Patent ID: 12240204

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention is explained.

The embodiment of the present invention is a laminate including:a transparent substrate having a first surface; anda laminated film provided on the first surface of the transparent substrate,wherein the laminated film includes, in a descending order of closeness to the first surface:a first dielectric layer including silicon nitride or zinc oxide or including silicon nitride and zinc oxide;a first layer including titanium oxide and provided on or above the first dielectric layer;a first barrier layer including nickel and chromium and provided on or above the first layer; anda silver-containing metal layer provided directly on the first barrier layer.

In the laminate according to the embodiment of the present invention, the first barrier layer is configured to improve the crystal orientation and stabilize the crystal structure of the silver-containing metal layer provided on or above the first barrier layer.

In the laminate according to the embodiment of the present invention, the first layer is provided under the first barrier layer. The first layer includes titanium oxide. It is considered that a fine tetragonal material derived from titanium oxide is formed on the surface of the first layer. It is considered that a fine tetragonal material derived from titanium oxide is formed on the surface of the first layer. It is known that, in the tetragonal material, the crystals are preferentially oriented in the (110) plane (tetragonal lattice) that is the most stable plane with a least interatomic distance. Nickel and chromium, which are the first barrier layer, include a hexagonal close-packed structure and a body-centered cubic lattice, respectively. It is known that, in a case where nickel has a thickness of about several nanometers, the crystals in nickel are preferentially oriented in the plane as indicated in the following Chem. 1 when nickel is on a material in which the crystals are oriented in a tetragonal lattice form.

[Chem. 1]

1100 Plane (Tetragonal Lattice)

Also, it is known that, in the body-centered cubic lattice, the crystals are preferentially oriented in the (110) plane (tetragonal lattice) that is the most stable plane with a least interatomic distance. The planes of these materials substantially match each other. Therefore, with the first layer being provided under the first barrier layer, the crystallizability of the first barrier layer can be enhanced even if there is a difference in the crystalline system. Further, because of this, the crystallizability of the silver-containing metal layer provided directly on the first barrier layer can be enhanced. When the crystallizability of the silver-containing metal layer improves, a crystal structure having an orientation that is dominant in a particular direction can be achieved in the silver-containing metal layer. Therefore, the improvement in the crystallizability of the silver-containing metal layer can contribute to the reduction of the sheet resistance value of the entire laminate.

In this case, the sheet resistance value is a parameter correlated with the heat-insulating property of the laminate, and it follows reason that the heat-insulating property of the laminate increases in accordance with a decrease in the sheet resistance value of the laminate. Therefore, in the embodiment of the present invention, the heat-insulating property of the laminate can also be increased in accordance with the effect for reducing the sheet resistance value of the laminate.

Further, the silver-containing metal layer and the first barrier layer are in contact with each other, and zinc oxide is not included between the silver-containing metal layer and the first barrier layer, so that an alloy layer is famed at the interface between the silver-containing metal layer and the first barrier layer. As a result, the inter-layer adhesion between the first barrier layer and the silver-containing metal layer can be improved.

Therefore, in the embodiment of the present invention, a problem of delamination that could occur at the interface between layers constituting a laminated film, such as conventional heat-insulated glass, can be significantly alleviated.

As a result of the above-described effects, in the embodiment of the present invention, a laminate that has a high heat-insulating property and of which the inter-layer adhesion has been improved can be obtained.

In the present application, in order to express a balance between the heat-insulating property and the transparency of the laminate, an index Tv/Rs is introduced. In this case, Tv denotes a visible light transmittance (%) of the laminate, and Rs denotes a sheet resistance value (Ω/sq) of the laminate.

In general, a parameter referred to as a selectivity Se is often used as an index of a balance between the heat-insulating property and the transparency of the laminate. The ratio Tv/Rs can be used as an index that is correlated with this selectivity Se. Specifically, it follows reason that the laminate has a higher transparency and a higher heat-insulating property in accordance with an increase in the transmittance and a decrease in the sheet resistance value, i.e., in accordance with an increase in the ratio Tv/Rs, in the laminate.

In the present application, the term “transparent” means that the visible light transmittance is 50% or greater.

(Laminate According to the Embodiment of the Present Invention)

Hereinafter, a laminate according to the embodiment of the present invention is explained in more detail with reference toFIG.1.

FIG.1schematically illustrates a cross section of a laminate (hereinafter referred to as a “first laminate”) according to the embodiment of the present invention.

As illustrated inFIG.1, the first laminate100includes a transparent substrate110and a laminated film120.

The transparent substrate110includes a first surface112and a second surface114, and the laminated film120is provided on the first surface112of the transparent substrate110.

The laminated film120includes a first dielectric layer130, a first layer140, a first barrier layer150, a silver-containing metal layer (which may be hereinafter also simply referred to as a “metal layer”)160, a second barrier layer170, and a second dielectric layer180.

The first dielectric layer130is constituted by dielectric including silicon nitride, and is configured to reduce the visible light reflectance.

The first layer140is constituted by a material including titanium oxide. A fine tetragonal material derived from titanium oxide is considered to be formed on the surface of the first layer. It is known that, in the tetragonal material, the crystals are preferentially oriented in the (110) plane (tetragonal lattice) that is the most stable plane with a least interatomic distance. Further, the first barrier layer has a hexagonal close-packed structure and a body-centered cubic lattice. It is known that, in a case where the hexagonal close-packed structure has a thickness of several nanometers, the crystals in the hexagonal close-packed structure are preferentially oriented in the plane as indicated in the following Chem. 2 when the hexagonal close-packed structure is on a material in which the crystals are oriented in a tetragonal lattice form.

[Chem. 2]

1100 Plane (Tetragonal Lattice)

It is known that, in the body-centered cubic lattice, the crystals are preferentially oriented in the (110) plane (tetragonal lattice) that is the most stable plane with a least interatomic distance. The (110) planes of them both substantially match each other. Therefore, with the first layer being provided under the first barrier layer, the crystallizability of the first barrier layer can be enhanced even if there is a difference in the crystalline system.

In the example as illustrated inFIG.1, the first layer140is provided directly under the first barrier layer150.

The first barrier layer150is configured to improve and stabilize the crystal orientation of the metal layer160. The first barrier layer150is constituted by a material including nickel and chromium. The first barrier layer150is transparent.

As illustrated inFIG.1, the first barrier layer150is provided directly under the metal layer160.

The metal layer160includes silver, and is configured to reflect heat rays incident upon the first laminate100. The metal layer160is transparent.

As illustrated inFIG.1, the metal layer160is provided directly on the first barrier layer150.

The second barrier layer170and the second dielectric layer180are configured to protect the metal layer160from the outside. However, the second barrier layer170and the second dielectric layer180do not have to be provided.

In the first laminate100, the first layer140is provided directly under the first barrier layer150, and the metal layer160is provided directly on the first barrier layer150. In the first laminate100having such a configuration, the first layer140can improve the crystallizability of the first barrier layer150. Furthermore, this can also improve the crystallizability of the metal layer160.

Further, the silver-containing metal layer and the first barrier layer are in contact with each other, and zinc oxide is not included between the silver-containing metal layer and the first barrier layer, so that an alloy layer is famed at the interface between the silver-containing metal layer and the first barrier layer. As a result, the inter-layer adhesion between the first barrier layer150and the metal layer160can be improved.

Further, with the improvement of the crystallizability of the metal layer160, the sheet resistance value of the metal layer160is reduced, and accordingly, the sheet resistance value of the laminated film120and further the sheet resistance value of the first laminate100can be reduced. Therefore, in the first laminate100, a high ratio Tv/Rs can be obtained.

As a result of the above-described effects, with the first laminate100, a high heat-insulating property can be obtained, and furthermore, the inter-layer adhesion can be increased significantly.

(Configuration of Each Member Included in the Laminate According to the Embodiment of the Present Invention)

Next, the configuration of each member included in the laminate according to the embodiment of the present invention is explained in detail. In this case, using the first laminate100as an example, the components thereof are explained. Therefore, members are denoted with the reference numerals indicated inFIG.1.

(Transparent Substrate110)

The transparent substrate110is constituted by a transparent material such as, for example, resin or glass.

(First Dielectric Layer130)

The first dielectric layer130is constituted by dielectric including silicon nitride. The first dielectric layer130may further include Al. For example, the first dielectric layer130may be constituted by SiAlN.

The first dielectric layer130has a thickness in a range of 10 nm to 60 nm. The thickness is preferably in a range of 20 nm to 50 nm.

(First Layer140)

As described above, the first layer140includes titanium oxide. Even if the first layer140includes a hexagonal material, similar effects can be obtained.

The first layer140is preferably constituted by titanium oxide. Particularly preferably, titanium oxide is titanium dioxide (TiO2).

The thickness of the first layer140is, for example, in a range of 1 nm to 20 nm. The thickness is preferably in a range of 3 nm to 15 nm. When the thickness is in the above range, a certain amount of fine tetragonal material derived from titanium oxide is considered to be formed on the surface of the first layer140.

Further, a ratio of the thickness of the first layer140to the thickness of the first barrier layer150is preferably in a range of 0.1 to 2.5, and particularly preferably in a range of 0.25 to 2.0. When the ratio of the thickness is equal to or more than 0.1, the crystallizability of the first barrier layer150can be enhanced sufficiently. When the ratio of the thickness is equal to or less than 2.5, a high degree of adhesion can be secured. Specifically, when the ratio of the thickness is in the above-described range, a high degree of adhesion and a high ratio Tv/Rs can be obtained.

(First Barrier Layer150)

As described above, the first barrier layer150includes nickel and chromium.

The ratio of nickel to chromium included in the first barrier layer150is not particularly limited, but normally, the ratio of nickel to chromium is in a range of 50:50 to 90:10 in mass ratio.

The first barrier layer150preferably has a thickness in a range of 1 nm to 8 nm, and more preferably in a range of 1 nm to 6 nm. When the thickness of the first barrier layer150is defined as 8 nm or less, a high visible light transmittance and a high ratio Tv/Rs can be obtained. When the thickness of the first barrier layer150is equal to or more than 1 nm, a high degree of adhesion can be obtained.

(Metal Layer160)

The metal layer160is constituted by a layer including silver. The metal layer may be constituted by, for example, a silver alloy. Examples of such silver alloys include Ag—Au alloy, Ag—Pd alloy, Ag—Ni alloy, and the like. The amount of silver included in the silver alloy is preferably equal to or more than 90 mass %.

The metal layer160has a thickness in a range of 7 nm to 25 nm. When the thickness of the metal layer160is equal to or less than 25 nm, the transparency of the metal layer160increases.

(Second Barrier Layer170)

The second barrier layer170may be constituted by a material similar to the first barrier layer150. The second barrier layer170may be constituted by multiple films.

The thickness of the second barrier layer170is not limited thereto, and is, for example, in a range of 0.1 nm to 10 nm.

As described above, the second barrier layer170does not have to be provided.

(Second Dielectric Layer180)

The second dielectric layer180is constituted by any given dielectric material. The second dielectric layer180may be constituted by, for example, the same material as the first dielectric layer130.

Alternatively, in order to attain a barrier and abrasion resistance, the second dielectric layer180may be constituted by a compound represented by a general expression SixAlyNzOw, in which 0≤y/(x+y)≤0.5, 0≤w<z, 0.8<z/(x+y)<1.5, and 0≤w/(x+y)≤0.2 are satisfied.

The thickness of the second dielectric layer180is not limited thereto, and is, for example, in a range of 20 nm to 60 nm.

As described above, the second dielectric layer180does not have to be provided.

(Laminate According to Another Embodiment of the Present Invention)

Next, a laminate according to another embodiment of the present invention is explained with reference toFIG.2.

FIG.2schematically illustrates a cross section of the laminate according to the embodiment of the present invention (hereinafter referred to as a “second laminate”).

As illustrated inFIG.2, the second laminate200includes a transparent substrate210and a laminated film220.

The transparent substrate210includes a first surface212and a second surface214, and the laminated film220is provided on the first surface212of the transparent substrate210.

The transparent substrate210may have substantially the same configuration as the transparent substrate110of the first laminate100described above.

The laminated film220includes a first dielectric layer230, a first layer240, a second layer245, a first barrier layer250, a silver-containing metal layer (which may be hereinafter simply referred to as a “metal layer”)260, a second barrier layer270, and a second dielectric layer280.

In this case, with regard to the feature of each layer constituting the laminated film220other than the second layer245, the above description about the laminated film120in the first laminate100can be referred to. Therefore, hereinafter, the configuration and the feature of the second layer245are explained.

The second layer245is provided directly on the first layer240, and is provided directly under the first barrier layer250.

The second layer245includes at least one selected from the group consisting of metallic titanium, metallic chromium, titanium oxide (TiOx, in which x is 0.01 or more and is less than 2.0), metallic niobium, chromium oxide, and aluminum nitride. In particular, the second layer245is preferably constituted by metallic titanium or titanium oxide.

The second layer245is configured to further enhance the adhesion between the first layer240and the first barrier layer250. Specifically, the second layer245is interposed between the first layer240and the first barrier layer250, which makes it less likely to cause delamination between the first layer240and the first barrier layer250.

The second layer245is formed to be relatively thin, and has a thickness in a range of, for example, 0.1 nm to 10 nm. This is to inhibit the second layer245from obstructing the effect exerted by the first layer240on the first barrier layer250with respect to crystallizability.

In other words, the second layer245is formed to be thin, so that the crystallizability of the first barrier layer250having the crystal structure in which the crystals are preferentially oriented in the tetragonal lattice form can be enhanced by the fine tetragonal material included in the first layer240.

The ratio of the thickness of the second layer245to the thickness of the first barrier layer250is preferably in a range of 0.02 to 10 and particularly preferably in a range of 0.08 to 8.0. When the ratio of the thickness is in the above range, a high degree of adhesion and a high ratio Tv/Rs can be obtained.

In this manner, in the second laminate200, the adhesion between the respective layers included in the laminated film220can be significantly enhanced, in a manner similar to the first laminate100.

The second layer245is configured so as not to obstruct the consistency in the crystal structures of the first layer240and the first barrier layer250. Therefore, with the first layer240, the crystallizability of the first barrier layer250can be enhanced, and accordingly, the crystallizability of the metal layer260can also be enhanced.

As a result, the sheet resistance value of the metal layer260is reduced, and accordingly, the sheet resistance value of the laminated film220and further the sheet resistance value of the second laminate200can be reduced. Therefore, in the second laminate200, a high ratio Tv/Rs can be obtained.

As a result of the above-described effects, with the second laminate200, a high heat-insulating property can be obtained, and furthermore, the inter-layer adhesion can be increased significantly.

(Example of Application of Laminate According to the Embodiment of the Present Invention)

The laminate according to the embodiment of the present invention can be applied to members that require both of a high heat-insulating property and a high transparency such as, for example, window glass of buildings and doors of cooking ovens.

FIG.3schematically illustrates a cross section of window glass of a building (hereinafter simply referred to as “window glass300”) to which the laminate according to the embodiment of the present invention is applied.

As illustrated inFIG.3, the window glass300has an insulated glazing structure, and is made by arranging a first glass member355and a second glass member365spaced apart from each other. An internal space375is formed between them. The internal space375may be vacuum or may be filled with inert gas.

For example, the window glass300is provided on a sash and the like of a building, with a surface of the window glass300on the side of the first glass member355being on an indoor side301, and a surface of the window glass300on the side of the second glass member365being on an outdoor side303.

The first glass member355includes a first glass substrate357. On one of the surfaces of the first glass substrate357, a laminated film359is provided. The laminated film359is provided to face the internal space375.

In contrast, the second glass member365includes a second glass substrate367. In the second glass member365, the second glass substrate367alone may be used, or one of the surfaces of the second glass substrate367may be provided with a laminated film.

In this case, the first glass member355is constituted by the laminate according to the embodiment of the present invention. For example, the first glass member355may be constituted by the first laminate100or the second laminate200described above. In this case, the first glass substrate357is the transparent substrate110or the transparent substrate210described above.

In the above-described window glass300, the adhesion between the layers can be significantly improved by the laminated film359included in the first glass member355. Further, the first glass member355has a high ratio Tv/Rs. Therefore, in the window glass300, a high heat-insulating property can be achieved, and furthermore, the inter-layer delamination in the laminated film359can be alleviated.

In particular, in a case where not only the first glass member355but also the second glass member365are constituted by the laminate according to the embodiment of the present invention, the window glass300with a higher heat-insulating property can be provided.

EXAMPLES

Hereinafter, Examples of the present invention are explained. In the following description, Example 1 to Example 4 are Examples, and Example 11 to Example 13 are Comparative examples.

Example 1

According to the following method, a laminate was produced by forming a laminated film on one of the surfaces of a glass substrate.

As the glass substrate, soda lime glass with dimensions of 100 mm long, 50 mm wide, and 3.0 mm thick was used.

The laminated film was constituted by 6 layers that are, from the side closer to the glass substrate, a first dielectric layer, a first layer, a first barrier layer, a silver-containing metal layer, a second barrier layer, and a second dielectric layer.

The first dielectric layer was silicon nitride containing aluminum (target film thickness: 40 nm). The first layer was TiO2(target film thickness: 3 nm). The first barrier layer was NiCr (target film thickness: 2 nm). The silver-containing metal layer was metal silver (target film thickness: 16 nm). The second barrier layer was NiCr (target film thickness: 1 nm). The second dielectric layer was silicon nitride containing aluminum (target film thickness: 51 nm).

All of these layers were deposited by a sputtering method.

Specifically, for deposition of the first dielectric layer, a planar target made of Si-10 wt % Al was used, and a mixed gas of argon and nitrogen was used as the discharge gas. A ratio of argon to nitrogen in the mixed gas was argon:nitrogen=40:60 (sccm). The pressure during deposition was 0.42 Pa, and the incident power density was 36 kW/m2.

For deposition of the first layer, a planar target made of metal Ti was used, and oxygen gas was used as the discharge gas. The pressure during deposition was 0.42 Pa, and the incident power density was 36 kW/m2.

For deposition of the first barrier layer, a planar target made of Ni-20 wt % Cr was used, and argon gas was used as the discharge gas. The pressure during deposition was 0.48 Pa.

For deposition of the silver-containing metal layer, a planar target made of silver was used, and argon gas was used as the discharge gas. The pressure during deposition was 0.46 Pa.

For deposition of the second barrier layer, a planar target made of Ni-20 wt % Cr was used, and argon gas was used as the discharge gas. The pressure during deposition was 0.48 Pa.

For deposition of the second dielectric layer, a planar target made of Si-10 wt % Al was used. A mixed gas of argon and nitrogen was used as the discharge gas. A ratio of argon to nitrogen in the mixed gas was argon:nitrogen=40:60 (sccm). The pressure during deposition was 0.42 Pa.

The depositions of these layers were performed in the same sputtering chamber.

After the laminated film was deposited on the glass substrate, the glass substrate was baked at 730° C. for 3 minutes in the air atmosphere.

As a result, the laminate (hereinafter referred to as a “Sample 1”) was produced.

Example 2

According to substantially the same method as Example 1, a laminate was produced.

However, in this Example 2, the target film thickness of the first barrier layer was 1.4 nm. Further, Ti was deposited as the second layer between the first layer and the first barrier layer.

For deposition of the second layer, a planar target made of metal Ti was used, and argon gas was used as the discharge gas. The pressure during deposition was 0.48 Pa. The target thickness of the second layer was 1 nm.

Other production conditions were substantially the same as Example 1.

As a result, the laminate (hereinafter referred to as a “Sample 2”) was produced.

Example 3

According to substantially the same method as Example 1, a laminate was produced. However, in this Example 3, the target film thickness of the first layer was set to 1 nm.

As a result, the laminate (hereinafter referred to as a “Sample 3”) was produced.

Example 4

According to substantially the same method as Example 1, a laminate was produced.

However, in this Example 4, the target film thickness of the first barrier layer was 1.4 nm. Further, TiOx was deposited as the second layer between the first layer and the first barrier layer.

For deposition of the second layer, a planar target made of metal Ti was used, and a mixed gas of argon and oxygen was used as the discharge gas. A ratio of argon to oxygen in the mixed gas was argon:oxygen=70:10 (sccm). The pressure during deposition was 0.47 Pa. The target thickness of the second layer was 3.0 nm.

Other production conditions were substantially the same as Example 1.

As a result, the laminate (hereinafter referred to as a “Sample 4”) was produced.

Example 11

According to substantially the same method as Example 1, a laminate was produced.

However, in this Example 11, without depositing the first layer, the first barrier layer was deposited directly on the first dielectric layer.

Further, the first barrier layer was ZnO:Al (target film thickness: 5 nm).

For deposition of the first barrier layer, a target made of ZnO+3 wt % AlO2was used, and a mixed gas of argon and oxygen was used as the discharge gas. A ratio of argon to oxygen in the mixed gas was argon:oxygen=50:50 (sccm). The pressure during deposition was 0.46 Pa.

Other production conditions were substantially the same as Example 1.

As a result, the laminate (hereinafter referred to as a “Sample 11”) was produced.

Example 12

According to substantially the same method as Example 1, a laminate was produced.

However, in this Example 12, without depositing the first layer, the first barrier layer was deposited directly on the first dielectric layer. Further, the target film thickness of the first barrier layer was 1.4 nm.

Other production conditions were substantially the same as Example 1.

As a result, the laminate (hereinafter referred to as a “Sample 12”) was produced.

Example 13

According to substantially the same method as Example 1, a laminate was produced.

However, in this Example 13, the target film thickness of the first layer was 3 nm. Further, NiCr was deposited as the second layer between the first layer and the first barrier layer. Further, the first barrier layer was ZnO:Al (target film thickness: 5 nm).

For deposition of the second layer, a planar target made of NiCr was used, and argon gas was used as the discharge gas. The pressure during deposition was 0.48 Pa. The target thickness of the second layer was 2 nm.

For deposition of the first barrier layer, a target made of ZnO+3 wt % AlO2was used, and a mixed gas of argon and oxygen was used as the discharge gas. A ratio of argon to oxygen in the mixed gas was argon:oxygen=50:50 (sccm). The pressure during deposition was 0.46 Pa.

Other production conditions were substantially the same as Example 1.

As a result, the laminate (hereinafter referred to as a “Sample 13”) was produced.

The following Table 1 summarizes the configurations of the laminated films of Samples 1 to 3 and Samples 11 to 13. In the Samples, the layers higher than the silver-containing metal layer have the same technical specifications, which are omitted in Table 1.

TABLE 1Configuration of Laminated FilmRatio of FilmRatio of FilmSilver-Thicknesses:Thicknesses:FirstFirstContainingFirst Layer/Second Layer/DielectricFirstSecondBarrierMetalFirst BarrierFirst BarrierSampleLayerLayerLayerLayerLayerLayerLayer1SiAlNTiO2—NiCrAg1.5—2SiAlNTiO2TiNiCrAg2.10.713SiAlNTiO2—NiCrAg0.5—4SiAlNTiO2TiO2NiCrAg2.12.1411SiAlN——ZnO: AlAg——12SiAlN——NiCrAg——13SiAlNTiO2NiCrZnO: AlAg0.60.4
(Evaluation)

The following evaluations were conducted by using each Sample.

(Evaluation of Ratio Tv/Rs)

A visible light transmittance Tv (%) and a sheet resistance value Rs (Ω/Sq) were measured by using each Sample.

For the measurement of the visible light transmittance, a luminous transmittance meter (TLV-304-LC, manufactured by Asahi Spectra Co., Ltd.) was used. The transmittance of light from the Illuminant A incident from a surface facing the transparent substrate, measured using a luminous correction filter, was adopted as a visible light transmittance Tv (%) of each Sample.

For measurement of the sheet resistance value Rs, a sheet resistance measurement device (Conductance Monitor model717B, manufactured by Delcom Instruments, Inc.) was used. The measurement surface was a surface of a laminated film.

A ratio Tv/Rs was calculated from the visible light transmittance Tv (%) and the sheet resistance value Rs (Ω)/Sq) obtained.

(Adhesion Evaluation Examination)

An adhesion evaluation examination of a laminated film was conducted by using each Sample.

For the adhesion evaluation examination, a surface characteristics tester (IMC-1550, manufactured by Imoto Machinery Co., LTD.) was used. First, a cotton lawn (SDCE Cotton Lawn, manufactured by SDC Enterprises Limited) was attached to the end of the indentor (a circular shape with a diameter of 2 cm) supplied with this device.

Next, after the surface of the laminate film of the Sample is wetted with pure water, the end of the indenter attached with the cotton lawn was pressed against the laminated film. The contact area of the indenter was 3.1 cm2.

Next, the Sample was fixed, and while a load of 1000 g was applied to the indentor, the indentor was reciprocally moved 500 times in the horizontal direction. The movement distance in the back and forth paths in a single reciprocal movement was 40 mm.

Thereafter, the sheet resistance value of the Sample was measured by using the above-described sheet resistance measurement device.

The adhesions of the layers included in the laminated film were evaluated from a change in the sheet resistance value of the Sample before and after the examination.

In this evaluation examination, the delamination resistance in the shear direction at the interface of the respective layers included in the laminated film can be evaluated. Specifically, it follows reason that a smaller change in the sheet resistance value before and after the examination indicates a higher inter-layer adhesion.

The following Table 2 summarizes evaluation examination results obtained from the respective Samples.

TABLE 2AdhesionEvaluation ExaminationPre-Post-ExaminationExaminationAmountVisible LightSheetSheetofTransmittanceResistanceResistanceChangeSampleTv [%]Tv/Rs[Ω/sq][Ω/sq][Ω/sq]165.424.22.702.700.00264.122.42.862.860.00359.522.12.692.690.00463.822.32.862.860.001168.024.02.8320.6017.771260.118.03.343.340.001368.324.82.7515.2012.45

As shown in Table 2, in the Sample 11 and the Sample 13, before and after the adhesion evaluation examination, the values of the sheet resistances have greatly increased. Accordingly, it is considered that, in the Sample 11 and the Sample 13, a shear-like delamination occurred at the interface between a layer and a layer in the laminated film.

Further, it is understood that, in the Sample 12, a ratio Tv/Rs was low, and a fairly high heat-insulating property was not obtained.

In this manner, in the Sample 11 to the Sample 13, characteristics having both of a high heat-insulating property and a high degree of adhesion were not obtained.

In the Sample 1 to Sample 4, the ratios Tv/Rs were sufficiently high. Further, in the Sample 1 to the Sample 4, before and after the adhesion evaluation examination, a change in the sheet resistance value was not observed.

As described above, it is confirmed that the Sample 1 to the Sample 4 had high heat-insulating properties and attained high degrees of adhesions.