Alkali-free glass and glass plates

Abstract

A purpose of the present invention is to provide an alkali-free glass which has a low dielectric loss tangent in a high-frequency region and is excellent in terms of acid resistance, moisture resistance, and phase separation property. The present invention relates to an alkali-free glass comprising, in terms of oxide amount in mol%, 50-76 SiO2, 2-6 Al2O3, 18-35 B2O3, 1-6 MgO, 0.5-5 CaO, 1-5 SrO, and 0-3 BaO and having a value of expression (A) of 3.5-6, a value of expression (B) of -2 to 2, a value of expression (J) of 0.2-0.7, and a value of Δβ-OH of 0 mm-1 to 0.1 mm-1.

Description

[Technical Field]

[0001] This invention relates to alkali-free glass. The invention also relates to glass plates containing such alkali-free glass, glass substrates for high-frequency devices, panel antennas, window glass, vehicle window glass, and cover glass for touch panels. [Background technology]

[0002] Examples of electronic devices include communication equipment such as mobile phones, smartphones, personal digital assistants (PDAs), and Wi-Fi devices, as well as surface acoustic wave (SAW) devices, radar components, and antenna components. In such electronic devices, the signal frequency is being increased to achieve higher communication capacities and faster communication speeds. Circuit boards used in high-frequency electronic equipment generally use insulating substrates such as resin substrates, ceramic substrates, and glass substrates. Insulating substrates used in high-frequency devices are required to reduce transmission losses due to dielectric loss and conductor loss in order to ensure the quality and strength of high-frequency signals.

[0003] Of these insulating substrates, resin substrates have low rigidity due to their properties. Therefore, resin substrates are difficult to apply when rigidity (strength) is required for semiconductor packaging products. Ceramic substrates have the drawback that it is difficult to improve surface smoothness, which tends to increase conductor loss due to conductors formed on the substrate surface. On the other hand, glass substrates have high rigidity, making it easy to miniaturize and thin packages, and they also have excellent surface smoothness and can be easily enlarged as substrates themselves.

[0004] Patent Document 1 discloses a glass substrate for high-frequency devices having a dielectric loss tangent of 0.007 or less at a frequency of 35 GHz. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2018 / 051793 [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, in addition to reducing the dielectric loss tangent in the high-frequency range, glass substrates for the above applications are required to have excellent acid resistance. In the manufacturing process of circuit boards such as liquid crystal antennas and high-frequency devices, chemical cleaning is performed as a pretreatment before forming a wiring layer on the glass substrate. If the chemical resistance of the glass is low, for example, during acid cleaning, the substrate surface may dissolve, impairing the smoothness of the substrate surface, which may reduce the adhesion of the film formed on the substrate surface. In addition, there is a risk that eluted substances may adhere to the substrate surface. This may lead to increased conductor loss caused by the conductors formed on the substrate surface.

[0007] Furthermore, glass substrates for the above applications are required to have excellent moisture resistance. If moisture resistance is low, the substrate surface may deteriorate during storage, potentially impairing its smoothness. Excellent moisture resistance also allows the substrate to withstand use under high humidity conditions.

[0008] Furthermore, glass substrates for the above applications are required to have excellent phase separation characteristics. If the glass has excellent phase separation characteristics, for example, localized irregularities on the substrate surface can be effectively prevented when the glass substrate is acid-cleaned. This reduces the transmission loss of high-frequency signals.

[0009] The present invention aims to provide alkali-free glass that exhibits low dielectric loss tangent in the high-frequency range and excellent acid resistance, moisture resistance, and phase separation characteristics. [Means for solving the problem]

[0010] The inventors of the present invention have found that by specifying a particular composition range for the glass, and in particular by reducing the proportion of three-coordinate boron in the boron contained in the glass, moisture resistance can be improved while maintaining good dielectric loss and acid resistance, thereby solving the above problems, and have completed the present invention. [1] Expressed in mole percent based on oxides SiO250~76, Al2O32~6, B2O318~35, MgO 1-3.5 CaO 0.5~4, SrO 1~4.5, It contains BaO 0-3, Equation (A) is [MgO]+[CaO]+[SrO]+[BaO], and the value of equation (A) is between 3.5 and 6. Equation (B) is [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]), and the value of equation (B) is between -2 and 2. Equation (J) is ([MgO]+[CaO]) / ([MgO]+[CaO]+[SrO]+[BaO]), and the value of the above equation (J) is 0.2 to 0.7. The Δβ-OH calculated by the method below is 0 mm -1 ~0.1mm -1 It is alkali-free glass. Method: The β-OH of a 1.0 mm thick glass plate made of alkali-free glass was measured, and then the glass plate was left to stand at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate was measured 90 hours after the start of standing. The value obtained by subtracting the β-OH before standing from the β-OH after standing was calculated as Δβ-OH. [2] expressed in mole percent based on oxides SiO250~67, Al2O32~6, B2O318~35, MgO 1~5.5 CaO 0-4.5 SrO 0.5~5, It contains BaO 0-3, Equation (A) is [MgO]+[CaO]+[SrO]+[BaO], and the value of equation (A) is between 3.5 and 6. Equation (B) is [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]), and the value of equation (B) is between -2 and 2. Equation (K) is [SiO2] / ([SiO2]+[B2O3]), and the value of the above equation (K) is 0.59 to 0.7. Equation (L) is 119-(106×[SiO2]+60×[Al2O3]+119×[B2O3]+37×[MgO]+32×[CaO]+32×[SrO]+33×[BaO]+36×[Li2O]+20×[Na2O]+13×[K2O]), and the value of the above equation (L) is 16 to 30. The Δβ-OH calculated by the method below is 0 mm -1 ~0.1mm -1 It is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing. [3] expressed in mole percent based on oxides SiO250~68, Al2O32~6, B2O326.5~35, MgO 1-5, CaO 0-5, SrO 1-5, It contains BaO 0-3, Equation (A) is [MgO]+[CaO]+[SrO]+[BaO], and the value of equation (A) is between 2 and 6. Equation (B) is [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]), and the value of equation (B) is between -3 and 2. The amount of three-coordinate boron contained in the glass is 0 to 26 when expressed as B2O3 in mole percent based on oxides. The Δβ-OH calculated by the method below is 0 mm -1 ~0.1mm -1 It is alkali-free glass. Method: After measuring the β-OH of a glass plate made of alkali-free glass with a thickness of 1.0 mm, the glass plate is left standing at a temperature of 60 °C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. The value obtained by subtracting the β-OH before standing from the β-OH after standing is calculated as Δβ-OH. [4] The alkali-free glass according to any one of [1] to [3], having an ultraviolet transmittance of 2% or more measured under the following conditions. Conditions: A glass plate with a thickness of 2.0 mm is heated to a temperature T4 (°C) at which the glass viscosity becomes 10 4 dPa·s, slowly cooled to room temperature at 40 °C / min, and then the parallel light transmittance of the glass plate with both sides mirror-finished to a thickness of 1.3 mm is measured at a wavelength of 308 nm. [5] The alkali-free glass according to any one of [1] to [4], having a dielectric loss tangent at a frequency of 35 GHz of 0.005 or less. [6] Density is 2.58 g / cm 3 Hereinafter, the average thermal expansion coefficient at 50 to 350 °C is 20 × 10 -7 / °C to 50 × 10 -7 / °C, the alkali-free glass according to any one of [1] to [5]. [7] The temperature T2 at which the glass viscosity becomes 10 2 dPa·s is 1500 to 1900 °C, and the temperature T4 at which the glass viscosity becomes 10 4 dPa·s is 1400 °C or lower, the alkali-free glass according to any one of [1] to [6]. [8] The alkali-free glass according to any one of [1] to [7], having a glass transition temperature of 700 °C or lower. [9] The alkali-free glass according to any one of [1] to [8], having a surface devitrification temperature of 1400 °C or lower.

[10] A glass plate containing the alkali-free glass according to any one of [1] to [9], having a main surface and an end face, and at least one main surface having an arithmetic mean roughness Ra of 1.5 nm or less.

[11] A glass plate containing the alkali-free glass according to any one of [1] to

[10] , having a main surface and an end face, and having at least one side of 1000 mm or more and a thickness of 0.7 mm or less. A method for manufacturing a glass plate, in which alkali-free glass described in any one of

[12] [1] to [9] is produced by the float method or the fusion method. A method for manufacturing a glass plate containing alkali-free glass as described in any one of

[13] [1] to [9], To obtain molten glass by heating glass raw materials, Removing bubbles from molten glass, To obtain a glass ribbon by forming molten glass into a plate, and The glass ribbon is slowly cooled to room temperature. Includes, The aforementioned slow cooling is a method for manufacturing a glass plate, wherein the glass ribbon is slowly cooled so that its equivalent cooling rate is 800°C / min or less.

[14] expressed in mole percent based on oxides SiO258~70, Al2O3 4.5~8 B2O318~28, MgO 0.5~5, CaO 0.1~3, SrO 0.1~3, It contains BaO 0-3, Equation (A) is [MgO]+[CaO]+[SrO]+[BaO], and the value of equation (A) is between 3.5 and 8. Equation (B) is [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]), and the value of equation (B) is between 0 and 3. Equation (C) is [SiO2] + [B2O3], and the value of the above equation (C) is 87 to 95. Equation (E) is [MgO] / ([MgO]+[CaO]+[SrO]+[BaO]), and the value of the above equation (E) is between 0.5 and 1. The Δβ-OH calculated by the method below is 0 mm -1 ~0.1mm -1 It is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing. [Effects of the Invention]

[0011] The alkali-free glass of the present invention has a low dielectric loss tangent in the high-frequency range. Therefore, it can reduce dielectric loss of high-frequency signals and is suitable for glass substrates for high-frequency devices. Circuit boards using such glass substrates can reduce transmission loss of high-frequency signals and provide practical high-frequency devices such as electronic devices. The alkali-free glass of the present invention exhibits excellent acid resistance. Therefore, when glass substrates are acid-cleaned during the manufacturing process of circuit boards such as liquid crystal antennas and high-frequency devices, there is no risk of the substrate surface dissolving, deteriorating the smoothness of the substrate surface, or of leached substances adhering to the substrate surface. This prevents a decrease in the adhesion of films formed on the substrate surface. Furthermore, it prevents an increase in conductor loss. The alkali-free glass of the present invention can reduce the transmission loss of radio waves in the high frequency band. Therefore, it is suitable for glass products that transmit and receive radio waves in the high frequency band. The alkali-free glass of this invention has excellent moisture resistance. Therefore, it can prevent deterioration during storage. Furthermore, it is suitable for use under high temperature and high humidity conditions. The alkali-free glass of the present invention exhibits excellent phase separation characteristics. Therefore, for example, it can effectively prevent localized irregularities from forming on the substrate surface when a glass substrate is acid-cleaned. This reduces the transmission loss of high-frequency signals. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of the configuration of a circuit board for high-frequency devices. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below. This invention contains SiO2 50-76, Al2O3 2-6, B2O3 18-35, MgO 1-3.5, CaO 0.5-4, SrO 1-4.5, and BaO 0-3 in molar percentages based on oxides, with a value of 3.5-6 for formula (A), a value of -2-2 for formula (B), a value of 0.2-0.7 for formula (J), and Δβ-OH 0 mm -1 ~0.1mm -1 The present invention provides alkali-free glass (hereinafter referred to as "glass of the first embodiment").

[0014] Furthermore, the present invention contains SiO2 50-67, Al2O3 2-6, B2O3 18-35, MgO 1-5.5, CaO 0-4.5, SrO 0.5-5, and BaO 0-3 in molar percentages based on oxides, with a value of 3.5-6 for formula (A), a value of -2-2 for formula (B), a value of 0.59-0.7 for formula (K), a value of 16-30 for formula (L), and Δβ-OH 0 mm -1 ~0.1mm -1 The present invention provides alkali-free glass (hereinafter referred to as "glass of the second embodiment").

[0015] Furthermore, the present invention contains SiO2 50-68, Al2O3 2-6, B2O3 26.5-35, MgO 1-5, CaO 0-5, SrO 1-5, and BaO 0-3 in molar percentages based on oxides, with a value of 2-6 for formula (A), a value of -3-2 for formula (B), 3-coordinate boron contained in the glass being 0-26 in terms of B2O3, and Δβ-OH being 0 mm -1 ~0.1mm -1 The present invention provides alkali-free glass (hereinafter referred to as "glass of the third embodiment").

[0016] Furthermore, the present invention contains SiO2 58-70, Al2O3 4.5-8, B2O3 18-28, MgO 0.5-5, CaO 0.1-3, SrO 0.1-3, and BaO 0-3 in molar percentages based on oxides, with a value of 3.5-8 for formula (A), 0-3 for formula (B), 87-95 for formula (C), 0.5-1 for formula (E), and 0 mm³ of Δβ-OH. -1 ~0.1mm -1The present invention provides alkali-free glass (hereinafter referred to as "glass of the fourth embodiment"). In this specification, "the glass of the present invention" includes the glass of the first embodiment, the glass of the second embodiment, the glass of the third embodiment, and the glass of the fourth embodiment.

[0017] In the following explanation, numerical ranges indicated using "~" represent the range that includes the numbers before and after "~" as the minimum and maximum values, respectively. Unless otherwise specified, the content of each component in alkali-free glass and glass plates is given as mole percentage (mol%) based on the oxide. Also, the notation "[metal oxide]" in formulas (A) to (R) represents the mole percentage of the metal oxide component. For example, [MgO] represents the mole percentage of magnesium oxide. In this specification, "high frequency" refers to a frequency of 10 GHz or higher, preferably greater than 30 GHz, more preferably 35 GHz or higher. It is also defined as 3 THz or lower, preferably 1 THz or lower, more preferably 300 GHz or lower, and even more preferably 100 GHz or lower.

[0018] The glass of the present invention (hereinafter sometimes simply referred to as "glass") will be described below.

[0019] The glass of the first embodiment contains 50-76% SiO2. The glass of the second embodiment contains 50-67% SiO2. The glass of the third embodiment contains 50-68% SiO2. The glass of the fourth embodiment contains 58-70% SiO2. SiO2 is a network-forming material, and if the SiO2 content is 50 mol% (hereinafter simply referred to as %) or more, the dielectric loss tangent in the high-frequency range can be reduced, the glass-forming ability and acid resistance can be improved, and the rise in surface devitrification temperature can be suppressed. In the glass of the first to third embodiments, the SiO2 content is preferably 55% or more, more preferably 58% or more, even more preferably 60% or more, even more preferably 60.5% or more, and especially preferably 61% or more. In the glass of the fourth embodiment, the SiO2 content is preferably 59% or more, more preferably 60% or more, even more preferably 61% or more, even more preferably 61.5% or more, and especially preferably 62% or more. Furthermore, in the glass of the first embodiment, if the SiO2 content is 76% or less, the solubility of the glass can be improved. In the glass of the first embodiment, the SiO2 content is preferably 72% or less, more preferably 70% or less, even more preferably 69% or less, even more preferably 68% or less, especially preferably 67% or less, even more preferably 66% or less, even more preferably 65% ​​or less, even more preferably 64% or less, even more preferably 63.5% or less, even more preferably 63% or less, especially more preferably 62.5% or less, and even more preferably 62% or less. In the glass of the second embodiment, the solubility of the glass can be improved if the SiO2 content is 67% or less. In the glass of the second embodiment, the SiO2 content is preferably 66% or less, more preferably 65% ​​or less, even more preferably 64% or less, even more preferably 63.5% or less, especially preferably 63% or less, even more preferably 62.5% or less, and even more preferably 62% or less. In the glass of the third embodiment, the solubility of the glass can be improved if the SiO2 content is 68% or less. In the glass of the third embodiment, the SiO2 content is preferably 67% or less, more preferably 66% or less, even more preferably 65% ​​or less, even more preferably 64.5% or less, especially preferably 64% or less, even more preferably 63.5% or less, and even more preferably 63% or less. In the glass of the fourth embodiment, the solubility of the glass can be improved if the SiO2 content is 70% or less. In the glass of the fourth embodiment, the SiO2 content is preferably 69% or less, then more preferably 68% or less, 67% or less, 66% or less, more preferably 65% ​​or less, even more preferably 64% or less, even more preferably 63.5% or less, especially preferably 63% or less, even more preferably 62.5% or less, and even more preferably 62% or less.

[0020] The glass of the first to third embodiments contains 2-6% Al2O3. The glass of the fourth embodiment contains 4-8% Al2O3. Al2O3 is a component that is effective in improving acid resistance, improving Young's modulus, improving the phase separation characteristics of the glass, and lowering the coefficient of thermal expansion. In the glass of the first to third embodiments, if the Al2O3 content is 2% or more, the acid resistance and phase separation properties of the glass are improved. In the glass of the first to third embodiments, the Al2O3 content is preferably 3% or more, more preferably 3.5% or more, even more preferably 4% or more, even more preferably 4.2% or more, and especially preferably 4.5% or more. In the glass of the fourth embodiment, if the Al2O3 content is 4% or more, the acid resistance and phase separation properties of the glass are improved. In the glass of the fourth embodiment, the Al2O3 content is preferably 4.2% or more, more preferably 4.5% or more, even more preferably 4.8% or more, even more preferably 5% or more, and especially preferably 5.2% or more. Furthermore, in the glass of the first to third embodiments, if the Al2O3 content is 6% or less, the dielectric loss tangent in the high-frequency range can be reduced. The Al2O3 content is preferably 5.8% or less, more preferably 5.6% or less, even more preferably 5.4% or less, even more preferably 5.2% or less, and especially preferably 5% or less. In the glass of the fourth embodiment, if the Al2O3 content is 8% or less, the dielectric loss tangent in the high-frequency range can be reduced. In the glass of the fourth embodiment, the Al2O3 content is preferably 7.5% or less, more preferably 7% or less, even more preferably 6.5% or less, even more preferably 6% or less, and especially preferably 5% or less.

[0021] The glass of the first and second embodiments contains 18-35% B2O3. The glass of the third embodiment contains 26.5-35% B2O3. The glass of the fourth embodiment contains 18-28% B2O3. In the glass of the first and second embodiments, solubility is improved if the B2O3 content is 18% or more. In addition, the dielectric loss tangent in the high-frequency range can be reduced. In the glass of the first and second embodiments, the B2O3 content is preferably 20% or more, more preferably 22% or more, even more preferably 23% or more, even more preferably 24% or more, especially preferably 25% or more, even more preferably 26% or more, even more preferably 26.5% or more, even more preferably 27% or more, even more preferably 27.2% or more, and even more preferably 27.5% or more. In the glass of the third embodiment, solubility is improved if the B2O3 content is 26.5% or more. In addition, the dielectric loss tangent in the high-frequency range can be reduced. In the glass of the third embodiment, the B2O3 content is preferably 26.6% or more, more preferably 26.8% or more, and particularly preferably 27% or more. In the glass of the fourth embodiment, if the B2O3 content is 18% or more, the solubility is improved. In addition, the dielectric loss tangent in the high-frequency range can be reduced. In the glass of the fourth embodiment, the B2O3 content is preferably 20% or more, more preferably 21% or more, even more preferably 22% or more, even more preferably 23% or more, and especially preferably 24% or more. Furthermore, in the glass of the first to third embodiments, acid resistance can be improved if the B2O3 content is 35% or less. The B2O3 content is preferably 33% or less, more preferably 31% or less, even more preferably 30% or less, even more preferably 29.5% or less, especially preferably 29% or less, and still even more preferably 28.5% or less. In the glass of the fourth embodiment, acid resistance can be improved if the B2O3 content is 28% or less. The B2O3 content is preferably 27.5% or less, more preferably 27.2% or less, even more preferably 27% or less, even more preferably 26.8% or less, especially preferably 26.5% or less, and still even more preferably 26% or less.

[0022] Boron ions in this glass can have oxygen coordination numbers of 3 or 4. In typical boron-containing alkali-free glass, the oxygen coordination number of boron is mainly 3. 4-coordinate boron (hereinafter referred to as B [4] (sometimes referred to as) enters the glass framework and takes on a tetrahedral structure, making it less reactive with water and improving moisture resistance. On the other hand, tri-coordinate boron (hereinafter referred to as B) [3] (Sometimes referred to as) reduces the moisture resistance of glass. In the glass of the present invention, the ratio of the amount of 3-coordinate boron to the total amount of 3-coordinate boron and 4-coordinate boron contained in the glass is preferably 0.5 to 0.98. If the ratio of the amount of 3-coordinate boron to the total amount of 3-coordinate boron and 4-coordinate boron is 0.5 or higher, acid resistance can be increased. The ratio of the amount of 3-coordinate boron to the total amount of 3-coordinate boron and 4-coordinate boron is more preferably 0.7 or higher, even more preferably 0.8 or higher, particularly preferably 0.9 or higher, still still preferably 0.92 or higher, and particularly preferably 0.94 or higher. Furthermore, if the ratio of the amount of 3-coordinate boron to the total amount of 3-coordinate boron and 4-coordinate boron is 0.98 or lower, dielectric properties can be maintained well. Moisture resistance can be improved. A value of 0.97 or less is preferred, 0.965 or less is more preferred, 0.96 or less is even more preferred, 0.955 or less is particularly preferred, and 0.95 or less is even more preferred.

[0023] Furthermore, in the third embodiment, from the viewpoint of improving moisture resistance, the content of tri-coordinate boron contained in the glass is 26% or less in terms of B2O3. In the third embodiment, the tri-coordinate boron content is preferably 25.8% or less, more preferably 25.6% or less, even more preferably 25.4% or less, and even more preferably 25.2% or less. Also, in the third embodiment, from the viewpoint of acid resistance, the tri-coordinate boron content is 0% or more in terms of B2O3. In the third embodiment, the tri-coordinate boron content is more preferably 5% or more, even more preferably 10% or more, even more preferably 15% or more, especially preferably 20% or more, and even more preferably 22% or more.

[0024] The ratio of the amounts of 3-coordinate boron and 4-coordinate boron is,11 It is measured by 1B-NMR. Methods for adjusting the ratio of 3-coordinate boron to the total amount of 3-coordinate boron and 4-coordinate boron include, for example, adjusting the composition and cooling conditions. Specifically, for example, as a method for adjusting the composition, methods include adjusting formula (L), a parameter representing the basicity of the oxide, to preferably be between 16 and 30; adjusting formula (J), a ratio of alkaline earth metals, to be between 0.2 and 0.7; and adjusting formula (M), a parameter representing the cation strength, to be between 1.5 and 2.5. Also, for example, as a method for adjusting the cooling conditions, methods include preferably setting the equivalent cooling rate in the slow cooling process of glass manufacturing to 800°C / min or less.

[0025] In the glass of this invention, MgO is a component that increases Young's modulus without increasing specific gravity. In other words, MgO is a component that increases the specific modulus of elasticity, thereby reducing the problem of deflection, improving fracture toughness, and increasing the strength of the glass. Furthermore, MgO is a component that also improves solubility. The glass of the first embodiment contains 1-3.5% MgO. The glass of the second embodiment contains 1-5.5% MgO. The glass of the third embodiment contains 1-5% MgO. The glass of the fourth embodiment contains 0.5-5% MgO. In the glass of the first to third embodiments, the effect of including MgO is obtained if the MgO content is 1% or more. In the glass of the first to third embodiments, the MgO content is preferably 1.2% or more, more preferably 1.4% or more, even more preferably 1.6% or more, even more preferably 1.8% or more, and particularly preferably 2% or more. In the glass of the fourth embodiment, the effect of including MgO is obtained if the MgO content is 0.5% or more. In the glass of the fourth embodiment, the MgO content is preferably 1% or more, more preferably 1.2% or more, even more preferably 1.5% or more, even more preferably 1.7% or more, and particularly preferably 2% or more. In the glass of the first embodiment, if the MgO content is 3.5% or less, the rise in surface devitrification temperature is suppressed, and the deterioration of moisture resistance is also easily suppressed. For this reason, the MgO content is 3.5% or less, preferably 3.2% or less, more preferably 3% or more, even more preferably 2.8% or more, and even more preferably 2.5% or more. In the glass of the second embodiment, if the MgO content is 5.5% or less, the rise in surface devitrification temperature is suppressed, and the deterioration of moisture resistance is also easily suppressed. For this reason, the MgO content is preferably 5% or less, more preferably 4% or less, even more preferably 3.5% or less, and even more preferably 3% or less. In the glass of the third and fourth embodiments, if the MgO content is 5% or less, the rise in surface devitrification temperature is suppressed, and the deterioration of moisture resistance is also easily suppressed. For this reason, the MgO content is preferably 4.5% or less, more preferably 4% or less, even more preferably 3.5% or less, and even more preferably 3% or less.

[0026] In the glass of the present invention, CaO has the characteristics of having the second highest specific modulus among alkaline earth metals, after MgO, and not excessively lowering the strain point, and like MgO, it is a component that also improves solubility. Furthermore, it is a component that has the characteristics of not worsening moisture resistance and not raising the surface devitrification temperature as much as MgO.

[0027] The glass of the first embodiment contains 0.5 to 4% CaO. The glass of the second embodiment contains 0 to 4.5% CaO. The glass of the third embodiment preferably contains 0 to 5% CaO. The glass of the fourth embodiment contains 0.1 to 3% CaO. In the glass of the first embodiment, if the CaO content is 4% or less, the average thermal expansion coefficient does not become too high, and the rise in surface devitrification temperature can be suppressed. In the glass of the first embodiment, the CaO content is preferably 3.8% or less, more preferably 3.5% or less, even more preferably 3.2% or less, even more preferably 3% or less, especially preferably 2.8% or less, even more preferably 2.5% or less, even more preferably 2.2% or less, and even more preferably 2% or less. In the glass of the second embodiment, if the CaO content is 4.5% or less, the average thermal expansion coefficient does not become too high, and the rise in surface devitrification temperature can be suppressed. In the glass of the second embodiment, the CaO content is preferably 4% or less, more preferably 3.5% or less, even more preferably 3.2% or less, even more preferably 3% or less, especially preferably 2.8% or less, even more preferably 2.5% or less, even more preferably 2.2% or less, and even more preferably 2% or less. In the glass of the third embodiment, if the CaO content is 5% or less, the average coefficient of thermal expansion does not become too high, and the rise in surface devitrification temperature can be suppressed. In the glass of the third embodiment, the CaO content is preferably 4.5% or less, more preferably 4% or less, even more preferably 3.5% or less, even more preferably 3% or less, especially preferably 2.8% or less, even more preferably 2.5% or less, even more preferably 2.2% or less, and even more preferably 2% or less. In the glass of the fourth embodiment, if the CaO content is 3% or less, the average thermal expansion coefficient does not become too high, and the rise in surface devitrification temperature can be suppressed. In the glass of the fourth embodiment, the CaO content is preferably 2.8% or less, more preferably 2.5% or less, even more preferably 2.2% or less, and even more preferably 2% or less. In the glass of the first embodiment, the above-mentioned effects can be sufficiently obtained if the CaO content is 0.5% or more. Therefore, the CaO content is 0.5% or more, preferably 0.6% or more, more preferably 0.7% or more, even more preferably 0.8% or more, even more preferably 0.9% or more, and even more preferably 1% or more. In the glass of the second and third embodiments, if CaO is contained, the content is preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, especially preferably 0.6% or more, even more preferably 0.7% or more, even more preferably 0.8% or more, even more preferably 0.9% or more, and especially especially more preferably 1% or more. In the glass of the fourth embodiment, the above-mentioned effects can be sufficiently obtained if the CaO content is 0.1% or more. Therefore, the CaO content is 0.1% or more, preferably 0.2% or more, more preferably 0.5% or more, even more preferably 0.6% or more, especially preferably 0.7% or more, even more preferably 0.8% or more, even more preferably 0.9% or more, even more preferably 1% or more, and especially even more preferably 1.5% or more.

[0028] The glass of the first embodiment contains 1-4.5% SrO. The glass of the second embodiment contains 0.5-5% SrO. The glass of the third embodiment contains 1-5% SrO. The glass of the fourth embodiment contains 0.1-3% SrO. SrO is a component that enhances the moisture resistance of the glass, does not raise the surface devitrification temperature, and improves solubility. In the glass of the first and third embodiments, the above-mentioned effects are easily obtained if the SrO content is 1% or more. In the glass of the first and third embodiments, the SrO content is preferably 1.2% or more, and more preferably 1.5% or more. In the glass of the second embodiment, the above-mentioned effects are easily obtained if the SrO content is 0.5% or more. The SrO content is preferably 0.6% or more, more preferably 0.7% or more, even more preferably 0.8% or more, even more preferably 1.2% or more, and still more preferably 1.5% or more. In the glass of the fourth embodiment, the above-mentioned effects are easily obtained if the SrO content is 0.1% or more. The SrO content is preferably 0.2% or more, more preferably 0.5% or more, even more preferably 0.6% or more, especially preferably 0.7% or more, even more preferably 0.8% or more, even more preferably 0.9% or more, even more preferably 1% or more, and especially even more preferably 1.5% or more. Furthermore, in the glass of the first embodiment, if the SrO content is 4.5% or less, it is possible to suppress the average thermal expansion coefficient from becoming too high without excessively worsening the acid resistance or increasing the specific gravity. In the glass of the present invention, the SrO content is preferably 4.3% or less, more preferably 4% or less, even more preferably 3.5% or less, even more preferably 3% or less, especially preferably 2.5% or less, and particularly preferably 2% or less. In the glass of the second and third embodiments, if the SrO content is 5% or less, it is possible to suppress the average thermal expansion coefficient from becoming too high without excessively worsening the acid resistance or increasing the specific gravity too much. In the glass of the second and third embodiments, the SrO content is preferably 4.5% or less, more preferably 4% or less, even more preferably 3.5% or less, even more preferably 3% or less, especially preferably 2.5% or less, and particularly preferably 2% or less. In the glass of the fourth embodiment, if the SrO content is 3% or less, it is possible to suppress the average thermal expansion coefficient from becoming too high without excessively worsening the acid resistance or increasing the specific gravity. In the glass of the fourth embodiment, the SrO content is preferably 2.8% or less, more preferably 2.5% or less, even more preferably 2.3% or less, even more preferably 2.2% or less, especially preferably 2.1% or less, and particularly preferably 2% or less.

[0029] In the glass of the present invention, BaO is a component that enhances the moisture resistance of the glass, does not raise the surface devitrification temperature, and improves solubility. Therefore, the glass of the present invention contains 0 to 3% BaO. When BaO is included, the BaO content is preferably 0.1% or more, and more preferably 0.2% or more. If a large amount of BaO is included, the specific gravity increases, the Young's modulus decreases, and the average coefficient of thermal expansion tends to become too large. In addition, the acid resistance of the glass decreases. For this reason, the BaO content is 3% or less, preferably 2% or less, more preferably 1% or less, even more preferably 0.8% or less, even more preferably 0.6% or less, and especially preferably 0.4% or less.

[0030] In the first and second embodiments, the glass has a value of 3.5 to 6 when formula (A) represents the total content of [MgO] + [CaO] + [SrO] + [BaO]. In the third embodiment, the glass has a value of 2 to 6. In the fourth embodiment, the glass has a value of 3.5 to 8. In the glass of the first, second, and fourth embodiments, if the value of formula (A) is 3.5 or higher, the rise in surface devitrification temperature can be suppressed. This improves the quality of the glass and increases productivity when manufacturing glass sheets. In the glass of the first, second, and fourth embodiments, the value of formula (A) is preferably 3.8 or higher, more preferably 4 or higher, even more preferably 4.2 or higher, even more preferably 4.4 or higher, especially preferably 4.6 or higher, even more preferably 4.8 or higher, and even more preferably 5 or higher. In the glass of the third embodiment, if the value of formula (A) is 2 or greater, the rise in surface devitrification temperature can be suppressed. This improves the quality of the glass and increases productivity when manufacturing glass sheets. In the glass of the third embodiment, the value of formula (A) is preferably 3 or higher, more preferably 4 or higher, even more preferably 4.2 or higher, even more preferably 4.4 or higher, especially preferably 4.6 or higher, even more preferably 4.8 or higher, and even more preferably 5 or higher. In the glass of the first to third embodiments, if the value of formula (A) is 6 or less, the dielectric loss tangent in the high-frequency region can be reduced, improving the acid resistance and phase separation characteristics of the glass. In the glass of the first to third embodiments, the value of formula (A) is preferably 5.7 or less, more preferably 5.5 or less, and even more preferably 5.2 or less. In the glass of the fourth embodiment, if the value of formula (A) is 8 or less, the dielectric loss tangent in the high-frequency region can be reduced, improving the acid resistance and phase separation characteristics of the glass. In the glass of the fourth embodiment, the value of formula (A) is preferably 7.5 or less, more preferably 7 or less, even more preferably 6.5 or less, and particularly preferably 6% or less.

[0031] In the first and second embodiments, when formula (B) is expressed as [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]), the value of formula (B) is between -2 and 2. In the third embodiment, the value of formula (B) is between -3 and 2. In the fourth embodiment, the value of formula (B) is between 0 and 3. In the glass of the first embodiment and the glass of the second embodiment, if the value of formula (B) is -2 or greater, the acid resistance and phase separation characteristics of the glass are improved. The values ​​of the glass in the first embodiment and the glass formula (B) in the second embodiment are preferably -1.5 or higher, more preferably -1.2 or higher, even more preferably -1 or higher, even more preferably -0.7 or higher, and especially preferably -0.5 or higher. In the glass of the third embodiment, if the value of formula (B) is -3 or greater, the acid resistance and phase separation characteristics of the glass are improved. In the glass of the third embodiment, the value of formula (B) is preferably -2 or higher, more preferably -1.5 or higher, even more preferably -1.2 or higher, even more preferably -1 or higher, especially preferably -0.7 or higher, and particularly preferably -0.5 or higher. In the glass of the fourth embodiment, if the value of formula (B) is 0 or greater, the acid resistance and phase separation characteristics of the glass are improved. In the glass of the fourth embodiment, the value of formula (B) is preferably 0.1 or higher, more preferably 0.2 or higher, even more preferably 0.4 or higher, even more preferably 0.6 or higher, especially preferably 0.8 or higher, and particularly preferably 1 or higher.

[0032] In the glass of the first to third embodiments, if the value of formula (B) is 2 or less, the rise in surface devitrification temperature can be suppressed. This improves the quality of the glass and increases productivity when manufacturing glass plates. In the glass of the first to third embodiments, the value of formula (B) is preferably 1.5 or less, more preferably 1 or less, even more preferably 0.5 or less, and even more preferably 0.2 or less. On the other hand, if the dielectric loss tangent in the high-frequency range of the glass of the present invention is to be further reduced, specifically if the dielectric loss tangent (tanδ) of the glass of the present invention at a frequency of 35 GHz is to be 0.002 or less, the value of formula (B) is preferably 0 or less, more preferably -0.1 or less, even more preferably -0.2 or less, even more preferably -0.3 or less, especially preferably -0.4 or less, even more preferably -0.5 or less, even more preferably -0.6 or less, even more preferably -0.8 or less, and even more preferably -1 or less. In the glass of the fourth embodiment, if the value of formula (B) is 3 or less, the rise in surface devitrification temperature can be suppressed. This improves the quality of the glass and increases productivity when manufacturing glass plates. In the glass of the fourth embodiment, the values ​​of formula (B) are preferably 2.5 or less, 2.2 or less, 2 or less, more preferably 1.8 or less, even more preferably 1.5 or less, and even more preferably 1.2 or less. On the other hand, if it is desired to further reduce the dielectric loss tangent in the high-frequency range in the glass of the fourth embodiment, specifically, if the dielectric loss tangent (tanδ) of the glass of the present invention at a frequency of 35 GHz is to be 0.002 or less, the value of formula (B) is preferably 1 or less, more preferably 0.9 or less, even more preferably 0.8 or less, even more preferably 0.7 or less, especially preferably 0.6 or less, and even more preferably 0.5 or less.

[0033] In the first to third embodiments of the glass, when formula (C) represents the total content expressed as [SiO2] + [B2O3], the value of formula (C) is preferably 87 to 95. In the fourth embodiment of the glass, the value of formula (C) is 87 to 95. If the value of equation (C) is 87 or higher, the relative permittivity and dielectric loss tangent in the high-frequency range will be low. The glass of the first to third embodiments preferably has a value of formula (C) of 87 or higher, more preferably 87.5 or higher, even more preferably 88 or higher, even more preferably 88.5 or higher, especially preferably 88.7 or higher, and still even more preferably 89 or higher. In the fourth embodiment, the glass has a value of formula (C) of 87.5 or higher, more preferably 88 or higher, even more preferably 88.5 or higher, even more preferably 88.7 or higher, especially preferably 89 or higher, and still more preferably 89.5 or higher. If the value of formula (C) is 95 or less, the glass viscosity is 10 2 The temperature T2 at which the pressure becomes dPa·s (hereinafter referred to as temperature T2) decreases. In the first to third embodiments, the value of formula (C) of the glass is more preferably 93 or less, even more preferably 92 or less, even more preferably 91 or less, and still even more preferably 90 or less. In the fourth embodiment, the glass has a value of formula (C) of 93 or less, more preferably 92 or less, even more preferably 91 or less, and even more preferably 90 or less.

[0034] In the glass of the present invention, when formula (D) is the ratio of content represented by [Al2O3] / [B2O3], the value of formula (D) is preferably 0.1 to 0.3. If the value of formula (D) is within the above range, the acid resistance of the glass is improved. The value of formula (D) is more preferably 0.12 or higher, even more preferably 0.13 or higher, and particularly preferably 0.15 or higher. The value of formula (D) is more preferably 0.28 or less, even more preferably 0.26 or less, even more preferably 0.25 or less, especially preferably 0.23 or less, and still even more preferably 0.2 or less.

[0035] In the first to third embodiments of the glass, when formula (E) is the ratio of content represented by [MgO] / ([MgO]+[CaO]+[SrO]+[BaO]), the value of formula (E) is preferably 0.1 or greater. In the first to third embodiments of the glass, if the value of formula (E) is within the above range, the phase separation characteristics and acid resistance of the glass are improved. The glass of the first to third embodiments is more preferably of formula (E) 0.2 or higher, even more preferably 0.25 or higher, even more preferably 0.3 or higher, especially preferably 0.35 or higher, even more preferably 0.4 or higher, and even more preferably 0.45 or higher. In the glass of the first to third embodiments, there is no particular upper limit to the value of formula (E), but a value of 0.8 or less is preferable because it suppresses deterioration of moisture resistance and suppresses rise in surface devitrification temperature, more preferably 0.7 or less, and even more preferably 0.6 or less. In the fourth embodiment, the value of formula (E) is between 0.5 and 1. If the value of formula (E) is within the above range, the phase separation characteristics and acid resistance of the glass in the fourth embodiment are improved. In the fourth embodiment, the glass has a value of formula (E) of 0.52 or higher, more preferably 0.54 or higher, even more preferably 0.56 or higher, especially preferably 0.58 or higher, and still even more preferably 0.6 or higher. The glass of the fourth embodiment can suppress deterioration of moisture resistance and suppress rise in surface devitrification temperature by having a value of formula (E) of 1 or less. The glass of the fourth embodiment preferably has a value of formula (E) of 0.9 or less, more preferably 0.8 or less, even more preferably 0.75 or less, even more preferably 0.7 or less, even more preferably 0.65 or less, and even more preferably 0.6 or less.

[0036] In the glass of the present invention, when formula (F) is the ratio of content represented by ([MgO]+[CaO]+[SrO]+[BaO]) / [Al2O3], the value of formula (F) is preferably 0.5 to 1.4. If the value of formula (F) is 0.5 or higher, the rise in surface devitrification temperature can be suppressed. This improves the quality of the glass and increases productivity when manufacturing glass sheets. The value of formula (F) is more preferably 0.6 or higher, even more preferably 0.7 or higher, especially preferably 0.8 or higher, even more preferably 0.85 or higher, even more preferably 0.9 or higher, even more preferably 0.95 or higher, even more preferably 0.97 or higher, and even more preferably 1 or higher. If the value of equation (F) is 1.4 or less, the acid resistance and phase separation properties of the glass will improve. The value of formula (F) is more preferably 1.3 or less, even more preferably 1.2 or less, and especially preferably 1.1 or less.

[0037] In the glass of the present invention, when formula (G) is the ratio of content represented by [BaO] / [MgO], the value of formula (G) is preferably 0.01 to 3. If the value of formula (G) is 0.01 or greater, the moisture resistance of the glass and its phase separation characteristics are improved. A value of 0.02 or greater is more preferable, 0.03 or greater is even more preferable, 0.04 or greater is even more preferable, 0.05 or greater is particularly preferable, and 0.06 or greater is even more preferable. If the value of formula (G) is 3 or less, the deterioration of the glass's acid resistance can be suppressed. The value of formula (G) is more preferably 2.5 or less, even more preferably 2 or less, even more preferably 1 or less, especially preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, even more preferably 0.15 or less, and even more preferably 0.1 or less.

[0038] The glass of the present invention, when the amount of H is represented by formula (H) [SiO2]-[B2O3], The value of formula (H) is preferably between 20 and 50. If the value of formula (H) is 20 or higher, the acid resistance of the glass is improved. A value of formula (H) of 23 or higher is more preferable, 25 or higher is even preferable, 27 or higher is even preferable, 28 or higher is particularly preferable, 29 or higher is even preferable, 30 or higher is even preferable, 31 or higher is even preferable, and 32 or higher is even preferable. If the value of equation (H) is 50 or less, the dielectric loss tangent in the high-frequency region can be reduced. By lowering the dependence of the dielectric loss tangent on cooling, the deterioration of the dielectric loss tangent due to rapid cooling can be suppressed, resulting in superior productivity. The value of formula (H) is more preferably 45 or less, even more preferably 40 or less, even more preferably 38 or less, especially preferably 37 or less, even more preferably 36 or less, and even more preferably 35 or less.

[0039] In the glass of the present invention, when formula (I) is the ratio of the content represented by ([SrO]+[BaO]) / ([MgO]+[CaO]), the value of formula (I) is preferably 0.05 to 4. If the value of formula (I) is 0.05 or greater, the dielectric loss tangent in the high-frequency range can be reduced while maintaining the phase separation characteristics of the glass. In addition, the moisture resistance of the glass is improved. The value of formula (I) is more preferably 0.1 or greater, even more preferably 0.2 or greater, even more preferably 0.3 or greater, especially preferably 0.4 or greater, and still most preferably 0.5 or greater. If the value of formula (I) is 4 or less, the deterioration of the glass's acid resistance can be suppressed. The value of formula (I) is more preferably 3 or less, even more preferably 2.5 or less, even more preferably 2 or less, especially preferably 1.8 or less, even more preferably 1.6 or less, even more preferably 1.4 or less, even more preferably 1.2 or less, and even more preferably 1 or less.

[0040] In the first embodiment, when the content ratio of formula (J) is expressed as ([MgO]+[CaO]) / ([MgO]+[CaO]+[SrO]+[BaO]), the value of formula (J) is between 0.2 and 0.7. If the value of formula (J) is 0.2 or higher, the phase separation characteristics of the glass can be improved and the deterioration of acid resistance can be suppressed. The value of formula (J) is preferably 0.25 or higher, more preferably 0.3 or higher, even more preferably 0.35 or higher, even more preferably 0.4 or higher, especially preferably 0.45 or higher, and still even more preferably 0.5 or higher. If the value of formula (J) is 0.7 or less, the moisture resistance of the glass is improved. The value of formula (J) is preferably as follows, more preferably 0.68 or less, even more preferably 0.66 or less, even more preferably 0.64 or less, and especially preferably 0.62 or less.

[0041] In the second embodiment, when the content ratio of formula (K) is represented by [SiO2] / ([SiO2]+[B2O3]), the value of formula (K) is between 0.59 and 0.7. If the value of formula (K) is 0.59 or higher, the moisture resistance and acid resistance of the glass are improved. The value of formula (K) is preferably 0.6 or higher, more preferably 0.62 or higher, even more preferably 0.63 or higher, even more preferably 0.64 or higher, especially preferably 0.65 or higher, and still even more preferably 0.66 or higher. If the value of formula (K) is 0.7 or less, the solubility of the glass improves. The value of formula (K) is preferably 0.69 or less, and more preferably 0.68 or less.

[0042] In the second embodiment, when the amount of glass is expressed by formula (L) as 119-(106×[SiO2]+60×[Al2O3]+119×[B2O3]+37×[MgO]+32×[CaO]+32×[SrO]+33×[BaO]+36×[Li2O]+20×[Na2O]+13×[K2O]), the value of formula (L) is between 16 and 30. Formula (L) is an index representing a measure of the basicity of an oxide, and a value of 16 or higher tends to improve the moisture resistance of the glass. The value represented by formula (L) is preferably 16.1 or higher, more preferably 16.2 or higher, even more preferably 16.3 or higher, even more preferably 16.4 or higher, especially preferably 16.5 or higher, and still even more preferably 16.6 or higher. Furthermore, if the value of formula (L) is 30 or less, the deterioration of the glass's acid resistance can be suppressed. The value of formula (L) is preferably 28 or less, more preferably 26 or less, even more preferably 24 or less, even more preferably 22 or less, especially preferably 20 or less, and still even more preferably 19 or less.

[0043] In the glass of the present invention, when formula (M) is an amount represented by 0.46 × [MgO] + 0.36 × [CaO] + 0.29 × [SrO] + 0.26 × [BaO], the value of formula (M) is preferably between 1.5 and 2.5. Formula (M) is an index of the total cation strength of alkaline earth metals in the glass. When the value of formula (M) is 1.5 or higher, the deterioration of the glass's acid resistance can be suppressed. A value of 1.6 or higher is more preferable, 1.7 or higher is even more preferable, 1.8 or higher is even more preferable, 1.85 or higher is particularly preferable, and 1.9 or higher is still even preferable. Furthermore, when the value of formula (M) is 2.5 or less, the moisture resistance of the glass improves, and the phase separation characteristics tend to improve. A value of formula (M) of 2.4 or less is more preferable, 2.3 or less is even more preferable, 2.2 or less is even more preferable, 2.1 or less is particularly preferable, 2.05 or less is even more preferable, and 2 or less is especially preferable.

[0044] In the glass of the present invention, when formula (N) is (0.46×[MgO]+0.36×[CaO]+0.29×[SrO]+0.26×[BaO]) / ([MgO]+[CaO]+[SrO]+[BaO]), the value of formula (N) is preferably 0.3 to 0.4. Formula (N) is an index of the average cation strength of alkaline earth metals in glass. When the value of formula (N) is 0.3 or higher, the dielectric loss tangent in the high-frequency range tends to decrease. In addition, the moisture resistance of the glass is improved, and the phase separation characteristics tend to improve. A value of formula (N) of 0.32 or higher is more preferable, 0.33 or higher is even more preferable, 0.34 or higher is even more preferable, and 0.35 or higher is particularly preferable. Furthermore, if the value of formula (N) is 0.4 or less, the deterioration of the glass's acid resistance can be suppressed. A value of formula (N) of 0.39 or less is more preferable, 0.38 or less is even more preferable, and 0.37 or less is even more preferable.

[0045] In the glass of the present invention, when formula (O) is the ratio of the content represented by ([CaO]+[SrO]) / ([MgO]+[CaO]+[SrO]+[BaO]), the value of formula (O) is preferably 0.3 to 0.8. When the value of formula (O) is 0.3 or higher, the moisture resistance of the glass and its phase separation characteristics are improved. A value of 0.35 or higher is more preferable, 0.4 or higher is even more preferable, 0.45 or higher is even more preferable, 0.47 or higher is particularly preferable, 0.5 or higher is even more preferable, and 0.52 or higher is especially preferable. Furthermore, if the value of formula (O) is 0.8 or less, the deterioration of the glass's acid resistance can be suppressed. The value of formula (O) is more preferably 0.75 or less, even more preferably 0.7 or less, even more preferably 0.67 or less, especially preferably 0.65 or less, still even more preferably 0.62 or less, and particularly preferably 0.6 or less.

[0046] In the glass of the present invention, when formula (P) is the ratio of the content represented by [CaO] / [SrO], the value of formula (P) is preferably 0.1 to 4. If the value of formula (P) is 0.1 or higher, the deterioration of the glass's acid resistance can be suppressed. A value of formula (P) of 0.2 or higher is more preferable, 0.25 or higher is even more preferable, 0.3 or higher is even more preferable, 0.35 or higher is particularly preferable, 0.4 or higher is even more preferable, and 0.45 or higher is especially preferable. Furthermore, if the value of formula (P) is 4 or less, the moisture resistance of the glass and the phase separation characteristics are improved. The value of formula (P) is more preferably 3 or less, even more preferably 2 or less, even more preferably 1.6 or less, even more preferably 1.2 or less, even more preferably 1 or less, and particularly preferably 0.8 or less.

[0047] The glass of the present invention may contain Fe to improve the solubility of the glass. However, from the viewpoint of reducing the coloration of the glass, the transmittance in the visible range, and the relative permittivity and dielectric loss tangent in the high-frequency range, the Fe content is preferably 0.5 mol% or less, more preferably 0.2 mol% or less, and even more preferably 0.1 mol% or less, in terms of Fe2O3. The Fe content is preferably 0.15% or less, more preferably 0.1% or less, even more preferably 0.05% or less, and even more preferably 0.03% or less, expressed as a mass percentage based on the oxide equivalent of Fe2O3.

[0048] The glass of the present invention has a β-OH value of 0.05 mm -1 ~1.0mm -1 This is preferable. The β-OH value is an indicator of the water content in the glass. After mirror polishing both sides of the glass sample to a thickness of 0.7 to 2.0 mm, FT-IR is used to measure the wavenumber of 4000 to 2000 cm.-1 Transmittance measurements were performed within the specified range. Wavenumber 4000 cm² -1 Transmittance in τ1 (%), wavenumber 3700-3500 cm -1 The minimum transmittance was denoted as τ2 (%), and the thickness of the glass sample was denoted as X (mm). The β-OH value was then calculated using the following formula. Unless otherwise specified, the thickness of the glass sample was adjusted so that τ2 fell within the range of 20-60%. β-OH(mm -1 ) = (1 / X)log 10 (τ1 / τ2) β-OH value is 0.05 mm -1 If the above is true, the glass viscosity is 10 2 The resistance value at temperature T2, where the resistance is dPa·s, is low, making it suitable for melting the glass by electric heating, and also resulting in fewer bubble defects in the glass. Specifically, the β-OH value is 0.05 mm. -1 Solubility improves when the β-OH value is 1.0 mm. -1 The following conditions can suppress bubble defects in the glass. The β-OH value is 0.8 mm. -1 The following is more preferable: 0.7 mm -1 The following is even more preferable: 0.6 mm -1 The following is even more preferable: The β-OH value is 0.1 mm -1 The above is more preferable, 0.2 mm -1 The above is even more preferable, 0.25 mm -1 The above is even more preferable, 0.3 mm -1 The above is particularly preferable, 0.35 mm -1 The above are particularly preferable.

[0049] The glass of the present invention has a Δβ-OH value of 0 mm, calculated by the following method. -1 ~0.1mm -1 That is the case. Δβ-OH is 0 mm -1 ~0.1mm -1 Therefore, glass exhibits excellent moisture resistance. Δβ-OH is 0.08 mm -1 The following is preferred: 0.07 mm -1 The following is more preferable: 0.06 mm -1 The following are even more preferable. Method: The β-OH of a 1.0 mm thick glass plate made of alkali-free glass was measured, and then the glass plate was left to stand at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate was measured 90 hours after the start of standing. The value obtained by subtracting the β-OH before standing from the β-OH after standing was calculated as Δβ-OH.

[0050] The glass of the present invention preferably contains substantially no alkali metal oxides such as Li2O, Na2O, and K2O. In the present invention, "substantially free of alkali metal oxides" means that they are not contained except for unavoidable impurities introduced from the raw materials, etc., that is, they are intentionally excluded.

[0051] For example, the total alkali metal oxide content is preferably 0.3% or less, more preferably 0.2% or less, even more preferably 0.1% or less, even more preferably 0.08% or less, especially preferably 0.05% or less, and particularly preferably 0.03% or less.

[0052] However, specific effects (lowering the strain point, glass transition temperature (T)) g Lower the temperature T2, lower the glass viscosity 4 A predetermined amount of alkali metal oxide may be included for the purpose of lowering the temperature T4 at which dPa·s occurs (hereinafter referred to as temperature T4), lowering the electrical resistance, etc. Specifically, when the total content is represented by formula (Q) as [Li2O] + [Na2O] + [K2O], at least one alkali metal oxide selected from the group consisting of Li2O, Na2O, and K2O may be included such that the value of formula (Q) is 0.5 or less. If the value of formula (Q) is 0.5 or less, the dielectric loss tangent in the high-frequency region will be low, and it will be suitable for use as a substrate for thin-film transistors (TFTs). The value of formula (Q) is more preferably 0.4 or less, even more preferably 0.35 or less, even more preferably 0.3 or less, especially preferably 0.25 or less, even more preferably 0.2 or less, even more preferably 0.15 or less, even more preferably 0.1 or less, and even more preferably 0.05 or less.

[0053] In the glass of the present invention, when formula (R) is the ratio of the content represented by [Li2O] / ([Li2O]+[Na2O]+[K2O]), the value of formula (R) is preferably 0.3 or higher. If the value of formula (R) is within the above range, the relative permittivity and dielectric loss tangent in the high-frequency region are kept low, while the strain point and T are also kept low. g By lowering the annealing point, temperature T2, and temperature T4, or by lowering the resistance value of the glass, the productivity of glass production can be improved. The value of formula (R) is more preferably 0.4 or higher, even more preferably 0.5 or higher, even more preferably 0.6 or higher, and especially preferably 0.7 or higher. The value of formula (R) is preferably 0.95 or lower.

[0054] To improve the clarity of the glass, the glass of the present invention may contain at least one selected from the group consisting of SnO2, Cl, and SO3 in a total content of 0.5% or less. The total content of these is preferably 0.4% or less, more preferably 0.3% or less, even more preferably 0.2% or less, and still more preferably 0.1% or less. The total content of SnO2, Cl, and SO3 is preferably 0.5% or less, more preferably 0.3% or less, and even more preferably 0.1% or less, expressed as a mass percentage based on oxides. The SnO2 content is preferably 0.5% or less, more preferably 0.4% or less, and even more preferably 0.3% or less. The SnO2 content is preferably 0.3% or less, more preferably 0.2% or less, and even more preferably 0.1% or less, expressed as a mass percentage based on oxides.

[0055] To improve the acid resistance of the glass while lowering the dielectric constant and dielectric loss tangent in the high-frequency range, the glass of the present invention may contain at least one selected from the group consisting of Sc2O3, TiO2, ZnO, Ga2O3, GeO2, Y2O3, ZrO2, Nb2O5, In2O3, TeO2, HfO2, Ta2O5, WO3, Bi2O3, La2O3, Gd2O3, Yb2O3, and Lu2O3 as a trace component. To improve the acid resistance of the glass, the total content of the trace component is preferably 0.1% or more and 0.15% or more. On the other hand, to suppress the rise in surface devitrification temperature and the deterioration of the phase separation characteristics of the glass, the total content of the trace component is preferably 1% or less, and more preferably 0.8% or less, 0.6% or less, 0.4% or less, and 0.25% or less. Furthermore, among the above trace components, it is preferable to include ZrO2 from the viewpoint of moisture resistance. To improve acid resistance while suppressing deterioration of moisture resistance, 0.1% or more and 0.3% or more are preferred, and to suppress the rise in surface devitrification temperature and the deterioration of phase separation characteristics, 1% or less and 0.6% or less are preferred. In addition, among the above trace components, it is preferable to include Y2O3 from the viewpoint of surface devitrification temperature and moisture resistance. To improve acid resistance while suppressing the rise in surface devitrification temperature and deterioration of moisture resistance, 0.1% or more and 0.3% or more are preferred, and to suppress the deterioration of phase separation characteristics, 0.8% or less and 0.4% or less are preferred. The glass of the present invention may contain only one of the above-mentioned trace components, or it may contain two or more of them.

[0056] To improve the solubility of the glass, the glass of the present invention may contain P2O5. The P2O5 content is preferably 2% or less, more preferably 1% or less, even more preferably 0.5% or less, even more preferably 0.3% or less, and especially preferably 0.1% or less. On the other hand, since P2O5 may volatilize and re-agglomerate in the glass molding equipment and fall onto the glass plate, potentially causing foreign matter defects, it is even more preferably 0.05% or less, even more preferably 0.01% or less, even more preferably 0.005% or less, and most preferably substantially absent. In the present invention, substantially absent P2O5 means that it is not contained except as an unavoidable impurity introduced from the raw materials, that is, it is intentionally omitted.

[0057] To improve the solubility of glass, to lower the strain point of glass, T g For purposes such as lowering the temperature, lowering the annealing point, and lowering the dielectric loss tangent, the glass of the present invention may contain F. The F content is preferably 0.1 mol% or more, more preferably 0.2 mol% or more, and even more preferably 0.4 mol% or more. However, from the viewpoint of suppressing the deterioration of glass quality due to the volatilization of F, the F content is preferably 1.5 mol% or less, more preferably 1 mol% or less, even more preferably 0.5 mol% or less, and even more preferably 0.1 mol% or less. The F content is preferably 0.01% or more by mass percentage, more preferably 0.03% or more. The upper limit is preferably 0.2% or less, more preferably 0.1% or less, and even more preferably 0.05% or less.

[0058] In order to improve the solubility, clarity, and moldability of the glass, to obtain absorption at specific wavelengths, and to improve density, hardness, bending rigidity, and durability, the glass of the present invention may contain at least one selected from the group consisting of Se2O3, TeO2, Ga2O3, In2O3, GeO2, CdO, BeO, and Bi2O3. From this viewpoint, the total content of these is preferably 2% or less, more preferably 1% or less, even more preferably 0.5% or less, even more preferably 0.3% or less, especially preferably 0.1% or less, even more preferably 0.05% or less, and even more preferably 0.01% or less.

[0059] In order to improve the solubility, clarity, and moldability of the glass, and also to improve the hardness of the glass, such as Young's modulus, the glass of the present invention may contain rare earth oxides and transition metal oxides.

[0060] The glass of the present invention may contain at least one rare earth oxide selected from the group consisting of Sc2O3, Y2O3, La2O3, Ce2O3, Pr2O3, Nd2O3, Pm2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, and Lu2O3. The total content of these is preferably 2% or less, more preferably 1% or less, even more preferably 0.5% or less, even more preferably 0.3% or less, especially preferably 0.1% or less, even more preferably 0.05% or less, and even more preferably 0.01% or less.

[0061] The glass of the present invention may contain at least one transition metal oxide selected from the group consisting of V2O5, Ta2O3, Nb2O5, WO3, MoO3, and HfO2. The total content of these is preferably 2% or less, more preferably 1% or less, even more preferably 0.5% or less, even more preferably 0.3% or less, especially preferably 0.1% or less, even more preferably 0.05% or less, and even more preferably 0.01% or less.

[0062] To improve the solubility of the glass, the glass of the present invention may contain ThO2, an actinide oxide. The ThO2 content is preferably 2% or less, more preferably 1% or less, even more preferably 0.5% or less, even more preferably 0.3% or less, especially preferably 0.1% or less, even more preferably 0.05% or less, even more preferably 0.01% or less, and even more preferably 0.005% or less.

[0063] The glass of the present invention preferably has an ultraviolet transmittance of 2% or more, as measured under the following conditions. An ultraviolet transmittance of 2% or more indicates that the phase separation characteristics of the glass are good. An ultraviolet transmittance of 10% or more is more preferable, 30% or more is even more preferable, and 50% or more is even more preferable. In addition, the ultraviolet transmittance is usually 90% or less. Condition: A 2.0mm thick glass plate with a glass viscosity of 10 4 The glass is heated to a temperature T4 (°C) where the dPa·s pressure is obtained, and then slowly cooled at 40°C / min. After slowly cooling to room temperature (25°C), the parallel light transmittance at a wavelength of 308 nm is measured for a glass that has been mirror-finished on both sides to a thickness of 1.3 mm. In this specification, the parallel light transmittance is the value measured according to the method in accordance with JIS-K-7136 (2000), and is obtained by subtracting the diffuse transmittance from the total light transmittance.

[0064] The dielectric loss tangent (tanδ) of the glass of the present invention at a frequency of 35 GHz is preferably 0.005 or less. If the dielectric loss tangent at 35 GHz is 0.005 or less, dielectric loss in the high-frequency region exceeding 30 GHz can be reduced. The dielectric loss tangent at 35 GHz is more preferably 0.004 or less, even more preferably 0.003 or less, even more preferably 0.0025 or less, especially preferably 0.002 or less, and still more preferably 0.0015 or less. There is no particular lower limit, but for example, 0.0005 or more is preferred. Furthermore, the dielectric loss tangent at 10 GHz is preferably 0.003 or less, more preferably 0.0025 or less, even more preferably 0.002 or less, and even more preferably 0.0015 or less. The lower limit is not particularly limited, but for example, 0.0005 or more is preferred.

[0065] The relative permittivity of the glass of the present invention at a frequency of 35 GHz is preferably 5 or less. If the relative permittivity at 35 GHz is 5 or less, dielectric loss in the high-frequency range can be reduced. The relative permittivity at 35 GHz is more preferably 4.8 or less, even more preferably 4.7 or less, even more preferably 4.6 or less, especially preferably 4.5 or less, even more preferably 4.3 or less, even more preferably 4.2 or less, even more preferably 4.1 or less, and even more preferably 4 or less. The lower limit is not particularly limited, but for example, 3 or more is preferred. Furthermore, the relative permittivity at 10 GHz is preferably 5 or less, more preferably 4.8 or less, even more preferably 4.6 or less, even more preferably 4.4 or less, and especially preferably 4.3 or less. The lower limit is not particularly limited, but for example, 3 or more is preferred.

[0066] The glass of the present invention has a glass transition temperature of T g Set the temperature to °C and the glass to T g The temperature is raised to +100℃, and then T g When the temperature is lowered to -150°C at 10°C / min, the dielectric loss tangent at 10 GHz is tanδ. 10 And similarly, glass T g The temperature is raised to +100℃, and then T g When the temperature is cooled to -150°C at 100°C / min, the dielectric loss tangent at 10 GHz is given by tanδ. 100 When we consider this, -0.0003≦(tanδ 100 -tanδ 10 It is preferable that ) ≤ 0.0003. When this relationship is satisfied, the deterioration of the dielectric loss tangent tanδ can be suppressed even when rapid cooling is performed during glass manufacturing.

[0067] Furthermore, the glass of the present invention has a dielectric loss tangent of tanδ at 10 GHz. A Let the glass transition temperature be T g As such, glass T g The temperature is raised to +100℃, and then T g When the temperature is cooled to -150°C at 100°C / min, the dielectric loss tangent at 10 GHz is given by tanδ. 100When this is done, -0.0003≦(tanδ 100 -tanδ A It is preferable that ) ≤ 0.0003.

[0068] tanδ 100 -tanδ A For the above range to be satisfied, the above tanδ 100 -tanδ 10 The glass composition satisfies the above range, and the glass is T g From +100℃ to T g The cooling rate and time must be adjusted when lowering the temperature to -150°C. During this time, any temperature history is possible, but it is preferable that the equivalent cooling rate A based on the glass's tanδ, as described later, is between 0.01°C / min and 1000°C / min. An equivalent cooling rate A based on tanδ of 0.01°C / min or higher improves the productivity of glass production.

[0069] The equivalent cooling rate A based on tanδ is more preferably 0.1°C / min or more, even more preferably 1°C / min or more, even more preferably 2°C / min or more, especially preferably 5°C / min or more, even more preferably 10°C / min or more, even more preferably 20°C / min or more, even more preferably 30°C / min or more, even more preferably 40°C / min or more, even more preferably 50°C / min or more, especially more preferably 60°C / min or more, even more preferably 70°C / min or more, particularly preferably 80°C / min or more, and most preferably 90°C / min or more.

[0070] Furthermore, if the equivalent cooling rate A based on tanδ is greater than 1000°C / min, tanδ 100 -tanδ A It becomes too small, that is, the dielectric loss tangent tanδ AThis is not preferable because it deteriorates. The equivalent cooling rate A based on tanδ is more preferably 900 °C / min or less, further preferably 800 °C / min or less, still further preferably 700 °C / min or less, even further preferably 600 °C / min or less, yet even further preferably 500 °C / min or less, more preferably 400 °C / min or less, even more preferably 350 °C / min or less, still even more preferably 300 °C / min or less, yet still even more preferably 250 °C / min or less, and particularly preferably 200 °C / min or less.

[0071] Equivalent cooling rate A based on tanδ: The glass plate is heated to T g +100 °C, and then cooled at a constant cooling rate of X °C / min to T g -150 °C to produce a plurality of glasses. The dielectric loss tangent tanδ at 10 GHz is measured. Linear regression is performed so that Log(tanδ) = a × Log(X) + b (a and b are constants). As examples of the cooling rate X °C / min, three levels of 1 °C / min, 40 °C / min, and 200 °C / min may be used. For any glass produced with an arbitrary cooling history, the equivalent cooling rate A is calculated inversely from tanδ using the above regression equation.

[0072] The density of the glass of the present invention is preferably 2.58 g / cm 3 or less. Thereby, the self-weight deflection becomes small, and it becomes easy to handle a large substrate. Also, the weight of a device using the glass can be reduced. The density is more preferably 2.5 g / cm 3 or less, still more preferably 2.4 g / cm 3 or less, even more preferably 2.35 g / cm 3 or less, yet even more preferably 2.3 g / cm 3 or less, and even more preferably 2.3 g / cm or less. The lower limit is not particularly limited, but for example, 2 g / cm 3 or more is preferable. Note that a large substrate is, for example, a substrate having at least one side of 1000 mm or more.

[0073] The alkali-free glass of the present invention preferably has a temperature T2 of 1900°C or lower. When T2 is 1900°C or lower, the glass melting properties are excellent, and the burden on manufacturing equipment can be reduced. For example, the lifespan of equipment such as glass melting furnaces can be extended, and productivity can be improved. Furthermore, defects originating from the furnace, such as pitting and Zr defects, can be reduced. T2 is more preferably 1850°C or lower, even more preferably 1800°C or lower, even more preferably 1750°C or lower, especially preferably 1700°C or lower, and still even more preferably 1680°C or lower. The lower limit of the temperature T2 is not particularly limited, but for example, 1500°C or higher is preferred.

[0074] The glass temperature T4 of the present invention is preferably 1400°C or lower. When the temperature T4 is 1400°C or lower, the glass exhibits excellent formability. Furthermore, for example, by lowering the temperature during glass molding, volatile substances in the atmosphere surrounding the glass can be reduced, thereby reducing defects in the glass. Since glass can be molded at a low temperature, the burden on manufacturing equipment can be reduced. For example, the lifespan of equipment such as the float bath used for glass molding can be extended, and productivity can be improved. The temperature T4 is more preferably 1350°C or lower, even more preferably 1300°C or lower, even more preferably 1270°C or lower, and particularly preferably 1250°C or lower. The lower limit of the temperature T4 is not particularly limited, but for example, 1050°C or higher is preferred.

[0075] Temperatures T2 and T4 were determined by measuring the viscosity using a rotational viscometer according to the method specified in ASTM C 965-96 (2017), and 10 2 dPa·s or 10 4 This is determined as the temperature at which the temperature becomes dPa·s. In the examples described later, NBS710 and NIST717a were used as reference samples for instrument calibration.

[0076] Glass transition temperature T of the glass of the present invention g The temperature is preferably 700°C or lower. g If the temperature is below 700°C, the need to raise the temperature of the annealing device can be avoided, and the reduction in the lifespan of the annealing device can be suppressed. gis more preferably 680 °C or lower, and even more preferably 650 °C or lower. The temperature T g has no particular lower limit, but for example, 450 °C or higher is preferable.

[0077] The annealing point of the glass of the present invention is preferably 700 °C or lower. If the annealing point is 700 °C or lower, it is possible to avoid increasing the temperature of the annealing apparatus and suppress a decrease in the life of the annealing apparatus. The annealing point is more preferably 680 °C or lower, and even more preferably 650 °C or lower. The lower limit of the annealing point is not particularly limited, but for example, 450 °C or higher is preferable.

[0078] The surface devitrification temperature of the glass of the present invention is preferably 1400 °C or lower. If the surface devitrification temperature is 1400 °C or lower, the glass has excellent formability. It is possible to suppress the formation of crystals inside the glass during molding and a decrease in transmittance. In addition, the burden on the manufacturing equipment can be reduced. For example, the life of equipment such as a float bath for molding glass can be extended, and productivity can be improved. The surface devitrification temperature is more preferably 1280 °C or lower, even more preferably 1260 °C or lower, still more preferably 1255 °C or lower, yet more preferably 1250 °C or lower, even yet more preferably 1245 °C or lower, and even more preferably 1240 °C or lower. The lower limit of the surface devitrification temperature is not particularly limited, but for example, 900 °C or higher is preferable. The surface devitrification temperature in the present invention is determined as follows. That is, glass particles pulverized are placed in a platinum dish, heat-treated in an electric furnace controlled at a constant temperature for 17 hours, and after the heat treatment, using an optical microscope, the highest temperature at which crystals precipitate on the surface of the glass and the lowest temperature at which crystals do not precipitate are observed, and the average value thereof is taken as the surface devitrification temperature.

[0079] The average thermal expansion coefficient of the glass of the present invention at 50 to 350 °C is 20×10 -7 / °C or higher is preferable. The average thermal expansion coefficient at 50 to 350 °C is 20×10 -7If the temperature is above 10°C, when using a glass substrate, the difference in thermal expansion between the glass substrate and the metal film formed on the glass substrate can become too large, which can prevent cracking. The average thermal expansion coefficient between 50 and 350°C is 25 × 10⁻⁶. -7 A temperature of 10°C or higher is more preferable. On the other hand, the average coefficient of thermal expansion in the range of 50 to 350°C is 50 × 10⁻⁶. -7 A temperature of 50 × 10⁻⁶ or less is preferred. The average coefficient of thermal expansion at 50 to 350°C is 50 × 10⁻⁶. -7 If the temperature is below / ℃, it is possible to suppress glass breakage during the manufacturing process of products such as high-frequency devices. The average coefficient of thermal expansion between 50 and 350℃ is 40 × 10⁻⁶. -7 / ℃ or lower is more preferable, 37 × 10 -7 More preferably below / ℃, 35 × 10 -7 A temperature of / ℃ or lower is even more preferable.

[0080] The Young's modulus of the glass of the present invention is preferably 40 GPa or higher. If the Young's modulus is within the above range, it is possible to suppress problems such as warping, bending, or cracking of the glass substrate after the deposition of a metal film, such as a Cu film, which is carried out in the manufacturing process of high-frequency devices. A Young's modulus of 43 GPa or higher is more preferable, 45 GPa or higher is even more preferable, and 47 GPa or higher is even more preferable. There is no particular upper limit to the Young's modulus, but for example, 70 GPa or less is preferred.

[0081] The specific modulus of the glass of the present invention is preferably 20 MN·m / kg or higher. If the specific modulus is within the above range, the amount of glass deflection can be suppressed. The specific modulus is more preferably 21 MN·m / kg or higher, and even more preferably 22 MN·m / kg or higher. The upper limit of the specific modulus is not particularly limited, but for example, it is preferably 35 MN·m / kg or less, more preferably 30 MN·m / kg or less, and even more preferably 25 MN·m / kg or less.

[0082] The glass of the present invention exhibits a glass component elution rate of 0.12 mg / cm² per unit surface area when immersed for 170 seconds in an aqueous solution at 45°C containing 6% by mass of HNO3 and 5% by mass of H2SO4. 2The following is preferable. If the amount of glass component elution is within the above range, acid resistance is good. The amount of glass component elution is 0.1 mg / cm³. 2 The following is more preferable: 0.08 mg / cm³ 2 The following is even more preferable: 0.05 mg / cm³ 2 The following are particularly preferable. There is no particular lower limit to the amount of glass components leached out, but for example, 0.0001 mg / cm³ 2 The above is preferable.

[0083] When the glass of the present invention is used as a glass plate with a thickness of 1 mmt, the haze value of the glass plate is preferably 0.5% or less. If the haze value is within the above range, the phase separation characteristics of the glass are excellent, and for example, when the glass substrate is acid-cleaned, localized irregularities on the substrate surface can be effectively prevented. This reduces the transmission loss of high-frequency signals. A haze value of 0.4% or less is more preferable, 0.3% or less is even more preferable, 0.2% or less is even more preferable, and 0.1% or less is particularly preferable. The lower limit of the haze value is not particularly limited, but for example, 0.01% or higher is preferred.

[0084] The glass plate containing the glass of the present invention (hereinafter referred to as "the glass plate of the present invention") is suitable for applications such as glass substrates for high-frequency devices, panel antennas, window glass, vehicle window glass, and touch panel cover glass, due to the above-mentioned features.

[0085] Figure 1 is a cross-sectional view showing an example of the configuration of a circuit board for high-frequency devices. The circuit board 1 shown in Figure 1 comprises an insulating glass substrate 2, a first wiring layer 3 formed on the first main surface 2a of the glass substrate 2, and a second wiring layer 4 formed on the second main surface 2b of the glass substrate 2. The first and second wiring layers 3 and 4 form a microstrip line as an example of a transmission line. The first wiring layer 3 constitutes a signal line, and the second wiring layer 4 constitutes a ground line. However, the structure of the first and second wiring layers 3 and 4 is not limited to this. Furthermore, the wiring layers may be formed on only one of the main surfaces of the glass substrate 2.

[0086] The first and second wiring layers 3 and 4 are layers formed of a conductor, and their thickness is typically around 0.1 to 50 μm. The conductors forming the first and second wiring layers 3 and 4 are not particularly limited, and for example, metals such as copper, gold, silver, aluminum, titanium, chromium, molybdenum, tungsten, platinum, and nickel, or alloys and metal compounds containing at least one of these metals can be used. The structure of the first and second wiring layers 3 and 4 is not limited to a single-layer structure, but may have a multi-layer structure, such as a laminated structure of a titanium layer and a copper layer. The method for forming the first and second wiring layers 3 and 4 is not particularly limited, and for example, various known formation methods such as printing using a conductor paste, dipping, plating, vapor deposition, and sputtering can be applied.

[0087] When the glass plate of the present invention is used as the glass substrate 2, it is preferable that the dielectric loss tangent (tanδ) of the glass substrate 2 at a frequency of 35 GHz is 0.005 or less. If the dielectric loss tangent of the glass substrate 2 at a frequency of 35 GHz is 0.005 or less, dielectric loss in the high-frequency region exceeding 30 GHz can be reduced. The dielectric loss tangent of the glass substrate 2 at a frequency of 35 GHz is more preferably 0.004 or less, even more preferably 0.003 or less, even more preferably 0.0025 or less, especially preferably 0.002 or less, and still more preferably 0.0015 or less. A relative permittivity of 5 or less at a frequency of 35 GHz is preferable because it reduces dielectric loss in the high-frequency range. A relative permittivity of 4.8 or less at a frequency of 35 GHz is more preferable, 4.7 or less is even more preferable, 4.6 or less is even more preferable, 4.5 or less is particularly preferable, 4.3 or less is even more preferable, 4.2 or less is even more preferable, 4.1 or less is even more preferable, and 4 or less is even more preferable.

[0088] Furthermore, the glass substrate 2 has main surfaces 2a and 2b and an end face. At least one of the main surfaces 2a and 2b on which the first and second wiring layers 3 and 4 are formed on the glass substrate 2 preferably has an arithmetic mean roughness Ra of 1.5 nm or less, and more preferably both main surfaces have an arithmetic mean roughness Ra of 1.5 nm or less. If the arithmetic mean roughness Ra of the main surfaces is within the above range, even if the skin effect occurs on the first and second wiring layers 3 and 4 in a high-frequency region exceeding 30 GHz, the skin resistance of the first and second wiring layers 3 and 4 can be reduced, thereby reducing conductor loss. The arithmetic mean roughness Ra of the main surfaces 2a and 2b of the glass substrate 2 is more preferably 1 nm or less, and even more preferably 0.5 nm or less. The main surface of the glass substrate 2 refers to the surface on which the wiring layer is formed. If the wiring layer is formed on one of the main surfaces, it is sufficient that the arithmetic mean roughness Ra of that one main surface satisfies the condition of 1.5 nm or less. In this specification, the arithmetic mean roughness Ra refers to the value in accordance with JIS B0601 (2001).

[0089] The surface roughness of the main surfaces 2a and 2b of the glass substrate 2 can be achieved as needed by polishing the surface of the glass substrate 2. For polishing the surface of the glass substrate 2, for example, polishing using an abrasive mainly composed of cerium oxide or colloidal silica and a polishing pad; polishing using a polishing slurry containing an abrasive and an acidic or alkaline dispersion medium and a polishing pad; or polishing using an acidic or alkaline etching solution. These polishing treatments are applied according to the surface roughness of the raw material of the glass substrate 2, and for example, pre-polishing and finish polishing may be applied in combination. In addition, it is preferable to chamfer the edges of the glass substrate 2 to prevent cracking, chipping, or breakage of the glass substrate 2 caused by the edges during process flow. The chamfering can be any of the following: C-chamfering, R-chamfering, thread chamfering, etc.

[0090] The use of such a glass substrate 2 can reduce the transmission loss of the circuit board 1 at a frequency of 35 GHz. For example, it can be reduced to 1 dB / cm or less. Therefore, the characteristics such as quality and intensity of high-frequency signals, especially high-frequency signals exceeding 30 GHz, and even high-frequency signals above 35 GHz, are maintained, making it possible to provide a glass substrate 2 and circuit board 1 suitable for high-frequency devices that handle such high-frequency signals. In other words, the characteristics and quality of high-frequency devices that handle such high-frequency signals can be improved. The transmission loss of the circuit board 1 at a frequency of 35 GHz is preferably 0.5 dB / cm or less.

[0091] The shape of the glass plate of the present invention is not particularly limited, but a thickness of 0.7 mm or less is preferred. When the glass plate thickness is 0.7 mm or less, it can be used as a glass substrate for high-frequency devices to make high-frequency devices thinner, smaller, and improve production efficiency. In addition, the ultraviolet transmittance is improved, and manufacturability can be enhanced by using ultraviolet curing materials in the device manufacturing process. The thickness of the glass plate is more preferably 0.6 mm or less, even more preferably 0.5 mm or less, even more preferably 0.4 mm or less, especially preferably 0.3 mm or less, still even more preferably 0.2 mm or less, and most preferably 0.1 mm or less. The lower limit is about 0.01 mm.

[0092] When the glass plate is used as a large substrate, it is preferable that at least one side is 1000 mm or longer, more preferably 1500 mm or longer, and even more preferably 1800 mm or longer. There is no particular upper limit, but the size of one side is usually 4000 mm or less. The glass plate is also preferably rectangular.

[0093] Next, the method for manufacturing a glass plate according to the present invention will be described. When manufacturing a glass plate, the process involves a melting step in which glass raw materials are heated to obtain molten glass, a clarification step in which bubbles are removed from the molten glass, a molding step in which the molten glass is formed into a plate shape to obtain a glass ribbon, and a slow cooling step in which the glass ribbon is slowly cooled to room temperature. Alternatively, a method may be used in which the molten glass is formed into a block shape, slowly cooled, and then cut and polished to produce a glass plate.

[0094] The melting process involves preparing the raw materials to achieve the target glass composition, continuously feeding the raw materials into a melting furnace, and heating them to a temperature of preferably 1450 to 1750°C to obtain molten glass. In this embodiment, the alkali-free glass has a low resistance value in the temperature range where the glass raw materials melt, for example, around 1500°C. Therefore, it is preferable to use an electric melting furnace and melt the glass by electric heating. However, electric heating and heating with a burner may be used in combination.

[0095] The raw materials can also include halides such as oxides, carbonates, nitrates, hydroxides, and chlorides. In processes where molten glass comes into contact with platinum during dissolution or clarification, minute platinum particles may dissolve into the molten glass and become foreign matter in the resulting glass plate. However, using nitrate raw materials is effective in preventing the formation of platinum foreign matter.

[0096] As nitrates, strontium nitrate, barium nitrate, magnesium nitrate, calcium nitrate, etc. can be used. The use of strontium nitrate is more preferable. The particle size of the raw materials can be used as appropriate, from large particles of several hundred μm that do not leave any undissolved residue, to small particles of several μm that do not scatter during raw material transport and do not aggregate as secondary particles. Granulated materials can also be used. The water content of the raw materials can be adjusted as appropriate to prevent scattering of the raw materials. β-OH value, redox degree of Fe (redox [Fe 2+ / ( Fe 2+ +Fe 3+ The dissolution conditions for )) can also be adjusted as appropriate.

[0097] The next clarification step is to remove bubbles from the molten glass obtained in the dissolution step described above. For the clarification step, a defoaming method by reduced pressure may be applied, or defoaming may be performed by raising the temperature above the dissolution temperature of the raw materials. SO3 or SnO2 can also be used as a clarifying agent. As an SO3 source, sulfates of at least one element selected from Al, Na, K, Mg, Ca, Sr, and Ba are preferred, and sulfates of alkaline earth metals are more preferred, with CaSO4·2H2O, SrSO4, and BaSO4 being particularly preferred because they have a significant effect in increasing the size of bubbles.

[0098] In the defoaming method by reduced pressure, the use of halogens such as Cl or F is preferred as a clarifying agent. As a Cl source, chlorides of at least one element selected from Al, Mg, Ca, Sr, and Ba are preferred, alkaline earth metal chlorides are more preferred, and among these, SrCl2·6H2O and BaCl2·2H2O are even more preferred because they significantly increase foam volume and have low deliquescence. As a F source, fluorides of at least one element selected from Al, Na, K, Mg, Ca, Sr, and Ba are preferred, alkaline earth metal fluorides are more preferred, and among these, CaF2 is even more preferred because it significantly increases the solubility of the glass raw material.

[0099] Tin compounds, such as SnO2, generate O2 gas in molten glass. In molten glass, at temperatures of 1450°C or higher, SnO2 is reduced to SnO, generating O2 gas and promoting the growth of large bubbles. During the manufacture of glass plates, the glass raw materials are heated to approximately 1450-1750°C to melt, which allows the bubbles in the molten glass to grow more effectively. When using SnO2 as a clarifying agent, it is preferable to prepare the raw materials so that they contain 0.01% or more of the tin compound in terms of SnO2, relative to 100% of the total amount of the base composition. A SnO2 content of 0.01% or more is preferable because it provides a clarifying effect during the melting of the glass raw materials. A SnO2 content of 0.05% or more is more preferable, and 0.1% or more is even more preferable. A SnO2 content of 0.3% or less is preferable because it suppresses the occurrence of glass discoloration and devitrification. The tin compound content in the glass is more preferably 0.25% or less, even more preferably 0.2% or less, and even more preferably 0.15% or less, based on SnO2 equivalent relative to 100% of the total amount of the glass matrix composition.

[0100] The next molding step is to form the molten glass, from which bubbles have been removed in the clarification step described above, into a plate shape to obtain a glass ribbon. As for the molding step, known methods for forming glass into a plate shape can be applied, such as the float method, in which molten glass is poured onto a molten metal such as tin to form a plate shape and obtain a glass ribbon; the overflow downdraw method (fusion method), in which molten glass is poured downwards from a trough-shaped member; and the slit downdraw method, in which molten glass is poured down through a slit. Among these, the float method or the fusion method are preferred from the viewpoint of no polishing or light polishing.

[0101] Next, the annealing process involves cooling the glass ribbon obtained in the molding process down to room temperature under controlled cooling conditions. The annealing process involves cooling the glass ribbon to form a glass ribbon, and then further annealing it down to room temperature under predetermined conditions. After cutting the annealed glass ribbon, a glass plate is obtained.

[0102] If the cooling rate in the slow cooling process is too high, distortion is likely to remain in the glass after cooling. Also, if the equivalent cooling rate, a parameter that reflects the virtual temperature, becomes too high, the shrinkage of the glass cannot be reduced. For this reason, it is preferable to set R so that the equivalent cooling rate is 800°C / min or less. The equivalent cooling rate is more preferably 600°C / min or less, even more preferably 400°C / min or less, even more preferably 300°C / min or less, especially preferably 200°C / min or less, even more preferably 100°C / min or less, even more preferably 60°C / min or less, and particularly preferably 40°C / min or less. On the other hand, if the cooling rate is too low, the process time becomes too long, resulting in low productivity. For this reason, it is preferable to set it to 0.1°C / min or more, more preferably 0.5°C / min or more, and even more preferably 1°C / min or more. The equivalent cooling rate, a parameter that reflects the virtual temperature, is based on the refractive index for ease of evaluation.

[0103] Here, the definition and evaluation method of the equivalent cooling rate based on the refractive index are as follows: A glass sample is prepared by processing a glass of the target composition into a rectangular parallelepiped measuring 10 mm × 10 mm × 0.3 to 2.0 mm. The glass sample is heated in an infrared electric furnace and held at the strain point + 170°C for 5 minutes, after which the glass sample is cooled to room temperature (25°C). At this time, multiple glass samples are prepared by changing the cooling rate in the range of 1°C / min to 1000°C / min.

[0104] Using a precision refractive index measuring device (e.g., Shimadzu Devices KPR3000), the refractive index n of multiple glass samples at the d-line (wavelength 587.6 nm) is measured. d Measure the n. The V-block method or the minimum angle method may be used for measurement. d By plotting n against the logarithm of the cooling rate, we can see the relationship between the above cooling rate and n d Obtain a calibration curve.

[0105] Next, n of glass of the same composition that was actually manufactured through processes such as melting, molding, and cooling. d The obtained n is measured by the measurement method described above. d The corresponding cooling rate (referred to as the equivalent cooling rate in this embodiment) is determined from the calibration curve described above. In glass samples cooled at a constant rate, the equivalent cooling rate based on tanδ and the equivalent cooling rate based on the refractive index are the same. However, in the case of complex cooling processes, a difference may arise between the equivalent cooling rate based on tanδ and the equivalent cooling rate based on the refractive index.

[0106] The method for manufacturing the glass plate of the present invention is not limited to the above. For example, when manufacturing the glass plate of the present invention, the glass may be formed into a plate by a press molding method in which molten glass is directly formed into a plate.

[0107] Furthermore, when manufacturing the glass plate of the present invention, in addition to the manufacturing method using a melting tank made of refractory material, a crucible made of platinum or an alloy mainly composed of platinum (hereinafter referred to as a platinum crucible) may be used in the melting tank or clarification tank. When a platinum crucible is used, the melting process involves preparing the raw materials to achieve the composition of the glass plate to be obtained, heating the platinum crucible containing the raw materials in an electric furnace, preferably to about 1450 to 1700°C, inserting a platinum stirrer, and stirring for 1 to 3 hours to obtain molten glass.

[0108] In the molding process of glass plate manufacturing using a platinum crucible, molten glass is poured onto, for example, a carbon plate or into a mold to form a plate or block. The annealing process is typically T g After maintaining a temperature of approximately +100°C, the glass plate is cooled at a rate of approximately 1-10°C / min to near the strain point, and then cooled to room temperature at a rate that does not leave any residual strain. After cutting to the predetermined shape and polishing, a glass plate is obtained. Alternatively, the cut glass plate can be processed, for example, T g The glass may be heated to approximately +100°C and then slowly cooled to room temperature at a predetermined rate. This allows for adjustment of the equivalent cooling rate of the glass.

[0109] The circuit board 1 using the glass plate of the present invention as the glass substrate 2 is suitable for high-frequency devices that handle high-frequency signals, particularly high-frequency signals exceeding 30 GHz, and even high-frequency signals with frequencies of 35 GHz or higher. It can reduce the transmission loss of such high-frequency signals and improve characteristics such as the quality and strength of the high-frequency signals. The circuit board 1 using the glass plate of the present invention as the glass substrate 2 is suitable for high-frequency devices (electronic devices) such as semiconductor devices used in communication equipment such as mobile phones, smartphones, personal digital assistants, and Wi-Fi devices, as well as surface acoustic wave (SAW) devices, radar components such as radar transceivers, and antenna components such as liquid crystal antennas and panel antennas. In other words, the present invention relates not only to a glass substrate for high-frequency devices containing the glass of the present invention, but also to a panel-type antenna containing the glass of the present invention.

[0110] Furthermore, the glass of the present invention can be suitably applied to other products for the purpose of reducing transmission loss of high-frequency signals. In other words, the present invention also relates to window glass, vehicle window glass, and touch panel cover glass, which include the glass of the present invention. The glass plate containing the glass of the present invention can stably transmit and receive radio waves in the high frequency band and is resistant to damage and breakage, making it suitable for window glass, vehicle windows, and touch panel cover glass. For vehicle windows, for example, windows for autonomous vehicles are more preferable. [Examples]

[0111] Examples will be described below, but the present invention is not limited to these examples. In the following, Examples 1-30, 37-46, and 52-78 are examples, Examples 31-33 are reference examples, and Examples 34-36 and 47-51 are comparative examples.

[0112] Glass plates were prepared with the compositions shown in Examples 1-78 (expressed in mol% based on oxides), a thickness of 1.0 mm, a shape of 50 x 50 mm, and an arithmetic mean roughness Ra of 1.0 nm on the main surface. The glass plates were manufactured by a melting method using a platinum crucible. Raw materials such as silica sand were mixed to obtain glass with the compositions shown in Examples 1-78, and a 1 kg batch was prepared. The raw materials were placed in a platinum crucible and heated in an electric furnace at a temperature of 1650°C for 3 hours to melt and obtain molten glass. During melting, a platinum stirrer was inserted into the platinum crucible and stirred for 1 hour to homogenize the glass. The molten glass was poured onto a carbon plate and formed into a plate shape, and then the plate-shaped glass was T g The sample was placed in an electric furnace at approximately +50°C and held there for 1 hour. The cooling rate was 1°C / min. g The electric furnace was cooled to -150°C, and then the glass was allowed to cool to room temperature. After that, the glass was cut and polished to form a sheet, and a glass plate was obtained. For examples 37-51, the glass plate obtained by cutting was T g Heat to +100℃, hold for 5 minutes, then T g The electric furnace was cooled down to -150°C at a constant cooling rate, and then the glass was allowed to cool to room temperature to obtain a glass substrate with a controlled equivalent cooling rate.

[0113] For glass plates in Examples 1-78, please provide the content of three-coordinate boron, the average thermal expansion coefficient at 50-350°C, the density, and T g Young's modulus, specific modulus, temperature T2, temperature T4, relative permittivity at 10 GHz or 35 GHz, dielectric loss tangent at 10 GHz or 35 GHz, tanδ 100 -tanδ 10 , tanδ 100 -tanδ A Tables 1-15 show the surface devitrification temperature, acid resistance evaluation, the amount of glass components eluted per unit surface area (6%HNO3 + 5%H2SO4 @ 45°C × 170 sec), heat treatment transmittance, β-OH, and Δβ-OH when immersed for 170 seconds in a 45°C aqueous solution containing 6% by mass of HNO3 and 5% by mass of H2SO4, and the transmittance after heat treatment. Values ​​in parentheses in the tables are calculated or estimated values, and blank spaces indicate that the measurement was not performed.

[0114] The measurement methods for each physical property are shown below.

[0115] (B [3] / ( B [3] +B [4] )) The amounts of 3-coordinate boron and 4-coordinate boron in the glass were measured using the Single Pulse method with a JEOL Ltd. ECZ700 under the following conditions. Probe: 3.2mm for solids Rotation speed: 15kHz Flip angle: 30° Pulse repetition waiting time: 16 seconds Standard sample: Adamantane The measurement results were phase-corrected using the NMR software Delta from JEOL Ltd., and the peaks originating from 3-coordinate boron and 4-coordinate boron were separated. The relative abundance of 3-coordinate boron (B) was then calculated from the ratio of the area of ​​each peak. [3] / ( B [3] +B [4] )) was calculated.

[0116] (B [3] (B2O3 conversion)) The percentage (mol %) of tri-coordinate boron contained in the glass, converted to B2O3 equivalent, was calculated using the following formula, which is based on the total amount of B2O3 and the relative abundance of tri-coordinate boron and tetra-coordinate boron. B [3] (B2O3 conversion)=[B2O3]×(B [3] / ( B [3] +B [4] ))

[0117] (Average thermal expansion coefficient) Measurements were taken using a differential thermal expander in accordance with the method specified in JIS R3102 (1995). The measurement temperature range was 50 to 350°C, and the unit was ×10⁻⁶. -7 It was expressed as / ℃.

[0118] (density) The density of a 20g glass mass, free of bubbles, was measured using the Archimedes method.

[0119] (T g ) The measurement was performed using the thermal expansion method in accordance with the method specified in JIS R3103-3 (2001).

[0120] (Young's modulus) Measurements were taken using the ultrasonic pulse method on glass with a thickness of 0.5 to 10 mm, in accordance with the method specified in JIS Z2280 (1993). The unit is expressed as GPa.

[0121] (Specific modulus of elasticity) The specific modulus (MN·m / kg) was calculated by dividing the Young's modulus, measured using the above method, by the density, also measured using the above method.

[0122] (Temperature T2) The viscosity was measured using a rotational viscometer according to the method specified in ASTM C 965-96 (2017), and 10 2 The temperature T2 (°C) at which the pressure was dPa·s was measured.

[0123] (Temperature T4) The viscosity was measured using a rotational viscometer according to the method specified in ASTM C 965-96 (2017), and 10 4 The temperature T4 (°C) at which the pressure was dPa·s was measured.

[0124] (Relative permittivity, dielectric loss tangent) Measurements were performed using a cavity resonator and a vector network analyzer, in accordance with the method specified in JIS R1641 (2007). The measurement frequency was 10 GHz or 35 GHz, which are the resonant frequencies of the air in the cavity resonator.

[0125] (tanδ 100 -tanδ 10 , tanδ 100 -tanδ A ) The dielectric loss tangent of a glass plate at 10 GHz was measured, and tanδ A so 。 Place the glass plate in an infrared heating electric furnace (T g Heat to +100°C, hold for 5 minutes, then cool at a rate of 10°C / min (T g After cooling to -150°C, the dielectric loss tangent at 10 GHz was measured, and tanδ was obtained. 10 That's what I decided. Also, the glass plate is placed in an infrared heating electric furnace (T g Heat to +100°C, hold for 5 minutes, then cool at a rate of 100°C / min (T g After cooling to -150°C, the dielectric loss tangent at 10 GHz was measured, and tanδ was obtained. 100 That's what I decided. From the obtained values, tanδ 100 -tanδ 10 , tanδ 100 -tanδ A The following were calculated for each.

[0126] (Surface devitrification temperature) The glass was crushed and classified using a test sieve to obtain particles in the range of 2-4 mm. The resulting glass cullet was ultrasonically cleaned in isopropyl alcohol for 5 minutes, washed with deionized water, dried, placed in a platinum dish, and heat-treated in an electric furnace controlled to a constant temperature for 17 hours. The heat treatment temperature was set in 10°C increments. After heat treatment, the glass was removed from the platinum dish, and the highest temperature at which crystals precipitated on the glass surface and the lowest temperature at which crystals did not precipitate were observed using an optical microscope. The highest temperature at which crystals precipitate on the glass surface and the lowest temperature at which crystals do not precipitate were each measured once. In cases where it is difficult to determine crystal precipitation, measurements may be taken twice. The average value was calculated using the highest temperature at which crystals precipitated on the glass surface and the lowest temperature at which crystals did not precipitate, and this value was defined as the surface devitrification temperature.

[0127] (Acid resistance, 6%HNO3+5%H2SO4@45℃×170sec) The glass sample was immersed in an acidic aqueous solution (6% by mass HNO3 + 5% by mass H2SO4, 45°C) for 170 seconds, and the amount of glass components eluted per unit surface area (mg / cm³) was measured. 2 The following was evaluated: The amount of glass components eluted was 0.12 mg / cm³. 2 The following conditions indicate good acid resistance.

[0128] (Transmittance after heat treatment) Each glass plate is heated to a temperature T4 (°C), held for 1 minute, and then cooled at a rate of 40°C / min. g The glass was slowly cooled to -150°C. After cooling to room temperature, the parallel light transmittance at a wavelength of 308 nm was measured for the glass that had been mirror-finished on both sides. The parallel light transmittance was measured according to JIS-K-7136 (2000) and was determined by subtracting the diffuse transmittance from the total light transmittance.

[0129] (β-OH) After mirror-polishing both sides of the glass sample to a thickness of 0.7-2.0 mm, FT-IR was used to measure wavenumbers of 4000-2000 cm⁻¹. -1 Transmittance measurements were performed within the specified range. Wavenumber 4000 cm² -1Transmittance in τ1 (%), wavenumber 3700-3500 cm -1 The minimum transmittance was denoted as τ2 (%), and the thickness of the glass sample was denoted as X (mm). The β-OH value was then calculated using the following formula. Unless otherwise specified, the thickness of the glass sample was adjusted so that τ2 fell within the range of 20-60%. β-OH(mm -1 ) = (1 / X)log 10 (τ1 / τ2)

[0130] (Δβ-OH) After measuring the β-OH of a 1.0 mm thick glass plate, the glass plate was left to stand at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate was measured 90 hours after the start of standing. Δβ-OH was calculated by subtracting the β-OH before standing from the β-OH after standing.

[0131] [Table 1]

[0132] In the table, formulas (A) to (R) mean the following, respectively. Formula (A): [MgO]+[CaO]+[SrO]+[BaO] Formula (B): [Al2O3]-([MgO]+[CaO]+[SrO]+[BaO]) Formula (C):[SiO2]+[B2O3] Formula (D): [Al2O3] / [B2O3] Formula (E): [MgO] / ([MgO]+[CaO]+[SrO]+[BaO]) Formula (F):([MgO]+[CaO]+[SrO]+[BaO]) / [Al2O3] Equation (G): [BaO] / [MgO] Formula (H):[SiO2]-[B2O3] Formula (I): ([SrO]+[BaO]) / ([MgO]+[CaO]) Formula (J):([MgO]+[CaO]) / ([MgO]+[CaO]+[SrO]+[BaO]) Equation (K): [SiO2] / ([SiO2]+[B2O3]) Formula (L): 119-(106×[SiO2]+60×[Al2O3]+119×[B2O3]+37×[MgO]+32×[CaO]+32×[SrO]+33×[BaO]+36×[Li2O]+20×[Na2O]+13×[K2O]) Formula (M): 0.46×[MgO]+0.36×[CaO]+0.29×[SrO]+0.26×[BaO] Formula (N): (0.46×[MgO]+0.36×[CaO]+0.29×[SrO]+0.26×[BaO]) / ([MgO]+[CaO]+[SrO]+[BaO]) Formula (O): ([CaO]+[SrO]) / ([MgO]+[CaO]+[SrO]+[BaO]) Formula (P): [CaO] / [SrO] Formula (Q):[Li2O]+[Na2O]+[K2O] Formula (R):[Li2O] / ([Li2O]+[Na2O]+[K2O])

[0133] Table 2

[0134] Table 3

[0135] Table 4

[0136] Table 5

[0137] Table 6

[0138] Table 7

[0139]

Table 8

[0140]

Table 9

[0141]

Table 10

[0142]

Table 11

[0143]

Table 12

[0144]

Table 13

[0145]

Table 14

[0146]

Table 15

[0147] For Examples 1 to 6, Example 8, Examples 10 to 16, Examples 21 to 30, Examples 52 to 54, and Example 64 where the value of formula (A) is 3.5 to 6, the value of formula (B) is -2 to 2, and the value of formula (J) is 0.2 to 0.7, the dielectric tangent at a frequency of 35 GHz is 0.005 or less, the elution amount of the glass component in the acid resistance evaluation is 0.12 mg / cm 2 or less, the transmittance after heat treatment is 2% or more, and Δβ-OH is 0 mm -1 to 0.1 mm-1 That was the case. Examples 5, 7, 9, 13, 14, and 16-18, where the value of equation (A) is 3.5-6, the value of equation (B) is -2-2, the value of equation (K) is 0.55-0.7, and the value of equation (L) is 16-30, have a dielectric loss tangent of 0.005 or less at a frequency of 35 GHz, and the amount of glass component eluted in the acid resistance evaluation is 0.12 mg / cm³. 2 The following conditions apply: the transmittance after heat treatment is 2% or more, and Δβ-OH is 0 mm -1 0.1mm or more -1 The results were as follows: The value of equation (A) is 2 to 6, the value of equation (B) is -3 to 2, B [3] Examples 4, 5, 19, 20, 30, 53, and 54 (B2O3 equivalent) have a dielectric loss tangent of 0.005 or less at a frequency of 35 GHz, and the amount of glass component eluted in the acid resistance evaluation is 0.12 mg / cm³. 2 The following conditions apply: the transmittance after heat treatment is 2% or more, and Δβ-OH is 0 mm -1 ~0.1mm -1 That was the case. Examples 9, 52, and 55-78, where the value of formula (A) is 3.5-8, the value of formula (B) is 0-3, the value of formula (C) is 87-95, and the value of formula (E) is 0.5-1, indicate that the amount of glass component leached during the acid resistance evaluation was 0.12 mg / cm³. 2 The following conditions apply: the transmittance after heat treatment is 2% or more, and Δβ-OH is 0 mm -1 0.1mm or more -1 The results were as follows: Examples 31 and 32, where the value of formula (J) is greater than 0.7 and the value of formula (K) is less than 16, are cases where Δβ-OH is 0.1 mm -1 It was incredible. In Example 33, where the value of formula (J) was greater than 0.7 and the value of formula (K) was less than 16, the transmittance after heat treatment was less than 1%, which was lower than that of the Examples. Example 34, where Al2O3 is less than 2% and the value of formula (B) is less than -3, is an example where Δβ-OH is 0.1 mm -1 It was incredible. Example 35, where the value of equation (A) is greater than 6, is when Δβ-OH is 0.1 mm -1 It was incredible. Al2O3 content is more than 6%, B2O3 content is less than 18%, the value of formula (A) is more than 6%, formula In Example 36 where the value of (B) was less than -3%, the dielectric tangent at 35 GHz was greater than 0.005. -0.0003 ≤ (tanδ 100 -tanδ 10 ) ≤ 0.0003 are satisfied in Examples 1 to 30 and Examples 37 to 46, and even when rapidly cooled in glass production, deterioration of the dielectric tangent can be suppressed. tanδ 100 -tanδ 10 In Examples 36 and Examples 47 to 51 where it is greater than 0.0003, rapid cooling in glass production causes deterioration of the dielectric tangent.

[0148] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. Note that this application is based on a Japanese patent application (Japanese Patent Application No. 2022-027168) filed on February 24, 2022, the entire content of which is incorporated by reference. Also, all references cited herein are incorporated in their entirety.

Industrial Applicability

[0149] The glass of the present invention has a low surface devitrification temperature, excellent acid resistance, moisture resistance, and phase separation characteristics, and can reduce the dielectric loss of high-frequency signals. Such a glass plate containing alkali-free glass is useful for all high-frequency electronic devices handling high-frequency signals of 10 GHz or more, particularly high-frequency signals of 30 GHz or more, and further high-frequency signals of 35 GHz or more, such as glass substrates for communication devices, frequency filter components such as SAW devices and FBARs, bandpass filters such as waveguides and SIW (Substrate integrated waveguide) components, radar components, antenna components (particularly liquid crystal antennas optimal for satellite communication), window glass, vehicle window glass, cover glass for touch panels, display panels, etc.

Explanation of Signs

[0150] 01: Circuit board 2: Glass substrate 2a, 2b: Main surfaces 3,4: Wiring layers

Claims

1. In mole percent based on oxides Yes ２ 50-76, Al ２ O ３ 2~6、 B ２ O ３ 18~35、 MgO 1-3.5 CaO 0.5-4, SrO 1-4.5 It contains BaO 0 to 3, Equation (A) is [MgO] + [CaO] + [SrO] + [BaO], and the value of equation (A) is between 3.5 and 6. Equation (B) is [Al ２ O ３ ] - ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above formula (B) is between -2 and 2. Equation (J) is ([MgO] + [CaO]) / ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above equation (J) is between 0.2 and 0.

7. Δβ-OH calculated by the following method is 0 mm －１ to 0.1 mm －１ and which is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing.

2. In mole percent based on oxides Yes ２ 50-67, Al ２ O ３ 2~6、 B ２ O ３ 18~35、 MgO 1-5.5 CaO 0-4.5 SrO 0.5-5, It contains BaO 0 to 3, Equation (A) is [MgO] + [CaO] + [SrO] + [BaO], and the value of equation (A) is between 3.5 and 6. Equation (B) is [Al ２ O ３ ] - ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above formula (B) is between -2 and 2. Equation (K) is [SiO ２ ] / ([SiO ２ ] + [B ２ O ３ ]) and the value of formula (K) is 0.59 to 0.7, Equation (L) is 119 - (106 × [SiO ２ ] + 60 × [Al ２ O ３ ] + 119 × [B ２ O ３ ]+37×[MgO]+32×[CaO]+32×[SrO]+33×[BaO]+36×[Li ２ O] + 20 × [Na ２ O] + 13 × [K ２ O) and the value of the above formula (L) is 16 to 30, Δβ-OH calculated by the method below is 0 mm －１ ~0.1 mm －１ It is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing.

3. In mole percent based on oxides Yes ２ 50-68, Al ２ O ３ 2~6、 B ２ O ３ 26.5~35、 MgO 1-5, CaO 0-5, SrO 1-5, It contains BaO 0 to 3, Equation (A) is [MgO] + [CaO] + [SrO] + [BaO], and the value of equation (A) is between 2 and 6. Equation (B) is [Al ２ O ３ ] - ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above formula (B) is between -3 and 2. The amount of three-coordinate boron contained in the glass is expressed as B in mole percent based on oxides. ２ O ３ The conversion range is 0 to 26. Δβ-OH calculated by the method below is 0 mm －１ ~0.1 mm －１ It is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing.

4. Alkali-free glass according to any one of claims 1 to 3, wherein the ultraviolet transmittance measured under the following conditions is 2% or more. Condition: A glass plate with a thickness of 2.0 mm is subjected to glass viscosity 10 ４ Temperature T at which dPa·s occurs ４ After heating to (°C) and slowly cooling to room temperature at 40°C / min, the parallel light transmittance at a wavelength of 308 nm is measured on a glass plate that has been mirror-finished on both sides to a thickness of 1.3 mm.

5. The alkali-free glass according to any one of claims 1 to 3, wherein the dielectric loss tangent at a frequency of 35 GHz is 0.005 or less.

6. Density is 2.58 g / cm³ ３ The average coefficient of thermal expansion between 50 and 350°C is 20 × 10⁻⁶. －７ / ℃~50×10 －７ Alkali-free glass according to any one of claims 1 to 3, wherein the temperature is / °C.

7. Glass viscosity 10 ２ Temperature T at which dPa·s occurs ２ At 1500-1900°C, glass viscosity 10 ４ Temperature T at which dPa·s occurs ４ Alkali-free glass according to any one of claims 1 to 3, wherein the temperature is 1400°C or lower.

8. Alkali-free glass according to any one of claims 1 to 3, wherein the glass transition temperature is 700°C or lower.

9. Alkali-free glass according to any one of claims 1 to 3, wherein the surface devitrification temperature is 1400°C or lower.

10. A glass plate containing alkali-free glass according to any one of claims 1 to 3, having a main surface and an end surface, wherein at least one of the main surfaces has an arithmetic mean roughness Ra of 1.5 nm or less.

11. A glass plate containing alkali-free glass as described in any one of claims 1 to 3, having a main surface and an end surface, wherein at least one side is 1000 mm or longer and the thickness is 0.7 mm or less.

12. A method for manufacturing a glass plate, comprising producing alkali-free glass according to any one of claims 1 to 3 by the float method or the fusion method.

13. A method for manufacturing a glass plate containing alkali-free glass according to any one of claims 1 to 3, To obtain molten glass by heating glass raw materials, Removing bubbles from the molten glass, To obtain a glass ribbon by forming the molten glass into a plate, and The glass ribbon is slowly cooled to room temperature. Includes, The aforementioned slow cooling is a method for manufacturing a glass plate, wherein the glass ribbon is slowly cooled such that the equivalent cooling rate is 800°C / min or less.

14. In mole percent based on oxides Yes ２ 58-70, Al ２ O ３ 4.5-8 B ２ O ３ 18~28、 MgO 0.5-5, CaO 0.1-3, SrO 0.1-3, It contains BaO 0 to 3, Equation (A) is [MgO] + [CaO] + [SrO] + [BaO], and the value of equation (A) is between 3.5 and 8. Equation (B) is [Al ２ O ３ ] - ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above formula (B) is between 0 and 3. Equation (C) is [SiO ２ ] + [B ２ O ３ ] and the value of formula (C) is 87 to 95, Equation (E) is [MgO] / ([MgO] + [CaO] + [SrO] + [BaO]), and the value of the above equation (E) is between 0.5 and 1. Δβ-OH calculated by the method below is 0 mm －１ ~0.1 mm －１ It is alkali-free glass. Method: After measuring the β-OH content of a 1.0 mm thick glass plate made of alkali-free glass, The glass plate is left standing at a temperature of 60°C and a relative humidity of 95%. The β-OH of the glass plate is measured 90 hours after the start of standing. Δβ-OH is calculated by subtracting the β-OH before standing from the β-OH after standing.

Images