Glass for vehicles and sensors, bent glass, and laminated glass

Abstract

The present invention pertains to a glass for vehicles and sensors, which substantially does not contain Li2O and contains components which are SiO2, B2O3, Al2O3, MgO, CaO, SrO, BaO, Na2O, K2O, R'2O, and RO (wherein RO represents the total content of MgO, CaO, SrO, and BaO, and R'2O represents the total content of Na2O and K2O), in specified ranges as expressed in mol% based on oxides. The present invention also pertains to a glass for vehicles and sensors, which contains components which are SiO2, B2O3, Al2O3, MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, R2O, and RO (wherein RO represents the total content of MgO, CaO, SrO, and BaO, and R2O represents the total content of Li2O, Na2O, and K2O), in specified ranges as expressed in mol% based on oxides.

Description

Vehicle and sensor glass, curved glass, laminated glass

[0001] This invention relates to glass for vehicles and sensors, curved glass, and laminated glass.

[0002] In recent years, glass used in mobility applications, such as vehicle glass and cover glass for sensors like LiDAR (Light Detection and Ranging), has been required to be stronger in order to extend its lifecycle from a carbon neutrality perspective.

[0003] To improve the strength of glass, for example, increasing the Young's modulus or fracture toughness of the glass is effective (see, for example, Patent Documents 1 and 2).

[0004] International Publication No. 2012 / 086664, Japanese Patent Publication No. 2019-529298

[0005] However, glass with a high Young's modulus and fracture toughness tends to be highly viscous. Therefore, such glass is not suitable for applications requiring bending, such as vehicle windows or cover glass for sensors like LiDAR.

[0006] For example, the glass described in Patent Document 1 has a Young's modulus of 81 GPa or higher and a fracture toughness value of 0.9 MPa·m １／２ Although the values ​​are high, the glass transition temperature is high at over 600°C. Furthermore, the glass described in Patent Document 2 has a Young's modulus of 85 GPa or higher and a fracture toughness value of 0.86 MPa·m. １／２ Although the temperature is high, the annealing point is also high at over 800°C.

[0007] Furthermore, glass with a high Young's modulus generally tends to have a high density, meaning it tends to be heavy. Therefore, using such glass in mobility applications such as vehicles and sensors is undesirable from the standpoint of fuel efficiency and energy consumption. Thus, it has been difficult to achieve glass with excellent fracture toughness, low viscosity, and low density using conventional technology.

[0008] In view of the above problems, an object of the present invention is to provide glass for vehicles and sensors, bent glass, and laminated glass that have excellent fracture toughness, low viscosity, and low density.

[0009] The inventors of the present invention have found that the above problems can be solved by using glass having a specific composition range, and have completed the present invention.

[0010] That is, the present invention is as follows. [1] In terms of mol% based on oxides, Li ２ O is not substantially contained, and SiO ２ : 70.0 to 80.0% B ２ O ３ : 10.0 to 17.0% Al ２ O ３ : 1.0 to 6.0% MgO: 0.0 to 5.0% CaO: 0.0 to 5.0% SrO: 0.0 to 5.0% BaO: 0.0 to 5.0% Na ２ O: 0.0 to 19.0% K ２ O: 0.0 to 10.0% R' ２ O: 6.0 to 19.0% RO: 0.0 to 5.0% (where RO is the total content of MgO, CaO, SrO, and BaO, and R' ２ O is the total content of Na ２ O and K ２ O), and ([R' ２ O] + 1 / 2[RO] - [Al ２ O ３ ) - [B ２ O ３ ≧ -6.5 (where [], means the content in terms of mol% based on oxides of each component within the parentheses), glass for vehicles and sensors. [2] ([R' ２ O] + 1 / 2[RO] - [Al ２ O ３ ) - [B ２ O ３ > -3.0, the glass for vehicles and sensors according to [1]. [3] In terms of mol% based on oxides, SiO ２ : 70.0 to 80.0% B ２ O ３ : 10.0 to 17.0% Al ２O ３ :1.0~6.0% MgO:0.0~5.0% CaO:0.0~5.0% SrO:0.0~5.0% BaO:0.0~5.0% Li ２ O: more than 0.0 to 15.0% Na ２ O: 3.5-15.0% K ２ O: 0.0 to 10.0% R ２ O: 6.0–19.0% RO: 0.0–5.0% (However, RO is the total content of MgO, CaO, SrO and BaO, R ２ O is Li ２ O, Na ２ O and K ２ It contains (the total amount of O), ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Vehicle and sensor glass where ] ≥ -10.0 (where [ ] means the content of each component in parentheses in mol% on an oxide basis). [4] ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ [3] Vehicle and sensor glass as described in [3], wherein the content of three-coordinate boron is B ２ O ３ Vehicle and sensor glass according to any one of [1] to [4], which is 10.0 mol% or less when converted. [6] In mol% on an oxide basis, SiO ２ , B ２ O ３ and Al ２ O ３ Vehicle and sensor glass according to any one of [1] to [5], wherein the total content of is 81.0 to 93.0%. [7] The content of three-coordinate boron is B ２ O ３ The converted amount is greater than 0.0 mol% and less than or equal to 7.0 mol%, and the content of four-coordinate boron is B ２ O ３Vehicle and sensor glass according to any one of [1] to [6], wherein the Young's modulus is 9.5 to 15.0 mol%. [8] Vehicle and sensor glass according to any one of [1] to [7], wherein the Young's modulus is 70 GPa or higher. [9] Fracture toughness value K measured by the SEPB method. ＩＣ 0.85 MPa·m １／２ The above is a vehicle and sensor glass according to any one of [1] to [8].

[10] Glass viscosity is 10 １１ Temperature T at which dPa·s occurs １１ Vehicle and sensor glass according to any one of [1] to [9], wherein the temperature is 640°C or lower.

[11] Vehicle and sensor glass according to any one of [1] to

[10] , wherein the Young's modulus is 80 GPa or higher.

[12] Fracture toughness value K measured by the SEPB method. ＩＣ 0.94 MPa·m １／２The above is true for vehicle and sensor glass according to any one of [1] to

[11] .

[13] When a tungsten carbide cemented carbide alloy with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted, the critical impact fracture velocity is 40 km / h or more, according to any one of [1] to

[12] .

[14] The vehicle and sensor glass according to any one of [1] to

[13] , when a tungsten carbide cemented carbide alloy with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted, the critical impact fracture velocity is 60 km / h or more.

[15] The vehicle and sensor glass according to any one of [1] to

[14] , with a thickness of 2.5 mm or more.

[16] A bendable glass made of the vehicle and sensor glass according to any one of [1] to

[15] .

[17] Laminated glass comprising a first glass plate, a second glass plate, and an interlayer sandwiched between the first glass plate and the second glass plate, wherein the first glass plate is the vehicle and sensor glass described in any one of [1] to

[15] .

[18] The laminated glass according to

[17] , wherein the surface roughness Ra of the first glass plate is 5.0 nm or less, the thickness is 2.5 mm, and the critical impact fracture velocity when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted onto the surface of the first glass plate is 40 km / h or more.

[19] The laminated glass according to

[17] or

[18] , wherein the critical impact fracture velocity when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted onto the surface of the first glass plate is 60 km / h or more.

[20] Laminated glass according to any one of

[17] to

[19] , wherein the sum of the thicknesses of the first glass plate, the second glass plate, and the interlayer is 4.5 mm or more.

[21] Thickness t of the first glass plate １ and the thickness t of the second glass plate ２ The ratio (t) １ / t ２Laminated glass according to any one of

[17] to

[20] , wherein the ratio is 1.5 or higher.

[22] Laminated glass comprising a first glass plate, a second glass plate, and an interlayer sandwiched between the first glass plate and the second glass plate, wherein the first glass plate and the second glass plate are vehicle and sensor glass according to any one of [1] to

[15] .

[23] Laminated glass according to any one of

[17] to

[22] , wherein the second glass plate is soda-lime glass.

[24] Laminated glass according to any one of

[17] to

[22] , wherein the second glass plate is alkali aluminosilicate glass.

[25] Laminated glass according to any one of

[17] to

[24] , wherein the second glass plate is chemically strengthened.

[0011] According to this disclosure, it is possible to provide automotive and sensor glass, bendable glass, and laminated glass that have excellent fracture toughness, as well as low viscosity and low density.

[0012] Figure 1 shows B in glass. ２ O ３ This graph shows the relationship between the content of converted three-coordinate or four-coordinate boron and Young's modulus. Figure 2 shows the relationship between B in glass. ２ O ３ This graph shows the relationship between the content of converted three-coordinate or four-coordinate boron and the surface fracture energy. Figure 3 shows the relationship between ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ] and B ２ O ３ This graph shows the relationship with the content of three-coordinate boron in conversion. Figure 4 shows ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ] and B ２ O ３It is a graph showing the relationship with the content of the 3 - coordinate boron in conversion. FIG. 5 is a cross - sectional view of an example of the laminated glass according to an embodiment of the present invention. FIG. 6 is a conceptual diagram showing a state where the laminated glass according to an embodiment of the present invention is used as a window glass for a vehicle. FIG. 7 is an enlarged view of the S portion in FIG. 6. FIG. 8 is a cross - sectional view taken along the Y - Y line of FIG. 7.

[0013] Hereinafter, the present invention will be described in detail based on embodiments, but the present invention is not limited to these embodiments. Also, in the following drawings, members and parts having the same function may be denoted by the same reference numerals for explanation, and redundant explanations may be omitted or simplified. In addition, the embodiments shown in the drawings are schematized for clearly explaining the present invention, and do not necessarily accurately represent the size and scale of actual products. Also, in this specification, a numerical range indicated using "~" represents a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively.

[0014] <Glass composition> In this embodiment, in terms of mol% based on oxides, it does not substantially contain Li ２ O, and contains ２ SiO ２ : 70.0 - 80.0% ３ B ２ O ３ : 10.0 - 17.0% ２ Al ２ O ２ : 1.0 - 6.0% ２ MgO: 0.0 - 5.0% ２ CaO: 0.0 - 5.0% ２ SrO: 0.0 - 5.0% ２ BaO: 0.0 - 5.0% ２ Na ３ O: 0.0 - 19.0% ２ K ３ O: 0.0 - 10.0% ２ R' ２ O: 6.0 - 19.0% ２ RO: 0.0 - 5.0% (where RO is the total content of MgO, CaO, SrO and BaO, and ２ R' ２ O is the total content of ２ Na ３ O and ２ K ３ O) and contains (([R' ２ O] + 1 / 2[RO] - [Al ２ O ３ ) - [B ２ O ３The present invention provides vehicle and sensor glass (hereinafter referred to as "glass of the first embodiment") having a value of ≥ -6.5.

[0015] Furthermore, in this embodiment, the SiO is expressed in mole percent based on oxides. ２ :70.0~80.0%B ２ O ３ :10.0~17.0% Al ２ O ３ :1.0~6.0% MgO:0.0~5.0% CaO:0.0~5.0% SrO:0.0~5.0% BaO:0.0~5.0% Li ２ O: more than 0.0 to 15.0% Na ２ O: 3.5-15.0% K ２ O: 0.0 to 10.0% R ２ O: 6.0–19.0% RO: 0.0–5.0% (However, RO is the total content of MgO, CaO, SrO and BaO, R ２ O is Li ２ O, Na ２ O and K ２ It contains (the total amount of O), ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ The present invention provides vehicle and sensor glass (hereinafter referred to as "glass of the second embodiment") having a value of ≥ -10.0.

[0016] In this specification, "glass of this embodiment" includes the glass of the first embodiment and the glass of the second embodiment.

[0017] The composition range of each component is expressed in mole percent based on oxides unless otherwise specified. Furthermore, "substantially absent" for each component means that, unless otherwise specified, it is not present except for unavoidable impurities introduced from raw materials, etc., i.e., intentionally omitted.

[0018] Hereinafter, as specific embodiments of the glass for vehicles and sensors (hereinafter sometimes simply referred to as "glass") of the present embodiment, the glass of the first embodiment and the glass of the second embodiment will be described.

[0019] [Glass of the First Embodiment] The glass of the first embodiment contains substantially no Li ２ O in terms of mol% based on oxides, and contains ２ SiO ２ : 70.0 to 80.0% ３ B ２ O ３ : 10.0 to 17.0% ２ Al ２ O ２ : 1.0 to 6.0% ２ MgO: 0.0 to 5.0% ２ CaO: 0.0 to 5.0% ２ SrO: 0.0 to 5.0% ２ BaO: 0.0 to 5.0% ２ Na ３ O: 0.0 to 19.0% ２ K ３ O: 0.0 to 10.0% ２ R' ２ O: 6.0 to 19.0% ２ RO: 0.0 to 5.0% (where RO is the total content of MgO, CaO, SrO, and BaO, and R' ２ O is the total content of Na ２ O and K ２ O), and satisfies ([R' ２ O] + 1 / 2[RO] - [Al ３ O ２ ) - [B ３ O ２ ≥ -6.5. It is a glass for vehicles and sensors. Here, [] represents the content in terms of mol% based on oxides of each component within the parentheses.

[0020] ３ SiO ２ is a component that constitutes the network structure of the glass and is an essential component of the glass of the present embodiment. In the glass of the first embodiment, the content of ３ SiO ２ is 70.0 to 80.0%. In the glass of the first embodiment, ３ SiO ２When the content of ２ is 70.0% or more, the structure of the glass becomes strong, and the Young's modulus can be increased. In addition, it is easy to reduce the density of the glass, and furthermore, moisture resistance and chemical durability can be ensured. Furthermore, the viscosity of the glass can be reduced. Also, an increase in the average linear expansion coefficient can be suppressed, and thermal cracking of the glass can be suppressed. SiO

[0021] Also, in the glass of the first embodiment, SiO ２ When the content of ２ is 80.0% or less, an increase in viscosity during glass melting is suppressed, glass manufacturing becomes easy, and the formability of vehicle glass, particularly windshield and cover glass for sensors, etc. is improved. The content of SiO

[0022] In this embodiment, B ２ O ３ reduces the viscosity and density of the glass and also contributes to an improvement in the Young's modulus. It is also a component for controlling optical properties. The glass of the first embodiment contains B ２ O ３ in an amount of 10.0 to 17.0%. By containing B ２ O ３ in the glass of the first embodiment in an amount of 10.0% or more, the viscosity and density of the glass can be reduced. Also, as described later, by controlling the coordination number of boron, the Young's modulus can be increased. In the glass of the first embodiment, the content of B ２ O ３ is preferably 11.0% or more, more preferably 12.0% or more, and still more preferably 13.0% or more.

[0023] Also, in the glass of the first embodiment, B ２ O ３If the content is 17.0% or less, alkali elements are less likely to volatilize during the melting and molding of the glass, thus suppressing the deterioration of glass quality. Furthermore, acid resistance and alkali resistance can be improved. B ２ O ３ The content of is preferably 16.0% or less, more preferably 15.0% or less, and even more preferably 14.0% or less.

[0024] Furthermore, in the glass of the first embodiment, B ２ O ３ Converted content of three-coordinate boron (B ３ as B ２ O ３ Preferably, the amount is 10.0 mol% or less. The inventors have found that by adjusting the ratio of 3-coordinate boron to 4-coordinate boron contained in the glass, a glass with a high Young's modulus and excellent fracture toughness can be obtained.

[0025] Boron can have three- or four-coordinate oxygen atoms in glass. Four-coordinate boron enters the glass framework and takes on a tetrahedral structure. In this case, the tetrahedral structure is negatively charged, and the charge is compensated for by alkali metal ions or alkaline earth metal ions. Therefore, four-coordinate boron forms a three-dimensional glass structure with almost no unbridged oxygen atoms being generated. On the other hand, three-coordinate boron has unbridged oxygen atoms in glass and is known to take on planar structures such as cyclic structures (boroxol rings).

[0026] Figure 1 shows B in glass. ２ O ３ This graph shows the relationship between the content of converted three-coordinate boron or four-coordinate boron and Young's modulus. As shown in Figure 1, the Young's modulus tends to decrease as the content of three-coordinate boron increases, and to increase as the content of four-coordinate boron increases. The reason why Young's modulus improves with increasing content of four-coordinate boron is thought to be that as the proportion of three-coordinate boron decreases and the proportion of four-coordinate boron increases, the amount of non-bridged oxygen decreases and a denser structure is formed, which increases the ion packing efficiency and bond dissociation energy that contribute to Young's modulus.

[0027] Figure 2 also shows B in glass. ２ O３ This graph shows the relationship between the content of converted three-coordinate boron or four-coordinate boron and the surface fracture energy. As shown in Figure 2, the surface fracture energy tends to increase as the content of four-coordinate boron increases, and decrease as the content of three-coordinate boron increases.

[0028] Next, the fracture toughness value K ＩＣ The relationship between Young's modulus and surface fracture energy will be explained. Fracture toughness value K ＩＣ K is an indicator of glass strength, representing the fracture toughness value. ＩＣ The larger the value, the more effectively the propagation of cracks in the glass can be suppressed. Fracture toughness value K ＩＣ (Pa・m １／２ ) is Young's modulus E (Pa), surface fracture energy γ (J / m ２ It can be calculated from ) and Poisson's ratio ν (unitless) by the following formula (1).

[0029]

[0030] As shown in formula (1) above, the fracture toughness value K ＩＣ The value of this factor increases as Young's modulus E and surface fracture energy γ increase.

[0031] As shown in Figures 1 and 2, the Young's modulus and surface fracture energy of the glass improve as the content of four-coordinate boron increases. Therefore, in this embodiment, the glass with higher fracture toughness is obtained as the boron exists in a four-coordinate state. Accordingly, in the glass of the first embodiment, B ２ O ３ The converted content of three-coordinate boron is preferably 10.0% or less, more preferably 9.0% or less, even more preferably 8.0% or less, even more preferably 7.0% or less, particularly preferably 6.0% or less, and most preferably 5.0% or less.

[0032] Furthermore, from the viewpoint of suppressing the increase in viscosity associated with the increase in glass network formation by four-coordinate boron, B ２ O ３The converted content of three-coordinate boron is preferably more than 0.0%, more preferably 0.2% or more, even more preferably 1.5% or more, even more preferably 2.0% or more, and particularly preferably 2.5% or more. ２ O ３ The converted content of three-coordinate boron may be, for example, more than 0.0% and 10.0% or less, more than 0.0% and 7.0% or less, more than 0.0% and 6.0% or less, or between 0.2% and 5.0%.

[0033] Note that the glass in this embodiment is Fe ２ O ３ When this material is present, the color tone of the glass can be adjusted by adjusting the ratio of three-coordinate boron to four-coordinate boron. Specifically, the higher the proportion of four-coordinate boron, the stronger the gray color of the glass becomes, resulting in glass with superior design appeal. Since the resulting glass has a gray color, it is more suitable for applications such as vehicle windows. From this viewpoint, it is preferable that the glass of the first embodiment has a three-coordinate boron content within the above range.

[0034] In the glass of the first embodiment, B ２ O ３ From the viewpoint of obtaining glass with high fracture toughness, the converted content of four-coordinate boron is preferably 3.0% or more, preferably 5.0% or more, more preferably 6.0% or more, even more preferably 7.0% or more, even more preferably 9.5% or more, particularly preferably 9.7% or more, and most preferably 9.8% or more.

[0035] Furthermore, from the viewpoint of suppressing the increase in viscosity associated with the increase in glass network formation by four-coordinate boron, B ２ O ３ The converted content of four-coordinate boron is preferably less than 17.0%, preferably 15.0% or less, more preferably 14.0% or less, and particularly preferably 13.0% or less. ２ O ３ The converted content of four-coordinate boron may be, for example, 5.0% or more and less than 17.0%, 9.5% to 15.0%, 9.7% to 14.0%, or 9.8% to 13.0%.

[0036] In the glass of the first embodiment, the content of three-coordinate boron is B ２ O ３ The converted amount is greater than 0.0% and less than or equal to 7.0%, and the content of four-coordinate boron is B ２ O ３ It is preferable that the converted amount is 9.5 to 15.0%. Also, the content of three-coordinate boron is B ２ O ３ The converted amount is greater than 0.0% and less than or equal to 6.0%, and the content of four-coordinate boron is B ２ O ３ A conversion of 9.7% to 14.0% is more preferable.

[0037] As described above, boron can have a three-coordinate or four-coordinate oxygen coordination number in glass. Therefore, in the glass of the first embodiment, B ２ O ３ Converted content of three-coordinate boron and B ２ O ３ The total amount of converted four-coordinate boron is as described above in B ２ O ３ It matches the content of [the substance].

[0038] The ratio of three-coordinate boron to four-coordinate boron can be adjusted by the composition of the glass. Specifically, alkali metal oxides and alkaline earth metal oxides, Al ２ O ３ This can be adjusted by appropriately adjusting the content of [the substance].

[0039] As mentioned above, boron in glass exists as a tetrahedral structure (four-coordinate boron) when its charge is compensated by alkali metal ions or alkaline earth metal ions. On the other hand, boron that is not coordinated to alkali metal ions exists as three-coordinate boron. Therefore, the ratio of three-coordinate boron to four-coordinate boron can be adjusted by controlling the alkali metal ion content.

[0040] Also, at this time, Al ２ O ３The content of these elements also needs to be considered. Al is known to take on 4 to 6 coordination numbers with oxygen in glass, and 4-coordinate Al forms a glass structure as a tetrahedron. Since 4-coordinate Al, like 4-coordinate boron, has a negative charge, its charge is compensated for by alkali metal ions and alkaline earth metal ions. In this case, alkali metal ions tend to coordinate to Al preferentially over boron.

[0041] Specifically, Al ２ O ３ and alkali metal oxides and B ２ O ３ In the case of glass with an alkali metal content ratio of 1:1:1, almost all of the alkali metal oxides are consumed in the four-coordinate formation of Al. Therefore, in the above case, almost all of the boron in the glass exists as three-coordinate boron.

[0042] Similarly, alkaline earth metal oxides also affect the coordination number of boron, just like alkali metal oxides. In particular, ions with lower electronegativity tend to react with boron more readily, increasing the proportion of four-coordinate boron. Therefore, in the order of increasing electronegativity, Ba, Sr, Ca, and Mg tend to increase the proportion of four-coordinate boron.

[0043] Therefore, the content of three-coordinate boron and four-coordinate boron is determined by alkali metal oxides and alkaline earth metal oxides, Al ２ O ３ The content can be adjusted by controlling the amount of each component. Furthermore, the content of three-coordinate boron and four-coordinate boron can also be adjusted by controlling the average cooling rate, as described later.

[0044] The proportions of three-coordinate boron and four-coordinate boron in the glass can be measured by nuclear magnetic resonance (NMR). For details, please refer to the methods described in the examples below.

[0045] Al ２ O ３ Al is a component that constitutes the mesh structure of the glass and is an essential component of the glass in this embodiment. The glass in the first embodiment is Al ２ O ３ It contains 1.0 to 6.0% of Al. ２ O３ A content of 1.0% or more can increase the Young's modulus. In addition, weather resistance, moisture resistance, and chemical durability are improved. Furthermore, the average coefficient of linear expansion does not become too large, which can suppress thermal cracking of the glass, and chemical strengthening treatment using ion exchange becomes possible. Al ２ O ３ The content is preferably 1.1% or more, and more preferably 1.2% or more. ２ O ３ The content may be, for example, 1.5% or more, 1.8% or more, 2.0% or more, 2.3% or more, or 2.5% or more.

[0046] Furthermore, in the glass of the first embodiment, Al ２ O ３ By keeping the content of 6.0% or less, the increase in viscosity during glass melting is suppressed, making glass manufacturing easier, and improving the moldability of vehicle glass, especially windshields and sensor cover glass. Furthermore, the content of alkali metals that coordinate to boron increases, and the proportion of three-coordinate boron can be reduced. ２ O ３ The content of is preferably 5.5% or less, more preferably 5.0% or less, even more preferably 4.5% or less, particularly preferably 4.0% or less, particularly preferably 3.5% or less, particularly preferably 3.0% or less, particularly preferably 2.6% or less, particularly preferably 2.5% or less, and most preferably 2.0% or less.

[0047] The composition of the glass in the first embodiment is expressed in mole percent on an oxide basis as SiO ２ , B ２ O ３ and Al ２ O ３ Total content (SiO ２ +B ２ O ３ +Al ２ O ３ Preferably, the content is 81.0 to 93.0%. SiO ２ +B ２ O ３ +Al ２ O ３When the concentration is 81.0% or higher, the effects of each component mentioned above are realized, and the formability and chemical durability of the glass are excellent. ２ +B ２ O ３ +Al ２ O ３ It is more preferable that the content be 82.0% or more, and even more preferable that it be 83.0% or more. Also, SiO ２ +B ２ O ３ +Al ２ O ３ When the concentration is 93.0% or less, the effects of each component described above are more favorably achieved. SiO ２ +B ２ O ３ +Al ２ O ３ It is more preferable that the percentage be 92.0% or less, even more preferable that it be 91.0% or less, even more preferable that it be 89.0% or less, and particularly preferable that it be 88.0% or less.

[0048] In this embodiment, MgO is a component that reduces the viscosity of the glass and further contributes to improving the Young's modulus. Furthermore, as mentioned above, it is a component that increases the proportion of three-coordinate boron due to its high electronegativity. The glass of the first embodiment contains 0.0 to 5.0% MgO. By including MgO in the glass of the first embodiment, the viscosity of the glass can be reduced and the dissolution of the glass raw material can be promoted. In addition, the Young's modulus and moisture resistance can be improved. When MgO is included in the glass of the first embodiment, the content is preferably 0.20% or more, more preferably 0.40% or more, even more preferably 0.60% or more, particularly preferably 0.80% or more, and most preferably 1.0% or more.

[0049] Furthermore, in the glass of the first embodiment, if the MgO content is 5.0% or less, the glass becomes less prone to devitrification, and an excessive increase in viscosity during glass melting is suppressed, making glass manufacturing easier. In addition, the moldability of vehicle glass, especially windshields and cover glass for sensors, is improved. Moreover, the proportion of three-coordinate boron can be kept low. The MgO content is preferably 4.0% or less, more preferably 3.5% or less, even more preferably 3.0% or less, particularly preferably 2.5% or less, and most preferably 2.0% or less.

[0050] In this embodiment, CaO is a component that reduces the viscosity of the glass. In addition, since it has a high electronegativity as described above, it is a component that increases the proportion of boron coordinated in three positions. The glass of the first embodiment contains 0.0 to 5.0% of CaO. By including CaO in the glass of the first embodiment, the solubility of the raw materials of the glass is improved, and since the viscosity further decreases, the formability of vehicle glass, particularly windshield glass and cover glass for sensors, etc. is improved. When including CaO in the glass of the first embodiment, the content is preferably 0.20% or more, more preferably 0.40% or more, still more preferably 0.60% or more, particularly preferably 0.80% or more, and most preferably 1.0% or more.

[0051] Further, in the glass of the first embodiment, by setting the content of CaO to 5.0% or less, an increase in the density of the glass can be suppressed, the average linear expansion coefficient can be reduced, and thermal cracking of the glass can be suppressed. Furthermore, the proportion of boron coordinated in three positions can be kept low. The content of CaO in the glass of the first embodiment is preferably 4.0% or less, more preferably 3.5% or less, still more preferably 3.0% or less, particularly preferably 2.5% or less, and most preferably 2.0% or less.

[0052] In this embodiment, SrO is a component that reduces the viscosity of the glass. Also, since Sr has a lower electronegativity than Mg and Ca, the proportion of boron coordinated in four positions can be increased. The glass of the first embodiment contains 0.0 to 5.0% of SrO. In the glass of the first embodiment, by setting the content of SrO to 5.0% or less, an increase in the density of the glass can be suppressed. In the glass of the first embodiment, the content of SrO is preferably 4.0% or less, more preferably 3.0% or less, still more preferably 2.0% or less, even more preferably 1.0% or less, particularly preferably 0.5% or less, and most preferably substantially not contained. Substantially not containing SrO in the glass of the first embodiment means that the content of SrO in the glass is 0.10 mol% or less.

[0053] In the glass of the first embodiment, if SrO is included, the SrO content may be 0.20% or more, 0.40% or more, 0.60% or more, 0.80% or more, or 1.0% or more. By including SrO, the viscosity of the glass can be reduced, and the proportion of four-coordinate boron can be increased.

[0054] In this embodiment, BaO is a component that reduces the viscosity of the glass. Also, because Ba has a lower electronegativity than Mg and Ca, it can increase the proportion of four-coordinate boron. The glass of the first embodiment contains 0.0 to 5.0% BaO. In the glass of the first embodiment, the increase in density of the glass can be suppressed by reducing the BaO content to 5.0% or less. In the glass of the first embodiment, the BaO content is preferably 4.0% or less, more preferably 3.0% or less, even more preferably 2.0% or less, even more preferably 1.0% or less, particularly preferably 0.5% or less, and most preferably substantially absent. Substantially absent BaO in the glass of the first embodiment means that the BaO content in the glass is 0.10 mol% or less.

[0055] In the glass of the first embodiment, if BaO is included, the BaO content may be 0.20% or more, 0.40% or more, 0.60% or more, 0.80% or more, or 1.0% or more. By including BaO, the viscosity of the glass can be reduced, and the proportion of four-coordinate boron can be increased.

[0056] In this embodiment, Na ２ O is a component that improves the solubility of glass and reduces its viscosity. It also makes it easier to increase Young's modulus and contributes to the average coefficient of linear thermal expansion of glass. Furthermore, the strength of the glass can be increased by chemical strengthening treatment through ion exchange with K ions. In addition, the proportion of four-coordinate boron can be increased by the coordination of Na ions with boron.

[0057] In the glass of the first embodiment, Na ２The O content is 0.0 to 19.0%. In the glass of the first embodiment, Na ２ The inclusion of O can reduce the viscosity of the glass and further increase the proportion of four-coordinate boron. In addition, it can increase Young's modulus and mean coefficient of linear expansion. Na ２ If O is present, its content is preferably 2.0% or more, more preferably 3.0% or more, even more preferably 4.0% or more, even more preferably 5.0% or more, even more preferably more than 5.0%, especially preferably 5.5% or more, particularly preferably 6.0% or more, and most preferably 6.5% or more.

[0058] Also, Na ２ By keeping the O content below 19.0%, thermal cracking of the glass caused by an excessively large average coefficient of linear expansion can be suppressed. Furthermore, the improved moisture resistance of the glass makes it suitable for applications such as vehicle windows that are exposed to the atmosphere for extended periods. Na ２ The O content is preferably 17.0% or less, more preferably 15.0% or less, even more preferably 13.0% or less, even more preferably 12.5% ​​or less, particularly preferably 12.0% or less, and most preferably 11.5% or less. ２ The O content may be 11.0% or less, or 10.0% or less.

[0059] K ２ O is a component that improves the solubility of glass and reduces viscosity, and also makes it easier to increase Young's modulus, and contributes to the average coefficient of linear expansion of glass. In the glass of the first embodiment, K ２ The oxygen content is 0.0 to 10.0%.

[0060] In the glass of the first embodiment, K ２ By including oxygen (O), the viscosity of the glass can be reduced. In addition, the Young's modulus and mean coefficient of linear expansion can be increased. Furthermore, the K ion coordinates with boron, increasing the proportion of four-coordinate boron. ２ If oxygen is included, the amount is preferably 0.10% or more, more preferably 0.20% or more, even more preferably 0.30% or more, particularly preferably 0.40% or more, and most preferably 0.50% or more.

[0061] On the other hand, K ２ O is Li ２ O and Na ２ Compared to O, it has the effect of increasing the average coefficient of linear expansion and density. ２ By keeping the O content below 10.0%, thermal cracking of the glass caused by an excessively large average coefficient of linear thermal expansion can be suppressed. ２ The O content is preferably 8.0% or less, more preferably 6.0% or less, even more preferably 5.0% or less, even more preferably 4.0% or less, particularly preferably 3.0% or less, and most preferably 2.0% or less.

[0062] In the glass of the first embodiment, Na ２ O and K ２ Total content of O (hereinafter, R') ２ (Sometimes referred to as O) is between 6.0% and 19.0%. ２ A higher O content of 6.0% or more increases the Young's modulus and further reduces the viscosity of the glass, thereby improving the moldability of vehicle glass, especially windshields and sensor cover glass. ２ The amount of O is preferably 6.5% or more, more preferably 7.0% or more, even more preferably 7.5% or more, particularly preferably 8.0% or more, and most preferably 8.5% or more.

[0063] Also, R' ２ If the oxygen content is 19.0% or less, the increase in density can be suppressed, and the moisture resistance of the glass can be improved. ２ O is preferably 17.0% or less, more preferably 15.0% or less, even more preferably 14.0% or less, even more preferably 13.0% or less, particularly preferably 12.0% or less, and most preferably 11.0% or less.

[0064] In the glass of the first embodiment, the total content of MgO, CaO, SrO, and BaO (hereinafter sometimes referred to as RO) is 0.0% or more and 5.0% or less. By including at least one selected from MgO, CaO, SrO, and BaO, the Young's modulus can be improved. When RO is included, the RO content is preferably 0.20% or more, more preferably 0.40% or more, even more preferably 0.60% or more, particularly preferably 0.80% or more, and most preferably 1.0% or more.

[0065] Furthermore, if the RO is 5.0% or less, the increase in glass density can be suppressed, improving the crack resistance of the glass. The RO is preferably 4.5% or less, more preferably 4.0% or less, even more preferably 3.5% or less, even more preferably 3.0% or less, particularly preferably 2.5% or less, and most preferably 2.0% or less.

[0066] Furthermore, the glass of the first embodiment is Li ２ It substantially does not contain O. In the glass of the first embodiment, Li ２ By substantially omitting O, the formation of a Li-containing crystalline phase during glass manufacturing can be suppressed, thereby improving manufacturability. In the glass of the first embodiment, Li ２ Substantially O-free means that Li in the glass ２ This means that the oxygen content is 0.10 mol% or less.

[0067] In the glass of the first embodiment, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ] is -6.5 or higher. Here, [] represents the content of each component in parentheses in mole percent based on oxide. ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ When the value of ] is -6.5 or higher, the proportion of three-coordinate boron in the glass is reduced, improving Young's modulus and surface fracture energy, and as a result, the fracture toughness value can be improved.

[0068] As mentioned above, the ratio of three-coordinate boron to four-coordinate boron in glass is due to alkali metal oxides and alkaline earth metal oxides, Al ２ O ３ It can be adjusted by the content of [R'], as shown in Figure 3, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ The larger the value of [ ], the lower the content of three-coordinate boron tends to be.

[0069] In the glass of the first embodiment, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ If [R'] is -6.5 or higher, the content of three-coordinate boron can be sufficiently reduced, and the fracture toughness of the glass can be increased. ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ [R'] is preferably greater than -3.0, more preferably -2.5 or greater, and even more preferably -2.2 or greater. ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ For example, ] may be -6.2 or higher, -6.0 or higher, -5.8 or higher, -5.6 or higher, -5.4 or higher, and -5.2 or higher.

[0070] Furthermore, from the viewpoint of suppressing the increase in the viscosity of the glass and deterioration of its bendability due to an excessive proportion of four-coordinate boron, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ [R'] is preferably 0.0 or less, more preferably -1.0 or less, and even more preferably -1.5 or less. ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２O ３ For example, ] may be -1.7 or less, -2.0 or less, or -2.5 or less.

[0071] [Glass of the second embodiment] The glass of the second embodiment has a molar content of SiO2, expressed as an oxide-based molar percentage. ２ :70.0~80.0%B ２ O ３ :10.0~17.0% Al ２ O ３ :1.0~6.0% MgO:0.0~5.0% CaO:0.0~5.0% SrO:0.0~5.0% BaO:0.0~5.0% Li ２ O: more than 0.0 to 15.0% Na ２ O: 3.5-15.0% K ２ O: 0.0 to 10.0% R ２ O: 6.0–19.0% RO: 0.0–5.0% (However, RO is the total content of MgO, CaO, SrO and BaO, R ２ O is Li ２ O, Na ２ O and K ２ It contains (the total amount of O), ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ] ≥ -10.0.

[0072] In the glass of the second embodiment, SiO ２ , B ２ O ３ Al ２ O ３ SiO ２ +B ２ O ３ +Al ２ O ３ , MgO, CaO, SrO, BaO, K ２ With respect to O and RO, they are the same as the glass in the first embodiment.

[0073] In the glass of the second embodiment, Li ２O is a component that improves the solubility of glass and reduces its viscosity. In addition, it is a component that increases Young's modulus and contributes to the average coefficient of linear expansion of glass. Furthermore, the strength of the glass can be increased by chemical strengthening treatment through ion exchange with Na ions. Also, the proportion of four-coordinate boron can be increased by Li ions coordinating with boron. The glass of the second embodiment is Li ２ It contains more than 0.0% to 15.0% oxygen.

[0074] In the glass of the second embodiment, Li ２ By containing O, Na ２ O and K ２ Compared to O, it can lower the viscosity of the glass and increase the Young's modulus. Furthermore, it can increase the proportion of 4-coordinate boron, so Na ２ O and K ２ Compared to O, it can potentially increase Young's modulus and fracture toughness. ２ The O content is preferably 0.50% or more, more preferably 1.0% or more, even more preferably 1.5% or more, even more preferably 2.0% or more, particularly preferably 2.5% or more, and most preferably 3.0% or more.

[0075] Furthermore, in the glass of the second embodiment, Li ２ By keeping the O content at 15.0% or less, thermal cracking of the glass caused by an excessively large average coefficient of linear expansion can be suppressed. Furthermore, the formation of a Li-containing crystalline phase during glass manufacturing is suppressed, improving the manufacturability of the glass. In the glass of the second embodiment, Li ２ The O content is preferably 12.0% or less, more preferably 10.0% or less, even more preferably 8.0% or less, particularly preferably 6.0% or less, and most preferably 5.0% or less.

[0076] In the glass of the second embodiment, Na ２ It contains 3.5-15.0% O. ２ Because the O content is 3.5% or more, the viscosity of the glass decreases, so Li is used during the manufacturing of the glass. ２The oxygen content can be reduced, and the formation of a crystalline phase containing lithium during glass manufacturing can be suppressed. Furthermore, the viscosity of the glass is reduced, improving the moldability of vehicle glass, especially windshields and cover glass for sensors. In addition, the proportion of four-coordinate boron can be increased, improving Young's modulus and surface fracture energy. ２ The O content is preferably 4.0% or more, more preferably 4.5% or more, even more preferably 5.0% or more, even more preferably more than 5.0%, even more preferably 5.5% or more, especially preferably 6.0% or more, particularly preferably 6.5% or more, and most preferably 7.0% or more.

[0077] Furthermore, in the glass of the second embodiment, Na ２ By keeping the O content below 15.0%, the average coefficient of linear thermal expansion can be reduced, suppressing thermal cracking of the glass. Furthermore, the improved moisture resistance of the glass makes it suitable for applications such as vehicle glass and sensor glass, which are exposed to the atmosphere for extended periods. Na ２ The O content is preferably 13.0% or less, more preferably 12.0% or less, even more preferably 11.0% or less, particularly preferably 10.0% or less, and most preferably 9.0% or less.

[0078] In the glass of the second embodiment, Li ２ O, Na ２ O and K ２ Total content of O (hereinafter, R ２ (Sometimes referred to as O) is 6.0-19.0%. ２ A higher O content of 6.0% or more increases the Young's modulus and further reduces the viscosity of the glass, thereby improving the moldability of vehicle glass, especially windshields and sensor cover glass. ２ The amount of O is preferably 6.5% or more, more preferably 7.0% or more, even more preferably 7.5% or more, even more preferably 8.0% or more, particularly preferably 8.5% or more, and most preferably 9.0% or more.

[0079] R ２From the viewpoint of improving moisture resistance and suppressing an increase in density, the amount of oxygen (O) is 19.0% or less, preferably 17.0% or less, more preferably 15.0% or less, even more preferably 14.0% or less, even more preferably 13.0% or less, particularly preferably 12.0% or less, and most preferably 11.0% or less.

[0080] Furthermore, in the glass of the second embodiment, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ] is -10.0 or greater. Here, [] represents the content of each component in parentheses in mole percent based on oxide. In the glass of the second embodiment, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ When the ratio is -10.0 or higher, the proportion of three-coordinate boron in the glass is reduced, improving Young's modulus and surface fracture energy, and as a result, the fracture toughness value can be improved.

[0081] As mentioned above, the ratio of three-coordinate boron to four-coordinate boron in glass is due to alkali metal oxides and alkaline earth metal oxides, Al ２ O ３ It can be adjusted by the content of [R], as shown in Figure 4, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ The larger the value of [ ], the lower the content of three-coordinate boron tends to be.

[0082] In the glass of the second embodiment, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ If [R] is -10.0 or higher, the content of three-coordinate boron can be sufficiently reduced, and the fracture toughness value of the glass can be increased. ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２O ３ [R] is preferably greater than -3.0, more preferably greater than -2.5, even more preferably greater than -2.3, and even more preferably greater than -2.0. ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ For example, ] may be -9.0 or higher, -8.0 or higher, -7.5 or higher, -7.0 or higher, -6.5 or higher, and -6.0 or higher.

[0083] Furthermore, in order to suppress the increase in the viscosity of the glass and deterioration of its bendability due to an excessive proportion of four-coordinate boron, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ [R] is preferably less than 0.0, more preferably -0.3 or less, even more preferably -0.4 or less, and most preferably -0.5 or less. ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ For example, ] may be -1.0 or less, -1.5 or less, or -2.0 or less.

[0084] In the glass of the second embodiment, B ２ O ３ Converted content of three-coordinate boron (B ３ as B ２ O ３ Preferably, the amount is 10.0 mol% or less. As described above, in the glass of this embodiment, the Young's modulus and surface fracture energy improve as the content of four-coordinate boron increases, so a higher fracture toughness value can be obtained as boron exists in a four-coordinate state. Therefore, in the glass of the second embodiment, B ２ O ３ The converted content of three-coordinate boron is preferably 10.0% or less, more preferably 9.0% or less, even more preferably 8.0% or less, even more preferably 7.0% or less, particularly preferably 6.5% or less, and most preferably 6.0% or less.

[0085] Furthermore, in the glass of the second embodiment, from the viewpoint of suppressing the increase in viscosity associated with the increase in glass network formation by four-coordinate boron, B ２ O ３ The converted content of three-coordinate boron is preferably more than 0.0%, preferably 1.0% or more, more preferably 1.5% or more, particularly preferably 2.0% or more, and most preferably 2.5% or more. ２ O ３ The converted content of three-coordinate boron may be, for example, more than 0.0% and 10.0% or less, more than 0.0% and 7.0% or less, more than 0.0% and 6.5% or less, or between 1.5% and 6.0%.

[0086] In the glass of the second embodiment, B ２ O ３ The converted content of four-coordinate boron is the same as that of the glass in the first embodiment.

[0087] In the glass of the second embodiment, the content of three-coordinate boron is B ２ O ３ The converted amount is greater than 0.0% and less than or equal to 7.0%, and the content of four-coordinate boron is B ２ O ３ It is preferable that the converted amount is 9.5 to 15.0%. Also, the content of three-coordinate boron is B ２ O ３ The converted amount is greater than 0.0% and less than or equal to 6.5%, and the content of four-coordinate boron is B ２ O ３ A conversion of 9.7% to 14.0% is more preferable.

[0088] The following describes the components and properties of the glass of this embodiment, including the first and second embodiments, other than those mentioned above.

[0089] [Other ingredients] Fe ２ O ３ This component improves the heat-shielding properties of the glass and also contributes to the color of the glass, so it may be included in the glass of this embodiment. In the glass of this embodiment, Fe ２ O ３The total iron content, converted to iron, is preferably 0.0025 to 1.2%. ２ O ３ The total iron content converted to this means that FeO, an oxide of divalent iron, and Fe, an oxide of trivalent iron. ２ O ３ This refers to the total amount of iron, including Fe. ２ O ３ The inclusion of this ingredient makes it suitable for applications requiring heat shielding. Furthermore, it can suppress the load on the melting furnace caused by heat radiation reaching the bottom of the melting furnace during glass melting.

[0090] When using the glass of this embodiment for vehicle glass, from the viewpoint of improving heat shielding, adding design features, and facilitating heat transfer to the glass during bending and forming, the Fe in the glass of this embodiment ２ O ３ The total iron content, converted to iron, is preferably 0.0025% or more, more preferably 0.0040% or more, even more preferably 0.039% or more, even more preferably 0.097% or more, especially preferably 0.11% or more, particularly preferably 0.15% or more, and most preferably 0.17% or more.

[0091] Furthermore, from the viewpoint of suppressing the decrease in light transmittance in the visible range, Fe ２ O ３ The total iron content, converted to iron, is preferably 1.2% or less, more preferably 1.0% or less, even more preferably 0.80% or less, even more preferably 0.60% or less, particularly preferably 0.50% or less, and most preferably 0.40% or less.

[0092] On the other hand, when using the glass of this embodiment for LiDAR or camera cover glass, from the viewpoint of facilitating the melting of raw materials during glass manufacturing and reducing the amount of expensive high-purity raw materials used, Fe ２ O ３ The total iron content, converted to iron, is preferably 0.0030% or more, more preferably 0.0032% or more, even more preferably 0.0034% or more, even more preferably 0.0036% or more, especially preferably 0.0038% or more, particularly preferably 0.0040% or more, and most preferably 0.0042% or more.

[0093] Furthermore, from the viewpoint of suppressing the decrease in light transmittance in the visible and near-infrared regions, Fe ２ O ３ The total iron content, converted to iron, is preferably 0.020% or less, more preferably 0.010% or less, even more preferably 0.0080% or less, particularly preferably 0.0070% or less, and most preferably 0.0060% or less.

[0094] The glass of this embodiment is Fe ２ O ３ Fe in total iron converted ２ O ３ It is preferable that the mass percentage (%) of divalent iron converted to (hereinafter referred to as Fe-Redox) is 15.0% or more. The value of Fe-Redox is Fe ２ O ３ Fe relative to the total iron content (converted) ２ O ３ Fe conversion ２＋ This is the percentage of the content.

[0095] The glass of this embodiment has Fe-Redox of 15.0% or more, which causes it to absorb in the near-infrared region. ２＋ Because the content of this material can be increased, heat is more easily transferred to the molten glass during glass manufacturing, improving manufacturability. In addition, the transmittance in the near-infrared region is reduced, improving heat shielding, making it suitable for applications requiring heat shielding, such as vehicle glass.

[0096] When using the glass of this embodiment for vehicle glass, the Fe-Redox content is more preferably 20.0% or more, even more preferably 22.0% or more, and particularly preferably 24.0% or more. Furthermore, the Fe-Redox content is preferably 50.0% or less. By having an Fe-Redox content of 50.0% or less, deterioration of the dissolution equipment is suppressed, and SO4 is used as a clarifying agent. ３ When this is used, amber coloration can be suppressed and the decrease in visible light transmittance can be kept to a minimum. Fe-Redox is more preferably 45.0% or less, even more preferably 40.0% or less, and particularly preferably 38.0% or less.

[0097] On the other hand, when the glass of this embodiment is used as the cover glass of the LiDAR, Fe-Redox is more preferably 16.0% or more, even more preferably 17.0% or more, and particularly preferably 18.0% or more. Furthermore, Fe-Redox is preferably 35.0% or less. By having Fe-Redox of 35.0% or less, the decrease in transmittance in the near-infrared region can be suppressed. Fe-Redox is more preferably 32.0% or less, even more preferably 30.0% or less, and particularly preferably 28.0% or less.

[0098] Fe-Redox can be adjusted by controlling the raw material composition, melting temperature, and melting atmosphere. Furthermore, Fe-Redox can be adjusted by controlling the oxidation-reduction degree of the glass melt by using reducing agents such as coke and ammonium chloride as raw materials.

[0099] The glass of this embodiment may contain components other than those listed above (hereinafter also referred to as "other components").

[0100] Other components include, for example, TiO ２ , ZrO ２ , Y ２ O ３ , CEO ２ , Nd ２ O ５ GaO ２ , GeO ２ MnO ２ NiO, Cr ２ O ３ , V ２ O ５ Au ２ O ３ Ag ２ O, CuO, CdO, MoO ３ SO ３ Cl, F, SnO ２These include metal ions and oxides. Other components may be included in total at a concentration of 3.0% or less for various purposes (e.g., clarification and coloring, imparting chemical durability, etc.). If the total content of other components is 3.0% or less, the necessary properties for use as cover glass for vehicle glass or sensors such as LiDAR can be maintained. The total content of other components is preferably 2.5% or less, more preferably 2.0% or less, even more preferably 1.5% or less, even more preferably 1.0% or less, particularly preferably 0.80% or less, and most preferably 0.50% or less.

[0101] Furthermore, in order to prevent environmental impact, As ２ O ３ The PbO content is preferably less than 0.0010% for each, and more preferably substantially absent.

[0102] Furthermore, in order to improve chemical durability and the mechanical properties of the glass, the ZnO content is preferably 2.0% or less, more preferably 1.0% or less, even more preferably 0.5% or less, particularly preferably 0.10% or less, and most preferably substantially absent.

[0103] Furthermore, from the viewpoint of suppressing defects during glass molding and from the viewpoint of optical properties, Sb ２ O ３ The content is preferably 2.0% or less, more preferably 1.0% or less, even more preferably 0.5% or less, particularly preferably 0.10% or less, and most preferably substantially absent.

[0104] The glass in this embodiment is ZrO ２ It may include ZrO ２ This is a component that improves chemical durability. The glass of this embodiment is ZrO ２ If it contains ZrO, the content is preferably 0.010% or more, more preferably 0.050% or more, even more preferably 0.10% or more, and particularly preferably 0.20% or more. Also, from the viewpoint of suppressing an increase in the density and viscosity of the glass, ZrO ２ The content is preferably 2.0% or less, more preferably 1.5% or less, even more preferably 1.0% or less, and particularly preferably 0.50% or less.

[0105] The glass in this embodiment is Y ２ O ３ It may include Y. ２ O ３ This is a component that improves Young's modulus. The glass in this embodiment is Y ２ O ３ If it contains, the content is preferably 0.10% or more, more preferably 0.20% or more, even more preferably 0.30% or more, and particularly preferably 0.40% or more. Also, from the viewpoint of suppressing an increase in the density and viscosity of the glass, Y ２ O ３ The content is preferably 2.0% or less, more preferably 1.5% or less, even more preferably 1.0% or less, and particularly preferably 0.80% or less.

[0106] In this embodiment, if NiO is included in the glass, glass fracture may occur due to the formation of NiS; therefore, the NiO content is preferably 0.0080% or less. In the glass of this embodiment, the NiO content is more preferably 0.0040% or less, even more preferably 0.0020% or less, and particularly preferably substantially absent.

[0107] The glass in this embodiment is CeO ２ It may include. CeO ２ Because it absorbs in the ultraviolet region, it reduces the ultraviolet transmittance (Tuv) and improves UV-cutting performance. It also acts as an oxidizing agent and can control Fe-Redox. The glass of this embodiment is CeO ２ If it contains, its content is preferably 0.010% or more, more preferably 0.020% or more, even more preferably 0.040% or more, and particularly preferably 0.070% or more. ２ By absorbing ultraviolet light, solarization may occur, potentially reducing the transmittance in the visible range. Therefore, CeO ２ The content is preferably 0.25% or less, more preferably 0.18% or less, even more preferably 0.14% or less, and particularly preferably 0.10% or less.

[0108] The glass in this embodiment is Cr ２ O ３ It may include Cr. ２ O３ It acts as an oxidizing agent and can control Fe-Redox. The glass in this embodiment is Cr ２ O ３ If it contains, its content is preferably 0.0020% or more, and more preferably 0.0040% or more. Cr ２ O ３ Because it has a coloration to visible light, there is a risk that the visible light transmittance will decrease. Also, Fe ２＋ The amount decreases, and there is a risk that the heat-shielding properties will decline. Therefore, the glass of this embodiment is Cr ２ O ３ If it contains, the content is preferably 0.020% or less, more preferably 0.016% or less, even more preferably 0.012% or less, and particularly preferably 0.0080% or less.

[0109] The glass in this embodiment is SnO ２ It may include SnO ２ It acts as a reducing agent and can control Fe-Redox. The glass in this embodiment is SnO ２ If it contains, its content is preferably 0.010% or more, more preferably 0.040% or more, even more preferably 0.060% or more, and particularly preferably 0.080% or more. On the other hand, when glass is manufactured, SnO ２ To suppress the defects of the origin, the glass of this embodiment contains SnO ２ The content is preferably 0.40% or less, more preferably 0.30% or less, even more preferably 0.20% or less, and particularly preferably 0.15% or less.

[0110] The glass of this embodiment is SO ３ It may include SO. ３ It acts as a fining agent and improves the foam quality of the glass. The glass in this embodiment is SO ３ If it contains, its content is preferably 0.0010% or more, more preferably 0.0040% or more, even more preferably 0.0070% or more, and particularly preferably 0.015% or more. ３ If Fe-Redox is high, amber discoloration may occur, causing the glass to turn brown and potentially reducing visible light transmittance. The glass in this embodiment is SO ３If it contains, its content is preferably 0.070% or less, more preferably 0.060% or less, even more preferably 0.050% or less, and particularly preferably 0.040% or less.

[0111] The glass of this embodiment may contain Cl. Cl acts as a fining agent and improves the foam quality of the glass. When the glass of this embodiment contains Cl, the content is preferably 0.080% or more, more preferably 0.15% or more, even more preferably 0.20% or more, particularly preferably 0.25% or more, and most preferably 0.30% or more. If the Cl content is high, Cl will volatilize from the molten glass. ２ The gas may corrode the surrounding components. If the glass in this embodiment contains Cl, its content is preferably 1.0% or less, more preferably 0.80% or less, even more preferably 0.60% or less, and particularly preferably 0.50% or less.

[0112] [Characteristics] (Fracture toughness value K) ＩＣ The glass of this embodiment has a fracture toughness value K measured by the SEPB method. ＩＣ 0.76 MPa·m １／２ The above is preferable. Fracture toughness value K ＩＣ K is an indicator of glass strength, representing the fracture toughness value. ＩＣ A larger value indicates that cracks are less likely to propagate and that the material has higher resistance to cracking. Therefore, the fracture toughness value K ＩＣ 0.76 MPa·m １／２ The above results in sufficient resistance to cracking, making it suitable for cover glass used in vehicles and sensors. Fracture toughness value K ＩＣ This is 0.78 MPa·m １／２ The above is more preferable, 0.80 MPa·m １／２ The above is even more preferable, 0.82 MPa·m １／２ The above is even more preferable, 0.84 MPa·m １／２ The above is particularly preferable, 0.85 MPa·m １／２ The above is particularly preferred, and is 0.86 MPa·m １／２ The above is particularly preferred, and 0.88 MPa·m １／２ The above is particularly preferred, and is 0.90 MPa·m １／２ The above is particularly preferred, and is 0.91 MPa·m１／２ The above is particularly preferred, and 0.94 MPa·m １／２ The above is the most preferable option.

[0113] Fracture toughness value K ＩＣ This is measured using the Single-Edge-Precracked-Beam method (SEPB method) in accordance with JIS R1607:2015 "Test Method for Room Temperature Fracture Toughness of Fine Ceramics".

[0114] To set the fracture toughness value within the above range, SiO ２ To increase the content of, to increase the proportion of four-coordinate boron, to increase the proportion of alkaline earth metal components with small atomic numbers within RO, R' ２ O or R ２ One method is to increase the proportion of alkali metal components with low atomic numbers within the oxygen atom. Specifically, SiO ２ Ya B ２ O ３ Boron (especially four-coordinate boron) is a component that forms a network structure, so increasing its content strengthens the structure of the glass, thereby improving its fracture toughness. Furthermore, with RO, the smaller the atomic number of the alkaline earth metal component, the higher the Young's modulus of the glass, and as a result, the higher the fracture toughness. ２ O, R ２ For oxygen (O), the lower the atomic number of the alkali metal component, the more similar the trend is to that of red oxide (RO).

[0115] (Young's Modulus) The Young's modulus of the glass in this embodiment is preferably 65 GPa or higher. A Young's modulus of 65 GPa or higher gives the glass high rigidity and improved fracture toughness, making it more suitable for use as window glass for vehicles or cover glass for sensors such as LiDAR. The Young's modulus of the glass in this embodiment is more preferably 68 GPa or higher, even more preferably 70 GPa or higher, even more preferably 72 GPa or higher, particularly preferably 73 GPa or higher, particularly preferably 74 GPa or higher, and most preferably 80 GPa or higher.

[0116] Furthermore, from the viewpoint of suppressing cracking when the glass is subjected to external force, a Young's modulus of 85 GPa or less is preferred, and 83 GPa or less is more preferred. The above Young's modulus may be, for example, 82 GPa or less, 81 GPa or less, or 80 GPa or less.

[0117] To keep the Young's modulus within the above range, increase the proportion of four-coordinate boron, RO, R'. ２ O and R ２ Methods include adjusting the type and amount of oxygen. Young's modulus can be measured by the ultrasonic pulse method based on JIS R1602:1995 "Test method for the elastic modulus of fine ceramics".

[0118] (Rigidity) The rigidity of the glass in this embodiment is preferably 27 GPa or higher. If the rigidity is 27 GPa or higher, the glass is less likely to deform when subjected to external force. The rigidity of the glass is more preferably 28 GPa or higher, even more preferably 29 GPa or higher, particularly preferably 30 GPa or higher, and most preferably 31 GPa or higher.

[0119] Furthermore, since deformation occurs when the glass is subjected to an external force, consuming energy and thus suppressing cracking, the rigidity modulus is preferably 38 GPa or less, more preferably 37 GPa or less, even more preferably 36 GPa or less, and particularly preferably 35 GPa or less. The rigidity modulus can be measured by the ultrasonic pulse method based on JIS R1602:1995 "Test method for the elastic modulus of fine ceramics".

[0120] (Poisson's Ratio) The Poisson's ratio of the glass in this embodiment is preferably 0.26 or less. The smaller the Poisson's ratio, the smaller the stress generated when an external force is applied to the glass. The fracture toughness value also improves. A Poisson's ratio of 0.25 or less is more preferable, 0.24 or less is even more preferable, 0.23 or less is particularly preferable, 0.22 or less is particularly preferable, 0.21 or less is particularly preferable, and 0.20 or less is most preferable. The Poisson's ratio can be measured by the ultrasonic pulse method based on JIS R1602:1995 "Test Method for Elastic Modulus of Fine Ceramics".

[0121] (Surface fracture energy) The surface fracture energy of the glass in this embodiment is 4.50 J / m ２ The above is preferable. A higher surface fracture energy is preferable because it improves the fracture toughness value. The surface fracture energy is 4.60 J / m ２ The above is more preferable, with a load of 4.80 J / m ２ The above is even more preferable, with a load of 4.90 J / m ２ The above is particularly preferred, with a concentration of 5.00 J / m ２ The above is particularly preferred, with a load of 5.30 J / m ２ The above is the most preferable. The surface fracture energy can be determined by measuring the fracture toughness value, Young's modulus, and Poisson's ratio, and calculating it from the relationship in equation (1) above.

[0122] (T ２ In the glass of this embodiment, the glass viscosity η, which serves as the standard for the solubility of the glass, is 10 ２ The temperature T at which [dPa·s] occurs ２ It is preferable that the temperature is 1700°C or lower. ２ By keeping the temperature below 1700°C, the consumption of fuel used during the melting of glass raw materials can be reduced, and the lifespan of the brick components used in the melting furnace can be extended.

[0123] T ２ One method to reduce the temperature to below 1700°C is, for example, the glass component R' ２ O or R ２ Increase the content of O and RO, and Al ２ O ３ Methods to reduce the content, R ２ Among O, Li ２ Methods for incorporating O, SiO ２ Methods to reduce the content, B ２ O ３ One method is to adjust the content of [the substance]. ２ The temperature is more preferably 1675°C or lower, even more preferably 1650°C or lower, even more preferably 1640°C or lower, particularly preferably 1630°C or lower, and most preferably 1620°C or lower. Furthermore, from the viewpoint of maintaining the fracture toughness of the glass and suppressing the average coefficient of linear expansion of the glass from becoming too large, ２A temperature of 1450°C or higher is preferred, 1475°C or higher is more preferred, 1500°C or higher is even more preferred, 1525°C or higher is particularly preferred, and 1550°C or higher is most preferred.

[0124] (T ４ In the glass of this embodiment, the glass viscosity η, which serves as the standard for moldability during float molding, is 10 ４ The temperature T at which [dPa·s] occurs ４ It is preferable that the temperature is 1200°C or lower. ４ Since the temperature is below 1200°C, it is suitable for sheet metal forming using the float method.

[0125] T ４ One method to reduce the temperature to below 1200°C is, for example, the R' of the glass component. ２ O, R ２ Increase the content of O and RO, Al ２ O ３ Methods to reduce the content, R ２ Among O, Li ２ Methods for incorporating O, SiO ２ Methods to reduce the content, B ２ O ３ One method is to adjust the content of [the substance].

[0126] T ４ A temperature of 1180°C or lower is more preferable, 1170°C or lower is even more preferable, 1160°C or lower is even more preferable, 1150°C or lower is particularly preferable, and 1140°C or lower is most preferable. Furthermore, from the viewpoint of maintaining the fracture toughness of the glass and suppressing the average coefficient of linear expansion of the glass from becoming too large, ４ The temperature is preferably 1000°C or higher, more preferably 1025°C or higher, even more preferably 1050°C or higher, and particularly preferably 1070°C or higher.

[0127] (T １１ In the glass of this embodiment, the glass viscosity η, which serves as the standard for bendability, is 10 １１ The temperature T at which [dPa·s] occurs １１ It is preferable that the temperature is 640°C or lower. １１ Because the temperature is below 640°C, bending and forming can be performed at low temperatures.

[0128] T １１ One method to keep the temperature below 640°C is, for example, to change the R' of the glass component. ２ O, R ２ Increase the content of O and RO, Al ２ O ３ Methods to reduce the content, R ２ Among O, Li ２ Methods for incorporating O, SiO ２ Methods to reduce the content, B ２ O ３ This includes adjusting the content and coordination number of boron.

[0129] In the glass of this embodiment, T １１ A temperature of 635°C or lower is more preferable, 630°C or lower is even more preferable, 625°C or lower is even more preferable, 620°C or lower is particularly preferable, 615°C or lower is especially preferable, and 610°C or lower is most preferable.

[0130] Furthermore, from the standpoint of maintaining the fracture toughness of the glass, suppressing the average coefficient of thermal expansion of the glass from becoming too large, and from the standpoint of keeping the firing temperature of the black ceramic printed on the windshield within an appropriate range, T １１ The temperature is preferably 570°C or higher, more preferably 575°C or higher, even more preferably 580°C or higher, particularly preferably 585°C or higher, and most preferably 590°C or higher.

[0131] (T １２ In the glass of this embodiment, the glass viscosity η, which serves as the standard for bendability, is 10 １２ The temperature T at which [dPa·s] occurs １２ It is preferable that the temperature is 610°C or lower. １２ Because the temperature is below 610°C, bending and forming can be performed at low temperatures.

[0132] T １２ One method to keep the temperature below 610°C is, for example, to change the R' of the glass component. ２ O, R ２ Increase the content of O and RO, Al ２ O ３ Methods to reduce the content, R ２ Among O, Li ２ Methods for incorporating O, SiO２ Methods to reduce the content, B ２ O ３ Methods for adjusting the content and coordination number of boron are mentioned.

[0133] T １２ The temperature is more preferably 605°C or lower, even more preferably 600°C or lower, even more preferably 595°C or lower, especially preferably 590°C or lower, particularly preferably 585°C or lower, and most preferably 580°C or lower. Furthermore, from the viewpoint of maintaining the fracture toughness of the glass, suppressing the average coefficient of linear expansion of the glass from becoming too large, and setting the firing temperature of the black ceramic printed on the windshield within an appropriate range, １２ The temperature is preferably 540°C or higher, more preferably 545°C or higher, even more preferably 550°C or higher, particularly preferably 555°C or higher, and most preferably 560°C or higher.

[0134] (Density) The density of the glass in this embodiment is 2.50 g / cm³. ３ Preferably, the density is 2.50 g / cm³. ３ The following conditions make it possible to suppress the increase in fuel consumption and electricity consumption associated with increased weight. Generally, glass with high Young's modulus and fracture toughness values ​​tends to have high density, but the glass of this embodiment has a high R' of the glass component. ２ O, R ２ The composition and content of O and RO and B ２ O ３ By adjusting the content and the coordination number of boron, it is possible to achieve a low density while simultaneously achieving a high Young's modulus and fracture toughness.

[0135] The density of the glass in this embodiment is 2.46 g / cm³. ３ The following is more preferable: 2.44 g / cm³ ３ The following is even more preferable: 2.42 g / cm³ ３ The following is even more preferable: 2.40 g / cm³ ３ The following is particularly preferred: 2.38 g / cm³ ３ The following is particularly preferred: 2.36 g / cm³ ３ The following is most preferable. Furthermore, the density of the glass in this embodiment is 2.25 g / cm³ from the viewpoint of improving sound insulation. ３The above is preferable, and 2.27 g / cm³ ３ The above is more preferable, specifically 2.28 g / cm³. ３ The above is particularly preferred, at 2.29 g / cm³. ３ The above is the most preferable option.

[0136] (T ｇ ) The glass transition temperature (T) of the glass in this embodiment ｇ The temperature is preferably in the range of 460 to 590°C. ｇ If the temperature is within this predetermined range, the glass can be bent under normal manufacturing conditions. ｇ By keeping the temperature above 460°C, the alkali metal content or alkaline earth metal content does not become excessively high, thus suppressing an increase in the average coefficient of thermal expansion of the glass. Furthermore, it suppresses moisture resistance and devitrification of the glass, improving moldability. ｇ More preferably 480°C or higher, even more preferably 490°C or higher, and particularly preferably 500°C or higher. Furthermore, from the viewpoint of suppressing excessive bending temperatures of the glass and facilitating manufacturing, T ｇ The temperature is preferably 590°C or lower, more preferably 585°C or lower, even more preferably 580°C or lower, particularly preferably 575°C or lower, and most preferably 570°C or lower.

[0137] (Average coefficient of linear thermal expansion) The average coefficient of linear thermal expansion (CTE) of the glass in this embodiment at 50 to 350°C is 80 × 10 －７ It is preferable that the temperature is below / °C. The average coefficient of linear thermal expansion is 80 × 10⁻⁶. －７ By maintaining a temperature below / °C, cracking due to thermal shock can be suppressed when used as glass for vehicles or sensors. Furthermore, when the glass of this embodiment is bent, the difference in thermal expansion due to differences in the thermal history within the plane is suppressed, resulting in bent glass with good dimensional and surface accuracy.

[0138] The average coefficient of linear thermal expansion of the glass in this embodiment at 50 to 350°C is 75 × 10⁻⁶. －７ / ℃ or lower is more preferable, 70 × 10 －７ A temperature of 68 × 10°C or lower is even more preferable. －７ More preferably below / ℃, 66 × 10 －７A temperature of 64 × 10°C or lower is particularly preferred. －７ A temperature of / ℃ or lower is most preferable.

[0139] Furthermore, the glass of this embodiment has an average linear expansion coefficient of 40 × 10⁻¹⁰, from the viewpoint of suppressing cracking of the black ceramic due to the difference in thermal expansion with the black ceramic printed on the windshield. －７ It is preferable that the temperature is above / ℃. The average coefficient of linear thermal expansion is 40 × 10 －７ By maintaining a temperature above 10°C, the difference in thermal expansion with the black ceramic is reduced, which suppresses cracking of the black ceramic. The average coefficient of linear expansion is 42 × 10°C. －７ More preferably above / ℃, 44 × 10 －７ A temperature of 46 × 10°C or higher is even more preferable. －７ A temperature of 1 / ℃ or higher is particularly preferred, 48 × 10 －７ A temperature of 1 / ℃ or higher is particularly preferred, and 50 × 10 －７ A temperature of 1 / °C or higher is particularly preferred, and 52 × 10 －７ A temperature of / ℃ or higher is most preferable.

[0140] To keep the average coefficient of linear thermal expansion within the above range, the SiO content of the glass component must be... ２ Increase the content of R ２ O or R' ２ O, RO, and Al ２ O ３ Content of B ２ O ３ Methods for adjusting the content and coordination number of boron are mentioned.

[0141] (Solar transmittance: Te) When the glass of this embodiment is used for vehicle glass, it is preferable that the solar transmittance Te of the glass of this embodiment, when converted to a thickness of 2.0 mm, is 90% or less as specified in ISO-9050:2003. Excellent heat shielding properties can be obtained if Te is 90% or less. Te is preferably 88% or less, more preferably 86% or less, even more preferably 84% or less, particularly preferably 82% or less, and most preferably 80% or less. The lower limit of Te is not particularly limited, but is usually 30% or more, preferably 32% or more, more preferably 34% or more, and particularly preferably 36% or more.

[0142] To set Te to the above range, Fe ２ O３ This can be achieved by adjusting the quantity to 0.030% or higher.

[0143] (Visible light transmittance: Tv) When the glass of this embodiment is used for vehicle glass, it is preferable that the visible light transmittance Tv of the glass of this embodiment, calculated by measuring the transmittance using a spectrophotometer with a D65 light source in accordance with the provisions of ISO-9050:2003, when the thickness is converted to 2.00 mm, is 75% or more. Because Tv is 75% or more, it has excellent transparency and is therefore more suitable for vehicle glass, especially windshields and door glass. Tv is more preferably 78% or more, even more preferably 80% or more, and even more preferably 82% or more. Tv is particularly preferably 84% or more, and most preferably 86% or more. There is no particular upper limit to Tv, but for example it is 92% or less.

[0144] To set Tv within the above range, the glass composition, especially SiO ２ ya Fe ２ O ３ The content and B ２ O ３ This can be achieved by adjusting the content and coordination number of boron.

[0145] (Ultraviolet Transmittance: Tuv) When the glass of this embodiment is used for vehicle glass, it is preferable that the glass of this embodiment has low ultraviolet transmittance, and when converted to a thickness of 2.00 mm, the ultraviolet transmittance Tuv as defined in ISO-9050:2003 is preferably 70% or less. By having a Tuv of 70% or less, deterioration of materials such as interlayers and seats inside the vehicle can be suppressed when the glass of this embodiment is used in laminated glass. A Tuv of 68% or less is more preferable, 66% or less is even more preferable, 64% or less is even more preferable, 62% or less is particularly preferable, and 60% or less is most preferable. The lower limit of Tuv is, for example, 10% or more.

[0146] To set Tuv within the above range, the glass composition, especially SiO ２ ya Fe ２ O ３ , TiO ２ or CEO ２This can be achieved by adjusting the content of or Fe-Redox.

[0147] (Dominant wavelength: Dw) When using the glass of this embodiment for vehicle glass, it is preferable that the dominant wavelength Dw of the glass of this embodiment, as measured using a standard C light source specified in JIS Z 8701:1999, is 520 nm or more and 574 nm or less. More preferably, Dw is 525 nm or more, even more preferably 530 nm or more, particularly preferably 535 nm or more, and most preferably 540 nm or more. Furthermore, it is more preferable that Dw be 573 nm or less, even more preferably 570 nm or less, particularly preferably 567 nm or less, and most preferably 565 nm or less.

[0148] (Irritation purity: Pe) When using the glass of this embodiment for vehicle glass, it is preferable that the irritation purity Pe of the glass of this embodiment, measured using a standard C light source specified in JIS Z 8701:1999, is 4.0% or less. More preferably, Pe is 3.5% or less, even more preferably 3.0% or less, even more preferably 2.5% or less, particularly preferably 2.0% or less, and most preferably 1.5% or less. The lower limit of Pe is not particularly limited, but is generally 0.1% or more. When Dw and Pe are within the above ranges, the glass becomes gray in color and exhibits excellent design properties.

[0149] To adjust Dw and Pe, Fe is added to the glass of this embodiment. ２ O ３ It can be produced by adjusting the ratio of three-coordinate boron to four-coordinate boron while incorporating the necessary components.

[0150] When using the glass of this embodiment for vehicle windows, the shape of the glass of this embodiment is not particularly limited, but the area of ​​the main surface is 0.25 m². ２ The above is preferable, and 0.45 m ２ The above is more preferable, 0.90 m ２ The above is even more preferable. When the glass area is within the above range, it can be used for various car models. Also, if the glass area is too large, it becomes difficult to handle, the temperature distribution during heating becomes uneven, and the dimensional accuracy after bending becomes poor, thus increasing the difficulty of bending. For this reason, the glass of this embodiment has a main surface area of ​​10 m². ２The following is preferable: 7m ２ The following is more preferable: 5m ２ The following are even more preferable.

[0151] When using the glass of this embodiment as the cover glass for a LiDAR, it is preferable that the glass of this embodiment has high transmittance at wavelengths of 905 nm and 1550 nm, which are used in LiDAR. Therefore, when the glass of this embodiment is converted to a thickness of 4.0 mm, the transmittance at wavelengths of 905 nm or 1550 nm is preferably 86% or higher, more preferably 87% or higher, even more preferably 88% or higher, even more preferably 89% or higher, particularly preferably 90% or higher, and most preferably 91% or higher.

[0152] When the glass of this embodiment is used as a cover glass for a sensor, the shape of the glass of this embodiment is not particularly limited, but the area of ​​the main surface is 0.00010 m². ２ The above is preferable, and 0.010 m ２ The above is more preferable, 0.020 m ２ The above is even more preferable, 0.040 m ２ The above is particularly preferred, 0.090 m ２ The above is the most preferable. When the glass area is within the above range, it can accommodate various LiDAR cover glass types. Furthermore, if the glass area is too large, the temperature distribution during heating becomes uneven, and the dimensional accuracy after bending becomes poor, increasing the difficulty of bending. Therefore, the glass in this embodiment has a main surface area of ​​1.0 m². ２ The following is preferred: 0.90 m ２ The following is more preferable: 0.80 m ２ The following are even more preferable.

[0153] Furthermore, the glass of this embodiment preferably has a surface roughness Ra of 5.0 nm or less, a thickness of 2.5 mm, and a critical impact fracture velocity of 35 km / h or more when struck by a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g. A critical impact fracture velocity of 35 km / h or more improves resistance to flying stones. A critical impact fracture velocity of 40 km / h or more is more preferable, 45 km / h or more is even more preferable, 50 km / h or more is particularly preferable, and 55 km / h or more is most preferable. The upper limit of the critical impact fracture velocity is, for example, 120 km / h or less. The surface roughness Ra can be measured according to JIS B0601:2001.

[0154] Furthermore, the glass of this embodiment preferably has a critical impact fracture velocity of 55 km / h or higher when a tungsten carbide cemented carbide alloy with a tip curvature radius of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted against the glass. A critical impact fracture velocity of 55 km / h or higher further improves resistance to flying debris. A critical impact fracture velocity of 57 km / h or higher is more preferable, 60 km / h or higher is even more preferable, 62 km / h or higher is even more preferable, 64 km / h or higher is particularly preferable, 66 km / h or higher is particularly preferable, 68 km / h or higher is particularly preferable, and 70 km / h or higher is most preferable. The upper limit of the critical impact fracture velocity is, for example, 120 km / h or lower. The critical impact fracture velocity can be measured by the method described in the embodiments below.

[0155] The glass of this embodiment is preferably 2.5 mm or thicker. In particular, when the glass of this embodiment has the above-mentioned properties, the thickness of the glass is preferably 2.5 mm or thicker. By having a glass thickness of 2.5 mm or thicker, the critical impact fracture rate of glass with high fracture toughness can be improved. The thickness of the glass is more preferably 2.8 mm or thicker, even more preferably 2.9 mm or thicker, even more preferably 3.0 mm or thicker, especially preferably 3.1 mm or thicker, even more preferably 3.2 mm or thicker, even more preferably 3.3 mm or thicker, particularly preferably 3.4 mm or thicker, and most preferably 3.5 mm or thicker.

[0156] Furthermore, from the viewpoint of suppressing the increase in fuel consumption and electricity consumption due to the increase in weight of the glass, the thickness of the glass in this embodiment is preferably 5.0 mm or less, more preferably 4.8 mm or less, even more preferably 4.5 mm or less, particularly preferably 4.2 mm or less, and most preferably 4.0 mm or less. Methods for adjusting the thickness of the glass include adjusting the thickness of the glass using the float method or downdraw method described later, or polishing the glass in the thickness direction using a grinding wheel and then using an abrasive such as cerium oxide to make it mirror-like. The surface roughness Ra after molding or polishing is preferably 5.0 nm or less, more preferably 2.0 nm or less, even more preferably 1.5 nm or less, particularly preferably 1.0 nm or less, and most preferably 0.50 nm or less.

[0157] The glass of this embodiment is obtained, for example, by melting glass raw materials, shaping the molten glass, and cooling it. At this time, the ratio of three-coordinate boron to four-coordinate boron can be adjusted by adjusting the average cooling rate of the glass. Here, the average cooling rate is the average cooling rate when the shaped glass is slowly cooled. A slower average cooling rate results in a lower three-coordinate boron content, thus improving fracture toughness. Specifically, the cooling rate is preferably 400°C / min or less, more preferably 300°C / min or less, even more preferably 250°C / min or less, even more preferably 200°C / min or less, particularly preferably 150°C / min or less, and most preferably 100°C / min or less.

[0158] The average cooling rate can be calculated as follows: Analyze the composition of the glass for which you want to calculate the average cooling rate, and then produce multiple samples of the same composition at different average cooling rates. Measure the refractive index of the produced samples and create a calibration curve between the average cooling rate and the refractive index. By determining the refractive index of the glass for which you want to calculate the average cooling rate, you can calculate the average cooling rate from the calibration curve. The refractive index can be measured, for example, by the V-block method.

[0159] Furthermore, the glass in this embodiment is preferably float glass formed by, for example, the known float method. In the float method, molten glass material is floated on a molten metal such as tin, and glass with uniform thickness and width can be formed by precise temperature control, as well as large-area glass.

[0160] Furthermore, the glass in this embodiment may be glass formed by known roll-out or down-draw methods, and may be glass with a polished surface and uniform thickness. The down-draw method is broadly classified into slot down-draw and overflow down-draw (fusion) methods, but both are methods in which molten glass is continuously flowed down from a molded body to form a strip-shaped glass ribbon.

[0161] The glass in this embodiment may be glass that has undergone strengthening treatment by air cooling or chemical strengthening. The strength of the glass can be increased by performing the above treatments.

[0162] Here, air-cooled strengthening is a process that forms a compressive stress layer on the surface of glass through thermal strengthening. Specifically, uniformly heated glass is rapidly cooled from a temperature near its softening point, and compressive stress is formed on the glass surface due to the temperature difference between the surface and the interior. The compressive stress is generated uniformly across the entire surface of the glass, forming a compressive stress layer of uniform depth across the entire surface of the glass. Thermal strengthening is more suitable for strengthening thicker glass sheets than chemical strengthening.

[0163] Chemical strengthening is a process that forms a compressive stress layer on the surface of glass by exchanging alkali metal ions with small ionic radii (typically Li ions or Na ions) on the glass surface with alkali metal ions with larger ionic radii (typically Na ions or K ions) at a temperature below the glass transition temperature. Chemical strengthening can be carried out by known methods, such as the ion exchange method. In the ion exchange method, a glass plate is immersed in a treatment solution (e.g., molten potassium nitrate), and compressive stress is generated on the surface of the glass by exchanging ions with small ionic radii (e.g., Na ions) contained in the glass with ions with large ionic radii (e.g., K ions).

[0164] The magnitude of the compressive stress on the glass surface (hereinafter also referred to as surface compressive stress CS) and the depth DOL of the compressive stress layer formed on the glass surface can be adjusted by the glass composition, chemical strengthening treatment time, and chemical strengthening treatment temperature, respectively.

[0165] [Bent Glass] The bent glass according to this embodiment is made of the above-described glass. That is, it is formed by bending the glass of this embodiment. The bent glass according to this embodiment may be bent glass formed from a flat plate-shaped glass of this embodiment into a curved shape by gravity forming or press forming or the like.

[0166] The curved glass of this embodiment is glass that curves with a predetermined curvature, and may be single-curved glass that curves in only one direction, either vertically or horizontally, or double-curved glass that curves in both vertically or horizontally.

[0167] In this embodiment, the curved glass preferably has a minimum radius of curvature of 50 mm or more and 100,000 mm or less. The radius of curvature of the curved glass is determined as follows: The sample is subjected to a laser displacement meter (Dyvoce manufactured by Kozu Seiki Co., Ltd.), and the radius of curvature is calculated from the shape obtained by the shape obtained from the simulation, based on the amount of warping inherent in the sample, which is determined by self-weight deflection correction using the double-sided difference mode.

[0168] [Method for Manufacturing Bent Glass] In the method for manufacturing bent glass according to this embodiment, bent glass is formed by heating and bending the glass. One method for forming bent glass is to heat a flat-shaped piece of glass, place it on a mold, and press it from above with a pressing device to form it into a curved shape. Another method is to place a flat-shaped piece of glass on a mold having a bending surface that corresponds to a desired curved surface, then transport the mold into a heating furnace and heat the glass in the furnace to near its glass softening point. With this forming method, the glass bends along the bending surface of the mold due to its own weight as it softens, thus producing bent glass with a desired curved surface.

[0169] In this embodiment, bending by the above-described press means is preferred from the viewpoint of improving productivity and surface accuracy after molding. The bending method by the above-described press means is not particularly limited, and methods such as those described in International Publication No. 2016 / 093031 can be appropriately adopted. The bending method by the above-described press means will be described exemplified below.

[0170] First, the glass of this embodiment is transported to the press area by a conveyor belt or the like. Next, in the press area, the glass is heated to a temperature at which it can be bent and softened. Here, the temperature at which it can be bent and softened is, for example, when the glass viscosity is 10 １２ The temperature T at which [dPa·s] occurs １２ That concludes the explanation. Note that the heating may also be performed using a heater in a heating furnace during the process of transporting the material to the press area via a conveyor belt, etc. Furthermore, the heating temperature (≧T) １２ The bending time under conditions that maintain the above can be set to, for example, 1 second or more.

[0171] A lower press die (female die) and an upper press die (male die) are positioned in predetermined locations within the press area. The shape of the upper surface of the female die and the lower surface of the male die correspond to the curved shape of the glass to be bent in the direction of transport or perpendicular to it. The female die can move up and down between a waiting position below the transport conveyor and a pressing position above it. After the glass is transferred from the transport conveyor, the female die, with the glass still in place, rises from a predetermined raised position to the pressing position above the transport conveyor, thereby press-forming the glass.

[0172] Next, the press-formed glass is transported to the cooling area by a transport shuttle or similar means. In the cooling area, the glass is cooled by blowing cooling air onto it.

[0173] The bent glass is formed through the above process. Although the bending of the glass in this embodiment has been described above, the bending may also be performed in the state of laminated glass, as will be described later.

[0174] [Laminated Glass] The laminated glass according to this embodiment comprises a first glass plate, a second glass plate, and an interlayer sandwiched between the first glass plate and the second glass plate, wherein the first glass plate is the glass of this embodiment or the bent glass of this embodiment.

[0175] Figure 5 shows an example of laminated glass 10 according to this embodiment. The laminated glass 10 comprises a first glass plate 11, a second glass plate 12, and an interlayer 13 sandwiched between the first glass plate 11 and the second glass plate 12. Note that the laminated glass 10 according to this embodiment is not limited to the configuration shown in Figure 5, and can be modified without departing from the spirit of this embodiment. For example, the interlayer 13 may be formed as a single layer as shown in Figure 5, or it may be formed as two or more layers. Also, the laminated glass 10 according to this embodiment may have three or more glass plates, in which case an organic resin or the like may be interposed between adjacent glass plates. Hereinafter, the laminated glass 10 according to this embodiment will be described as having only two glass plates, the first glass plate 11 and the second glass plate 12, with the interlayer 13 sandwiched between them.

[0176] In the laminated glass of this embodiment, from the viewpoint of bendability, the second glass plate 12 is preferably the glass of this embodiment or the bendable glass of this embodiment. When the first glass plate 11 and the second glass plate 12 are the glass of this embodiment or the bendable glass of this embodiment, the first glass plate 11 and the second glass plate 12 may be glass plates of the same composition or glass plates of different compositions.

[0177] If the second glass plate 12 is not the glass of this embodiment, the type of glass plate is not particularly limited, and conventionally known glass plates used for vehicle windows and the like can be used. Specifically, examples include alkali aluminosilicate glass, alkali aluminoborosilicate glass, and soda-lime glass. These glass plates may or may not be colored, as long as their transparency is not impaired.

[0178] Furthermore, in this embodiment, the second glass plate 12 is made of Al ２ O ３Alkali aluminosilicate glass containing 1.0% or more of Al ２ O ３ Contains 1.0% or more of B ２ O ３ Alkali aluminoborosilicate glass containing 1.0% or more of the above-mentioned material may also be used. By making the second glass plate 12 the above-mentioned alkali aluminosilicate glass or alkali aluminoborosilicate glass, chemical strengthening becomes possible as described later, and the strength can be increased.

[0179] The above alkali aluminosilicate glass and alkali aluminoborosilicate glass are Al from the viewpoint of improving weather resistance, moisture resistance and chemical strengthening properties. ２ O ３ The content of is more preferably 5.0% or more, even more preferably 8.0% or more, and particularly preferably 10% or more. In addition, from the viewpoint of reducing the viscosity of the glass and facilitating manufacturing, Al ２ O ３ The content is preferably 18% or less, and more preferably 15% or less.

[0180] The above alkali aluminosilicate glass and alkali aluminoborosilicate glass are, from the viewpoint of chemical strengthening, R ２ The O content is preferably 10% or more, more preferably 12% or more, and even more preferably 13% or more. Also, from the viewpoint of improving moisture resistance, R ２ The O content is preferably 22% or less, more preferably 20% or less, and even more preferably 18% or less.

[0181] The above alkali aluminoborosilicate glass is designed to increase strength when flying stones, vehicle keys, etc. come into contact with the glass, and is B ２ O ３ The content of is preferably 2.0% or more, more preferably 3.0% or more, and even more preferably 4.0% or more. In addition, in alkali aluminoborosilicate glass, from the viewpoint of improving chemical durability and weather resistance, B ２ O ３ The content is preferably 9.0% or less, more preferably 8.0% or less, and even more preferably 7.0% or less.

[0182] The alkali aluminosilicate glass mentioned above can be exemplified by the following composition. Each component is expressed in mole percentage based on oxide. 61% ≤ SiO ２ ≤75% 1.0% ≤Al ２ O ３ ≤20% 0.0%≦MgO≦15% 0.0%≦CaO≦10% 0.0%≦SrO≦1.0% 0.0%≦BaO≦1.0% 0.0%≦Li ２ O ≤ 15% 2.0% ≤ Na ２ O ≤ 15% 0.0% ≤ K ２ O ≤ 6.0% 0.0% ≤ ZrO ２ ≤4.0% 0.0% ≤TiO ２ ≤1.0% 0.0% ≤Y ２ O ３ ≤2.0% 10% ≤R ２ O≦25% 0.0%≦RO≦20% (R ２ O is Li ２ O, Na ２ O and K ２ RO represents the total content of O, MgO, CaO, SrO, and BaO.

[0183] The alkali aluminoborosilicate glass described above can be exemplified by the following composition. Each component is expressed in mole percentage based on oxide. 61% ≤ SiO ２ ≤75% 1.0% ≤Al ２ O ３ ≤20% 1.0% ≤B ２ O ３ ≤10% 0.0%≦MgO≦15% 0.0%≦CaO≦10% 0.0%≦SrO≦1.0% 0.0%≦BaO≦1.0% 0.0%≦Li ２ O ≤ 15% 2.0% ≤ Na ２ O ≤ 15% 0.0% ≤ K ２ O ≤ 6.0% 0.0% ≤ ZrO ２ ≤4.0% 0.0% ≤TiO ２ ≤1.0% 0.0% ≤Y ２ O ３ ≤2.0% 10% ≤R ２ O≦25% 0.0%≦RO≦20% (R２ O is Li ２ O, Na ２ O and K ２ RO represents the total content of O, MgO, CaO, SrO, and BaO.

[0184] Furthermore, in the laminated glass of this embodiment, the second glass plate 12 may be soda-lime glass. As for soda-lime glass, Al ２ O ３ Soda-lime glass containing 3.5% or less, preferably less than 1.0%, is also acceptable. Specifically, the following glass compositions are examples. Each component is expressed in molar percentage based on oxide. 60% ≤ SiO ２ ≤75% 0.0% ≤Al ２ O ３ ≤3.5% 2.0%≦MgO≦11% 2.0%≦CaO≦10% 0.0%≦SrO≦3.0% 0.0%≦BaO≦3.0% 10%≦Na ２ O ≤ 18% 0.0% ≤ K ２ O ≤ 8.0% 0.0% ≤ ZrO ２ ≤4.0% 0.0010% ≤Fe ２ O ３ ≤ 5.0%

[0185] The thickness of the first glass plate 11 is preferably 2.5 mm or more. A thickness of 2.5 mm or more for the first glass plate 11 can improve the critical impact fracture rate of glass with high fracture toughness. The thickness of the first glass plate 11 is more preferably 2.8 mm or more, even more preferably 2.9 mm or more, even more preferably 3.0 mm or more, especially preferably 3.1 mm or more, even more preferably 3.2 mm or more, even more preferably 3.3 mm or more, particularly preferably 3.4 mm or more, and most preferably 3.5 mm or more.

[0186] Furthermore, from the viewpoint of suppressing the increase in fuel consumption and electricity consumption due to the increase in weight of the glass, the thickness of the first glass plate 11 is preferably 5.0 mm or less, more preferably 4.8 mm or less, even more preferably 4.5 mm or less, particularly preferably 4.2 mm or less, and most preferably 4.0 mm or less.

[0187] The thickness of the second glass plate 12 is preferably 0.50 mm or more, more preferably 0.60 mm or more, even more preferably 0.70 mm or more, particularly preferably 0.80 mm or more, particularly preferably 0.90 mm or more, and most preferably 1.0 mm or more. A thickness of 0.50 mm or more for the second glass plate 12 is preferable from the viewpoint of impact resistance.

[0188] Furthermore, the thickness of the second glass plate 12 is preferably 2.0 mm or less, more preferably 1.9 mm or less, even more preferably 1.8 mm or less, particularly preferably 1.7 mm or less, particularly preferably 1.6 mm or less, and most preferably 1.5 mm or less. When the thickness of the second glass plate 12 is 2.0 mm or less, the weight of the laminated glass 10 does not become too large, which is preferable in terms of improving fuel efficiency when used in a vehicle.

[0189] Furthermore, the thicknesses of the first glass plate 11 and the second glass plate 12 may be the same or different, but it is preferable that the first glass plate 11 is thicker than the second glass plate 12. Methods for adjusting the thickness of the first glass plate 11 and the second glass plate 12 include adjusting the thickness of the glass using the float method or the down-draw method, or polishing the glass in the thickness direction using a grinding wheel and then using an abrasive such as cerium oxide to achieve a mirror finish. The surface roughness Ra after molding or polishing is preferably 5.0 nm or less, more preferably 2.0 nm or less, even more preferably 1.5 nm or less, particularly preferably 1.0 nm or less, and most preferably 0.50 nm or less.

[0190] In this embodiment, the thickness of the first glass plate 11 and the second glass plate 12 of the laminated glass 10 may be constant throughout the entire surface, or it may vary from place to place as needed, such as forming a wedge shape in which the thickness of one or both of the first glass plate 11 and the second glass plate 12 gradually decreases.

[0191] At least one of the first glass plate 11 and the second glass plate 12 may be chemically strengthened glass that has undergone chemical strengthening treatment to improve its strength. The method of chemical strengthening treatment is the same as that for chemical strengthening glass described above. Examples of chemically strengthened glass include the alkali aluminosilicate glass and alkali aluminoborosilicate glass that have undergone chemical strengthening treatment.

[0192] The shape of the first glass plate 11 and the second glass plate 12 may be flat, or it may be a curved shape with curvature in all or part of its surface. If the first glass plate 11 and the second glass plate 12 are curved, they may be a single-bend shape curving in only one direction, either vertically or horizontally, or a double-bend shape curving in both vertically or horizontally. If the first glass plate 11 and the second glass plate 12 are double-bend shapes, the radii of curvature in the vertical and horizontal directions may be the same or different. If the first glass plate 11 and the second glass plate 12 are curved, the radii of curvature in the vertical and / or horizontal directions are preferably 1000 mm or more. The shape of the main surface of the first glass plate 11 and the second glass plate 12 is such that it fits the window opening of the vehicle in which it is installed.

[0193] The interlayer 13 is sandwiched between the first glass plate 11 and the second glass plate 12. In this embodiment, the laminated glass 10, by including the interlayer 13, firmly bonds the first glass plate 11 and the second glass plate 12 and can mitigate the impact force when scattered fragments collide with the glass plate.

[0194] As the interlayer 13, various organic resins commonly used in laminated glass for conventional vehicles can be used. Examples of organic resins include polyethylene (PE), ethylene vinyl acetate copolymer (EVA), polypropylene (PP), polystyrene (PS), methacrylic resin (PMA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cellulose acetate (CA), diallyl phthalate resin (DAP), urea resin (UP), melamine resin (MF), unsaturated polyester (UP), polyvinyl butyral (PVB), and polyvinyl phosphate. Materials such as maar (PVF), polyvinyl alcohol (PVAL), vinyl acetate resin (PVAc), ionomer (IO), polymethylpentene (TPX), vinylidene chloride (PVDC), polysulfone (PSF), polyvinylidene fluoride (PVDF), methacrylic-styrene copolymer resin (MS), polyalate (PAR), polyallyl sulfone (PASF), polybutadiene (BR), polyethersulfone (PESF), or polyetheretherketone (PEEK) can be used. Among these, EVA and PVB are preferred from the viewpoint of transparency and adhesion, and PVB is particularly preferred because it can provide sound insulation.

[0195] The thickness of the interlayer 13 is preferably 0.300 mm or more, more preferably 0.500 mm or more, and even more preferably 0.700 mm or more, from the viewpoint of impact force mitigation and sound insulation. Furthermore, the thickness of the interlayer 13 is preferably 1.00 mm or less, more preferably 0.900 mm or less, and even more preferably 0.800 mm or less, from the viewpoint of suppressing a decrease in visible light transmittance. Furthermore, the thickness of the interlayer 13 is preferably in the range of 0.300 mm to 1.00 mm, and more preferably in the range of 0.700 mm to 0.800 mm.

[0196] The interlayer 13 may have a uniform thickness across the entire surface, or its thickness may vary from place to place as needed.

[0197] Furthermore, if the difference in the coefficient of linear expansion between the interlayer 13 and the first glass plate 11 or the second glass plate 12 is large, cracks or warping may occur in the laminated glass 10 when it is manufactured through the heating process described later, potentially leading to a defective appearance. Therefore, it is preferable that the difference between the coefficient of linear expansion between the interlayer 13 and the first glass plate 11 or the second glass plate 12 be as small as possible. The difference between the coefficient of linear expansion between the interlayer 13 and the first glass plate 11 or the second glass plate 12 may be expressed as the difference between the average coefficients of linear expansion over a predetermined temperature range.

[0198] In particular, since the resin constituting the interlayer 13 has a low glass transition temperature, a predetermined average difference in linear thermal expansion coefficients may be set within a temperature range below the glass transition temperature of the resin material. The difference in linear thermal expansion coefficients between the first glass plate 11 or the second glass plate 12 and the resin material may be set at a predetermined temperature below the glass transition temperature of the resin material.

[0199] Furthermore, the interlayer 13 may be an adhesive layer containing an adhesive, and the adhesive is not particularly limited, but for example, an acrylic adhesive or a silicone adhesive can be used. When the interlayer 13 is an adhesive layer, there is no need to go through a heating process in the joining process between the first glass plate 11 and the second glass plate 12, so there is less risk of the above-mentioned cracking or warping occurring.

[0200] [Other Layers] The laminated glass 10 of this embodiment may include layers other than the first glass plate 11, the second glass plate 12, and the interlayer 13 (hereinafter also referred to as "other layers"), to the extent that they do not impair the effects of this embodiment. For example, it may include a coating layer that provides water-repellent, hydrophilic, or anti-fogging functions, or an infrared reflective film.

[0201] The location of the other layers is not particularly limited and may be provided on the surface of the laminated glass 10, or it may be provided so as to be sandwiched between the first glass plate 11, the second glass plate 12, or the interlayer 13. Furthermore, the laminated glass 10 of this embodiment may include a black ceramic layer or the like, which is arranged in a strip shape on part or all of the peripheral edge for the purpose of concealing attachment parts to a frame or wiring conductors.

[0202] In this embodiment, the laminated glass 10 preferably has a first glass plate 11 with a surface roughness Ra of 5.0 nm or less and a thickness of 2.5 mm, and a critical impact fracture velocity of 35 km / h or more when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted onto the surface of the first glass plate 11. A critical impact fracture velocity of 35 km / h or more improves resistance to flying stones. A critical impact fracture velocity of 40 km / h or more is more preferable, 45 km / h or more is even more preferable, 50 km / h or more is particularly preferable, and 60 km / h or more is most preferable. The upper limit of the critical impact fracture velocity is, for example, 120 km / h or less.

[0203] Furthermore, in this embodiment, it is preferable that the critical impact fracture speed of the laminated glass when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted against the surface of the first glass plate 11 is 55 km / h or higher. A critical impact fracture speed of 55 km / h or higher further improves resistance to flying stones. A critical impact fracture speed of 57 km / h or higher is more preferable, 60 km / h or higher is even more preferable, 62 km / h or higher is even more preferable, 64 km / h or higher is particularly preferable, 66 km / h or higher is particularly preferable, 68 km / h or higher is particularly preferable, and 70 km / h or higher is most preferable. The upper limit of the critical impact fracture speed is, for example, 120 km / h or lower.

[0204] In this embodiment, the laminated glass preferably has a total thickness of 4.5 mm or more for the first glass plate 11, the second glass plate 12, and the interlayer 13. In particular, when the laminated glass of this embodiment has the above characteristics, it is preferable that the total thickness of the first glass plate 11, the second glass plate 12, and the interlayer 13 is 4.5 mm or more. Sound insulation can be improved by having a total thickness of 4.5 mm or more. The total thickness is more preferably 4.6 mm or more, even more preferably 4.7 mm or more, even more preferably 4.8 mm or more, particularly preferably 4.9 mm or more, and most preferably 5.0 mm or more. Also, from the viewpoint of weight reduction, the total thickness is preferably 8.0 mm or less, more preferably 7.8 mm or less, even more preferably 7.6 mm or less, particularly preferably 7.4 mm or less, particularly preferably 7.2 mm or less, and most preferably 7.0 mm or less. Furthermore, if the total thickness of the first glass plate 11, the second glass plate 12, and the interlayer 13 differs depending on the location, it is preferable that the total thickness at the thinnest location be 4.5 mm or more.

[0205] Furthermore, the laminated glass of this embodiment has a first glass plate with a thickness t １ And the thickness t of the second glass plate ２ The ratio (t) １ / t ２ It is preferable that the ratio (t) is 1.5 or higher. １ / t ２ A high critical collision destruction velocity can be achieved if the ratio (t) is 1.5 or higher. １ / t ２ The ratio (t) is more preferably 2.0 or higher, even more preferably 2.5 or higher, even more preferably 3.0 or higher, particularly preferably 3.5 or higher, and most preferably 4.0 or higher. In addition, in order to bring the curvature closer when the glass after bending is made into laminated glass, the ratio (t) is used. １ / t ２ The value is preferably 6.0 or less, more preferably 5.5 or less, and even more preferably 5.0 or less.

[0206] In the case of vehicle glass applications, the laminated glass 10 of this embodiment preferably has a visible light transmittance Tv of 70% or more, as defined in ISO-9050:2003, using a D65 light source. Tv of 71% or more is more preferable, and 72% or more is even preferable. Also, Tv may be, for example, 90% or less.

[0207] In the case of vehicle glass applications, the laminated glass 10 of this embodiment preferably has a total solar radiation transmittance Tts of 70% or less, as defined in ISO-13837:2008 convention A and measured at a wind speed of 4 m / s. A total solar radiation transmittance Tts of 70% or less in the laminated glass 10 of this embodiment provides sufficient heat shielding. A Tts of 68% or less is more preferable, and 66% or less is even more preferable. Furthermore, Tts can be, for example, 55% or more.

[0208] The laminated glass 10 of this embodiment can be manufactured in the same way as conventionally known laminated glass. For example, by stacking a first glass plate 11, an interlayer 13, and a second glass plate 12 in this order, and then going through the process of heating and pressurizing, a laminated glass 10 can be obtained in which the first glass plate 11 and the second glass plate 12 are joined via the interlayer 13.

[0209] The manufacturing method for the laminated glass 10 of this embodiment may involve, for example, a step of heating and shaping the first glass plate 11 and the second glass plate 12, followed by a step of inserting the interlayer 13 between the first glass plate 11 and the second glass plate 12, and then heating and pressurizing the interlayer. By going through such a process, the laminated glass 10 may be configured such that the first glass plate 11 and the second glass plate 12 are joined via the interlayer 13.

[0210] [Applications] The glass of this embodiment is suitably usable for both vehicles and sensors, and more specifically, for use as window glass or sensor cover glass in vehicles. In particular, the glass of this embodiment has excellent fracture toughness, low viscosity and low density, making it suitable for window glass in vehicles, specifically components such as windshields, side windows, rear windows, and roof windows. Also, from a similar viewpoint, it is particularly suitable for use as cover glass for sensors such as LiDAR, cameras, and millimeter-wave radar mounted on vehicles and unmanned or manned eVTOLs (Electric Vertical Take-Off and Landing Aircraft) such as drones.

[0211] The following describes an example of using the glass of this embodiment as a window glass for a vehicle, with reference to the drawings. Figure 6 is a conceptual diagram showing a laminated glass 10 equipped with the glass of this embodiment installed in an opening 110 formed at the front of an automobile 100 and used as an automobile window glass. The laminated glass 10 used as an automobile window glass may have a housing (case) 120 containing information devices, etc., attached to its inner surface on the vehicle side to ensure the safety of the vehicle while driving.

[0212] Furthermore, the information devices housed within the housing are devices that use cameras, radar, etc., to prevent rear-end collisions and impacts with vehicles, pedestrians, obstacles, etc., in front of the vehicle, and to warn the driver of danger. Examples include information receiving devices and / or information transmitting devices, which include millimeter-wave radar, stereo cameras, infrared lasers, etc., and transmit and receive signals. The "signals" refer to electromagnetic waves, including millimeter waves, visible light, infrared light, etc.

[0213] Figure 7 is an enlarged view of portion S in Figure 6, and is a perspective view showing the portion where the housing 120 is attached to the laminated glass 10 of this embodiment. The housing 120 houses a millimeter-wave radar 201 and a stereo camera 202 as information devices. The housing 120, which houses the information devices, is usually mounted on the outside of the vehicle from the rearview mirror 150 and on the inside of the vehicle from the laminated glass 10, but it may be mounted on other parts as well.

[0214] Figure 8 is a cross-sectional view taken in a direction perpendicular to the horizontal line, including the Y-Y line in Figure 7. In the laminated glass 10, it is preferable that the first glass plate 11 is positioned on the outside of the vehicle. With the above configuration, a lightweight windshield with excellent fracture toughness can be realized. Furthermore, since the glass of this embodiment has low viscosity, bending and forming is easy when manufacturing the windshield.

[0215] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0216] <Preparation of glass plates for Examples 1 to 38> Raw materials were placed in a platinum crucible to obtain the glass composition (unit: mol%) shown in Tables 1 to 3, and melted at a temperature of 1600°C to 1650°C for 3 hours to obtain molten glass. The molten glass was poured onto a carbon plate and heated above the glass transition temperature, T １１ The following temperatures were maintained for 3 hours, followed by slow cooling at an average cooling rate of 1°C / min. Both sides of the resulting plate-shaped glass were polished to obtain glass plates with thicknesses of 2.0 mm and 4.0 mm. Examples 1 to 21 and 31 to 38 are examples, and examples 22 to 30 are comparative examples.

[0217] The glass plates obtained above were evaluated as described below, and the results are shown in Tables 1 to 3. Blank spaces in the tables indicate no measurement, and "-" indicates a B rating. ２ O ３ This indicates that measurement is not possible because it does not contain [the substance].

[0218] (1) Coordination Number of Boron The proportion of boron atoms in glass was analyzed by NMR. The NMR measurement conditions are as follows: Measurement device: JEOL ECZ700 nuclear magnetic resonance spectrometer Resonance frequency: 156.38 MHz Rotation speed: 15 kHz Probe: 3.2 mm solid Flip angle: 90° Pulse repetition waiting time: 16 sec Measurements were performed using the single pulse method, with adamantane used as an external standard (13C 28.46 ppm and 37.85 ppm). The measurement results were analyzed using JEOL NMR software Delta to perform phase correction and baseline correction, and then fitting was performed using a Gaussian function to calculate the proportion of 3-coordinate and 4-coordinate atoms and determine the average coordination number. Phase correction and baseline correction were appropriately processed by subtracting the spectrum of an empty cell that did not contain the sample. For peak fitting, the peak top was set at 20–8 ppm for 3-coordination and 5–-5 ppm for 4-coordination, and the peak width was set appropriately, specifically so that the ratio between each coordination number was no more than 1.5 times, thereby obtaining good fitting. Furthermore, from the ratio of 3-coordination boron and 4-coordination boron obtained above, B ２ O ３ Converted content of three-coordinate boron (B ３ as B ２ O ３ [mol%]) and B ２ O ３ Converted content of four-coordinate boron (B ４ as B ２ O ３ The [mol%] was calculated and recorded in Tables 1 to 3.

[0219] (2) Temperature T ２ , temperature T ４ The glass viscosity η, which is the standard for glass solubility, is 10 ２ Temperature T when the temperature is dPa·s ２ And the glass viscosity η is 10 ４ Temperature T at which dPa·s occurs ４ This was measured using a rotational viscometer.

[0220] (3) Glass transition temperature (T ｇThe values ​​were measured using TMA and determined according to the JIS R3103-3 standard (2001).

[0221] (4) Temperature T １１ , temperature T １２ The viscosity η, which is the standard for the bendability of glass, is 10 １１ Temperature T when the temperature is dPa·s １２ And the viscosity η, which is the standard for bendability, is 10 １２ Temperature T when the temperature is dPa·s １２ The values ​​were measured using the beam bending method.

[0222] (5) Average coefficient of linear expansion (CTE) at 50-350°C ５０－３５０ The values ​​were measured using a differential thermal expander (TMA) and determined according to the JIS R3102 standard (1995).

[0223] (6) A glass block of approximately 20 g, free of bubbles, cut from a density glass plate, was measured using the Archimedes method.

[0224] (7) Young's modulus: Measured at 25°C using the ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Test method for the elastic modulus of fine ceramics".

[0225] (8) Shear modulus: Measured at 25°C using the ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Test method for the elastic modulus of fine ceramics".

[0226] (9) Poisson's ratio was measured at 25°C using the ultrasonic pulse method (Olympus, DL35) in accordance with JIS R1602:1995 "Test method for the elastic modulus of fine ceramics".

[0227] (10) Fracture toughness value @ SEPB method The glass plates obtained above were measured using the Single-Edge-Precracked-Beam method (SEPB method) based on JIS R1607:2015 "Test method for room temperature fracture toughness of fine ceramics".

[0228] (11) Surface fracture energy was calculated using the above formula (1) with respect to the Young's modulus and fracture toughness values ​​obtained above.

[0229]

[0230]

[0231]

[0232] The glasses of Examples 1-21 and 31-38, which are examples, have high fracture toughness or Young's modulus, low density, and temperature T １１ The viscosity was low. In particular, the glass in examples 31-38 was ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ ]>-3.0 or ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ By satisfying ] > -3.0, the fracture toughness value or Young's modulus was particularly high, especially because the proportion of three-coordinate boron was low and the proportion of four-coordinate boron was high. On the other hand, in comparative example 22, SiO ２ The percentage is less than 70.0%, B ２ O ３ It does not contain Al ２ O ３ Because the content of 50% was less than 1.0%, MgO was greater than 5.0%, CaO was greater than 5.0%, and RO was greater than 5.0%, the fracture toughness value was inferior and the density was also high.

[0233] Also, although example 23 has excellent Young's modulus, SiO ２ The percentage is less than 70.0%, B ２ O ３ It is less than 10.0%, Al ２ O ３ Since is over 6.0%, MgO is over 5.0%, and RO is over 5.0%, T ｇ and T １２ It was expensive.

[0234] Also, in example 24, SiO ２It was over 80.0%, and R' ２ Because the oxygen content is less than 6.0%, the fracture toughness and Young's modulus are small, and furthermore, at temperature T １１ The % was high and the viscosity was high. Also, although the density of example 25 was low, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Since the value was less than -6.5, the fracture toughness and Young's modulus were smaller compared to the examples.

[0235] Also, in example 26, although the density is low, Al ２ O ３ The percentage is over 6.0%, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Since ] was less than -6.5, the Young's modulus was low. Also, although the density of Example 27 was low, SiO ２ The percentage is less than 70.0%, ２ O ３ The percentage is over 6.0%, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Since the value of ] was less than -6.5, the Young's modulus was low.

[0236] Also, in examples 28 and 29, although the density is low, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Since ] was less than -6.5, the Young's modulus was low. Also, although the density of example 30 was low, B ２ O ３ It is less than 10.0%, Al ２ O ３ The percentage is over 6.0%, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Since the value of ] was less than -6.5, the Young's modulus was low.

[0237] <Preparation of Laminated Glass> Laminated glass samples 1 to 7 were manufactured using the following procedure. Samples 1 to 4 are comparative examples, and samples 5 to 7 are examples.

[0238] (Test Example 1) As the first glass plate, a glass with a thickness of 2.0 mm and a surface roughness Ra of 2.0 nm or less, having the composition shown in Example 22 of Table 2, was used. As the interlayer, a polyvinyl butyral (PVB) with a thickness of 0.78 mm was used. As the second glass plate, a glass with a thickness of 2.0 mm and the composition shown in Example 22 of Table 2 was used. The first glass plate, interlayer, and second glass plate were laminated in this order, and after pre-bonding at 120°C for 15 minutes, pressure bonding was performed at 130°C and 1 MPa. After that, the laminated glass of Test Example 1 was produced by returning to room temperature and atmospheric pressure over 90 minutes. The total thickness of the first glass plate, second glass plate, and interlayer of the laminated glass of Test Example 1 is 4.8 mm, and the thickness of the first glass plate is t １ and the thickness t of the second glass plate ２ The ratio (t) １ / t ２ The value was 1.0.

[0239] (Test Example 2) Laminated glass was prepared in the same manner as in Test Example 1, except that the thicknesses of the first and second glass plates were changed to the values ​​shown in Table 4.

[0240] (Test Example 3) Laminated glass was prepared in the same manner as in Test Example 1, except that the thickness of the first glass plate was changed to the value shown in Table 4, and a 0.7 mm thick soda-lime glass (AGC Corporation, model number: AS2) was used as the second glass plate.

[0241] (Test Examples 4-7) Laminated glass was prepared in the same manner as in Test Example 3, except that the type of the first glass plate was changed to one of those listed in Table 4 (all with a surface roughness Ra of 2.0 nm or less).

[0242] The critical impact fracture velocity Vcrt was measured for the laminated glass plate obtained above using the following procedure. <Procedure> A tungsten carbide cemented carbide alloy with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g was injected at a speed of 20 km / h or more and impacted the surface of the first glass plate. During this impact, the crack propagation process caused by the impact of the tungsten carbide cemented carbide alloy was observed from the cross-section of the laminated glass using a high-speed camera. The test was carried out while increasing the injection speed, and when the crack that formed on the surface of the first glass plate propagated and reached the surface of the first glass plate opposite to the surface from which the tungsten carbide cemented carbide alloy impacted, it was determined to be a fracture, and the impact velocity at that time was defined as the critical impact fracture velocity Vcrt.

[0243]

[0244] The laminated glass in Test Examples 5-7, which are examples, had a higher critical impact fracture velocity compared to the comparative example.

[0245] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications are possible without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2024-177269, filed on 9 October 2024, which is incorporated herein by reference in its entirety.

[0246] 10 Laminated glass 11 First glass plate 12 Second glass plate 13 Interlayer 100 Automobile 110 Opening 120 Housing 150 Rearview mirror 201 Millimeter-wave radar 202 Stereo camera 300 Radio waves

Claims

In mole percent based on oxides, Li ２ It contains virtually no oxygen, Yes ２ :70.0~80.0% B ２ O ３ :10.0~17.0% Al ２ O ３ 1.00-6.00 MgO: 0.0-5.0% CaO: 0.0-5.0% SrO: 0.0-5.0% BaO: 0.0-5.0% Na ２ O:0.0~19.0% K ２ O:0.0~10.0% R’ ２ O:6.0~19.0% RO: 0.0~5.0% (However, RO is the sum of the contents of MgO, CaO, SrO and BaO, R' ２ O is Na ２ O and K ２ It contains the total amount of O, ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Vehicle and sensor glass with ] ≥ -6.5 (where [] means the content of each component in parentheses in mole percent on an oxide basis). ([R' ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ The vehicle and sensor glass according to claim 1, wherein the coefficient of gravity is > -3.

0. Expressed in mole percent based on oxides, Yes ２ :70.0~80.0% B ２ O ３ :10.0~17.0% Al ２ O ３ 1.00-6.00 MgO: 0.0-5.0% CaO: 0.0-5.0% SrO: 0.0-5.0% BaO: 0.0-5.0% Li ２ O: 0.0% to 15.0% Na ２ O:3.5~15.0% K ２ O:0.0~10.0% R ２ O:6.0~19.0% RO: 0.0~5.0% (However, RO is the total content of MgO, CaO, SrO and BaO, R ２ O is Li ２ O, Na ２ O and K ２ It contains the total amount of O, ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ Vehicle and sensor glass where ] ≥ -10.0 (where [] means the content of each component in parentheses in molar percentage on an oxide basis). ([R ２ O] + 1 / 2 [RO] - [Al ２ O ３ ]) - [B ２ O ３ The vehicle and sensor glass according to claim 3, wherein the coefficient of gravity is > -3.

0. The content of three-coordinate boron is B ２ O ３ The vehicle and sensor glass according to claim 1 or 3, wherein the amount is 10.0 mol% or less when converted. 　 In mole percent based on oxides, SiO ２ , B ２ O ３ and Al ２ O ３ The vehicle and sensor glass according to claim 1 or 3, wherein the total content of is 81.0 to 93.0%. 　 The content of three-coordinate boron is B ２ O ３ In terms of conversion, it is greater than 0.0 mol% and less than or equal to 7.0 mol%, The content of four-coordinate boron is B ２ O ３ The vehicle and sensor glass according to claim 1 or 3, wherein the amount is 9.5 to 15.0 mol% in conversion. 　 The vehicle and sensor glass according to claim 1 or 3, wherein the Young's modulus is 70 GPa or higher. 　 Fracture toughness value K measured by the SEPB method ＩＣ 0.85 MPa·m １／２ The above is the vehicle and sensor glass according to claim 8. 　 Glass viscosity is 10 １１ Temperature T at which dPa·s occurs １１ The vehicle and sensor glass according to claim 9, wherein the temperature is 640°C or lower. The vehicle and sensor glass according to claim 10, wherein the Young's modulus is 80 GPa or more. 　 Fracture toughness value K measured by the SEPB method ＩＣ 0.94 MPa·m １／２ The above is the vehicle and sensor glass according to claim 1 or 3. 　 The vehicle and sensor glass according to claim 12, wherein, when the surface roughness Ra is 5.0 nm or less and the thickness is 2.5 mm, the critical impact fracture velocity when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted, is 40 km / h or more. 　 The vehicle and sensor glass according to claim 12, wherein the critical impact fracture velocity when a tungsten carbide cemented carbide alloy with a tip curvature radius of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted is 60 km / h or more. 　 The vehicle and sensor glass according to claim 14, wherein the thickness is 2.5 mm or more. 　 A curved glass comprising vehicle and sensor glass according to claim 1 or 3. 　 It comprises a first glass plate, a second glass plate, and an interlayer sandwiched between the first glass plate and the second glass plate. Laminated glass wherein the first glass plate is the vehicle and sensor glass described in claim 1 or 3. 　 The laminated glass according to claim 17, wherein the surface roughness Ra of the first glass plate is 5.0 nm or less, the thickness is 2.5 mm, and the critical impact fracture velocity when a tungsten carbide cemented carbide with a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted onto the surface of the first glass plate is 40 km / h or more. 　 The laminated glass according to claim 17, wherein the critical impact fracture velocity when a tungsten carbide cemented carbide alloy having a tip radius of curvature of 200 μm, an apex angle of 120°, and a weight of 1.365 g is impacted onto the surface of the first glass plate is 60 km / h or more. 　 The laminated glass according to claim 19, wherein the sum of the thicknesses of the first glass plate, the second glass plate, and the interlayer is 4.5 mm or more. 　 The thickness t of the first glass plate １ and the thickness t of the second glass plate ２ The ratio (t) １ / t ２ The laminated glass according to claim 17, wherein the ratio is 1.5 or greater. 　 It comprises a first glass plate, a second glass plate, and an interlayer sandwiched between the first glass plate and the second glass plate. Laminated glass, wherein the first glass plate and the second glass plate are vehicle and sensor glass according to claim 1 or 3. 　 The laminated glass according to claim 17, wherein the second glass plate is soda-lime glass. 　 The laminated glass according to claim 17, wherein the second glass plate is alkali aluminosilicate glass. 　 The laminated glass according to claim 17, wherein the second glass plate is subjected to chemical strengthening treatment.

Images