JP2016212275A - Low thermal conductivity film - Google Patents

Abstract

A low thermal flow-through film with improved durability.
A film substrate having first and second surfaces; and at least a first layer and a second layer disposed on the first surface of the film substrate; The layer is closer to the film substrate than the second layer, and has a refractive index higher than the refractive index of the second layer with respect to light having a wavelength of 550 nm, and the refractive index A transparent conductive layer mainly composed of indium tin oxide (ITO) disposed on the adjustment film; an upper layer disposed on the transparent conductive layer and having a refractive index of 1.55 or less with respect to light having a wavelength of 550 nm; A low thermal flow-through film.
[Selection] Figure 1

Description

  The present invention relates to a low heat-through film.

  2. Description of the Related Art Conventionally, it is known that a low heat-through film is attached to the inside of a glass member such as a building or a vehicle, thereby suppressing a temperature drop in the room (inside the vehicle) and enhancing the heat insulating effect in the room (in the vehicle).

  A general low heat-throughflow film is configured by arranging a multilayer film including a thin silver layer on a resin film base material on the indoor (inside of the vehicle) surface side of the film base material. Since this thin silver layer functions as an infrared reflection functional layer that reflects infrared rays or the like in the room (inside the vehicle), the above-described heat insulation effect can be obtained when a low heat-through film is used.

Japanese Patent No. 5336739

  However, the conventional low heat-throughflow film has a problem that it does not show very good durability because it has a silver layer having problems in terms of moisture resistance, scratch resistance, and fingerprint resistance. For example, conventional low heat-throughflow films tend to deteriorate easily, such as reacting with moisture in the environment or causing discoloration after touching with a finger.

  For this reason, there is a demand for a low heat-through film having better durability.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a low heat-through film having improved durability as compared with the conventional art.

In the present invention,
A film substrate having first and second surfaces;
Disposed on the first surface of the film substrate and having at least a first layer and a second layer, the first layer being closer to the film substrate than the second layer, and having a wavelength A refractive index adjusting film having a refractive index higher than that of the second layer with respect to 550 nm light;
A transparent conductive layer mainly composed of indium tin oxide (ITO) disposed on the refractive index adjusting film;
An upper layer disposed on the transparent conductive layer and having a refractive index of 1.55 or less for light having a wavelength of 550 nm;
A low thermal flow-through film is provided.

  The present invention can provide a low heat-throughflow film having improved durability as compared with the prior art.

It is sectional drawing which showed typically the structure of the low heat-throughflow film by one Embodiment of this invention. It is the figure which showed typically an example of the flow of the manufacturing method of the low heat-throughflow film by one Embodiment of this invention. In sample 1, it is the figure which plotted the reflective color which arises when light is irradiated at each incident angle on the color coordinate of color space. In sample 2, it is the figure which plotted the reflected color which arises when light is irradiated at each incident angle on the color coordinate of color space. In sample 3, it is the figure which plotted the reflective color produced when light was irradiated at each incident angle on the color coordinate of color space. In sample 4, it is the figure which plotted the reflective color produced when light was irradiated at each incident angle on the color coordinate of color space. In sample 7, it is the figure which plotted the reflective color produced when light was irradiated at each incident angle on the color coordinate of color space. In sample 8, it is the figure which plotted the reflective color produced when light was irradiated at each incident angle on the color coordinate of color space.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Low thermal once-through film according to one embodiment of the present invention)
In FIG. 1, the cross section of the low thermal-flow-through film by one Embodiment of this invention is shown typically.

  As shown in FIG. 1, the low heat-throughflow film 100 includes a film substrate 110, a refractive index adjusting film 120, a transparent conductive layer 130, and an upper layer 150.

  The film substrate 110 has a first surface 112 and a second surface 114.

  The refractive index adjustment film 120 is installed on the first surface 112 of the film base 110. The refractive index adjusting film 120 has a role of adjusting the angle dependency of the reflected color of the low heat-throughflow film 100 by controlling the refractive index of one or more layers included in the refractive index adjusting film 120.

  In the example of FIG. 1, the refractive index adjustment film 120 is composed of two layers, a first layer 122 and a second layer 126, from the side close to the film substrate 110. In this configuration, the first layer 122 has a higher refractive index than the second layer 126 with respect to light having a wavelength of 550 nm.

  However, this is merely an example, and the refractive index adjustment film 120 may be composed of a single layer or three or more layers.

  The transparent conductive layer 130 is disposed on the refractive index adjusting film 120 as a layer having a heat ray reflecting function. The transparent conductive layer 130 is made of a material mainly composed of indium tin oxide (ITO). Here, in the present application, “consisting mainly of the A material” means that the member contains 50 wt% or more of the A material. Further, the “refractive index” described in the present invention means a refractive index when a refractive index is measured by processing into a single layer on a substrate under the same conditions as when the film described in the present invention is processed during lamination. .

  The refractive index of the transparent conductive layer 130 with respect to light having a wavelength of 550 nm is, for example, in the range of 1.6 to 2.5.

  The upper layer 150 is disposed on the transparent conductive layer 130. Here, in this application, the “upper part” of the “upper layer” means that the film base 110 is disposed on the side farther from the transparent conductive layer 130. Therefore, the expression “upper layer” does not necessarily mean that the upper layer 150 is the uppermost layer.

  The upper layer 150 has a role of protecting the transparent conductive layer 130 and enhancing the durability of the low heat-throughflow film 100.

  Although not shown in FIG. 1, a peeling prevention layer may be provided between the transparent conductive layer 130 and the upper layer 150. When the peeling prevention layer is provided, the possibility that both peel at the interface between the transparent conductive layer 130 and the upper layer 150 can be reduced. However, the installation of the peeling prevention layer 140 is arbitrary, and the peeling prevention layer 140 may be omitted.

  The low heat-throughflow film 100 having such a configuration exhibits good heat insulating properties. For example, the vertical emissivity of the low thermal flow-through film 100 is 0.3 or less. Therefore, when the low heat-throughflow film 100 is applied to, for example, a window glass of a building and a glass member of a vehicle (hereinafter collectively referred to as “glass member”) or the like, the heat in the room (inside the vehicle) is exposed to the outside. Dissipation can be significantly suppressed.

  Further, in the low heat-throughflow film 100, the transparent conductive layer 130 mainly composed of ITO is used as the infrared reflection functional layer instead of the silver layer. For this reason, this low heat-throughflow film 100 has relatively good durability. For example, the low heat-throughflow film 100 significantly suppresses the conventional problem that it easily deteriorates by reacting with moisture in the environment or causing discoloration due to oils and fats when touched with a finger. can do.

  Moreover, in the conventional low heat-throughflow film, the reflected color of the low heat-throughflow film may change depending on the viewing direction. Such angle dependency of the reflected color may give a viewer a sense of incongruity when he / she looks at the glass member on which the low heat-through film is attached.

  However, the low heat-throughflow film 100 according to the embodiment of the present invention includes the refractive index adjusting film 120. In the refractive index adjusting film 120, the refractive index of each layer constituting the refractive index adjusting film 120 is appropriately adjusted. For example, as described above, the refractive index adjusting film 120 includes the first layer 122 having a relatively high refractive index with respect to light having a wavelength of 550 nm, and the second layer 126 having a relatively low refractive index. Consists of.

  Moreover, in this low heat-throughflow film 100, each layer from the refractive index adjustment film | membrane 120 to the upper layer 150 is comprised so that the angle dependence of a reflected color may not be adversely affected. For example, the upper layer 150 is made of a material that has a refractive index of 1.55 or less with respect to light having a wavelength of 550 nm.

  With such a configuration, the present low heat-throughflow film 100 can significantly suppress the angle dependency of the reflected color.

(Members constituting the low heat-throughflow film according to one embodiment of the present invention)
Next, each member which comprises the low heat-throughflow film by one Embodiment of this invention is demonstrated in detail. In the following description, the reference numerals used in FIG. 1 are used for clarity when representing each member (layer).

(Film substrate 110)
The film substrate 110 of the low heat-throughflow film 100 has a role as a substrate that supports other layers.

  The film base 110 is made of a transparent resin, for example. Examples of the transparent resin include polyethylene terephthalate (PET), polyethylene naphthalate, polymethacrylate, and polycarbonate.

  The thickness of the film substrate 110 may be, for example, in the range of 5 μm to 200 μm. By setting the thickness of the film base 110 to 200 μm or less, the entire thickness of the low heat-throughflow film 100 can be suppressed. Moreover, each layer laminated | stacked on the upper part can be supported by the thickness of the film base material 110 being 5 micrometers or more.

  The thickness of the film substrate 110 is preferably in the range of 30 μm to 150 μm, and more preferably in the range of 40 μm to 120 μm.

(Refractive index adjusting film 120)
The refractive index adjusting film 120 has a role of adjusting the angle dependency of the reflected color of the low thermal flow-through film 100.

  As described above, the refractive index adjustment film 120 may be composed of a plurality of layers including at least the first layer 122 and the second layer 126.

  In this case, the first layer 122 closer to the film substrate 110 preferably has a higher refractive index than the second layer 126 with respect to light having a wavelength of 550 nm. For example, the first layer 122 has a refractive index in the range of 1.6 to 2.5 with respect to light having a wavelength of 550 nm. The refractive index is preferably in the range of 1.7 to 2.4, and more preferably in the range of 1.7 to 2.2.

  On the other hand, the second layer 126 has a refractive index of 1.6 or less with respect to light having a wavelength of 550 nm, for example. The refractive index is preferably 1.55 or less.

  The first layer 122 is made of, for example, an oxide or oxynitride containing at least one of Ti, Nb, Ta, Zn, Al, In, and Zr. Among these, oxides or oxynitrides containing at least one of Nb, Zn, and In are particularly preferable.

  Note that in the case where the first layer 122 is made of tin oxide, the first layer 122 may be cracked in the subsequent heating process. For this reason, when the heat treatment process is included in the manufacturing process of the low heat-throughflow film 100, it is not preferable that the first layer 122 is made of tin oxide.

  The thickness of the first layer 122 is, for example, in the range of 10 nm to 40 nm, and preferably in the range of 10 nm to 35 nm.

The second layer 126 may be made of a material mainly composed of, for example, SiO ₂ , SiON, or MgF ₂ .

  The thickness of the second layer 126 is, for example, in the range of 5 nm to 45 nm, and preferably in the range of 10 nm to 40 nm.

  The refractive index adjustment film 120 may be composed of a single layer having a refractive index in the range of 1.6 to 1.8 with respect to light having a wavelength of 550 nm. This layer is made of a material containing aluminum oxide, silicon oxynitride, silicon oxide, magnesium fluoride, or the like, and may have a thickness in the range of 30 nm to 90 nm.

(Transparent conductive layer 130)
The transparent conductive layer 130 is made of a material mainly composed of indium tin oxide (ITO). ITO has an infrared reflection function.

  An additive may be contained in ITO. Such additives may be, for example, silicon, aluminum, magnesium, niobium, zirconium, gallium, tungsten, zinc, tantalum, titanium, and / or potassium.

  The ratio of tin oxide in ITO is in the range of 5 wt% to 12.5 wt% of the whole, and preferably in the range of 6.5 wt% to 11 wt% of the whole. When the ratio of tin oxide is 12.5 wt% or less, the resistance tends to decrease as the amount of tin oxide increases.

  Further, the transparent conductive layer 130 may include other materials of less than 50 wt% at the maximum in addition to ITO. Such a material may be, for example, silicon, aluminum, magnesium, niobium, zirconium, gallium, tungsten, zinc, tantalum, titanium, and / or potassium.

  ITO has the effect of increasing the reflectance of infrared rays. For this reason, the emissivity of the low heat-throughflow film 100 decreases as the transparent conductive layer 130 is thicker. The thickness of the transparent conductive layer 130 is, for example, in the range of 100 nm to 200 nm, and preferably in the range of 120 nm to 170 nm. When the transparent conductive layer 130 is made of ITO, the low heat-through film 100 having a low emissivity of about 0.25 can be obtained by setting the thickness to 100 nm or more. However, when the thickness of the ITO is 200 nm or more, the amount of decrease in the emissivity per unit thickness of the ITO is reduced, and the film and the laminated film are warped, so that wrinkles and cracks are likely to occur.

  The refractive index of the transparent conductive layer 130 for light having a wavelength of 550 nm is usually in the range of 1.6 to 2.5.

(Peeling prevention layer)
A peeling prevention layer is installed as needed. By providing the peeling prevention layer, the peeling strength between the transparent conductive layer 130 and the upper layer 150 may be increased. However, the installation of the peeling prevention layer is optional.

  The peeling prevention layer may be made of, for example, a metal such as silicon, zinc, zirconium, silicon nitride, titanium nitride, titanium, aluminum, and cerium oxide, a metal nitride, and a metal oxide. The thickness of the peeling prevention layer is, for example, in the range of 1 nm to 10 nm.

(Upper layer 150)
The upper layer 150 is disposed to protect a layer existing therebelow, for example, the transparent conductive layer 130 and / or the anti-peeling layer. For example, the heat resistance of the transparent conductive layer 130 can be improved by installing the upper layer 150 on the transparent conductive layer 130. Further, by providing the upper layer 150, the scratch resistance is increased, and it is possible to suppress the occurrence of wear thinning or scratches in the transparent conductive layer 130.

  Moreover, when the suitable upper layer 150 is installed, the transmittance | permeability of the visible light region of the low heat-throughflow film 100 can be raised.

The upper layer 150 is preferably made of a material having a refractive index of 1.6 or less with respect to light having a wavelength of 550 nm, and more preferably made of a material having a refractive index of 1.55 or less. Examples of such a material include silica (SiO ₂ ), SiON, and MgF ₂ . The upper layer 150 may be a layer mainly composed of silica (SiO ₂ ), for example. The upper layer portion 150 may include other materials that are less than 50 wt% at the maximum. Such a material may be aluminum, zirconium, tin or the like. (The durability against friction is further improved by these additives.) In this case, the heat resistance of the transparent conductive layer 130 can be increased. In addition, it is possible to suppress the occurrence of wear thinning, scratches, or the like in the transparent conductive layer 130.

  The thickness of the upper layer 150 is, for example, in the range of 10 nm to 100 nm. The thickness of the upper layer 150 is preferably in the range of 10 nm to 60 nm, for example.

(Adhesive layer)
In addition, the low heat-throughflow film 100 may have an adhesive layer. The adhesive layer is usually disposed on the second surface 114 side of the film substrate 110. The low heat-throughflow film 100 can be attached to an object such as glass through the adhesive layer.

  The pressure-sensitive adhesive layer may be composed of only a pressure-sensitive adhesive, or may be one in which various additives are added to the pressure-sensitive adhesive. In the latter case, examples of the additive include an infrared reflector, an infrared absorber, and an ultraviolet absorber.

  Examples of the pressure sensitive adhesive include acrylic materials, silicone materials, urethane materials, and butadiene materials. In particular, an acrylic adhesive is preferable. The acrylic pressure-sensitive adhesive may be a polymer containing an acrylic monomer unit as a main component. In this case, the acrylic monomer includes (meth) acrylic acid, itaconic acid, (anhydrous) maleic acid, (Anhydrous) fumaric acid, crotonic acid, and alkyl esters thereof may be used. Here, (meth) acrylic acid means a general term for acrylic acid and methacrylic acid.

  As the ultraviolet absorber, for example, a triazine-based material can be used.

(Low thermal once-through film 100)
The low heat-throughflow film 100 preferably has a vertical emissivity in the range of 0.1 to 0.3. Such emissivity can significantly reduce the thermal transmissivity for light of infrared and far infrared wavelengths.

In the low heat-throughflow film 100, the a ^* value and b ^* value in the CIE 1976 L ^* a ^* b color space of reflected light generated when light is incident at an incident angle of 0 ° are −10 ≦ a ^* value ≦ 3, and − It is preferable to satisfy 15 ≦ b ^* value ≦ 10. Further, the color coordinates in the reflected light when the incident angle of light is 60 ° (a ^{*, b *)} are the color coordinates in the reflected light when the incident angle of light is 5 ° (a ^{*, b *)} and the The distance is preferably 5 or less. In this case, the angle dependency of the reflected light can be significantly suppressed.

  The low heat flow-through film 100 is used by being attached to a glass member or the like, for example. Such a glass member may be a window glass of a building, a glass member of a vehicle (for example, a windshield, a rear glass, a side glass, and a roof glass). Furthermore, the glass member may be used for a refrigeration apparatus, a refrigeration apparatus, a showcase, and the like.

(Manufacturing method of low heat-throughflow film according to one embodiment of the present invention)
Next, with reference to FIG. 2, an example of the manufacturing method of the low heat-throughflow film by one Embodiment of this invention which has the above characteristics is demonstrated. Here, as an example, a manufacturing method thereof will be described using the low heat-throughflow film 100 as shown in FIG. 1 as an example.

  In FIG. 2, an example of the flow of the manufacturing method of the low heat-throughflow film by one Embodiment of this invention is shown typically.

As shown in FIG.
Providing a film substrate having first and second surfaces (step S110);
Installing a refractive index adjusting film on the first surface of the film substrate (step S120);
Installing a transparent conductive layer on the refractive index adjusting film (step S130);
Installing an anti-peeling layer on the transparent conductive layer (step S140);
Installing an upper layer on the anti-peeling layer (step S150);
Have In addition, you may abbreviate | omit step S140, ie, installation of a peeling prevention layer.

  Hereinafter, each step will be described in detail. In the following description, the reference numerals used in FIG. 1 are used to represent each member for the sake of clarity.

(Step S110)
First, the film substrate 110 is prepared.

  As described above, the film substrate 110 may be made of a transparent resin, for example.

(Step S120)
Next, the refractive index adjustment film 120 is installed on the first surface 112 of the film substrate 110.

  As described above, the refractive index adjustment film 120 may be formed of a plurality of layers including the first layer 122 and the second layer 126. Among these, the first layer 122 closer to the film base 110 is made of a material mainly composed of an oxide or oxynitride containing at least one of Ti, Nb, Ta, Zn, Al, In, and Zr, for example. Is done. For example, the first layer 122 may be a layer mainly composed of zinc tin oxide. On the other hand, the second layer 126 may be a layer mainly composed of silica.

  The first and second layers 122 and 126 are formed, for example, by sputtering, vacuum deposition, ion plating, chemical vapor deposition, or wet deposition. The first and second layers 122 and 126 are particularly preferably formed by a sputtering method. This is because the sputtering method has a small environmental load, and the layer obtained by the sputtering method has a relatively uniform thickness.

  Examples of the sputtering method include a DC sputtering method, an AC sputtering method, a DC pulse sputtering method, a high frequency sputtering method, and a high frequency superimposed DC sputtering method. As the sputtering method, a magnetron sputtering method may be employed.

  The first layer 122 is formed with a thickness of 10 nm to 40 nm, for example, and the second layer 126 is formed with a thickness of 5 nm to 45 nm, for example.

(Step S130)
Next, the transparent conductive layer 130 mainly composed of ITO is disposed on the refractive index adjustment film 120.

  The transparent conductive layer 130 is formed, for example, by sputtering, vacuum deposition, ion plating, chemical vapor deposition, or wet deposition. As described above, examples of the sputtering method include a DC sputtering method, an AC sputtering method, a DC pulse sputtering method, a high frequency sputtering method, and a high frequency superimposed DC sputtering method. As the sputtering method, a magnetron sputtering method may be employed.

  The transparent conductive layer 130 is formed with a thickness of 100 nm to 200 nm, for example.

  Note that when the transparent conductive layer 130 is formed by a sputtering method, the film formation temperature of the film substrate 110 is not particularly limited. However, it is preferable that the film formation temperature be suppressed to such an extent that wrinkles due to heat load on the film do not occur. For example, the temperature of the film substrate 110 during the formation of the transparent conductive layer 130 by sputtering is preferably 170 ° C. or lower.

  The transparent conductive layer 130 may be formed, for example, by forming an amorphous ITO layer on the refractive index adjusting film 120 and then crystallizing it. The heat treatment temperature for crystallization is, for example, in the range of 50 ° C to 180 ° C. With this method, an ITO layer with a low vertical emissivity can be obtained.

  Note that this heat treatment (hereinafter referred to as “crystallization heat treatment”) may be performed after the next step of forming the peeling prevention layer 140 (step S140). For example, the crystallization heat treatment may be performed after forming all the layers.

(Step S140)
Next, a peel preventing layer is provided on the transparent conductive layer 130.

  The peeling prevention layer is made of, for example, a metal oxide such as cerium oxide, and may be formed by a sputtering method.

  The peeling prevention layer is, for example, in the range of 1 nm to 10 nm.

  However, this step may be omitted.

(Step S150)
Next, the upper layer 150 is disposed on the peeling prevention layer (the transparent conductive layer 130 when no peeling prevention layer is present). The upper layer 150 may be made of a material mainly composed of silica (SiO ₂ ).

  The upper layer 150 is formed by, for example, sputtering, vacuum deposition, ion plating, chemical vapor deposition, or wet deposition. As described above, examples of the sputtering method include a DC sputtering method, an AC sputtering method, a DC pulse sputtering method, a high frequency sputtering method, and a high frequency superimposed DC sputtering method. As the sputtering method, a magnetron sputtering method may be employed.

  The upper layer 150 is formed with a thickness of 10 nm to 100 nm, for example.

  Thereafter, if necessary, an adhesive layer is placed on the second surface 114 side of the film substrate 110. In addition, since the installation method of an adhesion layer is clear to those skilled in the art, it is not demonstrated here.

  Through the above steps, the low heat-through film 100 according to the embodiment of the present invention can be manufactured.

  In addition, the said manufacturing method is only an example, Comprising: It is clear to those skilled in the art that the low heat-throughflow film by one Embodiment of this invention can be manufactured also using another manufacturing method.

  Next, examples of the present invention will be described.

Example 1
A low thermal permeability film was produced by the following method.

  First, a PET film (thickness: 100 μm) having an adhesive layer on one surface (second surface) was prepared. Next, the other surface (first surface) of this PET film was dry-cleaned using an ion beam.

  In the dry cleaning treatment, a mixed gas of oxygen gas and argon gas (oxygen gas amount: about 30 vol%) is introduced into the ion beam forming apparatus, and argon ions and oxygen ions ionized by the ion beam are used as the first PET film. It was carried out by irradiating the surface of

Next, a refractive index adjusting film was formed on the first surface after the PET film was washed. The refractive index adjusting film has a two-layer structure of an indium tin oxide (ITO) layer (first layer), a silica (SiO ₂ ) layer, and a (second phase).

  The first first layer was formed by an AC magnetron sputtering method using an ITO target containing 10 wt% tin oxide. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and the pressure was 0.8 Pa. Thereby, an ITO layer having a thickness of 25 nm was formed (refractive index at a wavelength of 550 nm = 1.83).

  In addition, the film thickness of each layer in Example 1 is the value calculated | required from the relationship between the film-forming speed | rate at the time of sputtering, and sputtering time (same in the following Examples and Comparative Examples).

  The next second layer was formed by AC magnetron sputtering using a target made of polycrystalline silicon. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and was performed at a pressure of 0.3 Pa. As a result, a silica layer having a thickness of 30 nm was formed (refractive index at a wavelength of 550 nm = 1.47).

  Next, an ITO layer was formed as a transparent conductive layer on the refractive index adjustment film by AC magnetron sputtering.

  As the target, an ITO target containing 10 wt% of tin oxide was used. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and the film was formed at a pressure of 0.8 Pa. Thereby, an ITO layer having a thickness of 150 nm was formed (refractive index at a wavelength of 550 nm = 1.83).

  Next, a silica layer was formed as an upper layer on the transparent conductive layer by an AC magnetron sputtering method.

  A target made of polycrystalline silicon was used as the target. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and was performed at a pressure of 0.3 Pa. As a result, a silica layer having a thickness of 25 nm was formed (refractive index at a wavelength of 550 nm = 1.47).

  Through the above steps, a low thermal conductivity film (referred to as “film according to Example 1”) was obtained.

  Further, after the obtained film according to Example 1 was cut out to a predetermined size, this film was attached to one surface of a soda lime glass plate (thickness 3 mm) via an adhesive layer for testing. (Hereinafter referred to as “Sample 1”).

(Example 2)
A film according to Example 2 was produced in the same manner as in Example 1. However, in Example 2, the thickness of the first layer (ITO) of the refractive index adjusting film is 19 nm, the thickness of the second layer (silica layer) is 30 nm, and the film of the silica layer which is the upper layer The thickness was 60 nm. Other conditions are the same as in the first embodiment.

  In addition, a test sample (hereinafter referred to as “sample 2”) was produced using the film according to example 2 by the same method as in example 1.

Example 3
A film according to Example 3 was produced in the same manner as in Example 1. However, in Example 3, the thickness of the first layer (ITO) of the refractive index adjusting film is 24 nm, the thickness of the second layer (silica layer) is 33 nm, and the film of the silica layer which is the upper layer The thickness was 90 nm. Other conditions are the same as in the first embodiment.

  In addition, a test sample (hereinafter referred to as “sample 3”) was produced using the film according to example 3 by the same method as in example 1.

  Table 1 below collectively shows the layer configurations of the films according to Examples 1 to 3.

（比較例１）
以下の方法で、低熱貫流率フィルムを製造した。

(Comparative Example 1)
A low thermal permeability film was produced by the following method.

  First, a PET film having a first surface subjected to a dry cleaning treatment was prepared in the same manner as in Example 1.

  Next, an oxide layer of zinc and tin was formed as a first layer on the first surface of the PET film by an AC magnetron sputtering method.

  A tin target containing 30 mol% of zinc was used as the target. The film formation atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and film formation was performed at a pressure of 0.3 Pa. As a result, a 40 nm thick zinc and tin oxide layer was formed.

  Next, a silver alloy layer was formed as a second layer on the first layer by an AC magnetron sputtering method.

  As the target, a silver target containing 4 mol% of palladium was used. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and the film was formed at a pressure of 0.4 Pa. As a result, a silver alloy layer having a thickness of 12 nm was formed.

  Next, an oxide layer of zinc and tin was formed as a third layer on the second layer by an AC magnetron sputtering method.

  The deposition conditions for the third layer are the same as those for the first layer. As a result, a 40 nm thick zinc and tin oxide layer was formed.

  Next, a silica layer was formed as a fourth layer on the third layer by an AC magnetron sputtering method.

  A target made of polycrystalline silicon was used as the target. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and was performed at a pressure of 0.3 Pa. Thereby, a silica layer having a thickness of 40 nm was formed.

  Through the above steps, a low thermal conductivity film (referred to as “film according to Comparative Example 1”) was obtained.

  Furthermore, after cutting out the film according to Comparative Example 1 thus obtained to a predetermined size, this film was attached to one surface of a soda lime glass plate via an adhesive layer, thereby giving a test sample (hereinafter, (Referred to as “Sample 4”).

(Comparative Example 2)
A film according to Comparative Example 2 was produced in the same manner as in Comparative Example 1. However, in Comparative Example 2, a silver target containing 8 mol% of palladium was used as a target for forming the silver alloy layer as the second layer. Other conditions are the same as in Comparative Example 1.

  In addition, a test sample (hereinafter referred to as “sample 5”) was produced using the film according to comparative example 2 by the same method as in comparative example 1.

(Comparative Example 3)
A film according to Comparative Example 3 was produced in the same manner as in Comparative Example 1. However, in Comparative Example 3, a tin target containing 50 mol% of zinc was used as a film formation target for the first layer and the third layer. Other conditions are the same as in Comparative Example 1.

  In addition, a test sample (hereinafter referred to as “sample 6”) was produced using the film according to comparative example 3 by the same method as in comparative example 1.

  Table 2 below collectively shows the layer configurations of the films according to Comparative Examples 1 to 3.

（評価）
次に、各サンプル１〜６を用いて、以下の特性評価を実施した。

(Evaluation)
Next, the following characteristic evaluation was implemented using each sample 1-6.

(Evaluation of heat transmissibility)
The heat transmissivity was evaluated using each sample 1 to 6 having a size of 50 mm × 50 mm by the following method.

  First, the vertical emissivity of each sample 1-6 is measured using a Fourier transform infrared spectrophotometer (FT / IR-420: manufactured by JASCO Corporation). The measurement of the vertical emissivity was performed according to JIS R3106.

  Next, the heat transmissivity was determined from the obtained vertical emissivity by the method described in JIS A5759.

  At the time of evaluation, the obtained sample having a heat flow rate of 4.5 or less was regarded as a low heat flow rate sample, and a sample having a heat flow rate exceeding 4.5 was judged as a non-low heat flow rate sample.

  As a result, it was found that Samples 1 to 6 were all low heat flow samples.

(Evaluation of scratch resistance)
The scratch resistance was evaluated using each sample 1 to 6 having a size of 100 mm × 100 mm by the following method.

  First, the sample is placed horizontally on a sliding tester so that the upper layer of the film is on the upper side. The sliding tester has a pressing member having a horizontal surface at the top of the horizontal table. White felt is installed on the horizontal surface of the pressing member.

  Next, a predetermined chemical solution is dropped on the upper layer so that the chemical solution spreads with a diameter of about 20 mm. Next, the horizontal surface of the pressing member of the sliding tester is brought into contact with the upper layer of the sample, and a load of 500 g is applied from above.

  Next, in this state, the horizontal surface of the pressing member is reciprocated in the horizontal direction with respect to the sample. The moving distance in the horizontal direction is 50 mm, and the horizontal surface is moved 50 mm in the forward direction, and then moved in the opposite direction (return direction) by the same distance. This operation is repeated 2000 times at a speed of 12 reciprocations / minute.

  After the sliding operation, the sliding surface of the sample is visually observed to evaluate the presence or absence of scratches. Samples with no scratches were judged to have good scratch resistance, and samples with scratches were judged to have poor scratch resistance.

  In addition, neutral detergent, alkaline detergent, ethanol, and pure water were used as the chemical solution.

  Table 3 below collectively shows the results obtained for each of Samples 1 to 6.

表において、○は、サンプルの上部層に傷が認められなかったことを示しており、×は、サンプルの上部層に傷が認められたことを示している。なお、表３の「薬液」の欄において、「なし」とは、薬液を滴下せずに（すなわち乾燥状態で）、上記試験を行った際の結果である。ただし、この場合、押し付け部材の往復回数は、５０００回とした。

In the table, ◯ indicates that no scratch was observed in the upper layer of the sample, and x indicates that a scratch was observed in the upper layer of the sample. In the column of “Chemical Solution” in Table 3, “None” is the result when the above test was performed without dropping the chemical solution (that is, in a dry state). However, in this case, the number of reciprocations of the pressing member was 5000.

  From the evaluation results of scratch resistance, it can be seen that Samples 1 to 3 using the films according to Examples 1 to 3 can obtain good scratch resistance in any test regardless of the type of chemical solution. It was. Further, it was found that Sample 1 to Sample 3 can obtain good scratch resistance even in a “dry” state in which no chemical solution is used.

  On the other hand, in Samples 4 to 6 using the films according to Comparative Examples 1 to 3, it was found that very good scratch resistance could not be obtained depending on the type of the chemical solution.

(Angle dependence of reflected color)
Next, using sample 1, the angle dependency of the reflected color was evaluated by the following method.

  Sample 1 is irradiated with visible light (wavelength 340 nm to 840 nm) at a predetermined angle (5 ° to 60 °) from the upper layer side with a spectrophotometer (U4100: manufactured by Hitachi High-Technology Corporation) in accordance with JISK5602. The reflected color obtained was measured.

The obtained reflected color was expressed in CIE 1976 L ^* a ^* b ^* color space (D65 light source, 10 ° field of view).

  FIGS. 3 to 6 are diagrams in which the reflected colors generated when light is irradiated at each incident angle in Samples 1 to 4 are plotted on the color coordinates of the color space.

  3 to 6, it is possible to quantitatively grasp the change in the reflected color that occurs when the incident angle of light changes from 5 ° to 60 ° in each sample.

  From FIG. 3, it can be seen that in sample 1, the color coordinate of the reflected light does not change much even if the incident angle changes from 5 ° to 60 °. Similarly, it can be seen from FIGS. 4 and 5 that in Samples 2 and 3, the color coordinates of the reflected light do not change much even if the incident angle changes from 5 ° to 60 °.

  On the other hand, as shown in FIG. 6, in the case of sample 4, it was found that when the incident angle changes from 5 ° to 60 °, the color coordinate of the reflected light changes greatly.

  Thus, it was confirmed that Sample 1 to Sample 3 significantly suppressed the angle dependency of the reflected color from the sample.

Example 4
A film according to Example 4 was produced in the same manner as in Example 1 described above. However, in Example 4, a three-layer structure composed of the first layer to the third layer was used as the refractive index adjusting film.

  The first layer was alumina (refractive index at a wavelength of 550 nm = 1.71), and the thickness was 20 nm. The second layer was titania (refractive index at a wavelength of 550 nm = 2.41), and the thickness was 6 nm. The third layer was silica (refractive index at a wavelength of 550 nm = 1.47), and the thickness was 20 nm.

  The first layer was formed by an AC magnetron sputtering method using an aluminum target. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and the pressure was 0.4 Pa.

  The second layer was formed by an AC magnetron sputtering method using a titanium target. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and the pressure was 0.4 Pa.

  The third layer was formed by AC magnetron sputtering using a target made of polycrystalline silicon. The film forming atmosphere was a mixed gas atmosphere of argon gas and oxygen gas, and was performed at a pressure of 0.3 Pa.

  On the refractive index adjusting film, an ITO layer having a thickness of 150 nm was formed as a transparent conductive layer. Further, a silica layer having a thickness of 25 nm was formed as an upper layer on the transparent conductive layer. The film forming conditions for these layers are the same as those in the first embodiment.

  Thereafter, a test sample (hereinafter referred to as “sample 7”) was produced using the film according to example 4 by the same method as in example 1.

(Example 5)
A film according to Example 5 was produced in the same manner as in Example 4. However, in Example 5, titania having a thickness of 7 nm was used as the first layer of the refractive index adjustment film. Further, alumina having a thickness of 13 nm was used as the second layer of the refractive index adjusting film. Further, silica having a thickness of 26 nm was used as the third layer of the refractive index adjusting film.

  Other conditions are the same as in the fourth embodiment.

  A test sample (hereinafter referred to as “sample 8”) was produced using the film according to example 5 by the same method as in example 1.

  Table 4 below collectively shows the layer configurations of the films according to Examples 4 to 5.

（熱貫流率の評価および耐擦傷性の評価）
サンプル７およびサンプル８を用いて、前述のような熱貫流率の評価、および耐擦傷性の評価を行った。

(Evaluation of heat flow rate and scratch resistance)
Sample 7 and Sample 8 were used for the evaluation of the thermal conductivity and the scratch resistance as described above.

  As a result of the evaluation of the heat flow rate, it was found that both Sample 7 and Sample 8 were low heat flow samples. In addition, as a result of the evaluation of scratch resistance, it was found that Sample 7 and Sample 8 were able to obtain good scratch resistance in any test regardless of the type of chemical solution. Sample 7 and sample 8 were also found to have good scratch resistance even in a “dry” state where no chemical solution was used.

(Evaluation of angle dependency of reflected color)
Next, using Sample 7 and Sample 8, the angle dependency of the reflected color was evaluated by the above-described method.

  FIGS. 7 and 8 are diagrams in which the reflected colors generated when light is irradiated at the respective incident angles in the samples 7 and 8 are plotted on the color coordinates of the color space.

  7 and 8, it is possible to quantitatively grasp the change in reflected color that occurs when the incident angle of light changes from 5 ° to 60 ° in each sample.

  From FIG. 7, it can be seen that in sample 7, the color coordinates of the reflected light do not change much even if the incident angle changes from 5 ° to 60 °. Similarly, it can be seen from FIG. 8 that in sample 8, the color coordinate of the reflected light does not change much even if the incident angle changes from 5 ° to 60 °. From this, it was confirmed that in Sample 7 and Sample 8, the angle dependency of the reflected color from the sample was significantly suppressed.

  The present invention can be used for a film or the like attached to the surface of various glass members.

DESCRIPTION OF SYMBOLS 100 Low heat flow film 110 Film base material 112 1st surface 114 2nd surface 120 Refractive index adjustment film | membrane 122 1st layer 126 2nd layer 130 Transparent conductive layer 150 Upper layer

Claims (7)

A film substrate having first and second surfaces;
Disposed on the first surface of the film substrate and having at least a first layer and a second layer, the first layer being closer to the film substrate than the second layer, and having a wavelength A refractive index adjusting film having a refractive index higher than that of the second layer with respect to 550 nm light;
A transparent conductive layer mainly composed of indium tin oxide (ITO) disposed on the refractive index adjusting film;
An upper layer disposed on the transparent conductive layer and having a refractive index of 1.55 or less for light having a wavelength of 550 nm;
A low thermal flow-through film.   The low heat flow through film of claim 1, wherein the transparent conductive layer has a thickness in the range of 100 nm to 200 nm.   The low thermal flux film according to claim 1 or 2, wherein the upper layer has a thickness in the range of 10 nm to 100 nm. The top layer, the SiO ₂ as a main component, the low heat transmission film according to any one of claims 1 to 3. The first layer is made of an oxide or oxynitride containing at least one of Ti, Nb, Ta, Zn, Al, In, and Zr, and / or the second layer is made of SiO ₂ The low heat flow-through film according to any one of claims 1 to 4, comprising:   The low heat flow-through film according to any one of claims 1 to 5, wherein an adhesive layer is provided on the second surface of the film substrate.   The low thermal flow-through film according to any one of claims 1 to 6, wherein the film base is made of a transparent resin.

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