WO2019066290A1 - Window film - Google Patents

Abstract

The present application relates to a window film. The window film of the present application comprises: a light-transmitting base layer; an infrared-ray reflecting layer; an over-coating layer; and a protective film that can be peeled off from the over-coating layer. The window film comprising said features can achieve high performance even after being attached.

Description

Window film

Mutual citation with related application

This application claims the benefit of Korean Patent Application No. 10-2017-0124723, filed on September 27, 2017, the entire contents of which are incorporated herein by reference.

Technical field

The present application relates to window films. More specifically, the present application relates to a window film having an infrared reflection function.

In the window film, the solar control film can be distinguished as an absorbing film and a reflection film according to the infrared ray blocking method. Among them, the reflection type solar control film generally has an alternate laminated structure of a metal oxide layer and a metal layer. When such a window film is attached to a building or a vehicle glass, energy consumption can be reduced by blocking heat or preventing heat loss.

Since such a window film generally has a multilayer structure, it has a problem of deterioration in adhesion and delamination at the interlayer interface, durability deterioration, and contamination and discoloration of the film due to various reasons as many as the number of layers to be laminated. Furthermore, there are many cases where the layer structure of the window film is damaged during the transportation of the window film for practical use. Particularly, when a window film is attached to a building or a glass of a vehicle, a physical force is applied to the film, so that a surface scratch or delamination tends to occur. This problem is more noticeable when window films are used for large-area glass.

One object of the present invention is to provide a window film which can stably exhibit its inherent functions such as high-order heat, high thermal insulation, or high permeability even after construction.

The above and other objects of the present application can be all solved by the present application, which is described in detail below.

In one example of this application, the present application is directed to a window film. Specifically, the present application relates to a window film having transparency to visible light but performing a reflection or blocking function with respect to infrared light.

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

The window film of the present application may sequentially include a light-transmitting base layer, an infrared reflection layer, an overcoat layer, and a protective film.

The light-transmitting base layer may be a layer which serves as a support for a window film, and has a transmittance of visible light of 70% or more or 80% or more. If the transmittance is satisfied, the material used for the light-transmitting base layer is not particularly limited. For example, a known glass or resin film may be used.

In one example, the light-transmitting base layer may include a flexible resin. For example, a polyester resin such as a polyethylene terephthalate resin, a polyethylene naphthalate resin, and a polybutylene terephthalate resin, an acetate resin, a polyether sulfone resin, a polycarbonate resin, a polyimide resin, (Meth) acrylate resin, polyvinyl chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin or polyphenylene sulfide resin can be used for the light transmitting substrate layer.

The light transmitting base layer may have a thickness of, for example, not less than 5 占 퐉, not less than 10 占 퐉, not less than 20 占 퐉, or not less than 30 占 퐉, and the upper limit may be 200 占 퐉 or 150 占 퐉.

The infrared reflecting layer reflects near-infrared rays and far-infrared rays, and the window film can be given high-order heat and high heat-insulating function. In this application, the infrared reflecting layer is located on the light-transmitting base layer. In the present application, the term " on " or " on " used in connection with the interlayer deposition position includes not only the case where a certain constitution is formed directly on another constitution but also the case where a third constitution is interposed .

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

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

The metal oxide layer may be at least one selected from the group consisting of antimony (Sb), barium, gallium, germanium, hafnium, indium, lanthanum, magnesium, ), Silicon (Si), tantalum (Ta), titanium (Ti), vanadium (V), yttrium (Y), zinc (Zn), and / or tin (Sn). In one example, the metal oxide layer may be a layer consisting only of the oxide of the metal, or a layer containing a component other than the listed components but containing a metal oxide as a main component. The main component may mean a case where the weight ratio of any one component constituting a layer to the layer is 85% or more.

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. It is possible to secure an appropriate light transmittance and refractive index within the above-mentioned thickness range.

The method of forming the metal oxide layer is not particularly limited. A known dry or wet method can be used to form the metal oxide layer. For example, a metal oxide layer can be formed by vapor deposition.

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

In one example, the metal layer is formed of a material selected from the group consisting of Ti, Ag, Pt, Au, Cu, Cr, Al, Pd, and / Nickel (Ni). The metal layer may be a layer containing only a metal or may be a layer containing a component other than the listed components but containing the metal as a main component. When a metal component other than the above-listed metals, for example, tin (sn) is included, the durability of the film may deteriorate, such as the optical properties of the film,

The method for forming the metal layer is not particularly limited. Known dry or wet methods can be used for metal layer formation. For example, a metal layer may be formed by vapor deposition.

In one example, the metal layer may comprise a plurality of lower metal layers. The lower metal layer may be configured to include at least one 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 light-transmitting base layer among the plurality of metal layers can impart higher-order heat and a high thermal insulating function to the window film, and the other metal layer can contribute to improvement in durability of the window film have.

The overcoat layer is used in window films to prevent damage to the infrared reflective layer. Considering the function of the window film, it is preferable that the overcoat layer has a high transmittance to visible light and a low absorbency to infrared rays.

The overcoat layer may be selected within a range that does not impair the light transmittance of the window film. For example, the overcoat layer may comprise a cured product of a composition comprising a monofunctional organic compound and a monofunctional or multifunctional organic and inorganic or organic particles.

The overcoat layer may have a thickness of 100 nm or less. If the thickness is exceeded, the transmissivity of the window film may be lowered, and the infrared ray reflection function of the window film may be deteriorated due to the infrared absorption of the overcoat layer.

In one example, the window film of the present application may include a release substrate on the opposite surface of one side of the translucent substrate layer facing one surface of the infrared reflective layer. The release type substrate may be attached to the light-transmitting substrate layer via a pressure-sensitive adhesive (layer). After removing the release film, the pressure sensitive adhesive (layer) present between the release substrate and the translucent substrate can attach the window film to a window such as a glass. The mold release substrate performs a temporal protection function for a pressure-sensitive adhesive (layer) for attaching the window film to the window, and the type of the substrate 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 an external force or an external environment generated during handling, movement, or construction of the widow film. And, the protective film can be peeled from one surface of the window film without damaging the overcoat layer at the time of construction.

Specifically, the process of attaching a window film to a window such as a glass for actual use is as follows. First, the surface of the glass to be adhered is cleaned, and the window film is attached to the surface of the glass through the pressure-sensitive adhesive of the light-transmitting base layer from which the release substrate has been removed. Thereafter, water or bubbles between the glass and the light-transmitting base layer are removed by using a tool such as squeegee to adhere (adhere) the glass and the window film. Finally, the protective film can be peeled off from the window film to complete the construction. The protective film can prevent the overcoat layer or the surface of the infrared ray reflective layer from scratching, which may occur during the bending process of the window film, which may occur during a series of construction processes as described above, or by the squeegee.

In the present application, the peeling force between the protective film and the adherend can be adjusted to a predetermined range. Specifically, the peel strength of the protective film measured at an angle of 180 ° to the overcoat layer and a peel rate of 150 mm / min (min) 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 peel off during handling of the window film, and the protective film may be peeled or wrinkled in the process of squeegee adhesion to damage the window film. If the peel force exceeds 60 gf / 25 mm, the window film itself may peel off from the glass or the adhesive of the protective film may remain on the overcoat layer in the process of peeling off the protective film for completion of the construction.

In one example, the protective film may comprise a surface protective substrate and an adhesive layer. At this time, a polymer film known in the related art may be used as the surface protective substrate. For example, a polyester film such as polyethylene terephthalate or polybutylene terephthalate, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a poly (vinyl chloride) film or a polyimide film May be used. These films may be used as a single layer, or may be laminated to each other and used in multiple layers. Though not particularly limited, the thickness of the surface protective substrate may range from 10 m to 100 m.

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

In one example, the composition may be an acrylic adhesive comprising an acrylic polymer. In this case, the polymer may include an alkyl (meth) acrylate monomer and a copolymerizable monomer having a crosslinkable functional group in a polymerized form, and the composition may include a monofunctional or multifunctional crosslinking agent in addition to the acrylic polymer .

In one example, the window film may further comprise a hard coat layer between the light-transmitting substrate layer and the infrared reflective layer. More specifically, the window film may sequentially include a light-transmitting base layer, a hard coat layer, and a metal oxide layer of the first laminate described below. The constitution of the hard coat layer is not particularly limited so long as it does not impair the light transmittance of the window film. For example, the hard coat layer may include a resin including organic or inorganic particles.

In one example, the infrared reflecting layer may have a plurality of stacked layers including a metal oxide layer and / or a metal layer. More specifically, the infrared reflecting layer of the present application may include a first laminate and a second laminate positioned on the first laminate. The first laminate may include a first metal oxide layer and a metal layer, and the second laminate may include a metal oxide layer. The materials each of the metal layer and the metal oxide layer are the same as described above. At this time, the first laminate may be positioned closer to the light-transmitting base layer than the second laminate. The structure in which the metal layer and the metal oxide layer are stacked as described above can impart a high degree of heat and a high heat insulating function to the window film.

In one example, the first laminate may be a laminate where the metal layer is located on the first metal oxide layer. In this case, the window film may sequentially include the first metal oxide layer and the metal layer on the light-transmitting base layer.

In one example, the metal layer included in the first laminate may include two metal layers, i.e., 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 light-transmitting base layer side than the second metal layer. The second metal layer may be located on the first metal layer. The metal components included in the two metal layers may be the same or different.

In another example, one surface of the first metal layer and one surface of the second metal layer may be in intimate contact with each other. In this case, the window film of the present application may have a structure including the first metal oxide layer, the first metal layer, and the second metal layer sequentially on the light-transmitting base layer. Regarding such a laminated structure, for example, if only one metal layer is interposed between the metal oxide layer of the first laminate and the metal oxide layer of the second laminate, a metal oxide layer is formed on any one of the metal layers The metal layer may be oxidized while being exposed to oxygen. Oxidation of such a metal layer loses its original function of the metal layer and may cause a decrease in interlayer interfacial adhesion and a durability defect such as discoloration. Therefore, the window film of the present application may have a laminated structure in which the second metal layer directly contacts the first metal layer, and the metal oxide layer constituting the second laminate is located on the second metal layer. This makes it possible to simultaneously impart high-order heat, high thermal insulation and high durability to the window film.

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

The metal layer may have a thickness ranging from 1 nm to 50 nm. In one example, when the metal layer comprises a first and a second metal layer, the first metal layer may have a thickness in the range of 5 nm to 30 nm, and the second metal layer may have a thickness of 1 nm to 15 nm have. When the above range is satisfied, the second metal layer can prevent the deterioration of the first metal layer and provide a good interlaminar bond strength without interfering with the transmittance of the entire film.

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

In one example, the second laminate may comprise a plurality of metal oxide layers having different refractive indices. More specifically, the metal oxide layer having the largest visible light refractive index among the plurality of metal oxide layers included in the second laminate may be positioned adjacent to the first laminate.

The number of metal oxide layers included in the second laminate is not particularly limited. For example, the metal oxide layer may include a second metal oxide layer and a third metal oxide layer, that is, two metal oxide layers . In one example, the second metal oxide layer may mean a metal oxide layer located closer to the side of the light-transmitting substrate layer 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 sequentially include the first laminate, the second metal oxide layer and the third metal oxide layer on the light-transmitting base layer.

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

In one example, the metal oxide layer included in the first laminate and the second laminate may have a visible light refractive index ranging from 1.5 to 3.0. At this time, the metal oxide layer may have different visible light refractive indexes. For example, when the refractive index of the second metal oxide layer adjacent to the metal layer of the first laminate among the metal oxide layers included in the second laminate is larger than the refractive index of the first metal oxide layer or the third metal oxide layer Lt; / RTI > By adopting such a constitution as above, the light selection characteristic of each wavelength of the film can be improved and a highly transmissive film can be provided.

In one example, the thermal expansion coefficients of the metal layer and the metal oxide layer may be different from each other. The thermal expansion coefficient of the metal oxide layer can be used in the same sense as the thermal expansion coefficient of the metal oxide component of the layer. For example, the metal layer included in the first laminate may have a higher thermal expansion coefficient than the metal oxide layer included in the first or second laminate. Specifically, the second metal layer included in the first laminate may have a thermal expansion coefficient larger than that of the metal oxide layer included in the second laminate. Even in this case, the coefficient of thermal expansion of the second metal layer may have a lower value than that of the first metal layer. As described above, when the adjacent interlayer thermal expansion coefficient is controlled, the interfacial stress due to environmental changes such as external light, temperature, etc. is relaxed and the durability of the film can be improved.

In one example, the window film of the present application may further include at least one laminate of a metal oxide layer and a metal layer between the first laminate and the second laminate. The additional laminate may have a configuration in which at least one metal oxide layer and at least one metal layer are laminated to each other like the first laminate. The physical properties and composition of the metal layer or the metal oxide layer are the same as those mentioned above. The refractive index of the metal oxide layer included in the laminate to be added may be adjusted to have a refractive index lower than the refractive index of the metal oxide layer provided closest to the first laminate among the metal oxide layers included in the second laminate .

The application of the present application window film is not particularly limited. For example, in another example of the present application, the present application may be fittings to which the window film is attached. The window can mean various windows or doors installed in openings such as a wall or an entrance to block the inside of the building from the outside, and the specific configuration of the window is not particularly limited.

According to an example of the present application, a window film and a window including the window film can be provided, which can realize a high function without physical damage even after construction.

Hereinafter, the pressure-sensitive adhesive polarizer of the present application will be described in detail through examples and comparative examples. However, the scope of the present application is not limited by the following examples.

Comparison of durability of window film according to protective film

<Measurement and Evaluation Method>

* Peeling force : The adhesive layer of the protective film was bonded to the overcoat layer of the window film one time by reciprocation with a load of 5 kg, 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 off at 180 ° at a rate of 150 mm / min using an universal testing machine (UTM) was measured.

* Scratch resistance: The evaluation was carried out in the following order.

1) The release film is peeled off from the window film cut to 12 cm x 3 cm and attached to the aluminum plate.

2) Using a rubbing tester, apply a 1000 g load to a double sided canvas and rub the window film a predetermined number of times over a 10 cm length range.

3) After the lapse of a predetermined number of times, the protective film is peeled off and the presence or absence of scratches on the overcoat layer is checked.

* Saltwater (1): The evaluation was carried out in the following order.

1) A window film of Examples and Comparative Examples was attached to a 10 cm x 10 cm glass using a squeegee. In the case of the embodiment, the protective film is peeled off.

2) The above samples were immersed in a 10% by weight aqueous solution of sodium chloride and stored in a dryer at 50 ° C for 5 days. X: appearance of discolor due to scratches and damage caused by rubbing with a squeegee, O: none)

Example  One

A hard coat layer having a thickness of 2 占 퐉 was formed on a PET substrate of a release film adhered via a pressure-sensitive adhesive and a 50 占 퐉 thick PET-based laminate, and a first metal oxide layer was formed thereon. The hard coat layer is a polyfunctional (meth) acrylate and then a monomer composition containing Silica inorganic particles in a coating with a bar coater, dried with a 80 ℃, and radiation-curing by use of ultra-high pressure mercury lamp, the accumulated light quantity 600 mJ / cm ² in a nitrogen atmosphere Inorganic hybride layer provided on the substrate. The first metal oxide layer was formed with a 15 nm thick ZnO layer at 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 at a thickness of 14 nm under the conditions of 1.5 W / cm ² and 3 mTorr by a DC sputtering method. On the Ag layer, a Ti metal layer was deposited to a thickness of 5 nm under a condition of 1.5 W / cm ² and 3 mTorr using a DC sputtering method. Thereafter, a NbO x layer as a second metal oxide layer was formed to a thickness of 10 nm under the conditions of 1.5 W / cm ² and 3 mTorr. Finally, an optical film was prepared by forming an overcoat layer having a thickness of 50 nm on the second metal oxide layer. The overcoat layer was prepared by coating an overcoat solution prepared by adding 0.5 part by weight of a phosphate ester compound (trade name: MIRAMER SC1400) to 100 parts by weight of a solid component containing a polyfunctional (meth) acrylate monomer and silica inorganic particles, Followed by drying at 80 占 폚 and ultraviolet ray curing at an accumulated light quantity of 400 mJ / cm ² using an ultrahigh pressure mercury lamp in a nitrogen atmosphere.

A protective film was laminated on the overcoat layer. The protective film was constructed such that the peel force against the overcoat layer satisfied the values shown in Table 1 below, and an acrylic PSA having a thickness of 18 탆 and a protective substrate (PET) having a thickness of 38 탆 were used.

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

Example  2

A window film was prepared in the same manner as in Example 1, except that the peel strength of the protective film was changed as shown in Table 1 below.

Comparative Example  One

A window film was prepared in the same manner in the same manner except that the protective film was omitted.

	Peeling force of protective film	My scratch test	Saltwater
Example 1	10 gf / 25 mm	No scratch after 500 round trips	○
Example 2	50 gf / 25 mm	No scratch after 500 round trips	○
Comparative Example 1	-	Scratch observed after 200 round trips	X

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

The function to be realized by the window film having the constitution described below can also be maintained after the application by applying the protective film having the predetermined peeling force as described above.

window  Functional comparison of film

<Measurement and Evaluation Method>

* Thermal Permeability: Measured according to KS L 2016 standard.

* Shielding Coefficient: Measured according to KS L 2016 standard.

Transmittance: Measured according to KS L 2016 / KS L 2514 standard.

* Emissivity change after salt water immersion: measured according to KS L 2514 standard.

Salt resistance (2): After immersing the film prepared as described below in a 10% NaCl solution for 7 days, it was confirmed whether or not a change in color change emissivity and / or peeling occurred, and the degree was classified according to the following criteria. The increase in the emissivity value means that the metal layer or the like is damaged by the brine.

- without discoloration and emissivity changes: o

- When the discoloration is not large but the emissivity change is more than 0.2:

- In case of discoloration and peeling: X

Example 3

On the 50 탆 thick PET substrate, a hard coat layer having a thickness of 2 탆 was formed, and a first metal oxide layer was formed thereon. The hard coat layer is a polyfunctional (meth) acrylate and then a monomer composition containing Silica inorganic particles in a coating with a bar coater, dried with a 80 ℃, and radiation-curing by use of ultra-high pressure mercury lamp, the accumulated light quantity 600 mJ / cm ² in a nitrogen atmosphere Inorganic hybride layer provided on the substrate. The metal oxide layer was formed with a 30 nm thick ZnO layer at 1.5 W / cm ² and 3 mTorr using a DC sputtering method. An Ag metal layer was deposited to a thickness of 15 nm on the first metal oxide layer under a condition of 1.5 W / cm ² and 3 mTorr using a DC sputtering method, and a Ti layer was formed as a second metal layer on the metal layer to a thickness of 2 nm . The second metal layer was also deposited using DC sputtering under the conditions of 1.5 W / cm ² and 3 mTorr. Thereafter, a NbOx layer as a second metal oxide layer was formed on the second metal layer to a thickness of 10 nm under the conditions of 1.5 W / cm ² and 3 mTorr, and the NbO x layer was formed on the second metal oxide layer A ZnO layer as a third metal oxide layer was deposited to a thickness of 20 nm. Finally, an optical film was prepared by forming an overcoat layer having a thickness of 50 nm on the second metal oxide layer. The overcoat layer was prepared by adding 0.5 part by weight of a phosphoric acid ester compound (Miwon, product name: MIRAMER SC1400) to 100 parts by weight of a solid component containing a polyfunctional (meth) acrylate monomer and silica inorganic particles to improve adhesion to the second metal oxide layer Inorganic hybrid layer prepared by applying the coated overcoat solution with a bar coater, drying at 80 DEG C, and ultraviolet curing using an ultrahigh pressure mercury lamp under an atmosphere of nitrogen at an accumulated light quantity of 400 mJ / cm &lt; ² &gt;.

On the other hand, in the produced film, the second metal oxide layer was 2.5 and the third metal oxide layer was 1.7, as measured by Ellipsometer. On the other hand, it was confirmed that the first metal layer, the second metal layer, and the second metal oxide layer were arranged so as to have a lower thermal expansion coefficient.

The properties of the films thus prepared were measured by the above-mentioned methods, and the results are shown in Table 2. &lt; tb &gt; &lt; TABLE &gt;

Comparative Example  2

A window film was prepared in the same manner and in the same manner as in Example 3, except that the second metal layer was made to contain Sn.

Comparative Example  3

A window film was produced in the same manner as in Example 3 except that the thickness of the second metal layer was 0.5 nm.

Comparative Example  4

A window film was produced in the same manner as in Example 3 except that the lamination positions of the second metal oxide layer and the third metal oxide layer were changed from each other.

	Thermal Permeability (W / cm 2 · K)	Shielding coefficient	Visible light transmittance (%)	Emissivity change after salt water immersion	Saltwater
Example 3	3.40	0.58	72.5	0	○
Comparative Example 2	3.65	0.50	59.5	1.3	△
Comparative Example 3	3.41	0.57	71.8	82.2	X
Comparative Example 4	3.62	0.59	69.0	0.8	△

From Table 2, it can be seen that the durability-related factors such as the heat conduction rate and the shielding coefficient are excellent, while the visible light transmittance of the window film of Embodiment 3 is merely 70% or more. Further, since the film of the present application has excellent interfacial adhesion, it can be confirmed that the change of the emissivity is small and the water resistance is excellent. On the other hand, in Comparative Example 2 in which a metal different from the present application was used for the second metal layer, it was confirmed that the permeability and the salt resistance were both lowered. Further, in Comparative Example 3 in which the thickness of the second metal layer was selected to be too thin, it was confirmed that the effect of improving the salt water resistance was not exhibited. On the other hand, Comparative Example 4, which does not satisfy the composition of the second laminate of the present application, also shows low transmittance.

Claims (13)

1. A light-transmitting base layer; An infrared reflecting layer located on the transparent transparent base material layer and including a metal oxide layer and a metal layer; An overcoat layer positioned on the infrared reflective layer; And a protective film disposed on the overcoat layer, the protective film being peelable from the overcoat layer.
2. The window film according to claim 1, wherein the protective film has a peel force of 8 gf / 25 mm to 60 gf / 25 mm measured at an angle of 180 ° with respect to the overcoat layer and a peeling speed of 150 mm / min.
3. The window film according to claim 2, wherein the protective film comprises a surface protective substrate and an adhesive layer.
4. The method of claim 1, wherein the metal oxide layer is formed of at least one selected from the group consisting of antimony (Sb), barium, gallium, germanium, hafnium, indium, lanthanum, (Si), tantalum (Ta), titanium (Ti), vanadium (V), yttrium (Y), zinc (Zn), or tin (Sn).
5. The method of claim 1, wherein the metal layer is formed of one selected from the group consisting of Ti, Ag, Pt, Au, Cu, Cr, Al, Pd, (Ni).
6. The window film according to claim 1, further comprising a hard coating layer between the transparent substrate layer and the infrared reflective layer.
7. The infrared ray sensor according to claim 1,

   A first laminate including a first metal oxide layer and a metal layer; And a second laminate positioned on the first laminate, the second laminate comprising a metal oxide layer.
8. 8. The window film of claim 7, comprising a first metal oxide layer, a metal layer, and a second laminate sequentially.
9. 9. The window film of claim 8, wherein the metal layer comprises a first metal layer and a second metal layer, wherein one surface of the first metal layer and one surface of the second metal layer are in direct contact with each other.
10. 10. The method of claim 9, further comprising sequentially depositing a first metal oxide layer, a first metal layer, and a second metal layer,

    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.
11. The window film of claim 10, wherein a coefficient of thermal expansion of the second metal layer is smaller than a coefficient of thermal expansion of the first metal layer.
12. The method according to claim 11, wherein the second laminate comprises a plurality of metal oxide layers having different refractive indexes, and the metal oxide layer having the largest visible light refractive index among the plurality of metal oxide layers included in the second laminate is a first A window film positioned adjacent to the laminate.
13. A window comprising a window film according to any one of the preceding claims.