JPH07315877A - Heat shielding glass for motor vehicle - Google Patents

Abstract

PURPOSE:To prevent the reduction in the gain characteristics on transmission and reception of electric waves, thus obtain desired and sufficient benefits by providing a heat shielding film mainly made of a metal nitride containing a specific first metal and a second metal on the window glasses for cars. CONSTITUTION:An Ag-Si alloy target is set, for example, in a direct current magnetron sputterer, then a base plate of soda lime glass having an antenna 4 printed is cleaned, dried and placed in a vacuum system. The system is evacuated, an Ar gas is introduced into the system, and electric power is applied to the target to conduct presputtering. Then, the system including the vacuum tank is replaced with an N2 gas and electric power is applied to form an AgSixNy film. Thus, a heat shielding film 5 is obtained that has a sheet resistance of higher than 20kOMEGA/square and is mainly composed of metal nitride containing the first metal selected from Nb, W, Fe, Pt and the like and the second metal selected from Si, B and Al wherein the amount of the second metal is less than 80atom.% based on the total of the first metals, and the film is laminated to the glass 1 for the car windows.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window glass for an automobile which has a relatively high visible light transmittance while improving the cooling and heating effect.

[0002]

2. Description of the Related Art In recent years, in addition to radio receivers for AM broadcasting, FM broadcasting, and the like, automobiles tend to be equipped with various transmission / reception devices such as television receivers and wireless telephones.

On the other hand, recently, the window glass plate of an automobile tends to be formed with a large area, and heat rays such as direct sunlight enter through the window surface to cause an inconvenience such as an increase in the temperature inside the vehicle. ing. In order to eliminate such inconvenience as much as possible, there has been proposed a method of applying a metal thin film having a high heat ray reflection property to a glass plate to suppress the inflow of heat rays into the vehicle, and it has been partially used.

Since such a metal thin film has a high visible light reflectance, a low visible light transmittance and a glaring feeling, it is actually used after being provided with an antireflection film. For example, a metal thin film may be formed of ZnO, SnO ₂ , TiO ₂ ,
It is sandwiched between metal oxides such as Bi ₂ O ₃ and is used in a form in which interference is utilized to reduce reflection by a metal thin film and, at the same time, durability is improved.

[0005]

When a metal thin film such as Ag is used as a heat ray reflective film, it has electric conductivity and has a sheet resistance of several Ω / □ to 10 Ω / □. The electromagnetic shielding property is accordingly high. On the other hand, as described above, since the radio wave is an electromagnetic wave, when the above-mentioned metal thin film heat ray reflective film is applied, the radio wave is blocked by the heat ray reflective film having a high electromagnetic shielding property. There is a problem in that the gain characteristic during transmission and reception is deteriorated and a necessary and sufficient gain cannot be obtained.

It is an object of the present invention to provide a heat ray-shielding glass for automobiles, which solves the above-mentioned problems of the prior art found when the glass surface is also provided with a heat ray-shielding function.

[0007]

The present invention is a heat ray-shielding glass for automobiles provided with a heat ray-shielding film, wherein the heat ray-shielding film has a sheet resistance value of 20 kΩ / □ or more, and N
at least one first selected from the group consisting of b, W, Fe, Co, Ni, Ag, Cu, Au, Pd and Pt
A heat ray-shielding glass for an automobile, which is a heat ray-shielding film containing, as a main component, a metal nitride consisting of the above metal and at least one second metal selected from the group consisting of Si, B and Al. is there.

FIG. 1 is a plan view showing an example of the heat ray shielding glass 1 of the present invention in a state in which a heat ray shielding film 5 is provided on a glass plate for a rear window of an automobile.

As described above, the window glass 1 provided with the heat ray shielding film 5 has a laminated structure in which two glass plates or two or more glass plates are laminated with a laminated intermediate film such as a polyvinyl butyral film and joined. In addition to glass or glass in which a scratch-resistant plastic film is attached to the inner surface of the glass plate, a single-layer glass having a single-layer structure can be used.

In the present invention, a heat ray shielding film having a sheet resistance value of 20 kΩ / □ or more is used as the heat ray shielding film 5 so that the heat ray shielding film 5 does not shield the radio waves to be transmitted and received. It is a feature. Particularly, it is more preferable if it is 50 kΩ / □ or more.

The heat ray shielding film 5 in the present invention needs to be formed of a thin film having a high resistance value in order to eliminate the electromagnetic shielding characteristics and prevent the diffusion of electromagnetic waves. Specifically, Nb, W, Fe, Co, Ni, Ag, Cu,
At least one first metal (hereinafter referred to as metal M1) selected from the group consisting of Au, Pd, and Pt, and Si,
A heat ray-shielding film containing a metal nitride containing at least one second metal (hereinafter referred to as metal M2) selected from the group consisting of B and Al as a main component is used. Higher specific resistance than conventional Ag metal, 20k if proper film thickness is selected
A sheet resistance value of Ω / □ or more can be obtained.

When the content ratio of M2 is relatively small (for example, the total amount of M2 is less than 30% in atomic ratio with respect to the total amount of M1), the heat ray-shielding ability is particularly excellent, and the visible light transmittance does not decrease so much. 20 kΩ / □ at a thin film thickness of
The above sheet resistance values are obtained, and the heat ray blocking function is sufficiently exhibited, which is preferable.

When the content ratio of M2 is relatively large (for example, the total amount of M2 is 3 in atomic ratio with respect to the total amount of M1).
In the range of 0% or more and 80% or less), the heat ray blocking performance is slightly inferior, but the sheet resistance value of 500 kΩ / □ is easily obtained because of the high specific resistance, which is particularly optimal. That is, since the absorption of visible light is small, the film thickness is increased to maintain a high light transmittance and sufficient heat ray blocking performance is obtained, and even if the film thickness is increased, a high sheet resistance of 500 kΩ / □ or more is obtained. can get.

As the heat ray-shielding film 5 of the present invention, the heat ray-shielding function described above may be used as a single layer, or may be composed of at least two layers provided with a protective film for improving durability.

Although FIG. 1 shows an example in which the periphery of the heat ray shielding film is trimmed to more securely prevent the diffusion of radio waves to the vehicle body, it is not always necessary to trim.

[0016]

In this way, even if the heat ray shielding film 5 is arranged, since the heat ray shielding film 5 itself is formed of a non-conductive thin film having a high resistance value, the electromagnetic shielding characteristic is suppressed, Therefore, the gain performance of various transmission / reception devices mounted on an automobile is not impaired. Further, since the surface of the glass 1 is covered with the heat ray shielding film 5, it is possible to effectively prevent heat such as direct sunlight from entering the inside of the vehicle to raise the temperature inside the vehicle, and to reduce energy consumption such as cooling load reduction. While taking the measures, it can effectively contribute to improving the environment inside the vehicle.

[0017]

【Example】

[Example 1] An alloy target having an atomic ratio of Ag and Si of 3:97 (containing 10 ppm of P) was installed as a target in a DC magnetron sputtering apparatus. A 2 mm thick soda lime glass substrate with an antenna print is washed and dried, then placed in a vacuum device and 6 x 1
It was evacuated to about 0 ^-6 torr. At this time, the substrate was not heated.

Next, argon gas was introduced into the vacuum chamber, the pressure was adjusted to 1 × 10 ^-3 torr, and in this state, 1 W / cm ² of electric power was applied to the target for 5 minutes. Pre-sputtering was performed. After that, the atmosphere in the vacuum chamber was replaced with N ₂ gas, and the pressure was 4 × 10 ⁻³ torr.
2W to the above target in this state
/ Cm ² power is applied to the AgSi _x N _y film to a thickness of about 10 nm.
A film was formed.

When the spectral spectrum of the sample thus obtained was measured, the visible light transmittance was 73.4%, the solar radiation transmittance was 71.4%, and the visible light reflectance (on the glass surface side) was 9.
5%, and the transmitted color tone is X = 0.3123, Y = 0.32.
At 18, the color was almost neutral. The sheet resistance value of this sample was 800 kΩ / □.

This film has a stable sputtered state,
There was very little variation in the film properties from batch to batch. When this glass was used as a laminated glass and the radio wave transmission performance was measured, there was no problem.

The radio wave transparency was measured using a network analyzer (manufactured by Hewlett-Packard Co.) in order to know the shield effect, that is, the degree to which radio waves are less likely to be transmitted as compared with the printed antenna glass substrate.

[Embodiment 2] In the DC magnetron sputtering apparatus, the atomic ratio of Nb and Si as a target was 9:
The alloy target of No. 1 was installed. The soda-lime glass substrate having a thickness of 2 mm and having the antenna printed thereon was washed and dried, and then placed in a vacuum device and evacuated to about 6 × 10 ⁻⁶ torr. At this time, the substrate was not heated.

Next, argon gas was introduced into the vacuum chamber, the pressure was adjusted to be 2 × 10 ^-3 torr, and in this state, 2 W / cm ² of electric power was applied to the target for 5 minutes. Pre-sputtering was performed. After this, the atmosphere in the vacuum chamber was changed to a mixed gas of Ar and O ₂ (Ar: O ₂ = 5: 1).
And the pressure was adjusted to 2 × 10 ⁻³ torr. In this state, an electric power of 5 W / cm ² was applied to the target to form a NbSi _x O _y film with a thickness of about 10 nm.

The spectroscopic spectrum of the sample thus obtained was measured to find that the visible light transmittance was 30.0%, the solar radiation transmittance was 35.0%, and the visible light reflectance (glass surface side) was 17.
0%, and the transmitted color tone is X = 0.3111, Y = 0.31.
At 40, it was almost gray. The sheet resistance value of this sample was 10 MΩ / □ or more.

This film has a stable sputtered state,
There was very little variation in the film properties from batch to batch. When this glass was used as a laminated glass and the radio wave transmission performance was measured, there was no problem.

[Comparative Example 1] In a DC magnetron sputtering apparatus, the target atomic ratio of Ti and Si was 7:
3 alloy targets were installed. The soda-lime glass substrate having a thickness of 2 mm and having the antenna printed thereon was washed and dried, and then placed in a vacuum device and evacuated to about 6 × 10 ⁻⁶ torr. At this time, the substrate was not heated.

Next, argon gas was introduced into the vacuum chamber, the pressure was adjusted to 2 × 10 ^-3 torr, and in this state, 5 W / cm ² of electric power was applied to the target for 5 minutes. Pre-sputtering was performed. After that, the atmosphere in the vacuum chamber was changed to a mixed gas of Ar, N ₂ and O ₂ (Ar: N ₂ : O).
₂ = 5: 5: 1) and the pressure is 2 × 10 ⁻³ torr.
5W to the above target in this state
/ Cm ² of electric power is applied to the TiSi _x O _y N _z film to about 2
A 0 nm film was formed.

The spectroscopic spectrum of the sample thus obtained was measured, and the visible light transmittance was 73.1%, the solar radiation transmittance was 70.0%, and the visible light reflectance (glass surface side) was 8.
5%, and the transmitted color tone is X = 0.3200, Y = 0.33.
At 09, it had a yellowish gray color. The sheet resistance value of the heat ray shielding film formed in the same manner as above is 26 kΩ /
It was □.

This film had an unstable sputtering state, and the film characteristics, especially the transmission color tone, changed due to a slight change in O ₂ during sputtering, and the film characteristics varied greatly from batch to batch. When this glass was used as a laminated glass and the radio wave transmission performance was measured, there was no problem, but when the glass antenna performance was measured, a decrease in radio wave gain was measured.

[Comparative Example 2] An Nb target was set as a target in a DC magnetron sputtering apparatus.
The soda lime glass substrate with a printed antenna having a thickness of 2 mm and having an antenna print was washed and dried, then put in a vacuum apparatus and evacuated to about 6 × 10 ^-6 torr. At this time, the substrate was not heated.

Next, argon gas was introduced into the vacuum chamber, the pressure was adjusted to be 2 × 10 ^-3 torr, and in this state, 2 W / cm ² of electric power was applied to the target for 5 minutes. Pre-sputtering was performed. After this, the atmosphere in the vacuum chamber was changed to a mixed gas of Ar and O ₂ (Ar: O ₂ = 5: 1).
And the pressure was adjusted to 2 × 10 ⁻³ torr. In this state, a power of 5 W / cm ² was applied to the target to deposit a NbO _x film of about 30 nm.

The spectroscopic spectrum of the sample thus obtained was measured to find that the visible light transmittance was 35.0%, the solar radiation transmittance was 45.0%, and the visible light reflectance (glass surface side) was 1.
7.0%, and the transmitted color tone is X = 0.32020, Y = 0.
At 3220, it was almost gray. The sheet resistance value of the heat ray shielding film formed in the same manner as above was 10 MΩ / □ or more.

When the radio wave transmission performance of this film was measured, there was no particular problem. However, the sputtering state was unstable, and the film characteristics, particularly the transmission color tone, changed due to a slight change in O ₂ during the sputtering, resulting in large variations in the film characteristics from batch to batch.

[0034]

As described above, according to the present invention, the heat ray blocking film is formed of a thin film having a high resistance value.
The electromagnetic shielding property can be eliminated, and therefore the gain characteristic of the antenna conductor can be prevented from deteriorating due to the influence of the heat ray shielding film, and the excellent gain characteristic can be exhibited as a radio wave transmission film while preventing the heat ray from entering the vehicle. . Moreover, the sputtered state is stable, and there is an effect that there is very little variation in film characteristics between batches.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of the present invention.

[Explanation of symbols]

 1: Window glass 4: Antenna conductor 5: Heat ray shielding film

Claims (2)

[Claims] 1. A heat ray-shielding glass for automobiles provided with a heat ray-shielding film, wherein the heat ray-shielding film has a sheet resistance value of 20 kΩ / □ or more, and Nb, W, Fe, Co, Ni,
At least one first metal selected from the group consisting of Ag, Cu, Au, Pd and Pt, and Si, B and A
A heat ray-shielding glass for an automobile, which is a heat ray-shielding film containing a metal nitride containing at least one second metal selected from the group consisting of 1 as a main component. 2. The heat ray-shielding glass for automobiles according to claim 1, wherein in the heat ray-shielding film, the total amount of the second metal is 80% or less in atomic ratio with respect to the total amount of the first metal.