By causing the substrate 11 to function as the second ultraviolet absorbing layer, not only direct light incident from the first ultraviolet absorbing layer 13 side but also light incident from the substrate 11 side due to irregular reflection or the like. The incidence of ultraviolet rays into the optical reflection film 10 can be suppressed. In this way, by sandwiching the reflective layer 12 with a layer containing an ultraviolet absorber, it is possible to suppress deterioration of the reflective layer 12 and the substrate 11 due to ultraviolet rays, and to suppress discoloration of the reflective layer 12. Is possible.

In the optical reflective film 10, the base material 11 is not particularly limited as long as it is a base material formed of a transparent organic material. Examples of the substrate 11 include polyolefin films (polyethylene, polypropylene, etc.), polyester films (polyethylene terephthalate, polyethylene naphthalate, etc.), polyvinyl chloride, cellulose triacetate, polyimide, polybutyral film, cycloolefin polymer film, transparent Examples of resin materials such as cellulose nanofiber film can be given. Furthermore, two or more layers of these resin materials can be laminated and used.

As the substrate 11, a polyester film is preferably used. In particular, from the viewpoint of transparency, mechanical strength, dimensional stability among polyester films, dicarboxylic acid components such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, and ethylene glycol and 1,4-cyclohexanedimethanol It is preferable to have a film-forming property having a diol component as a main constituent. Specifically, a polyester mainly composed of polyethylene terephthalate or polyethylene naphthalate, a copolymer polyester composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and two or more kinds of these polyesters It is preferable that the mixture is a major constituent.

As the base material 11 containing an ultraviolet absorber, a commercially available product can be used. For example, Teijin Tetron film HB (registered trademark) manufactured by Teijin DuPont Films, Inc. can be used.

The substrate 11 may be an unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.
The thickness of the substrate is preferably in the range of 5 to 200 μm, more preferably 15 to 150 μm.
The base material 11 preferably has a visible light region transmittance of 85% or more as shown in JIS R3106-1998, and particularly preferably 90% or more. By increasing the transmittance of the substrate 11, the minimum transmittance of the optical reflective film 10 at a wavelength of 420 to 780 nm can be increased.

The base material 11 can be manufactured by a conventionally known general method. For example, it can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding and the like. In addition, a stretched film may be prepared from an unstretched resin base material using a known method such as uniaxial stretching, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular simultaneous biaxial stretching, or the like. it can. The draw ratio in this case can be appropriately selected according to the resin as a raw material, but is preferably 2 to 10 times in the vertical axis direction and the horizontal axis direction.

Further, the base material 11 may be subjected to a relaxation treatment or an offline heat treatment in terms of dimensional stability. The relaxation treatment is preferably carried out in the process from the heat setting in the stretching process of the polyester film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature of 80 to 200 ° C., more preferably a treatment temperature of 100 to 180 ° C. In addition, the relaxation rate is preferably in the range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably in the range of 2 to 6%. The base material 11 subjected to the relaxation treatment is improved in heat resistance by performing off-line heat treatment, and further has good dimensional stability.

[Method for producing optical reflection film]
Next, the manufacturing method of the above-mentioned optical reflective film 10 is demonstrated. The optical reflective film 10 includes a step of forming the reflective layer 12 on the substrate 11 and a step of forming the first ultraviolet absorbing layer 13.

(Base material preparation)
First, the base material 11 containing an ultraviolet absorber is prepared. The base material 11 containing the ultraviolet absorber is prepared by mixing and melting the above-described resin applicable to the base material 11 and the above-described ultraviolet absorber, and further processing the resin containing the ultraviolet absorber into a pellet, It can produce by processing in a shape. Moreover, as the base material 11, you may use the resin base material containing a commercially available ultraviolet absorber.

For example, when polyester is used as the substrate 11, the polyester is produced by directly esterifying a dicarboxylic acid component and a glycol component. Alternatively, when a dialkyl ester of a dicarboxylic acid component is used, the polyester is prepared by transesterification with a glycol component and heating this under reduced pressure to remove excess glycol component. At this time, a transesterification catalyst or a polymerization catalyst is used as necessary. Moreover, stabilizers, such as a phosphorus compound, can be added.
Further, the obtained polyester is heated and melted at a temperature equal to or higher than the melting point of the polyester using a known melt extrusion apparatus represented by an extruder. Then, the molten polymer is continuously extruded from the slit-shaped base, and is forcedly cooled to produce the base material 11.
The UV absorber is mixed at any stage from polymer production to extrusion. In addition, other additives such as a crystal nucleating agent, an antioxidant, an anti-coloring agent, a pigment, a dye, a release agent, a lubricant, a flame retardant, an antistatic agent, and particles can be mixed at any stage.

(Reflective layer forming process)
Next, the reflective layer 12 is formed on the base material 11 containing an ultraviolet absorber. The method for forming the reflective layer 12 is not particularly limited. For example, there is a method for forming the reflective layer 12 by alternately applying and drying a coating solution for a high refractive index layer and a coating solution for a low refractive index layer. Can be mentioned.

The adjustment method of the coating liquid for the high refractive index layer is not particularly limited, and there is a method in which the water-soluble polymer, the metal oxide fine particles, the solvent, and other additives added as necessary are stirred and mixed. Can be mentioned. The method for adjusting the coating solution for the low refractive index layer is not particularly limited, and examples thereof include a method of stirring and mixing a water-soluble polymer, a solvent, and, if necessary, inorganic fine particles and other additives. . At the time of this stirring and mixing, the order of addition of each component is not particularly limited, and each component may be sequentially mixed while stirring, or may be mixed and stirred at one time. Each of these coating liquids is adjusted to an appropriate viscosity by adjusting the amount of the solvent.

Here, the solvent for adjusting each coating liquid is not particularly limited, but it is preferable to use water, an organic solvent, or a mixed solvent thereof. In consideration of environmental aspects due to scattering of the organic solvent, water or a mixed solvent of water and a small amount of an organic solvent is more preferable, and water is particularly preferable.

Examples of the organic solvent used in each coating solution include alcohols such as methanol, ethanol, 2-propanol, and 1-butanol, and esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. , Ethers such as diethyl ether, 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 standpoint of environment and ease of operation, the solvent for the coating solution is preferably a mixed solvent of water and methanol, ethanol, and ethyl acetate.

When a mixed solvent of water and a small amount of organic solvent is used, the content of water in the mixed solvent is preferably 80 to 99.9% by mass, based on 100% by mass of the entire mixed solvent, and preferably 90 to 99. More preferably, it is 5 mass%. By setting the water content to 80% by mass or more, volume fluctuation due to volatilization of the solvent can be reduced, and the operability of coating film formation is improved. Moreover, the homogeneity of a coating liquid increases by making content of water 99.9 mass% or less, and the physical property of a coating liquid is stabilized.

Next, each prepared coating liquid is applied onto the substrate 11 and dried. By performing the coating process and the drying process, a reflective layer can be formed from the coating film.
The coating method is not particularly limited and may be either a sequential coating method or a simultaneous multilayer coating, but is preferably a simultaneous multilayer coating from the viewpoint of productivity and the like. As the coating method, for example, a curtain coating method, a slide bead coating method using a hopper described in US Pat. No. 2,761,419, and US Pat. No. 2,761791, an extrusion coating method, and the like are preferably used.

When the slide bead coating method is used, the temperature of each coating solution when performing simultaneous multilayer coating is preferably a temperature range of 25 to 60 ° C., more preferably a temperature range of 30 to 45 ° C. When using the curtain coating method, a temperature range of 25 to 60 ° C. is preferable, and a temperature range of 30 to 45 ° C. is more preferable.

The viscosity of each coating solution when performing simultaneous multilayer coating is not particularly limited. For example, when the slide bead coating method is used, it is preferably in the range of 5 to 100 mPa · s, preferably in the range of 10 to 50 mPa · s, in the preferable temperature range of each of the above coating liquids. More preferred. When the curtain coating method is used, it is preferably in the range of 5 to 1200 mPa · s, and more preferably in the range of 25 to 500 mPa · s, in the preferable temperature range of the coating liquid. . If it is the range of such a viscosity, simultaneous multilayer coating can be performed efficiently.

The viscosity at 15 ° C. of each coating solution is preferably 100 mPa · s or more, more preferably 100 to 30000 mPa · s, still more preferably 3000 to 30000 mPa · s, and most preferably 10,000 to 30000 mPa · s. It is.

When the reflective layer 12 is formed by the sequential coating method, either the low refractive index layer coating solution or the high refractive index layer coating solution heated to 30 to 60 ° C. is used as the base layer. After coating and drying on the material 11 to form a layer, the other coating liquid is coated on this layer and dried to form a layer. The reflection layer 12 is formed by repeating this sequentially so that the number of layers necessary for expressing the desired reflection performance is obtained.

When drying, it is preferable to dry the formed coating film at 30 ° C. or higher. For example, it is preferable to dry in the range of a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 5 to 100 ° C. (preferably 10 to 50 ° C.). For example, hot air of 40 to 85 ° C. is blown for 1 to 5 seconds. dry. As a drying method, warm air drying, infrared drying, and microwave drying are used. In addition, drying in a multi-stage process is preferable to drying in a single process, and it is more preferable to set the temperature of the constant rate drying section <the temperature of the decreasing rate drying section. In this case, the temperature range of the constant rate drying section is preferably 30 to 60 ° C., and the temperature range of the decreasing rate drying section is preferably 50 to 100 ° C.

When the reflective layer 12 is formed by simultaneous multilayer coating, each coating solution is heated to 30 to 60 ° C., and after the simultaneous multilayer coating of each coating solution is performed on the substrate 11. 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 50 ° C. For example, it is dried by blowing warm air at 80 ° C. for 1 to 5 seconds. Moreover, as a cooling system immediately after coating, it is preferable to carry out by a horizontal set system from a viewpoint of the improvement of the uniformity of the formed coating film.

Here, the above set means that the viscosity of the coating composition is increased by reducing the temperature by applying cold air or the like to the surface of the coating film, and the fluidity of the substances in each layer is reduced or gelled. It means a process to be performed. When the finger is pressed against the surface of the coating film, the state in which the finger is no longer held is defined as the state of completion of setting.

The temperature of the cold air used in the setting process is preferably 0 to 25 ° C, more preferably 5 to 10 ° C. The time for which the coating film is exposed to cold air is preferably 10 to 360 seconds, more preferably 10 to 300 seconds, and further preferably 10 to 120 seconds, although it depends on the transport speed of the coating film.

The time (setting time) from the formation of the coating film to the completion of the setting by applying cold air is preferably within 5 minutes, and more preferably within 2 minutes. The lower limit time is not particularly limited, but is preferably 45 seconds or more. By providing a set time or longer, the components in the layer are sufficiently mixed. On the other hand, by setting the set time short, the interlayer diffusion of the metal oxide fine particles can be prevented, and a desired refractive index difference can be provided between the high refractive index layer and the low refractive index layer. In the case where high elasticity occurs quickly at the interface between the high refractive index layer and the low refractive index layer, a suitable interface can be formed without providing a setting step.

The set time includes various known concentrations such as gelatin, pectin, agar, carrageenan, gellan gum, as well as changing the concentration of water-soluble polymer contained in each coating solution and the concentration of metal oxide fine particles. It can be adjusted by adding other components such as a gelling agent.

(Ultraviolet absorption layer forming process)
The first ultraviolet absorbing layer 13 can be prepared by adjusting the ultraviolet absorbing layer coating solution and then coating and drying the coating solution.

The method for adjusting the ultraviolet absorbing layer coating liquid is not particularly limited, and the above-described ultraviolet absorbing material, water-soluble polymer, solvent, and additives and pressure-sensitive adhesives that are added as necessary are stirred and mixed. Is mentioned. At the time of mixing, the order of adding each component is not particularly limited, and each component may be sequentially mixed while stirring, or may be mixed and stirred at one time. Each of these coating liquids is adjusted to an appropriate viscosity by adjusting the amount of the solvent.

The solvent for adjusting the coating liquid is not particularly limited, and a solvent similar to the solvent used for forming the reflective layer 12 described above can be used. It is preferable to use water, an organic solvent, or a mixed solvent thereof. In consideration of environmental aspects due to scattering of the organic solvent, water or a mixed solvent of water and a small amount of an organic solvent is more preferable, and water is particularly preferable.

As a method for applying the ultraviolet absorbing layer coating solution, a known method can be used. For example, a die coater method, a gravure roll coater method, a blade coater method, a spray coater method, an air knife coat method, a dip coat method, and the like are preferable, and these can be used alone or in combination. Moreover, as a coating method of the ultraviolet absorbing layer coating liquid, the wet coating method that can be used for forming the reflective layer 12 may be used to directly coat the reflective layer 12.

In the case where the first ultraviolet absorbing layer 13 also serves as an adhesive layer, in addition to coating directly on the reflective layer 12, the first ultraviolet absorbing layer 13 is once coated on release paper and dried. The layer 13 may be transferred onto the reflective layer 12.

The drying temperature and time of the coating film are not specified, but it is preferable that the amount of the solvent remaining in the first ultraviolet absorption layer 13 after drying is small. For this reason, it is preferable to perform drying at a temperature of 50 to 150 ° C. for 10 seconds to 5 minutes. Moreover, when an adhesive is contained in the ultraviolet absorbing layer coating liquid, curing is necessary to obtain a stable adhesive force because the adhesive has fluidity. In general, when heated at room temperature for about one week or longer, for example, at about 50 ° C., three days or longer is preferable. In the case of heating, since the flatness of the base material 11 may deteriorate if the temperature is raised too much, it is preferable to carry out at a low temperature.

[Modification of optical reflection film]
Next, a modification of the optical reflection film of the first embodiment will be described. In FIG. 2, schematic structure of the optical reflection film of the modification of 1st Embodiment is shown.

The optical reflective film 10A shown in FIG. 2 includes a second ultraviolet absorbing layer 14, a base material 11A, a reflecting layer 12, and a first ultraviolet absorbing layer 13. The optical reflection film 10A is a side on which the first ultraviolet absorption layer 13 side is bonded to a window glass or the like, and the optical reflection film 10A from the first ultraviolet absorption layer 13 side mainly reflects on the reflection layer. The light including the wavelength is incident.

The optical reflective film 10A shown in FIG. 2 differs from the optical reflective film 10 of the first embodiment described above (see FIG. 1) only in that it includes the configuration of the base 11A and the second ultraviolet absorbing layer 14. Other configurations are the same as those in the first embodiment.

The substrate 11A is different from the optical reflecting film 10 (see FIG. 1) of the first embodiment only in that it does not need to contain an ultraviolet absorber. The optical reflective film 10A includes a second ultraviolet absorbing layer 14 on the back side of the base 11A. For this reason, even when the ultraviolet absorbent is not included in the substrate 11A, the ultraviolet rays from the back surface side can be absorbed by the second ultraviolet absorbing layer 14. As a result, deterioration (decomposition) of the base material 11A due to ultraviolet rays, deterioration of the reflective layer 12, and the like are suppressed, and breakage of the base material 11A when the optical reflective film 10A is exchanged can be suppressed.

The base material 11A may contain an ultraviolet absorber. In this case, the substrate 11 </ b> A also functions as an ultraviolet absorbing layer (third ultraviolet absorbing layer) together with the first ultraviolet absorbing layer 13 and the second ultraviolet absorbing layer 14. In such a configuration, an effect of suppressing breakage due to deterioration (decomposition) or the like of the base material 11A can be further expected.

As the 2nd ultraviolet absorption layer 14 provided in the back side of substrate 11A of optical reflective film 10A, the same composition as the above-mentioned 1st ultraviolet absorption layer 13 is applicable. That is, the second ultraviolet absorbing layer 14 can be configured using the same ultraviolet absorbent, polymer, or the like as the first ultraviolet absorbing layer 13 described above. Furthermore, it is good also as a layer provided with functions other than ultraviolet absorption using an adhesive.

Further, as the second ultraviolet absorbing layer 14, for example, a hard coat layer provided to protect the surface of the base material 11A, an anchor coat layer provided between the base material 11A and the hard coat layer, or the like is used. be able to. Further, the second ultraviolet absorbing layer 14 may be a layer other than the hard coat layer and the anchor coat layer, and is not particularly limited as long as the ultraviolet absorbing material can be held.

Further, the optical reflective film 10A can be manufactured by the same method as in the first embodiment described above. For example, the second ultraviolet absorbing layer 14 is produced on the one surface (back surface) side of the substrate 11 by the same method as the method of producing the first ultraviolet absorbing layer 13 described above. Further, when the second ultraviolet absorbing layer 14 is an anchor coat layer or a hard coat layer, when the anchor coat layer or the hard coat layer is formed on the back surface side of the base material 11A by a conventionally known method, It can be produced by mixing a UV absorber with the coating solution.

Further, after forming the second ultraviolet absorbing layer 14, the reflective layer 12 and the first ultraviolet absorbing layer 13 are formed on the other surface (front surface) side of the base 11A by the same method as in the first embodiment. To do. Thereby, the optical reflective film 10A provided with the 2nd ultraviolet absorption layer 14, the base material 11A, the reflection layer 12, and the 1st ultraviolet absorption layer 13 is producible.

<2. Embodiment of Optical Reflective Film (Second Embodiment)>
Next, a second embodiment of the optical reflection film will be described. A schematic configuration of the optical reflective film of the second embodiment is shown in FIG. In addition, the optical reflection film of 2nd Embodiment can apply the structure similar to the optical reflection film of the above-mentioned 1st Embodiment except that the form of lamination | stacking differs.

The optical reflective film 20 shown in FIG. 3 includes a first substrate 21 (second ultraviolet absorbing layer) containing an ultraviolet absorber, an adhesive layer 22, a reflective layer 23, a second substrate 24, and a first substrate. An ultraviolet absorbing layer 25 is provided. The optical reflection film 20 has a side on which the first ultraviolet absorption layer 25 is bonded to a window glass or the like, and the reflection from the first ultraviolet absorption layer 25 to the optical reflection film 20 is mainly intended for reflection on the reflection layer. The light including the wavelength is incident. In the following description, the surface on the first ultraviolet absorption layer 13 side of the optical reflecting film 20 is referred to as “front surface”, and the surface on the first base material 21 side of the optical reflecting film 20 is referred to as “back surface”.

In the optical reflective film 20, the reflective layer 23 is provided between the first base material 21 and the first ultraviolet absorbing layer 25. Further, the optical reflection film 20 includes a first base 21 (second ultraviolet absorption layer) containing an ultraviolet absorber on the opposite side of the reflective layer 23 from the first ultraviolet absorption layer 25.

The optical reflection film 20 bonds the second substrate 24 including the reflection layer 23 and the first ultraviolet absorption layer 25 and the first substrate 11 including the ultraviolet absorber via the adhesive layer 22. Can be produced. For example, the first ultraviolet absorbing layer 25 is formed on one surface (back surface) of the second substrate 24. In addition, the reflective layer 23 is formed on the other surface (surface) of the second substrate 24. Further, the adhesive layer 22 is formed on the reflective layer 23. And the 1st base material 21 containing an ultraviolet absorber is pasted together to the 2nd base material 24 via adhesion layer 22. Thereby, the 1st base material 21 (2nd ultraviolet absorption layer) containing a ultraviolet absorber, adhesion layer 22, reflective layer 23, 2nd substrate 24, and the 1st ultraviolet absorption layer 25 are arranged in this order. The optical reflection film 20 provided can be produced.

Examples of the ultraviolet absorber contained in the second ultraviolet absorbing layer include benzotriazole compounds, triazine compounds, and benzophenone compounds. It is preferable that a 2nd ultraviolet absorption layer contains at least 1 or more types chosen from said ultraviolet absorber. Moreover, it is preferable that the 1st ultraviolet absorption layer 25 also contains at least 1 type or more chosen from said ultraviolet absorber.

The reflective layer 23 preferably contains a polymer compound having a glass transition temperature of 0 ° C. or lower in a layer (lowermost layer) formed on and in contact with the second substrate 24 in contact with the reflective layer 23. Furthermore, the polymer compound having a glass transition temperature of 0 ° C. or lower preferably has a urethane bond.

In the optical reflection film 20, the first ultraviolet absorption layer 25 and the reflection layer 23 provided on the light incident side can have the same configuration as in the first embodiment. The first ultraviolet absorbing layer 25 may be provided with an adhesive layer and other functions as in the first embodiment. Moreover, in the optical reflection film 20, the 1st base material 21 used as the 2nd ultraviolet absorption layer provided in the backmost side is the group containing the ultraviolet absorber in the optical reflection film of the above-mentioned 1st Embodiment. A configuration similar to that of the material can be applied.

The 2nd base material 24 can apply the structure which does not contain an ultraviolet absorber from the above-mentioned 1st base material 21. FIG. In addition, the adhesive layer 22 may be configured to include a material having adhesive properties such as an adhesive in the above-described first ultraviolet absorbing layer 25 and not including an ultraviolet absorber. In addition, the 2nd base material 24 and the adhesion layer 22 may apply the structure containing the ultraviolet absorber like the 1st base material 21 and the 1st ultraviolet absorption layer 25 as it is.

[Modification of optical reflection film]
Next, a modification of the optical reflection film of the second embodiment will be described. In FIG. 4, schematic structure of the optical reflection film of the modification of 2nd Embodiment is shown. In addition, the modification of the optical reflection film of 2nd Embodiment is the same as the optical reflection film of the above-mentioned 2nd Embodiment except providing the 2nd ultraviolet absorption layer 26 on the back surface side of 21 A of 1st base materials. It is.

The optical reflective film 20A shown in FIG. 4 includes a second ultraviolet absorbing layer 26, a first base material 21A, an adhesive layer 22, a reflective layer 23, a second base material 24, and a first ultraviolet absorbing layer 25. Prepare. The optical reflection film 20A is a side on which the first ultraviolet absorption layer 25 side is bonded to a window glass or the like, and the optical reflection film 20A from the first ultraviolet absorption layer 25 side mainly reflects on the reflection layer. The light including the wavelength is incident.

The optical reflection film 20A differs from the optical reflection film 20 (see FIG. 3) of the above-described second embodiment only in that it includes the configuration of the first base material 21A and the second ultraviolet absorption layer 26, and others. The configuration is the same as that of the second embodiment described above.

The first base 21A is different from the optical reflective film 20 (see FIG. 1) of the second embodiment only in that it does not need to contain an ultraviolet absorber. The optical reflective film 20A includes a second ultraviolet absorbing layer 26 on the back side of the first base 21A. For this reason, even when the first base 21 </ b> A does not contain an ultraviolet absorber, the second ultraviolet absorbing layer 26 can absorb the ultraviolet rays from the back surface side. As a result, deterioration (decomposition) or the like of the first base material 21A and the second base material 24 due to ultraviolet rays is suppressed, and the first base material 21A when the optical reflecting film 20A is exchanged or the like is performed. And the fracture | rupture of the 2nd base material 24 can be suppressed.

Note that the first base material 21A may contain an ultraviolet absorber. In this case, the first base 21A also functions as an ultraviolet absorbing layer (third ultraviolet absorbing layer) together with the first ultraviolet absorbing layer 25 and the second ultraviolet absorbing layer 26. In such a configuration, an effect of suppressing breakage due to deterioration (decomposition) or the like of the first base material 21A and the second base material 24 can be further expected.

As the second ultraviolet absorbing layer 26 provided on the back surface side of the first base 21A of the optical reflecting film 20A, the same configuration as the first ultraviolet absorbing layer 25 described above can be applied. That is, the second ultraviolet absorbing layer 26 can be configured using the same ultraviolet absorbent, polymer, or the like as the first ultraviolet absorbing layer 25. Furthermore, it is good also as a layer provided with functions other than ultraviolet absorption using an adhesive.

Moreover, as the 2nd ultraviolet absorption layer 26, for example, it is provided between the hard coat layer provided in order to protect the surface of 21 A of 1st base materials, and the 1st base material 21A and a hard coat layer. An anchor coat layer or the like can be used. Further, the second ultraviolet absorbing layer 26 may be a layer other than the hard coat layer and the anchor coat layer, and is not particularly limited as long as it can hold the ultraviolet absorbing material.

<Preparation of Optical Reflective Film of Sample 101>
Sample 101 comprising an anchor coat layer (second ultraviolet absorption layer) containing an ultraviolet absorber, a substrate, a reflective layer A1, and an adhesive layer (first ultraviolet absorption layer) containing an ultraviolet absorber by the following method. An optical reflection film was prepared.

[Production of substrate]
The base material provided with the anchor coat layer (2nd ultraviolet absorption layer) containing an ultraviolet absorber with the following method was produced.
LR1730 (manufactured by Mitsubishi Rayon Co., Ltd., acrylic resin) (solid content 100%) 17 parts by mass, ethyl 2-cyano-3,3-diphenyl acrylate (product name: SEESORB 501, made by Cypro Kasei Co., Ltd.) 3 masses Part and 80 parts by mass of ethanol were added and dissolved to prepare an anchor coat layer coating solution.
Next, an anchor coat layer coating solution is applied to one surface (back surface) of a polyethylene terephthalate film (A4300 manufactured by Toyobo A4300: double-sided easy adhesion layer, width 160 mm, thickness 50 μm) so that the dry layer thickness becomes 2.0 μm. And applied using a wire bar. Furthermore, the coating film was dried to form an anchor coat layer, and a base material having an anchor coat layer (second ultraviolet absorption layer) containing an ultraviolet absorber was produced.

[Preparation of coating solution for high refractive index layer]
(Preparation of silica-attached titanium dioxide sol)
15.0% by mass of titanium oxide sol (SRD-W, volume average particle size: 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.) is added to 2 parts by mass of pure water and heated to 90 ° C. did. Next, 0.5 part by mass of an aqueous silicic acid solution (sodium silicate 4 (manufactured by Nippon Chemical Co., Ltd.) diluted with pure water so that the SiO ₂ concentration is 0.5 mass%) is gradually added and mixed. Furthermore, heat treatment was performed at 175 ° C. for 18 hours in an autoclave. And after cooling, it concentrates with an ultrafiltration membrane, Titanium dioxide sol (hereinafter referred to as silica-attached titanium dioxide sol) in which SiO ₂ having a solid content concentration of 6% by mass was attached to the surface (volume average particle size: 9 nm) Got.

(Adjustment of high refractive index layer coating solution)
To 113 parts by mass of the silica-attached titanium dioxide sol (20% by mass), 48 parts by mass of an aqueous citric acid solution (1.92% by mass) was added, and ethylene modified polyvinyl alcohol (Kuraray Co., Ltd. Exval RS-2117, saponification) was added. Degree: 97.5 to 99 mol%, ethylene modification degree: 3.0 mol%, polymerization degree: 1700, viscosity (4%, 20 ° C.): 23.0 to 30.0 (mPa · s), 8% by mass) Was added and stirred, and finally 0.4 parts by mass of a 5% by weight aqueous surfactant solution (Softazoline LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) was added to prepare a high refractive index layer coating solution.
The refractive index of the layer formed using the high refractive index layer coating solution was 1.80. The method for measuring the refractive index will be described later (the same applies to other layers).

[Preparation of coating solution for low refractive index layer]
A coating solution for a low refractive index layer was prepared as follows.
31 parts by mass of an acidic colloidal silica 10% by mass aqueous solution (Snowtex OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) is heated to 40 ° C., and 3 parts by mass of boric acid 3% by mass aqueous solution is added. Further, as a water-soluble resin, 39 parts by mass of a polyvinyl alcohol 6 mass% aqueous solution (PVA-224, polymerization degree: 2400, saponification degree: 87 mol%, manufactured by Kuraray Co., Ltd.) and 1 part by mass of a surfactant 5 A mass% aqueous solution (Softazoline LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) was added in this order at 40 ° C. to prepare a low refractive index layer coating solution.
The layer formed using the low refractive index layer coating solution had a refractive index of 1.50.

[Production of Reflective Layer A1]
The high refractive index layer coating solution and the low refractive index layer coating solution prepared above were each adjusted to 40 ° C. using a slide hopper coating device capable of six-layer multilayer coating. Then, on the other surface (surface) of the base material having the anchor coat layer (second ultraviolet absorption layer) containing the above-described ultraviolet absorber heated to 40 ° C., the outermost layer and the lowermost layer have a low refractive index. As the layers, a high refractive index layer and a low refractive index layer were alternately applied, and a total of 6 layers [low / low / high / low / high / low] were simultaneously applied. In the simultaneous multilayer coating, the low refractive index layer was 150 nm after drying, and the high refractive index layer was 130 nm after drying.
Next, after setting (thickening) 10 ° C. cold air immediately after coating, 60 ° C. warm air was blown and dried to produce a reflective layer A1. Each layer constituting the reflective layer is to determine the abundance of the high refractive index material cutting surface to cut the optical reflection film samples by XPS surface analyzer (TiO ₂₎ and the low refractive index material (SiO ₂₎ Thus, it was confirmed that the film thickness of each of the above layers was secured.

[Formation of adhesive layer]
An adhesive layer coating solution was prepared according to the following formulation.
-Adhesive: N2147 manufactured by Nippon Synthetic Chemical Industry (solid content 35% by mass) 100 parts by mass-UV absorber manufactured by BASF Tinuvin 477 (solid content 80% by mass) 2.1 parts by mass-Isocyanate-based curing agent manufactured by Nippon Polyurethane Industry Coronate L55E (solid content 55% by mass) 5 parts by mass The above-mentioned adhesive layer coating solution was used as a separator SP-PET (brand: PET-O2-BU) (made by Mitsui Chemicals, Inc.), which is a release film (release layer). The surface was coated with a comma coater so that the dry film thickness was 10 μm, and dried at 80 ° C. for 1 minute. And the peeling film which apply | coated the adhesion layer coating liquid was laminated | stacked with respect to reflective layer A1, and the adhesion layer (1st ultraviolet absorption layer) containing a ultraviolet absorber was formed on reflective layer A1.

<Preparation of Optical Reflective Film of Sample 102>
The base material (2nd ultraviolet absorption layer) containing an ultraviolet absorber was produced with the following method. Then, a reflective layer A1 and a pressure-sensitive adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber are produced on the substrate in the same manner as the above-described sample 101, and the substrate containing the ultraviolet absorber. An optical reflective film of the sample 102 including the (second ultraviolet absorbing layer), the reflective layer A1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber was produced.

[Production of substrate]
After 10 kg of polybutylene terephthalate / dodecanedicarboxylic acid copolymer resin was vacuum dried at 150 ° C. for 3 hours, ethyl 2-cyano-3,3-diphenyl acrylate (cyanoacrylate UV absorber, product name SEESORB 501, Cipro Kasei Co., Ltd.) (Manufactured by the company) 300 g was added and fed to a different-direction rotating twin-screw extruder and melted at 310 ° C. Then, it was extruded from a 3 mmφ die, quenched, and then cut into pellets to obtain a polyester containing an ultraviolet absorber. Furthermore, the obtained polyester was melted at 230 ° C. by a 40 mm diameter extruder, and casted electrostatically on a metal drum whose surface was maintained at 15 ° C. from a T die having a length of 160 mm and an interval of 1 mm. Then, the substrate was cooled and solidified to prepare a base material containing a UV absorber and made of a polyester film having a thickness of 25 μm.

<Preparation of Optical Reflective Film of Sample 103>
The anchor coat layer containing the UV absorber (secondary) is prepared in the same manner as the preparation of the optical reflective film of the sample 101 described above except that the base material containing the UV absorber prepared in the sample 102 is used as the substrate. Optical absorption of the sample 103 consisting of a base material (third ultraviolet absorption layer), a reflective layer A1, and an adhesive layer (first ultraviolet absorption layer) containing an ultraviolet absorber. A film was prepared.

<Preparation of Optical Reflective Film of Sample 104>
The base material which has the hard-coat layer (2nd ultraviolet absorption layer) which contains a ultraviolet absorber on the back side by the following method was produced. Then, on the surface of the base material, a reflective layer A1 and an adhesive layer containing a UV absorber (first UV absorber layer) are prepared in the same manner as in the preparation of the sample 101, and the UV absorber is added. An optical reflective film of sample 104 was prepared, which was composed of a hard coat layer (second ultraviolet absorbing layer), a base material, a reflective layer A1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber.

[Production of substrate]
The base material provided with the hard-coat layer (2nd ultraviolet absorption layer) containing an ultraviolet absorber with the following method was produced.

[Preparation of hard coat layer]
(Preparation of hard coat layer coating solution HC1)
The following components were mixed to prepare a coating liquid HC1.
YMF-02A (18 mass% Cs _0.33 WO ₃ dispersion, dispersant 10 mass%, average particle size 50 nm, manufactured by Sumitomo Metal Mining Co., Ltd.) 300 mass parts Aronix (registered trademark) M-402 (5, 6 functional acrylates, 5 functional components 35% by mass, manufactured by Toagosei Co., Ltd.) 100 parts by mass / Irgacure (registered trademark) 184 (manufactured by BASF Japan) 3 parts by mass / Irgacure (registered trademark) 819 (manufactured by BASF Japan) 3 parts by mass / ethyl 2-cyano-3,3-diphenyl acrylate (product name: SEESORB 501, manufactured by Cypro Kasei Co., Ltd.) 3 parts by mass / solvent: 165 parts by mass of MIBK (methyl isobutyl ketone)

(Formation of hard coat layer)
On one surface (back surface) of the substrate, the hard coat layer coating solution HC1 was applied with a gravure coater and dried at 90 ° C. for 1 minute. Next, a hard coat layer is formed by irradiating ultraviolet rays from the coated surface side using an ultraviolet lamp under the conditions of an illuminance of 100 mW / cm ² , an irradiation amount of 0.2 J / cm ² , and an oxygen concentration of 200 ppm. did. The thickness of the hard coat layer was adjusted to 2 μm.

<Preparation of Optical Reflective Film of Sample 105>
Except that the reflective layer A2 was produced by the following method, the base material (second ultraviolet absorbent layer) containing the ultraviolet absorbent, the reflective layer A2, and the ultraviolet absorbent was the same as the production of the sample 102 described above. An optical reflective film of Sample 105 consisting of an adhesive layer (first ultraviolet absorbing layer) containing an agent was prepared.

[Reflection layer A2]
(Preparation of low Tg resin-containing low refractive index layer coating solution [1])
A coating solution for a low refractive index layer containing a low Tg resin was prepared as follows.
13 parts by mass of an acidic colloidal silica 10% by mass aqueous solution (Snowtex OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) was heated to 40 ° C., and 3 parts by mass of boric acid 3% by mass aqueous solution was added. Furthermore, as a water-soluble resin, 35 parts by mass of a 6% by weight aqueous solution of polyvinyl alcohol (PVA-224, average degree of polymerization: 2400, degree of saponification: 87 mol%, manufactured by Kuraray Co., Ltd.) and a 6% by weight aqueous solution of water-dispersed acrylic resin 3 parts by weight (AE120A, Tg = −10 ° C., manufactured by Etec) and 1 part by weight of a 5% by weight aqueous solution of surfactant (Softafazoline LSB-R, manufactured by Kawaken Fine Chemicals) were added in this order at 40 ° C. A low Tg resin-containing low refractive index layer coating solution [1] was prepared.

(Preparation of reflective layer A2)
Using a slide hopper coating apparatus capable of six-layer coating, the high refractive index layer coating solution and the low refractive index layer coating solution prepared in the above-described sample 101, and the low refractive index containing low Tg resin adjusted by the above method The layer coating solution [1] was adjusted to 40 ° C., respectively. Then, on the other surface (surface) of the base material heated to 40 ° C., the lowermost layer is a low Tg resin-containing low refractive index layer, and a high refractive index layer and a low refractive index layer are alternately formed thereon. A total of 6 layers [low (low Tg) / low / high / low / high / low] were simultaneously applied. In the simultaneous multilayer coating, the low refractive index layer (including the low refractive index layer containing low Tg resin) is 150 nm after drying, and the high refractive index layer is 130 nm after drying. It was. Thereafter, the reflective layer A2 was produced in the same manner as the sample 101.

<Preparation of Optical Reflective Film of Sample 106>
An anchor coat containing an ultraviolet absorber in the same manner as in the preparation of the sample 101 described above, except that the reflective layer B1 is prepared by the following method and the thickness of the adhesive layer (first ultraviolet absorbing layer) is 10 μm. An optical reflective film of Sample 106 composed of a layer (second ultraviolet absorbing layer), a base material, a reflective layer B1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber was produced.

[Reflection layer B1]
The high refractive index layer coating solution and the low refractive index layer coating solution prepared in the above-described sample 101 were each adjusted to 40 ° C. using a slide hopper coating apparatus capable of 19 layer multilayer coating. Then, on the other surface (surface) of the substrate heated to 40 ° C., the outermost layer and the lowermost layer are used as the low refractive index layer, and the high refractive index layer and the low refractive index layer are alternately arranged, for a total of 19 layers. The simultaneous multilayer coating was performed. In the simultaneous multilayer coating, the low refractive index layer was 150 nm after drying, and the high refractive index layer was 130 nm after drying.
Next, immediately after application, 10 ° C. cold air was blown to set (thickening), and then 60 ° C. hot air was blown to dry to produce a reflective layer B1. Each layer constituting the reflective layer is to determine the abundance of the high refractive index material cutting surface to cut the optical reflection film samples by XPS surface analyzer (TiO ₂₎ and the low refractive index material (SiO ₂₎ Thus, it was confirmed that the film thickness of each of the above layers was secured.

<Preparation of Optical Reflective Film of Sample 107>
The reflective layer B1 was prepared in the same manner as the sample 106, and the ultraviolet absorber was changed in the same manner as in the preparation of the sample 102 except that the thickness of the adhesive layer (first ultraviolet absorbing layer) was 10 μm. An optical reflective film of Sample 107, which was composed of a base material (second ultraviolet absorbing layer) containing, a reflective layer B1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber, was prepared.

<Preparation of Optical Reflective Film of Sample 108>
Except for the thickness of the adhesive layer (first ultraviolet absorbing layer) being 20 μm, the substrate containing the ultraviolet absorber (second ultraviolet absorbing layer) and the reflective layer are produced in the same manner as in the preparation of the sample 106 described above. An optical reflective film of Sample 108 composed of an adhesive layer (first ultraviolet absorbing layer) containing B1 and an ultraviolet absorber was produced.

<Preparation of Optical Reflective Film of Sample 109>
Except for the thickness of the adhesive layer (first ultraviolet absorbing layer) being 20 μm, the substrate containing the ultraviolet absorber (second ultraviolet absorbing layer) and the reflective layer are produced in the same manner as in the preparation of the sample 107 described above. An optical reflective film of Sample 109 made of an adhesive layer (first ultraviolet absorbing layer) containing B1 and an ultraviolet absorber was produced.

<Preparation of Optical Reflective Film of Sample 110>
Except for the thickness of the adhesive layer (first ultraviolet absorbing layer) being 30 μm, the base material containing the ultraviolet absorber (second ultraviolet absorbing layer) and the reflective layer are produced in the same manner as in the preparation of the sample 107 described above. An optical reflective film of Sample 110 made of an adhesive layer (first ultraviolet absorbing layer) containing B1 and an ultraviolet absorber was produced.

<Preparation of Optical Reflective Film of Sample 111>
Except for the thickness of the substrate (second ultraviolet absorbing layer) being 50 μm, the substrate containing the ultraviolet absorber (second ultraviolet absorbing layer) and the reflective layer are the same as in the preparation of the sample 109 described above. An optical reflective film of Sample 111 made of an adhesive layer (first ultraviolet absorbing layer) containing B1 and an ultraviolet absorber was produced.

<Preparation of Optical Reflective Film of Sample 112>
The base material (second ultraviolet absorbing layer) containing the ultraviolet absorber, the reflective layer B2, and the ultraviolet absorbing material are the same as those of the sample 111 described above except that the reflecting layer B2 is manufactured by the following method. An optical reflective film of Sample 112 composed of an adhesive layer (first ultraviolet absorbing layer) containing an agent was prepared.

[Reflection layer B2]
Using a slide hopper coating apparatus capable of 19-layer multilayer coating, the high refractive index layer coating solution and the low refractive index layer coating solution prepared in Sample 101 described above, and the low Tg resin-containing low refractive index prepared in Sample 105 described above The rate layer coating solution [1] was adjusted to 40 ° C., respectively. Then, on the other surface (surface) of the base material heated to 40 ° C., the lowermost layer is a low Tg resin-containing low refractive index layer, and a high refractive index layer and a low refractive index layer are alternately formed thereon. A total of 19 simultaneous multilayer coatings were carried out, with the outermost layer being a low refractive index layer. In the simultaneous multilayer coating, the low refractive index layer (including the low refractive index layer containing low Tg resin) is 150 nm after drying, and the high refractive index layer is 130 nm after drying. It was. Thereafter, the reflective layer B2 was produced in the same manner as the reflective layer B1 of the sample 106.

<Preparation of Optical Reflective Film of Sample 113>
As an ultraviolet absorber used for the substrate (second ultraviolet absorbing layer), ADEKA STAB LA-29 (2- (2H-Benzotriazol-2-yl) -4- (manufactured by Adeka), which is a benzotriazole-based ultraviolet absorber. Except that 1,1,3,3-tetramethylbutyl) phen) was used in the same amount, a base material containing a UV absorber (second UV absorbing layer) in the same manner as in the preparation of Sample 111 described above, An optical reflective film of Sample 113 composed of the reflective layer B1 and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber was produced.

<Preparation of Optical Reflective Film of Sample 114>
The UV absorber is the same as that of the above-described sample 111 except that ASF Tinuvin 477, which is a triazine UV absorber, is used as the UV absorber used for the substrate (second UV absorbing layer). An optical reflective film of Sample 114 was prepared, which was composed of a base material (second ultraviolet absorbing layer) containing, a reflective layer B1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber.

<Preparation of Optical Reflective Film of Sample 115>
Preparation of sample 111 as described above, except that SEESORB100 (2,4-dihydroxybenzophenone) made by Cypro Kasei, which is a benzophenone-based UV absorber, was used as the UV absorber used for the base material (second UV absorbing layer). In the same manner, the optical reflective film of sample 115 comprising a base material (second ultraviolet absorbing layer) containing an ultraviolet absorber, a reflective layer B1, and an adhesive layer (first ultraviolet absorbing layer) containing an ultraviolet absorber. Was made.

<Preparation of Optical Reflective Film of Sample 116>
Except that the reflective layer B2 was produced, the base material containing the ultraviolet absorber (second ultraviolet absorbent layer), the reflective layer B2, and the adhesive layer containing the ultraviolet absorber were prepared in the same manner as in the production of the sample 114 described above. An optical reflective film of Sample 116 made of (first ultraviolet absorbing layer) was produced.

<Preparation of Optical Reflective Film of Sample 117>
Except that the reflective layer B3 was produced by the following method, a base material (second ultraviolet absorbent layer) containing the ultraviolet absorbent, the reflective layer B2, and the ultraviolet absorbent was produced in the same manner as in the production of the sample 114 described above. An optical reflective film of Sample 117 made of an adhesive layer (first ultraviolet absorption layer) containing

[Reflection layer B3]
(Preparation of low Tg resin-containing low refractive index layer coating solution [2])
A coating solution for a low refractive index layer containing a low Tg resin was prepared as follows.
13 parts by mass of an acidic colloidal silica 10% by mass aqueous solution (Snowtex OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) was heated to 40 ° C., and 3 parts by mass of boric acid 3% by mass aqueous solution was added. Furthermore, as a water-soluble resin, 35 parts by mass of a 6% by weight aqueous solution of polyvinyl alcohol (PVA-224, average polymerization degree: 2400, saponification degree: 87 mol%, manufactured by Kuraray Co., Ltd.) and a 6% by weight aqueous solution of water-dispersed urethane resin ( 3 parts by mass of ETERNACOLL UW-1005E, Tg = -30 ° C., manufactured by Ube Industries, Ltd.) and 1 part by mass of a 5% by weight aqueous solution of surfactant (Softazoline LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) Were added in this order to prepare a low Tg resin-containing low refractive index layer coating solution [2].

(Preparation of reflective layer B3)
Using a slide hopper coating apparatus capable of 19-layer multilayer coating, the high refractive index layer coating solution and the low refractive index layer coating solution prepared in the above-mentioned sample 101, and the low refractive index containing low Tg resin adjusted by the above method The layer coating solution [2] was adjusted to 40 ° C., respectively. Then, on the other surface (surface) of the base material heated to 40 ° C., the lowermost layer is a low Tg resin-containing low refractive index layer, and a high refractive index layer and a low refractive index layer are alternately formed thereon. A total of 19 simultaneous multilayer coatings were carried out, with the outermost layer being a low refractive index layer. In the simultaneous multilayer coating, the low refractive index layer (including the low refractive index layer containing low Tg resin) is 150 nm after drying, and the high refractive index layer is 130 nm after drying. It was. Thereafter, the reflective layer B3 was produced in the same manner as the reflective layer B1 of the sample 106.

<Preparation of Sample 118 (Reference)>
As a reference sample, an adhesive layer (first ultraviolet ray) containing a polyethylene terephthalate film (Toyobo A4300: double-sided easy-adhesive layer, width 160 mm, thickness 50 μm) and containing an ultraviolet absorber in the same manner as the sample 101 described above. Only an absorption layer) was produced, and a sample 118 composed of a base material (not including an ultraviolet absorber) and an adhesive layer (first ultraviolet absorption layer) was produced.

<Preparation of Optical Reflective Film of Sample 119>
On a polyethylene terephthalate film (Toyobo A4300: double-sided easy-adhesion layer, width 160 mm, thickness 50 μm), in the same manner as the sample 101 described above, the reflective layer A1 and an adhesive layer containing an ultraviolet absorber (first An ultraviolet absorbing layer) was prepared, and a sample 119 including a base material (not including an ultraviolet absorber), a reflective layer A1, and an adhesive layer (first ultraviolet absorbing layer) was prepared.

<Preparation of optical reflection film of sample 120>
Except for the thickness of the pressure-sensitive adhesive layer (first ultraviolet absorbing layer) being 10 μm, the substrate (not including the ultraviolet absorber), the reflective layer A1, and the pressure-sensitive adhesive layer (including the ultraviolet absorbing agent) are the same as the above-described sample 119. A sample 120 made of a first ultraviolet absorbing layer was prepared.

<Preparation of Optical Reflective Film of Sample 121>
Except that the reflective layer A2 was produced, a sample 121 composed of a base material (not including an ultraviolet absorber), the reflective layer A2, and an adhesive layer (first ultraviolet absorber layer) was produced in the same manner as the sample 120 described above. Was made.

<Preparation of Optical Reflective Film of Sample 122>
Except that the reflective layer A3 was prepared, a sample 122 composed of a base material (not including an ultraviolet absorber), the reflective layer A3, and an adhesive layer (first ultraviolet absorber layer) was produced in the same manner as the sample 120 described above. Was made.

<Preparation of Optical Reflective Film of Sample 123>
Except that the reflective layer B1 was produced, a sample 123 composed of a base material (not including an ultraviolet absorber), the reflective layer B1, and an adhesive layer (first ultraviolet absorber layer) was produced in the same manner as the sample 119 described above. Was made.

<Evaluation>
[Measurement of infrared reflectance and visible light transmittance]
Separator SP-PET (peeling film) was peeled off from each sample of the produced optical reflecting film, and the optical reflecting film was attached to glass via an adhesive layer. Then, using a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4100), the infrared reflectance (1000 to 1200 nm) of each optical reflective film was measured, and the average reflectance was calculated. Further, the ultraviolet transmittance (300 to 380 nm) was also measured.

[Initial peel test]
It implemented with the form of only a reflective layer and a base material. After performing the test once according to the cross-cut method specified in JIS 5600K-5-6 with the reflective layer surface as the upper surface, the tape peeling test is performed four times at the same location, and the tape peeling is performed five times in total. After that, the test results were classified according to JIS 5600K-5-6.

[Weather resistance peel test]
It implemented with the form of only a reflective layer and a base material. After carrying out the following weather resistance test (however, the base material is closer to the light source than the reflective layer, the test piece holder is an open type), and the reflective layer surface is used as the upper surface as specified in JIS 5600K-5-6. After performing a tape peel test once according to a certain cross-cut method, and further performing a tape peel test at the same location four times, and after performing a total of five tape peels, according to JIS 5600K-5-6 The test results were classified.

[Weather resistance peel test]
Implemented on samples with an adhesive layer and UV absorbing layer. After carrying out the following weather resistance test (however, the test piece holder uses an open mold), a 180 degree peel test was carried out, and the distance until breaking or peeling was measured.

(Weather resistance test method)
Separator SP-PET (peeling film) was peeled off from each sample of the produced optical reflecting film, and the optical reflecting film was attached to 6 cm × 12 cm glass via an adhesive layer. Then, using a xenon weather meter (Suga Tester SX-75), the glass side was placed on the light incident side, and the test was carried out for 5000 hours in accordance with JIS K 7350-2.

Table 1 shows each configuration and each evaluation result of the optical reflection films of Samples 101 to 123.

As shown in Table 1, the samples 118 to 123 that do not have the second UV absorbing layer have the same initial peel test as the samples 101 to 117 that have the second UV absorbing layer. Nevertheless, the results of the weathering peel test and the weathering peel test are getting worse. From this result, it can be seen that by having not only the first ultraviolet absorbing layer (light incident side) but also the second ultraviolet absorbing layer (back side), breakage of the optical reflective film can be suppressed even after long-term use.

Further, when samples 101 to 117 were compared, as the tendency of the thickness of the second ultraviolet absorbing layer (back surface side) to increase, a better result was obtained in the weather resistance peel test. This is considered to be due to the fact that the amount of the ultraviolet absorbent contained increases as the thickness of the second ultraviolet absorbing layer (back side) increases.

Moreover, in the sample containing the low Tg resin in the lowermost layer of the reflective layer, particularly good results were obtained in the weather resistance peel test as well as the initial peel test. This is because by forming a layer containing a low Tg resin in the lowermost layer of the reflective layer, the adhesion and adhesive strength between the substrate and the reflective layer are improved, and by having a second ultraviolet absorbing layer This is probably because the deterioration of the low Tg resin was suppressed and the initial high adhesion and adhesive strength were maintained.

Accordingly, the first ultraviolet absorbing layer is provided on the surface of one surface (for example, the light incident side) of the optical reflecting film, and the second ultraviolet absorbing layer (for example, on the back surface side) of the optical reflecting film is provided. By having the back surface side), it is possible to suppress degradation of the base material and the reflective layer due to ultraviolet rays, and it is possible to suppress breakage of the optical reflective film.

The present invention is not limited to the configuration described in the above embodiment, and various modifications and changes can be made without departing from the configuration of the present invention.

10, 10A, 20, 20A ... optical reflective film, 11, 11A ... base material, 12, 23 ... reflective layer, 13, 25 ... first ultraviolet absorbing layer, 14, 26 ... -2nd ultraviolet absorption layer, 21, 21A ... 1st base material, 22 ... adhesion layer, 24 ... 2nd base material

Claims

A substrate;
A reflective layer provided on the substrate;
A first ultraviolet absorbing layer provided on the reflective layer,
An optical reflective film comprising an ultraviolet absorber in at least one of the base material and a layer provided on a surface of the base material opposite to the surface on which the reflective layer is formed.
The optical reflective film according to claim 1, wherein the average spectral reflectance at a wavelength of 1000 to 1200 nm is 30% or more and less than 90%, and the maximum spectral transmittance at a wavelength of 300 to 380 nm is 50% or less.
The optical reflective film according to claim 1, wherein the ultraviolet absorber contains at least one selected from a benzotriazole compound, a triazine compound, and a benzophenone compound.
The optical reflective film according to claim 1, wherein the layer provided on the most base side of the reflective layer contains a polymer compound having a glass transition temperature of 0 ° C or lower.
The optical reflective film according to claim 4, wherein the polymer compound has a urethane bond.
A first substrate;
An adhesive layer provided on the first substrate;
A reflective layer provided on the adhesive layer;
A second substrate provided on the reflective layer;
A first ultraviolet absorbing layer provided on the second substrate,
An optical reflective film comprising an ultraviolet absorber in at least one of the first base material and a layer provided on the surface of the first base material opposite to the surface on which the reflective layer is formed.