WO2017010280A1

WO2017010280A1 - Heat ray shielding film

Info

Publication number: WO2017010280A1
Application number: PCT/JP2016/069130
Authority: WO
Inventors: 光範後藤; 安藤　達哉; 本田　誠
Original assignee: コニカミノルタ株式会社
Priority date: 2015-07-13
Filing date: 2016-06-28
Publication date: 2017-01-19

Abstract

Provided is a heat ray shielding film which is able to have improved weather resistance. This heat ray shielding film is configured to comprise a base, a heat ray shielding layer and an ultraviolet absorbing layer, and is also configured such that: the ultraviolet absorbing layer is arranged on the outer side of the heat ray shielding layer; the maximum transmittance of the ultraviolet absorbing layer at a wavelength of 350-400 nm is 40% or less; and the minimum transmittance of the heat ray shielding film at a wavelength of 420-780 nm is 40% or more.

Description

Heat ray shielding film

The present invention relates to a heat ray shielding film provided with a heat ray shielding layer that absorbs or reflects heat rays such as infrared rays.

In recent years, many films for pasting windows that are bonded to the window glass surfaces of buildings and vehicles have been used. One of them is a heat ray shielding film for blocking infrared rays, which has the function of suppressing the intrusion of infrared rays into the building and preventing the indoor temperature from rising excessively, reducing the amount of cooling used, Contributes to energy saving.

As a heat ray shielding film that reflects infrared rays, a configuration having an infrared reflection laminate formed by alternately laminating layers having different refractive indexes has been proposed (for example, see Patent Document 1). This infrared reflective laminate is composed of a high refractive index layer and a low refractive index layer in which metal oxide fine particles such as titanium oxide are dispersed in a water-soluble resin.

It has also been proposed to use metal oxide particles such as tungsten oxide and composite tungsten oxide for the heat ray shielding film in order to shield infrared rays. However, tungsten oxide and composite tungsten oxide have a problem in weather resistance such that the infrared shielding properties deteriorate with time. In order to solve this problem, it has been proposed to use an ultraviolet absorbing material such as a benzotriazole compound, a triazine compound, and an indole compound for the heat ray shielding film (see, for example, Patent Document 2).

JP 2012-131130 A JP, 2014-210698, A

However, even in the configuration using the above-described ultraviolet absorbing material, the heat ray shielding film is damaged such as cracks or peeling of the base material, discoloration, etc. due to exposure to sunlight for a long time. Thus, the weather resistance of the heat ray shielding film cannot be sufficiently improved only by including the ultraviolet ray absorbing material in the heat ray shielding film.

In order to solve the above-described problems, the present invention provides a heat ray shielding film capable of improving the weather resistance.

The heat ray shielding film of the present invention has a base material, a heat ray shielding layer, and an ultraviolet ray absorbing layer, the ultraviolet ray absorbing layer is provided outside the heat ray shielding layer, and the ultraviolet ray absorbing layer has a maximum transmittance at a wavelength of 350 to 400 nm. Is 40% or less, and the minimum transmittance of the heat ray shielding film at a wavelength of 420 to 780 nm is 40% or more.

According to the present invention, a heat ray shielding film capable of improving weather resistance can be provided.

It is a figure which shows the structure of the heat ray shielding film (optical reflection film) of 1st Embodiment. It is a figure which shows schematic structure of the heat ray shielding film of 2nd Embodiment. It is a figure which shows schematic structure of the heat ray shielding film of 3rd 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 the heat ray shielding film (optical reflection film) (first embodiment)
2. Embodiment of heat ray shielding film (second embodiment)
3. Embodiment of heat ray shielding film (third embodiment)

<1. Heat ray shielding film (optical reflection film) (first embodiment)>
Hereinafter, specific embodiments of the heat ray shielding film of the present invention will be described.
The heat ray shielding film has a base material, a heat ray shielding layer, and an ultraviolet ray absorbing layer, and the heat ray shielding film is provided with an ultraviolet ray absorbing layer outside the heat ray shielding layer. The heat ray shielding film has a maximum transmittance at a wavelength of 350 to 400 nm of the ultraviolet absorbing layer of 40% or less, and a minimum transmittance of the heat ray shielding film at a wavelength of 420 to 780 nm is 40% or more.

The outer side of the dielectric multilayer film on which the ultraviolet absorbing layer is provided is the outside of both main surfaces of the heat ray shielding layer in the stacking direction of the base material and the heat ray shielding layer. Specifically, with respect to the light incident on the heat ray shielding film, the light incident surface side of the heat ray shielding layer is closer to the light incident surface side and the opposite side of the light incident surface (light emission surface side, back surface side). The light emission surface side is shown from the main surface.

In the heat ray shielding film, the heat ray shielding layer is preferably provided on the substrate. In particular, the heat ray shielding layer is preferably formed directly on the substrate. Thereby, the laminated structure (laminated body) which consists of a base material and a heat ray shielding layer is formed. However, as long as it has a laminated structure including a base material and a heat ray shielding layer, it may be a laminate having a structure in which another layer is formed between the base material and the heat ray shielding layer. And in the main surface of the laminated body which consists of a base material and a heat ray shielding layer, it is preferable that an ultraviolet absorption layer is provided in at least one surface. That is, it is preferable that an ultraviolet absorbing layer is provided outside the substrate and the heat ray shielding layer. Specifically, it is preferable that the ultraviolet absorbing layer is provided on the side on which light including a wavelength intended for shielding by the heat ray shielding layer is incident, rather than the base material and the heat ray shielding layer.

The maximum transmittance of the heat ray shielding film at a wavelength of 350 to 400 nm is preferably 3% or less. The minimum transmittance at a wavelength of 450 to 600 nm of the heat ray shielding film is preferably 70% or more. The difference in transmittance at a wavelength of 450 to 600 nm of the heat ray shielding film is preferably 20% or less. In the heat ray shielding film, the transmittance at each wavelength is a value measured by the method described in JIS R3106-1998. Specifically, it can be evaluated by the transmittance in a wavelength range of 200 to 2000 nm of a spectrophotometer U-4000 type (using an integrating sphere, manufactured by Hitachi, Ltd.).

Since the heat ray shielding film includes an ultraviolet ray absorbing layer and has the above optical characteristics, the ultraviolet ray irradiation to the base material and the heat ray shielding layer is suppressed, and even in long-term exposure to sunlight or the like, Discoloration can be suppressed. Or damage, such as a crack of a heat ray shielding film and peeling of a base material, can be suppressed. Therefore, the weather resistance of the heat ray shielding film can be improved. Furthermore, since the transmittance at a wavelength of 420 to 780 nm which is a visible light region is high, transparency as a heat ray shielding film can be ensured.

The heat ray shielding layer is preferably a dielectric multilayer film in which a high refractive index layer containing a water-soluble polymer and titanium oxide and a low refractive index layer containing a water-soluble polymer are alternately laminated. Alternatively, the heat ray shielding layer preferably contains one or more infrared absorbing materials selected from tungsten oxide and composite tungsten oxide. When the heat ray shielding layer has these configurations, the infrared ray shielding ability can be enhanced while maintaining the transparency of the heat ray shielding film.

Since the heat ray shielding film has an ultraviolet absorbing layer, it is possible to reduce ultraviolet irradiation to the titanium oxide contained in the dielectric multilayer film. For this reason, it suppresses the discoloration by the self-reduction at the time of light irradiation of titanium oxide, and suppresses the discoloration of the dielectric multilayer film, thereby suppressing the deterioration of the optical properties such as coloring of the heat ray shielding film and the light transmittance. be able to. In particular, discoloration of rutile titanium dioxide having an absorption region on the long wavelength side of ultraviolet light can be suppressed by the low transmittance at a wavelength of 350 to 400 nm, which is ultraviolet light on the long wavelength side close to visible light.

Further, since the minimum transmittance at a wavelength of 450 to 600 nm is 70% or more, high transparency can be imparted to the heat ray shielding film, which is preferable when applied to a window glass, a car windshield, and the like. Furthermore, since the transmittance difference between wavelengths 450 to 600 nm is 20% or less, the wavelength deviation (wavelength dependence) of transmitted light is reduced, and further improvement in transparency, and in dark and bright places. A difference in visibility can be suppressed.

The ultraviolet ray absorbing layer of the heat ray shielding film contains an ultraviolet ray absorbing material. The ultraviolet absorbing material contained in the ultraviolet absorbing layer preferably contains one or more selected from an indole compound, an azomethine compound, a coumarin compound, and a merocyanine compound. Hereinafter, the indole compound, the azomethine compound, the coumarin compound, and the merocyanine compound are referred to as an ultraviolet absorbing material group A.
These ultraviolet absorbing materials have high absorption ability at a wavelength of 350 to 400 nm. For this reason, it is effective for suppression of discoloration of titanium oxide and improvement of weather resistance.

Further, the ultraviolet ray absorbing layer of the heat ray shielding film includes at least one ultraviolet ray absorbing material selected from the above ultraviolet ray absorbing material group A, and at least one selected from a benzotriazole compound, a triazine compound, and a benzophenone compound. It is preferable that an ultraviolet absorbing material is included. Hereinafter, the benzotriazole compound, the triazine compound, and the benzophenone compound are referred to as an ultraviolet absorbing material group B.
These ultraviolet absorbing materials have a higher ability to absorb ultraviolet rays on the shorter wavelength side than the compounds of the ultraviolet absorbing material group A. For this reason, by using it with the material of the above-mentioned ultraviolet absorbing material group A, it is possible to absorb a wider range of ultraviolet rays and improve the weather resistance of the heat ray shielding film.

The ultraviolet absorbing layer preferably contains 0.05 to 15% by mass of an ultraviolet absorbing material. When the ultraviolet absorbing layer has only the material of the ultraviolet absorbing material group A as the ultraviolet absorbing material, the ultraviolet absorbing layer preferably contains 0.05 to 15% by mass of the material of the ultraviolet absorbing material group A. Further, when the ultraviolet absorbing layer has the material of the ultraviolet absorbing material group A and the material of the ultraviolet absorbing material group B, the total of the material of the ultraviolet absorbing material group A and the material of the ultraviolet absorbing material group B is 0. .05 to 15% by mass is preferable. Further, when ultraviolet absorbing materials other than the ultraviolet absorbing material group A and the ultraviolet absorbing material group B are included, the total amount of these ultraviolet absorbing materials is preferably 0.05 to 15% by mass.

The ultraviolet absorption layer only needs to be provided on one outer side of the heat ray shielding layer. Preferably, it is provided outside the light incident side. By providing the ultraviolet absorbing layer on the light incident side, the ultraviolet rays incident on the heat ray shielding layer can be reduced.
It is also possible to adopt a configuration in which the ultraviolet absorbing layer is provided on both sides of the heat ray shielding layer. Reflected light or the like may enter the heat ray shielding film from the back side. Even in such a case, the ultraviolet ray incident on the heat ray shielding layer from the back surface side can be reduced by providing the ultraviolet ray absorbing layer on the back surface side of the heat ray shielding layer.

In addition, in the heat ray shielding film, the ultraviolet absorbing layer can include an adhesive. In this case, a heat ray shielding film capable of causing the ultraviolet absorbing layer to function as an adhesive layer is configured. Further, for example, by including an ultraviolet absorbing material in the substrate, the substrate can function as an ultraviolet absorbing layer. By adopting a configuration in which other functions are added to such an ultraviolet absorbing layer, the layer structure of the heat ray shielding film can be simplified.

[Configuration of heat ray shielding film]
FIG. 1 shows a schematic configuration of the heat ray shielding film. A heat ray shielding film 10 shown in FIG. 1 includes a base material 11, a dielectric multilayer film 12 that is a heat ray shielding layer, and an ultraviolet absorption layer 13. The dielectric multilayer film 12 which is a heat ray shielding layer has a configuration in which high refractive index layers and low refractive index layers are alternately stacked. The ultraviolet absorbing layer 13 is provided on the main surface opposite to the base material 11 with respect to the dielectric multilayer film 12 provided on the base material 11. In the heat ray shielding film 10, the ultraviolet absorption layer 13 side is a light incident (drawing arrow) surface. For this reason, the ultraviolet absorbing layer 13 is disposed outside the light incident surface side of the dielectric multilayer film 12.

[Dielectric multilayer film]
The dielectric multilayer film 12 which is a heat ray shielding layer has a configuration in which low refractive index layers and high refractive index layers are alternately stacked. The dielectric multilayer film 12 has a low-refractive index layer and a high-refractive index layer on the substrate 11 when a two-layered laminate in which a low-refractive index layer and a high-refractive index layer are stacked one by one is used as one unit. And at least one unit.

In the dielectric multilayer film 12, when comparing the refractive index difference between two adjacent layers, the higher refractive index layer and the lower refractive index layer are the higher refractive index layer and the lower refractive index layer. The layer is a low refractive index layer. Therefore, the high refractive index layer and the low refractive index layer in the dielectric multilayer film 12 are determined by comparing the refractive indexes of two adjacent layers in each layer constituting the dielectric multilayer film 12.

The thickness per layer of the high refractive index layer and the low refractive index layer (thickness after drying) is preferably 20 to 1000 nm. Further, it is preferably 50 to 500 nm, more preferably 100 to 300 nm, and particularly preferably 100 to 200 nm.

The number (total number) of the high refractive index layer and the low refractive index layer constituting the dielectric multilayer film 12 is not particularly limited, but is preferably 6 to 2000, more preferably 10 to 1500, and still more preferably. Is from 10 to 1000. If the number of layers exceeds 2000, haze is likely to occur, and if it is less than 6, the desired reflectance may not be achieved.

In the dielectric multilayer film 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, in the stacking direction of the dielectric multilayer film 12, the concentration profiles of the components constituting the high refractive index layer and the low refractive index layer are measured, and the high refractive index layer or the low refractive index layer is obtained depending on the composition. be able to. The concentration profile can measure the atomic composition ratio of the surface exposed by etching using an XPS (X-ray-photoelectron-spectroscopy) surface analyzer while etching in the depth direction from the surface using a sputtering method.

The reflectance of the dielectric multilayer film 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 dielectric multilayer film 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 dielectric multilayer film 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.

The refractive index of the high refractive index layer and the low refractive index layer is determined according to the following method. Specifically, a sample in which each layer is formed as a single layer on a substrate is prepared, the sample is cut into 10 cm × 10 cm, and then the refractive index is obtained according to the following method.

First, after roughening the surface opposite to the measurement surface (back surface) of the sample, light absorption processing is performed with a black spray to prevent reflection of light on the back surface. Then, using a U-4000 type (manufactured by Hitachi, Ltd.) as a spectrophotometer, the reflectance in the visible light region (400 nm to 700 nm) is measured at 25 points under the condition of regular reflection at 5 degrees, and an average value is obtained. The average refractive index is obtained from the measurement result.

The reflection at the interface between adjacent layers depends on the refractive index ratio of the adjacent layers. For this reason, the greater the refractive index ratio between adjacent layers, the higher the reflectivity. 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 represented by [n · d = λ / 4], the reflection at this specific wavelength is suppressed. It can be controlled to be strengthened by the phase difference. As a result, the reflectance of a specific wavelength can be increased. 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.

Thus, in the dielectric multilayer film 12, the reflection of each wavelength can be controlled by utilizing the optical path difference. That is, the reflection of 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.

The heat ray shielding film 10 is configured to increase the transmittance in a specific wavelength range or to increase the reflectivity in a specific wavelength range by arbitrarily adjusting the wavelength range that improves the reflectivity in the dielectric multilayer film 12. It can be. Thus, the optical characteristics of the heat ray shielding film 10 can be arbitrarily set by the configuration of the dielectric multilayer film 12.

In the heat ray shielding film 10, by adjusting the configuration of the dielectric multilayer film 12, the transmittance at 550 nm in the visible light region shown in JIS R3106: 1998 is preferably 50% or more, and 70% or more. More preferably, it is more preferably 75% or more. Further, the transmittance at 1200 nm is preferably 35% or less, more preferably 25% or less, and further preferably 20% or less. In addition, it is preferable not to provide a region with a reflectance exceeding 50% in a region with a wavelength of 900 to 1400 nm.

In the heat ray shielding film 10, the minimum transmittance at a wavelength of 420 to 780 nm is set to 40% or more by adjusting the configuration of the dielectric multilayer film 12. By increasing the transmittance at a wavelength of 420 to 780 nm, the transparency and transparency in the visible light region can be enhanced.

The difference in refractive index between the high refractive index layer and the low refractive index layer and the number of layers constituting the dielectric multilayer film 12 can be calculated using commercially available optical design software. For example, in order to obtain an infrared reflectivity (infrared shielding rate) of 90% or more, if the difference in refractive index is smaller than 0.1, a laminate exceeding 100 layers is required, which not only reduces productivity. , Scattering at the laminated interface increases and transparency decreases. For this reason, the difference in refractive index between the adjacent high refractive index layer and low refractive index layer 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 the reflectance 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.

(High refractive index layer / Low refractive index layer)
The high refractive index layer includes metal oxide fine particles and a water-soluble polymer. Furthermore, the high refractive index layer 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. The high refractive index layer preferably has the largest proportion of titanium oxide as metal oxide fine particles. More preferably, it is preferable to contain 50% by mass or more of titanium oxide as the metal oxide fine particles. Further, the metal oxide fine particles preferably contain 70% by mass or more of titanium oxide, and more preferably contain 80% by mass or more of titanium oxide.

The low refractive index layer includes a water-soluble polymer. The low refractive index layer may be configured to include inorganic oxide fine particles and metal oxide fine particles together with the water-soluble polymer. When the high refractive index layer and the low refractive index layer contain fine oxide particles, the refractive index can be easily adjusted. For this reason, by including oxide fine particles, the number of stacked layers can be reduced, and a thin film can be obtained. By reducing the number of layers, productivity can be improved and a decrease in transparency due to scattering at the lamination interface can be suppressed.

(Water-soluble polymer)
The water-soluble polymer contained in the high refractive index layer and the low refractive index layer functions as a binder in the layer. When the high refractive index layer and the low refractive index layer contain a water-soluble polymer, environmental problems due to organic solvents can be solved. Moreover, a softness | flexibility is obtained for a coating film by using water-soluble polymer as a binder. The water-soluble polymers contained in the high refractive index layer and the low refractive index layer may be the same or different. Preferably, different materials are used for the high refractive index layer and the low refractive index layer. The water-soluble polymer is a polymer compound that dissolves 1.0% by mass or more at 40 ° C. in an aqueous medium.

Since the high refractive index layer and the low refractive index layer contain a water-soluble polymer, a wet film formation method such as a coating method or a spin coating method can be applied to the formation of these layers. Since these film-forming methods are simple and do not ask | require the heat resistance of a base material, especially in the heat ray shielding film 10 using the base material 11, it is effective. In addition, a mass production method such as a roll-to-roll method can be adopted, which is advantageous in terms of cost and process. Moreover, since the film | membrane containing a water-soluble polymer has high flexibility, even if it winds up at the time of production and conveyance, it is hard to generate | occur | produce a defect and is excellent in handling property.

The water-soluble polymer contained in the high refractive index layer and the low refractive index layer is not particularly limited. Examples of the water-soluble polymer contained in the high refractive index layer and the low refractive index layer include gelatin, thickening polysaccharides, polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylic Acrylic resins such as potassium acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer Styrene-acrylic acid resin such as styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α -methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene -Sodium styrene sulfonate copolymer, Styrene-2- Roxyethyl acrylate copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl Examples thereof include vinyl acetate copolymers such as naphthalene-maleic acid copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, and vinyl acetate-acrylic acid copolymer. Among these, it is preferable to include polyvinyl alcohol and polyvinyl alcohol derivatives, which are polyvinyl alcohols, from the viewpoints of coatability and film thickness uniformity (haze). A water-soluble polymer may be used independently and may be used in combination of 2 or more type. The water-soluble polymer may be a synthetic product or a commercially available product.

As the water-soluble polymer, for example, publicly known to be used for a high refractive index layer and a low refractive index layer described in International Publication No. 2012/128109, Japanese Unexamined Patent Application Publication No. 2013-121567, Japanese Unexamined Patent Application Publication No. 2013-148849, etc. These resins can be used in the same manner. Specifically, as polyvinyl alcohol resin, various modified polyvinyl alcohols can be used in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate.

The polyvinyl alcohol obtained by hydrolyzing the above-mentioned polyvinyl 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%.

Also, 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-based polymers. These polyvinyl alcohols may be used alone or in combination of two or more. Polyvinyl alcohol may be a synthetic product or a commercial product.

The cation-modified polyvinyl alcohol is, for example, polyvinyl 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. Examples include alcohol. This cation-modified polyvinyl alcohol is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

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

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

Examples of the ethylene-modified polyvinyl alcohol include those described in JP 2009-107324 A, JP 2003-248123 A, JP 2003-342322 A, and the like. Commercial products such as EXEVAL (trade name: manufactured by Kuraray Co., Ltd.) may also be used.

Examples of the vinyl alcohol-based polymer include EXEVAL (trade name: manufactured by Kuraray Co., Ltd.), Nichigo G polymer (trade name: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and polyvinyl acetal resin obtained by reacting polyvinyl alcohol with an aldehyde ( For example, “S REC” manufactured by Sekisui Chemical Co., Ltd., silanol-modified polyvinyl alcohol having a silanol group (for example, “R-1130” manufactured by Kuraray Co., Ltd.), modified polyvinyl alcohol-based resin having an acetoacetyl group in the molecule (for example, And “Gosefimer (registered trademark) Z / WR series” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

The mass average molecular weight of polyvinyl alcohol is preferably 60000-250,000. As the value of “mass average molecular weight”, a value measured by a static light scattering method, gel permeation chromatography (GPC), TOFMASS, or the like is adopted. When the mass average molecular weight of the water-soluble polymer is in the above range, the wet film forming method can be applied, and the productivity can be improved.

The content of the water-soluble polymer in the high refractive index layer and the low 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 in each layer. preferable. When the content of the water-soluble polymer is 5% by mass or more, in wet film formation, it is possible to prevent deterioration of 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, the content is suitable when the layer contains metal oxide fine particles, and the refractive index difference between the low refractive index layer and the high refractive index layer. Can be increased.

In addition, content of water-soluble polymer is calculated | required from the residual solid content of the evaporation-drying method. Specifically, the thermal barrier 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. It can be determined that it is alcohol.

(Metal oxide fine particles; high refractive index layer)
The high refractive index layer contains titanium oxide as metal oxide fine particles. As titanium oxide, it is preferable to use a titanium dioxide sol from the viewpoint of the stability of the metal oxide fine particle-containing composition. Further, among titanium dioxide, it is preferable to use a rutile type because the catalytic activity is low, the weather resistance of the high refractive index layer and the adjacent layer is high, and the refractive index is high.
The preferred primary particle diameter of the titanium dioxide fine particles is 4 nm to 50 nm, more preferably 4 nm to 30 nm.

The titanium oxide particles are preferably used by modifying the surface of the titanium oxide sol so that it can be dispersed in water or an organic solvent. Examples of the preparation method of the aqueous titanium oxide sol include, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, JP-A-63-3. Reference can be made to the description of Japanese Patent No. 17221.

The average particle diameter of titanium oxide used in the high refractive index layer is preferably 100 nm or less, and more preferably 50 nm or less. From the viewpoint of a low haze value and excellent visible light transmittance, the average particle size is more preferably 1 to 30 nm, and more preferably 1 to 20 nm. In addition, an average particle diameter is a volume average particle diameter calculated | required with the following method here.

The average particle diameter is determined by measuring the diameter 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.

Then, the particle size of 1000 arbitrary particles is measured, and there are n1, n2..., Ni, nk particles each having a particle size of d1, d2,. When the volume per particle in a group is vi, the average particle diameter mv is obtained as a volume average particle diameter represented by {Σ (vi · di)} / {Σ (vi)}.

Further, the titanium oxide contained in the high refractive index layer may be in the form of core-shell particles coated with a silicon-containing hydrated oxide. The core-shell particle has a structure in which the surface of the titanium oxide particle is coated with a shell made of a silicon-containing hydrated oxide on the titanium oxide serving as the core. By including the core-shell particles in the high refractive index layer, the interlayer mixing of the low refractive index layer and the high refractive index layer is suppressed by the interaction between the silicon-containing hydrated oxide of the shell layer and the water-soluble resin. . Here, the “coating” means a state in which a silicon-containing hydrated oxide is attached to at least a part of the surface of the titanium oxide particles. That is, the surface of the titanium oxide particles may be completely covered with the silicon-containing hydrated oxide, or a part of the surface of the titanium oxide particles may be covered with the silicon-containing hydrated oxide. From the viewpoint that the refractive index of the coated titanium oxide particles is controlled by the coating amount of the silicon-containing hydrated oxide, it is preferable that a part of the surface of the titanium oxide particles is coated with the silicon-containing hydrated oxide. . Hereinafter, such coated titanium oxide particles are also referred to as “silica-attached titanium dioxide sol”.

The titanium oxide of the titanium oxide particles coated with the silicon-containing hydrated oxide may be a rutile type or an anatase type, but a rutile type is more preferable. Since rutile type titanium oxide particles have lower photocatalytic activity than anatase type titanium oxide particles, the weather resistance of the high refractive index layer and the adjacent low refractive index layer is increased. Moreover, the refractive index of a layer tends to become high by using a rutile type titanium oxide particle.

The silicon-containing hydrated oxide may be any of a hydrate of an inorganic silicon compound, a hydrolyzate of an organosilicon compound, and a condensate of an organosilicon compound. The silicon-containing hydrated oxide covering titanium oxide preferably has a silanol group.

The coating amount of the silicon-containing hydrated oxide is 3 to 30% by mass, preferably 3 to 10% by mass, more preferably 3 to 8% by mass with respect to titanium oxide. When the coating amount is 30% by mass or less, it is easy to increase the refractive index of the high refractive index layer, and when the coating amount is 3% by mass or more, the coated particles can be stably formed.

As a method of coating titanium oxide particles with a silicon-containing hydrated oxide, a conventionally known method can be applied. For example, JP-A-10-158015, JP-A-2000-204301, JP-A-2007- The method described in Japanese Patent No. 246351 can be applied.

Generally, titanium oxide particles are often used in a state where surface treatment has been performed for the purpose of suppressing photocatalytic activity on the particle surface and improving dispersibility in a solvent or the like. For the surface treatment, it is preferable to use one or more selected from silica, alumina, aluminum hydroxide, zirconia and the like. More specifically, the surface is covered with a silica coating layer, the surface of the particle is negatively charged titanium oxide particles, or the aluminum oxide coating layer is formed, and the surface is positively charged at pH 8-10. Titanium oxide particles are known.

Further, the high refractive index layer may contain metal oxide fine particles other than the above titanium oxide. Metal oxide fine particles other than titanium oxide include 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.

Specifically, zirconium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, Strontium titanate, yttrium oxide, hafnium oxide, niobium oxide, tantalum oxide, barium oxide, indium oxide, europium oxide, lanthanum oxide, zircon, tin oxide, lead oxide, and complex oxides composed of these oxides Examples thereof include lithium niobate, potassium niobate, lithium tantalate, and aluminum / magnesium oxide (MgAl ₂ O ₄ ).

In addition, rare earth oxides can also be used as the metal oxide fine particles. Specifically, scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, oxidation Examples also include terbium, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, and lutetium oxide.

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

The metal oxide fine particles used for the high refractive index layer may be used singly or in combination of two or more.
The volume average particle size of the metal oxide fine particles used for the metal oxide fine particles used in the high refractive index layer is preferably 100 nm or less, and more preferably 50 nm or less. Further, the volume average particle size of the metal oxide fine particles is more preferably 1 to 30 nm, and further preferably 5 to 15 nm. If the volume average particle size is in the above range, it is preferable from the viewpoint of low haze and excellent visible light transmittance.

The content of the metal oxide fine particles in the high refractive index layer is 20 to 80% by mass with respect to 100% by mass of the solid content of the high refractive index layer as the total of metal oxides other than titanium oxide and titanium oxide. It is preferably 30 to 75% by mass, more preferably 40 to 70% by mass.

(Inorganic oxide fine particles / metal oxide fine particles; low refractive index layer)
The low refractive index layer may contain metal oxide fine particles such as titanium oxide and inorganic oxide fine particles contained in the high refractive index layer. As the inorganic oxide fine particles contained in the low refractive index layer, it is preferable to use silicon dioxide, and it is particularly preferable to use colloidal silica.

Colloidal silica is obtained by metathesis with an acid such as sodium silicate or by heat aging of a silica sol obtained by 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. 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.

The metal oxide particles and inorganic oxide 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 primary particles of silicon dioxide 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, and more preferably 3 to 20 nm. Is particularly preferable, and 4 to 10 nm is most preferable. Moreover, as an average particle diameter of secondary particle | grains, it is preferable from a viewpoint with few hazes and excellent visible light transmittance | permeability that it is 30 nm or less. The average particle size of the 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 refractive index layer with an electron microscope and measuring the particle size of 1000 arbitrary particles. It is obtained as a simple average value (number average). Here, the particle diameter of each particle is expressed as a diameter assuming a circle equal to the projected area.

The content of the metal oxide particles and inorganic oxide fine particles in the low refractive index layer is preferably 5 to 80% by mass with respect to the solid content of the low refractive index layer, from the viewpoint of refractive index. More preferably, it is 75 mass%.

[UV absorbing layer]
The heat ray shielding film 10 includes at least one ultraviolet absorbing layer 13 outside the dielectric multilayer film 12. As shown in FIG. 1, the ultraviolet absorbing layer 13 is preferably provided on the light incident side of the dielectric multilayer film 12 that is a heat ray shielding layer in the heat ray shielding film 10. In addition, unlike the configuration shown in FIG. 1, when the substrate 11 side is the light incident surface, the ultraviolet absorbing layer 13 may be provided on the substrate 11 side of the dielectric multilayer film 12. In this case, it is possible to cause the base material 11 to function as the ultraviolet light absorbing layer 13 by containing the ultraviolet light absorbing material described later in the base material 11.

The ultraviolet absorbing layer 13 includes an ultraviolet absorbing material. The ultraviolet absorbing material contained in the ultraviolet absorbing layer 13 preferably includes an ultraviolet absorbing material having an absorption spectrum peak with an absorbance of 0.5 or more at a wavelength of 380 to 400 nm. In the following description, having a peak of an absorption spectrum having an absorbance of 0.5 or more in a specific wavelength region is expressed as having an absorption region in that wavelength region.
By including the ultraviolet absorbing material having an absorption region at a wavelength of 380 to 400 nm, the maximum transmittance of the ultraviolet absorbing layer 13 at a wavelength of 350 to 400 nm can be made 40% or less.

Examples of the ultraviolet absorbing material having an absorption region at a wavelength of 380 to 400 nm include indole compounds, azomethine compounds, coumarin compounds, and merocyanine compounds. A group of these ultraviolet absorbing materials is referred to as an ultraviolet absorbing material group A. The ultraviolet absorbing layer 13 preferably contains one or more selected from the ultraviolet absorbing material group A.

The thickness of the ultraviolet absorbing layer 13 is preferably 1 μm to 30 μm. By setting the thickness to 1 μm or more, the film formability of the ultraviolet absorbing layer 13 is improved, and the ultraviolet absorbing ability required for the ultraviolet absorbing layer 13 can be easily imparted. 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.

Hereinafter, preferred forms of the indole compound, the azomethine compound, the coumarin compound, and the merocyanine compound of the ultraviolet absorbing material group A will be described.
(Indole compound)
The indole compound is a compound having an indole skeleton represented by the following (Chemical Formula 1).

The indole compound contained in the ultraviolet absorbing layer 13 is preferably a compound represented by the following (Chemical Formula 2).

In Chemical Formula 2, R is an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a butyl group, and a 2-ethylhexyl group. An example of the aralkyl group having 7 to 10 carbon atoms is a phenylmethyl group.

(Azomethine compound)
As the azomethine compound contained in the ultraviolet absorbing layer 13, a compound having an azomethine skeleton represented by the following (Chemical Formula 3) is preferable.

In (Chemical Formula 3), R ¹ and R ² are a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, a hydroxyl group, an amino group, a carboxyl group, and a heterocyclic compound, and R ′ is a halogen atom. An alkyl group, an aryl group, an alkoxy group, a hydroxyl group, an amino group, a carboxyl group, and a heterocyclic compound.

The azomethine compound contained in the ultraviolet absorbing layer 13 is preferably a compound having a structure represented by the following (Chemical Formula 4).

(Coumarin compound)
The coumarin compound contained in the ultraviolet absorbing layer 13 is a compound having a coumarin skeleton represented by the following (Compound 5).

Preferred examples of the coumarin compound contained in the ultraviolet absorbing layer 13 include 7-diethylamino-4-methyl-chromen-2-one, 7-diethylamino-4a, 8a-dihydro-chromen-2-one, and 7-diethylamino-3. -Thiophen-2-yl-chromen-2-one, 7-dimethylamino-2-oxo-2H-chloromen-3-carbonitrile, 3- (1H-benzimidazol-2-yl) -7-diethylamino-chromene- 2-one, 1,1,6,6,8-pentamethyl-2,3,5,6-tetrahydro-1H, 4H-11-oxa-3a-aza-benzo [de] anthraphen-10-one, etc. Can be mentioned.

(Merocyanine compound)
Preferable examples of the merocyanine compound contained in the ultraviolet absorbing layer 13 include 1,3-dimethyl-5- [2- (3-methyl-oxadolidin) -ethylidene] -pyrimidine-2,4,6-trione, 1 , 3-Dimethyl-5- [2- (1-methyl-pyrrolidin-2-ylidene) -ethylidene] -pyrimidine-2,4,6-trione, 1,3-dimethyl-5- [2- (3-methyl -Thiazolidin-2-ylidene) -ethylidene] -pyrimidine-2,4,6-trione, 3-ethyl-5- [2- (1-methyl-pyrrolidin-2-ylidene) -ethylidene] -2-thioxo-oxazolidin -4-one, 3-ethyl-5- [2- (3-methyl-thiazolidin-2-ylidene) -ethylidene] -2-thioxo-oxazolidin-4-one, 1,3 Dimethyl-5- [2- (1-methyl-pyrrolidin-2-ylidene) -ethylidene] -2-thioxo-imidazolin-4-one, [5- [2- (3-methyl-thiazolidin-2-ylidene)- Ethylidene] -4-oxo-2-thioxo-thiazolidin-3-yl] -acetyl acid, 3-ethyl-5- [2- (3-methyl-thiazolidin-2-ylidin) -ethylidene] -2-thioxo-thiazolidin -4-one, [5- [1-methyl-2- (3-methyl-thiazolidin-2-ylidene) -ethylidene)]-4-oxo-2-thioxo-thiazolidin-3-yl] -acetyl acid and the like Can be mentioned.

The ultraviolet absorbing layer 13 preferably contains an ultraviolet absorbing material having an absorption region on the shorter wavelength side than this range, in addition to the above-described ultraviolet absorbing material having an absorption region at a wavelength of 380 to 400 nm. As the ultraviolet absorbing material having an absorption region on the shorter wavelength side than the wavelength of 380 to 400 nm, for example, an ultraviolet absorbing material having an absorption region at a wavelength of 300 to 350 nm is preferably used. Examples of the ultraviolet absorbing material having an absorption region at a wavelength of 300 to 350 nm include benzotriazole compounds, triazine compounds, and benzophenone compounds. A group of these ultraviolet absorbing materials is referred to as an ultraviolet absorbing material group B. The ultraviolet absorbing layer 13 preferably includes one or more ultraviolet absorbing materials selected from the ultraviolet absorbing material group B together with one or more ultraviolet absorbing materials selected from the ultraviolet absorbing material group A. As each compound of the ultraviolet absorbing material group B, a known material used as an ultraviolet absorber can be used.

The ultraviolet absorbing layer 13 preferably contains 0.05 to 15% by mass of an ultraviolet absorbing material. Further, it is preferable that 1 to 10% by mass of an ultraviolet absorbing material is contained.
In the case where the ultraviolet absorbing layer 13 includes only the material of the ultraviolet absorbing material group A as the ultraviolet absorbing material, it is preferable that the ultraviolet absorbing layer 13 includes the material of the ultraviolet absorbing material group A within the above range. Further, when the ultraviolet absorbing layer 13 includes the material of the ultraviolet absorbing material group A and the material of the ultraviolet absorbing material group B, the total of the material of the ultraviolet absorbing material group A and the material of the ultraviolet absorbing material group B is the above. It is preferable to be in the range. Further, when the ultraviolet absorbing layer 13 includes ultraviolet absorbing materials other than the ultraviolet absorbing material group A and the ultraviolet absorbing material group B, it is preferable that the total of all these ultraviolet absorbing materials falls within the above range.

(UV absorbing layer; other configurations)
In addition to the above-described ultraviolet absorbing material, the ultraviolet absorbing layer 13 includes a polymer material that serves as a medium for the ultraviolet absorbing material. As a polymer material that serves as a medium for the ultraviolet absorbing layer 13, a water-soluble polymer constituting the dielectric multilayer film 12 can be used.

In addition, it is preferable that a hindered amine light stabilizer is added to the ultraviolet absorbing layer 13 in order to further improve the light resistance of the ultraviolet absorbing layer. Since the hindered amine light stabilizer can suppress deterioration and coloring of the polymer resin compound, the coloring of the heat ray shielding film 10 can be suppressed low. The addition amount of the hindered amine-based additive is preferably 0.05 to 10% by mass in the ultraviolet absorbing layer 13.

Further, the ultraviolet absorbing layer 13 can also be configured to serve as the adhesive layer of the heat ray shielding film 10 by including an adhesive material such as an adhesive. When making the ultraviolet absorption layer 13 function as an adhesive layer, it is preferable to provide the ultraviolet absorption layer 13 as the outermost layer of the heat ray shielding film 10. Moreover, when making the 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 heat ray shielding film 10 is bonded to a window glass, a method of spraying water on the window and sticking the adhesive layer side of the heat ray shielding film 10 to a wet glass surface, the so-called water pasting 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 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 is increased, but also after being attached to glass and then peeled off, cohesive failure occurs between the adhesive layers, and the adhesive remains.

[Base material]
In the heat ray shielding film 10, if the base material 11 is a base material formed with the transparent organic material, it will not specifically limit. 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 the base material include cellulose nanofiber films. Furthermore, two or more layers of these base 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 that the diol component is a main component and has film-forming properties. 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.

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 11 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 heat ray shielding 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 can also be produced from an unstretched base material using a known method such as uniaxial stretching, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, and tubular-type simultaneous biaxial stretching. . 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 stretch film-forming process of the polyester film to the winding in the transverse stretch 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, the relaxation rate is 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.

Further, the above-described ultraviolet absorbing material may be included in the base material 11. In this case, the base material 11 can function as the ultraviolet absorbing layer 13, or the base material 11 and the ultraviolet absorbing layer 13 can be used in combination. For example, a configuration in which the ultraviolet absorbing layer 13 is provided on one side of the dielectric multilayer film 12 and the substrate 11 containing an ultraviolet absorbing material is provided on the other side can be adopted.

In this way, by sandwiching the dielectric multilayer film 12 with the layer containing the ultraviolet absorbing material, not only the direct light incident from the ultraviolet absorbing layer 13 side but also the reflected light incident from the substrate 11 side due to irregular reflection or the like. However, discoloration of the dielectric multilayer film 12 can be suppressed.

[Method for producing heat ray shielding film]
Next, the manufacturing method of the above-mentioned heat ray shielding film 10 is demonstrated. The heat ray shielding film 10 includes a step of forming a dielectric multilayer film 12 on a substrate 11 and a step of forming an ultraviolet absorption layer 13.

(Dielectric multilayer film formation process)
The method for forming the dielectric multilayer film 12 is not particularly limited. For example, a method of forming the dielectric multilayer film 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 given. It is done.

The method for preparing the coating solution for the high refractive index layer is not particularly limited, and examples thereof include a method of stirring and mixing a water-soluble polymer, metal oxide fine particles, a solvent, and other additives added as necessary. It is done. The method for preparing 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, metal oxide fine particles and other additives. It is done. 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 preparing each coating solution 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. And 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, 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%. Here, by setting it as 80 mass% or more, the volume fluctuation | variation by volatilization of a solvent can be reduced, and the operativity of coating-film formation improves. Moreover, by setting it as 99.9 mass% or less, the homogeneity of a coating liquid increases and the physical property of a coating liquid is stabilized.

Next, each prepared coating liquid is apply | coated on the base material 11, and it is made to dry. By performing the coating process and the drying process, a dielectric multilayer film can be formed from the coating film.
The coating method is not particularly limited, and may be either a sequential coating method or simultaneous multilayer coating, but simultaneous multilayer coating is preferable 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 at the time of simultaneous multilayer coating is preferably a temperature range of 25 to 60 ° C., more preferably a temperature range of 30 to 45 ° C. When the curtain coating method is used, 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, more preferably in the range of 10 to 50 mPa · s, in the preferable temperature range of each of the above coating solutions. . When the curtain coating method is used, it is preferably in the range of 5 to 1200 mPa · s, more preferably in the range of 25 to 500 mPa · s, in the preferable temperature range of the coating solution. If it is the range of such a viscosity, simultaneous multilayer coating can be performed efficiently.

Further, the viscosity at 15 ° C. of each coating solution is preferably 100 mPa · s or more, more preferably 100 to 30000 mPa · s, further preferably 3000 to 30000 mPa · s, and most preferably 10,000 to 30000 mPa · s. is there.

When the dielectric multilayer film 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 material. After coating on 11 and drying to form a layer, the other coating solution is coated on this layer and dried to form a layer. The dielectric multilayer film 12 is formed by repeating this process so that the number of layers necessary for expressing desired reflection performance is obtained.

Drying is preferably performed by drying 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 dielectric multilayer film 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 formation is performed. The temperature of the coated 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 method immediately after application | coating, it is preferable to carry out by a horizontal set system from a viewpoint of the uniformity improvement of the formed coating film.

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. Means a process. When the finger is pressed against the surface of the coating film, the state in which the finger is no longer attached 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.

In addition to changing the concentration of the water-soluble polymer contained in each coating solution and the concentration of the metal oxide fine particles, the set time includes various known gels such as gelatin, pectin, agar, carrageenan, and gellan gum. It can adjust by adding other components, such as an agent.

(Ultraviolet absorption layer forming process)
The ultraviolet absorbing layer 13 can be prepared by preparing an ultraviolet absorbing layer coating solution, and then applying and drying the coating solution.

The method for preparing the UV-absorbing layer coating solution is not particularly limited, and a method of stirring and mixing the above-described UV-absorbing material, water-soluble polymer, solvent, and additives and pressure-sensitive adhesives added as necessary. Can be 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 preparing the coating solution is not particularly limited, and a solvent similar to the solvent used for forming the dielectric multilayer film 12 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. In addition, as a method for applying the ultraviolet absorbing layer coating solution, a wet coating method that can be used for forming the dielectric multilayer film 12 may be used to apply the coating directly on the dielectric multilayer film 12.

In the case where the ultraviolet absorbing layer 13 also serves as an adhesive layer, it is applied directly to the dielectric multilayer film 12, and after being applied to release paper and dried, the ultraviolet absorbing layer 13 is then applied to the dielectric multilayer film. It may be transferred onto the film 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 ultraviolet absorbing 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 solution, 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., 3 days or longer is preferable. In the case of heating, if the temperature is raised too much, the flatness of the substrate 11 may be deteriorated.

<2. Embodiment of Heat Ray Shielding Film (Second Embodiment)>
Next, the heat ray shielding film of 2nd Embodiment is demonstrated. The schematic structure of the heat ray shielding film of 2nd Embodiment is shown in FIG. A heat ray shielding film 20 shown in FIG. 2 includes a base material 11, an infrared absorption layer 22 that is a heat ray shielding layer formed on one surface of the base material 11, and an ultraviolet absorption formed on the other surface of the base material 11. Layer 13. In addition, in the heat ray shielding film 20, the ultraviolet absorption layer 13 and the base material 11 can apply the structure similar to the above-mentioned 1st Embodiment.

The ultraviolet absorbing layer 13 is provided on the main surface of the substrate 11 opposite to the infrared absorbing layer 22. In the heat ray shielding film 20, the ultraviolet absorbing layer 13 side is a light incident (drawing arrow) surface. For this reason, the ultraviolet absorption layer 13 is disposed outside the infrared absorption layer 22 and the light incident surface side of the substrate 11.

[Heat ray shielding layer]
(Constitution)
The infrared absorbing layer 22 includes an infrared absorbing material and a polymer that is a medium (binder) of the infrared absorbing material. As the infrared absorbing material, fine particles of metal oxide (metal oxide particles) having an absorption region in the infrared wavelength region can be used.

(Metal oxide particles)
Metal oxide particles are particles having optical absorption characteristics that have absorption in the infrared wavelength region. In the infrared absorption layer 22, it is preferable to use metal oxide particles having large absorption particularly in an infrared region having a wavelength of 1000 nm or more. Examples of the metal oxide particles having a large absorption in an infrared region having a wavelength of 1000 nm or more include tungsten oxide and composite tungsten oxide. For this reason, it is preferable that the infrared absorption layer 22 includes at least one selected from tungsten oxide and composite tungsten oxide.

Tungsten oxide is represented by the general formula WyOz. However, in the general formula WyOz, W represents tungsten, O represents oxygen, and satisfies 2.2 ≦ z / y ≦ 2.999.

Among tungsten oxides WyOz, tungsten trioxide having oxygen vacancies, and so-called tungsten bronzes obtained by adding a positive element such as Na to tungsten trioxide are known to be conductive materials having free electrons. . These materials suggest a response of free electrons to light in the infrared region from analysis of single crystals and the like. That is, these materials have a particularly effective range as an infrared absorbing material in a specific composition range of tungsten and oxygen. Therefore, tungsten oxide particles and composite tungsten oxide particles having high transparency in the visible light region and large absorption in the near infrared region can be found in a specific composition range. In the infrared absorption layer 22, it is preferable to use these tungsten oxide particles and composite tungsten oxide particles as metal oxide particles (infrared absorbing material).

The composite tungsten oxide is represented by a general formula MxWyOz.
In the general formula MxWyOz, M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag , Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re , Be, Hf, Os, Bi, and I are one or more kinds of elements. W represents tungsten, O represents oxygen, and satisfies 0.001 ≦ x / y ≦ 1 and 2.2 ≦ z / y ≦ 3.

Since the composite tungsten oxide is excellent in durability in the crystal structure represented by the general formula MxWyOz, the composite tungsten oxide preferably includes one or more crystal structures selected from hexagonal crystals, tetragonal crystals, and cubic crystals. Among these, hexagonal crystals are suitable as infrared absorbing materials because they have the least absorption in the visible light region.

As the composite tungsten oxide having a hexagonal crystal structure, for example, one or more elements selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn as M elements The structure containing is mentioned. From the viewpoints of infrared shielding properties and weather resistance, the infrared absorption layer 22 preferably contains cesium-containing composite tungsten oxide as composite tungsten oxide.

In the composite tungsten oxide MxWyOz, if the value of x / y indicating the addition amount of the element M is larger than 0.001, a sufficient amount of free electrons is generated and the intended infrared shielding effect can be obtained. Further, as the amount of the element M added is increased, the supply amount of free electrons is increased and the infrared shielding efficiency is increased. However, when the value of x / y is about 1, the infrared shielding efficiency is saturated. Furthermore, if the value of x / y is 1 or less, generation of an impurity phase in the metal oxide particles can be avoided.

Also, the composite tungsten oxide MxWyOz has a particularly effective range as an infrared absorbing material in a specific composition range of tungsten and oxygen, similarly to the above-described tungsten oxide WyOz. Further, the composite tungsten oxide MxWyOz functions as an infrared absorbing material even when the value of z / y indicating the control of the amount of oxygen is 3.0 because free electrons are supplied by adding the element M described above. . Therefore, in the composite tungsten oxide MxWyOz, the value of z / y indicating the control of the oxygen amount is preferably 2.2 ≦ z / y ≦ 3.0, more preferably 2.45 ≦ z / y ≦ 3.0. It is.

The particle diameter of the metal oxide particles can be selected according to the purpose of use. In applications that require transparency, the metal oxide particles preferably have a particle size of 800 nm or less. Since particles smaller than 800 nm do not completely block light due to scattering, the transparency can be efficiently maintained.

Also, when importance is attached to the transparency in the visible light region, it is preferable to consider scattering by metal oxide particles. In order to reduce scattering by particles, the particle diameter is preferably 200 nm or less, preferably 100 nm or less. If the particle diameter of the metal oxide particles is small, the scattering of light in the visible light region having a wavelength of 400 to 780 nm due to geometric scattering or Mie scattering is reduced. Specifically, when the particle diameter of the metal oxide particles is 200 nm or less, geometrical scattering and Mie scattering are reduced, and the Rayleigh scattering region becomes dominant. In the Rayleigh scattering region, the scattered light is reduced in inverse proportion to the sixth power of the particle diameter, so that the scattering is reduced as the particle diameter is reduced, and the transparency of the heat ray shielding film 20 is improved. Furthermore, when the particle diameter of the metal oxide particles is 100 nm or less, the scattered light becomes very small. From the viewpoint of avoiding light scattering, a smaller particle diameter is preferable. Moreover, industrial manufacture is easy if a particle diameter is 1 nm or more.

By setting the particle diameter of the metal oxide particles to 800 nm or less, the heat ray shielding film 20 having a haze of 30% or less at a visible light transmittance of 85% or less can be formed. When the haze is 30% or less, the heat ray shielding film does not look like frosted glass, and clear transparency can be obtained.

As the metal oxide particles used for the infrared absorption layer 22, only one type of composite tungsten oxide or tungsten oxide may be used, or two or more types may be used in combination. Further, it may be used in combination with compound particles having optical absorption characteristics such as titanium oxide, cerium oxide, indium oxide, zinc sulfide, zinc oxide, anti-doped tin oxide (ATO), and tin-doped indium oxide (ITO). .

In addition, from the viewpoint of weather resistance and dispersibility, the metal oxide particles and the compound particles are oxides containing metals such as Si, Ti, Zr, Al, and the entire or part of the particle surface is covered. It is preferable that The method of coating the particles is not particularly limited, but the particle surface is coated with the oxide containing the coating metal by adding the alkoxide of the coating metal to a solution in which the metal oxide particles and compound particles are dispersed. be able to.

(polymer)
The polymer contained in the infrared absorbing layer 22 is not particularly limited, but silicone-based, acrylic-based, melamine-based, epoxy-based, acrylate-based, polyfunctional (meth) acrylic compounds, and the like are preferable. Here, (meth) acryl refers to acrylic and methacrylic.

In addition, an additive or the like can be included in the above polymer as necessary within a range that does not impair the effect of the heat ray shielding film 20. For example, dispersants, plasticizers, UV stabilizers, surfactants, antioxidants, flame retardants, preservatives, antioxidants, thermal stabilizers, lubricants, fillers, photoinitiators, photosensitizers, thermal polymerization Initiators, thickeners, coupling agents, antistatic agents, UV absorbing materials, leveling agents, adhesion modifiers, modifiers, or additives such as dyes and pigments to give any color tone may be included. . These may be used alone or in combination of two or more.

(Hard coat layer)
In order to impart scratch resistance to the surface, a hard coat layer is preferably disposed on the outermost layer of the heat ray shielding film 20. For this reason, in the heat ray shielding film 20, as shown in FIG. 2, when the infrared ray absorbing layer 22 is provided in the outermost layer of the heat ray shielding film 20, the infrared ray absorbing layer 22 can function as a hard coat layer. preferable. In order for the infrared absorbing layer 22 to function as a hard coat layer, an infrared absorbing material such as the above-described metal oxide particles may be included in the hard coat layer described below.

The hard coat layer is a layer having a pencil hardness of H to 8H. Particularly preferably, it is in the range of 2H to 6H. For pencil hardness, the prepared hard coat layer is conditioned at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours, and then the pencil hardness evaluation specified by JIS K 5400 is performed using a test pencil specified by JIS S 6006. Measure according to method.

The hard coat layer should be formed using an organic hard coat material such as silicone, melamine, epoxy, acrylate, or polyfunctional (meth) acrylic compound, or an inorganic hard coat material such as silicon dioxide. Can do. In particular, since the adhesive strength is high and the productivity is excellent, it is preferable to use a hard coat material of a (meth) acrylate-based or polyfunctional (meth) acrylic-based compound.

Further, in order to obtain high scratch resistance in the hard coat layer, it is preferable that a resin that cures through a crosslinking reaction is a main component. In particular, it is preferable that the hard coat layer is mainly composed of an actinic radiation curable resin.

As the active ray curable resin, it is preferable to use an ultraviolet curable resin. The ultraviolet curable resin is not particularly limited. For example, ADEKA OPTMER KR, BY series KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (above, Asahi Denka Kogyo Co., Ltd.) Manufactured by Koeihard Co., Ltd.), A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102 NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Industry Co., Ltd.), Seika Beam PHC2210 (S), PHCX-9 (K-3) ), PHC2213, DP-10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 Manufactured by Dainichi Seika Kogyo Co., Ltd.), KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above, Daicel UCB), RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.), Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sun Rad H-601R (manufactured by Sanyo Chemical Industries), SP-1509, SP-1507 (above, Showa Polymer Co., Ltd.), RCC-15C (Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (above, manufactured by Toagosei Co., Ltd.), or other commercially available products. For the coating composition containing these ultraviolet curable resins, an appropriate concentration is selected depending on the coating method, and for example, the solid content concentration can be used in the range of 10 to 95% by mass.

The light source for curing the ultraviolet curable resin is not particularly limited as long as it is a light source that generates ultraviolet rays. Irradiation conditions vary depending on the light source to be used. For example, the irradiation light amount can be about 20 to 1200 mJ / cm ² , preferably about 50 to 1000 mJ / cm ² . When a wavelength from the near ultraviolet region to the visible light region is used for curing the ultraviolet curable resin, it is preferable to use a sensitizer having an absorption maximum in that region.

The dry film thickness of the hard coat layer is preferably within the range of an average film thickness of 0.1 to 30 μm. Further, it is preferably in the range of 1 to 20 μm, particularly preferably in the range of 3 to 15 μm. When it is 3 μm or more, sufficient durability and impact resistance can be obtained. Moreover, from a viewpoint of flexibility or economical efficiency, 15 micrometers or less are preferable.

For example, the hard coat layer is prepared by dissolving an actinic radiation curable resin in an organic solvent to prepare a hard coat layer coating solution, and after applying the hard coat layer coating solution, irradiating actinic rays during or after drying. Can be formed. The method for applying the hard coat layer coating solution is not particularly limited, for example. Known methods such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, and an ink jet method can be used. Using these coating methods, it is preferable to form a coating film within a wet film thickness range of 0.1 to 100 μm.

In addition, inorganic or organic fine particles may be added to the hard coat layer coating solution in order to give the hard coat layer an antiglare property and to prevent adhesion with other substances and to improve scratch resistance and the like. . The average particle size of the added fine particles is preferably within a range of 0.01 to 10 μm. The fine particles are desirably blended so as to be in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin composition. In order to impart an antiglare effect, it is preferable to use 1 to 15 parts by mass of fine particles having an average particle size of 0.1 to 1 μm with respect to 100 parts by mass of the ultraviolet curable resin composition. Further, in order to impart an antiblocking function to the hard coat layer, 0.1 to 5 parts by mass of ultrafine particles having a volume average particle size in the range of 0.005 to 0.1 μm are added to 100 parts by mass of the resin composition. It can also be used.

In addition, in order to increase the heat resistance of the hard coat layer, an antioxidant with little suppression of the photocuring reaction can be used in the hard coat layer coating solution. Examples of the antioxidant that hardly suppresses the photocuring reaction include hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives, and the like. Specifically, for example, 4,4′-thiobis (6-tert-3-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4- Examples thereof include hydroxy-3,5-di-tert-butylbenzyl phosphate.

The hard coat layer coating solution may contain a solvent. Examples of the solvent include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (methyl acetate, ethyl acetate). , Methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used. The hard coat layer coating solution contains 5% by mass of propylene glycol monoalkyl ether (1 to 4 carbon atoms in the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms in the alkyl group). As described above, it is preferable to use an organic solvent contained in the range of 5 to 80% by mass.

The hard coat layer is preferably a layer having a good smooth surface with a centerline average surface roughness Ra ₇₅ specified by JIS B 0601 of less than 0.05 μm, more preferably less than 0.002 to 0.04 μm. . The center line average roughness (Ra ₇₅ ) is preferably measured with an optical interference type surface roughness measuring instrument, for example, using a non-contact surface fine shape measuring device (WYKO NT-2000) manufactured by WYKO. can do.

For the hard coat layer, a binder such as a known thermoplastic resin, thermosetting resin or hydrophilic resin such as gelatin can be mixed with the active energy ray curable resin and used. These resins preferably have a polar group in the molecule. The polar group includes —COOM, —OH, —NR ₂ , —NR ₃ X, —SO ₃ M, —OSO ₃ M, —PO ₃ M ₂ , —OPO ₃ M (where M is a hydrogen atom, alkali A metal or an ammonium group, X represents an acid that forms an amine salt, R represents a hydrogen atom or an alkyl group).
Further, various additives may be further blended in the hard coat layer as necessary. For example, an antioxidant, an ultraviolet stabilizer, an ultraviolet absorbing material, a surfactant, a leveling agent, an antistatic agent and the like can be used.

[Method for producing heat ray shielding film]
Next, the manufacturing method of the above-mentioned heat ray shielding film 20 is demonstrated. The heat ray shielding film 20 includes a step of forming the infrared absorption layer 22 on the base material 11 and a step of forming the ultraviolet absorption layer 13 on the base material 11.

(Heat ray shielding layer forming process)
The infrared absorption layer 22 can be prepared by preparing a heat ray shielding layer coating solution, and then applying and drying the coating solution.
The method for preparing the heat ray shielding layer coating liquid is not particularly limited, and, for example, the above-described infrared absorbing material, the above-described medium, polymer, solvent, and additives that are added as necessary are stirred and mixed. A method 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 coating method of the heat ray shielding layer coating solution is not particularly limited as long as the coating film can be uniformly formed on the surface of the substrate, and examples thereof include a bar coating method, a gravure coating method, a spray coating method, and a dip coating method.

The drying temperature and time of the coating film are not specified, but it is preferable that the solvent remaining in the infrared absorption layer 22 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.

(Ultraviolet absorption layer forming process)
Next, the ultraviolet absorption layer 13 is formed on the substrate 11. The ultraviolet absorbing layer 13 can be formed by the same method as the ultraviolet absorbing layer forming step of the heat ray shielding film of the first embodiment described above.
Through the above steps, the heat ray shielding film 20 having the configuration shown in FIG. 2 can be produced.

<3. Embodiment of Heat Shielding Film (Third Embodiment)>
Next, the structure of the heat ray shielding film of 3rd Embodiment is demonstrated. The schematic structure of the heat ray shielding film of 3rd Embodiment is shown in FIG.

The heat ray shielding film 30 shown in FIG. 3 includes a base material 11, an infrared absorption layer 22 formed on one surface of the base material 11, a dielectric multilayer film 12 formed on the other surface of the base material 11, And an ultraviolet absorbing layer 13 formed on the dielectric multilayer film 12. The heat ray shielding film 30 shown in FIG. 3 is different from the heat ray shielding film of the second embodiment described above only in the configuration having the dielectric multilayer film 12, and other configurations are the same as those of the heat ray shielding film of the second embodiment described above. A similar configuration can be applied. The configuration of the dielectric multilayer film 12 can be the same as the configuration of the dielectric multilayer film of the first embodiment described above.

The heat ray shielding film 30 includes an infrared absorption layer 22 and a dielectric multilayer film 12 as a heat ray shielding layer. Also in the heat ray shielding film 30, the ultraviolet ray absorbing layer 13 is provided on at least one surface of the main surface of the laminate composed of the base material 11 and the heat ray shielding layer (infrared absorbing layer 22, dielectric multilayer film 12). . As described above, the ultraviolet absorbing layer 13 is provided on one surface of the laminated body including the base material 11 and the heat ray shielding layer (the infrared absorbing layer 22 and the dielectric multilayer film 12) via another configuration. It may be. For example, the same applies to a configuration in which the ultraviolet absorbing layer 13 is formed on the surface of the infrared absorbing layer 22 in a laminate of the base material 11 and the heat ray shielding layer (the infrared absorbing layer 22 and the dielectric multilayer film 12).

The ultraviolet absorbing layer 13 is provided on the main surface side opposite to the infrared absorbing layer 22 with respect to the base material 11. The dielectric multilayer film 12 is provided on the main surface of the substrate 11 opposite to the infrared absorption layer 22. In the heat ray shielding film 30, the ultraviolet absorbing layer 13 side is a light incident (drawing arrow) surface. For this reason, the dielectric multilayer film 12 and the ultraviolet absorbing layer 13 are disposed outside the infrared absorbing layer 22 and the light incident surface side of the substrate 11.

Hereinafter, although an Example is given and a heat ray shielding film is demonstrated concretely, a heat ray shielding film is not limited to these.

<Preparation of heat ray shielding film of sample 101>
By the following method, a dielectric multilayer film in which a high refractive index layer and a low refractive index layer were alternately laminated and an adhesive layer were formed on a substrate, and a heat ray shielding film was produced. As the adhesive layer, an adhesive layer containing an ultraviolet absorbing material and functioning as an ultraviolet absorbing layer, or an adhesive layer not containing an ultraviolet absorbing material was formed.

[Preparation of coating solution for low refractive index layer]
A coating solution for a low refractive index layer was prepared as follows.
380 parts by mass of colloidal silica (10% by mass) (Snowtex OXS, average particle size of primary particles = 4 to 6 nm, manufactured by Nissan Chemical Industries, Ltd.), 50 parts by mass of boric acid aqueous solution (3% by mass), 300% by mass Parts of polyvinyl alcohol (4% by mass) (JP-45, degree of polymerization: 4500, degree of saponification: 88 mol%, manufactured by Nihon Acetate Bipoval Co., Ltd.), 3 parts by weight of surfactant (5% by mass) (softazoline LSB-R (manufactured by Kawaken Fine Chemical Co., Ltd.) was added in this order at 45 ° C. and mixed. And it finished to 100 mass parts with pure water, and prepared the coating liquid for low refractive index layers.

[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.

(Preparation 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.

[Formation of dielectric multilayer film on substrate]
A substrate (thickness 50 μm) heated to 45 ° C. while keeping the coating solution for low refractive index layer and the coating solution for high refractive index layer obtained by the above method at 45 ° C. using a slide hopper coating apparatus. No. 11 polyethylene terephthalate film (Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) was subjected to simultaneous multilayer coating (total thickness of dielectric multilayer film: 1.5 μm). At this time, the lowermost layer and the uppermost layer were low refractive index layers, and the other layers were formed such that low refractive index layers and high refractive index layers were alternately laminated. The coating amount was adjusted so that the low refractive index layer had a thickness of 150 nm and the high refractive index layer had a thickness of 120 nm. The film thickness was confirmed by cutting the manufactured laminate (base material and dielectric multilayer film) and observing the cut surface with an electron microscope. At this time, when the interface between the two layers could not be clearly observed, the interface was determined by the XPS profile in the thickness direction of TiO ₂ contained in the layer obtained by the XPS surface analyzer.

Immediately after application, it was set by blowing cold air of 5 ° C. At this time, even if the surface was touched with a finger, the time until the finger was lost (set time) was 5 minutes. After completion of the setting, warm air of 80 ° C. was blown and dried to form an eleven-layer dielectric multilayer film on the substrate.

[Formation of adhesive layer]
(Composition of adhesive layer coating solution)
N2147 (solid content 35%) manufactured by Nippon Synthetic Chemical Industry as an adhesive is 100 parts by mass, and BONASORB-3911 (solid content 100%) (indole compound) manufactured by Orient Chemical is 0.89 parts by mass as an ultraviolet absorbing material. Then, 1.0 part by mass of Coronate HL (solid content 75%) manufactured by Nippon Polyurethane Industry, an isocyanate curing agent, was mixed to prepare an adhesive layer coating solution. In addition, this adhesion layer coating liquid was adjusted so that 2 mass% of said ultraviolet-absorbing materials were contained in the adhesion layer after formation.

(Preparation of adhesive layer)
Apply the above adhesive layer coating solution on the silicone release surface of Nakamoto Pax's separator NS23MA with a comma coater to a dry film thickness of 10 μm, and dry at 90 ° C. for 1 minute to form an adhesive layer did.
The adhesive multilayer film formed on the base material by the above-mentioned method was bonded to this adhesive layer, and the adhesive layer was formed on the dielectric multilayer film.
As described above, a heat ray shielding film of Sample 101 in which a base material, a dielectric multilayer film, and an adhesive layer (containing an ultraviolet absorber) were laminated in this order was produced.

<Preparation of heat ray shielding film of sample 102>
In preparation of the above-mentioned sample 101, the above-mentioned thing except having used the 25-micrometer-thick polyethylene terephthalate (PET) film (Tetron (trademark) film HB by Teijin DuPont Films) containing the ultraviolet absorption material as a substrate. A heat ray shielding film of Sample 102 was produced in the same manner as Sample 101.

<Preparation of heat ray shielding film of sample 103>
In the preparation of the sample 101 described above, the adhesive layer was composed of 2% by mass of BONASORB-3701 (indole compound) manufactured by Orient Chemical Industry and 6% by mass of TINUVIN 477 (triazine compound) manufactured by BASF as an ultraviolet absorbing material. A heat ray shielding film of Sample 103 was produced in the same manner as Sample 101 described above, except that it was formed (the total amount of ultraviolet absorbing material was 8% by mass).

<Preparation of heat ray shielding film of sample 104>
In the preparation of the sample 101 described above, a heat ray shielding film of the sample 104 was prepared in the same manner as the sample 101 described above except that the thickness of the adhesive layer was changed to 30 μm.

<Preparation of heat ray shielding film of sample 105>
A heat ray shielding film of Sample 105 was prepared in the same manner as Sample 101 described above except that the thickness of the adhesive layer was set to 35 μm in the preparation of Sample 101 described above.

<Preparation of heat ray shielding film of sample 106>
A heat ray shielding film of Sample 106 was prepared in the same manner as Sample 101 described above except that the thickness of the adhesive layer was set to 1 μm in the preparation of Sample 101 described above.

<Preparation of heat ray shielding film of sample 107>
A heat ray shielding film of Sample 107 was prepared in the same manner as Sample 101 described above except that the thickness of the adhesive layer was changed to 0.5 μm in the preparation of Sample 101 described above.

<Preparation of heat ray shielding film of sample 108>
A heat ray shielding film of Sample 108 was prepared in the same manner as Sample 101 described above except that the adhesive layer was formed so that the content of the ultraviolet absorbing material was 15% by mass in the preparation of Sample 101 described above.

<Preparation of heat ray shielding film of sample 109>
In the preparation of the sample 101 described above, a heat ray shielding film of the sample 109 was prepared in the same manner as the sample 101 described above, except that the adhesive layer was formed so that the content of the ultraviolet absorbing material was 0.1% by mass. did.

<Preparation of heat ray shielding film of sample 110>
In the preparation of the sample 101 described above, a heat ray shielding film of the sample 110 was prepared in the same manner as the sample 101 described above, except that the adhesive layer was formed so that the content of the ultraviolet absorbing material was 0.05% by mass. did.

<Preparation of heat ray shielding film of sample 111>
In the preparation of the sample 101 described above, the sample was prepared in the same manner as the sample 101 described above, except that the content of the ultraviolet absorbing material contained in the adhesive layer was 0.02 parts by mass as the ultraviolet absorbing material contained in the adhesive layer. 111 heat ray shielding film was produced.

<Preparation of heat ray shielding film of sample 112>
In the preparation of the above-described sample 101, the adhesive layer is composed of 2% by mass of BONASORB-3911 (indole compound) manufactured by Orient Chemical Industry and 6% by mass of TINUVIN 234 (benzotriazole compound) manufactured by BASF as an ultraviolet absorbing material. The heat ray shielding film of the sample 112 was produced by the same method as the above-mentioned sample 101 except that it was formed in the same manner (except that the total amount of the ultraviolet absorbing material was 8% by mass).

<Preparation of heat ray shielding film of sample 113>
In the preparation of the above-described sample 101, the adhesive layer is composed of 2% by mass of BONASORB-3911 (indole compound) manufactured by Orient Chemical Industry and 6% by mass of LA-1413 (benzophenone compound) manufactured by ADEKA as an ultraviolet absorbing material. A heat ray shielding film of Sample 113 was produced in the same manner as Sample 101 described above except that the film was formed in the same manner (except that the total amount of the ultraviolet absorbing material was 8 mass%).

<Preparation of heat ray shielding film of sample 114>
In the preparation of the sample 105 described above, a heat ray shielding film of the sample 114 was prepared in the same manner as the sample 105 described above except that the content of the ultraviolet absorbing material contained in the adhesive layer was 0.02 parts by mass.

<Preparation of heat ray shielding film of sample 115>
In the preparation of the sample 103 described above, a heat ray shielding film of the sample 115 was prepared by the same method as the sample 103 described above, except that the thickness of the adhesive layer was set to 0.5 μm.

<Preparation of heat ray shielding film of sample 116>
In the preparation of the sample 101 described above, the adhesive layer was formed in the same manner as the sample 101 described above except that the S0511 (merocyanine compound) manufactured by FEW CHEMICALS was 2.0% by mass as an ultraviolet absorbing material. A heat ray shielding film of Sample 116 was produced.

<Preparation of heat ray shielding film of sample 117>
In the preparation of the sample 101 described above, the sample was prepared in the same manner as the sample 101 described above, except that the adhesive layer was formed so that S2142 (coumarin compound) manufactured by FEW CHEMICALS was 2.0% by mass as an ultraviolet absorbing material. 117 heat ray shielding film was produced.

<Preparation of heat ray shielding film of sample 118>
In the preparation of the sample 101 described above, the adhesive layer was formed in the same manner as the sample 101 described above, except that BONASORB-3701 (azomethine compound) manufactured by Orient Chemical Co., Ltd. was used as an ultraviolet absorbing material so as to be 2% by mass. A heat ray shielding film of Sample 118 was produced.

<Preparation of heat ray shielding film of sample 119>
In the preparation of the sample 101 described above, the adhesive layer was the same as the sample 101 described above except that the adhesive layer was formed to have a thickness of 40 μm and 7% by mass of TINUVIN 477 (triazine compound) manufactured by BASF as an ultraviolet absorbing material. The heat ray shielding film of sample 119 was produced by the method.

<Preparation of heat ray shielding film of sample 120>
In the preparation of the sample 101 described above, the adhesive layer was formed in the same manner as the sample 101 described above except that the adhesive layer was formed such that BONASORB-3911 (indole compound) manufactured by Orient Chemical Co., Ltd. was 17% by mass. A heat ray shielding film of Sample 120 was produced.

<Preparation of heat ray shielding film of sample 121>
In the preparation of the sample 101 described above, the adhesive layer was formed in the same manner as the sample 101 described above except that the adhesive layer was formed so that TINUVIN 477 (triazine compound) manufactured by BASF was 5% by mass. A heat ray shielding film was produced.

<Preparation of heat ray shielding film of sample 122>
In the preparation of the sample 101 described above, a 25 μm thick polyethylene terephthalate (PET) film (Tetron (registered trademark) film HB manufactured by Teijin DuPont Films) containing an ultraviolet absorbing material was used as a base material, and an adhesive layer was further used. Was formed without containing the ultraviolet absorbing material, and a heat ray shielding film of Sample 122 was produced in the same manner as Sample 101 described above.

<Preparation of heat ray shielding film of sample 123>
In the preparation of the sample 101 described above, the adhesive layer was formed so that BASF TINUVIN 234 (triazine compound) was 4% by mass and BASF TINUVIN 477 (benzotriazole compound) was 6% by mass as the ultraviolet absorbing material. Except for the above, a heat ray shielding film of Sample 123 was produced in the same manner as Sample 101 described above.

<Evaluation>
[UV transmittance of adhesive layer]
Using a spectrophotometer U-4000 type (using an integrating sphere, manufactured by Hitachi, Ltd.) by a method according to JIS R3106-1998, the maximum transmittance (% )

[Visible light transmittance of heat ray shielding film]
Using a spectrophotometer U-4000 type (using an integrating sphere, manufactured by Hitachi, Ltd.) by a method according to JIS R3106-1998, the minimum transmittance of the heat ray shielding film of each sample in the wavelength range of 420 to 780 nm ( %).

[Discoloration (ΔE)]
Each sample of the produced heat ray shielding film was affixed on the blue glass of thickness 3mm through the adhesive layer. 100 W / with respect to this sample, using a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd .; emits light very close to sunlight) from the adhesive layer (ultraviolet absorption layer) side of the sample under the conditions of 30 ° C. and 60% RH. Xenon light with an intensity of m ² was exposed for 2000 hours, and the color difference (ΔE) was calculated from the difference in transmitted light before and after exposure. A smaller value of ΔE means that the degree of coloring due to exposure to xenon light is smaller.
The transmitted light of the sample before and after exposure is evaluated by the transmittance in the wavelength range of 200 to 2000 nm using a spectrophotometer U-4000 type (integrating sphere, manufactured by Hitachi, Ltd.) according to a method according to JIS R3106-1998. did.

Table 1 shows the evaluation results of the heat ray shielding films of Samples 101 to 124.

As shown in Table 1, the sample has a maximum transmittance at a wavelength of 350 to 400 nm of an ultraviolet absorbing layer (adhesive layer) of 40% or less and a minimum transmittance of a heat ray shielding film at a wavelength of 420 to 780 nm satisfies 40% or more. The heat ray shielding films 101 to 119 have a smaller degree of discoloration than the samples 120 to 123 that do not satisfy the above conditions.

From this result, it can be seen that, when the heat ray shielding film has an ultraviolet absorbing layer satisfying the above conditions, discoloration of titanium oxide contained in the dielectric multilayer film can be suppressed, and deterioration of the light transmission characteristics of the heat ray shielding film can be suppressed.

In the sample 102 using the base material containing the ultraviolet absorbing material, the same result as the sample 101 using the PET base material was obtained. From this result, it is also possible to use a substrate containing an ultraviolet absorbing material.

An ultraviolet absorbing material (triazine compound, benzotriazole compound, benzophenone compound) having an absorbing region on the shorter wavelength side than wavelength 380 to 400 nm is used together with an ultraviolet absorbing material (indole compound) having an absorbing region at a wavelength of 380 to 400 nm. The sample 103, the sample 112, and the sample 113 that are present have very small discoloration of the heat ray shielding film. As described above, the combined use of the ultraviolet absorbing material having the absorption region at the wavelength of 380 to 400 nm and the ultraviolet absorbing material having the absorption region on the shorter wavelength side than the wavelength of 380 to 400 nm suppresses the discoloration of the heat ray shielding film. It is possible to suppress the deterioration of the optical properties of the heat ray shielding film.

From the results of Sample 101 and Samples 104 to 107, if the content of the ultraviolet absorbing material is the same, if the thickness of the ultraviolet absorbing layer (adhesive layer) is small, the discoloration degree deteriorates, and if the thickness is large, the initial value is obtained. Visible light transmittance tends to decrease. Further, from the results of the samples 103 and 115, even when a plurality of types of ultraviolet absorbing materials are used, the discoloration degree deteriorates when the thickness of the ultraviolet absorbing layer (adhesive layer) is small. From this result, it is preferable to set the thickness of the ultraviolet absorbing layer to 1 μm to 30 μm in order to facilitate the coexistence of the color change degree and the visible light transmittance of the heat ray shielding film.

Further, from the results of Sample 101 and Samples 108 to 111, if the thickness of the UV absorbing layer (adhesive layer) is the same, if the content of the UV absorbing material is small, the degree of discoloration deteriorates and the content is large. The initial visible light transmittance tends to decrease. For this reason, in order to facilitate the coexistence of the color change degree and the visible light transmittance of the heat ray shielding film, the content of the ultraviolet absorbing layer is preferably 0.05 to 15% by mass.

Samples 116, 117, and 118 using merocyanine compound, coumarin compound, or azomethine compound as the ultraviolet absorbing material showed the same results as those of sample 101 using the indole compound as the ultraviolet absorbing material. . From this result, if the maximum transmittance of the wavelength 350 to 400 nm of the ultraviolet absorbing layer (adhesive layer) is 40% or less and the minimum transmittance of the heat ray shielding film wavelength of 420 to 780 nm is 40% or more, Regardless of the type of ultraviolet absorbing material, it can be used for a heat ray shielding film.

Also in the sample 119 using the triazine compound as the ultraviolet absorbing material, the maximum transmittance at a wavelength of 350 to 400 nm of the ultraviolet absorbing layer (adhesive layer) is 40% or less, and the minimum transmittance of the heat ray shielding film at a wavelength of 420 to 780 nm is low. By satisfying 40% or more, visible light transmittance and discoloration sufficient for a heat ray shielding film are obtained. Also from this result, the maximum transmittance of the ultraviolet absorbing layer (adhesive layer) at a wavelength of 350 to 400 nm is 40% or less, and the minimum transmittance of the heat ray shielding film at a wavelength of 420 to 780 nm is 40% or more. It turns out that it can be used for a heat ray shielding film regardless of the kind of ultraviolet absorbing material.

On the other hand, the sample 120 in which the minimum transmittance at a wavelength of 420 to 780 nm of the heat ray shielding film does not satisfy 40% or more has a low initial visible light transmittance. In addition, the degree of discoloration is bad. Since the sample 120 has an excessive content of the UV absorbing material, the minimum transmittance of the heat ray shielding film at a wavelength of 420 to 780 nm is a low value of 34%. For this reason, the initial visible light transmittance is low, and sufficient transparency as a heat ray shielding film cannot be secured.

In addition, the samples 121 to 123 in which the maximum transmittance at a wavelength of 350 to 400 nm of the ultraviolet absorbing layer (adhesive layer) does not satisfy 40% or less have a low degree of discoloration. In particular, the sample 122 having no ultraviolet absorbing material in the adhesive layer has the highest initial visible light transmittance, but the worst color change. That is, since it is a structure which does not have an ultraviolet-absorbing material, the discoloration of the titanium oxide contained in a dielectric multilayer film is large, and the optical characteristic of a heat ray shielding film will fall large.

<Preparation of heat ray shielding film of sample 201>
On one surface of a base material (polyethylene terephthalate film having a thickness of 50 μm, Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.), a heat ray shielding layer coating solution A prepared by the following method was applied with a gravure coater, and 1 at 90 ° C. Let dry for minutes. Next, using an ultraviolet lamp, the coating film is cured by irradiating ultraviolet rays from the surface far from the base material of the coating film under the conditions of illuminance of 100 mW / cm ² , irradiation amount of 0.2 J / cm ² , and oxygen concentration of 200 ppm. Thus, a hard coat layer (heat ray shielding layer) was formed. The thickness of the hard coat layer was appropriately adjusted so that the visible light (wavelength: 450 nm to 600 nm) transmittance was 68%.

Next, the adhesive layer coating solution B prepared by the following method was applied to the silicone release surface of Nakamoto Pax NS23MA with a comma coater so that the dry film thickness was 10 μm. An adhesive layer (ultraviolet absorption layer) was formed by drying for 1 minute. Then, this adhesive layer (ultraviolet absorption layer) is bonded to the other surface (surface opposite to the hard coat layer) of the base material on which the hard coat layer is formed by the above-described method, and a heat ray shielding film of sample 201 is produced. did.

[Heat ray shielding layer coating solution A]
390 parts by mass of UV curable Aronix (registered trademark) M-405 (manufactured by Toagosei Co., Ltd.) and 0.4 part by mass of EBECRYL (registered trademark) 350 (manufactured by Daicel Ornex Co., Ltd.) were mixed, and carbon black ( CB) 5 parts by mass of a dispersion (KCF-22, manufactured by Sumitomo Metal Mining) and 450 parts by mass of methyl ethyl ketone as a solvent were added. Furthermore, as a polymerization initiator, 20 parts by mass of Irgacure (registered trademark) 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of fluorosurfactant surfactant (registered trademark) 650A (manufactured by Neos Co., Ltd.) were added. Then, a heat ray shielding layer coating solution A was prepared.

[Adhesive layer coating solution B]
100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industry) as an adhesive, 2 parts by mass of S0511 (merocyanine compound, manufactured by FEW CHEMICALS) as a UV-absorbing material, TINUVIN 477 (triazine compound, manufactured by BASF) 7 parts by weight and 1.0 part by weight of Coronate HL (solid content 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.), an isocyanate curing agent, were mixed to prepare an adhesive layer coating solution B.

<Preparation of heat ray shielding film of sample 202>
A heat ray shielding film of Sample 202 was produced in the same manner as Sample 201, except that in the production of the heat ray shielding film of Sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 42%.

<Preparation of heat ray shielding film of sample 203>
In preparation of the heat ray shielding film of the above-mentioned sample 201, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 42%, and the adhesive layer coating solution B was prepared by the following method. A heat ray shielding film of Sample 203 was produced in the same manner as Sample 201 except that the sample was changed to C.

[Adhesive layer coating solution C]
100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industry) as an adhesive, 2 parts by mass of S2142 (coumarin compound, manufactured by FEW CHEMICALS) as a UV absorbing material, TINUVIN 477 (manufactured by BASF) 7 parts by mass and 1.0 part by mass of Coronate HL (solid content 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.), an isocyanate curing agent, were mixed to prepare an adhesive layer coating solution C.

<Preparation of heat ray shielding film of sample 204>
In the production of the heat ray shielding film of the sample 201 described above, the sample was the same as the sample 201 except that the thickness of the hard coat layer was adjusted so that the visible light transmittance was 72% and the thickness of the adhesive layer was adjusted to 15 μm. 204 heat ray shielding films were produced.

<Preparation of heat ray shielding film of sample 205>
In preparation of the heat ray shielding film of the sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 85%, and the thickness of the adhesive layer was adjusted so as to be 15 μm. A heat ray shielding film of sample 205 was prepared.

<Preparation of heat ray shielding film of sample 206>
In the production of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution B prepared by the following method, and the thickness of the hard coat layer becomes 72% visible light transmittance. A heat ray shielding film of Sample 206 was produced in the same manner as Sample 201 except that the adjustment was made as described above.

[Heat ray shielding layer coating solution B]
Ultraviolet curable Aronix (registered trademark) M-405 (manufactured by Toagosei Co., Ltd.) (390 parts by mass) and EBECRYL (registered trademark) 350 (manufactured by Daicel Ornex Co., Ltd.) (0.4 parts by mass) were mixed, and ATO (antimony) was mixed. 650 parts by mass of doped tin oxide, manufactured by ANP, SR35M, average particle size: 15 nm), and 300 parts by mass of methyl ethyl ketone as a solvent were added. Furthermore, as a polymerization initiator, 20 parts by mass of Irgacure (registered trademark) 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of a fluorosurfactant (phthalent (registered trademark) 650A (manufactured by Neos Corporation) were added. Thus, a heat ray shielding layer coating solution B was prepared.

<Preparation of heat ray shielding film of sample 207>
In the production of the heat ray shielding film of the above-described sample 201, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution B, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 72%. A heat ray shielding film of Sample 207 was produced in the same manner as Sample 201 except that the layer coating solution B was changed to the adhesive layer coating solution C.

<Preparation of heat ray shielding film of sample 208>
In the production of the heat ray shielding film of the above-described sample 201, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution B, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 72%. A heat ray shielding film of Sample 208 was produced in the same manner as Sample 201 except that the layer coating solution B was changed to the adhesive layer coating solution A prepared by the following method.

[Adhesive layer coating solution A]
100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industries) as an adhesive, 2 parts by mass of BONASORB-3912 (100% solids, indole compound, manufactured by Orient Chemical Industries), TINUVIN 7 parts by weight of 477 (triazine compound, manufactured by BASF) and 1.0 part by weight of coronate HL (solid content 75%, manufactured by Nippon Polyurethane Industry), an isocyanate curing agent, were mixed to prepare an adhesive layer coating solution A. did.

<Preparation of heat ray shielding film of sample 209>
In the production of the heat ray shielding film of the above-described sample 201, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution B, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 72%. A heat ray shielding film of Sample 209 was produced in the same manner as Sample 201, except that the layer coating solution B was changed to the adhesive layer coating solution D prepared by the following method.

[Adhesive layer coating solution D]
100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industry) as an adhesive, and 0.89 mass of BONASORB-3911 (100% solid content, indole compound, manufactured by Orient Chemical Industries) as an ultraviolet absorbing material Part, 7 parts by mass of TINUVIN 477 (triazine compound, manufactured by BASF) and 1.0 part by mass of Coronate HL (solid content 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.), an isocyanate-based curing agent, were mixed. D was adjusted.

<Preparation of heat ray shielding film of sample 210>
In the production of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution D prepared by the following method, and the thickness of the hard coat layer becomes 43% visible light transmittance. Thus, a heat ray shielding film of Sample 210 was prepared in the same manner as Sample 201 except that the adhesive layer coating solution B was changed to the adhesive layer coating solution A.

[Heat ray shielding layer coating solution D]
390 parts by mass of UV curable Aronix (registered trademark) M-405 (manufactured by Toagosei Co., Ltd.) and 0.4 part by mass of EBECRYL (registered trademark) 350 (manufactured by Daicel Ornex Co., Ltd.) were mixed, and carbon black ( CB) Dispersion (KCF-22, manufactured by Sumitomo Metal Mining Co., Ltd.) 5 parts by mass, cesium-containing tungsten oxide as cesium doped tungsten oxide dispersion YMF-02A (total solid concentration 28 mass%, cesium doped tungsten oxide particles A concentration of 18.5% by mass, composition: Cs _0.33 WO ₃ , manufactured by Sumitomo Metal Mining Co., Ltd.) 650 parts by mass, and 300 parts by mass of methyl ethyl ketone as a solvent were added. Furthermore, as a polymerization initiator, 20 parts by mass of Irgacure (registered trademark) 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of fluorosurfactant surfactant (registered trademark) 650A (manufactured by Neos Co., Ltd.) were added. Then, a heat ray shielding layer coating solution D was prepared.

<Preparation of heat ray shielding film of sample 211>
In the preparation of the heat ray shielding film of the above-described sample 201, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution D, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 43%. A heat ray shielding film of Sample 211 was prepared in the same manner as Sample 201 except that the layer coating solution B was changed to the adhesive layer coating solution D.

<Preparation of heat ray shielding film of sample 212>
In the production of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution C prepared by the following method, and the visible light transmittance becomes 72% with respect to the thickness of the hard coat layer. Thus, a heat ray shielding film of Sample 212 was prepared in the same manner as Sample 201 except that the adhesive layer coating solution B was changed to the adhesive layer coating solution D.

[Heat ray shielding layer coating solution C]
390 parts by mass of UV curable Aronix (registered trademark) M-405 (manufactured by Toagosei Co., Ltd.) and 0.4 part by mass of EBECRYL (registered trademark) 350 (manufactured by Daicel Ornex Co., Ltd.) are mixed, and cesium-containing oxidation Cesium-doped tungsten oxide dispersion YMF-02A as tungsten (total solid content concentration 28% by mass, concentration of cesium-doped tungsten oxide particles 18.5% by mass, composition: Cs _0.33 WO ₃ , manufactured by Sumitomo Metal Mining Co., Ltd. ) 650 parts by mass and 300 parts by mass of methyl ethyl ketone as a solvent were added. Furthermore, as a polymerization initiator, 20 parts by mass of Irgacure (registered trademark) 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of fluorosurfactant surfactant (registered trademark) 650A (manufactured by Neos Co., Ltd.) were added. A heat ray shielding layer coating solution C was prepared.

<Preparation of heat ray shielding film of sample 213>
In the preparation of the heat ray shielding film of the above-described sample 201, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution C, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 72%. A heat ray shielding film of Sample 213 was produced in the same manner as Sample 201 except that the layer coating solution B was changed to the adhesive layer coating solution A.

<Preparation of heat ray shielding film of sample 214>
In the preparation of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution C, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 85%, A heat ray shielding film of sample 214 was produced in the same manner as sample 201 except that layer coating solution B was changed to adhesive layer coating solution D.

<Preparation of heat ray shielding film of sample 215>
In the preparation of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to the heat ray shielding layer coating solution C, and the thickness of the hard coat layer is adjusted so that the visible light transmittance is 85%, A heat ray shielding film of Sample 215 was produced in the same manner as Sample 201 except that the layer coating solution B was changed to the adhesive layer coating solution A.

<Preparation of heat ray shielding film of sample 216>
In the preparation of the heat ray shielding film of the sample 201 described above, the substrate was changed to a substrate with a dielectric multilayer film (reflective layer) produced by the following method, and the heat ray shielding layer coating solution A was changed to the heat ray shielding layer coating solution C. The thickness of the hard coat layer was adjusted so that the visible light transmittance was 72%, and the adhesive layer coating solution B was changed to the adhesive layer coating solution D except that the sample 216 was changed. A heat ray shielding film was produced.

[Coating liquid for low refractive index layer]
380 parts by mass of colloidal silica (10% by mass, Snowtex OXS, average particle size of primary particles = 4 to 6 nm, manufactured by Nissan Chemical Industries, Ltd.), 50 parts by mass of boric acid aqueous solution (3% by mass), 300 parts by mass Polyvinyl alcohol (4% by mass, JP-45, polymerization degree: 4500, saponification degree: 88 mol%, manufactured by Nihon Vitamin Pover Co., Ltd.), 3 parts by mass of surfactant (5% by mass, SOFTAZOLINE LSB-R) , Manufactured by Kawaken Fine Chemical Co., Ltd.) in this order at 45 ° C. and mixed. And it finished to 100 mass parts with pure water, and prepared the coating liquid for low refractive index layers.

[High refractive index layer coating solution]
(Preparation of silica-attached titanium dioxide sol)
After adding 2 parts by mass of pure water to 0.5 parts by mass of 15.0% by mass titanium oxide sol (SRD-W, volume average particle size: 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.), Heated. Next, 0.5 parts by mass of an aqueous silicic acid solution (sodium silicate No. 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 to obtain a titanium dioxide sol (silica-attached titanium dioxide sol) (volume average particle size: 9 nm) having SiO ₂ with a solid content concentration of 6% by mass attached to the surface. It was.

(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 mass%) 113 mass Then, 0.4 parts by mass of a 5% by weight aqueous solution of surfactant (SOFTAZOLINE LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) was added to prepare a high refractive index layer coating solution.

[Production of substrate with dielectric multilayer film (reflection layer)]
A substrate (thickness 50 μm) heated to 45 ° C. while keeping the coating solution for low refractive index layer and the coating solution for high refractive index layer obtained by the above method at 45 ° C. using a slide hopper coating apparatus. No. 11 polyethylene terephthalate film (Toyobo Co., Ltd., Cosmo Shine A4300) was applied to 11 layers simultaneously (total thickness of reflective layer: 1.5 μm). At this time, the lowermost layer and the uppermost layer were low refractive index layers, and the other layers were formed such that low refractive index layers and high refractive index layers were alternately laminated. The coating amount was adjusted so that the low refractive index layer had a thickness of 150 nm and the high refractive index layer had a thickness of 120 nm. The film thickness was confirmed by cutting the manufactured laminate (base material and dielectric multilayer film) and observing the cut surface with an electron microscope. At this time, when the interface between the two layers could not be clearly observed, the interface was determined by the XPS profile in the thickness direction of TiO ₂ contained in the layer obtained by the XPS surface analyzer.
Immediately after application, 5 ° C. cold air was blown and set. At this time, even if the surface was touched with a finger, the time until the finger was lost (set time) was 5 minutes. After completion of the setting, hot air of 80 ° C. was blown and dried to form a dielectric multilayer film consisting of 11 layers on the substrate, and a substrate with a dielectric multilayer film (reflection layer) was produced.

<Preparation of heat ray shielding film of sample 217>
In the production of the heat ray shielding film of the sample 201 described above, the base material is changed to a base material with a dielectric multilayer film (reflective layer), the heat ray shielding layer coating liquid A is changed to the heat ray shielding layer coating liquid C, and the hard coat layer The heat ray shielding film of Sample 217 was produced in the same manner as Sample 201, except that the thickness of the film was adjusted so that the visible light transmittance was 72% and the adhesive layer coating solution B was changed to the adhesive layer coating solution A. .

<Preparation of heat ray shielding film of sample 218>
In preparation of the heat ray shielding film of the sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 85%, and the adhesive layer coating solution B was prepared by the following method. A heat ray shielding film of Sample 218 was produced in the same manner as Sample 201 except that the sample was changed to E.

[Adhesive layer coating solution E]
100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industry) as an adhesive, 7 parts by mass of TINUVIN 477 (triazine compound, manufactured by BASF) as an ultraviolet absorbing material, and coronate HL of an isocyanate curing agent 1.0 part by mass (solid content: 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.) was mixed to prepare adhesive layer coating solution E.

<Preparation of Sample 219 Heat Shielding Film>
In the preparation of the heat ray shielding film of the sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 85%, the adhesive layer coating liquid B was changed to the adhesive layer coating liquid D, and the adhesive A heat ray shielding film of Sample 219 was produced in the same manner as Sample 201 except that the thickness of the layer was 5 μm.

<Preparation of heat ray shielding film of sample 220>
In the preparation of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A is changed to a clear hard coat (CHC) solution prepared by the following method, and the thickness of the hard coat layer is adjusted to 2 μm, A heat ray shielding film of Sample 220 was prepared in the same manner as Sample 201 except that the adhesive layer coating solution B was changed to the adhesive layer coating solution E.

[Clear hard coat solution]
Ultraviolet curable Aronix (registered trademark) M-405 (manufactured by Toagosei Co., Ltd.) 390 parts by mass and EBECRYL (registered trademark) 350 (manufactured by Daicel Ornex Co., Ltd.) 0.4 parts by mass were mixed, and methyl ethyl ketone as a solvent. 300 parts by weight were added. Furthermore, as a polymerization initiator, 20 parts by mass of Irgacure (registered trademark) 819 (manufactured by BASF Japan Ltd.) and 0.5 part by mass of fluorosurfactant surfactant (registered trademark) 650A (manufactured by Neos Co., Ltd.) were added. A clear hard coating solution was prepared.

<Preparation of Sample 221 Heat Shielding Film>
In the preparation of the heat ray shielding film of the sample 201 described above, the heat ray shielding layer coating solution A was changed to a clear hard coat solution, the thickness of the hard coat layer was adjusted to 2 μm, and the adhesive layer coating solution B was changed to the following: A heat ray shielding film of Sample 221 was produced in the same manner as Sample 201 except that the adhesive layer coating solution F was prepared by the method.

[Adhesive layer coating solution F]
As an adhesive, 100 parts by mass of N-2147 (solid content 35%, manufactured by Nippon Synthetic Chemical Industry) and 1.0 part by mass of an isocyanate curing agent coronate HL (solid content 75%, manufactured by Nippon Polyurethane Industry) were mixed. The adhesive layer coating solution F was prepared.

<Preparation of heat ray shielding film of sample 222>
In preparation of the heat ray shielding film of the sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 85%, and the adhesive layer coating solution B was changed to the adhesive layer coating solution F. A heat ray shielding film of Sample 222 was produced in the same manner as Sample 201.

<Preparation of heat ray shielding film of sample 223>
In preparation of the heat ray shielding film of the sample 201 described above, the thickness of the hard coat layer was adjusted so that the visible light transmittance was 30%, and the adhesive layer coating solution B was changed to the adhesive layer coating solution F. A heat ray shielding film of Sample 223 was produced in the same manner as Sample 201.

<Evaluation>
[Maximum transmittance at a wavelength of 350 to 400 nm]
Using a spectrophotometer U-4000 type (using an integrating sphere, manufactured by Hitachi, Ltd.) by a method according to JIS R3106-1998, the maximum transmittance of the heat ray shielding film of each sample in the wavelength region of 350 to 400 nm ( %).

[Minimum transmittance at 450 to 600 nm, difference in transmittance]
Using a spectrophotometer U-4000 type (using an integrating sphere, manufactured by Hitachi, Ltd.) by a method according to JIS R3106-1998, the minimum transmittance of the heat ray shielding film of each sample in the wavelength region of 450 to 600 nm ( %). Further, from the maximum value T% max (450 to 600) and the minimum value T% min (450 to 600) in the transmittance of the heat ray shielding film in the wavelength region of 450 to 600 nm, the heat ray in the wavelength region of 450 to 600 nm is obtained. The difference in transmittance of the shielding film was determined.

[Weather resistance test]
The adhesive layer side of the heat ray shielding films of Samples 201 to 223 was attached to blue glass having a thickness of 3 mm. Then, using a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd .; emitting light very close to sunlight) under the condition of 30 ° C. and 60% RH, a sample of xenon light having an intensity of 100 W / m ² is obtained from the blue glass side. The heat shielding films 201 to 223 were irradiated for 1000 hours. After this weather resistance test, the following crack and tape peel test were performed.

[crack]
With respect to the sample of the heat ray shielding film, 15 cm × 5 cm (75 cm ² ) was visually observed, and the number of cracks was counted. Based on the average value of 20 samples, the crack of the heat ray shielding film was evaluated according to the following criteria. In addition, if a crack is 4 or 3, it can be used practically without a problem.
4: 0 pieces 3: 1 to 10 pieces 2: 25 pieces 1:26 pieces or more

[Tape peeling test]
Using a 1506 mandrel bending tester (manufactured by Elcometer) with a mandrel having a diameter of 10 mm, the heat ray shielding layer was placed outside and the heat ray shielding film of each sample was bent. After that, according to the cross-cut method of JIS-K5600-5-6: 1999, a cross-cut with a one-blade razor blade is performed at an angle of 90 ° with respect to the surface on the outermost surface of the surface arranged outside. A 10 mm square grid was prepared. Cellophane tape No. manufactured by Nitto Denko Corporation 29 was affixed, the tape was peeled off, and the peeled state of the film was examined. F = (n ₁ / n) × 100 (%) was calculated, where n was the number of cross-cut cells and n ₁ was the number of cells remaining on the heat ray shielding film side after tape peeling. . Based on the average value of 20 samples, the tape peeling of the heat ray shielding film was evaluated according to the following criteria. In actual use, when F is 70% or more, it can be said that interlayer adhesion is secured.
4: F ≧ 90%
3: 90%> F ≧ 80%
2: 80%> F ≧ 70%
1: 70%> F

[Heat insulation performance (TSER: Total Solar Energy Rejection)]
Each sample of the heat ray shielding film was affixed to a 3 mm plate glass, and using a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4000 type), transmittance every 5 nm in the region of 300 nm to 2500 nm and The reflectance was measured. Next, using the solar transmittance T (DS) and solar reflectance R (DS) obtained by the method described in JIS S 3107: 2013, the heat shielding performance TSER was calculated by the following formula. The measurement was performed with the ultraviolet absorption layer side facing the detector side of the spectrophotometer.
TSER (%) = ((100−T (DS) −R (DS)) × 0.7143) + R (DS)

Table 2 shows the evaluation results for the heat ray shielding films of Samples 201 to 223.

As shown in Table 2, the samples 201 to 217 having a maximum transmittance at a wavelength of 350 to 400 nm of 3% or less and a minimum transmittance at a wavelength of 420 to 780 nm of 40% or more have a maximum wavelength of 350 to 400 nm. Compared with samples 218 to 223 having a transmittance of 3% or more, good results were obtained in the evaluation of cracks after the weather resistance test and tape peeling.
From this result, it is possible to improve the weather resistance of the heat ray shielding film by providing an ultraviolet absorbing layer having a high absorption of light having a wavelength of 350 to 400 nm which is a long wavelength side among ultraviolet light (maximum transmittance is 3% or less). I understand.

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, 20, 30 ... heat ray shielding film, 11 ... base material, 12 ... dielectric multilayer film, 13 ... ultraviolet absorption layer, 22 ... infrared absorption layer

Claims

A heat ray shielding film having a substrate, a heat ray shielding layer, and an ultraviolet ray absorbing layer,
The ultraviolet absorbing layer is provided outside the heat ray shielding layer;
The maximum transmittance of the ultraviolet absorbing layer at a wavelength of 350 to 400 nm is 40% or less,
The heat ray shielding film, wherein the heat ray shielding film has a minimum transmittance of 40% or more at a wavelength of 420 to 780 nm.
The heat ray shielding film according to claim 1, wherein the heat ray shielding film has a maximum transmittance of 3% or less at a wavelength of 350 to 400 nm.
The heat ray shielding film according to claim 1, wherein the heat ray shielding film has a minimum transmittance of 70% or more at a wavelength of 450 to 600 nm.
The heat ray shielding film according to claim 1, wherein the heat ray shielding film has a transmittance difference of 20% or less at a wavelength of 450 to 600 nm.
The heat ray shielding film according to claim 1, wherein the heat ray shielding layer contains one or more infrared absorbing materials selected from tungsten oxide and composite tungsten oxide.
The heat ray according to claim 1, wherein the heat ray shielding layer is a dielectric multilayer film in which a high refractive index layer containing a water-soluble polymer and titanium oxide and a low refractive index layer containing a water-soluble polymer are alternately laminated. Shielding film.
The heat ray shielding film according to claim 1, wherein the ultraviolet absorbing layer contains one or more ultraviolet absorbing materials selected from an indole compound, an azomethine compound, a coumarin compound, and a merocyanine compound.
The heat ray shielding film according to claim 7, wherein the ultraviolet absorbing layer contains one or more ultraviolet absorbing materials selected from a benzotriazole compound, a triazine compound, and a benzophenone compound.
The heat ray shielding film according to claim 7, wherein the ultraviolet absorbing layer contains 0.05 to 15% by mass of an ultraviolet absorbing material.
2. The heat ray shielding film according to claim 1, wherein the ultraviolet absorbing layer has a thickness of 1 μm to 30 μm.
The heat ray shielding film according to claim 1, wherein the ultraviolet ray absorbing layer is provided on both outer sides of the heat ray shielding layer.
The heat ray shielding film according to claim 1, wherein the ultraviolet absorbing layer contains an adhesive.
The heat ray shielding film according to claim 1, wherein the base material contains an ultraviolet absorbing material.