glass

Abstract

The present invention relates to glass comprising, in mole percent on an oxide basis, 52 to 80% of SiO2, 5 to 30% of B2O3, 2 to 30% of Al2O3, 0.1 to 11% of P2O5, and 0.0001 to 5% of Na2O, and having an average thermal expansion coefficient α at 50 to 350°C of 5×10-7 / °C or more and less than 33×10-7 / °C.

Description

[Technical Field]

[0001] This invention relates to glass suitable for the top plate of a heater. [Background technology]

[0002] In heating appliances such as cookers, the top plate on which the object to be heated, such as a pot, is placed requires heat resistance. For this reason, crystallized glass plates with an extremely low coefficient of thermal expansion are used.

[0003] For example, Patent Document 1 states that the average thermal expansion coefficient in the range of 30 to 750°C is -5 × 10 -7 ~30×10 -7 The glass composition at / °C is disclosed.

[0004] Furthermore, Patent Document 2 states that the average thermal expansion coefficient is 15 × 10 in the range of 50 to 350°C. -7 ~30×10 -7 The glass composition at / °C is disclosed. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-100229 [Patent Document 2] Japanese Patent Publication No. 2018-203571 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, crystallized glass plates generally consist of two phases: a crystalline phase and a glass phase. Therefore, although they have heat resistance, they have manufacturing difficulties due to the need for uniform heat treatment, and there was a problem in that the plate thickness could not be increased.

[0007] Examples of common glass plates include TEMPAX (registered trademark of SCHOTT) containing B2O3 to provide heat resistance. However, since the average thermal expansion coefficient is about 33×10 -7 / °C, it was the upper limit for the average thermal expansion coefficient that could be manufactured in a normal melting furnace.

[0008] Therefore, in order to lower the average thermal expansion coefficient, it is conceivable to further increase the content of B2O3 or add Al2O3. However, when the content of B2O3 is increased, the viscosity of the molten glass becomes high, and it becomes impossible to manufacture in a normal melting furnace. Also, when adding Al2O3, devitrification or phase separation is likely to occur during manufacturing depending on the addition amount.

[0009] To solve these problems, it is effective to add Na2O to the glass components, but there was a problem that when Na2O is contained, the average thermal expansion coefficient becomes high, that is, it becomes highly expanded. Although a thick heat-resistant member with a large plate thickness has been desired, heretofore, no glass plate that realizes low expansion, devitrification suppression, and phase separation suppression in good balance has been found.

[0010] Furthermore, when used as a top plate on which an object to be heated such as a pot is placed, there was a problem of breakage during heating due to damage caused by contact with the pot.

[0011] An object of the present invention is to provide a low-expansion glass excellent in low expansion and heat resistance, and excellent in devitrification suppression and phase separation suppression, and a heat-resistant member using such glass.

Means for Solving the Problems

[0012] <1> In terms of molar percentage representation based on oxides, SiO2; 52 - 80%, B2O3; 5 - 30%,​​​​​​​It contains an average thermal expansion coefficient α of 5 × 10 at 50 to 350°C. -7 / ℃ or higher 33×10 -7 Glass with a temperature below / ℃. <2> Linear transmittance T at a wavelength of 850 nm for a glass plate thickness of 15 mm 850 The above is 87.5% or more <1> The glass described above. <3> Furthermore, expressed as a mole percentage based on oxides, Fe2O3; 0.00001~0.03% The above <1> or <2> The glass described above. <4> The aforementioned glass is expressed in mole percentage based on oxides, SiO2 + Al2O3; 76.5~85% R2O: 0.01~5%, (However, R2O is at least one of either Li2O or K2O.) The above <1> ~ <3> Glass as described in one of the following. <5> Furthermore, expressed as a mole percentage based on oxides, MgO; 0.1-10% The above <1> ~ <4> Glass as described in one of the following. <6> Furthermore, expressed as a mole percentage based on oxides, CaO; 0.1-3% The above <1> ~ <5> Glass as described in one of the following. <7> The aforementioned glass is expressed as a mole percentage based on oxides, SiO2; 55-68%, Al2O3; 8.5-30% Furthermore, the ratio of P2O5 to Al2O3 is P2O5 / Al2O3; 0.1~1.0 The above <1> ~ <6> Glass as described in one of the following. <8> The aforementioned glass is expressed as a mole percentage based on oxides, SiO2 + Al2O3 + B2O3 + P2O5; 89 - 99%, and the ratio of the sum of Al2O3 and B2O3 to SiO2 + P2O5 is (Al2O3 + B2O3) / (SiO2 + P2O5) ≥ 0.3 The glass according to any one of <1> to <7> above. <9> The glass is expressed in terms of molar percentage based on oxides, (CaO + Na2O + P2O5) / Al2O3 ≥ 0.35 The glass according to any one of <6> to <8> above. <10> A glass plate made of the glass according to any one of <1> to <9> above. <11> The glass plate according to <10> above, having a plate thickness of 4 - 150 mm. <12> A heat-resistant member obtained by bonding a ceramic having a thermal conductivity of 25 Wm / K or more to the glass plate according to <><10> or <11>. <13> The difference in expansion coefficient in the range of 50 - 200 °C of the ceramic having a thermal conductivity of 25 Wm / K or more bonded to the glass plate according to <><10> or <11> is within the range of ±6.0×10 -7 / °C. The heat-resistant member obtained by bonding the ceramic. <14> The heat-resistant member according to <12> or <13> above, wherein the ceramic is bonded by fluororesin bonding.

Effect of the Invention

[0013] According to an embodiment of the present invention, it is possible to provide a low-expansion glass excellent in low expansion and heat resistance, and excellent in devitrification suppression and phase separation suppression, and a heat-resistant member using the glass.

Mode for Carrying Out the Invention

[0014] Hereinafter, the glass of an embodiment of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be modified and implemented as desired without departing from the spirit of the invention.

[0015] [Explanation of terms] In this specification, the following shall apply: The "~" symbol indicates that the value is greater than or equal to its lower limit and less than or equal to its upper limit. The composition of the glass is expressed as a mole percentage based on oxides, and the content of components whose valency is prone to change in the glass is expressed by converting it to a representative oxide. Unless otherwise specified, "%" refers to the mole percentage based on the oxide. "Substantially free" in relation to the glass composition means that, with the exception of unavoidable impurities, it does not contain any of the specified substances. The glass in one embodiment of the present invention refers to amorphous glass in which no diffraction peaks indicating crystallinity are observed by X-ray diffraction, and does not include crystallized glass.

[0016] [glass] A glass according to one embodiment of the present invention contains, in molar percentages based on oxides, SiO2; 52-80%, B2O3; 5-30%, Al2O3; 2-30%, P2O5; 0.1-11%, and Na2O; 0.0001-5%, and has an average thermal expansion coefficient α of 5 × 10 at 50-350°C. -7 / ℃ or higher 33×10 -7 It is below / ℃.

[0017] SiO2 is an essential and main component for forming the glass network. SiO2 is present in a concentration of 52% or more to enhance the heat resistance of the glass and make it more resistant to mechanical impacts. A SiO2 content of 55% or more is preferable, 60% or more is more preferable, and 65% or more is even preferable.

[0018] SiO2 is included at a concentration of 80% or less to reduce viscosity during glass manufacturing. The SiO2 content is preferably 78% or less, more preferably 75% or less, even more preferably 70% or less, and particularly preferably 68% or less.

[0019] The range of SiO2 content can be specified by any combination of these upper and lower limits.

[0020] B2O3 is an essential component for promoting the melting of glass raw materials while maintaining low expansion. B2O3 is included in a concentration of 5% or more to improve mechanical properties and weather resistance and to achieve low expansion. The B2O3 content is preferably 8% or more, more preferably 10% or more, even more preferably 12% or more, and particularly preferably 13% or more.

[0021] B2O3 is contained at a concentration of 30% or less to prevent problems such as the formation of reams due to volatilization, erosion of the furnace wall, and reduced water resistance. The B2O3 content is preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less.

[0022] The range of B2O3 content can be specified by any combination of these upper and lower limits.

[0023] Al2O3 is an essential component for forming and modifying the glass network. Al2O3 is present in amounts of 2% or more to enhance the heat resistance of the glass, as well as for weather resistance and suppression of phase separation. The Al2O3 content is preferably 5% or more, more preferably 8.5% or more, even more preferably 10% or more, and even more preferably 13% or more.

[0024] Al2O3 is included at a concentration of 30% or less to reduce viscosity and suppress devitrification during glass manufacturing. The Al2O3 content is preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less. The range of the Al2O3 content can be specified by any combination of these upper and lower limits.

[0025] P2O5 is an essential component for preventing crystallization and devitrification of glass. P2O5 is present in a concentration of 0.1% or more to stabilize the glass. A P2O5 content of 2% or more is more preferable, 3% or more is even more preferable, and 3.5% or more is particularly preferable.

[0026] P2O5 is included in an amount of 11% or less because it can stabilize the glass without making its high-temperature viscosity too high. The P2O5 content is preferably 9.5% or less, more preferably 9% or less, even more preferably 8% or less, and particularly preferably 5% or less.

[0027] The range of P2O5 content can be specified by any combination of these upper and lower limits.

[0028] Na2O is an essential component for improving the electrical conductivity of glass at high temperatures, promoting the melting of glass raw materials, and adjusting the thermal expansion coefficient and viscosity of glass. Na2O is present in amounts of 0.0001% or more to improve the solubility, clarity, and moldability of glass at high temperatures. The Na2O content is preferably 0.0005% or more, more preferably 0.01% or more, and even more preferably 0.5% or more.

[0029] Na2O is included in glass at a concentration of 5% or less to reduce the coefficient of thermal expansion, thereby reducing the stress generated during temperature changes and suppressing cracking due to thermal shock. From the viewpoint of achieving a desired average coefficient of thermal expansion, the Na2O content is preferably 3% or less, more preferably 2.5% or less, and even more preferably 1% or less.

[0030] The range of Na2O content can be specified by any combination of these upper and lower limits.

[0031] The average thermal expansion coefficient α of the glass in one embodiment of the present invention is 5 × 10 in the temperature range of 50 to 350°C. -7 / ℃ or higher 33×10 -7 It is less than / ℃. The average thermal expansion coefficient α is 7 × 10 from the perspective of bonding with ceramics. -7 Preferably above / ℃, 10 × 10 -7 More preferably above / ℃, 15×10 -7 More preferably above / ℃, 20 × 10 -7 A temperature of / ℃ or higher is particularly preferred.

[0032] The average coefficient of thermal expansion α is 30 × 10 to reduce thermal stress generated during temperature changes and suppress cracking due to thermal shock. -7 Preferably below / ℃, 28 × 10 -7 / ℃ or lower is more preferable, 27 × 10 -7 A temperature of / ℃ or lower is even more preferable.

[0033] In one embodiment of the present invention, the glass has a linear transmittance T at a wavelength of 850 nm when the glass plate thickness is 15 mm. 850 By setting the transmittance to 87.5% or higher, infrared rays can be efficiently transmitted. Therefore, in the case of a laminate in which SiC is laminated on glass according to one embodiment of the present invention, the SiC can be efficiently heated by infrared rays from a heater irradiated onto the glass side. From the viewpoint of efficiency during heater heating, the linear transmittance T 850 More preferably 88% or more, even more preferably 89% or more, and even more preferably 90% or more.

[0034] Linear transmittance T 850 For example, this can be measured using a double-beam spectrophotometer (V-650 model, manufactured by JASCO Corporation), with measurements taken in the wavelength range of 400 to 1200 nm, and the transmittance at the measurement wavelength of 850 nm is defined as the linear transmittance.

[0035] The glass of one embodiment of the present invention preferably further contains Fe2O3 at a molar percentage of 0.00001 to 0.03% based on oxide. In order to improve the clarity of the glass without impairing the color of the glass and while maintaining the linear transmittance at a wavelength of 850 nm, and to control the temperature of the substrate at the bottom of the melting furnace, the Fe2O3 content is more preferably 0.0001% or more, and even more preferably 0.0005% or more.

[0036] To maintain the color of the glass, the Fe2O3 content is more preferably 0.02% or less, and even more preferably 0.01% or less. The range of Fe2O3 content can be specified by any combination of these upper and lower limits.

[0037] The glass of one embodiment of the present invention preferably contains SiO2 + Al2O3: 76.5-85%, and R2O: 0.01-5% (where R2O is at least one of Li2O or K2O).

[0038] By using a SiO2 + Al2O3 ratio of 76.5-85%, the glass can be made to expand slowly. A combined ratio of SiO2 and Al2O3 of 77% or more is more preferable, and 78% or more is even more preferable.

[0039] To lower the devitrification temperature and enable manufacturing, the combined amount of SiO2 and Al2O3 is more preferably 83% or less, even more preferably 82% or less, and even more preferably 80% or less.

[0040] R2O is a useful component for improving the electrical conductivity of glass at high temperatures. It is also useful for promoting the melting of glass raw materials and for adjusting the thermal expansion coefficient, viscosity, etc., of glass. Here, R2O represents at least one of Li2O or K2O.

[0041] The R2O content is preferably 0.01% or more, more preferably 0.1% or more, and even more preferably 0.5% or more. This reduces the thermal expansion coefficient of the glass, thereby reducing the stress generated during temperature changes.

[0042] The R2O content is preferably 5.0% or less, more preferably 4.0% or less, even more preferably 3.0% or less, and even more preferably 1% or less.

[0043] The range of R2O content can be specified by any combination of these upper and lower limits.

[0044] The glass according to one embodiment of the present invention preferably further contains 0.1 to 10% MgO, expressed as a molar percentage based on oxide. MgO has low expansion while lowering the viscosity of the glass and improving manufacturability, so its content is preferably 0.1% or more, more preferably 0.5% or more, even more preferably 1% or more, and even more preferably 2% or more.

[0045] MgO has low expansion, and to lower the devitrification temperature of the glass and increase productivity, its concentration is preferably 10% or less, more preferably 8% or less, and even more preferably 6% or less.

[0046] The range of MgO content can be specified by any combination of these upper and lower limits.

[0047] The glass according to one embodiment of the present invention preferably further contains CaO in a molar percentage based on oxide, of 0.1 to 3%. CaO is preferably 0.1% or more, more preferably 0.3% or more, and even more preferably 0.5% or more, in order to reduce the viscosity of the glass and improve manufacturability while exhibiting low expansion.

[0048] Furthermore, in order to increase productivity by lowering the devitrification temperature of the glass while maintaining low expansion of CaO, the amount of CaO is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less.

[0049] The range of CaO content can be specified by any combination of these upper and lower limits.

[0050] The glass of one embodiment of the present invention further preferably contains SiO2; 55-68% and Al2O3; 8.5-30% in molar percentages based on oxide, and the ratio of P2O5 to Al2O3 content, P2O5 / Al2O3, is 0.1-1.0.

[0051] If the P2O5 / Al2O3 ratio is less than 0.1, the glass becomes unstable and difficult to vitrify, or the crystallization temperature becomes low. If it is greater than 1.0, there is a risk of reduced chemical resistance, or the viscosity of the glass becomes too high. The P2O5 / Al2O3 ratio is more preferably 0.3 to 0.8, even more preferably 0.35 to 0.7, and most preferably 0.40 to 0.65.

[0052] In one embodiment of the present invention, the glass further contains SiO2 + Al2O3 + B2O3 + P2O5 in molar percentages based on oxides, with a preferred ratio of (Al2O3 + B2O3) / (SiO2 + P2O5) to 0.3 or higher. That is, it is preferable that (Al2O3 + B2O3) / (SiO2 + P2O5) ≥ 0.3. If (Al2O3 and B2O3) / (SiO2 + P2O5) is less than 0.3, the glass becomes unstable and prone to phase separation, or the devitrification temperature becomes low, or the viscosity of the glass becomes too high.

[0053] The ratio of (Al2O3 and B2O3) / (SiO2+P2O5) is preferably 0.33 or higher, and more preferably 0.35 or higher.

[0054] In one embodiment of the present invention, the glass preferably has a molar ratio of (CaO+Na2O+P2O5) / Al2O3 ≥ 0.35, expressed on an oxide basis. If (CaO+Na2O+P2O5) / Al2O3 is less than 0.35, the glass devitrification temperature will be high, which may lead to a deterioration in manufacturing properties.

[0055] The (CaO+Na2O+P2O5) / Al2O3 ratio is preferably 0.4 or higher, and more preferably 0.45 or higher.

[0056] If necessary, the glass of one embodiment of the present invention may contain RO (where RO is at least one of SrO, BaO, and ZnO) to lower the viscosity of the glass, increase its solubility, and control its coefficient of thermal expansion. The RO content is preferably 0.1% or more, more preferably 1.5% or more, and even more preferably 3.0% or more.

[0057] To lower the devitrification temperature of the glass, increase its solubility, and control its coefficient of thermal expansion, the RO (reverse osmosis) content is preferably 12% or less, more preferably 10% or less, even more preferably 7.5% or less, and even more preferably 5% or less.

[0058] The composition of the glass in one embodiment of the present invention is not limited to this in order to achieve the objective, and for example, TiO2, ZrO2, and Y2O3 may be added as appropriate in amounts ranging from 0 to 5% each.

[0059] The method for manufacturing the glass of one embodiment of the present invention is not particularly limited, nor is the method for shaping the molten glass particularly limited, but it can be manufactured, for example, as follows.

[0060] First, glass raw materials are prepared as appropriate, heated to approximately 1600-1700°C to melt, then homogenized by degassing, stirring, etc., and then formed into sheets or blocks by casting using well-known methods such as the float method, down-draw method (fusion method, etc.), press method, roll-out method, or slip-cast method. After slow cooling, they are cut to the desired size to produce glass (glass sheets).

[0061] Polishing is performed as needed, but it is also possible to treat the glass plate surface with a fluorine agent in addition to or instead of polishing. Considering the stable production of glass plates, the float method or the down-draw method is preferred, and the float method is particularly preferred when considering the production of large glass plates.

[0062] Furthermore, when using this glass, it may be physically strengthened to improve its scratch resistance and heat resistance.

[0063] [glass plate] A glass plate according to one embodiment of the present invention is made of the glass described above. That is, it is a glass plate formed from the glass using a desired manufacturing method.

[0064] The thickness of the glass plate is not particularly limited, but from the viewpoint of supporting heavy objects as a top plate on which heating appliances are placed, and from the viewpoint of infrared transmittance as a heat-resistant material as described later, 4 to 150 mm is preferred, 5 to 120 mm is more preferred, 7 to 100 mm is even more preferred, and 10 to 30 mm is even more preferred.

[0065] The shape of the glass plate can be as desired; for example, it may be rectangular or approximately circular.

[0066] [Heat-resistant material] The glass and glass plate of one embodiment of the present invention are not particularly limited in their applications, but because they are low-expansion glass with excellent heat resistance, devitrification suppression, and phase separation suppression, they can be suitably used in various applications such as top plates for heating appliances such as cookers, window materials for high-temperature furnaces, and building materials requiring fire resistance.

[0067] Among these, the top plate of a heating appliance such as a cooking appliance is particularly suitable for use. The cooking appliance may be an induction heating appliance (induction heating appliance), a gas combustion heating appliance (gas heating appliance), or a kitchen glass stand including the cooking appliance.

[0068] Furthermore, since the glass in one embodiment of the present invention is transparent glass and not crystallized glass, coloring components may be added as appropriate depending on the surrounding color tone and design.

[0069] For example, when considering application to the top plate of a cooking appliance, the main surface may be further provided with an organic printing layer using ink containing an inorganic filler, etc., in order to conceal the inside of the cooking appliance. Such an organic printing layer containing an inorganic filler is typically provided on the main surface (back surface) of the cooking appliance's top plate that is opposite to the main surface that comes into contact with the object to be heated. The color tone of the organic printing layer containing an inorganic filler is not particularly limited, but it is preferable to match the color tone with the kitchen counter arranged around the cooking appliance to give a sense of color unity.

[0070] The thermal conductivity of the ceramics attached to the upper surface of the glass plate in one embodiment of the present invention is preferably 25 Wm / K or higher. If it is less than 25 Wm / K, it becomes difficult to raise the temperature rapidly. Preferably it is 35 Wm / K or higher, more preferably 50 Wm / K or higher, even more preferably 100 Wm / K or higher, and even more preferably 150 Wm / K or higher.

[0071] Furthermore, this ceramic material has a coefficient of thermal expansion difference of ±6.0 × 10⁻⁶ compared to glass in the 50-200°C range. -7 Within the range of / ℃ (-6.0 × 10 -7 / ℃ or higher 6.0×10 -7 It is preferable that the temperature is below / ℃. ±6.0 × 10 -7 If the temperature deviates from the specified range of / °C, stress will be generated due to the difference in thermal expansion coefficients between ceramics and glass, which may cause warping or breakage during rapid heating or cooling.

[0072] The above difference in the coefficient of expansion is preferably ±5 × 10 -7 Within the range of / ℃ (-5 × 10 -7 / ℃ or higher 5×10 -7 (below / ℃) more preferably ±3 × 10 -7 Within the range of / ℃ (-3 × 10 -7 / ℃ or higher 3×10 -7 (below / ℃), and more preferably ±1.5 × 10 -7 Within the range of / ℃ (-1.5 × 10 -7 / ℃ or higher 1.5×10 -7 (below / ℃), particularly preferably ±1 × 10-7 Within the range of / ℃ (-1 × 10 -7 / ℃ or higher 1×10 -7 It is below / ℃.

[0073] The average thermal expansion coefficient α of glass at 50-350°C is 5 × 10⁻⁶ -7 / ℃ or higher 33×10 -7 Considering that the temperature is below / ℃, the ceramic material is preferably at least one of SiC, Si-SiC, and Si3N4.

[0074] In Si-SiC, the Si content is preferably 5 to 55 wt%. Below 5 wt%, expansion becomes high, making it difficult to obtain sufficient thermal shock properties. On the other hand, above 55 wt%, the Young's modulus becomes low, and the bending strength decreases. The Si content is preferably 14 to 40 wt%, more preferably 17 to 35 wt%, and particularly preferably 20 to 30 wt%.

[0075] Furthermore, for bonding this ceramic material to glass, a fluororesin is preferable from the viewpoint of heat resistance and acid resistance. Examples of fluororesins include PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer).

[0076] It is preferable to bond a ceramic having a thermal conductivity of 25 Wm / K or more to a glass plate according to one embodiment of the present invention by the fluororesin bonding method.

[0077] Furthermore, the adhesive strength is preferably 25 MPa or higher in tensile strength.

[0078] Furthermore, in order to ensure heat resistance, the glass transition temperature is preferably 150°C or higher, more preferably 200°C or higher, and even more preferably 250°C or higher.

[0079] Furthermore, the Young's modulus is preferably 2.5 GPa or less.

[0080] As described above, bonding the glass plate and ceramics using fluororesin is preferable because it prevents damage to the top plate due to scratches. [Examples]

[0081] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these. Examples 1-27 are examples, and Examples 28-30 are comparative examples.

[0082] [Preparation] The raw materials were prepared to have the compositions shown in Tables 1 and 2, expressed as molar percentages based on oxides. These were placed in a platinum crucible and melted in a resistance-heated electric furnace at 1650°C for 3 hours, then degassed and homogenized. Blank spaces in Tables 1 and 2 indicate the absence of that component. The obtained molten glass was poured into a mold and held at a temperature of glass transition temperature Tg + 50°C for 3 hours, then cooled to room temperature at a rate of 1°C / min to obtain glass blocks for Examples 1-30. Furthermore, glass plates were cut from the obtained glass blocks to obtain glass plates.

[0083] [Average thermal expansion coefficient α] From the obtained glass plate, a round bar measuring φ4.0 mm × length 20 mm was cut out, and the average thermal expansion coefficient α (unit: °C) at 50 to 350 °C was determined according to JIS R 3102. -1 The ) was measured using a thermomechanical analyzer (BRUKER TDS5000SA). The results are shown in Tables 3 and 4.

[0084] [Evaluation of vitreousness] For the obtained glass block, the temperature at which glass devitrification occurs, i.e., the viscosity of the glass, is 10 3 The temperature T3 at which dPa·s was obtained was measured using a rotational viscometer. The solution was held at T3 temperature for 15 hours, and the presence or absence of devitrification was observed visually. Samples with crystals were marked with ×, and those without were marked with ○. The results are shown in Tables 3 and 4.

[0085] [Evaluation of phases] A round rod measuring φ4.0 mm × length 20 mm was cut from the obtained glass block and measured using a thermomechanical analyzer (BRUKER TDS5000SA). Samples that showed bending near Tg and were unmeasurable, and that appeared cloudy to the naked eye, were marked with × (phase separation), while all others were marked with ○ (circle separation). The results are shown in Tables 3 and 4. When phase separation occurs, an accurate thermal expansion coefficient curve cannot be obtained.

[0086] [Linear transmittance] The obtained glass block was cut and polished to obtain a glass plate with a thickness of 15 mm and mirror-finished on both sides. Linear transmittance was measured using a double-beam spectrophotometer (V-650, manufactured by JASCO Corporation). Measurements were taken in the wavelength range of 400 to 1200 nm, and the transmittance at the measurement wavelength of 850 nm was defined as the linear transmittance. The results are shown in Tables 3 and 4.

[0087] [Thermal shock test] The obtained glass plates (Examples 1-30) were polished so that both sides were mirror-finished. The size of the glass plates was then processed to 100mm x 100mm x 4mm, or the size of the composite components (Examples 1, 10, TEMPAX) prepared below was processed to 100mm x 100mm x 22mm. These were heated at 250°C for 10 minutes and then dropped into water three times. If all were destroyed, it was marked as ×, and if none were destroyed, it was marked as ○. Tables 3 and 4 show the evaluation results for the glass plates, and Table 5 shows the evaluation results for the composite components. The evaluation results for Tables 3 and 4 were based on glass plates of size 100mm x 100mm x 4mm, and the evaluation results for Table 5 were based on glass plates of size 100mm x 100mm x 22mm.

[0088] The above composite material was manufactured as follows. First, the glass blocks obtained above (Examples 1 and 10) and TEMPAX (a registered trademark of Corning) were cut and polished to obtain glass plates with a thickness of 15 mm and mirror-like surfaces on both sides.

[0089] Next, the Si-SiC member and SiC member obtained as described below were processed to a thickness of 7 mm and have mirror-like surfaces on both sides to obtain ceramic plates.

[0090] <Si-SiC component> 71.0 wt% of SiC powder (manufactured by Pacific Random Co., Ltd., model number: GMF-12S (average particle size 0.7 μm)), 2.0 wt% of carbon black (average particle size 0.03 μm), 5.5 wt% of Metrose (manufactured by Shin-Etsu Chemical Co., Ltd., model number SM8000) as a binder, and 21.5 wt% of pure water were put into a kneader (manufactured by Miyazaki Iron Works Co., Ltd., model number: MP100) and kneaded for 6 hours to obtain a clay. The obtained clay was put into an extrusion molding machine (manufactured by Miyazaki Iron Works Co., Ltd., model number: FM100) and extruded and molded under the conditions of a head pressure of 1.0 MPa and a discharge rate of 1200 g / min to obtain a molded body. The obtained molded body was dried at 50 °C for 4 days and then heated and degreased at 450 °C in an air atmosphere for 3 hours to obtain a degreased body. The obtained degreased body was fired in a carbon firing furnace at 1700 °C for 2 hours under a vacuum atmosphere of 10 -3 Pa to obtain a sintered body. After firing, Si was infiltrated under the conditions of 1670 °C in an argon atmosphere to obtain a Si-SiC component.

[0091] <SiC component> 93.6 wt% of SiC powder (manufactured by Pacific Random Co., Ltd., model number: GMF-12S (average particle size 0.7 μm)), 1.9 wt% of B4C powder (manufactured by High-Purity Chemical Research Institute Co., Ltd., model number: BBI10PB (average particle size 0.5 μm)) as a sintering aid, 1.5 wt% of carbon powder (manufactured by Showa Denko K.K., model number: UF-G5 (average particle size 3 μm)), 3.0 wt% of polyoxyethylene lauryl ether as a dispersant, anhydrous ethanol as a medium, and high-purity silicon carbide balls with a diameter of 5 mm as grinding media were added to a nylon ball mill pot and mixed and ground for 96 hours with a rotary ball mill. The obtained slurry was dried under reduced pressure to obtain a raw material powder. The obtained raw material powder was weighed so as to obtain a sintered body with the desired thickness, and pressed at a pressure of 2000 kg / cm 2 using a cold isostatic press to obtain a molded body. The obtained molded body was put into a carbon container and sintered in a carbon firing furnace at 2150 °C for 1 hour under a vacuum atmosphere of 10 -3 Pa to obtain a SiC sintered body.

[0092] Next, a 50 μm PFA film was placed on the 7 mm thick ceramic member (Si-SiC member or SiC member) obtained above. Then, the 15 mm thick glass plate obtained above was stacked on top of the film together with the bonding resin described in Table 5. The materials were then heated and pressed at 300°C (above the film's Tg) for 30 minutes at 1 MPa, and cooled to room temperature while under pressure to obtain a composite member of ceramics and glass plate (Examples 1, 10, TEMPAX).

[0093] [Table 1]

[0094] [Table 2]

[0095] [Table 3]

[0096] [Table 4]

[0097] [Table 5]

[0098] Examples 1-27 were low-expansion glasses that exhibited low expansion, excellent heat resistance, superior devitrification and phase splitting suppression, and excellent transmittance at 850 nm and thermal shock resistance. Furthermore, the thermal shock resistance when bonded with ceramics was also superior in the composite members of the examples (Examples 1 and 10) compared to the comparative example using TEMPAX.

[0099] On the other hand, comparative examples 28-30 failed to achieve low expansion, heat resistance, devitrification suppression, and phase splitting suppression simultaneously, and also exhibited inferior thermal shock. Furthermore, because example 29 exhibited phase splitting, an accurate thermal expansion coefficient curve could not be obtained.

[0100] Although various embodiments have been described above, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components in the above embodiments may be combined in any way without departing from the spirit of the invention.

[0101] This application is based on Japanese Patent Application No. 2020-101051 filed on June 10, 2020, and Japanese Patent Application No. 2020-161312 filed on September 25, 2020, the contents of which are incorporated by reference in this application.

Claims

1. Expressed as a mole percentage based on oxides, Yes ２ ; ６１．５～６５．６％、 B ２ O ３ ; ９．４～１４．４％、 Al ２ O ３ ;12~17%、 P ２ O ５ ;3.5~7.9%、 Na ２ O;1.2~3.2%、 comprising and having an average coefficient of thermal expansion α at 50 to 350 °C of 5 × 10 －７ / °C or more and less than 33 × 10 －７ / °C, and Expressed as a mole percentage based on oxides, (CaO + Na ２ O+P ２ O ５ ) / Al ２ O ３ Glass with a viscosity of 0.45 to 0.

71.

2. Linear transmittance T at a wavelength of 850 nm for a glass plate with a thickness of 15 mm. ８５０ The glass according to claim 1, wherein the content is 87.5% or more.

3. Furthermore, expressed as a mole percentage based on oxides, Fe ２ O ３ ;0.00001~0.03% The glass according to claim 1 or 2, comprising the glass.

4. The aforementioned glass is expressed as a mole percentage based on oxides, SiO ２ +Al ２ Oh ３ ;76.5~82%, R ２ O:0.01~5%、 (However, R ２ O is Li ２ O, or K ２ (At least one of O) A glass containing any one of claims 1 to 3.

5. Furthermore, expressed as a mole percentage based on oxides, MgO; 0.1-10% A glass containing any one of claims 1 to 4.

6. Furthermore, expressed as a mole percentage based on oxides, CaO; 0.1-3% A glass containing any one of claims 1 to 5.

7. The aforementioned glass is P, expressed as a mole percentage based on oxides. ２ O ５ and Al ２ O ３ The ratio P ２ O ５ / Al ２ O ３ ;0.3~1.0、 The glass according to any one of claims 1 to 6.

8. The aforementioned glass is expressed as a mole percentage based on oxides, SiO ２ +Al ２ O ３ +B ２ O ３ +P ２ O ５ ;89~99%、 And, Al ２ O ３ and B ２ O ３ The sum of and SiO ２ +P ２ O ５ The ratio (Al ２ O ３ +B ２ O ３ ) / (SiO ２ +P ２ O ５ )≧0.3 The glass according to any one of claims 1 to 7.

9. Linear transmittance T at a wavelength of 850 nm for a glass plate with a thickness of 15 mm. ８５０ The glass according to any one of claims 1 to 8, wherein the percentage is 88% or more.

10. Linear transmittance T at a wavelength of 850 nm for a glass plate with a thickness of 15 mm. ８５０ The glass according to any one of claims 1 to 9, wherein the content is 90% or more.

11. The average thermal expansion coefficient α at 50-350°C is 24.0 × 10⁻⁶. －７ / ℃ or higher 33 x 10 －７ The glass according to any one of claims 1 to 10, wherein the temperature is less than / ℃.

12. A glass plate made of glass according to any one of claims 1 to 11.

13. The glass plate according to claim 12, wherein the thickness of the glass plate is 4 to 150 mm.

14. A heat-resistant member comprising a glass plate according to claim 12 or 13, to which ceramics having a thermal conductivity of 25 Wm / K or more are bonded.

15. The glass plate according to claim 12 or 13 has a thermal conductivity of 25 Wm / K or more, and the difference in the coefficient of thermal expansion in the 50-200°C region is ±6.0 × 10 －７ A heat-resistant component made by bonding ceramics within a temperature range of / °C.

16. The heat-resistant member according to claim 14 or 15, wherein the ceramics are bonded together by fluororesin bonding.

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