JP7375769B2 - window parts - Google Patents

Description

The present invention relates to a window member.

In recent years, as communication speeds have increased and communication capacity has increased, the frequency band of radio waves used for communication has expanded to higher frequencies. For example, in recent fourth generation mobile communication systems (hereinafter referred to as "4G") and fifth generation mobile communication systems (hereinafter referred to as "5G"), radio waves in the frequency band of several hundred MHz to several tens of GHz are used. There is.
Radio waves in such a high frequency band are also used in communication in the automobile field, and for example, radio waves in the 5.9 GHz band are used in ETC in Europe.

When communicating using radio waves in a high frequency band of several tens of GHz, for example, using a millimeter wave radar installed in a car, for example, the frequency range from the conventional order of several hundred MHz to less than 6 GHz called "sub6" in 5G. Compared to radio wave communication, the loss of radio waves due to window glass, etc. is significant.
Therefore, in order to solve the above problem, Patent Document 1 discloses a window member in which a radio wave transmitting member is partially fitted to form a region with high radio wave transmittance.

International Publication No. 2017/188415

However, Patent Document 1 does not disclose the conditions necessary to obtain desired radio wave transparency, the specific material of the radio wave transmitting member, the structure of the window glass, etc.

In view of the above, an object of the present invention is to provide a window member with excellent radio wave transparency.

A window member of the present invention that solves the above problems includes a first glass plate having a thickness of 1.1 mm or more and a radio wave transmitting member facing the main surface of the first glass plate, and transmits radio waves in a plan view. Transmittance T (F) of radio waves of frequency F (GHz) incident on the area provided with the member at an incident angle of 67.5° with respect to the main surface of the first glass plate is in the range of 60 GHz≦F≦100 GHz. The following formula (1) is satisfied.
T(F)>-0.0061×F+0.9384...(1)

Further, in one aspect of the present invention, the window member has a frequency F (GHz) that is incident on the region including the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in plan view. The radio wave transmittance T(F) may satisfy the following formula (2) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+0.9784...(2)

Further, in one aspect of the present invention, the window member has a frequency F (GHz) that is incident on the region including the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in plan view. The radio wave transmittance T(F) may satisfy the following formula (3) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0384...(3)

Further, in one aspect of the present invention, the window member has a frequency F (GHz) that is incident on the region including the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in plan view. The radio wave transmittance T(F) may satisfy the following formula (4) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0554...(4)

Further, in one aspect of the present invention, the window member includes a first region including a radio wave transmitting member in a plan view, and a second region not including a radio wave transmitting member in a plan view, and in the second region, A second glass plate may be provided that faces the main surface of the first glass plate.

Further, in one aspect of the present invention, the window member may include a radio wave transmitting member in the entire area facing the main surface of the first glass plate, and the radio wave transmitting member may be made of glass.

Further, in one aspect of the present invention, the radio wave transmitting member may include at least one urethane resin layer.

Moreover, in one aspect of the present invention, the radio wave transmitting member may further include a polycarbonate resin layer laminated on the surface of the above-mentioned urethane resin layer that is opposite to the first glass plate side.

Moreover, in one aspect of the present invention, the above-described urethane resin layer may be adjacent to the first glass.

Moreover, in one aspect of the present invention, the window member may include a transparent resin layer between the first glass plate and the radio wave transmitting member.

Further, in one embodiment of the present invention, the transparent resin layer may contain at least one member selected from the group consisting of polyvinyl butyral, ethylene vinyl acetate, and cycloolefin polymer.

Further, in one embodiment of the present invention, the transparent resin layer may be an adhesive layer.

Further, in one embodiment of the present invention, the radio wave transmitting member may be made of alkali-free glass or resin.

Further, in one embodiment of the present invention, the radio wave transmitting member may be made of a cycloolefin polymer.

In one embodiment of the present invention, at least one of the first glass plate and the radio wave transmitting member has a content expressed as a molar percentage based on oxides of each component, such as RO, MgO, CaO, SrO, and BaO. When the total amount, R ₂ O, is the total amount of alkali metal oxide,
50≦ _SiO2 ≦85
0≦ _{Al2O3 ≦} 20
4≦ _R2O ≦22
0≦RO≦20
0≦ _Na2O / _R2O ≦0.8
0≦ _K2O / _R2O ≦0.7
It may be made of glass having a composition A that satisfies the following. Further, both the first glass plate and the radio wave transmitting member may be made of glass having composition A.

Further, in one aspect of the present invention, at least one of the first glass plate and the radio wave transmitting member contains SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ in a content expressed as a mole percentage based on oxides of each component. The total amount of glass may be 72% or more.

In one embodiment of the present invention, at least one of the first glass plate and the radio wave transmitting member has a content expressed as a molar percentage based on oxides of each component, such as RO, MgO, CaO, SrO, and BaO. When the total amount, R ₂ O, is the total amount of alkali metal oxide,
72≦SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ≦98
55≦ _SiO2 ≦87
0≦ _{Al2O3 ≦} 20
5≦ _{B2O3 ≦} 25
0≦R ₂ O≦5
0≦RO≦20
0≦ _{Al2O3 / B2O3 ≦} 0.35
It may be made of glass having a composition C that satisfies the following. Further, both the first glass plate and the radio wave transmitting member may be made of glass having composition C.

Further, in one aspect of the present invention, the total thickness of the window member may be 3.5 mm or more and 10 mm or less, and the thickness of the radio wave transmitting member may be 0.4 mm or more and 2.5 mm or less.

The window member of the present invention has excellent radio wave transparency.

FIG. 1 is a front view of the window member of the first embodiment. FIG. 2 is a cross-sectional view of the window member taken along line XX in FIG. FIG. 3 is a conceptual diagram showing a state in which the window member of the first embodiment is used as a window glass for an automobile. FIG. 4 is an enlarged view of the S portion in FIG. 3. FIG. 5 is a cross-sectional view taken along the YY line in FIG. 4. FIG. 6A is a cross-sectional view of an example of the window member of the second embodiment. FIG. 6B is a cross-sectional view of an example of the window member of the second embodiment. FIG. 7 is a sectional view of a window member according to the third embodiment. FIG. 8 is a sectional view of a window member according to the fourth embodiment. FIG. 9 is a diagram showing the measurement results of the transmittance T(F) of a radio wave having a frequency F (GHz) incident at an incident angle of 67.5° for a window member of a comparative example. FIG. 10 is a diagram showing the measurement results of the transmittance T(F) of a radio wave having a frequency F (GHz) incident at an incident angle of 67.5° with respect to the window member of the example. FIG. 11 is a diagram showing the measurement results of the transmittance T(F) of a radio wave having a frequency F (GHz) incident at an incident angle of 67.5° with respect to the window member of the example.

Embodiments of the present invention will be described in detail below. Furthermore, in the following drawings, members and portions that have the same function may be described with the same reference numerals, and overlapping descriptions may be omitted or simplified. Furthermore, the embodiments shown in the drawings are schematic for clearly explaining the present invention, and do not necessarily accurately represent the size or scale of the actual product.

A window member according to an embodiment of the present invention includes a first glass plate having a thickness of 1.1 mm or more and a radio wave transmitting member facing the main surface of the first glass plate, and the radio wave transmitting member in a plan view. The transmittance T (F) of radio waves of frequency F (GHz) incident at an incident angle of 67.5° with respect to the main surface of the first glass plate is as follows in the range of 60 GHz≦F≦100 GHz. Formula (1) is satisfied.
T(F)>-0.0061×F+0.9384...(1)

When communicating with the outside through a window glass using a millimeter wave radar installed inside a car, the angle at which the radio waves are incident on the windshield surface, for example, depends on the structure of the window glass and the position of the communication partner. , differs depending on the elevation angle of the millimeter-wave radar traveling direction, etc. However, when considering the inclination angle of the windshield with respect to the horizontal plane for a typical automobile, one guideline was set to be about 67.5 degrees as the incident angle at which the millimeter wave radar enters the windshield surface. In other words, the present inventors found that the radio wave transmittance T(F) of millimeter waves incident on the window glass surface at an incident angle of 67.5° is important as an index of the millimeter wave transmittance of an automobile window glass. It has been found that an incident angle around .5° is also useful for evaluating millimeter wave transmittance. In this evaluation, the condition is that the millimeter wave radar travels in a direction parallel to the horizontal plane.
As a result of further studies by the present inventors based on the above knowledge, it has been found that a window member that satisfies the above formula (1) has a high frequency of several tens of GHz to 100 GHz, especially when used for automobile window glass. It was discovered that it has high transparency even to radio waves in the frequency band.

Note that, as described above, the window member according to the embodiment of the present invention is particularly useful as a window glass for an automobile, but the application is not particularly limited, and it may be used, for example, as a window glass for a building.

Furthermore, in order to further improve the radio wave transmittance, the window member according to the embodiment of the present invention has a region provided with the radio wave transmitting member at an angle of 67.5° with respect to the main surface of the first glass plate in plan view. It is preferable that the transmittance T (F) of a radio wave with a frequency F (GHz) incident at an incident angle of , satisfies the following formula (2) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+0.9784...(2)

Further, in order to further improve radio wave transmittance, the window member according to the embodiment of the present invention has a region provided with the radio wave transmitting member at an angle of 67.5° with respect to the main surface of the first glass plate in plan view. It is preferable that the transmittance T (F) of a radio wave having a frequency F (GHz) incident at an incident angle of , satisfies the following formula (3) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0384...(3)

Further, in order to further improve radio wave transmittance, the window member according to the embodiment of the present invention has a region provided with the radio wave transmitting member at an angle of 67.5° with respect to the main surface of the first glass plate in plan view. It is preferable that the transmittance T (F) of a radio wave having a frequency F (GHz) incident at an incident angle of , satisfies the following formula (4) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0554...(4)

In the window member according to the embodiment of the present invention, a part of the area facing the main surface of the first glass plate may be provided with a radio wave transmitting member, and the entire area facing the main surface of the first glass plate may be provided with a radio wave transmitting member. It may also include a radio wave transparent member.
Hereinafter, as first and second embodiments of the present invention, a window member in which a part of the region facing the main surface of the first glass plate includes a radio wave transmitting member, and as a third embodiment, a first glass plate will be described. Although a window member in which the entire area facing the main surface of the plate includes a radio wave transmitting member will be described, the embodiments of the present invention are not limited to those described below.

[First embodiment]
FIG. 1 is a front view of the window member 10 of the first embodiment, and FIG. 2 is a cross-sectional view of the window member 10 of the present embodiment taken along the line XX in FIG. The window member 10 of the present embodiment includes a first region A that is a region that includes the radio wave transmitting member 12 in a plan view, and a second region B that is a region that does not include the radio wave transmitting member 12 in a plan view. That is, the second region B is provided with a material different from that of the radio wave transmitting member 12. In this embodiment, the first region A is formed in a portion where high radio wave transparency is required for radio waves having a frequency of 60 GHz to 100 GHz, depending on the use of the window member 10. For example, when the window member 10 is used as a window glass for an automobile, the first area A is formed around a millimeter wave radar or the like. In this specification, evaluations such as "high/low radio wave transparency" refer to radio wave transparency for frequencies of 60 GHz to 100 GHz, unless otherwise specified.
Note that the window member 10 of this embodiment includes a second glass plate 13 that faces the main surface of the first glass plate 11 in the second region B.

In this embodiment, the total thickness of the window member 10 is preferably 3.5 mm or more and 10 mm or less, and the thickness of the radio wave transmitting member 12 and the second glass plate 13 is each 0.4 mm or more and 2.5 mm or less. The following is preferable, and 0.5 mm or more and 1.5 mm or less is more preferable. In this case, since the first glass plate 11 is thicker, cracks are less likely to occur when an object collides with the first glass plate 11, and even if a crack occurs, the distance of the crack is less likely to increase, which is preferable. Note that, unless otherwise specified, the first glass plate 11 is located on the outside of the vehicle when it is attached to the vehicle, and the radio wave transmitting member 12 and the second glass plate 13 are located on the outer side of the vehicle. It shall be located inside the vehicle.

The compositions of the first glass plate 11 and the second glass plate 13 in this embodiment are not particularly limited. For example, in terms of mole percentages based on oxides of each component, SiO ₂ is 50 to 80%, B ₂ O ₃ is 0 to 10%, Al ₂ O ₃ is 0.1 to 25%, Li ₂ O, Na ₂ A total of 3 to 30% of at least one alkali metal oxide selected from the group consisting of O and K ₂ O, 0 to 25% of MgO, 0 to 25% of CaO, 0 to 5% of SrO, and 0 to 5% of BaO. A glass plate containing 0 to 5% ZrO ₂ and 0 to 5% SnO ₂ can be used as the first glass plate 11 and the second glass plate 13.
Further, a glass plate that can be used as a radio wave transmitting member, which will be exemplified in the description of the radio wave transmitting member described later, may be used as at least one of the first glass plate 11 and the second glass plate 13. In order to obtain excellent radio wave transmittance, particularly for millimeter waves, it is preferable that the first glass plate 11 is made of glass having a composition A described later or glass having a composition C described later.
The thickness of the first glass plate 11 may be 1.1 mm or more, preferably 1.5 mm or more, and 1.8 mm or more in order to ensure strength, especially to increase resistance to flying stones, which is an indicator of strength. is more preferable. Further, the upper limit of the thickness of the first glass plate 11 is not particularly limited, but as the thickness increases, the weight also increases, so it is usually desirable to have a thickness of 3.0 mm or less.
Note that the compositions and thicknesses of the first glass plate 11 and the second glass plate 13 may be the same or different.

The material constituting the radio wave transmitting member 12 is not particularly limited as long as it can increase the radio wave transmission of a predetermined millimeter wave, but materials with a low dielectric constant or a material with a low tan δ (dielectric loss tangent; δ is a loss angle) may be used. Preferably, a material having a low dielectric loss due to a low tan δ is preferably used. Note that the dielectric loss tangent (tan δ) is a value measured at 25° C. and 28 GHz using a cavity resonator and a vector network analyzer according to a method specified in Japanese Industrial Standards (JIS R 1641:2007). For example, the following can be used as the radio wave transmitting member 12. Hereinafter, the radio wave transmitting member 12 will be explained separately into "glass material" and "material other than glass material."

(Glass material)
Examples of the material constituting the radio wave transmitting member 12 include glass, and as an example, alkali-free glass can be used. Alkali-free glass is glass in which the total content of alkaline components expressed as a molar percentage based on oxides is 1.0% or less. Further, as the alkali-free glass, glass having a total content of 0.1% or less can also be preferably used. In addition, the content of other components is not particularly limited, but for example, the content expressed as a mole percentage on an oxide basis of each component is
50%≦ _SiO2 ≦80%
0 _% ≦ _Al2O3 ≦30%
0 _% ≦ _B2O3 ≦25%
0%≦MgO≦25%
0%≦CaO≦25%
0%≦SrO≦25%
0%≦BaO≦25%
0%≦ _ZrO2 ≦5%
5%≦RO≦40% (RO represents the total amount of MgO, CaO, SrO, BaO)
It is preferable to satisfy the following.

Further, as the glass constituting the radio wave transmitting member 12, for example, glass having the composition shown below (hereinafter also referred to as "composition A", "composition B", and "composition C") can be used. Note that the glasses of composition A and composition B (composition C) may be applied not only to the radio wave transmitting member 12 but also to the first glass plate 11. Further, when glass having composition A or composition B (composition C) is applied to the first glass plate 11, glass having composition A or composition B (composition C) may be applied to the radio wave transmitting member 12. Various materials for the radio wave transmitting member that are different from glasses having composition A and composition B (composition C), which will be described later, may be used. The details of the glass of composition A and the glass of composition B (composition C) will be described below.

(Glass with composition A)
The glass of composition A is a glass in which the content of each component expressed as a molar percentage on an oxide basis satisfies the following relationship.
50≦ _SiO2 ≦85
0≦ _{Al2O3 ≦} 20
4≦R ₂ O≦22 (R ₂ O represents the total amount of alkali metal oxides)
0≦RO≦20 (RO represents the total amount of MgO, CaO, SrO, BaO)
0≦ _Na2O / _R2O ≦0.8
0≦ _K2O / _R2O ≦0.7
The glass of composition A will be explained in detail below.

The specific gravity of the glass having composition A is preferably 2.4 or more and 3.0 or less. Further, the Young's modulus of the glass having composition A is preferably 60 GPa or more and 100 GPa or less. Further, the average linear expansion coefficient of the glass of composition A from 50°C to 350°C is preferably 50x10 ^-7 /°C or more and 120x10 ^-7 /°C or less. If the glass of composition A satisfies these conditions, it can be suitably used as a window member.

The glass of composition A preferably contains a certain amount or more of SiO ₂ to ensure weather resistance, and as a result, the specific gravity of the glass of composition A can be 2.4 or more. The specific gravity of the glass of composition A is preferably 2.45 or more. Further, since the specific gravity of the glass of composition A is 3.0 or less, it is less likely to become brittle and lightweight. The specific gravity of the glass of composition A is preferably 2.6 or less.

Glass of composition A has high rigidity due to its large Young's modulus, making it more suitable for automotive window applications and the like. The Young's modulus of the glass of composition A is preferably 65 GPa or more, more preferably 70 GPa or more, even more preferably 72 GPa or more. On the other hand, if SiO ₂ is increased to increase the Young's modulus, the solubility decreases, so the appropriate Young's modulus of the glass of composition A is 100 GPa or less, preferably 85 GPa or less, and more preferably 78 GPa or less.

In addition, the glass of composition A has a large average coefficient of linear expansion, so it can be physically strengthened and can be preferably used for window members. The average linear expansion coefficient of the glass of composition A from 50° C. to 350° C. is more preferably 60×10 ⁻⁷ /° C. or more, and even more preferably 80×10 ⁻⁷ /° C. or more. On the other hand, if the average coefficient of linear expansion becomes too large, thermal stress due to the temperature distribution of the glass plate is likely to occur during the forming process, slow cooling process, or physical strengthening process, which may cause thermal cracking of the glass plate. . Furthermore, the difference in expansion between the glass plate and the support member becomes large, causing distortion, which may lead to cracking of the glass plate. The average linear expansion coefficient of the glass of composition A from 50° C. to 350° C. is more preferably 110×10 ⁻⁷ /° C. or less, and even more preferably 98×10 ⁻⁷ /° C. or less.

Further, it is preferable that the glass of composition A has a product E×α of Young's modulus E (GPa) and average coefficient of linear expansion α (×10 ⁻⁷ /° C.) of 4900 or more. When E×α is smaller than 4900 in the glass of composition A, it becomes difficult to physically strengthen the glass, and its use as an automobile glass is limited. E×α in the glass of composition A is more preferably 5,200 or more, still more preferably 5,800 or more, particularly preferably 6,200 or more. Moreover, E×α in the glass of composition A is preferably 9000 or less. If E×α in the glass of composition A is larger than 9000, residual stress caused by temperature non-uniformity during bending tends to increase, and furthermore, thermal stress caused by temperature non-uniformity also increases, causing damage during the manufacturing process. The glass plate becomes susceptible to thermal cracking. E×α in the glass of composition A is more preferably 8,600 or less, further preferably 7,900 or less, particularly preferably 7,500 or less.

Moreover, it is preferable that the glass of composition A has a T ₂ of 1750° C. or less. Further, in the glass of composition A, T ₄ is preferably 1350°C or lower, and T ₄ -T _L is preferably -50°C or higher. It is more preferable that the glass of composition A has T ₂ of 1750° C. or lower, T ₄ of 1350° C. or lower, and T ₄ −T _L of −50° C. or higher. In addition, in this specification, T ₂ represents the temperature at which the glass viscosity becomes 10 ² (dPa・s), T ₄ represents the temperature at which the glass viscosity becomes 10 ⁴ (dPa・s), and T _L represents the temperature at which the glass viscosity becomes 10 4 (dPa・s). Represents the liquidus temperature of glass.
When T ₂ or T ₄ is higher than these predetermined temperatures, it becomes difficult to manufacture large glass sheets by the float method, fusion method, roll-out method, down-draw method, or the like. _T2 is more preferably 1600°C or less, still more preferably 1500°C or less. T ₄ is preferably 1350°C or lower, more preferably 1300°C or lower, even more preferably 1250°C or lower. The lower limits of T ₂ and T ₄ are not particularly limited, but in order to maintain weather resistance and glass specific gravity, T ₂ is typically 1200° C. or higher and T ₄ is typically 800° C. or higher. T ₂ is more preferably 1300°C or higher, even more preferably 1400°C or higher. _T4 is more preferably 900°C or higher, still more preferably 1000°C or higher.

Further, in order to enable production by the float method, T ₄ -T _L is preferably -50°C or higher. If this difference is less than -50°C, devitrification will occur in the glass during glass molding, causing problems such as a decrease in the mechanical properties of the glass and a decrease in transparency, making it difficult to obtain a glass of good quality. There is a risk that it will disappear. T ₄ -T _L is more preferably 0°C or higher, even more preferably +20°C or higher.

Further, the glass of composition A preferably has a T _g of 400°C or more and 750°C or less. In addition, in this specification, _Tg represents the glass transition point of glass. If T _g is within this predetermined temperature range, glass can be bent within the range of normal manufacturing conditions. If T _g is lower than 400°C, there will be no problem with formability, but the alkali content or alkaline earth content will become too large, resulting in excessive thermal expansion of the glass, decreased weather resistance, etc. problems are more likely to occur. Furthermore, if T _g is lower than 400° C., there is a risk that the glass will devitrify in the molding temperature range and cannot be molded. T _g is more preferably 450°C or higher, further preferably 480°C or higher, particularly preferably 520°C or higher. On the other hand, if _Tg is too high, high temperatures will be required during glass bending, making manufacturing difficult. T _g is more preferably 600°C or less, still more preferably 550°C or less.

In addition, the glass of composition A has a low tan δ (dielectric loss tangent; δ is loss angle) by adjusting the composition, and as a result, it is possible to lower dielectric loss and achieve high millimeter wave radio wave transmittance. Similarly, by adjusting the composition, the dielectric constant can be adjusted, and a dielectric constant tailored to the application can be achieved.

Further, the glass of composition A has an SiO ₂ content of 50% or more and 85% or less, expressed as a molar percentage based on oxides. Moreover, the glass of composition A has an Al ₂ O ₃ content of 0% or more and 20% or less. SiO ₂ and Al ₂ O ₃ contribute to improving Young's modulus, thereby making it easier to ensure the strength required for automotive applications, architectural applications, and the like. When Al ₂ O ₃ and/or SiO ₂ are low, it becomes difficult to ensure weather resistance, and the average coefficient of linear expansion becomes too large, which may cause thermal cracking of the glass plate. Even if Al ₂ O ₃ and/or SiO ₂ are present in too much amount, the viscosity during glass melting may increase, making glass production difficult. Furthermore, if the amount of Al ₂ O ₃ is too large, the radio wave transmittance may also decrease.

The content of SiO ₂ in the glass of composition A is more preferably 65% or more, even more preferably 70% or more, and particularly preferably 72% or more. The content of SiO ₂ in the glass of composition A is more preferably 80% or less, further preferably 77% or less, and particularly preferably 75% or less.
The content of Al ₂ O ₃ in the glass of composition A is preferably 0.1% or more in order to improve weather resistance. The content of Al ₂ O ₃ in the glass of composition A is more preferably 5% or less, more preferably 1% or less, from the viewpoint of keeping T ₂ low and making the glass easy to manufacture, and from the viewpoint of improving radio wave transmittance. More preferably, it is 0.5% or less.

In order to improve the radio wave transmittance, the SiO ₂ +Al ₂ O ₃ of the glass having the composition A, that is, the total of the SiO ₂ content and the Al ₂ O ₃ content, is preferably 50% or more and 80% or less. Further, when considering keeping the temperatures T ₂ and T ₄ low to make it easier to manufacture glass, it is better to have less SiO ₂ +Al ₂ O ₃ , so 80% or less is preferable. The content of SiO ₂ +Al ₂ O ₃ is more preferably 76% or less, and even more preferably 74% or less. However, if the amount of SiO ₂ +Al ₂ O ₃ is too small, there is a risk that the weather resistance will deteriorate and the average coefficient of linear expansion may become too large. Therefore, SiO ₂ +Al ₂ O ₃ is more preferably 65% or more, and even more preferably 72% or more.

The content of B ₂ O ₃ in the glass of composition A is preferably 0% or more and 15% or less. B ₂ O ₃ may be included to improve solubility and glass strength. Moreover, B ₂ O ₃ has the effect of increasing the radio wave transmittance of millimeter waves. On the other hand, if the content of B ₂ O ₃ is too large, the alkali element will easily volatilize during melting and molding, and there is a risk that the glass quality will deteriorate. Moreover, if the content of B ₂ O ₃ is too large, the average coefficient of linear expansion becomes small and physical strengthening becomes difficult. The content of B ₂ O ₃ is more preferably 10% or less, even more preferably 3% or less, and particularly preferably substantially free of B ₂ O ₃ . Note that when glass "substantially does not contain" a certain component, it means that the component is not actively added unless it is unavoidably mixed in as an impurity.

The content of MgO in the glass of composition A is preferably 0% or more and 20% or less. MgO is a component that promotes dissolution of glass raw materials and improves weather resistance. The content of MgO is more preferably 0.1% or more. If the MgO content is 20% or less, devitrification will hardly occur. Furthermore, MgO can be expected to have the effect of increasing the radio wave transmittance of millimeter waves. The content of MgO is more preferably 10% or less, further preferably 7% or less, even more preferably 4% or less, particularly preferably 1% or less, and most preferably 0.2% or less.

The glass of composition A may contain a certain amount of CaO, SrO, and/or BaO to reduce the amount of dielectric loss of the glass. The content of CaO is preferably 0% or more and 20% or less. The content of SrO is preferably 0% or more and 15% or less. The content of BaO is preferably 0% or more and 15% or less. When CaO, SrO, and/or BaO are included in the glass of composition A, the solubility of the glass can also be improved. The CaO content is more preferably 3% or more, which reduces the dielectric loss of the glass and improves the millimeter wave transmittance. Further, by adding 3% or more of CaO, the solubility of the glass may be improved (reduction in T ₂ and reduction in T ₄ ). The CaO content is more preferably 5% or more, further preferably 7% or more, even more preferably 8% or more, even more preferably 9% or more, and most preferably 11% or more. By setting the CaO content to 20% or less, the SrO content to 15% or less, and the BaO content to 15% or less, an increase in the specific gravity of the glass can be avoided and low brittleness and strength can be maintained. In order to prevent the glass from becoming brittle, the content of CaO is more preferably 15% or less, and even more preferably 12% or less. The content of SrO is more preferably 3% or less, and even more preferably substantially free. The content of BaO is more preferably 3% or less, and even more preferably substantially free.

In this specification, "RO" represents the total content of MgO, CaO, SrO, and BaO. The glass of composition A has an RO of 0% or more and 20% or less. If RO is 20% or less, weather resistance will improve. The RO in the glass of composition A is more preferably 16% or less, even more preferably 13% or less.
Further, from the viewpoint of lowering the temperatures T ₂ and T ₄ during manufacturing or increasing the Young's modulus, the RO of the glass of composition A is preferably more than 0%, more preferably 5% or more, and even more preferably 10% or more. preferable.

The content of Na ₂ O in the glass of composition A is preferably 0% or more and 18% or less. Na ₂ O and K ₂ O are components that improve the solubility of glass, and it is more preferable to contain either or both of them in an amount of 0.1% or more. This makes it easier to suppress T ₂ to 1750°C or less and T ₄ to 1350°C or less. Further, by incorporating Na ₂ O into the glass of composition A, chemical strengthening becomes possible. The content of Na ₂ O is more preferably 4% or more, and still more preferably 6% or more.
On the other hand, if there is too much Na ₂ O, the average coefficient of linear expansion will become too large and the glass plate will be susceptible to thermal cracking. The content of Na ₂ O is more preferably 16% or less, still more preferably 10% or less, particularly preferably 8% or less.

The content of K ₂ O in the glass of composition A is preferably 0% or more and 18% or less. K ₂ O is a component that improves the solubility of glass, and is preferably contained in an amount of 0.1% or more. This makes it easier to suppress T ₂ to 1750°C or less and T ₄ to 1350°C or less. The content of K ₂ O is more preferably 2% or more, and still more preferably 5% or more.
On the other hand, if the content of K ₂ O is too large, the average coefficient of linear expansion becomes too large and the glass plate becomes susceptible to thermal cracking. If the content of K ₂ O exceeds 18%, weather resistance decreases, which is not preferable. The content of K ₂ O is more preferably 12% or less, and even more preferably 8% or less.
Glass of composition A is more preferable because it can improve weather resistance while maintaining solubility by containing both Na ₂ O and K ₂ O. Furthermore, it can also improve the radio wave transmittance of millimeter waves. It may be effective. If the content of Na ₂ O and/or K ₂ O is small, the average coefficient of linear expansion of the glass cannot be increased, and there is a possibility that thermal strengthening cannot be performed. By setting the content of Na ₂ O and/or K ₂ O to the above-mentioned predetermined amount, the glass of composition A can be used as a window material with good compatibility with other members. Further, the glass of composition A can obtain high millimeter wave radio wave transmittance by setting the content of Na ₂ O and/or K ₂ O within the above range.

Moreover, the content of Li ₂ O in the glass of composition A is preferably 0% or more and 18% or less. Li ₂ O is a component that improves the solubility of glass, and also facilitates increasing Young's modulus and contributes to improving the strength of glass. By incorporating Li ₂ O into the glass of composition A, chemical strengthening becomes possible. Furthermore, the effect of increasing the radio wave transmittance of millimeter waves can also be produced. When Li ₂ O is contained, it may be 0.1% or more, more preferably 1% or more, and 3% or more.
On the other hand, if the content of Li ₂ O is too large, devitrification or phase separation may occur during glass production, which may make production difficult. The content of Li ₂ O is more preferably 10% or less. Further, it is not preferable to contain too much Li ₂ O as glass for automobile windows, since the thermal expansion coefficient may be lowered and physical strengthening may not be possible. Therefore, the content of Li ₂ O in the glass of composition A is more preferably 7% or less, still more preferably 3% or less, and it is particularly preferable that it is substantially not contained.

Moreover, in this specification, "R ₂ O" represents the total amount of alkali metal oxides. This usually means the sum of the contents of Li ₂ O, Na ₂ O and K ₂ O. The R ₂ O of the glass of composition A is 4% or more and 22% or less. If R ₂ O in the glass of composition A is 22% or less, weather resistance will be improved. The R ₂ O of the glass of composition A is more preferably 20% or less, still more preferably 18% or less, even more preferably 17% or less, particularly preferably 15% or less.
Further, from the viewpoint of lowering the temperatures T ₂ and T ₄ during manufacturing, R ₂ O in the glass of composition A is set to 4% or more. R ₂ O in the glass of composition A is more preferably 9% or more, still more preferably 13% or more, particularly preferably 14% or more.

Na ₂ O/R ₂ O in the glass of composition A is set to be 0 or more and 0.8 or less in order to increase the radio wave transmittance of millimeter waves. If Na ₂ O/R ₂ O is too small or too large, there is a possibility that the effect of increasing the radio wave transmittance of millimeter waves cannot be sufficiently obtained. The lower limit of Na ₂ O/R ₂ O in the glass of composition A, when containing Li ₂ O, is more preferably 0.1 or more, and even more preferably 0.3 or more. Further, when the glass of composition A does not contain Li ₂ O, the lower limit of Na ₂ O/R ₂ O is preferably slightly larger than that when it contains Li ₂ O, preferably 0.01 or more, and more preferably is 0.2 or more, more preferably 0.4 or more.
The upper limit of Na ₂ O/R ₂ O in the glass of composition A, when containing Li ₂ O, is preferably 0.8 or less, more preferably 0.6 or less, still more preferably 0.4 or less. Further, when the glass of composition A does not contain Li ₂ O, the upper limit of Na ₂ O/R ₂ O is preferably slightly larger than that when it contains Li ₂ O, preferably 0.8 or less, and more preferably is 0.7 or less, more preferably 0.55 or less.

K ₂ O/R ₂ O in the glass of composition A is set to 0 or more and 0.7 or less in order to increase the radio wave transmittance of millimeter waves. If K ₂ O/R ₂ O is too small or too large, there is a possibility that the effect of increasing the radio wave transmittance of millimeter waves cannot be sufficiently obtained. The lower limit of K ₂ O/R ₂ O in the glass of composition A, when containing Li ₂ O, is more preferably 0.1 or more, and even more preferably 0.3 or more. Further, when the glass of composition A does not contain Li ₂ O, the lower limit of K ₂ O/R ₂ O is preferably slightly larger than that when it contains Li ₂ O, preferably 0.01 or more, and more preferably is 0.2 or more, more preferably 0.4 or more.
The upper limit of K ₂ O/R ₂ O in the glass of composition A, when containing Li ₂ O, is preferably 0.7 or less, more preferably 0.6 or less, still more preferably 0.4 or less. Further, when the glass of composition A does not contain Li ₂ O, the upper limit of K ₂ O/R ₂ O is preferably slightly larger than that when it contains Li ₂ O, preferably 0.7 or less, and more preferably is 0.6 or less.

Moreover, the content of Fe ₂ O ₃ in the glass of composition A is preferably 0.001% or more and 5% or less. If the content of Fe ₂ O ₃ in the glass of composition A is less than 0.001%, there is a risk that it cannot be used for applications requiring heat shielding properties. It may be necessary to use less expensive raw materials. Furthermore, if the content of Fe ₂ O ₃ in the glass of composition A is less than 0.001%, thermal radiation may reach the bottom of the melting furnace more than necessary during glass melting, and there is a risk that a load will be applied to the melting furnace. be. The content of Fe ₂ O ₃ in the glass of composition A is more preferably 0.01% or more, still more preferably 0.05% or more.
On the other hand, if the content of Fe ₂ O ₃ in the glass of composition A exceeds 5%, heat transfer by radiation may be hindered during production, making it difficult to melt the raw materials. Furthermore, if the content of Fe ₂ O ₃ in the glass of composition A becomes too large, the light transmittance in the visible range will decrease, so there is a possibility that the glass will not be suitable for use in automobile windows. The content of Fe ₂ O ₃ in the glass of composition A is more preferably 1% or less, even more preferably 0.3% or less.

Further, the content of TiO ₂ in the glass of composition A is preferably 0.001% or more and 5% or less. For example, if the glass of composition A does not contain TiO ₂ , there is a risk that a bubble layer will be generated on the surface of the molten glass during the production of a glass plate, but if the bubble layer is generated, the temperature of the molten glass will not rise; It becomes difficult to clarify and tends to reduce productivity. Therefore, in order to thin or eliminate the foam layer generated on the surface of the molten glass, a titanium compound may be supplied as an antifoaming agent to the foam layer generated on the surface of the molten glass. The titanium compound is incorporated into the molten glass and exists as TiO ₂ . The content of TiO ₂ in the glass in composition A is more preferably 0.05% or more. Furthermore, since TiO ₂ absorbs light in the ultraviolet region, it is preferable to add it if it is desired to block ultraviolet light. The content of TiO ₂ in that case may be preferably 0.1% or more, and further may be 0.5% or more. However, if the content of TiO ₂ is too large, the liquidus temperature may rise and devitrification may occur. In addition, since it absorbs light in the visible range and may cause yellow coloration, the content of TiO ₂ in the glass of composition A is preferably 5% or less, more preferably 0.5% or less, More preferably, it is 0.2% or less.

If moisture is present in the glass of composition A, it absorbs light in the near-infrared region, so the transmittance of light in the near-infrared region decreases, making it difficult to use infrared irradiation equipment (laser radar, etc.) Not suitable for Here, the water content in the glass can generally be expressed as a β-OH value. The β-OH value of the glass of composition A is preferably 0.5 mm ⁻¹ or less, more preferably 0.4 mm ⁻¹ or less, even more preferably 0.3 mm ⁻¹ or less, and particularly preferably 0.2 mm ⁻¹ or less. β-OH is obtained from the transmittance of glass measured using FT-IR (Fourier transform infrared spectrophotometer) using the following formula.
β-OH=(1/X)log ₁₀ (T _A /T _B ) [mm ^-1 ]
X: Thickness of sample [mm]
T _A : Transmittance at reference wave number 4000 cm ^-1 [%]
T _B : Minimum transmittance near hydroxyl group absorption wave number 3600 cm ^-1 [%]

The glass of composition A absorbs light in the near-infrared region when moisture is present in the glass as described above. Therefore, in order to improve heat shielding properties, the glass of composition A preferably has a β-OH value of 0.05 mm ^-1 or more, more preferably 0.10 mm ^-1 or more, and even more preferably 0.15 mm ^{-1 or} more.

(Glass with composition B and composition C)
In addition, the first glass plate 11 and/or the radio wave transmitting member 12 has a total content of SiO ₂ , B ₂ O ₃ , and Al ₂ O ₃ expressed as a mole percentage based on oxides of each component. You may use the glass of "composition B" which is 72% or more. By using the glass of "composition B" for the first glass plate 11, it is easy to ensure glass strength, and in particular, resistance to flying stones is improved, which is preferable. Further, it is preferable to use glass having composition B for the first glass plate 11 because it is possible to maintain high millimeter wave radio wave transmittance.

In this case, the radio wave transmitting member 12 and the second glass plate 13 may be the same glass plate (composition B). The second glass plate 13 may have the same glass composition as the first glass plate 11 (=composition B) as long as the desired millimeter wave radio wave transmittance is obtained. Note that if the second glass plate 13 is subjected to chemical strengthening treatment, higher strength can be obtained.

Further, as the glass of composition B, a glass (also referred to as "composition C") in which the content of each component expressed in mole percentage on an oxide basis satisfies the following relationship is more preferable.
72≦SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ≦98
55≦ _SiO2 ≦87
0≦ _{Al2O3 ≦} 20
0≦ _{B2O3 ≦} 25
0≦R ₂ O ≦ 5 (R ₂ O represents the total amount of alkali metal oxide)
0≦RO≦20 (RO represents the total amount of MgO, CaO, SrO, BaO)
A more preferable composition range for the glass having composition C will be described in detail below.

As described above, the glass of composition C has a content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ of 72% or more and 98% or less. If the content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ is less than 72%, the network components constituting the glass will decrease, making the glass more likely to crack. Furthermore, there is a possibility that the distance of the generated cracks tends to increase. Furthermore, the radio wave transmittance of millimeter waves may also decrease. The content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ in the glass of composition C is preferably 78% or more, more preferably 83% or more, even more preferably 86% or more, even more preferably 89% or more, and 92% The above is particularly preferable. On the other hand, if the network component increases too much, the temperature at which the glass is melted or the glass is formed becomes high, which may make it difficult to manufacture a glass plate. Therefore, the content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ in the glass of composition C is preferably 97% or less, more preferably 96% or less, even more preferably 95% or less, and even more preferably 94% or less.

The content of SiO ₂ in the glass of composition C is preferably 55% or more, from the viewpoint of improving the radio wave transmittance of millimeter waves, suppressing the generation of cracks in the glass, and making it difficult to extend the distance of the cracks that occur. % or more, more preferably 63% or more, even more preferably 66% or more, particularly preferably 67% or more. On the other hand, if the content of SiO ₂ in the glass of composition C becomes too large, the temperature becomes high enough to melt the glass or mold the glass, which may make it difficult to manufacture a glass plate. Therefore, the content of SiO ₂ in the glass of composition C is preferably 87% or less, more preferably 80% or less, further preferably 75% or less, even more preferably 70% or less, and particularly preferably 69% or less.

The glass of composition C may contain Al ₂ O ₃ to improve weather resistance. When the glass of composition C contains Al ₂ O ₃ , the content of Al ₂ O ₃ is preferably 5% or more, more preferably 8% or more, even more preferably 9% or more, and even more preferably 10% or more. , 11% or more is particularly preferred. On the other hand, if the content of Al ₂ O ₃ in the glass of composition C is too high, there is a risk that the millimeter wave radio wave transmittance will decrease and devitrification will occur easily. Therefore, the content of Al ₂ O ₃ in the glass of composition C is preferably 20% or less, more preferably 18% or less, even more preferably 16% or less, even more preferably 14% or less, and particularly preferably 13% or less. , 12% or less is most preferred.

The glass of composition C may contain B ₂ O ₃ to improve solubility, glass strength, and millimeter wave radio transmittance. When the glass of composition C contains B ₂ O ₃ , the content of B ₂ O ₃ is preferably more than 0% and 25% or less. On the other hand, in the glass of composition C, if the content of B ₂ O ₃ is too large, the alkali element will easily volatilize during melting and molding, which may lead to a decrease in the quality of the glass. Therefore, the content of B ₂ O ₃ in the glass of composition C is more preferably 23% or less, more preferably 21% or less, even more preferably 20% or less, even more preferably 19% or less, and especially 18% or less. preferable. The content of B ₂ O ₃ in the glass of composition C is preferably 7% or more, more preferably 10% or more, even more preferably 12% or more, even more preferably 14% or more, and particularly preferably 16% or more. .

Further, in order to improve the radio wave transmittance of millimeter waves, the SiO ₂ +Al ₂ O ₃ of the glass having the composition C, that is, the total of the SiO ₂ content and the Al ₂ O ₃ content is preferably 65% or more and 85% or less. In order to increase the radio wave transmittance of millimeter waves and to further consider keeping the temperatures T ₂ and T ₄ low to facilitate glass production, it is better to have less SiO ₂ +Al ₂ O ₃ , preferably 80% or less. SiO ₂ +Al ₂ O ₃ in the glass of composition C is more preferably 78% or less, even more preferably 76% or less, particularly preferably 74% or less, even more preferably 72% or less, and most preferably 71% or less. However, if SiO ₂ +Al ₂ O ₃ in the glass of composition C is too small, there is a risk that the weather resistance will decrease and the average linear expansion coefficient may become too large. Therefore, SiO ₂ +Al ₂ O ₃ in the glass of composition C is more preferably 68% or more, and even more preferably 70% or more.

The glass of composition C preferably has a value of Al ₂ O ₃ /B ₂ O ₃ of 0.35 or less. It is preferable that the value of Al ₂ O ₃ /B ₂ O ₃ in the glass of composition C is 0.35 or less because the millimeter wave radio transmittance can be further increased. Furthermore, if the value of Al ₂ O ₃ /B ₂ O ₃ in the glass of composition C is 0.35 or less, it becomes easier to melt the glass, so the viscosity of the glass during manufacturing can be lowered, and T ₂ can be lowered. It becomes easier to suppress _T4 to 1,350°C or less. The value of Al ₂ O ₃ /B ₂ O ₃ in the glass of composition C is more preferably 0.3 or less, particularly preferably 0.28 or less.

Further, it is preferable that the glass of composition C has R ₂ O, which represents the total amount of alkali metal oxides, of 5% or less, since it is possible to increase the radio wave transmittance of millimeter waves and to expect improvement in weather resistance. R ₂ O in the glass of composition C is preferably 4% or less, more preferably 3% or less, even more preferably 2% or less, even more preferably 1% or less, and particularly preferably 0.5% or less. Further, the glass of composition C may contain a small amount of R ₂ O from the viewpoint of lowering the temperatures T ₂ and T ₄ during manufacture or to facilitate heating by directly applying electricity to the glass melt. In that case, the content of R ₂ O is preferably 0.001% or more, more preferably 0.005% or more, even more preferably 0.007% or more, even more preferably 0.01% or more, and 0.02% or more. % or more is particularly preferable, and 0.03% or more is most preferable. On the other hand, in the glass of composition C, if the R ₂ O content is too high, the millimeter wave radio transmittance may decrease, so R ₂ O is preferably 0.4% or less, and 0.3% or less. It is more preferably at most 0.2%, even more preferably at most 0.1%, particularly preferably at most 0.08%, and most preferably at most 0.06%.

Moreover, the content of Na ₂ O in the glass of composition C is more preferably 0% or more and 4% or less. Na ₂ O and K ₂ O are components that improve the solubility of glass, and it is more preferable to contain either or both of them in an amount of 0.001% or more. The content of Na ₂ O in the glass of composition C is more preferably 0.005% or more, particularly preferably 0.01% or more, even more preferably 0.02% or more, and most preferably 0.01% or more. 0.03% or more.
On the other hand, if the glass of composition C contains too much Na ₂ O, there is a risk that the millimeter wave radio transmittance will decrease. The content of Na ₂ O in the glass of composition C is more preferably 3% or less, particularly preferably 2% or less, even more preferably 1% or less, and most preferably 0.5% or less.

Moreover, the content of K ₂ O in the glass of composition C is more preferably 0% or more and 4% or less. Na ₂ O and K ₂ O in the glass of composition C are components that improve the solubility of the glass, and it is more preferable to contain either or both of them in an amount of 0.001% or more. The content of K ₂ O in the glass of composition C is more preferably 0.005% or more, particularly preferably 0.01% or more, even more preferably 0.02% or more, and most preferably 0.01% or more. 0.03% or more.
On the other hand, if too much K ₂ O is present in the glass having composition C, the radio wave transmittance may decrease. The content of K ₂ O in the glass of composition C is more preferably 3% or less, particularly preferably 2% or less, even more preferably 1% or less, and most preferably 0.5% or less.
Glass with composition C is more preferable because it can improve weather resistance while maintaining solubility by containing both Na ₂ O and K ₂ O, and is also effective in increasing radio wave transmittance. There are cases. By setting the content of Na ₂ O and/or K ₂ O to the above-mentioned predetermined amount, the glass of composition C can be used as a window material with good compatibility with other members. Further, the glass having composition C can obtain high millimeter wave radio wave transmittance by setting the content of Na ₂ O and/or K ₂ O within the above range.

Moreover, the content of Li ₂ O in the glass of composition C is preferably 0% or more and 5% or less. Li ₂ O is a component that improves the solubility of glass, and also facilitates increasing Young's modulus and contributes to improving the strength of glass. Furthermore, the effect of increasing the radio wave transmittance of millimeter waves can also be produced. When Li ₂ O is contained in the glass of composition C, the content may be at least 0.001%, more preferably at least 0.002%, and preferably at least 0.003%.
On the other hand, if the content of Li ₂ O in the glass of composition C is too large, devitrification or phase separation may occur during glass production, which may make production difficult. Therefore, the Li ₂ O content in the glass of composition C is more preferably 3% or less, further preferably 1% or less, particularly preferably 0.5% or less, and even more preferably 0.1%. or less, and most preferably substantially no content.

Na ₂ O/R ₂ O in the glass of composition C is more preferably 0 or more and 0.9 or less in order to increase the radio wave transmittance of millimeter waves. If Na ₂ O/R ₂ O is too small or too large in the glass of composition C, there is a possibility that the effect of increasing the radio wave transmittance of millimeter waves cannot be sufficiently obtained. The lower limit of Na ₂ O/R ₂ O in the glass of composition C, when containing Li ₂ O, is more preferably 0.1 or more, and even more preferably 0.3 or more. On the other hand, when the glass of composition C does not contain Li ₂ O, the lower limit of Na ₂ O/R ₂ O should be slightly larger than that when it contains Li ₂ O, preferably 0.01 or more, or more. Preferably it is 0.2 or more, more preferably 0.4 or more.
The upper limit of Na ₂ O/R ₂ O in the glass of composition C, when containing Li ₂ O, is preferably 0.8 or less, more preferably 0.6 or less, still more preferably 0.4 or less. When the glass of composition C does not contain Li ₂ O, the upper limit of Na ₂ O/R ₂ O should be slightly larger than when it contains Li ₂ O, preferably 0.8 or less, more preferably It is 0.7 or less, more preferably 0.6 or less.

K ₂ O/R ₂ O in the glass of composition C is more preferably 0 or more and 0.7 or less in order to increase the radio wave transmittance of millimeter waves. If K ₂ O/R ₂ O is too small or too large in the glass of composition C, there is a possibility that the effect of increasing the radio wave transmittance of millimeter waves cannot be sufficiently obtained. The lower limit of K ₂ O/R ₂ O in the glass of composition C, when containing Li ₂ O, is more preferably 0.1 or more, still more preferably 0.3 or more. On the other hand, when the glass of composition C does not contain Li ₂ O, the lower limit of K ₂ O/R ₂ O should be slightly larger than that when it contains Li ₂ O, preferably 0.01 or more, or more. Preferably it is 0.2 or more, more preferably 0.4 or more.
The upper limit of K ₂ O/R ₂ O in the glass of composition C, when containing Li ₂ O, is preferably 0.7 or less, more preferably 0.6 or less, still more preferably 0.4 or less. When the glass of composition C does not contain Li ₂ O, the upper limit of K ₂ O/R ₂ O should be slightly larger than when it contains Li ₂ O, preferably 0.7 or less, more preferably It is 0.6 or less.

Further, the glass of composition C may contain RO, which represents the total content of MgO, CaO, SrO, and BaO, in order to improve weather resistance and suppress devitrification and phase separation during glass plate production. The content of RO in the glass of composition C is preferably 1% or more, more preferably 2% or more, even more preferably 3% or more, even more preferably 3.5% or more, and particularly preferably 4% or more. On the other hand, in glass with composition C, if the RO content is too high, devitrification may easily occur, and there is also a risk that millimeter wave radio transmittance may decrease, so the RO content should be 20% or less. preferable. The content of RO in the glass of composition C is preferably 17% or less, more preferably 14% or less, even more preferably 11% or less, even more preferably 8% or less, and particularly preferably 6% or less.

The content of MgO in the glass of composition C is more preferably 0% or more and 10% or less. MgO is a component that promotes dissolution of glass raw materials and improves weather resistance. The content of MgO in the glass of composition C is more preferably 0.1% or more. When the content of MgO in the glass of composition C is 10% or less, devitrification is less likely to occur. Furthermore, if there is too much MgO in the glass of composition C, there is a risk that the millimeter wave radio transmittance will decrease, so the MgO content is more preferably 3% or less, particularly preferably 1% or less, and 0.6% or less. The following is more preferable, and 0.3% or less is particularly preferable.

The glass of composition C may contain a certain amount of CaO, SrO, and/or BaO to reduce the amount of dielectric loss of the glass. The content of CaO in the glass of composition C is more preferably 0% or more and 10% or less. The content of SrO in the glass of composition C is preferably 0% or more and 10% or less. The BaO content in the glass of composition C is preferably 0% or more and 10% or less. When the glass of composition C contains CaO, SrO, and/or BaO, the solubility of the glass can also be improved. The CaO content in the glass of composition C is more preferably 0.1% or more, which reduces the dielectric loss of the glass and improves the millimeter wave transmittance. Further, by adding 3% or more of CaO to the glass of composition C, the solubility of the glass may be improved (reduction in T ₂ and reduction in T ₄ ). The content of CaO in the glass of composition C is more preferably 4% or more, and even more preferably 5% or more. In addition, by setting the CaO content to 10% or less, the SrO content to 10% or less, and the BaO content to 10% or less in the glass of composition C, an increase in the specific gravity of the glass can be avoided, resulting in low brittleness. and strength is maintained. In order to prevent the glass from becoming brittle, the content of CaO in the glass of composition C is more preferably 8% or less, and even more preferably 6% or less. Further, the content of SrO in the glass of composition C is more preferably 7% or less, further preferably 4% or less, even more preferably 1% or less, and most preferably 0.5% or less. Further, the content of BaO in the glass of composition C is more preferably 3% or less, further preferably 2% or less, particularly preferably 1% or less, and even more preferably substantially not contained.

Moreover, the content of Fe ₂ O ₃ in the glass of composition C is preferably 0.001% or more and 5% or less. If the content of Fe ₂ O ₃ in the glass of composition C is less than 0.001%, there is a risk that it cannot be used for applications that require heat shielding properties. It may be necessary to use less expensive raw materials. Furthermore, if the content of Fe ₂ O ₃ in the glass of composition C is less than 0.001%, there is a risk that more heat radiation will reach the bottom of the melting furnace than necessary during glass melting, and a load will be applied to the melting furnace. . The content of Fe ₂ O ₃ in the glass of composition C is more preferably 0.01% or more, still more preferably 0.05% or more.
On the other hand, if the content of Fe ₂ O ₃ in the glass of composition C exceeds 5%, there is a possibility that heat transfer by radiation is hindered during production, making it difficult to melt the raw materials. Furthermore, if the content of Fe ₂ O ₃ in the glass of composition C becomes too large, the light transmittance in the visible range will decrease, so there is a possibility that the glass will not be suitable for use in automobile windows. The content of Fe ₂ O ₃ in the glass of composition C is more preferably 1% or less, still more preferably 0.3% or less.

Moreover, the content of TiO ₂ in the glass of composition C is preferably 0.001% or more and 5% or less. For example, if TiO ₂ is not contained, there is a risk that a bubble layer will be formed on the surface of the molten glass during the production of glass plates, but if the bubble layer is formed, the temperature of the molten glass will not rise and it will be difficult to clarify. It tends to reduce productivity. Therefore, in order to thin or eliminate the foam layer generated on the surface of the molten glass, a titanium compound may be supplied as an antifoaming agent to the foam layer generated on the surface of the molten glass. The titanium compound is incorporated into the molten glass and exists as TiO ₂ . The TiO ₂ content of the glass in composition C is preferably 0.01% or more, more preferably 0.02% or more, and even more preferably 0.03% or more. Furthermore, since TiO ₂ absorbs light in the ultraviolet region, it may be added when blocking ultraviolet light. In that case, the content of TiO ₂ in the glass of composition C may be preferably 0.1% or more, and further may be 0.5% or more. However, if the content of TiO ₂ in the glass of composition C is too large, the liquidus temperature may rise and devitrification may occur. In addition, absorption of light in the visible range may occur, causing yellow coloration, so it is preferable to keep the content of TiO ₂ in the glass of composition C at 5% or less, and 0.5% or less. It is more preferably 0.2% or less.

In addition, the glass of composition C has a low tan δ (dielectric loss tangent; δ is a loss angle) by adjusting the composition, and as a result, it is possible to lower the dielectric loss and achieve high millimeter wave radio wave transmittance. Similarly, by adjusting the composition, the dielectric constant can be adjusted, and a dielectric constant tailored to the application can be achieved.

Glass with composition C absorbs light in the near-infrared region when moisture is present in the glass, so the transmittance of light in the near-infrared region decreases, making it difficult to use infrared irradiation equipment (laser radar, etc.) Not suitable for Here, the water content in the glass can generally be expressed as a β-OH value. The β-OH value of the glass of composition C is preferably 0.5 mm ⁻¹ or less, more preferably 0.4 mm ⁻¹ or less, even more preferably 0.3 mm ⁻¹ or less, and particularly preferably 0.2 mm ⁻¹ or less. β-OH is obtained from the transmittance of glass measured using FT-IR (Fourier transform infrared spectrophotometer) using the following formula.
β-OH=(1/X)log ₁₀ (T _A /T _B ) [mm ^-1 ]
X: Thickness of sample [mm]
T _A : Transmittance at reference wave number 4000 cm ^-1 [%]
T _B : Minimum transmittance near hydroxyl group absorption wave number 3600 cm ^-1 [%]

The glass of composition C absorbs light in the near-infrared region when moisture is present in the glass as described above. Therefore, in order to improve the heat shielding properties of the glass having composition C, the β-OH value is preferably 0.05 mm ^-1 or more, more preferably 0.10 mm ^-1 or more, and even more preferably 0.15 mm ^{-1 or} more.

The specific gravity of the glass having composition C is preferably 2.1 or more and 2.8 or less. Further, the Young's modulus of the glass having composition C is preferably 50 GPa or more and 90 GPa or less. Further, the average linear expansion coefficient of the glass having composition C from 50°C to 350°C is preferably 30×10 ⁻⁷ /°C or more and 50×10 ⁻⁷ /°C or less. If the glass of composition C satisfies these conditions, it can be suitably used as a window member.

The glass of composition C preferably contains a certain amount or more of SiO ₂ to ensure weather resistance, and as a result, the specific gravity of the glass of composition C can be 2.1 or more. The specific gravity of the glass of composition C is preferably 2.2 or more. When the specific gravity of the glass of composition C is 2.8 or less, it is less likely to become brittle and lightweight. The specific gravity of the glass of composition C is more preferably 2.6 or less, particularly preferably 2.5 or less, even more preferably 2.4 or less, and most preferably 2.3 or less.

Glass with composition C has a high Young's modulus and thus has high rigidity, making it more suitable for automotive window applications and the like. The Young's modulus of the glass of composition C is preferably 50 GPa or more, more preferably 52 GPa or more, even more preferably 54 GPa or more, particularly preferably 56 GPa or more, even more preferably 57 GPa or more, and most preferably 58 GPa or more. On the other hand, in order to suppress thermal cracking of the glass plate, the Young's modulus should be lower, and the appropriate Young's modulus for the glass of composition C is 80 GPa or less, preferably 75 GPa or less, more preferably 70 GPa or less, and particularly preferably It is 65 GPa or less, more preferably 63 GPa or less, most preferably 62 GPa or less.

Further, the glass having composition C is preferable because by reducing the average coefficient of linear expansion, the generation of thermal stress due to the temperature distribution of the glass plate is suppressed, and thermal cracking of the glass plate becomes less likely to occur. The average linear expansion coefficient of the glass of composition C from 50° C. to 350° C. is more preferably 30×10 ⁻⁷ /° C. or more, and even more preferably 31×10 ⁻⁷ /° C. or more. On the other hand, if the average coefficient of linear expansion becomes too large, thermal stress due to the temperature distribution of the glass plate is likely to occur during the forming process, slow cooling process, or physical strengthening process, which may cause thermal cracking of the glass plate. . Furthermore, the difference in expansion between the glass plate and the supporting member becomes large, causing distortion, which may lead to cracking of the glass plate. The average linear expansion coefficient of the glass having composition C from 50°C to 350°C is more preferably 45×10 ^-7 /°C or less, even more preferably 40×10 ^-7 /°C or less, particularly preferably 36×10 ^-7 /°C or less, even more preferably 34×10 ⁻⁷ /°C or less, and most preferably 32×10 ⁻⁷ /°C or less.

Further, the glass having composition C preferably has a product E×α of Young's modulus E (GPa) and average linear expansion coefficient α (×10 ⁻⁷ /° C.) of 1500 or more. When Exα is smaller than 1500 in the glass of composition C, it becomes difficult to obtain rigidity as a window glass, and its use as an automobile glass is limited. E×α in the glass of composition C is more preferably 1,600 or more, still more preferably 1,700 or more. Moreover, E×α in the glass of composition C is preferably 3000 or less. If E×α in the glass of composition C is larger than 3000, residual stress caused by temperature non-uniformity during bending tends to increase, and furthermore, thermal stress caused by temperature non-uniformity also becomes large, causing damage during the manufacturing process. The glass plate becomes susceptible to thermal cracking. E×α in the glass of composition C is more preferably 3,000 or less, further preferably 2,500 or less, particularly preferably 2,200 or less, even more preferably 2,000 or less, and most preferably 1,800 or less.

Moreover, it is preferable that the glass of composition C has a T ₂ of 1750° C. or less. Moreover, it is preferable that the glass of composition C has a T ₄ of 1350° C. or less. Further, it is preferable that the glass having composition C has a T ₄ -T _L of -50°C or higher. In this specification, T ₂ represents the temperature at which the glass viscosity becomes 10 ² (dPa・s), T ₄ represents the temperature at which the glass viscosity becomes 10 ⁴ (dPa・s), and T _L represents the temperature at which the glass viscosity becomes 10 4 (dPa・s). Represents liquidus temperature.
If T ₂ or T ₄ exceeds these predetermined temperatures, it becomes difficult to manufacture large plates by the float method, fusion method, roll-out method, down-draw method, or the like. T ₂ is more preferably 1700°C or less, even more preferably 1670°C or less. T ₄ is preferably 1350°C or lower, more preferably 1300°C or lower, even more preferably 1250°C or lower. The lower limits of T ₂ and T ₄ are not particularly limited, but in order to maintain weather resistance and glass specific gravity, T ₂ is typically 1500° C. or higher and T ₄ is typically 1100° C. or higher. T ₂ is more preferably 1550°C or higher, even more preferably 1600°C or higher. _T4 is more preferably 1150°C or higher, even more preferably 1200°C or higher.

Further, in order to enable production by the float method, T ₄ -T _L is preferably -50°C or higher. If this difference is smaller than -50°C, devitrification will occur in the glass during glass molding, causing problems such as a decrease in the mechanical properties of the glass and a decrease in transparency, making it difficult to obtain a glass of good quality. There is a risk that it will disappear. T ₄ -T _L is more preferably 0°C or higher, even more preferably +20°C or higher.

Further, the glass having composition C preferably has a T _g of 550°C or more and 750°C or less. If T _g is within this predetermined temperature range, glass can be bent within normal manufacturing conditions. If T _g is lower than 550° C., there will be no problem with moldability, but problems such as decreased weather resistance will likely occur. Furthermore, if T _g is lower than 550° C., there is a risk that the glass will devitrify in the molding temperature range and cannot be molded. T _g is more preferably 600°C or higher, further preferably 620°C or higher, particularly preferably 640°C or higher. On the other hand, if T _g is too high, high temperatures will be required during glass bending, making manufacturing difficult. T _g is more preferably 700°C or less, further preferably 650°C or less, particularly preferably 630°C or less.

The glass plate according to the present embodiment preferably has a NiO content of 0.01% or less in any of the above embodiments, that is, the glass of composition A, the glass of composition B, and the glass of composition C. The glass plate according to the present embodiment contains a total of components other than SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , R ₂ O, RO, TiO ₂ , and Fe ₂ O ₃ (hereinafter also referred to as “other components”). Preferably, the amount is 5% or less. Other components include, for example, ZrO ₂ , Y ₂ O ₃ , Nd ₂ O ₅ , P ₂ O ₅ , GaO _{2 , GeO 2} , CeO ₂ , MnO ₂ , CoO, Cr ₂ O ₃ , V ₂ O _{5 ,} Se , Au ₂ O ₃ , Ag ₂ O, CuO, CdO, SO ₃ , Cl, F, SnO ₂ , Sb ₂ O ₃ and the like, and may be a metal ion or an oxide. In the glass plate according to this embodiment, the NiO content is preferably 0.01% or less, and the total content of other components is more preferably 5% or less.
If the glass plate according to the present embodiment contains NiO, the glass may break due to the formation of NiS, so the content thereof is preferably 0.01% or less. The content of NiO in the glass plate according to the present embodiment is more preferably 0.005% or less, and even more preferably substantially no NiO is contained. Other ingredients may be present in an amount of up to 5% for various purposes (eg clarification and coloring). If the content of other components exceeds 5%, there is a risk that millimeter wave radio wave transmittance may be reduced. The content of other components is more preferably 2% or less, further preferably 1% or less, particularly preferably 0.5% or less, even more preferably 0.3% or less, and most preferably 0.1% or less. be. Moreover, in order to prevent the influence on the environment, the contents of As ₂ O ₃ and PbO are each more preferably less than 0.001%.

CeO ₂ acts as an oxidizing agent, can control the amount of FeO, and can also block ultraviolet rays. When the glass plate in this embodiment contains CeO ₂ , its content is preferably 0.004% or more, more preferably 0.01% or more, even more preferably 0.05% or more, and particularly preferably 0.1%. That's all. On the other hand, in order to increase productivity, the content of CeO ₂ in the glass plate in this embodiment is preferably 1% or less, more preferably 0.5% or less, and still more preferably 0.3% or less.
Cr ₂ O ₃ acts as an oxidizing agent and can control the amount of FeO. When the glass plate in this embodiment contains Cr ₂ O ₃ , the content is preferably 0.002% or more, more preferably 0.004% or more. Since Cr ₂ O ₃ has color in the visible range, there is a risk of a decrease in visible light transmittance. When the glass plate in this embodiment contains Cr ₂ O ₃ , the content is preferably 1% or less, more preferably 0.5% or less, particularly preferably 0.3% or less, and most preferably 0.1% or less.
SnO ₂ acts as a reducing agent and can control the amount of FeO. When the glass plate in this embodiment contains _SnO2 , its content is preferably 0.01% or more, more preferably 0.04% or more, still more preferably 0.06% or more, and particularly preferably 0.08%. That's all. On the other hand, in order to suppress defects derived from SnO ₂ during glass plate manufacture, the content of SnO ₂ in the glass plate in this embodiment is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0. .3% or less, most preferably 0.2% or less.
Moreover, P ₂ O ₅ tends to cause defects in the glass in the float bath when the glass plate in this embodiment is manufactured by the float method. Therefore, the content of P ₂ O ₅ in the glass plate in this embodiment is more preferably 1% or less, further preferably 0.1% or less, particularly preferably 0.05% or less, and most preferably less than 0.01%. It is.

(Materials other than glass materials)
In addition to glass, examples of materials constituting the radio wave transmitting member 12 include resin. Although the resin is not particularly limited, for example, ABS (acrylonitrile butadiene styrene), PVC (polyvinyl chloride), fluororesin, PC (polycarbonate), COP (cycloolefin polymer resin), SP S (Shindiotaku) (polystyrene resin), modified PPE (modified polyphenylene ether), urethane resin, polystyrene (PS), etc. can be used.

Note that in the configuration illustrated in FIG. 1, the window member 10 includes one radio wave transmitting member 12 that forms a trapezoidal area in plan view, but the shape and number of the radio wave transmitting member 12 are not limited to this configuration. For example, the radio wave transmitting member 12 may be circular or the like, and the radio wave transmitting member 12 may have a plurality of regions. That is, the window member 10 may include a plurality of first regions A. Although the shape of the radio wave transmitting member 12 is arbitrary, from the viewpoint of handling, the thickness of the radio wave transmitting member 12 is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 1.0 mm or more. Further, from the viewpoint of lightness, the thickness is preferably 2.3 mm or less, more preferably 2.0 mm or less. Furthermore, in the configuration illustrated in FIG. 1, the outer edge of the first area A in a plan view of the window member 10 partially overlaps with the outer edge of the first glass plate 11, but the outer edge of the first area A is , may be located inside the outer edge of the first glass plate 11. In that case, a window member 10 may be exemplified in which the first region A is provided with a resin and the second region B is provided with a second glass plate 13 that completely surrounds the resin (first region A). In this case, the cross-sectional view of the window member taken along line XX (in FIG. 1) shown in FIG. This is the configuration in which B is placed.

The radio wave transmitting member 12 and the second glass plate 13 are joined to the first glass plate 11 by a transparent resin layer 14.
As the transparent resin layer 14, materials that are generally employed in laminated glass conventionally used as window glasses for automobiles can be used, and for example, polyvinyl butyral, ethylene vinyl acetate, cycloolefin polymer, etc. can be used. The transparent resin layer 14 may use these alone or in combination. That is, as the transparent resin layer 14, a layer of resin containing at least one selected from the group consisting of polyvinyl butyral, ethylene vinyl acetate, and cycloolefin polymer can be used. Further, the transparent resin layer may use a liquid resin before heating.
Then, by laminating the first glass plate 11, the transparent resin layer 14, the second glass plate 13, and the radio wave transmitting member 12, and going through a process of heating and pressurizing, the first glass plate 11 and the second glass plate 11 are stacked. A window member 10 having a structure in which a glass plate 13 and a radio wave transmitting member 12 are joined via a transparent resin layer 14 is obtained.
Note that in the configuration shown in FIG. 1, the window member 10 includes only one transparent resin layer 14, but the window member 10 of this embodiment includes a plurality of transparent resin layers made of two or more of the above-mentioned resins. Good too.

Note that if the difference in linear expansion coefficient between the first glass plate 11 and the radio wave transmitting member 12 is large, cracks or warping may occur in the window member 10 due to the above-mentioned heating process, which may cause poor appearance. Therefore, it is preferable that the difference between the linear expansion coefficient of the first glass plate and the linear expansion coefficient of the radio wave transmitting member be as small as possible. The difference in linear expansion coefficients between the first glass plate and the radio wave transmitting member may be expressed as a difference in average linear expansion coefficients in a predetermined temperature range. In addition, when the radio wave transmitting member is made of a resin material, the glass transition point of the resin material is lower than that of the glass material. may be set. Note that the difference in linear expansion coefficient between the first glass plate and the resin material may be set by a predetermined temperature below the glass transition point of the resin material.

Further, the transparent resin layer 14 may be an adhesive layer made of an adhesive, and the adhesive is not particularly limited, but for example, an acrylic adhesive, a silicone adhesive, or the like can be used.
When the transparent resin layer 14 is an adhesive layer, there is no need for a heating process in the process of bonding the first glass plate 11, the second glass plate 13, and the radio wave transmitting member 12, so that the above-mentioned cracks and There is no risk of warping. The thickness of the transparent resin layer 14 may be approximately 0.1 mm to 1 mm. Further, from the viewpoint of handling, the thickness of the second glass plate 13 is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 1.0 mm or more. Further, from the viewpoint of lightness, the thickness is preferably 2.3 mm or less, more preferably 2.0 mm or less.

In the window member 10 of this embodiment, layers other than the first glass plate 11, the radio wave transmitting member 12, the second glass plate 13, and the transparent resin layer 14 (hereinafter also referred to as "other layers") have the effects of the present invention. It may be provided as long as it does not impair it. For example, it may be provided with a coating layer that provides a water repellent function, a hydrophilic function, an antifogging function, etc., an infrared reflective film, and the like. The positions where the other layers are provided are not particularly limited, and they may be provided on the surface of the window member 10 or may be provided so as to be sandwiched between the plurality of transparent resin layers 14. Further, the window member 10 of the present embodiment may include a black ceramic layer or the like disposed in a band shape on a part or all of the peripheral edge for the purpose of hiding the attachment portion to the frame etc. and the wiring conductor. good.

Hereinafter, with reference to the drawings, a case will be described in which the window member 10 of this embodiment is used as a window glass for an automobile.
FIG. 3 is a conceptual diagram showing a state in which the window member 10 of this embodiment is attached to an opening 110 formed in the front of the automobile 100 and used as a window glass of the automobile. A housing (case) 120 housing an information device is attached to a surface of a window member 10 used as a window glass of a vehicle on the inside side of the vehicle to ensure safe running of the vehicle. An information device is a device that uses a camera, radar, etc. to prevent rear-end collisions with vehicles, pedestrians, obstacles, etc. in front of the vehicle, and to notify the driver of danger, such as an information receiving device and/or Information transmitting devices, etc., including millimeter wave radar, stereo cameras, infrared lasers, etc., that transmit and receive signals. The "signal" refers to electromagnetic waves including millimeter waves, visible light, infrared light, etc.

FIG. 4 is an enlarged view of the S portion in FIG. 3, and is a perspective view showing a portion where the housing 120 is attached to the window member 10 of this embodiment. A millimeter wave radar 201 and a stereo camera 202 are housed in the housing 120 as information devices. As shown in FIG. 4, the window member 10 of this embodiment is arranged such that the first region A, which is a region with excellent radio wave transparency, is located around information devices such as the millimeter wave radar 201 and the stereo camera 202. used. The housing 120 housing the information device is usually attached to the outside of the vehicle than the rearview mirror 150 and to the inside of the vehicle than the window member 10, but may be attached to other parts.

FIG. 5 is a cross-sectional view in a direction including line YY in FIG. 4 and perpendicular to the horizontal line. Although the first glass plate 11 of the window member 10 is normally arranged on the outside of the vehicle, the first glass plate 11 may be arranged on the inside of the vehicle. Note that, as described above, the incident angle θ of the radio waves 300 used for communication of information devices such as the millimeter wave radar 201 with respect to the main surface of the first glass plate 11 can be evaluated as 67.5°.

[Second embodiment]
6A and 6B are cross-sectional views of an example of the window member 20 of the second embodiment. The window member 20 shown in FIG. 6A is a diagram illustrating a case where the first region A includes one layer of the radio wave transmitting member 22 in contact with the first glass plate 21. In addition, in the window member 20 shown in FIG. 6B, as the first region A, the radio wave transmitting member 22 in contact with the first glass plate 21 is formed from two layers of the first radio wave transmitting member 22a and the second radio wave transmitting member 22b. It is a figure which illustrated the case where it becomes. This embodiment differs from the first embodiment in that the radio wave transmitting member 22 is adjacent to the first glass plate 21. Note that in this embodiment, the second glass plate 23 is bonded to the first glass plate 21 by a transparent resin layer 24, as in the first embodiment. The first glass plate 21, second glass plate 23, transparent resin layer 24, and other layers in this embodiment are the same as those described in the first embodiment.
In this embodiment, the radio wave transmitting member 22 is made of a material that can be directly bonded to the first glass plate 21 through a heating and pressurizing process, and is directly bonded to the first glass plate 21 .
In addition, in the window member 20 of this embodiment, as in the first embodiment, the outer edge of the first area A is located inside the outer edge of the first glass plate 11 in a plan view of the window member 20. You can. That is, in this case, the cross-sectional view of the window member taken along the line XX (in FIG. 1) shown in FIGS. It is also possible to have a configuration in which

Further, in the window member 20 of this embodiment, a material that can be directly bonded to the first glass plate 21 through a heating and pressurizing process includes, for example, urethane resin. The layer made of urethane resin (urethane resin layer) may be composed of a single layer, but in order to improve the strength, it is preferable to laminate a plurality of layers and use it as the radio wave transmitting member 22. In this way, when using urethane resin as the radio wave transmitting member 22, the number of urethane resin layers may be in the range of 1 to 5 from the viewpoint of strength and radio wave transmittance. Since the adhesion and strength between the first glass plate 21 and the urethane resin layer are improved, the number of layers is preferably 2 to 5 layers, more preferably 2 to 4 layers, and particularly preferably 2 layers. Further, the total thickness of the urethane resin layer should be thicker than the transparent resin layer 24 and in contact with the end surface of the second glass plate 23, and from the viewpoint of strength, it is preferably 1.0 mm or more, and 1.2 mm or more. More preferred. Further, the total thickness of the urethane resin layer is preferably 2 mm or less, more preferably 1.8 mm or less, from the viewpoint of millimeter wave radio wave transparency. Note that the window member 20 shown in FIG. 6A is a schematic cross-sectional view when one or more (2 to 5 layers) of one type of (resin) material, such as a urethane resin layer, are laminated as the radio wave transmitting member 22. .

In addition, from the viewpoint of strength in addition to high millimeter wave transmittance, the urethane resin layer to be used preferably has a tear strength of 40 KN/m or more according to the test method of ASTM standard D624, Die C, and 50 KN/m or more. is more preferable. Furthermore, from the viewpoint of strength in addition to high millimeter wave transmittance, the urethane resin layer used preferably has a tensile strength of 30 MPa or more, more preferably 40 MPa or more, according to the ASTM standard D412 test method.

Furthermore, the window member 20 of this embodiment may be used as the radio wave transmitting member 22 by laminating two or more layers, including a layer made of a material that can be directly bonded to the first glass plate 21 by heating and pressurizing. good. The radio wave transmitting member 22 in the window member 20 shown in FIG. 6B is a schematic cross-sectional view when the first radio wave transmitting member 22a and the second radio wave transmitting member 22b are laminated in this order from the first glass plate 21 side. be. The first radio wave transmitting member 22a may be, for example, one or multiple (2 to 5) urethane resin layers. The second radio wave transmitting member 22b only needs to have high radio wave transmittance to millimeter wave radio waves, and examples of its material include polycarbonate resin, acrylic resin, cycloolefin polymer (COP), Fluororesin, PET resin, glass of composition A, glass of composition B, glass of composition C, etc. can be used. Note that as the material for the second radio wave transmitting member 22b, polycarbonate resin is particularly preferable from the viewpoint of heat resistance during manufacturing, and for the combination of the first radio wave transmitting member 22a and the second radio wave transmitting member 22b, urethane resin is preferable. More preferred is a combination of a resin layer and a polycarbonate resin layer. Further, when the material of the second radio wave transmitting member 22b is polycarbonate resin, the thickness of the second radio wave transmitting member 22b made of polycarbonate resin is preferably 0.5 mm or more from the viewpoint of workability, and more preferably 1 mm or more. preferable. Further, the thickness of the second radio wave transmitting member 22b made of polycarbonate resin is preferably 5 mm or less, more preferably 2 mm or less, from the viewpoint of millimeter wave radio wave transmittance.
In manufacturing the window member 20 of this embodiment, a single heating and pressurizing process is performed to bond the radio wave transmitting member 22 to the first glass plate 21 and bond the second glass plate through the transparent resin layer 24. The glass plate 23 can be bonded to the first glass plate 21 at the same time.

[Third embodiment]
FIG. 7 is a sectional view of the window member 30 of the third embodiment. The window member 30 of this embodiment includes a radio wave transmitting member 32 in the entire area facing the main surface of the first glass plate 31. In this embodiment, the radio wave transmitting member 32 is joined to the first glass plate 31 via the transparent resin layer 34. That is, the window member 30 of this embodiment is a laminate in which the first glass plate 31, the transparent resin layer 34, and the radio wave transmitting member 32 are laminated in this order over the entire area. The first glass plate 31, transparent resin layer 34, and other layers in this embodiment are the same as those described in the first embodiment.

In this embodiment, in order to ensure the strength of the window member 30, the radio wave transmitting member 32 is preferably made of glass, and in particular, it is preferably made of glass having the aforementioned composition A, composition B, or composition C. is preferred.
The window member 30 of this embodiment has fewer parts than a window member in which a part of the region (first region A) facing the main surface of the first glass plate 31 includes a radio wave transmitting member. In addition, the number of man-hours required for parts processing can be reduced, resulting in excellent productivity. Moreover, the window member 30 of this embodiment is a combination in which the first glass plate 31 is made of glass conventionally used for laminated glass of automobiles, and the radio wave transmitting member 32 is made of glass having composition A, composition B, or composition C. But that's fine. Furthermore, in this embodiment, higher radio wave transmittance can be achieved by using glass having composition A, composition B, or composition C for both the radio wave transmitting member 32 and the first glass plate 31. In this case, the combination of glasses (glasses having compositions A to C) in the radio wave transmitting member 32 and the first glass plate 31 may be arbitrary.
Further, since the window member 30 of this embodiment has excellent radio wave transparency as a whole, it is also excellent in that the mounting position of a radio wave transmitting/receiving device (millimeter wave radar etc.) is not limited.

[Fourth embodiment]
FIG. 8 is a sectional view of the window member 40 of the fourth embodiment. Specifically, the window member 40 shown in FIG. 8 is an embodiment in which the radio wave transparent member 12 of the window member 10 of the first embodiment is replaced with the radio wave transparent member 22 of the window member 20 shown in FIG. 6B. be. That is, in the window member 40 of the fourth embodiment shown in FIG. 8, the radio wave transmitting member 42 in contact with the transparent resin layer 44 is composed of two layers: a first radio wave transmitting member 42a and a second radio wave transmitting member 42b. FIG. This embodiment differs from the first embodiment in that region A has a transparent resin layer 44 and the radio wave transmitting member 42 has two layers. Note that in this embodiment, the second glass plate 43 is bonded to the first glass plate 41 by a transparent resin layer 44, as in the first embodiment. The first glass plate 41, second glass plate 43, and transparent resin layer 44 in this embodiment are the same as those described in the first embodiment.

Furthermore, among the window member 40 of the fourth embodiment shown in FIG. The first radio wave transmitting member 22a and the second radio wave transmitting member 22b described in can be applied. That is, in the window member 40 of the fourth embodiment, in the area A, the first glass plate 41, the transparent resin layer 44, the first radio wave transmitting member 42a, and the second radio wave transmitting member 42b are laminated in this order. Has a structure.

Furthermore, in the window member 40 of this embodiment, the first radio wave transmitting member 42a is preferably thinner. When using a urethane resin layer as the first radio wave transmitting member 42a, the total thickness of the urethane resin layer may be 0.5 mm or more and preferably 0.6 mm or more. Further, the total thickness of the urethane resin layer is preferably 2.0 mm or less, more preferably 1.0 mm or less, from the viewpoint of millimeter wave radio wave transparency. Furthermore, in the window member 40 of this embodiment, when polycarbonate resin is used as the second radio wave transmitting member 42b, the thickness range may be within the range shown in the second embodiment.

The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto.

[Manufacture of glass plates]
<Manufacture of glass plates of composition examples 1 to 6>
First, raw materials were put into a platinum crucible so as to have the glass composition (unit: mol %) shown in Table 1, and melted at 1550°C for 2 hours, then the molten liquid was poured out onto a carbon plate and slowly cooled. Six types of glass plates of Composition Examples 1 to 6 were obtained. Both sides of the obtained plate were polished to obtain a glass plate of predetermined dimensions. Table 1 shows the specific gravity, average coefficient of thermal expansion from 50° C. to 350° C., T ₂ , T ₄ , T _L , glass transition point T _g , and β-OH of the obtained glass plate. Note that "-" in the table indicates that no measurements were taken, and values calculated from the composition are shown in parentheses. Note that the glass of Composition Example 1 is a glass that is conventionally used in laminated glass used as window members for automobiles. The glasses of composition examples 2 to 6 correspond to composition A described above.
<Manufacture of glass plate of composition example 7>
In addition, raw materials were put into a platinum crucible and melted at 1650°C for 2 hours so that the glass composition (unit: mol %) shown in Composition Example 7 in Table 1 was obtained, and then the molten liquid was poured out onto a carbon plate. It was slowly cooled to obtain a glass plate of Composition Example 7. Both sides of the obtained plate were polished to obtain a glass plate of predetermined dimensions. Note that the glass of Composition Example 7 is an alkali-free glass.
<Manufacture of glass plates of composition examples 8 to 10>
In addition, raw materials were put into a platinum crucible and melted at 1650°C for 2 hours so that the glass compositions (unit: mol%) shown in composition examples 8 to 10 in Table 3 were obtained, and then the molten liquid was poured onto a carbon plate. The mixture was taken out and slowly cooled to obtain glass plates having composition examples 8 to 10. Both sides of the obtained plate were polished to obtain a glass plate of predetermined dimensions. The glasses of composition examples 8 and 9 are alkali-free glasses that correspond to composition C, and the glasses of composition example 10 correspond to composition A.

[Manufacture of window components]
<Example 1>
As the first glass plate, the glass plate of Composition Example 1 (300 mm x 300 mm, thickness 2 mm) was used as the transparent resin layer, and as the transparent resin layer, a polyvinyl butyral (PVB) film (manufactured by Sekisui Chemical Co., Ltd., 300 mm x 300 mm, thickness 0) was used. A glass plate of Composition Example 7 (300 mm x 300 mm, thickness 2 mm) was used as a radio wave transmitting member. The first glass plate, the transparent resin layer, and the radio wave transmitting member were laminated in this order, evacuated using a vacuum packaging machine, and then heated (120° C., 30 minutes) to temporarily press-bond them. Furthermore, the window member of Example 1 was obtained by performing a pressure bonding process (1 MPa, 130° C., 3 hours) using an autoclave.

<Example 2>
Except that a resin plate made of cycloolefin polymer (COP) (manufactured by Nippon Zeon Co., Ltd., 300 mm x 300 mm, thickness 2 mm, linear expansion coefficient at 100 °C 70 × 10 ^-6 °C ^-1 ) was used as the radio wave transmitting member. A window member of Example 2 was obtained in the same manner as Example 1.

<Example 3>
Example 1 except that a polycarbonate (PC) resin plate (manufactured by Takiron C.I. Co., Ltd., 300 mm x 300 mm, thickness 2 mm, linear expansion coefficient at 100 °C 56 x 10 ^-6 °C ^-1 ) was used as the radio wave transmitting member. In the same manner as above, a window member of Example 3 was obtained.

<Comparative example 1>
A window member of Comparative Example 1 was obtained in the same manner as in Example 1 except that the glass plate of Composition Example 1 was used in place of the radio wave transmitting member in the same manner as the first glass plate in Example 1.
The structure of Comparative Example 1 in which two glass plates of Composition Example 1 are bonded via PVB is similar to that of laminated glass conventionally used as window glass for automobiles.

<Example 4>
As in Example 1, the glass plate of Composition Example 1 was used as the first glass plate, and the glass plate of Composition Example 7 was used as the radio wave transmitting member. A transparent adhesive (manufactured by Taica Co., Ltd.) is applied to one main surface of the first glass plate to a thickness of 0.5 mm to form a transparent resin layer (adhesive layer), and then The window member of Example 4 was obtained by joining the radio wave transmitting member by roll lamination.

<Example 5>
A window member of Example 5 was obtained in the same manner as in Example 4 except that the same resin plate made of cycloolefin polymer (COP) as in Example 2 was used as the radio wave transmitting member.

<Example 6>
A window member of Example 6 was obtained in the same manner as in Example 4 except that the same polycarbonate (PC) resin plate as in Example 3 was used as the radio wave transmitting member.

<Example 7>
The glass plate of Composition Example 1 was used as the first glass plate, and a two-layer urethane resin plate (Higress SHG7180 manufactured by Seedam Co., Ltd., 300 mm x 300 mm, thickness 1.27 mm, at 100°C) was used as the radio wave transmitting member. A linear expansion coefficient of 10×10 ⁻⁵ °C ⁻¹ ) was used.
A two-layer urethane resin plate is placed on the surface of the first glass plate, and is temporarily crimped using a vacuum packaging machine under the same conditions as in Example 1, and then crimped using an autoclave. By performing this, a window member of Example 7 was obtained.

<Example 8>
Except that a resin plate made of cycloolefin polymer (COP) (manufactured by Nippon Zeon Co., Ltd., 300 mm x 300 mm, thickness 2 mm) with a smaller coefficient of linear expansion than that used in Example 2 was used as the radio wave transmitting member. A window member of Example 8 was obtained in the same manner as in Example 1.

<Examples 9 to 13>
In the same manner as in Example 1, except that the glass plates of Composition Examples 2, 3, 4, 5, and 6 (all 300 mm x 300 mm, 2 mm thick) were used as the first glass plate and the radio wave transmitting member, Window members of Examples 9, 10, 11, 12 and 13 were obtained.

<Example 14>
Except that a polystyrene (PS) resin plate (manufactured by Idemitsu Kosan Co., Ltd., 300 mm x 300 mm, thickness 2 mm, linear expansion coefficient at 100 °C 20 × 10 ^-6 °C ^-1 ) was used as the radio wave transmitting member. A window member of Example 14 was obtained in the same manner as Example 1.

<Examples 15 to 18>
Examples 15 to 18 were prepared in the same manner as in Example 1 except that the glass plates of Composition Examples 8 to 11 (all 300 mm x 300 mm, 2 mm thick) were used as the first glass plate and the radio wave transmitting member. A window member was obtained.

<Examples 19-21>
As the first glass plate, glass plates of composition examples 8 to 10 (all 300 mm x 300 mm, thickness 3.2 mm) were used, and as radio wave transmitting members, glass plates of compositions 8 to 10 (all 300 mm x 300 mm, thickness 0 Window members of Examples 19 to 21 were obtained in the same manner as in Example 1 except that .8 mm) was used.

<Example 22>
As the radio wave transmitting member, the two-layer urethane resin plate used in Example 7 and the same thickness of polycarbonate (PC) as in Example 3 (laminated on the side opposite to the first glass plate) were used. A 1 mm resin plate was used.
A two-layer urethane resin plate and a polycarbonate resin plate are placed in this order on the surface of the first glass plate, and temporarily crimped using a vacuum packaging machine under the same conditions as in Example 1. A window member of Example 22 was obtained by performing a pressure bonding process using an autoclave.

<Example 23>
As a radio wave transmitting member, the two-layer urethane resin plate used in Example 7 was made to have a thickness of 0.635 mm, and the same polycarbonate as in Example 3 was used (laminated on the side opposite to the first glass plate). A resin plate made of (PC) and having a thickness of 1 mm was used.
On the surface of the first glass plate, a transparent resin layer (PVB film) similar to that in Example 1, a two-layer urethane resin plate, and a polycarbonate resin plate were arranged in this order, and the same conditions as in Example 1 were applied. Then, a window member of Example 23 was obtained by performing temporary pressure bonding using a vacuum packaging machine and further performing a pressure bonding process using an autoclave.

[Measurement of radio wave transmittance T(F)]
For the window members of Examples 1 to 23 and Comparative Example 1, the transmittance T (F) of radio waves of frequency F (GHz) incident at an incident angle of 67.5° was determined in the range of 60 GHz≦F (GHz)≦100 GHz. Calculated by simulation. In the simulation, for Examples 1 to 23 and Comparative Example 1, the insertion loss (S21 parameter) derived based on the dielectric constant and dielectric loss tangent of each material used was converted into (millimeter wave) transmittance. In addition, regarding the window members of Examples 1, 4, and 6 and Comparative Example 1, the radio wave transmittance of the produced window members was measured using a free space method.

Radio wave transparency was determined by placing the antennas facing each other and installing each obtained window member between them so that the angle of incidence was 67.5°. The radio wave transmittance was calculated from the results of measuring the radio wave transmission loss when the case where there was no transparent substrate was set to 0 dB. As a result, the radio wave transmittance at 79 GHz of the window members of Examples 1, 4, and 6 and Comparative Example 1 was equivalent to that of the simulation.

The simulation results for Comparative Example 1 are shown in FIG. 9, and the simulation results for Examples 4 to 7, 9, and 14 are shown in FIG. The dotted lines in FIGS. 9 and 10 indicate the following formulas (1) to (4). At this time, the window member may satisfy the following formula (1), preferably the following formula (2), more preferably the following formula (3), and even more preferably the following formula (4).
T(F)>-0.0061×F+0.9384...(1)
T(F)>-0.0061×F+0.9784...(2)
T(F)>-0.0061×F+1.0384...(3)
T(F)>-0.0061×F+1.0554...(4)

Although simulation results for Examples 1 to 3, 8, and 10 to 13 are not shown, Example 1 is similar to Example 4, Examples 2 and 8 are similar to Example 5, and Example 3 is similar to Example 6. Similarly, Examples 10 to 13 show high transmittances similar to or higher than Example 9, and all Examples satisfy the above formula (1) in the range of 60 GHz≦F (GHz)≦100 GHz. Furthermore, the above formula (2) was also satisfied.

FIG. 11 shows simulation results for Examples 15, 17, 18, 19, 21, 22, and 23 in the same manner as FIG. 10. Although Examples 16 and 20 are not shown, Example 16 is almost the same as Example 15, and Example 20 is almost the same as Example 19, and both satisfy the above formula ( 1) was satisfied, and the above formulas (2) to (4) were also satisfied. Moreover, Examples 22 and 23 satisfied the above formula (1) and the above formula (2) within the range of 60 GHz≦F(GHz)≦100 GHz. Note that the unit of transmittance on the vertical axis in Figures 9 to 11 is "%", so the transmittance value in these figures is the value obtained by multiplying the left side of equations (1) to (4) by 100. corresponds to

[Evaluation of window components]
<Radio wave transparency>
Using the above radio wave transmittance measurement results, those with a radio wave transmission loss greater than 3 dB at a frequency of 79 GHz were evaluated as poor (x), and those with a radio wave transmission loss of 3 dB or less were evaluated as good (◯). The evaluation results are shown in Tables 2 and 3.

<Exterior>
The presence or absence of warping or cracking was visually determined for the window members of each example, and those with no warping or cracking were rated ○, and those with signs of warping or cracking were rated △. The results are shown in Tables 2 and 3.

Comparative example 1 where the transmittance T (F) of radio waves with frequency F (GHz) incident at an incident angle of 67.5° has a frequency that does not satisfy formula (1) in the range of 60 GHz ≦ F (GHz) ≦ 100 GHz. The window members had poor radio wave transparency.
On the other hand, an example in which the transmittance T (F) of a radio wave with a frequency F (GHz) incident at 67.5° satisfies equations (1) and (2) in the range of 60 GHz≦F (GHz)≦100 GHz. Window members Nos. 1 to 23 had excellent radio wave transmittance.
Further, Examples 1 to 8 and implementations in which the transmittance T (F) of a radio wave with a frequency F (GHz) incident at 67.5° satisfies equation (3) in the range of 60 GHz≦F (GHz)≦100 GHz The window members of Examples 14 to 21 had excellent radio wave transparency. Furthermore, in Examples 1 to 5, Example 8, and Examples 14 to 21, the transmittance T (F) of a radio wave with a frequency F (GHz) incident at an incident angle of 67.5° is 60 GHz≦F (GHz). )≦100GHz, formula (4) was also satisfied.
Although the window members of Examples 1 to 3 had excellent radio wave transmittance, signs of warping and cracking were observed. This is considered to be due to the fact that in these examples, a manufacturing method involving heating was adopted, even though the difference in linear expansion coefficient between the first glass plate and the radio wave transmitting member was relatively large.

Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on the Japanese patent application filed on October 31, 2018 (Japanese patent application No. 2018-205674) and the Japanese patent application filed on October 3, 2019 (Japanese patent application No. 2019-183289), the contents of which can be found here. is included as a reference.

10, 20, 30, 40 Window member 11, 21, 31, 41 First glass plate 12, 22, 32, 42 Radio wave transmission member 22a, 42a First radio wave transmission member 22b, 42b Second radio wave transmission member 13 , 23, 43 second glass plate 14, 24, 34, 44 transparent resin layer 100 automobile 110 opening 120 housing 150 rearview mirror 201 millimeter wave radar 202 stereo camera 300 radio wave A first area B second area

Claims (20)

a first glass plate having a thickness of 1.1 mm or more;
a radio wave transmitting member facing the main surface of the first glass plate;
Equipped with
The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The following formula (1) is satisfied within the range of 60GHz≦F≦100GHz ,
A first region including the radio wave transmitting member in plan view, and a second region not including the radio wave transmitting member in plan view, and in the second region, the main surface of the first glass plate and A window member comprising a second opposing glass plate .
T(F)>-0.0061×F+0.9384...(1) a first glass plate having a thickness of 1.1 mm or more;
a radio wave transmitting member facing the main surface of the first glass plate;
Equipped with
The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The following formula (1) is satisfied within the range of 60GHz≦F≦100GHz,
The radio wave transmitting member is a window member including at least one urethane resin layer.
T(F)>-0.0061×F+0.9384...(1) The window member according to claim 2, wherein the radio wave transmitting member further includes a polycarbonate resin layer laminated on a surface of the urethane resin layer opposite to the first glass plate. The window member according to claim 2 or 3, wherein the urethane resin layer is adjacent to the first glass plate. a first glass plate having a thickness of 1.1 mm or more;
a radio wave transmitting member facing the main surface of the first glass plate;
Equipped with
The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The following formula (1) is satisfied within the range of 60GHz≦F≦100GHz,
A window member comprising a transparent resin layer between the first glass plate and the radio wave transmitting member, the radio wave transmitting member being made of alkali-free glass or resin.
T(F)>-0.0061×F+0.9384...(1) a first glass plate having a thickness of 1.1 mm or more;
a radio wave transmitting member facing the main surface of the first glass plate;
Equipped with
The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The following formula (1) is satisfied within the range of 60GHz≦F≦100GHz,
Both the first glass plate and the radio wave transmitting member have a content expressed as a molar percentage based on oxides of each component, where RO is the sum of the contents of MgO, CaO, SrO and BaO, and R ₂ When O is the total amount of alkali metal oxides,
72≦SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ≦98
55≦SiO ₂ ≦87
0≦Al ₂ O ₃ ≦20
5≦B ₂ O ₃ ≦25
0≦R ₂ O≦5
0≦RO≦20
0≦Al ₂ O ₃ /B ₂ O ₃ ≦0.35
A window member made of glass having a composition C that satisfies the following.
T(F)>-0.0061×F+0.9384...(1) The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The window member according to any one of claims 1 to 6, which satisfies the following formula (2) within the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+0.9784...(2) The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The window member according to claim 7 , which satisfies the following formula (3) within the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0384...(3) The transmittance T (F) of a radio wave having a frequency F (GHz) that is incident on the region provided with the radio wave transmitting member at an incident angle of 67.5° with respect to the main surface of the first glass plate in a plan view is: The window member according to claim 8 , which satisfies the following formula (4) in the range of 60 GHz≦F≦100 GHz.
T(F)>-0.0061×F+1.0554...(4) 7. The window member according to claim 6 , wherein the radio wave transmitting member is provided in the entire area facing the main surface of the first glass plate, and the radio wave transmitting member is made of glass. The window member according to claim 1, further comprising a transparent resin layer between the first glass plate and the radio wave transmitting member. The window member according to claim 11 , wherein the transparent resin layer contains at least one selected from the group consisting of polyvinyl butyral, ethylene vinyl acetate, and cycloolefin polymer. The window member according to claim 11 , wherein the transparent resin layer is an adhesive layer. 6. The window member according to claim 1 , further comprising a transparent resin layer between the first glass plate and the radio wave transmitting member, wherein the radio wave transmitting member is made of a cycloolefin polymer. At least one of the first glass plate and the radio wave transmitting member has a content expressed as a molar percentage based on oxides of each component; RO is the sum of the contents of MgO, CaO, SrO, and BaO _; is the total amount of alkali metal oxides,
50≦ _SiO2 ≦85
0≦ _{Al2O3 ≦} 20
4≦ _R2O ≦22
0≦RO≦20
0≦ _Na2O / _R2O ≦0.8
0≦ _K2O / _R2O ≦0.7
The window member according to any one of claims 1 to 5 , which is made of glass having a composition A that satisfies the following. Both the first glass plate and the radio wave transmitting member have a content expressed as a molar percentage based on oxides of each component, RO is the sum of the contents of MgO, CaO, SrO and BaO, and R 2 O is the sum of the contents of MgO, CaO, SrO and _BaO . , when taken as the total amount of alkali metal oxides,
50≦SiO2 _≦ 85
0 ≦ _{Al2O3 ≦} 20
4≦R2O _≦ 22
0≦RO≦20
0≦Na2O _/ R2O _≦ 0.8
0≦K2O _/ R2O _≦ 0.7
The window member according to claim 1 or 5, which is made of glass having a composition A that satisfies the following . At least one of the first glass plate and the radio wave transmitting member has a total content of SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ of 72% or more, expressed as a molar percentage based on oxides of each component. The window member according to any one of claims 1 to 5 , which is made of a certain glass. At least one of the first glass plate and the radio wave transmitting member has a content expressed as a mole percentage based on oxides of each component, such that RO is the total content of MgO, CaO, SrO, and BaO, and _R is the total amount of alkali metal oxides,
72≦SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ≦98
55≦ _SiO2 ≦87
0≦ _{Al2O3 ≦} 20
5≦ _{B2O3 ≦} 25
0≦R ₂ O≦5
0≦RO≦20
0≦ _{Al2O3 / B2O3 ≦} 0.35
The window member according to claim 17, which is made of glass having a composition C that satisfies the following. Both the first glass plate and the radio wave transmitting member have a content expressed as a molar percentage based on oxide of each component, RO is the sum of the contents of MgO, CaO, SrO, and BaO, and R 2 _O is , when taken as the total amount of alkali metal oxides,
72≦SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ≦98
55≦SiO2 _≦ 87
0 ≦ _{Al2O3 ≦} 20
5 ≦ _{B2O3 ≦} 25
0≦R ₂ O≦5
0≦RO≦20
0 _{≦ Al2O3} / _B2O3 ≦ 0.35 _ _{_}
The window member according to claim 1 or 5, which is made of glass having a composition C that satisfies the following . The window member according to any one of claims 1 to 19, wherein the total thickness is 3.5 mm or more and 10 mm or less, and the thickness of the radio wave transmitting member is 0.4 mm or more and 2.5 mm or less.

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