JP2020532451A - Window film - Google Patents

Abstract

This application relates to window film. The window film of the present application includes a translucent base material layer, an infrared reflective layer, an overcoating layer and a protective film that can be peeled off from the overcoating layer. The window film having the above structure can realize high functionality even after construction.

Description

Mutual Citation with Related Application This application claims the priority benefit based on Korean Patent Application No. 10-2017-0124723 filed on September 27, 2017, and is disclosed in the literature of the relevant Korean patent application. All content is incorporated herein by reference.

Technical field This application relates to window film. More specifically, the present application relates to a window film having an infrared reflection function.

Of the window films, the solar control film can be classified into an absorbent film and a reflective film by an infrared blocking method. Of these, the reflective solar control film generally has an alternating laminated structure of metal oxide layers and metal layers. When such window films adhere to the glass of buildings and vehicles, they can block heat or prevent heat loss and reduce energy consumption.

Since such a window film generally has a multi-layer structure, there are various causes such as the number of layers to be laminated, which causes a decrease in adhesive force and a peeling problem at an interlayer interface, a problem of a decrease in durability, and a film It has problems such as contamination and discoloration. In addition, the layer structure of the window film is often damaged in the process of transporting the window film for actual use. In particular, when the window film adheres to the glass of a building or a vehicle, a physical force is applied to the film, so that surface scratches and delamination are likely to occur. Such a problem becomes more noticeable when a window film is used for a large area glass.

One object of the present application is to provide a window film capable of stably exhibiting its original functions such as high heat insulation, high heat insulation, and high permeability even after construction.

All of the above and other purposes of this application may be resolved by this application described in detail below.

By way of example relating to this application, this application relates to window film. Specifically, the present application relates to a window film that is transparent to visible light but has a function of reflecting or blocking infrared rays.

Unless specifically defined otherwise in this application, "visible light" can mean, for example, light in the wavelength range of 380 nm to 780 nm, more specifically light in the wavelength range of 550 nm. Further, in the present application, "infrared ray" may mean light having a wavelength longer than that of visible light, and includes, for example, near infrared rays having a wavelength range of 780 nm to 2,500 nm and far infrared rays having a wavelength range of 2.5 μm to 25 μm. Can be used in the sense of

The window film of the present application may include a translucent base material layer, an infrared reflective layer, an overcoat layer and a protective film in this order.

The translucent base material layer has a structure that serves as a support for the window film, and may be a layer having a transmittance of 70% or more or 80% or more with respect to visible light. As long as the above-mentioned transmittance is satisfied, the material used for the translucent base material layer is not particularly limited. For example, known glass or resin film can be used.

In one example, the translucent base material layer may contain a flexible resin. For example, polyester resins such as polyethylene terephthalate resin, polyethylene naphthalate resin, and polybutylene terephthalate resin, acetate resins, polyether sulfone resins, polycarbonate resins, polyimide resins, polyolefin resins, (meth) acrylate resins, Polyvinyl chloride-based resin, polystyrene-based resin, polyvinyl alcohol-based resin, polyarylate-based resin, polyphenylene sulfide-based resin, and the like can be used for the translucent base material layer.

Although not particularly limited, the translucent base material layer may have a thickness of, for example, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more, and the upper limit thereof may be 200 μm or 150 μm.

The infrared reflective layer has a structure that reflects near infrared rays and far infrared rays, and can impart high heat shielding and high heat insulating functions to the window film. In this application, the infrared reflective layer is located on the translucent base material layer. In this application, the term "above" or "above" used in connection with the interlayer stacking position is used not only when one configuration is formed directly above another configuration, but also between these configurations. It means to include the case where the composition is intervened.

The infrared reflective layer includes a metal oxide layer and a metal layer.

In one example, the metal oxide layer can be located between the translucent substrate layer and the metal layer. The metal oxide layer located on one surface of the metal layer can impart wavelength selectivity to light, such as transmission to visible light and reflection to infrared light, to the window film.

The metal oxide layer includes antimony (Sb), barium (Ba), gallium (Ga), germanium (Ge), hafnium (Hf), indium (In), tantalum (La), magnesium (Mg), and selenium (Se). ), Silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), ittrium (Y), zinc (Zn) and / or tin (Sn) oxides may be contained. In one example, the metal oxide layer may be a layer composed of only the oxide of the metal, or may be a layer containing other components other than the listed components but containing the metal oxide as a main component. .. The "main component" may mean a case where any one of the components constituting a certain layer has a weight ratio of 85% or more in the corresponding layer.

Although not particularly limited, the metal oxide layer used in the present application may have a thickness in the range of 5 nm to 300 nm. Appropriate light transmittance and refractive index can be secured within the above-mentioned thickness range.

The method for forming the metal oxide layer is not particularly limited. Known dry or wet methods can be used to form the metal oxide layer. For example, a metal oxide layer can be formed by thin film deposition.

The metal layer is a layer that performs a main function related to the infrared ray blocking function of the film.

In one example, the metal layer comprises titanium (Ti), silver (Ag), platinum (Pt), gold (Au), copper (Cu), chromium (Cr), aluminum (Al), palladium (Pd) and / Or may contain nickel (Ni). The metal layer may be a layer containing only a metal, or a layer containing other components other than the listed components but containing the metal as a main component. When a metal component other than the listed metals, for example, tin (Sn) is contained, not only the optical properties of the film but also the heat shielding or heat insulating ability is lowered or the salt water resistance is lowered, and the durability of the film is deteriorated. It can get worse.

The method for forming the metal layer is not particularly limited. Known dry or wet methods can be used to form the metal layer. For example, a metal layer can be formed by thin film deposition.

In one example, the metal layer may include a plurality of lower metal layers. The lower metal layer may be configured to contain one or more of the same metal components as those listed above, and the specific metal components of each lower metal layer may be the same or different. When the metal layer includes a plurality of lower metal layers, the metal layer adjacent to the translucent base material layer among the plurality of metal layers can impart high heat shielding and high heat insulating functions to the window film, and other than that. The metal layer can contribute to improving the durability of the window film.

The overcoat layer is used in the window film to prevent damage to the infrared reflective layer. When considering the function of the window film, it is preferable that the overcoat layer has a property of having a high transmittance for visible light and a low absorption for infrared rays.

The overcoating layer can be selected within a range that does not impair the translucency of the window film. For example, the overcoat layer may contain a cured product of a composition comprising a monofunctional or polyfunctional photocurable organic compound and inorganic or organic particles.

The overcoat layer may have a thickness of 100 nm or less. If the thickness is exceeded, the transparency of the window film may be reduced, and the infrared reflection function of the window film may be reduced due to the absorption of infrared rays by the overcoating layer.

As an example, the window film of the present application may contain a release base material on one side opposite to one side of the translucent base material layer facing one side of the infrared reflective layer. The release base material may be attached to the translucent base material layer via an adhesive (layer). After removing the release film, the adhesive (layer) present between the release substrate and the translucent substrate can attach the window film to fittings such as glass. The release base material has a temporary protective function against an adhesive (layer) that adheres the window film to the fitting, and the type of the base material is not particularly limited as long as the function can be performed. ..

The window film of the present application may include a protective film located on the overcoat layer. The protective film can protect the window film from external forces and the external environment generated during handling, movement or construction of the window film. In addition, the protective film can be peeled off from one surface of the window film during construction without damaging the overcoating layer.

Specifically, the process of attaching the window film to a fitting such as glass for actual use is as follows. First, the surface of the glass to be attached is washed, and the window film is attached to the surface of the glass via the adhesive of the translucent base material layer from which the release base material has been removed. After that, using a tool such as a squeegee, water and air bubbles between the glass and the translucent base material layer are removed to bring the glass and the window film into close contact (adhesion). Finally, the protective film can be peeled off from the window film to finish the construction. The protective film can prevent breakage and scratches of the window film that may occur in the series of construction processes as described above, scratches on the surface of the overcoat layer and the infrared reflective layer that may occur in the adhesion process using a squeegee, and the like.

In the present application, the peeling force between the protective film and the adherend surface can be adjusted within a predetermined range. Specifically, the peeling force of the protective film measured at an angle of 180 ° with respect to the overcoat layer and a peeling speed of 150 mm / min (minutes) may be 8 gf / 25 mm to 60 gf / 25 mm. If the peeling force is less than 8 gf / 25 mm, the protective film may be peeled off during the handling of the window film, and the protective film is peeled off or wrinkled during the adhesion process using a squeegee, and the window film is damaged. There are times. If the peeling force exceeds 60 gf / 25 mm, the window film itself is peeled off from the glass in the process of peeling off the protective film to complete the construction, or the adhesive of the protective film remains in the overcoat layer. Sometimes.

In one example, the protective film may include a surface protective substrate and an adhesive layer. At this time, as the surface protecting base material, a polymer film known in the related technical field is used. For example, polyester films such as polyethylene terephthalate or polybutylene terephthalate, polytetrafluoroethylene films, polyethylene films, polypropylene films, polybutene films, polybutadiene films, poly (vinyl chloride) films or plastic films such as polyimide films can be used. These films may be used in a single layer, or may be laminated with each other and used in multiple layers. Although not particularly limited, the thickness of the surface protecting base material may be in the range of 10 μm to 100 μm.

The adhesive layer of the protective film can be formed from a predetermined composition, and the adhesive layer can impart the peeling force mentioned above to the protective film. The specific component of the composition is not particularly limited as long as it is a composition capable of forming a pressure-sensitive adhesive (PSA) having a property of being peelable after curing. For example, as the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, or the like can be used.

In one example, the composition may be an acrylic pressure-sensitive adhesive containing an acrylic polymer. In this case, the polymer may contain an alkyl (meth) acrylate monomer and a copolymerizable monomer having a crosslinkable functional group in a polymerized form, and the composition is the acrylic polymerization. A monofunctional or polyfunctional cross-linking agent may be contained outside the body.

In one example, the window film may further include a hard coating layer between the translucent substrate layer and the infrared reflective layer. More specifically, the window film may include a translucent base material layer, a hard coating layer, and a metal oxide layer of the first laminate described later in this order. The composition of the hard coating layer is not particularly limited as long as the translucency of the window film is not impaired, and for example, a resin containing organic or inorganic particles may be contained.

In one example, the infrared reflective layer may have a plurality of laminates including a metal oxide layer and / or a metal layer. More specifically, the infrared reflective layer of the present application may include a first laminated body and a second laminated body located on the first laminated body. The first laminated body may include a first metal oxide layer and a metal layer, and the second laminated body may include a metal oxide layer. The materials contained in each metal layer and metal oxide layer are as described above. At this time, the first laminated body can be located closer to the translucent base material layer than the second laminated body. The structure in which the metal layer and the metal oxide layer are laminated as described above can impart high heat shielding and high heat insulating functions to the window film.

In one example, the first laminated body may be a laminated body in which the metal layer is located on the first metal oxide layer. In this case, the window film may contain the first metal oxide layer and the metal layer in this order on the translucent base material layer.

In one example, the metal layer contained in the first laminated body may include two metal layers, that is, a first metal layer and a second metal layer. In the present application, the first metal layer may mean a metal layer located closer to the translucent base material layer side than the second metal layer. The second metal layer may be located on the first metal layer. Further, the metal components contained in the two metal layers may be the same or different from each other.

Further, in one example, one surface of the first metal layer and one surface of the second metal layer can be in direct contact with each other. In this case, the window film of the present application may have a structure including a first metal oxide layer, a first metal layer, and a second metal layer in this order on the translucent base material layer. In connection with such a laminated structure, for example, when only one metal layer is interposed between the metal oxide layer of the first laminated body and the metal oxide layer of the second laminated body, one of them is used. In the process of forming the metal oxide layer on the metal layer, the metal layer can be oxidized while being exposed to oxygen. Oxidation of such a metal layer causes the metal layer to lose its original function, and may cause a decrease in interfacial adhesive force between layers and poor durability such as discoloration. Therefore, the window film of the present application has a laminated structure in which the second metal layer is directly in contact with the first metal layer and the metal oxide layer constituting the second laminated body is located on the second metal layer. Can have. Through this, the window film can be provided with high heat insulation, high heat insulation and high durability at the same time.

In one example, the second metal layer may be configured so that the coefficient of thermal expansion (CTE) is different from that of the first metal layer. Specifically, the coefficient of thermal expansion of the second metal layer is smaller than the coefficient of thermal expansion of the first metal layer. In the present application, the "coefficient of thermal expansion of each layer" can be used in the same meaning as the coefficient of thermal expansion of the main component of the metal or metal oxide of each layer. The coefficient of thermal expansion can be measured by a thermomechanical analyzer (TMA). The difference in the magnitude of the coefficient of thermal expansion between the metal layers as described above can be controlled by appropriately selecting the metal component. For example, when the first metal layer contains silver (Ag), a metal having a coefficient of thermal expansion lower than that of silver (Ag), for example, titanium (Ti), can be used for the second metal layer. When the coefficient of thermal expansion between layers is adjusted as described above, the stress applied to the film due to the thermal expansion can be alleviated and the durability of the film can be improved.

The metal layer can have a thickness in the range of 1 nm to 50 nm. In one example, when the metal layer includes the first and second metal layers, the thickness of the first metal layer may be in the range of 5 nm to 30 nm, and the thickness of the second metal layer is 1 nm to 15 nm. May have a thickness of. When the above range is satisfied, the second metal layer can provide excellent interfacial adhesive strength by preventing deterioration of the first metal layer while not inhibiting the transmittance of the entire film.

In one example, the refractive index of the metal layer with respect to visible light may be in the range of 0.1 to 1.5. At this time, the refractive indexes of the lower metal layers may be the same as or different from each other. When the metal layer having the refractive index and the metal oxide layer having the constitution described later are used, a high transmittance for visible light and a low transmittance for infrared rays can be imparted to the window film. On the other hand, the refractive index can be changed depending on the vapor deposition thickness of the metal layer, the degree of crystallization at the time of forming the layer, and the like.

In one example, the second laminate may contain a plurality of metal oxide layers having different refractive indexes from each other. More specifically, the metal oxide layer having the highest visible light refractive index among the plurality of metal oxide layers contained in the second laminated body may be located adjacent to the first laminated body.

The number of metal oxide layers contained in the second laminate is not particularly limited. For example, the metal oxide layer is a second metal oxide layer and a third metal oxide layer, that is, two metal oxides. It may contain layers. In one example, the second metal oxide layer may mean a metal oxide layer located closer to the translucent base material layer side than the third metal oxide layer in the laminated structure of the window film. In this case, the window film of the present application may contain the first laminate, the second metal oxide layer, and the third metal oxide layer in this order on the translucent base material layer.

In one example, one surface of the second metal oxide layer and one surface of the third metal oxide layer may be in direct contact with each other. In this case, the types of the metal oxide contained in the second metal oxide layer and the type of the metal oxide contained in the third metal oxide layer may be different from each other. Alternatively, when the metal oxide layer contains two or more components, the second metal oxide layer and the third metal oxide layer may have different composition ratios from each other.

In one example, the metal oxide layer contained in the first laminate and the second laminate may have a visible light refractive index in the range of 1.5 to 3.0. At this time, the metal oxide layers may have different visible light refractive indexes. For example, among the metal oxide layers contained in the second laminated body, the refractive index of the second metal oxide layer adjacent to the metal layer of the first laminated body is the first metal oxide layer or the third metal oxide. It can have a value even greater than the refractive index of the layer. By adopting the above configuration, the light selection characteristics of the film for each wavelength can be improved and a highly translucent film can be provided.

In one example, the coefficients of thermal expansion of the metal layer and the metal oxide layer may be different from each other. The coefficient of thermal expansion of the metal oxide layer can be used in the same meaning as the coefficient of thermal expansion of the metal oxide component of the corresponding layer. For example, the metal layer contained in the first laminated body may have a higher coefficient of thermal expansion than the metal oxide layer contained in the first or second laminated body. Specifically, the second metal layer contained in the first laminated body may have a coefficient of thermal expansion larger than that of the metal oxide layer contained in the second laminated body. Even in such a case, the coefficient of thermal expansion of the second metal layer may have a value lower than the coefficient of thermal expansion of the first metal layer. When the coefficient of thermal expansion between adjacent layers is controlled as described above, the interfacial stress due to environmental changes such as external light and temperature can be alleviated and the durability of the film can be improved.

As an example, the window film of the present application may further contain one or more metal oxide layer and metal layer laminates between the first laminate and the second laminate. The added laminate may have a configuration in which one or more metal oxide layers and one or more metal layers are laminated on each other, similarly to the first laminate. The physical properties and composition of the metal layer or the metal oxide layer are the same as those mentioned above. Further, the refractive index of the metal oxide layer contained in the added laminate is that of the metal oxide layer formed so as to be closest to the first laminate among the metal oxide layers contained in the second laminate. It can be adjusted to have a value lower than the index of refraction.

The use of the window film of the present application is not particularly limited. For example, in another example relating to the present application, the present application may be fittings to which the window film is attached. "Joining" can mean various windows and doors installed in openings such as walls and doorways to block the inside of a building from the outside, and the specific configuration of fittings is particularly important. Not limited.

According to an example of the present application, it is possible to provide a window film capable of realizing high functionality without physical damage even after construction and a fitting including the window film.

Hereinafter, the window film of the present application will be described in detail through Examples and Comparative Examples. However, the scope of this application is not limited by the examples presented below.

Comparison of window film durability with protective film <Measurement and evaluation method>
* Peeling force: The adhesive layer of the protective film was reciprocated once with a load of 5 kg to adhere to the overcoat layer of the window film, and the specimen was cut into a width of 25 mm and a length of 150 mm. After 30 minutes, the load value (gf / 25 mm) when the protective film and the overcoat layer were peeled at 180 ° at a speed of 150 mm / min was measured using a universal tester (UTM).

* Scratch resistance: Evaluation proceeded according to the following procedure.
1) The release film is peeled off from the window film cut at 12 cm × 3 cm and adhered to the aluminum plate.
2) Using a rubbing tester, rub the window film in a 10 cm length range back and forth a predetermined number of times while applying a load of 1000 g with a double-sided canvas.
3) After the predetermined number of times has elapsed, the protective film is peeled off, and the presence or absence of scratches generated in the overcoat layer is confirmed.

* Salt water resistance (1): Evaluation proceeded according to the following procedure.
1) The window films of Examples and Comparative Examples are attached to 10 cm × 10 cm glass using a squeegee. In the case of the embodiment, the protective film is peeled off.
2) The above sample was immersed in a 10 wt% sodium chloride aqueous solution and stored in a dryer at 50 ° C. for 5 days, and then the appearance change was confirmed. (×: Appearance change (discolor) occurs due to scratches and damage generated while rubbing with squeegee, 〇: No appearance abnormality)

<Example 1>
A 2 μm-thick hard coating layer is formed on the PET base material among the laminates of the release film and the 50 μm-thick PET base material adhered via the pressure-sensitive adhesive, and the first metal oxide layer is formed on the PET base material. Was formed. The hard coating layer is formed by applying a composition containing Silicona inorganic particles to a polyfunctional (meth) acrylate monomer with a bar coater, drying at 80 ° C., and using an ultra-high pressure mercury lamp in a nitrogen atmosphere to achieve an integrated light amount of 600 mJ /. It is an organic-inorganic hybrid layer prepared by UV curing at cm ² . The first metal oxide layer was formed into a ZnO layer having a thickness of 15 nm under the conditions of 1.5 W / cm ² and 3 mTorr using a DC sputtering method. An Ag metal layer was deposited on the first metal oxide layer to a thickness of 14 nm using a DC sputtering method under the conditions of 1.5 W / cm ² and 3 mTorr. A Ti metal layer was deposited on the Ag layer to a thickness of 5 nm using a DC sputtering method under the conditions of 1.5 W / cm ² and 3 mTorr. Then, an NbOx layer as a second metal oxide layer was formed with a thickness of 10 nm under the conditions of 1.5 W / cm ² and 3 mTorr. Finally, an overcoat layer having a thickness of 50 nm was formed on the second metal oxide layer to produce an optical film. The overcoat layer is produced by adding 0.5 part by weight of a phosphate ester compound (MIWON, trade name: MIRAMER SC1400) to 100 parts by weight of a solid content containing a polyfunctional (meth) acrylate monomer and Silica inorganic particles. The overcoating solution was applied with a bar coater, dried at 80 ° C., and cured with ultraviolet rays at an integrated light amount of 400 mJ / cm ² using an ultrahigh pressure mercury lamp in a nitrogen atmosphere to prepare an organic-inorganic hybrid layer.

A protective film was inserted into the overcoat layer. The protective film is configured so that the peeling force against the overcoat layer satisfies the values shown in Table 1 below, and contains an acrylic PSA having a thickness of 18 μm and a protective base material (PET) having a thickness of 38 μm. There was.

The physical properties of the produced film were measured by the methods mentioned above, and the results are shown in Table 1.

<Example 2>
As shown in Table 1 below, the window film was produced by the same method except that the peeling force of the protective film was different from that of Example 1.

<Comparative example 1>
Window films were manufactured in the same manner, except that the protective film was omitted.

From Table 1 above, it can be seen that when the window film has a surface protective film having a predetermined peeling force, high functionality can be maintained even after construction.

It is judged that the function embodied by the window film having the following configuration is also maintained even after construction by applying the protective film having a predetermined peeling force as described above.

Comparison of window film functionality <Measurement and evaluation method>
* Heat transmission coefficient: Measured according to the KS L 2016 standard.
* Shielding coefficient: Measured according to the KS L 2016 standard.
* Transparency: Measured according to the KS L 2016 / KS L 2514 standard.
* Change in emissivity after immersion in salt water: Measured according to the KS L 2514 standard.
* Salt water resistance (2): After immersing the following produced film in a 10% NaCl solution for 7 days, the change in discoloration emissivity and / or the presence or absence of exfoliation was confirmed, and the degree was classified according to the following criteria. An increase in the emissivity value means that the metal layer or the like was damaged by salt water.

− When there is no discoloration and emissivity change: 〇 − When the discoloration is not large but the emissivity change is 0.2 or more: △
-If discoloration and peeling occur: ×

<Example 3>
A 2 μm-thick hard coating layer was formed on a 50 μm-thick PET substrate, and a first metal oxide layer was formed on the 2 μm-thick hard coating layer. The hard coating layer is formed by applying a composition containing Silicona inorganic particles to a polyfunctional (meth) acrylate monomer with a bar coater, drying the mixture at 80 ° C., and using an ultra-high pressure mercury lamp in a nitrogen atmosphere to achieve an integrated light intensity of 600 mJ /. It is an organic-inorganic hybrid layer prepared by UV curing at cm ² . The first metal oxide layer was formed into a ZnO layer having a thickness of 30 nm under the conditions of 1.5 W / cm ² and 3 mTorr using a DC sputtering method. An Ag metal layer was deposited on the first metal oxide layer to a thickness of 15 nm under the conditions of 1.5 W / cm ² and 3 mTorr using a DC sputtering method, and the metal layer was formed as a second metal layer. The Ti layer was formed with a thickness of 2 nm. The second metal layer was also deposited using a DC sputtering method under the conditions of 1.5 W / cm ² and 3 mTorr. Then, an NbOx layer as a second metal oxide layer was formed on the second metal layer with a thickness of 10 nm under the conditions of 1.5 W / cm ² and 3 mTorr, and the second metal oxidation was carried out through a DC sputtering method under the same conditions. A ZnO layer, which is a third metal oxide layer, was deposited on the material layer to a thickness of 20 nm. Finally, an overcoat layer having a thickness of 50 nm was formed on the second metal oxide layer to produce an optical film. The overcoat layer is a phosphate ester compound (MIWON, trade name) for improving the adhesion to the second metal oxide layer on 100 parts by weight of the solid content containing the polyfunctional (meth) acrylate monomer and Silica inorganic particles. : MIRAMER SC1400) The overcoating solution produced by adding 0.5 parts by weight was applied with a bar coater, dried at 80 ° C., and the integrated light amount was 400 mJ / cm ² using an ultrahigh pressure mercury lamp in a nitrogen atmosphere. It is an organic-inorganic hybrid layer prepared by curing with ultraviolet rays.

On the other hand, in the produced film, the visible light refractive index measured for each layer by an ellipsometer was 2.5 for the second metal oxide layer and 1.7 for the third metal oxide layer. On the other hand, it was confirmed that the first metal layer, the second metal layer, and the second metal oxide layer were formed so that the coefficient of thermal expansion decreased in this order.

The physical properties of the produced film were measured by the method mentioned above, and the results are shown in Table 2.

<Comparative example 2>
A window film was produced by the same method and configuration as in Example 3 except that the second metal layer was configured to contain Sn.

<Comparative example 3>
A window film was produced by the same method and configuration as in Example 3 except that the thickness of the second metal layer was formed to 0.5 nm.

<Comparative example 4>
A window film was produced by the same method and configuration as in Example 3 except that the laminated positions of the second metal oxide layer and the third metal oxide layer were changed from each other.

From Table 2 above, it can be seen that only the window film of Example 3 of the present application is excellent in durability-related factors such as heat transmission coefficient and shielding coefficient while ensuring visible light transmittance of 70% or more. Further, since the film of the present application has excellent interfacial adhesive strength, it can be confirmed that the change in emissivity is small and the salt water resistance is excellent. On the other hand, in Comparative Example 2 in which a metal different from that in the present application was used for the second metal layer, it can be confirmed that the permeability and the salt water resistance were all lowered. Further, in Comparative Example 3 in which the thickness of the second metal layer was selected to be very thin, it can be confirmed that there is no effect of improving salt resistance. On the other hand, Comparative Example 4 which does not satisfy the structure of the second laminated body of the present application also showed low transmittance.

Claims (13)

With a translucent substrate layer,
An infrared reflective layer located on the translucent base material layer and including a metal oxide layer and a metal layer,
The overcoating layer located on the infrared reflective layer and
A window film comprising a protective film located on the overcoat layer and capable of peeling from the overcoat layer. The window film according to claim 1, wherein the protective film has a peeling force of 8 gf / 25 mm to 60 gf / 25 mm measured at a 180 ° angle and a peeling speed of 150 mm / min with respect to the overcoat layer. .. The window film according to claim 2, wherein the protective film includes a surface protective base material and an adhesive layer. The metal oxide layer includes antimony (Sb), barium (Ba), gallium (Ga), germanium (Ge), hafnium (Hf), indium (In), lanthanum (La), magnesium (Mg), and selenium (Se). , Silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), ittrium (Y), zinc (Zn) and / or tin (Sn) oxides. The window film according to any one of 1 to 3. The metal layer is made of titanium (Ti), silver (Ag), platinum (Pt), gold (Au), copper (Cu), chromium (Cr), aluminum (Al), palladium (Pd) or nickel (Ni). The window film according to any one of claims 1 to 4, wherein the window film comprises. The window film according to any one of claims 1 to 5, further comprising a hard coating layer between the translucent base material layer and the infrared reflective layer. The infrared reflective layer is characterized by having a first laminated body including a first metal oxide layer and a metal layer; and a second laminated body including a metal oxide layer located on the first laminated body. , The window film according to any one of claims 1 to 6. The window film according to claim 7, further comprising a first metal oxide layer, a metal layer, and a second laminated body in this order. The window according to claim 8, wherein the metal layer includes a first metal layer and a second metal layer, and one surface of the first metal layer and one surface of the second metal layer are in direct contact with each other. the film. The first metal oxide layer, the first metal layer and the second metal layer are included in this order.
The window film according to claim 9, wherein the first metal layer has a thickness in the range of 5 nm to 30 nm, and the second metal layer has a thickness in the range of 1 nm to 15 nm. The window film according to claim 10, wherein the coefficient of thermal expansion of the second metal layer is smaller than the coefficient of thermal expansion of the first metal layer. The second laminated body includes a plurality of metal oxide layers having different refractive indexes from each other, and among the plurality of metal oxide layers contained in the second laminated body, the metal oxide layer having the highest visible light refractive index is the first. The window film according to claim 11, wherein the window film is located adjacent to one laminated body. A fitting comprising the window film according to any one of claims 1 to 12.