Glass for buildings, vehicles, or sensors, curved glass, air-cooled tempered glass, and laminated glass

Abstract

Provided are: glass for buildings, vehicles, or sensors, the glass having excellent durability and formability; curved glass; air-cooled tempered glass; and laminated glass. This glass for buildings, vehicles, or sensors contains, in molar percentages based on oxides, SiO2, B2O3, Al2O3, MgO, CaO, SrO, BaO, Li2O, Na2O, K2O, total iron oxide converted to Fe2O3, R'2O, and RO, in specific ranges. The virtual temperature Tf is the glass transition temperature + 10°C or more, and 500°C to 750°C.

Description

Glass for buildings, vehicles or sensors, bent glass, tempered glass and laminated glass

[0001] The present invention relates to glass for buildings, vehicles or sensors, bent glass, tempered glass and laminated glass.

[0002] In recent years, glass used in mobility, such as glass for vehicles and cover glass for sensors such as LiDAR (Light Detection and Ranging), is required to have durability in order to extend its life cycle from the viewpoint of carbon neutrality. Increasing the Young's modulus of the glass is effective in improving the durability of the glass (see, for example, Patent Documents 1 and 2).

[0003] On the other hand, the glass used in the mobility is required to be formable so that it can be formed into a curved shape from the viewpoint of improving design, operability, and visibility. Curved glass is produced by a method of heating a flat glass sheet and bending it using a forming die (see Patent Document 3).

[0004] International Publication No. 2012 / 086664 Japanese Patent Application Publication No. 2019-529298 International Publication No. 2014 / 167894

[0005] However, glasses with a high Young's modulus tend to have high viscosity and density. Therefore, such glasses are not suitable for applications requiring bending and forming. For example, the glass described in Patent Document 1 has a high Young's modulus of 81 GPa or more, but a high glass transition temperature of 600°C or more. Furthermore, the glass described in Patent Document 2 has a high Young's modulus of 85 GPa or more, but a high annealing point of 800°C or more. As such, it has been difficult to achieve glasses that exhibit excellent durability and formability using conventional techniques.

[0006] In view of the above problems, an object of the present invention is to provide glass for buildings, vehicles or sensors, bent glass, tempered glass and laminated glass, which have excellent durability and formability.

[0007] The present inventors have found that the above problems can be solved by using glass having a specific composition range, and have completed the present invention.

[0008] That is, the present invention is as follows: 1. In mole % on an oxide basis, SiO ２ : 65-80% B ２ O ３ :8.0~20% 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: 0.0-10% Na ２ O: 5.0-20% K ２ O: 0.0~10% Fe ２ O ３ Total iron oxide converted to: 0.004 to 1.0% R' ２ O: 5.0 to 20% RO: 0.0 to 5.0% (wherein RO is the total content of MgO, CaO, SrO and BaO, and R' ２ O is Li ２ O, Na ２ O and K ２ 1. A glass for architecture, vehicles or sensors, which contains 1,000,000 or more of fluorine-containing compounds (which is the total content of fluorine and fluorine-containing compounds), and which has a fictive temperature Tf of at least glass transition point +10°C and at least 500°C but not more than 750°C. 2. The glass according to 1 above, which has a fictive temperature Tf of less than 650°C. 3. The glass according to 1 above, which has a fictive temperature Tf of at least 650°C. 4. The glass according to 1 above, which is bent glass. 5. The glass according to 1 above, which is tempered glass. 6. The glass according to 5 above, which has a compressive stress (CS) of at least 30 MPa and a depth of compressive stress layer (DOL) of at least 0.2 × t (mm), where t represents the thickness (mm) of the tempered glass. 7. A laminated glass comprising a first glass sheet, a second glass sheet, and an interlayer sandwiched between the first glass sheet and the second glass sheet, wherein the first glass sheet, the second glass sheet, or both are the glass according to any one of 1 to 6 above. 8. 9. The laminated glass according to 7 above, wherein the relationship between the thickness t1 of the first glass plate and the thickness t2 of the second glass plate satisfies t1≧t2. 10. The laminated glass according to 8 above, wherein the thickness t1 of the first glass plate is 3.0 mm or more, the thickness t2 of the second glass plate is 1.1 mm or more, and the sum of t1 and t2 (t1+t2) is 10 mm or less.

[0009] According to the present invention, glass for buildings, vehicles or sensors, bent glass, tempered glass and laminated glass having excellent durability and formability can be provided.

[0010] Fig. 1 is a cross-sectional view of an example of laminated glass according to an embodiment of the present invention. Fig. 2 is a conceptual diagram showing a state in which laminated glass according to an embodiment of the present invention is used as a window glass for a vehicle. Fig. 3 is an enlarged view of part S in Fig. 2. Fig. 4 is a cross-sectional view taken along line Y-Y in Fig. 3.

[0011] Hereinafter, embodiments of the present invention will be described in detail. In the following drawings, components and parts that perform the same function may be denoted by the same reference numerals, and redundant explanations may be omitted or simplified. The embodiments shown in the drawings are schematic for the purpose of clearly explaining the present invention, and do not necessarily accurately represent the size or scale of the actual product. In this specification, numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0012] Hereinafter, the glass of this embodiment will be described as an embodiment of the glass for architecture, vehicles or sensors (hereinafter, sometimes simply referred to as "glass") of the present invention. The glass of this embodiment contains, in mol % on an oxide basis, SiO ２ : 65-80% B ２ O ３ :8.0~20% 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: 0.0-10% Na ２ O: 5.0-20% K ２ O: 0.0~10% Fe ２ O ３ Total iron oxide converted to: 0.004 to 1.0% R' ２ O: 5.0 to 20% RO: 0.0 to 5.0% (wherein RO is the total content of MgO, CaO, SrO and BaO, and R'２ O is Li ２ O, Na ２ O and K ２ and a fictive temperature Tf of not less than the glass transition point +10°C and not less than 500°C and not more than 750°C.

[0013] [Glass Composition] Unless otherwise specified, the composition range of each component is expressed in mole percent based on the oxide. Furthermore, the phrase "substantially free of" each component means that the component is not contained except as an unavoidable impurity mixed in from raw materials, etc., that is, the component is not intentionally contained.

[0014] SiO ２ is a component that constitutes the network structure of the glass and is an essential component of the glass of this embodiment. ２ In the glass of this embodiment, the content of SiO ２ When the content of SiO is 65% or more, the glass structure becomes strong and the Young's modulus is increased. In addition, the density of the glass can be easily reduced, and moisture resistance and chemical durability can be secured. Furthermore, the viscosity of the glass can be reduced. Furthermore, the average linear expansion coefficient can be prevented from increasing, and thermal cracking of the glass can be suppressed. ２ The content of is more preferably 68% or more, further preferably 70% or more, even more preferably 72% or more, particularly preferably 74% or more, and most preferably 75% or more. ２ By making the content of SiO 80% or less, an increase in viscosity during glass melting is suppressed, making glass production easier and improving the formability of glass for vehicles, particularly windshields and cover glasses for sensors. ２ The content is preferably 79% or less, more preferably 78% or less, even more preferably 77% or less, and particularly preferably 76% or less.

[0015] B ２ O ３ B reduces the viscosity and density of the glass and contributes to improving the Young's modulus. It is also a component that controls the optical properties.２ O ３ The content of B is 8.0 to 20%. ２ O ３ By adding 8.0% or more of B, the viscosity and density of the glass can be reduced. In addition, as will be described later, by controlling the coordination number, the Young's modulus can be increased. ２ O ３ The content of B is preferably 9.0% or more, more preferably 10% or more, further preferably 11% or more, and particularly preferably 12% or more. ２ O ３ If the content of B is 20% or less, the alkali elements are less likely to volatilize during the melting and forming of the glass, and deterioration of the glass quality can be suppressed. In addition, acid resistance and alkali resistance can be improved. ２ O ３ The content is preferably 18% or less, more preferably 17% or less, even more preferably 16% or less, particularly preferably 15% or less, and most preferably 14% or less.

[0016] In glass, boron can have an oxygen coordination number of three or four. Tetracoordinated boron enters the glass framework and forms a tetrahedral structure. Because the tetrahedral structure is negatively charged, the charge is compensated for by alkali metal ions or alkaline earth metal ions. Therefore, tetracoordinated boron forms a three-dimensional glass structure with almost no non-bridging oxygen. On the other hand, tricoordinated boron has non-bridging oxygen in glass and is known to form a planar structure such as a boroxol ring. As the content of tricoordinated boron increases, the Young's modulus decreases, while as the content of tetracoordinated boron increases, the Young's modulus tends to increase. As the Young's modulus decreases, the formability of the glass improves. The reason why the Young's modulus decreases with an increase in the content of tricoordinated boron is thought to be that the proportion of tetracoordinated boron decreases and the proportion of tricoordinated boron increases, increasing the amount of non-bridging oxygen and reducing the ion packing fraction and bond dissociation energy that contribute to the Young's modulus. In the glass of this embodiment, B ２ O ３ The converted tricoordinate boron content (B ３ as B２ O ３ ) is more preferably 10% or less, even more preferably 9.5% or less, even more preferably 9.0% or less, particularly preferably 8.5% or less, even more preferably 8.0% or less, even more preferably 7.5% or less, particularly preferably 7.0% or less, and most preferably 6.5% or less. Furthermore, from the viewpoint of suppressing an increase in viscosity due to increased glass network formation by tetracoordinated boron, the content of tricoordinated boron is preferably 1.5% or more, more preferably 2.0% or more, even more preferably 2.5% or more, even more preferably 3.0% or more, particularly preferably 3.5% or more, and most preferably 4.0% or more. The proportions of tricoordinated boron and tetracoordinated boron in glass can be measured by Nuclear Magnetic Resonance (NMR).

[0017] Al ２ O ３ is a component that constitutes the network structure of the glass and is an essential component of the glass of this embodiment. ２ O ３ In the glass of this embodiment, the content of Al is 1.0 to 6.0%. ２ O ３ By setting the Al content to 1.0% or more, the Young's modulus can be increased. In addition, the weather resistance, moisture resistance, and chemical durability are improved. Furthermore, the average linear expansion coefficient does not become too large, which can suppress thermal cracking of the glass, and also makes it possible to perform chemical strengthening treatment using ion exchange. ２ O ３ The content of Al is preferably 1.5% or more, more preferably 1.8% or more, even more preferably 2.0% or more, particularly preferably 2.3% or more, and most preferably 2.5% or more. ２ O ３ By making the content of Al 6.0% or less, an increase in viscosity during glass melting is suppressed, facilitating glass production, and also improving the formability of glass for vehicles, particularly windshields and cover glass for sensors. ２ O ３By keeping the content of Al low, the ratio of tetrahedral boron can be increased, which is preferable. ２ O ３ The content is preferably 5.0% or less, more preferably 4.5% or less, even more preferably 4.0% or less, particularly preferably 3.5% or less, and most preferably 3.0% or less.

[0018] MgO is a component that reduces the viscosity of the glass and contributes to improving the Young's modulus. Furthermore, due to its high electronegativity, it is a component that increases the proportion of tricoordinated boron among alkaline earth metals. The MgO content in the glass of this embodiment is 0.0 to 5.0%. By including MgO in the glass of this embodiment, the viscosity of the glass can be reduced and the melting of glass raw materials can be promoted. In addition, the Young's modulus and moisture resistance can be improved. When MgO is included in the glass of this 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. Furthermore, if the MgO content in the glass of this embodiment is 5.0% or less, the glass is less susceptible to devitrification and an excessive increase in viscosity during glass melting is suppressed, facilitating glass production. Furthermore, the formability of vehicle glass, particularly windshields and cover glass for sensors, is improved. The MgO content is preferably 4.0% or less, more preferably 3.0% or less, further preferably 2.5% or less, particularly preferably 2.0% or less, and most preferably 1.5% or less.

[0019] CaO is a component that reduces the viscosity of the glass. Furthermore, due to its high electronegativity, it is the second most effective component among alkaline earth metals after MgO in increasing the proportion of tricoordinated boron. The CaO content in the glass of this embodiment is 0.0 to 5.0%. The inclusion of CaO in the glass of this embodiment improves the meltability of the glass raw materials and further reduces the viscosity, thereby improving formability. When CaO is included in the glass of this embodiment, its 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. Furthermore, by keeping the CaO content in the glass of this embodiment to 5.0% or less, an increase in the density of the glass can be suppressed, and the average linear expansion coefficient can be reduced, thereby suppressing thermal cracking of the glass. Furthermore, the proportion of tricoordinated boron can be kept low. The CaO content in the glass of the present embodiment 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.

[0020] SrO is a component that reduces the viscosity of the glass. The SrO content in the glass of this embodiment is 0.0 to 5.0%. In the glass of this embodiment, by setting the SrO content to 5.0% or less, an increase in the density of the glass can be suppressed. In the glass of this embodiment, the SrO 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 0.50% or less, and most preferably substantially free of SrO. In the glass of this embodiment, "substantially free of SrO" means that the SrO content in the glass is 0.10 mol% or less. In the glass of this embodiment, when SrO is contained, 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.

[0021] BaO is a component that reduces the viscosity of the glass. The BaO content in the glass of this embodiment is 0.0 to 5.0%. In the glass of this embodiment, by setting the BaO content to 5.0% or less, an increase in the density of the glass can be suppressed. In the glass of this 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 0.50% or less, and most preferably substantially free of BaO. In the glass of this embodiment, "substantially free of BaO" means that the BaO content in the glass is 0.10 mol% or less. In the glass of this embodiment, when BaO is contained, 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.

[0022] In the glass of this embodiment, the total content of MgO, CaO, SrO, and BaO (hereinafter sometimes referred to as RO) is 0.0 to 5.0%. By including at least one selected from MgO, CaO, SrO, and BaO, the Young's modulus can be increased. When at least one selected from MgO, CaO, SrO, and BaO 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. Furthermore, if the RO content is 5.0% or less, an increase in the density of the glass can be suppressed, thereby improving the crack resistance of the glass. The RO content 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.

[0023] Li ２ O is a component that improves the melting property of glass and reduces the viscosity. In addition, O is a component that increases the Young's modulus and contributes to the average linear expansion coefficient of glass. Furthermore, the strength of glass can be increased by performing a chemical strengthening treatment by ion exchange with Na ions. Li in the glass of this embodiment ２The content of O is 0.0 to 10%. ２ By containing O, Na ２ O and K ２ It can reduce the viscosity of the glass compared to O. ２ The content of O 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. ２ By making the O content 10% or less, it is possible to suppress thermal cracking of the glass due to an excessively large average linear expansion coefficient. Furthermore, it is possible to suppress the formation of a crystalline phase containing Li during the production of the glass, thereby improving the manufacturability of the glass. ２ The O content is preferably 9.0% or less, 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.

[0024] Na ２ O is a component that improves the melting property of glass and reduces the viscosity, and also makes it easier to increase the Young's modulus and contributes to the average linear expansion coefficient of glass. Furthermore, the strength of the glass can be increased by performing a chemical strengthening treatment by ion exchange with K ions. In the glass of this embodiment, Na ２ The content of O is 5.0 to 20%. ２ By including O, the viscosity of the glass can be reduced. In addition, the Young's modulus and the average coefficient of linear expansion can be increased. ２ The O content is preferably 5.5% or more, more preferably 6.0% or more, even more preferably 6.5% or more, even more preferably 6.8% or more, particularly preferably 7.0% or more, particularly preferably 7.2% or more, and most preferably 7.5% or more. ２ By keeping the O content at 20% or less, thermal cracking of the glass due to an excessively large average linear expansion coefficient can be suppressed. In addition, the moisture resistance of the glass is improved, making it suitable for use as glass exposed to the atmosphere for long periods of time, such as vehicle window glass. ２The O content is preferably 18% or less, more preferably 15% or less, even more preferably 13% or less, even more preferably 12% or less, particularly preferably 11% or less, and most preferably 10% or less.

[0025] K ２ O is a component that improves the meltability of the glass and reduces the viscosity, and also makes it easier to increase the Young's modulus and contributes to the average linear expansion coefficient of the glass. ２ The content of O is 0.0 to 10%. ２ By including O, the viscosity of the glass can be reduced. In addition, the Young's modulus and the average coefficient of linear expansion can be increased. ２ When O is contained, the content is preferably 0.30% or more, more preferably 0.50% or more, even more preferably 0.70% or more, particularly preferably 0.90% or more, and most preferably 1.0% or more. ２ O is Li ２ O and Na ２ Compared to O, it has the effect of increasing the average linear expansion coefficient and density. ２ By keeping the O content at 10% or less, thermal cracking of the glass due to an excessively large average linear expansion coefficient 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.

[0026] In the glass of this embodiment, Li ２ O, Na ２ O and K ２ The total content of O (hereinafter referred to as R' ２ R' is 5.0 to 20%. ２ When O is 5.0% or more, the Young's modulus is increased and the viscosity of the glass is reduced, thereby improving the moldability. ２ O is preferably 5.5% or more, more preferably 6.0% or more, even more preferably 6.5% or more, even more preferably 7.0% or more, particularly preferably 7.5% or more, and most preferably 8.0% or more.２ If the O content is 20% or less, an increase in density can be suppressed and the moisture resistance of the glass can be further improved. ２ O is preferably 19% or less, more preferably 17% or less, even more preferably 15% or less, and particularly preferably 14% or less, 13% or less, 12% or less, and most preferably 11% or less.

[0027] Fe ２ O ３ is a component that improves the heat insulating properties of the glass and also contributes to the color of the glass. ２ O ３ The total iron oxide content calculated as Fe is 0.004 to 1.0%. ２ O ３ The total iron oxide content converted to ferrous iron is the total iron oxide content of FeO, which is an oxide of divalent iron, and Fe, which is an oxide of trivalent iron. ２ O ３ In the glass of this embodiment, Fe ２ O ３ When the total iron oxide content, calculated as Fe, is 0.004% or more, heat insulation properties are improved, design properties are imparted, and heat is easily transferred to the glass during bending of the glass, thereby improving formability. ２ O ３ By setting the total iron oxide content, calculated as % by weight, to 1.0% or less, it is possible to suppress a decrease in light transmittance in the visible range.

[0028] When the glass of this embodiment is used as architectural glass, Fe is preferably used in order to improve heat insulation properties and provide design. ２ O ３ The total iron oxide content calculated as a percentage of total iron oxide is preferably 0.008% or more, more preferably 0.016% or more, even more preferably 0.020% or more, even more preferably 0.023% or more, particularly preferably 0.031% or more, particularly preferably 0.035% or more, and most preferably 0.040% or more. Furthermore, when the glass of this embodiment is used for architectural glass, from the viewpoint of further suppressing the decrease in light transmittance in the visible range, Fe ２ O ３The total iron oxide content, calculated as % of iron oxide, is preferably 0.80% or less, more preferably 0.60% or less, even more preferably 0.40% or less, particularly preferably 0.20% or less, and most preferably 0.10% or less.

[0029] When the glass of this embodiment is used as a vehicle glass, Fe is preferably used in order to improve heat insulation, impart designability, and facilitate heat transfer to the glass during bending of the glass. ２ O ３ The total iron oxide content calculated as Fe is preferably 0.020% or more, more preferably 0.040% or more, even more preferably 0.10% or more, particularly preferably 0.12% or more, particularly preferably 0.13% or more, and most preferably 0.14% or more. When the glass of this embodiment is used for a vehicle glass, Fe ２ O ３ From the viewpoint of further suppressing a decrease in light transmittance in the visible region, the total iron oxide content converted into % is preferably 0.80% or less, more preferably 0.60% or less, even more preferably 0.40% or less, particularly preferably 0.30% or less, and most preferably 0.25% or less.

[0030] When the glass of this embodiment is used as a glass for sensors (for example, a cover glass for LiDAR or a camera), from the viewpoint of making it easier to melt raw materials during glass production and from the viewpoint of further reducing the amount of expensive high-purity raw materials used, Fe ２ O ３ The total iron oxide content in terms of Fe is more preferably 0.0040% or more, and even more preferably 0.0042% or more. ２ O ３ The total iron oxide content, calculated as a carbon content, is more preferably 0.020% or less, further 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.

[0031] The glass of this embodiment contains Fe ２ O ３ Fe in total iron oxide converted to ２ O ３It is preferable that the mass percentage (%) of divalent iron converted to Fe (hereinafter referred to as Fe-Redox) is 15% or more. ２ O ３ Fe relative to the total iron oxide content converted ２ O ３ Conversion Fe ２＋ The content ratio is 15% or more. Fe-Redox has absorption in the near infrared region. ２＋ Since the content of β-glucan can be increased, heat is more easily transferred to the glass melt during glass production, improving manufacturability. In addition, the transmittance in the near-infrared region is reduced, improving heat insulation, making the glass suitable for applications requiring heat insulation, such as architectural and vehicle glass.

[0032] When the glass of this embodiment is used as architectural or vehicle glass, the Fe-Redox is more preferably 20% or more, further preferably 22% or more, particularly preferably 24% or more, and is preferably 50% or less. By having the Fe-Redox content of 50% or less, deterioration of the melting equipment can be suppressed and the amount of SO in the fining agent can be reduced. ３ When Fe-Redox is used, amber coloring can be suppressed and a decrease in visible light transmittance can be suppressed. Fe-Redox is more preferably 45% or less, further preferably 40% or less, and particularly preferably 38% or less.

[0033] When the glass of this embodiment is used as a glass for sensors, the Fe-Redox is more preferably 16% or more, even more preferably 17% or more, particularly preferably 18% or more, and is preferably 35% or less. By keeping the Fe-Redox at 35% or less, a decrease in transmittance in the near-infrared region can be suppressed. The Fe-Redox is more preferably 30% or less, even more preferably 28% or less, particularly preferably 25% or less.

[0034] Fe-Redox can be adjusted by the raw material composition, melting temperature, and melting atmosphere. Fe-Redox can also be adjusted by using a reducing agent such as coke or ammonium chloride as a raw material to control the degree of oxidation-reduction of the glass melt.

[0035] [Other Components] The glass of the present embodiment may contain components other than the above components (hereinafter also referred to as "other components"). Examples of other components include 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 , S.O. ３ , Cl, F, SnO ２ , Sb ２ O ３ The metal ions or oxides may be used.

[0036] Other components may be contained for various purposes (e.g., clarification and coloring, imparting chemical durability, etc.), for example, preferably in a total amount of 3.0% or less. If the total content of other components is 3.0% or less, the properties required for architectural glass, vehicle glass, and sensor glass can be maintained. The total content of other components is more preferably 2.5% or less, even more preferably 2.0% or less, even more preferably 1.5% or less, particularly preferably 1.0% or less, particularly preferably 0.80% or less, and most preferably 0.50% or less. In addition, in order to prevent environmental impact, As ２ O ３ The content of each of PbO is preferably less than 0.0010%, and more preferably substantially none is contained.

[0037] The glass of this embodiment is ZrO ２ ZrO ２ is a component that improves chemical durability. ２When ZrO is contained, its content is preferably 0.010% or more, more preferably 0.050% or more, further preferably 0.10% or more, and particularly preferably 0.20% or more. 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.

[0038] The glass of this embodiment is Y ２ O ３ Y ２ O ３ is a component that increases the Young's modulus. ２ O ３ When Y is contained, its content is preferably 0.10% or more, more preferably 0.20% or more, further preferably 0.30% or more, and particularly preferably 0.40% or more. ２ O ３ The content is preferably 2.0% or less, more preferably 1.5% or less, further preferably 1.0% or less, particularly preferably 0.80% or less.

[0039] In the glass of this embodiment, if NiO is contained, NiS may be generated, which may cause glass breakage, so the NiO content is preferably 0.0080% or less, more preferably 0.0040% or less, even more preferably 0.0020% or less, and particularly preferably substantially zero.

[0040] The glass of this embodiment contains CeO ２ It may contain CeO ２ Since CeO absorbs light in the ultraviolet region, it reduces the ultraviolet transmittance Tuv and improves UV blocking performance. It also acts as an oxidizing agent and can control Fe-Redox. ２ When CeO is contained, its content is preferably 0.010% or more, more preferably 0.020% or more, further preferably 0.040% or more, and particularly preferably 0.070% or more. ２may absorb ultraviolet light, causing solarization and reducing transmittance in the visible range. ２ The content is preferably 0.25% or less, more preferably 0.18% or less, further preferably 0.14% or less, particularly preferably 0.10% or less.

[0041] The glass of this embodiment is Cr ２ O ３ Cr ２ O ３ acts as an oxidizing agent and can control Fe-Redox. ２ O ３ When Cr is contained, its content is preferably 0.0020% or more, and more preferably 0.0040% or more. ２ O ３ Since Fe has coloration in the visible range, there is a risk of a decrease in visible light transmittance. ２＋ Therefore, the glass of the present embodiment is preferably made of Cr. ２ O ３ When it is contained, the content is preferably 0.020% or less, more preferably 0.016% or less, further preferably 0.012% or less, and particularly preferably 0.0080% or less.

[0042] The glass of this embodiment is SnO ２ It may contain SnO ２ acts as a reducing agent and can control Fe-Redox. ２ When SnO is contained, its content is preferably 0.010% or more, more preferably 0.040% or more, further preferably 0.060% or more, and particularly preferably 0.080% or more. ２ In order to suppress defects caused by SnO in the glass of this embodiment, ２ The content of is preferably 0.40% or less, more preferably 0.30% or less, further preferably 0.20% or less, particularly preferably 0.15% or less.

[0043] The glass of this embodiment is SO ３ SO ３acts as a fining agent to improve the bubble quality of the glass. ３ When SO is contained, its content is preferably 0.0010% or more, more preferably 0.0040% or more, further preferably 0.0070% or more, and particularly preferably 0.015% or more. ３ If the Fe-Redox is high, amber coloring occurs, turning the glass brown, and there is a risk of a decrease in visible light transmittance. ３ When it is contained, the content is preferably 0.070% or less, more preferably 0.060% or less, further preferably 0.050% or less, and particularly preferably 0.040% or less.

[0044] The glass of this embodiment may contain Cl. Cl acts as a fining agent and improves the bubble quality of the glass. When the glass of this embodiment contains Cl, the Cl 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 volatilized from the glass melt may be easily dissolved. ２ The gas may corrode surrounding members. When the glass of the present embodiment contains Cl, the Cl 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.

[0045] [Characteristics] (Fictive Temperature Tf) The glass of this embodiment has a fictive temperature Tf of glass transition point +10°C or more and 500°C or more and 750°C or less. If the fictive temperature is too high, the proportion of tricoordinated boron increases, resulting in small Young's modulus and fracture toughness values ​​and reduced durability. On the other hand, if the fictive temperature is too low, the amount of tetracoordinated boron increases too much, increasing the viscosity of the glass and reducing formability. The glass of this embodiment exhibits excellent durability and formability by having a fictive temperature Tf of glass transition point +10°C or more and 500°C or more and 750°C or less.

[0046] The glass of the present embodiment preferably has a fictive temperature Tf of the glass transition point + 20°C or more, more preferably the glass transition point + 30°C or more, even more preferably the glass transition point + 50°C or more, particularly preferably the glass transition point + 75°C or more, and most preferably the glass transition point + 100°C or more.

[0047] In one aspect of the glass of this embodiment, the fictive temperature Tf is preferably 740°C or lower, more preferably 725°C or lower, even more preferably 700°C or lower, and particularly preferably 675°C or lower. A fictive temperature Tf of 750°C or lower increases the proportion of tetrahedral boron, thereby increasing the Young's modulus and fracture toughness, thereby further enhancing durability. In this aspect, from the viewpoint of increasing the proportion of trihedral boron to reduce the Young's modulus and glass viscosity and further improving formability, the fictive temperature Tf is preferably 550°C or higher, more preferably 575°C or higher, even more preferably 600°C or higher, and particularly preferably 625°C or higher. Specific examples of such glass include glass that has been subjected to bending and glass that has been tempered by air-cooling. As described above, the coordination number of boron can be adjusted by the fictive temperature Tf. From this viewpoint, one aspect of the glass of this embodiment includes, for example, an aspect in which the fictive temperature Tf is lower than 650°C or an aspect in which the fictive temperature Tf is 650°C or higher.

[0048] At high temperatures, glass has low viscosity and is in a liquid state, at which point its structure is coarse. As it cools, the structure of the glass solidifies while becoming denser. This structural change in glass occurs as the glass attempts to transition to its most stable state at that temperature. However, if the cooling rate of glass is high, the glass solidifies before it reaches a stable structure, and the glass structure becomes fixed in its high-temperature state. The temperature corresponding to this solidified glass structure is called the fictive temperature Tf. In other words, even for glasses with the exact same composition, the fictive temperature Tf varies depending on the heat treatment used in the manufacturing process. In this way, the structure of the glass varies depending on the heat treatment, and its physical properties also differ.

[0049] Fictive temperature can be measured by known methods. An example of a method for measuring fictive temperature Tf will be described below. To measure fictive temperature, a calibration curve showing the relationship between fictive temperature and refractive index nd at the d-line (587.6 nm) is created using a reference glass substrate, and the refractive index nd of the glass substrate to be measured is measured and the fictive temperature Tf can be calculated using the calibration curve. First, a plurality of glass pieces with the same glass composition but different fictive temperatures are prepared by a method in which glass held at a constant temperature is rapidly cooled from that temperature. Since the fictive temperatures of these glass pieces are the temperatures at which they were held before rapid cooling, a calibration curve is created by measuring the refractive index of these glass pieces and plotting the refractive index against the fictive temperature. Next, the refractive index nd of the glass substrate to be measured is measured, and the fictive temperature Tf can be calculated using the calibration curve. The refractive index can be measured using a precision refractometer (KPR-2000 manufactured by Kalnew) or the like.

[0050] More specifically, the virtual temperature T ｆ is obtained by the following steps 1) to 3). 1) First, i (i≧2) test pieces are prepared from a glass sample whose fictive temperature is to be measured, and each is held at a different cooling start temperature until the refractive index reaches equilibrium, and then cooled at a cooling rate of 1000°C / min or more. If the cooling start temperature is lower than the glass transition temperature, a sufficiently long holding time is required, so the cooling start temperature is preferably set to a temperature 10°C to 200°C higher than the glass transition temperature. 2) For the glass cooled under the conditions described in 1), the refractive index n ｄ Measure the respective cooling start temperatures T ｉ The refractive index n of the glass rapidly cooled from the cooling start temperature ｄｉ 3) Next, the fictive temperature T ｆ The refractive index n of a test piece cut out from the glass to be measured and polished is ｄ The fictive temperature T of the glass is measured using a calibration curve. ｆ Determine.

[0051] (Average Coefficient of Linear Expansion) The average coefficient of linear expansion (CTE) of the glass of this embodiment at 50 to 350°C is 40 × 10 －７ / °C or more, and －７ / °C or more is more preferable, and 48 x 10 －７ / °C or more is more preferable, and 50 x 10 －７ / °C or more is particularly preferred, and 52 x 10 －７ / °C or more is particularly preferred, and 54 x 10 －７ / °C or more is particularly preferred, and 55 x 10 －７ / °C or more. －７ / °C or more, the formability and tempering performance can be further improved. In addition, the average coefficient of linear expansion (CTE) of the glass of this embodiment at 50 to 350°C is 70 × 10 －７ / °C or less, and －７ / °C or less is more preferable, and 65 × 10 －７ / °C or less is more preferable, and 62 x 10 －７ / °C or less, and more preferably 61 x 10 －７ / °C or less is particularly preferred, and 60 x 10 －７ / °C or less. The average linear expansion coefficient is 70 x 10 －７ / °C or less, cracking due to heat shock can be suppressed. Furthermore, when the glass of this embodiment is used as a bent glass, the difference in thermal expansion due to the difference in thermal history within the surface can be suppressed, and the bent glass can be made to have good dimensional and surface accuracy. In order to make the average linear expansion coefficient within the above range, for example, the SiO ２ Adjust the content of R' ２ O and RO or Al ２ O ３ The content of B ２ O ３ The methods include adjusting the content or the coordination number of boron, and adjusting the fictive temperature Tf.

[0052] (Density) The density of the glass of this embodiment is 2.50 g / cm ３ It is preferable that the density is 2.45 g / cm or less. ３ More preferably, 2.40 g / cm or less ３ More preferably, 2.38 g / cm ３ Even more preferably, 2.37 g / cm ３More preferably, 2.36 g / cm ３ The following is particularly preferred: 2.35 g / cm ３ Most preferred is a density of 2.50 g / cm ３ By setting the density of the glass to 2.23 g / cm or less, formability can be further improved and increases in fuel consumption and electricity consumption due to weight increase can be further suppressed. ３ More than 2.25 g / cm ３ More preferably, 2.27 g / cm ３ More than 2.30 g / cm is particularly preferred. ３ Generally, glass having a low Young's modulus tends to have a low density. However, the glass of the present embodiment has a low Young's modulus R' of the glass component. ２ Composition or content of O or RO, B ２ O ３ By adjusting the content of , the coordination number of boron, and the fictive temperature Tf, it is possible to achieve a low Young's modulus while ensuring a sufficient density.

[0053] (Young's Modulus) The Young's modulus of the glass of this embodiment is preferably 80 GPa or less, more preferably 78 GPa or less, even more preferably 76 GPa or less, particularly preferably 74 GPa or less, and most preferably 72 GPa or less, from the viewpoints of improving the formability of the glass and suppressing deformation and cracking when the glass is subjected to an external force. Furthermore, the Young's modulus of the glass of this embodiment is preferably 55 GPa or more, more preferably 60 GPa or more, even more preferably 62 GPa or more, even more preferably 64 GPa or more, particularly preferably 66 GPa or more, and most preferably 68 GPa or more, from the viewpoints of increasing the rigidity of the glass. In order to set the Young's modulus within the above range, the proportion of tricoordinated boron can be increased, the fictive temperature Tf can be adjusted, and R O and R' can be adjusted. ２ Examples of methods include adjusting the type and amount of O. Young's modulus can be measured by an ultrasonic pulse method based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0054] (Rigidity Modulus) The rigidity modulus of the glass of this embodiment is preferably 24 GPa or more, more preferably 25 GPa or more, even more preferably 26 GPa or more, particularly preferably 27 GPa or more, and most preferably 28 GPa or more. If the rigidity modulus is 24 GPa or more, the glass is less likely to deform when subjected to an external force. Furthermore, when the glass is subjected to an external force, deformation occurs and energy is consumed, thereby suppressing cracking. Therefore, the rigidity modulus of the glass of this embodiment is preferably 35 GPa or less, more preferably 34 GPa or less, even more preferably 33 GPa or less, and particularly preferably 32 GPa or less. The rigidity modulus can be measured by an ultrasonic pulse method based on JIS R1602:1995 "Testing Method for Elastic Modulus of Fine Ceramics."

[0055] (Poisson's ratio) The Poisson's ratio of the glass of this embodiment is preferably 0.25 or less, more preferably 0.24 or less, even more preferably 0.23 or less, particularly preferably 0.22 or less, particularly preferably 0.21 or less, particularly preferably 0.20 or less, and most preferably 0.19 or less. The smaller the Poisson's ratio, the smaller the stress generated when an external force is applied to the glass. The Poisson's ratio can be measured by an ultrasonic pulse method based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0056] (T ｇ ) the glass transition temperature (T ｇ ) is preferably in the range of 460 to 590°C. ｇ If the temperature is within this predetermined range, the glass can be bent within the range of normal manufacturing conditions. ｇ By ensuring that the temperature is 460°C or higher, the alkali metal content or alkaline earth metal content does not become too large, and the average linear expansion coefficient of the glass can be prevented from increasing. In addition, moisture resistance and devitrification of the glass are suppressed, and formability is improved. ｇ is more preferably 480° C. or higher, further preferably 490° C. or higher, and particularly preferably 500° C. or higher. From the viewpoint of preventing the bending temperature of the glass from becoming excessive and facilitating production, T ｇis 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.

[0057] (T １１ In the glass of this embodiment, the glass viscosity η, which is the standard for bending workability, is 10 １１ [dPa s] Temperature T １１ is preferably 650°C or less, more preferably 645°C or less, even more preferably 640°C or less, even more preferably 635°C or less, particularly preferably 630°C or less, and most preferably 625°C or less. １１ By keeping the temperature at 650°C or less, bending forming can be performed at a low temperature. １１ As a method for lowering the temperature to 650° C. or less, for example, the R′ of the glass component ２ Increased O and RO content, Al ２ O ３ A method for reducing the content of R' ２ Among O, Li ２ Method for incorporating O, SiO ２ A method for reducing the content of ２ O ３ In addition, from the viewpoint of maintaining the fracture toughness of the glass, preventing the average linear expansion coefficient of the glass from becoming too large, and the firing temperature of the black ceramic printed on the windshield, it is possible to adjust the T １１ The temperature is preferably 580°C or higher, more preferably 585°C or higher, even more preferably 590°C or higher, particularly preferably 595°C or higher, and most preferably 600°C or higher.

[0058] When the glass of the present invention is used as a glass for a vehicle, the shape of the glass of the present invention is not particularly limited. ２ More than 0.45m is preferable. ２ More preferably, 0.90 m or more ２The above is even more preferable. When the area of ​​the glass is within the above range, it can be adapted to various vehicle models. Furthermore, if the area of ​​the glass is too large, the glass becomes difficult to handle, the temperature distribution during heating becomes non-uniform, the dimensional accuracy after bending becomes poor, and so on, making bending more difficult. Therefore, the glass of the present invention is designed so that the area of ​​the main surface is within 10 m ２ Preferably less than 7m ２ Less than 5m is more preferable. ２ The following is even more preferred:

[0059] When the glass of the present invention is used as a glass for a sensor, the shape of the glass of the present invention is not particularly limited, but the area of ​​the main surface is preferably 0.00010 m ２ More than 0.010 m is preferable. ２ More preferably, 0.020 m or more ２ More preferably, 0.040 m or more ２ More than 0.090 m is particularly preferable. ２ The above is most preferable. When the glass area is within the above range, it can be used as a cover glass for various LiDARs. Furthermore, if the glass area is too large, the temperature distribution during heating becomes uneven, the dimensional accuracy after bending becomes poor, and so on, making bending more difficult. Therefore, the glass of the present invention is designed so that the area of ​​the main surface is within 1.0 m ２ Preferably less than 0.90 m ２ Less than 0.80 m is more preferable. ２ The following is even more preferred:

[0060] The glass of this embodiment preferably has a thickness of 2.5 mm or more. In particular, when the glass of this embodiment has the above-mentioned properties, the thickness of the glass is preferably 2.5 mm or more. A glass thickness of 2.5 mm or more can improve the critical impact fracture speed of glass having a high fracture toughness value. The thickness of the glass is more preferably 2.8 mm or more, even more preferably 2.9 mm or more, even more preferably 3.0 mm or more, particularly 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. Furthermore, from the viewpoint of suppressing increases in fuel economy and electricity consumption due to an increase in the weight of the glass, the thickness of the glass of 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. Examples of methods for adjusting the thickness of the glass include a method of adjusting the thickness of the glass using the float method or down-draw method described below, and a method of polishing the glass in the thickness direction using a grinding stone and then polishing it to a mirror finish using an abrasive such as cerium oxide. 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.

[0061] [Manufacturing Method] The manufacturing method of glass of this embodiment preferably includes a procedure for adjusting the fictive temperature. Examples of the procedure for adjusting the fictive temperature of glass include the following procedure (A) or procedure (B). <Procedure (A)> Procedure (A) includes the following procedures (A-1) and (A-2). (A-1) Predetermined glass raw materials are blended and melted, and then formed into a sheet glass. (A-2) Adjusting the cooling temperature profile of the glass during the forming in (A-1). In procedure (A), the fictive temperature of the glass can be increased, for example, by increasing the cooling rate near the glass transition point (for example, between the annealing point and the strain point), specifically, preferably by setting the cooling rate to 10°C / min or more. The cooling rate is more preferably 30°C / min, even more preferably 50°C / min or more, particularly preferably 70°C / min or more, and most preferably 100°C / min or more. Furthermore, from the viewpoint of suppressing a decrease in Young's modulus and fracture toughness due to an increase in the proportion of tricoordinated boron, the cooling rate is preferably 800°C / min or less, more preferably 600°C / min or less, even more preferably 400°C / min or less, particularly preferably 300°C / min or less, and most preferably 200°C / min or less.

[0062] <Procedure (B)> Procedure (B) includes the following (B-1) and (B-2): (B-1) blending and melting predetermined glass raw materials, and then forming them into sheet glass. (B-2) heating the sheet glass formed in (B-1) up to a predetermined cooling start temperature, maintaining that temperature, and then cooling it.

[0063] Known methods for forming the molten glass into sheet glass in (B-1) include, for example, the float method, the fusion method, and the roll-out method.

[0064] In step (B), when the fictive temperature of the glass is to be lowered, the cooling start temperature may be lowered. From the viewpoint of suppressing cracking of the glass during cooling, the cooling start temperature is preferably Tg + 20 ° C. or higher, more preferably Tg + 30 ° C. or higher, even more preferably Tg + 50 ° C. or higher, particularly preferably Tg + 75 ° C. or higher, and most preferably Tg + 100 ° C. or higher. Furthermore, from the viewpoint of suppressing a decrease in the Young's modulus and fracture toughness value due to an increase in the proportion of tricoordinated boron and a decrease in density, the cooling start temperature is preferably Tg + 200 ° C. or lower. Furthermore, it is preferably Tg + 190 ° C. or lower, more preferably Tg + 180 ° C. or lower, even more preferably Tg + 170 ° C. or lower, particularly preferably Tg + 160 ° C. or lower, and most preferably Tg + 150 ° C. or lower.

[0065] The required holding time in step (B) varies depending on the cooling start temperature, but is, for example, preferably 10 seconds or more, more preferably 60 seconds or more, even more preferably 120 seconds or more, particularly preferably 180 seconds or more, and most preferably 240 seconds or more. Also, for example, it is preferably 600 seconds or less, more preferably 500 seconds or less.

[0066] In step (B), the fictive temperature of the glass can be adjusted by adjusting the cooling rate. In order to control the fictive temperature, the cooling rate is preferably 1.0°C / sec or more, more preferably 5.0°C / sec or more, even more preferably 20°C / sec or more, particularly preferably 40°C / sec or more, and most preferably 60°C / sec or more. In addition, in order to uniform the temperature distribution of the glass during cooling, the cooling rate is preferably 200°C / sec or less, more preferably 180°C / sec or less, even more preferably 160°C / sec or less, particularly preferably 150°C / sec or less, and most preferably 140°C / sec or less.

[0067] Specific examples of the method for carrying out (B-2) include air-cooling and bending.

[0068] When (B-2) is performed by air-cooling tempering, the cooling start temperature is preferably Tg + 50°C or higher, more preferably Tg + 100°C or higher, and even more preferably Tg + 120°C or higher, from the viewpoint of increasing compressive stress. Furthermore, the cooling start temperature is preferably Tg + 250°C or lower, from the viewpoint of preventing softening of the glass during air-cooling tempering. Furthermore, it is preferably Tg + 200°C or lower, more preferably Tg + 180°C or lower, even more preferably Tg + 170°C or lower, and particularly preferably Tg + 160°C or lower. When (B-2) is performed by air-cooling tempering, the holding time is preferably 10 / (cooling start temperature - Tg) seconds or higher, more preferably 30 / (cooling start temperature - Tg) seconds or higher, and particularly preferably 60 / (cooling start temperature - Tg) seconds or higher. Furthermore, for example, the cooling rate is preferably 600 / (cooling start temperature - Tg) seconds or less, more preferably 300 / (cooling start temperature - Tg) seconds or less, and particularly preferably 180 / (cooling start temperature - Tg) seconds or less. When (B-2) is performed by air-cooling tempering, the cooling rate is preferably 10°C / sec or more, more preferably 20°C / sec or more, even more preferably 30°C / sec or more, particularly preferably 50°C / sec or more, and most preferably 60°C / sec or more, from the viewpoint of suppressing stress relaxation during cooling. Furthermore, the cooling rate is preferably 200°C / sec or less, more preferably 180°C / sec or less, even more preferably 160°C / sec or less, particularly preferably 150°C / sec or less, and most preferably 140°C / sec or less, from the viewpoint of suppressing cracking during cooling.

[0069] When (B-2) is performed by bending, the cooling start temperature is preferably Tg + 40 ° C. or higher, more preferably Tg + 60 ° C. or higher, even more preferably Tg + 80 ° C. or higher, and particularly preferably Tg + 100 ° C. or higher, from the viewpoint of improving bending formability. Furthermore, the cooling start temperature is preferably Tg + 250 ° C. or lower, from the viewpoint of maintaining the shape of the glass after forming. Furthermore, it is preferably Tg + 230 ° C. or lower, more preferably Tg + 200 ° C. or lower, even more preferably Tg + 180 ° C. or lower, and particularly preferably Tg + 160 ° C. or lower. When (B-2) is performed by bending, the holding time is preferably 10 / (cooling start temperature - Tg) seconds or higher, more preferably 30 / (cooling start temperature - Tg) seconds or higher, even more preferably 60 / (cooling start temperature - Tg) seconds or higher, particularly preferably 120 / (cooling start temperature - Tg) seconds or higher, and most preferably 180 / (cooling start temperature - Tg) seconds or higher. Furthermore, for example, the cooling rate is preferably 600 / (cooling start temperature-Tg) seconds or less, more preferably 540 / (cooling start temperature-Tg) seconds or less, even more preferably 480 / (cooling start temperature-Tg) seconds or less, particularly preferably 420 / (cooling start temperature-Tg) seconds or less, and most preferably 360 / (cooling start temperature-Tg) seconds or less. When (B-2) is performed by bending, the cooling rate is preferably 1.0°C / sec or more, more preferably 10°C / sec or more, even more preferably 20°C / sec or more, particularly preferably 30°C / sec or more, and most preferably 60°C / sec or more, from the viewpoint of suppressing shape change after bending. Furthermore, from the viewpoint of suppressing cracking during cooling, the cooling rate is preferably 200°C / sec or less, more preferably 180°C / sec or less, even more preferably 160°C / sec or less, particularly preferably 150°C / sec or less, and most preferably 140°C / sec or less.

[0070] (Air-cooled tempering) The glass according to this embodiment may be air-cooled tempered glass (air-cooled tempered glass). The strength of the glass can be increased by performing an air-cooled tempering process. Air-cooled tempering is a process for forming a compressive stress layer on the surface of the glass by thermal tempering. Specifically, uniformly heated glass is rapidly cooled from a temperature near its softening point, and compressive stress is formed on the surface of the glass due to the temperature difference between the surface and the interior of the glass. The compressive stress is generated uniformly over the entire surface of the glass, and a compressive stress layer of uniform depth is formed over the entire surface of the glass. Thermal tempering is more suitable for tempering thick glass than chemical tempering.

[0071] The magnitude of the compressive stress on the surface of the glass (hereinafter also referred to as surface compressive stress CS) and the depth DOL of the compressive stress layer formed on the surface of the glass can be adjusted by the glass composition, the heat treatment temperature, and the cooling rate after the heat treatment, respectively.

[0072] When the glass according to the present embodiment is glass that has been subjected to air-cooling tempering, from the viewpoint of improving durability and strength, the surface compressive stress CS is preferably 30 MPa or more, more preferably 50 MPa or more, even more preferably 60 MPa or more, particularly preferably 70 MPa or more, and most preferably 80 MPa or more. Although there are no particular limitations on the upper limit of the surface compressive stress (CS), a high CS is balanced with a high internal tensile stress, and the higher the CS, the more energy is accumulated internally due to tensile stress, which means that the energy released upon fracture is large and dangerous. Therefore, the surface compressive stress CS is preferably 500 MPa or less, more preferably 300 MPa or less, even more preferably 200 MPa or less, particularly preferably 175 MPa or less, and most preferably 150 MPa or less.

[0073] When the glass according to this embodiment is glass that has been subjected to air-cooling tempering, from the viewpoint of improving durability and strength, the compressive stress layer depth DOL is preferably 0.15tmm or more, more preferably 0.16tmm or more, even more preferably 0.17tmm or more, particularly preferably 0.18tmm or more, and most preferably 0.19tmm or more, where t (unit: mm) is the thickness of the glass. Although the upper limit is not particularly limited, if the DOL is too deep, the thickness of the tensile stress layer becomes thin and it becomes difficult to balance with the compressive stress layer, so the DOL is preferably 0.35tmm or less, more preferably 0.33tmm or less, even more preferably 0.30tmm or less, particularly preferably 0.27tmm or less, and most preferably 0.25tmm or less.

[0074] (Bending) The glass according to the present embodiment may be glass that has been subjected to bending (bent glass). Examples of bent glass include bent glass obtained by forming flat glass into a curved shape by gravity forming, press forming, or the like.

[0075] The curved glass of this embodiment is glass that curves at a predetermined curvature, and may be single-curved glass that curves in only one direction, either up and down or left and right, or double-curved glass that curves in both up and down and left and right directions.

[0076] The minimum radius of curvature of the bent glass of this embodiment is preferably 50 mm or more and 100,000 mm or less. The radius of curvature of the bent glass is calculated by performing a shape simulation on a sample using a laser displacement meter (Dyvoce manufactured by Kohzu Seiki Co., Ltd.) based on the amount of warp inherent to the sample determined by weight deflection correction in a double-sided differential mode, and the radius of curvature is determined from the shape obtained by the simulation.

[0077] [Method of Manufacturing Bent Glass] In the method of manufacturing bent glass according to this embodiment, bent glass can be formed by heating and bending a sheet glass. Specifically, for example, a method is exemplified in which flat glass is heated, placed on a forming mold, and pressed from above by a press to bend it. Another example is a method in which flat glass is placed on a forming mold having a bending surface corresponding to the desired curved surface, and the forming mold is then carried into a heating furnace in this state, and the glass is heated in the heating furnace to a temperature close to the glass softening point. According to this forming method, the glass is curved by its own weight along the bending surface of the forming mold as it softens, thereby producing bent glass having the desired curved surface.

[0078] In this embodiment, bending by the press means is preferred from the viewpoint of improving productivity and improving surface accuracy after forming. The bending method by the press means is not particularly limited, and for example, the method described in International Publication No. 2016 / 093031 can be appropriately adopted. Hereinafter, the bending method by the press means will be described as an example.

[0079] First, the glass of this embodiment is transported to a press area by a transport conveyor or the like. Then, in the press area, the glass is heated to a temperature at which it can be bent and softened. Here, the bendable temperature is, for example, a temperature at which the glass viscosity is 10 １２ [dPa s] Temperature T １２ The heating may be performed by a heater in a heating furnace during the process of transporting the material to the pressing area on a transport conveyor or the like. １２ The bending time under the condition of maintaining the above condition can be set to, for example, 1 second or more.

[0080] A lower press mold (female mold) and an upper press mold (male mold) are arranged at predetermined positions in the press area, and the upper surface shape of the female mold and the lower surface shape of the male mold correspond to the curved shape of the glass to be bent in the conveying direction and the perpendicular direction. The female mold can be raised and lowered between a standby position below the conveyor and an upper press position. After the glass is transferred from the conveyor, the female mold, with the glass placed on it, is raised from a predetermined raised position to a press position above the conveyor, thereby press-forming the glass. The press-formed glass is then transported to the cooling area by a conveyor shuttle or the like. In the cooling area, the glass is cooled by blowing cooled air onto the glass, for example.

[0081] The above steps result in the formation of a curved glass. Although the above has been described with respect to the bending of glass according to the present embodiment, the bending may also be carried out in the form of laminated glass, which will be described later.

[0082] [Laminated Glass] The laminated glass according to this embodiment includes a first glass plate, a second glass plate, and an interlayer film sandwiched between the first glass plate and the second glass plate, and the first glass plate and / or the second glass plate is the glass according to this embodiment.

[0083] FIG. 1 is a diagram showing an example of a laminated glass 10 according to the present embodiment. The laminated glass 10 includes a first glass sheet 11, a second glass sheet 12, and an interlayer film 13 sandwiched between the first glass sheet 11 and the second glass sheet 12. The laminated glass 10 according to the present embodiment is not limited to the configuration shown in FIG. 1 and can be modified without departing from the spirit of the present invention. For example, the interlayer film 13 may be formed of a single layer as shown in FIG. 1 or may be formed of two or more layers. The laminated glass 10 according to the present embodiment may also include three or more glass sheets, in which case an organic resin or the like may be interposed between adjacent glass sheets. Hereinafter, the laminated glass 10 according to the present embodiment will be described as having only two glass sheets, a first glass sheet 11 and a second glass sheet 12, sandwiching the interlayer film 13.

[0084] In the laminated glass of the present embodiment, from the viewpoint of bend formability, the first glass sheet 11 and / or the second glass sheet 12 are preferably the glass of the present embodiment. When the first glass sheet 11 and the second glass sheet 12 are the glass of the present embodiment, the first glass sheet 11 and the second glass sheet 12 may be glass sheets having the same composition or different compositions.

[0085] In the laminated glass of this embodiment, when the first glass sheet 11 or the second glass sheet 12 is not the glass of this embodiment, the type of the glass sheet is not particularly limited, and any conventionally known glass sheet used for vehicle window glass, etc. can be used. Specific examples include alkali aluminosilicate glass, alkali aluminoborosilicate glass, and soda-lime glass. These glass sheets may or may not be colored to the extent that transparency is not impaired.

[0086] The thickness of the first glass sheet 11 is preferably 3.0 mm or more. Having a thickness of 3.0 mm or more of the first glass sheet 11 improves the durability of the laminated glass. The thickness of the first glass sheet 11 is more 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, even more preferably 3.5 mm or more, even more preferably 3.6 mm or more, particularly preferably 3.7 mm or more, and most preferably 3.8 mm or more. Furthermore, from the viewpoint of suppressing increases in fuel economy and electricity consumption due to an increase in the weight of the glass, the thickness of the first glass sheet 11 is preferably 10 mm or less, more preferably 9.0 mm or less, even more preferably 8.0 mm or less, even more preferably 7.0 mm or less, particularly preferably 6.0 mm or less, even more preferably 5.5 mm or less, even more preferably 5.0 mm or less, particularly preferably 4.8 mm or less, and most preferably 4.5 mm or less.

[0087] The thickness of the second glass plate 12 is preferably 1.1 mm or more, more preferably 1.2 mm or more, even more preferably 1.3 mm or more, particularly preferably 1.4 mm or more, particularly preferably 1.5 mm or more, and most preferably 1.6 mm or more. A thickness of 1.1 mm or more is preferable from the viewpoint of impact resistance. Furthermore, the thickness of the second glass plate 12 is preferably 3.0 mm or less, more preferably 2.8 mm or less, even more preferably 2.6 mm or less, particularly preferably 2.4 mm or less, particularly preferably 2.2 mm or less, and most preferably 2.0 mm or less. A thickness of 3.0 mm or less of the second glass plate 12 prevents the weight of the laminated glass 10 from becoming too large, which is preferable from the viewpoint of improving fuel efficiency when used in a vehicle.

[0088] Furthermore, the first glass plate 11 and the second glass plate 12 may have the same thickness or different thicknesses, but it is preferable that the first glass plate 11 be thicker than the second glass plate 12. That is, the relationship between the thickness t1 of the first glass plate 11 and the thickness t2 of the second glass plate 12 is preferably t1≧t2, and more preferably t1>t2.

[0089] Methods for adjusting the thickness of the first glass sheet 11 and the second glass sheet 12 include adjusting the thickness of the glass using a float method or a down-draw method, or polishing the glass in the thickness direction with a grinding stone and then polishing it to a mirror finish with an abrasive such as cerium oxide. 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.

[0090] In the laminated glass 10 of this embodiment, the thickness of the first glass sheet 11 and the second glass sheet 12 may be constant over the entire surface, or may vary from location to location as needed, such as forming a wedge shape in which the thickness of one or both of the first glass sheet 11 and the second glass sheet 12 gradually decreases.

[0091] The first glass plate 11 or the second glass plate 12 may be chemically strengthened glass that has been tempered to improve its strength. The chemical strengthening method is the same as the chemical strengthening method for glass described above. Examples of chemically strengthened glass include the alkali aluminosilicate glass and the alkali aluminoborosilicate glass that have been chemically strengthened.

[0092] The first glass sheet 11 and the second glass sheet 12 may have a flat shape or a curved shape having a curvature entirely or partially. If the first glass sheet 11 and the second glass sheet 12 are curved, they may have a single-curve shape, i.e., a curved shape in only one of the vertical or horizontal directions, or a complex-curve shape, i.e., a curved shape in both the vertical and horizontal directions. If the first glass sheet 11 and the second glass sheet 12 are curved, the radius of curvature in the vertical and horizontal directions may be the same or different. If the first glass sheet 11 and the second glass sheet 12 are curved, the radius of curvature in the vertical and / or horizontal directions is preferably 1000 mm or more. The shapes of the main surfaces of the first glass sheet 11 and the second glass sheet 12 are adapted to fit the window opening of the vehicle in which they are installed.

[0093] The interlayer film 13 is sandwiched between the first glass sheet 11 and the second glass sheet 12. By including the interlayer film 13, the laminated glass 10 of this embodiment can firmly bond the first glass sheet 11 and the second glass sheet 12 together and can also absorb the impact force when flying fragments collide with the glass sheets.

[0094] Various organic resins that are generally used in laminated glass for conventional vehicles can be used for the interlayer film 13. 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 formalin. Examples of materials that can be used include polyvinyl alcohol (PVF), polyvinyl alcohol (PVAL), vinyl acetate resin (PVAc), ionomer (IO), polymethylpentene (TPX), polyvinylidene chloride (PVDC), polysulfone (PSF), polyvinylidene fluoride (PVDF), methacrylic-styrene copolymer resin (MS), polyarate (PAR), polyallylsulfone (PASF), polybutadiene (BR), polyethersulfone (PESF), and polyetheretherketone (PEEK). Among these, EVA and PVB are preferred from the viewpoints of transparency and adhesion, and PVB is particularly preferred because it can impart sound insulation properties.

[0095] From the viewpoints of impact force absorption and sound insulation, the thickness of the interlayer film 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 suppressing a decrease in visible light transmittance, the thickness of the interlayer film 13 is preferably 1.00 mm or less, more preferably 0.900 mm or less, and even more preferably 0.800 mm or less. The thickness of the interlayer film 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.

[0096] The thickness of the intermediate film 13 may be constant over the entire surface, or may vary from place to place as required.

[0097] If the difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 is large, cracks or warping may occur in the laminated glass 10 when the laminated glass 10 is produced through the heating step described below, which may result in poor appearance. Therefore, it is preferable that the difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 is as small as possible. The difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 may be expressed as the difference between the average linear expansion coefficients within a predetermined temperature range.

[0098] In particular, since the resin constituting the interlayer film 13 has a low glass transition temperature, a predetermined difference in the average linear expansion coefficient may be set within a temperature range below the glass transition temperature of the resin material. The difference in the linear expansion coefficient between the first glass sheet 11 or the second glass sheet 12 and the resin material may be set at a predetermined temperature below the glass transition temperature of the resin material.

[0099] Alternatively, an adhesive layer containing an adhesive may be used for interlayer film 13. The adhesive is not particularly limited, but examples thereof include an acrylic adhesive, a silicone adhesive, etc. When interlayer film 13 is an adhesive layer, a heating step is not required in the process of joining first glass plate 11 and second glass plate 12, and therefore the risk of the above-mentioned cracking or warping occurring is reduced.

[0100] [Other Layers] The laminated glass 10 of the present embodiment may include layers (hereinafter also referred to as "other layers") other than the first glass sheet 11, the second glass sheet 12, and the interlayer film 13, provided that the effects of the present embodiment are not impaired. For example, the laminated glass 10 may include a coating layer that imparts water-repellent properties, hydrophilic properties, anti-fogging properties, or the like, an infrared reflective film, or the like.

[0101] The positions at which the other layers are provided are not particularly limited, and the other layers may be provided on the surface of the laminated glass 10, or may be sandwiched between the first glass sheet 11, the second glass sheet 12, or the interlayer film 13. The laminated glass 10 of this embodiment may also include a black ceramic layer or the like arranged in a strip shape along part or all of the peripheral edge for the purpose of concealing the attachment portion to the frame or the wiring conductors.

[0102] In the laminated glass of this embodiment, the total thickness of the first glass plate 11, the second glass plate 12, and the interlayer film 13 is preferably 4.4 mm or more. A total thickness of 4.4 mm or more can improve sound insulation. The total thickness is more preferably 4.8 mm or more, even more preferably 5.0 mm or more, even more preferably 5.1 mm or more, particularly preferably 5.2 mm or more, and most preferably 5.3 mm or more. From the viewpoint of weight reduction, the total thickness is preferably 14 mm or less, more preferably 12 mm or less, even more preferably 10 mm or less, particularly preferably 9.0 mm or less, particularly preferably 8.0 mm or less, and most preferably 7.0 mm or less. Note that if the total thickness of the first glass plate 11, the second glass plate 12, and the interlayer film 13 varies depending on the location, the total thickness at the thinnest location is preferably 4.4 mm or more.

[0103] The laminated glass of this embodiment has 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 １ / t ２ High durability can be achieved by the ratio (t １ / t ２ ) is more preferably 1.3 or more, even more preferably 1.5 or more, even more preferably 1.8 or more, even more preferably 2.0, still more preferably 2.2 or more, even more preferably 2.3 or more, particularly preferably 2.4 or more, and most preferably 2.5 or more. In addition, in order to approximate the curvature when the glass after bending is made into laminated glass, the ratio (t １ / t ２ ) is preferably 5.0 or less, more preferably 4.5 or less, even more preferably 4.0 or less, still more preferably 3.8 or less, especially preferably 3.5 or less, even more preferably 3.3 or less, even more preferably 3.2 or less, particularly preferably 3.1 or less, and most preferably 3.0 or less.

[0104] When the laminated glass 10 of this embodiment is used as a vehicle glass, the visible light transmittance Tv as defined in ISO-9050:2003 using a D65 light source is preferably 70% or more, more preferably 71% or more, and even more preferably 72% or more. Furthermore, Tv is, for example, 90% or less.

[0105] When used as vehicle glass, the laminated glass 10 of this embodiment preferably has a total solar transmittance (Tts) of 70% or less, as defined in ISO-13837:2008 Convention A and measured at a wind speed of 4 m / s. When the total solar transmittance (Tts) of the laminated glass 10 of this embodiment is 70% or less, sufficient heat-shielding properties are obtained. Tts is more preferably 68% or less, and even more preferably 66% or less. Furthermore, Tts is, for example, 55% or more.

[0106] The laminated glass 10 of this embodiment can be manufactured by a method similar to that of conventionally known laminated glass. For example, by laminating a first glass sheet 11, an interlayer film 13, and a second glass sheet 12 in this order and then subjecting them to a heating and pressurizing process, a laminated glass 10 is obtained in which the first glass sheet 11 and the second glass sheet 12 are bonded together via the interlayer film 13.

[0107] The method for manufacturing the laminated glass 10 of this embodiment may, for example, include a step of heating and shaping the first glass sheet 11 and the second glass sheet 12, followed by a step of inserting the interlayer film 13 between the first glass sheet 11 and the second glass sheet 12 and applying heat and pressure. By performing these steps, the laminated glass 10 may be configured such that the first glass sheet 11 and the second glass sheet 12 are joined together via the interlayer film 13.

[0108] [Uses] The glass of the present embodiment is for use in architecture, vehicles, or sensors, and more specifically, can be preferably used as window glass in architecture or vehicles or as cover glass for sensors. In particular, the glass of the present embodiment has excellent durability and formability, and is suitable for window glass in architecture or vehicles, specifically, for components such as windshields, side glass, rear glass, and roof glass. From the same viewpoint, the glass can be particularly suitable for use as cover glass for sensors such as LiDAR, cameras, and millimeter-wave radar mounted on vehicles or unmanned or manned eVTOLs (Electric Vertical Take-Off and Landing aircraft) such as drones.

[0109] An example of a specific application in which the glass of this embodiment is used as a window glass for a vehicle will be described below with reference to the drawings. Fig. 2 is a conceptual diagram showing a state in which a laminated glass 10 including the glass of this embodiment is installed in an opening 110 formed in the front of an automobile 100 and used as the window glass of the automobile. The laminated glass 10 used as the window glass of an automobile may have a housing (case) 120, which houses an information device or the like, attached to its surface on the interior side of the vehicle to ensure the driving safety of the vehicle.

[0110] The information device housed in the housing is a device that uses a camera, radar, etc. to prevent rear-end collisions with vehicles ahead, pedestrians, obstacles, etc., and to alert the driver to danger. For example, it is an information receiving device and / or information transmitting device, etc., and includes millimeter-wave radar, stereo cameras, infrared lasers, etc., which send and receive signals. The "signal" refers to electromagnetic waves including millimeter waves, visible light, infrared light, etc.

[0111] 3 is an enlarged view of the portion S in FIG. 2 and is a perspective view showing the portion of the laminated glass 10 of this embodiment where the housing 120 is attached. The housing 120 houses a millimeter-wave radar 201 and a stereo camera 202 as information devices. The housing 120 housing the information devices is usually attached on the outer side of the vehicle relative to the rearview mirror 150 and on the inner side of the vehicle relative to the laminated glass 10, but may also be attached to other portions.

[0112] 4 is a cross-sectional view taken along line Y-Y in FIG. 3 and perpendicular to the horizontal line. It is preferable that the first glass sheet 11 of the laminated glass 10 be disposed on the vehicle exterior side. This configuration allows for a lightweight windshield with excellent durability. Furthermore, because the glass of this embodiment has a low Young's modulus, it can be easily bent when manufacturing the windshield.

[0113] As described above, the present specification discloses the following configurations: 1. In terms of oxide mol %, SiO ２ : 65-80% B ２ O ３ :8.0~20% 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: 0.0-10% Na ２ O: 5.0-20% K ２ O: 0.0~10% Fe ２ O ３ Total iron oxide converted to: 0.004 to 1.0% R' ２ O: 5.0 to 20% RO: 0.0 to 5.0% (wherein RO is the total content of MgO, CaO, SrO and BaO, and R' ２ O is Li ２ O, Na ２ O and K ２1. A glass for architecture, vehicles or sensors, which contains 1,000,000 or more of fluorine-containing compounds (which is the total content of fluorine-containing compounds and fluorine-containing compounds), and which has a fictive temperature Tf of at least glass transition point +10°C and at least 500°C but not more than 750°C. 2. The glass according to 1 above, which has a fictive temperature Tf of less than 650°C. 3. The glass according to 1 above, which has a fictive temperature Tf of at least 650°C. 4. The glass according to any one of 1 to 3 above, which is curved glass. 5. The glass according to any one of 1 to 3 above, which is tempered glass. 6. The glass according to 5 above, which has a compressive stress (CS) of at least 30 MPa and a depth of compressive stress layer (DOL) of at least 0.2 × t (mm), where t represents the thickness (mm) of the tempered glass. 7. A laminated glass, which has a first glass sheet, a second glass sheet, and an interlayer sandwiched between the first glass sheet and the second glass sheet, and wherein the first glass sheet, the second glass sheet, or both are the glass according to any one of 1 to 6 above. 8. 9. The laminated glass according to 7 or 8 above, wherein the relationship between the thickness t1 of the first glass plate and the thickness t2 of the second glass plate satisfies t1≧t2. 10. The laminated glass according to 7 or 8 above, wherein the thickness t1 of the first glass plate is 3.0 mm or more, the thickness t2 of the second glass plate is 1.1 mm or more, and the sum of t1 and t2 (t1+t2) is 10 mm or less.

[0114] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0115] <Preparation of Glass Plate> Raw materials were placed in a platinum crucible and melted at a temperature of 1600°C to 1650°C for 3 hours to obtain molten glass so as to have the glass composition (unit: mol%) shown in Table 1. ２ O ３ " is Fe ２ O ３ The molten glass is poured onto a carbon plate and heated to a temperature above the glass transition temperature, T １１ The glass was maintained at the following temperature for 3 hours, and then slowly cooled at an average cooling rate of 1°C / min. Both surfaces of the obtained glass plate were polished to obtain a glass plate having a thickness of 3.1 mm. Examples 1 to 11 are working examples, and Examples 12 to 15 are comparative examples.

[0116] <Air-cooling tempering treatment> Glass sheets 3.1 mm thick and 45 mm square were heated in an electric furnace to 650°C (Examples 3, 6, 10, and 14) or 700°C (Examples 4, 7, 11, and 15). Immediately after the glass surface reached the target temperature, the glass sheets were removed from the electric furnace and cooled for 60 seconds at an air pressure of 3.4 kPa, thereby performing air-cooling tempering treatment. The heating time was 180 seconds.

[0117] The glass sheets obtained above were subjected to the following evaluations, and the results are shown in Table 1. Note that blank spaces in the table indicate that no measurement was performed. In Table 1, values ​​marked with "*" indicate values ​​before air-cooling and tempering treatment. For examples in which air-cooling and tempering treatment was performed, the results are shown for a glass sheet with a thickness of 3.1 mm that was subjected to air-cooling and tempering treatment.

[0118] (1) Glass transition temperature (T ｇ ): Values ​​measured using TMA and determined in accordance with JIS R3103-3 (2001).

[0119] (2) Fictitious temperature (Tf): Fictitious temperature T ｆ was determined by the following steps 1) to 3). 1) First, i (i≧2) test pieces were prepared from a glass sample whose fictive temperature was to be measured. Each test piece was placed in an electric furnace and held at a different cooling start temperature (550°C, 575°C, 600°C, 625°C, 650°C, 675°C, or 700°C) until the refractive index reached equilibrium. Thereafter, each test piece was removed from the electric furnace to the outside of the furnace at room temperature of 25°C, and cooled from the cooling start temperature at a cooling rate of 1000°C / min or more. 2) For the glass cooled under the conditions described in 1), the refractive index n ｄ The respective cooling start temperatures T ｉ The refractive index n of the glass rapidly cooled from the cooling start temperature ｄｉ 3) Next, the fictive temperature T ｆ The refractive index n of a test piece cut out from the glass to be measured and polished is ｄ The fictive temperature T of the glass is measured using a calibration curve. ｆ It was decided that:

[0120] (3) Temperature T １１Viscosity η, which is the standard for glass bending workability, is 10 １１ Temperature T when viscosity becomes dPa s １１ was measured using the beam bending method.

[0121] (4) Average coefficient of linear expansion (CTE) from 50 to 350 °C ５０－３５０ ): Measured using a differential thermal dilatometer (TMA) and determined in accordance with JIS R3102 (1995).

[0122] (5) Density: A glass block of about 20 g containing no bubbles cut out from a glass plate was measured by Archimedes' method.

[0123] (6) Young's modulus: Measured at 25° C. by an ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0124] (7) Rigidity Modulus: Measured at 25° C. by an ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Testing Method for Elastic Modulus of Fine Ceramics."

[0125] (8) Poisson's ratio: Measured at 25° C. by an ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0126] (9) Compressive stress CS and compressive stress layer depth DOL The compressive stress CS and compressive stress layer depth DOL were measured using a scattered light photoelastic stress meter SLP-2000 and a glass surface stress meter FSM manufactured by Orihara Seisakusho.

[0127]

[0128] The glasses of Examples 1 to 7, which are working examples, have Young's modulus and CTE values ​​lower than those of Example 12, which is a comparative example. ５０－３５０ Comparative Example 12 has an RO of more than 5.0% and a CTE of ５０－３５０ The glasses of Examples 8 to 11, which are working examples, had a higher CTE than the glasses of Examples 13 to 15, which are comparative examples. ５０－３５０ In Examples 13 to 15, which are comparative examples, R' ２ O is less than 5.0%, and CTE ５０－３５０was big.

[0129] <Preparation of Laminated Glass> Laminated glasses of Test Examples 1 to 5 were prepared according to the following procedure. Test Examples 1 to 5 are examples.

[0130] (Test Example 1) A glass having a thickness of 3.0 mm and a composition shown in Example 4 in Table 1 was used as the first glass plate. A polyvinyl butyral (PVB) having a thickness of 0.78 mm was used as the interlayer film. A glass having a thickness of 1.1 mm and a composition shown in Example 1 in Table 1 was used as the second glass plate. The first glass plate, the interlayer film, and the second glass plate were laminated in this order, and after preliminary bonding at 120°C for 15 minutes, pressure bonding was performed under conditions of 130°C and 1 MPa. The laminated glass of Test Example 1 was then produced by returning to room temperature and atmospheric pressure over 90 minutes. The laminated glass of Test Example 1 had a total thickness of 4.9 mm for the first glass plate, the second glass plate, and the interlayer film, and a thickness of t １ and the thickness t of the second glass plate ２ The ratio (t １ / t ２ ) was 2.7.

[0131] Test Examples 2 to 5 Laminated glasses were produced in the same manner as in Test Example 1, except that the types of the first glass plate and the second glass plate were changed to those shown in Table 2.

[0132]

[0133] 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 can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2023-221646) filed on December 27, 2023, the entirety of which is incorporated by reference. All references cited herein are incorporated in their entirety.

[0134] REFERENCE SIGNS LIST 10 Laminated glass 11 First glass sheet 12 Second glass sheet 13 Interlayer 100 Automobile 110 Opening 120 Housing 150 Rearview mirror 201 Millimeter wave radar 202 Stereo camera 300 Radio wave

Claims

1. In terms of molar percentage based on oxides, SiO ２ : 65 - 80%, B ２ O ３ : 8.0 - 20%, 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: 0.0 - 10%, Na ２ O: 5.0 - 20%, K ２ O: 0.0 - 10%, total iron oxide converted to Fe ２ O ３ : 0.004 - 1.0%, R' ２ O: 5.0 - 20%, RO: 0.0 - 5.0% (where RO is the total content of MgO, CaO, SrO and BaO, and R' ２ O is the total content of Li ２ O, Na ２ O and K ２ O), and the fictive temperature Tf is 10°C or more above the glass transition point and 500°C or more and 750°C or less, a glass for architecture, vehicles or sensors.

2. The glass according to claim 1, wherein the fictive temperature Tf is less than 650°C.

3. The glass according to claim 1, wherein the fictive temperature Tf is 650°C or higher.

4. The glass according to any one of claims 1 to 3, which is bent glass.

5. The glass according to any one of claims 1 to 3, which is air-cooled tempered glass.

6. The glass according to claim 5, satisfying a compressive stress (CS) of 30 MPa or more and a depth of the compressive stress layer (DOL) of 0.2 × t (mm) or more. Here, t represents the thickness (mm) of the air-cooled tempered glass.

7. A laminated glass having a first glass plate, a second glass plate, and an intermediate film sandwiched between the first glass plate and the second glass plate, wherein the first glass plate, the second glass plate, or both are the glass according to any one of claims 1 to 6.

8. The laminated glass according to claim 7, wherein the relationship between the plate thickness t1 of the first glass plate and the plate thickness t2 of the second glass plate is t1 ≧ t2.

9. The laminated glass according to claim 7 or 8, wherein the plate thickness t1 of the first glass plate is 3.0 mm or more, the plate thickness t2 of the second glass plate is 1.1 mm or more, and the sum t1 + t2 of t1 and t2 is 10 mm or less.

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