Crystallized glass

Abstract

Provided is a white LAS-based crystallized glass which is characterized by containing, in mass%, 55-75% of SiO2, 10-35% of Al2O3, 0.1-3.59% of Li2O, 0-10% of BaO, 0-10% of MgO, 0.2-5% of TiO2, 0-5% of ZrO2, and 0-5% of P2O5, and which is also characterized in that: the following parameters a to d satisfy that a is 0-20%, b is 80% or less, c is 40% or less, and d is 65% or less; and a β-spodumene solid solution is precipitated as a main crystal. a: (Li2O + MgO + CaO + ZnO + TiO2) - (Na2O + K2O), b: Al2O3 + BaO + 4(SrO + ZnO) + 8(CaO + Li2O), c: Al2O3 - (Li2O + MgO) + 2(CaO + SrO + P2O5) - 2(TiO2 + ZrO2) + 3(Na2O + K2O) - 6SnO2, d: Al2O3 + ZnO + P2O5 + 2(MgO + CaO + BaO + ZrO2) + 4TiO2 + 10Na2O

Description

Glass-ceramics

[0001] The present invention relates to glass-ceramics.

[0002] LAS (Li ２ O-Al ２ O ３ -SiO ２ )-based crystallized glasses are used as materials for fire door window panes, stove front windows, image sensor substrates, firing setters, etc.

[0003] For example, Patent Documents 1 to 4 disclose LAS-based crystallized glasses obtained by precipitating LAS-based crystals such as β-quartz solid solution and β-spodumene solid solution as the main crystals.

[0004] LAS-based crystallized glass has a low thermal expansion coefficient and excellent thermal properties because the precipitated crystals have a negative thermal expansion coefficient, and also has high mechanical strength because a large amount of crystals are precipitated.In addition, by appropriately adjusting the heat treatment conditions in the crystallization process, it is possible to control the type of precipitated crystals, and it is possible to produce transparent crystallized glass with a low thermal expansion coefficient and high mechanical strength.

[0005] In the manufacturing process of LAS-based crystallized glass, white crystallized glass in which β-spodumene solid solution is precipitated can be obtained by carrying out crystallization under appropriate heat treatment conditions.

[0006] This type of crystallized glass is used in applications requiring a low thermal expansion coefficient, such as firing setters, and also in microwave oven trays and other applications because it contains β-spodumene solid solution as the main crystal, resulting in low dielectric loss at 2.45 GHz.

[0007] That is, glass-ceramics containing β-spodumene solid solution as the main crystals are characterized by a low thermal expansion coefficient and low dielectric loss, and are white in color.

[0008] In recent years, the cost of glass raw material batches has been rising. In particular, the cost of Li raw materials (Li ２ O) With the spread of small electronic devices such as laptop computers and mobile phones, and electric vehicles, the demand for Li-ion secondary batteries is increasing compared to the supply of Li raw materials, causing prices to rise sharply.

[0009] Due to the above circumstances, there is an increasing demand for reducing the cost of raw material batches in LAS-based crystallized glass. However, it is not easy to realize a transparent LAS-based crystallized glass with a low thermal expansion coefficient while reducing the cost of raw material batches. For example, Li ２ When the O content is reduced, the amount of precipitation of crystals with a low thermal expansion coefficient, such as β-spodumene solid solution, decreases, and the thermal expansion coefficient of the LAS-based crystallized glass tends to increase. Also, since the amount of β-spodumene solid solution decreases, the dielectric loss at 2.45 GHz tends to increase.

[0010] As an example of crystallized glass containing a β-spodumene solid solution, Patent Document 1 discloses Li ２ The present invention discloses a crystallized glass containing 3.6% to 4.2% O by mass, and the thermal expansion coefficient of the glass is 12 to 17×10 －７ / °C, dielectric loss is 35 to 57 × 10 －３ is in the range.

[0011] In addition, Patent Document 2 describes, in mass %, Li ２ Contains about 4% O and has a thermal expansion coefficient of 0.6 to 11 × 10 －７ Further, Patent Document 3 discloses a glass-ceramic having a temperature of 1000°C. ２ Contains 3.6 to 4.2% O and has a thermal expansion coefficient of 6 to 10 × 10 －７ / °C. and also indicates that the appearance and optical properties of ceramics can be changed depending on the heat treatment conditions.

[0012] JP 2016-193832 A JP 2016-108218 A JP 2023-033177 A

[0013] However, in any of the patent documents, Li ２ There is no disclosure of a glass that exhibits excellent properties (white color, low thermal expansion, low dielectric loss) at 3.5 mass % or less of O. ２ It is difficult to reduce the cost of raw material batches when the price of O raw materials rises.

[0014] In view of the above circumstances, an object of the present invention is to provide a ceramic material having a small thermal expansion coefficient and a small dielectric loss, and ２The present invention provides a white LAS-based crystallized glass having a reduced O content and reduced raw material batch costs.

[0015] As a result of intensive research, the present inventors have found that by appropriately designing the composition of LAS-type crystallized glass, it is possible to obtain white LAS-type crystallized glass that has a low thermal expansion coefficient, excellent dielectric loss characteristics, and reduced raw material batch costs.

[0016] The LAS-based crystallized glass according to the first aspect of the present invention contains, in mass %, SiO ２ 55-75%, Al ２ O ３ 10-35%, Li ２ O 0.1-3.59%, BaO 0-10%, MgO 0-10%, TiO ２ 0.2-5%, ZrO ２ 0-5%, P ２ O ５ The present invention is characterized in that it contains 0 to 5% of Li, and satisfies the following parameters a to d: a 0 to 20%, b 80% or less, c 40% or less, and d 65% or less, and β-spodumene solid solution is precipitated as the main crystal. ２ O+MgO+CaO+ZnO+TiO ２ )-(Na ２ O+K ２ O) b: Al ２ O ３ +BaO+4(SrO+ZnO)+8(CaO+Li ２ O) c: Al ２ O ３ -(Li ２ O+MgO)+2(CaO+SrO+P ２ O ５ )-2(TiO ２ + ZrO ２ ) + 3 (Na ２ O+K ２ O)-6SnO ２ d: Al ２ O ３ +ZnO+P ２ O ５ +2(MgO+CaO+BaO+ZrO ２ ) + 4TiO ２ +10Na ２ O

[0017] In the LAS-type crystallized glass according to Aspect 2 of the present invention, in Aspect 1, the above parameters a to d preferably satisfy, in mass%, a: 3 to 10%, b: 30 to 70%, c: 25% or less, and d: 45% or less.

[0018] In the LAS-type crystallized glass according to Aspect 3 of the present invention, in Aspect 1 or 2, Al ２ O ３ 15-30%, Li ２ O 2-3.49%, MgO 0-0.8%, CaO 0-1.6%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３ 30-2000ppm, V ２ O ５ It is preferable that the content is 0 to 1000 ppm.

[0019] In the LAS-type crystallized glass according to Aspect 4 of the present invention, in any one of Aspects 1 to 3, Al ２ O ３ 15-30%, Li ２ O 2.0-3.49%, BaO 2.7-10%, MgO+CaO 0-1.9%, ZrO ２ 1.4-5% Fe ２ O ３ It is preferable that the content is 30 to 10,000 ppm.

[0020] In the LAS-type crystallized glass according to Aspect 5 of the present invention, in any one of Aspects 1 to 4, Al ２ O ３ 15-30%, Li ２ O 2.0-3.5%, Na ２ O+K ２ O > 0~0.9%, BaO 2.6~10%, MgO+CaO 0~4%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３It is preferable that the content is 30 to 10,000 ppm.

[0021] In the LAS-type crystallized glass according to Aspect 6 of the present invention, in any one of Aspects 1 to 5, SiO ２ 55-68%, Al ２ O ３ 20-30%, Li ２ O 2.0-3.49%, Na ２ O+K ２ O 0-0.5%, BaO 0-2.7%, MgO+CaO 0-2.5%, TiO ２ 0.2-3.9%, ZrO ２ 1.4-2.9%, P ２ O ５ 0-2.5% Fe ２ O ３ It is preferable that the content is 30 to less than 900 ppm, and the parameter a satisfies 3 to 8.5%.

[0022] In the LAS-type crystallized glass according to Aspect 7 of the present invention, in any one of Aspects 1 to 6, Pr ６ O １１ It is preferable that the content of the above is 0.1 to 2000 ppm.

[0023] In the LAS-type crystallized glass according to Aspect 8 of the present invention, in any one of Aspects 1 to 7, the LAS-type crystallized glass further contains, in mass %, Sm ２ O ３ It is preferable that the content of the above is 0.1 to 2000 ppm.

[0024] In the LAS-based crystallized glass according to Aspect 9 of the present invention, in any one of Aspects 1 to 8, Li ２ It is preferable that the alloy contains 0.1 to 3.47% of O and 2 to 10% of BaO.

[0025] In the LAS-type crystallized glass according to Aspect 10 of the present invention, in any one of Aspects 1 to 9, Na ２ O+K ２ O The content is preferably more than 0% and less than 0.7%.

[0026] In the LAS-type crystallized glass according to Aspect 11 of the present invention, in any one of Aspects 1 to 10, P is ２ O５ It is preferable that the content is 0.01 to 4%.

[0027] In the LAS-type crystallized glass according to Aspect 12 of the present invention, in any one of Aspects 1 to 11, Fe, ２ O ３ It is preferable that the content is 0 to less than 900 ppm.

[0028] In the LAS-type crystallized glass according to Aspect 13 of the present invention, in any one of Aspects 1 to 12, it is preferable that the glass contains, by mass %, 0 to 0.2% CaO.

[0029] In the LAS-type crystallized glass according to Aspect 14 of the present invention, in any one of Aspects 1 to 13, it is preferable that the following mass % be satisfied: a 5.2 to 8%, b 45 to 55%, c 5 to 15%, and d 30 to 45%.

[0030] In the LAS-based crystallized glass according to Aspect 15 of the present invention, in any one of Aspects 1 to 14, ２ O ３ and Sb ２ O ３ It is preferable that it does not contain

[0031] In the LAS-based crystallized glass according to Aspect 16 of the present invention, in any one of Aspects 1 to 15, Li ２ It is preferable that O / BaO is 2.5 or less.

[0032] In the LAS-based crystallized glass according to Aspect 17 of the present invention, in any one of Aspects 1 to 16, the mass ratio of (Na ２ O+K ２ It is preferable that the ratio of (MgO+MgO) / BaO is 6 or less.

[0033] In the LAS-type crystallized glass according to Aspect 18 of the present invention, in any one of Aspects 1 to 17, the ZnO content is preferably 0 to less than 1.1% by mass.

[0034] Aspect 19 of the present invention provides the LAS-type crystallized glass of any one of Aspects 1 to 18, wherein the thermal expansion coefficient at 30 to 750° C. is −30×10 －７ / ℃~30×10 －７ / °C.

[0035] The LAS-type crystallized glass according to Aspect 20 of the present invention is, in any one of Aspects 1 to 19, L ＊ A value of 50 or less is preferred.

[0036] The LAS-type crystallized glass according to Aspect 21 of the present invention is, in any one of Aspects 1 to 20, L in diffuse reflectance at a thickness of 4 mm ＊ A value of 60 or greater is preferred.

[0037] The LAS-type crystallized glass according to Aspect 22 of the present invention is any one of Aspects 1 to 21, wherein the dielectric loss at a frequency of 2.45 GHz is 48×10 －３ It is preferable that:

[0038] A manufacturing method of LAS-type crystallized glass according to Aspect 23 of the present invention is a manufacturing method for manufacturing the LAS-type crystallized glass according to any one of Aspects 1 to 22, and relates to a manufacturing method of glass, comprising: a step of melting glass raw materials to obtain molten glass; a step of shaping the molten glass; and a step of subjecting the glass obtained in the step of shaping the molten glass to heat treatment to crystallize it.

[0039] According to the present invention, it is possible to obtain an LAS-based crystallized glass having a low thermal expansion coefficient, excellent transparency, and reduced raw material batch costs.

[0040] L in the total light transmittance of the LAS-based crystallized glass of each example of the present invention ＊ 1 is a scatter diagram in which the values ​​of parameter a are plotted against the values ​​of parameter a. FIG. 2 is a scatter diagram in which the total light transmittance at a wavelength of 1500 nm of the LAS-type crystallized glass of each Example of the present invention is plotted against the values ​​of parameter b. FIG. 3 is a scatter diagram in which the thermal expansion coefficient at 30 to 750°C of the LAS-type crystallized glass of each Example of the present invention is plotted against the values ​​of parameter c. FIG. 4 is a scatter diagram in which the dielectric loss values ​​at a frequency of 2.45 GHz of the LAS-type crystallized glass of each Example of the present invention are plotted against the values ​​of parameter d.

[0041] First, the glass composition of the LAS-based glass-ceramics of the present invention will be described. Regarding the content of each component below, "%" means "% by mass" unless otherwise specified.

[0042] SiO ２ is a component that forms the glass skeleton and is also a component of LAS-based crystals. ２ If the content of SiO is too small, the thermal expansion coefficient tends to be high, making it difficult to obtain crystallized glass with excellent thermal shock resistance. Also, the chemical durability tends to be reduced. ２ The content of SiO is preferably 55% or more, 57.5% or more, 60% or more, and more preferably 61% or more. ２ If the content of SiO is too high, the meltability of the glass decreases, the viscosity of the glass melt increases, making it difficult to refine, and the molding of the glass becomes difficult, which tends to reduce productivity. ２ The content is preferably 75% or less, 72.5% or less, 70% or less, 68% or less, or 67.5% or less, and more preferably 65% ​​or less.

[0043] Al ２ O ３ is a component that forms the glass skeleton and is also a component of LAS-based crystals. ２ O ３ is also a component that coordinates around the crystal nucleus and forms a core-shell structure. The presence of a core-shell structure makes it difficult for crystal nucleus components to be supplied from outside the shell, making it difficult for the crystal nucleus to enlarge and facilitating the formation of many tiny crystal nuclei. As a result, it becomes possible to precipitate tiny crystals uniformly in the glass. It is also a component that reduces the high-temperature viscosity of the crystallized glass. Al ２ O ３ If the content of Al is too low, the thermal expansion coefficient tends to be high, making it difficult to obtain crystallized glass with excellent thermal shock resistance. Also, the chemical durability tends to be reduced. ２ O ３ The content of Al is preferably 10% or more, 12.5% ​​or more, 15% or more, 17.5% or more, and more preferably 20% or more.２ O ３ If the content of Al is too high, crystals such as mullite tend to precipitate, causing the glass to devitrify, and the crystallized glass becomes more susceptible to breakage. ２ O ３ The content is preferably 35% or less, 32.5% or less, 30% or less, 27% or less, 26% or less, 25% or less, and more preferably 24% or less.

[0044] Li ２ O is a component of LAS-based crystals and also a component that reduces the viscosity of glass and improves the melting and formability of glass. It is also a component that tends to reduce the refractive index of crystallized glass. ２ If the content of O is too small, crystals such as mullite will precipitate, and the glass will tend to devitrify.In addition, the melting property of glass will be reduced, the viscosity of the glass melt will be increased, making it difficult to clarify, and the molding of glass will be difficult, and productivity will be easily reduced.In addition, since the LAS-based crystals will be difficult to precipitate, the thermal expansion coefficient of the crystallized glass will tend to be increased, and it will be difficult to obtain the crystallized glass with excellent thermal shock resistance.Therefore, Li ２ The content of O is preferably 0.1% or more, 1% or more, 1.5% or more, 2% or more, 2.2% or more, 2.5% or more, or 2.75% or more, and more preferably 3% or more. ２ If the O content is too high, the crystallinity becomes too strong, and the glass tends to be easily devitrified, and the crystallized glass becomes easily broken. ２ Since O is an expensive raw material, the cost of the raw material batch is high. ２ The O content is preferably 3.59% or less, 3.5% or less, 3.49% or less, 3.48% or less, 3.47% or less, 3.46% or less, and more preferably 3.45% or less.

[0045] Na ２ O is a component that affects the crystallinity and also reduces the viscosity of the glass, improving the melting and formability of the glass. It is also a component that adjusts the thermal expansion coefficient and refractive index of the crystallized glass. ２If the O content is too high, the crystallinity becomes too strong, the glass becomes more susceptible to devitrification, and the crystallized glass becomes more susceptible to breakage. ２ The O content is preferably 1% or less, 0.9% or less, 0.7% or less, 0.5% or less, 0.3% or less, or 0.2% or less, and more preferably 0.15% or less. ２ O is easily mixed in as an impurity, so Na ２ If O is completely removed, the cost of the raw material batch tends to increase. ２ The lower limit of the O content is preferably 0% or more, 0.0003% or more, 0.0005% or more, and particularly preferably 0.001% or more.

[0046] K ２ O is a component that affects the crystallinity and also reduces the viscosity of the glass, improving the meltability and formability of the glass. It is also a component that adjusts the thermal expansion coefficient and refractive index of the crystallized glass. ２ If the O content is too high, the crystallinity becomes too strong, the glass becomes more susceptible to devitrification, and the crystallized glass becomes more susceptible to breakage. ２ The O content is preferably 1% or less, 0.9% or less, 0.7% or less, 0.5% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.07% or less, and more preferably 0.04% or less. ２ O is easily mixed in as an impurity, so K ２ If O is completely removed, the cost of the raw material batch tends to increase. ２ The lower limit of the O content is preferably 0% or more, 0.0003% or more, 0.0005% or more, and particularly preferably 0.001% or more.

[0047] As mentioned above, Na ２ O and K ２ O has a similar effect in the present invention. ２ O and K ２ If the combined amount with O is too large, the crystallinity becomes too strong, the glass becomes prone to devitrification, and the crystallized glass becomes prone to breakage. ２O+K ２ O is preferably 2% or less, 1.5% or less, 1% or less, 0.9% or less, 0.7% or less, less than 0.7%, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.17% or less, and more preferably 0.14% or less. ２ O and K ２ Since O is easily mixed in as an impurity, if it is attempted to completely remove it, the cost of the raw material batch tends to increase. ２ O+K ２ The lower limit of O is preferably more than 0%, 0.0006% or more, 0.001% or more, and particularly preferably 0.002% or more.

[0048] BaO is a component that reduces the viscosity of glass and improves the meltability and formability of glass. It is also a component that adjusts the thermal expansion coefficient and refractive index of the crystallized glass. More specifically, the addition of BaO is performed by adding the same amount (same mole) of Na ２ O and K ２The addition of BaO tends to reduce the thermal expansion coefficient of the resulting crystallized glass compared to the addition of O or MgO. Furthermore, the liquidus temperature tends to be lower and the liquidus viscosity tends to be higher, making it easier to ensure productivity. Furthermore, it tends to suppress mullite precipitation during the molding of the crystallized glass. Because mullite-based crystals grow rapidly and are difficult to remove after formation, it is preferable to avoid compositions that are prone to precipitation. In addition, the resulting crystallized glass tends to be less colored and to have less scattering within the glass, making it easier to achieve the desired transparency. Therefore, the BaO content is preferably 0% or more, 0.1% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more, 2.6% or more, 2.7% or more, 3% or more, 3.5% or more, 3.75% or more, 4% or more, 4.1% or more, 4.2% or more, 4.3% or more, or 4.4% or more, and more preferably 4.5% or more. On the other hand, if the BaO content is too high, Ba-containing crystals will precipitate, making the glass more likely to devitrify, and therefore the crystallized glass will be more likely to break.Therefore, the BaO content is preferably 10% or less, 9.5% or less, 9% or less, 8.5% or less, 8% or less, 7.5% or less, 7% or less, 6.5% or less, and more preferably 6% or less.In addition, BaO raw materials tend to be more expensive than MgO raw materials and CaO raw materials, which adjust the viscosity of glass in the same way as BaO.Therefore, in order to further reduce the cost of raw material batches, the BaO content may be 4% or less, 3% or less, 2.8% or less, 2.7% or less, 2.4% or less, 2.2% or less, 2% or less, or 1.75% or less.

[0049] Na ２ O.K. ２ O and MgO are components that reduce the viscosity of glass and improve the meltability and formability of glass, but if the content of these components is too high, the amount of non-bridging oxygen in the glass matrix increases, and the thermal expansion coefficient of the resulting crystallized glass tends to become high. BaO is also a component that reduces the viscosity of glass and improves the meltability and formability of glass, but if the content of Na is too high, ２ O.K. ２The effect of adding BaO to increase the thermal expansion coefficient is smaller than that of adding O or MgO. Therefore, in order to lower the thermal expansion coefficient of the resulting crystallized glass while improving the meltability and formability of the glass, it is necessary to add BaO in a mass ratio (Na ２ O+K ２ It is preferable to appropriately control the mass ratio (NaO+MgO) / BaO. ２ O+K ２ The ratio (O+MgO) / BaO is preferably 230 or less, 100 or less, 30 or less, 10 or less, 6 or less, 1 or less, 0.8 or less, 0.7 or less, 0.3 or less, 0.2 or less, or 0.1 or less, and more preferably 0.06 or less, and is preferably 0.003 or more, and more preferably 0.01 or more.

[0050] Li ２ O is a component of LAS-based crystals and also a component that reduces the viscosity of glass, improving the meltability and formability of glass. If its content is too high, the liquidus viscosity tends to be too low, making forming difficult. Also, the crystallinity tends to be too strong, making the glass prone to devitrification. As a result, it becomes difficult to obtain desired properties, such as making the crystallized glass prone to breakage. On the other hand, BaO is also a component that reduces the viscosity of glass, improving the meltability and formability of glass, but this effect is limited by the addition of Li. ２ Li tends to be smaller than O. In addition, it has the effect of lowering the liquidus temperature, so it tends to suppress devitrification. Therefore, in order to obtain glass-ceramics having desired properties while suppressing devitrification of the glass and without excessively lowering the liquidus viscosity, it is necessary to use Li. ２ O / BaO(Li ２ It is preferable that the ratio of the content of LiO to the content of BaO is appropriately controlled. ２ O / BaO is preferably 400 or less, 100 or less, 30 or less, 10 or less, 5 or less, 3 or less, 2.5 or less, 2 or less, 1 or less, or 0.9 or less, and more preferably 0.8 or less, and is preferably 0.05 or more, 0.1 or more, or 0.2 or more, and more preferably 0.3 or more.

[0051] MgO is a component that dissolves in LAS-based crystals and increases the thermal expansion coefficient of the LAS-based crystals. Therefore, if the MgO content is too high, the thermal expansion coefficient tends to be high, making it difficult to obtain crystallized glass with excellent thermal shock resistance. In addition, if the crystallization becomes too strong, crystals such as mullite will precipitate, making the glass more likely to devitrify, and the crystallized glass will tend to be more likely to break. The MgO content is preferably 10% or less, 5% or less, 4% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1.2% or less, 1.1% or less, 1% or less, 0.8% or less, 0.6% or less, 0.5% or less, or 0.4% or less, and more preferably 0.3% or less. On the other hand, MgO is an inexpensive raw material and can reduce the viscosity of glass at low cost. Therefore, within the range where an increase in the thermal expansion coefficient is acceptable, adding MgO can reduce the viscosity while suppressing production costs. In addition, MgO is likely to be mixed in as an impurity during glass production, and attempting to completely remove it tends to increase costs. Therefore, the MgO content is preferably 0% or more, 0.001% or more, 0.005% or more, and more preferably 0.01% or more.

[0052] CaO is a component that reduces the viscosity of glass and improves the meltability and formability of glass. It is also a component that adjusts the thermal expansion coefficient and diffuse reflectance of crystallized glass. If the CaO content is too high, the thermal expansion coefficient of the crystallized glass tends to increase. Furthermore, the diffuse reflectance tends to become too high, adversely affecting the design. Therefore, the CaO content is preferably 2% or less, 1.6% or less, 1.4% or less, 1.2% or less, 1% or less, 0.5% or less, 0.2% or less, 0.15% or less, or 0.1% or less, and more preferably 0.075% or less. On the other hand, CaO is likely to be contained in raw materials as an impurity, and attempting to completely remove it tends to increase the cost of the raw material batch. Therefore, the CaO content is preferably 0% or more, 0.001% or more, 0.002% or more, or 0.005% or more, and more preferably 0.01% or more.

[0053] MgO and CaO are components that improve the meltability and formability of glass. On the other hand, if their combined amount is too large, the crystallized glass tends to become cloudy or the thermal expansion coefficient of the crystallized glass tends to increase. Therefore, the MgO + CaO content is preferably 0 to 10%, 1.5 to 5%, 0 to 4%, or 1 to 4%, and more preferably 1 to 3%. Furthermore, MgO and CaO tend to be cheaper than the BaO raw material, which adjusts the viscosity of the glass like MgO and CaO. Therefore, to further reduce the cost of the raw material batch, MgO and CaO may be added while controlling the BaO content to improve the meltability and formability of the glass. Therefore, the content of BaO is preferably 4% or less, 3% or less, 2.8% or less, 2.7% or less, 2.5% or less, 2.4% or less, 2.2% or less, 2% or less, or 1.75% or less, and in this case, the content of MgO+CaO is preferably 0% or more, 0.01% or more, 0.1% or more, 0.4% or more, 0.7% or more, 1% or more, or 1.5% or more, and is preferably 10% or less, 5% or less, 4% or less, 3% or less, 2.5% or less, 2% or less, or 1.9% or less.

[0054] TiO ２ is a nucleation component for precipitating crystals in the crystallization process. ２ The content of TiO is 0.2% or more, preferably 1% or more, 1.2% or more, 1.4% or more, and more preferably 1.5% or more. ２ If the content of ZrO is too low, crystal nuclei do not precipitate sufficiently in the crystallization step, surface crystallization tends to occur, and the strength of the crystallized glass tends to be low. On the other hand, if the content of ZrO is too high, the coloring of the glass becomes significantly stronger. ２ and TiO ２ The zirconia titanate crystals containing SiO act as crystal nuclei, but electrons transition from the valence band of the oxygen ligand to the conduction band of the central metals zirconium and titanium (LMCT transition), which contributes to the coloring of the crystallized glass. ２An LMCT transition can occur from the valence band of the framework to the conduction band of tetravalent titanium in the residual glass phase. In addition, a dd transition occurs in the trivalent titanium in the residual glass phase, which contributes to the coloring of the glass-ceramic. Furthermore, when titanium and iron coexist, ilmenite (FeTiO ３ It is also known that when titanium and tin coexist, the yellow color becomes stronger. ２ The content is preferably 5% or less, 4% or less, 3.9% or less, 3.8% or less, 3% or less, 2.6% or less, 2.5% or less, 2.4% or less, 2.2% or less, 2.1% or less, 2% or less, or 1.95% or less, and more preferably 1.9% or less.

[0055] ZrO ２ is a nucleation component for precipitating crystals in the crystallization process. ２ If the content of ZrO is too small, crystal nuclei are not sufficiently formed and coarse crystals tend to precipitate, so that the crystallized glass is prone to surface crystallization and breakage. ２ The content of ZrO is preferably 0% or more, 0.5% or more, 1% or more, 1.3% or more, 1.4% or more, 1.5% or more, or 1.8% or more, and more preferably 2% or more. ２ If the content is too high, coarse ZrO ２ Crystals precipitate, the glass becomes more susceptible to devitrification, and the crystallized glass becomes more susceptible to breakage. ２ The content is preferably 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.9% or less, and more preferably 2.8% or less.

[0056] P ２ O ５ affects the precipitation of crystals, resulting in the formation of coarse ZrO ２ It is a component that suppresses crystal precipitation. ２ O ５ By containing P, the transmittance of the crystallized glass tends to be improved and the thermal expansion coefficient of the crystallized glass tends to be reduced. ２ O ５ If the content is too low, coarse ZrO ２Crystals may precipitate, causing the glass to devitrify and making the crystallized glass more susceptible to breakage. In addition, it may become difficult to obtain the desired thermal properties. ２ O ５ The content of is preferably 0% or more, 0.01% or more, 0.1% or more, 0.2% or more, 0.3%, 0.5% or more, 0.8% or more, and more preferably 1% or more. ２ O ５ If the content of P is too high, crystallization tends to be suppressed too much, and it may be difficult to obtain the desired thermal properties. ２ O ５ The raw material price of P is high, and the raw material cost tends to increase as the content increases. ２ O ５ The content is preferably 5% or less, 4% or less, 3% or less, 2.5% or less, 2% or less, 1.8% or less, and more preferably 1.6% or less.

[0057] ZnO, like BaO, is a component that reduces the viscosity of glass and improves the melting and molding properties of glass. It is also a component that adjusts the thermal expansion coefficient and refractive index of glass-ceramics. If the content of ZnO is too high, crystals containing Zn will precipitate, making the glass more likely to devitrify and break. ZnO also contributes to the reduction of Li ２ ZnO tends to be more expensive than raw materials containing other components other than O, and therefore the inclusion of ZnO tends to increase the cost of the raw material batch. Therefore, the ZnO content is preferably 10% or less, 8% or less, 6% or less, 4% or less, 3% or less, 2% or less, less than 1.1%, 1% or less, 0.8% or less, 0.6% or less, 0.4% or less, 0.2% or less, 0.1% or less, and more preferably 0.05% or less.

[0058] SnO ２ is a component that acts as a clarifier. It can also be a component that efficiently precipitates crystals in the crystallization process. ２ If the content of SnO is too small, it becomes difficult to refine the glass, and productivity tends to decrease. ２The content of SnO is preferably 0% or more, 0.01% or more, 0.1% or more, 0.15% or more, and more preferably 0.2% or more. ２ If the content is too high, the coloring of the crystallized glass may become strong, and SnO may be generated during glass melting. ２ The amount of evaporation of SnO increases. ２ The evaporated product of SnO tends to scatter and pollute the environment. ２ The content is 3% or less, preferably 2% or less, and more preferably 1.5% or less.

[0059] (Li ２ O+MgO+CaO+ZnO+TiO ２ )-(Na ２ O+K ２ O) (parameter a) is a value that mainly affects the total light transmittance of the crystallized glass in the visible light region. If this value is large, the total light transmittance in the visible light region of the crystallized glass in which β-spodumene solid solution has been precipitated tends to be low. In other words, if this value is too large, the opacity of the appearance of the crystallized glass obtained is emphasized, resulting in a lack of luxury, which may ultimately impair the design. Infrared transmittance also tends to be low. Therefore, 20% or less, 15% or less, 10% or less, 9% or less, 8.5% or less, 8% or less, or 7.5% or less is preferred, and 7% or less is more preferred. On the other hand, if this value is small, the total light transmittance in the visible light region of the crystallized glass tends to be high, and the back side tends to be visible. Therefore, the above value is preferably 0% or more, 2% or more, 3% or more, 3.5% or more, 4% or more, 4.5% or more, 5% or more, or 5.2% or more, and more preferably 5.3% or more. Therefore, for example, in order to achieve a total light transmittance of 10 to 50% in order to improve the design, the parameter a is preferably 3.5 to 7%.

[0060] Al ２ O ３ +BaO+4(SrO+ZnO)+8(CaO+Li ２O) (parameter b) is a value that mainly affects the transmittance of crystallized glass in the infrared region. If this value is high, the transmittance of the resulting crystallized glass in the infrared region tends to be low. That is, it becomes difficult to use it in applications that require infrared transmission, such as temperature sensors that use infrared rays or applications for protecting infrared cameras. Therefore, the above value is preferably 80% or less, 70% or less, 67% or less, 65% or less, 62% or less, 60% or less, 58% or less, or 56% or less, and particularly preferably 55% or less. Therefore, for example, to achieve a total light transmittance of 20% or more at a wavelength of 1500 nm, parameter b is preferably 67% or less. On the other hand, if the above value is too low, too much infrared light will be transmitted, making it undesirable for applications requiring thermal insulation. In addition, the transmittance of visible light also tends to be high, which may result in a decrease in design, such as a change in appearance from white to cream. Therefore, for example, 10.8% or more, 20% or more, 30% or more, 40% or more, 45% or more, 46% or more, 48% or more is preferable, and 50% or more is particularly preferable. Therefore, for example, in order to realize a total light transmittance of 90% or less at a wavelength of 1500 nm, the parameter b is preferably 40% or more.

[0061] Al ２ O ３ -(Li ２ O+MgO)+2(CaO+SrO+P ２ O ５ )-2(TiO ２ + ZrO ２ ) + 3 (Na ２ O+K ２ O)-6SnO ２ Parameter c is a value that affects the thermal expansion coefficient of the crystallized glass. If this value is high, the thermal expansion coefficient of the crystallized glass obtained tends to be too high. Therefore, the above value is preferably 40% or less, 30% or less, 25% or less, 23% or less, 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, and more preferably 15% or less. Therefore, for example, the absolute value of the thermal expansion coefficient of the crystallized glass at 30 to 750°C is 25 x 10 －７ / °C or less, parameter c is preferably 18% or less. On the other hand, if this value is too low, the viscosity at high temperatures will be too high, or the glass will be more susceptible to breakage during crystallization, which tends to have adverse effects on productivity and properties. Therefore, the above value is preferably 0% or more, 5% or more, 7% or more, 9% or more, 10% or more, 10.3% or more, or 10.5% or more, and more preferably 10.7% or more. Furthermore, if this value is low, the thermal expansion coefficient of the resulting crystallized glass tends to be small. When used as a composite material by bonding with other materials, if the difference in thermal expansion coefficient between the materials to be bonded is too large, problems may arise such as the composite member being easily deformed by temperature changes. Therefore, in such applications, for example, the absolute value of the thermal expansion coefficient at 30 to 750°C should be 5 x 10 －７ / °C or more, in which case the parameter c is preferably set to, for example, 9% or more.

[0062] Al ２ O ３ +ZnO+P ２ O ５ +2(MgO+CaO+BaO+ZrO ２ ) + 4TiO ２ +10Na ２ O (parameter d) is a value that affects the dielectric loss of the crystallized glass. If this value is large, the dielectric loss of the resulting crystallized glass tends to be too large. Therefore, the above value is preferably 65% ​​or less, 55% or less, 52% or less, 50% or less, 48% or less, 47% or less, 46% or less, 45% or less, 44% or less, 43% or less, and particularly preferably 42% or less. If this value is too low, the viscosity of the glass will increase or the batch cost will increase, adversely affecting productivity. Therefore, the above value is preferably 10% or more, 20% or more, 25% or more, 30% or more, 35% or more, 38% or more, 39% or more, and particularly preferably 40% or more. Therefore, for example, while maintaining productivity, the dielectric loss value of the crystallized glass at 2.45 GHz can be increased to 40 x 10 －３ To achieve a temperature of 1000 K or less, the parameter d is preferably 35 to 50%.

[0063] SrO is a component that reduces the viscosity of glass and improves its meltability and formability. It is also a component that adjusts the thermal expansion coefficient and refractive index of crystallized glass. If the SrO content is too high, the glass is prone to devitrification and breakage. Furthermore, SrO is expensive, and adding a large amount tends to increase raw material costs. Therefore, the SrO content is not particularly limited, but is preferably 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, or 0.5% or less, and more preferably 0.1% or less. However, since SrO is easily mixed in as an impurity, attempting to completely remove SrO tends to increase the cost of the raw material batch. To suppress an increase in the cost of the raw material batch, the lower limit of the SrO content is preferably 0.0001% or more, more preferably 0.0003% or more, and more preferably 0.0005% or more.

[0064] PbO is highly toxic and may pollute the environment during the glass manufacturing process, waste glass treatment, etc. Therefore, the PbO content is preferably 2% or less, 1% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less, and it is particularly preferable that PbO is substantially absent (specifically, less than 0.1% by mass). Note that PbO may be contained within a range in which its impact on the environment during the glass manufacturing process or waste glass treatment is negligible, and in that case, it can function as a colorant, an additive for reducing viscosity, or the like.

[0065] As ２ O ３ and Sb ２ O ３ As is highly toxic and may pollute the environment during the glass manufacturing process, waste glass treatment, etc. Therefore, these components are preferably contained in an amount of 2% or less, 1% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less, respectively, and it is particularly preferable that they are not contained substantially (specifically, less than 0.1% by mass). Note that, within a range where the impact on the environment during the glass manufacturing process or waste glass treatment can be ignored, As ２ O３ and Sb ２ O ３ These components can function as a clarifier, a nucleating agent, or the like.

[0066] Fe ２ O ３ is a component that enhances the coloring of glass, especially TiO ２ and SnO ２ Therefore, in order to suppress the coloring of the glass-ceramics, Fe is a component that significantly intensifies the coloring due to its interaction with Fe. ２ O ３ The content of is preferably 20,000 ppm or less, 10,000 ppm or less, less than 5,000 ppm, less than 3,000 ppm, 2,000 ppm or less, 1,000 ppm or less, less than 900 ppm, 700 ppm or less, 500 ppm or less, 300 ppm or less, 200 ppm or less, 100 ppm or less, 95 ppm or less, 85 ppm or less, and more preferably 80 ppm or less. ２ O ３ is easily mixed in as an impurity, ２ O ３ If an attempt is made to completely remove Fe, the cost of the raw material batch tends to increase. ２ O ３ The lower limit of the content is preferably 0 ppm or more, 0.001 ppm or more, 0.01 ppm or more, 0.1 ppm or more, 1 ppm or more, 10 ppm or more, or 30 ppm or more, and more preferably 40 ppm or more.

[0067] V ２ O ５ is a component that affects the color of the crystallized glass in trace amounts. ２ O ５ If the content of V is too high, it becomes difficult to obtain LAS crystallized glass having excellent transparency. ２ O ５ The content of is preferably 10,000 ppm or less, 5,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 100 ppm or less, and more preferably 50 ppm or less. ２ O ５Since V can be mixed in as an impurity in the raw materials, completely eliminating it would likely increase the raw material costs. ２ O ５ The content is preferably 0 ppm or more, 0.001 ppm or more, 0.01 ppm or more, 0.05 ppm or more, 0.1 ppm or more, or 0.5 ppm or more, and more preferably 1 ppm or more.

[0068] Pt is a component that can be mixed into glass in the form of ions, colloids, metal, etc., and causes a yellow to brown coloration. This tendency becomes more pronounced after crystallization. For this reason, the Pt content is preferably 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, or 2 ppm or less, and more preferably 1 ppm or less. While Pt contamination should be avoided as much as possible, when using general melting equipment, the use of Pt components may be necessary to obtain homogeneous glass. For this reason, attempting to completely remove Pt tends to increase production costs. In cases where coloring is not adversely affected, in order to suppress an increase in manufacturing costs, the lower limit of the Pt content is preferably 0.0001 ppm or more, 0.001 ppm or more, 0.01 ppm or more, 0.02 ppm or more, 0.03 ppm or more, 0.04 ppm or more, 0.05 ppm or more, 0.06 ppm or more, and more preferably 0.07 ppm or more. In cases where coloring is permitted, Pt may be added to ZrO ２ and TiO ２ Similarly, Pt may be used as a nucleating agent to promote the precipitation of the main crystals. In this case, Pt may be used alone as a nucleating agent, or may be used in combination with other components as a nucleating agent. When Pt is used as a nucleating agent, the form of the nucleating agent is not particularly important (colloid, metal crystal, etc.).

[0069] Rh is a component that can be mixed into glass in the form of ions, colloids, metal, etc., and, like Pt, tends to cause yellow to brown coloration. Therefore, the Rh content is preferably 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, and more preferably 0.3 ppm or less. Although Rh contamination should be avoided as much as possible, when using general melting equipment, the use of Rh components may be necessary to obtain homogeneous glass. Therefore, attempting to completely remove Rh tends to increase production costs. In the case where coloring is not adversely affected, in order to suppress an increase in production costs, the lower limit of the Rh content is preferably 0.0001 ppm or more, 0.001 ppm or more, 0.01 ppm or more, 0.02 ppm or more, 0.03 ppm or more, 0.04 ppm or more, 0.05 ppm or more, or 0.06 ppm or more, and more preferably 0.07 ppm or more. In the case where coloring is permitted, Rh may be added to ZrO ２ and TiO ２ In this case, Rh may be used as a nucleating agent alone, or may be used in combination with other components. When Rh is used as a nucleating agent to promote the precipitation of primary crystals, the form of Rh is not particularly important (colloid, metal crystal, etc.).

[0070] Furthermore, the Pt+Rh content (the total amount of Pt and Rh) is preferably 7 ppm or less, 3 ppm or less, less than 1 ppm, less than 0.9 ppm, less than 0.8 ppm, less than 0.7 ppm, less than 0.6 ppm, less than 0.5 ppm, or less than 0.4 ppm, and more preferably 0.3 ppm or less. While mixing of Pt and Rh should be avoided as much as possible, when using general melting equipment, it may be necessary to use Pt components, Rh components, or Pt-Rh alloy components to obtain homogeneous glass. Therefore, completely removing Pt and Rh tends to increase production costs. In the case where coloring is not adversely affected, in order to suppress an increase in production costs, the lower limit of Pt+Rh is preferably 0.0001 ppm or more, 0.001 ppm or more, 0.01 ppm or more, 0.02 ppm or more, 0.03 ppm or more, 0.04 ppm or more, 0.05 ppm or more, or 0.06 ppm or more, and more preferably 0.07 ppm or more.

[0071] Pr ６ O １１ is a component that affects the absorption in the infrared region and the thermal expansion coefficient in LAS crystallized glass. ６ O １１ By adding an appropriate amount of Pr, it is possible to adjust the transmittance in the wavelength range of about 1300 to 2300 nm, and it can be used as glass for adjusting the amount of light in, for example, an optical sensor. Furthermore, when comparing glasses with similar compositions, Pr ６ O １１ The larger the amount of Pr added, the lower the thermal expansion coefficient of the crystallized glass at 30 to 380°C tends to be. ６ O １１ The content of Pr is preferably 0 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 10 ppm or more, or 30 ppm or more. On the other hand, if added in excess, light absorption in the infrared region may become too large, and when used in products equipped with optical temperature sensors, etc., light may become less transmittable in a specific wavelength region, which may cause malfunction. Therefore, Pr ６ O １１The content is preferably 2000 ppm or less, 1000 ppm or less, 500 ppm or less, 200 ppm or less, or 100 ppm or less, and more preferably 50 ppm or less.

[0072] Sm ２ O ３ Although Sm is an element that is likely to be mixed in as an impurity, even if it is mixed in in small amounts, it tends not to change the properties of the LAS crystallized glass of the present invention. ２ O ３ If we try to completely eliminate Sm, the cost of the raw material batch will likely increase. ２ O ３ The content of Sm is preferably 0 ppm or more, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 10 ppm or more, or 30 ppm or more. On the other hand, if added in excess, the crystallized glass may be strongly colored, impairing the design properties. ２ O ３ The content is preferably 2000 ppm or less, 1000 ppm or less, 500 ppm or less, 200 ppm or less, or 100 ppm or less, and more preferably 50 ppm or less.

[0073] The crystallized glass of the present invention may contain, in addition to the above components, e.g., H, as long as it does not adversely affect the thermal properties and transparency. ２ , CO ２ , CO, H ２ O, He, Ne, Ar, N ２Trace components such as Ag, Au, Pd, Ir, Cr, Sc, Ce, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, etc. may be contained up to 0.1% each. Furthermore, intentional addition of Ag, Au, Pd, Ir, Cr, Sc, Ce, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, etc. tends to increase the cost of the raw material batch, but when glass containing Ag, Au, etc. is subjected to light irradiation or heat treatment, aggregates of these components are formed, which can serve as the starting point for promoting crystallization. Furthermore, Pd, etc., have various catalytic effects, and by adding them, it is possible to impart unique functions to the crystallized glass. In view of these circumstances, when the purpose is to promote crystallization or to impart other functions, the above components may be contained in an amount of 1% or less, 0.5% or less, 0.3% or less, or 0.1% or less, respectively; otherwise, it is preferable that the amount is 500 ppm or less, 300 ppm or less, 100 ppm or less, and particularly 10 ppm or less.

[0074] Furthermore, the crystallized glass of the present invention may contain MoO as long as it does not adversely affect the thermal properties and transparency. ３ , S.O. ３ , MnO, Cl ２ , Y ２ O ３ , La ２ O ３ , W.O. ３ , HfO ２ , Ta ２ O ５ , Nd ２ O ３ , Nb ２ O ５ , RfO ２ However, since the raw material batches of the above components are expensive and tend to increase the manufacturing cost, they may not be added unless there are special circumstances. ２ is expensive, and Ta ２ O ５ Since these components may be conflict minerals, the total amount of these components is preferably 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, 0.05% or less, less than 0.05%, 0.049% or less, 0.048% or less, 0.047% or less, 0.046% or less, and more preferably 0.045% or less.

[0075] The preferred composition range of the LAS-based crystallized glass of the present invention is SiO ２ 55-70%, Al ２ O ３ 15-30%, Li ２ O 0.1-3.47%, BaO 2-10%, MgO 0-10%, TiO ２ 0.2-5%, ZrO ２ 0 to 5%, parameter a 3 to 10%, parameter b 30 to 70%, parameter c 25% or less, and parameter d 45% or less. Alternatively, the preferred composition range of the LAS-type crystallized glass of the present invention is SiO ２ 55-75%, Al ２ O ３ 15-30%, Li ２ O 2-3.49%, BaO 0-10%, MgO 0-0.8%, CaO 0-1.6%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３ 30-2000ppm, V ２ O ５ 0 to 0.1%, parameter a is 3 to 10%, parameter b is 30 to 70%, parameter c is 25% or less, and parameter d is 45% or less. Alternatively, the LAS-type crystallized glass of the present invention preferably has a composition range of SiO ２ 55-75%, Al ２ O ３ 15-30%, Li ２ O 2.0-3.49%, BaO 2.7-10%, MgO+CaO 0-1.9%, TiO ２ 0.2-5%, ZrO ２ 1.4-5% Fe ２ O ３ The LAS-type crystallized glass of the present invention preferably contains 30 to 10,000 ppm of SiO, parameter a is 3 to 10%, parameter b is 30 to 70%, parameter c is 25% or less, and parameter d is 45% or less. ２ 55-75%, Al ２ O ３15-30%, Li ２ O 2.0-3.5%, Na ２ O+K ２ O > 0~0.9%, BaO 2.6~10%, MgO+CaO 0~5%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３ The LAS-type crystallized glass of the present invention preferably contains 30 to 10,000 ppm of SiO, parameter a is 3 to 10%, parameter b is 30 to 70%, parameter c is 25% or less, and parameter d is 45% or less. ２ 55-68%, Al ２ O ３ 20-30%, Li ２ O 2.0-3.49%, Na ２ O+K ２ O 0-0.5%, BaO 0-2.7%, MgO+CaO 0-2.5%, TiO ２ 0.2-3.9%, ZrO ２ 1.4-2.9%, P ２ O ５ 0-2.5% Fe ２ O ３ The LAS-type crystallized glass of the present invention preferably contains 30 to less than 900 ppm of SiO, parameter a is 3 to 8.5%, parameter b is 30 to 70%, parameter c is 25% or less, and parameter d is 45% or less. ２ 55-75%, Al ２ O ３ 10-35%, Li ２ O 0.1-3.47%, BaO 2-10%, MgO 0-10%, TiO ２ 0-5% ZrO ２ 0-5%, P ２ O ５ 0-5%, Pr ６ O １１The content is 10 to 500 ppm, parameter a is 5.2 to 8%, parameter b is 5 to 55%, parameter c is 5 to 15%, and parameter d is 30 to 45%. Here, a, b, c, and d are the conditions shown below. a: (Li ２ O+MgO+CaO+ZnO+TiO ２ )-(Na ２ O+K ２ O) b: Al ２ O ３ +BaO+4(SrO+ZnO)+8(CaO+Li ２ O) c: Al ２ O ３ -(Li ２ O+MgO)+2(CaO+SrO+P ２ O ５ )-2(TiO ２ + ZrO ２ ) + 3 (Na ２ O+K ２ O)-6SnO ２ d: Al ２ O ３ +ZnO+P ２ O ５ +2(MgO+CaO+BaO+ZrO ２ ) + 4TiO ２ +10Na ２ O

[0076] By having the above composition, it becomes easier to obtain an LAS-based crystallized glass having a low thermal expansion coefficient, excellent dielectric loss characteristics, and reduced raw material batch costs.

[0077] The β-OH value has a significant effect on the low-temperature viscosity and crystallization of glass. The β-OH value is preferably 0.01 / mm or more, 0.02 / mm or more, 0.04 / mm or more, or 0.06 / mm or more, and more preferably 0.08 / mm or more. If the β-OH value is within the above range, the low-temperature viscosity decreases and the crystallization rate tends to increase, thereby improving production efficiency. On the other hand, if the β-OH value is too high, bubbles tend to form at the interface with the metal components used in glass melting, which tends to reduce the quality of the glass product. Furthermore, depending on the composition, the crystallization rate may become too high, resulting in the precipitation and growth of other crystal species that normally do not precipitate or precipitate in very small amounts. As a result, the desired thermal properties may not be achieved. Therefore, the β-OH value is preferably 2 / mm or less, 1.5 / mm or less, 1 / mm or less, 0.8 / mm or less, 0.7 / mm or less, or 0.6 / mm or less, and more preferably 0.5 / mm or less. The β-OH value varies depending on the raw materials used, the melting atmosphere, the melting temperature, the melting time, etc., and can be adjusted by changing these conditions as necessary. For example, the β-OH value can be increased by increasing the amount of hydroxide in the raw materials, melting by heating with a burner, or raising the melting temperature. Furthermore, the β-OH value can be increased by extending the melting time in a sealed environment and by shortening the melting time in an unsealed environment.

[0078] The LAS-based crystallized glass of the present invention has a glass transition temperature T ｇ The glass transition temperature (the temperature at which the slope of the thermal expansion curve of the glass changes) is preferably 650° C. or higher, 670° C. or higher, 700° C. or higher, 710° C. or higher, 720° C. or higher, or 730° C. or higher, and more preferably 735° C. or higher. If the glass transition temperature is too low, the glass will flow too much when heated, making it difficult to form into a desired shape.

[0079] The LAS-based crystallized glass of the present invention has a yield point T ｆThe yield point (the temperature at which the slope of the thermal expansion curve of the glass changes at temperatures equal to or higher than the glass transition temperature) is preferably 700° C. or higher, 730° C. or higher, 760° C. or higher, or 780° C. or higher, and more preferably 790° C. or higher. If the yield point is too low, the glass will flow too much when heated, making it difficult to form into a desired shape.

[0080] The LAS-based crystallized glass of the present invention has a viscosity of about 10 ４ The temperature corresponding to the viscosity of dPa s is preferably 1400°C or less, 1390°C or less, 1380°C or less, 1375°C or less, 1370°C or less, or 1365°C or less, and more preferably 1360°C or less. If the temperature is too high, the meltability of the glass decreases and it becomes difficult to refine, so productivity tends to decrease. Furthermore, there is a tendency for a load to be applied to the molding member, so productivity tends to decrease.

[0081] The LAS-based crystallized glass of the present invention has a glass viscosity of about 10 ３．５ The temperature corresponding to the viscosity of dPa s is preferably 1500°C or less, 1490°C or less, 1480°C or less, 1470°C or less, 1460°C or less, or 1450°C or less, and more preferably 1445°C or less. If the temperature is too high, the meltability of the glass decreases and it becomes difficult to refine, so productivity tends to decrease. Furthermore, there is a tendency for a load to be applied to the molding member, so productivity tends to decrease.

[0082] The LAS-based crystallized glass of the present invention has a glass viscosity of about 10 ３ The temperature corresponding to the viscosity of dPa s is preferably 1600°C or less, 1590°C or less, 1580°C or less, 1570°C or less, 1560°C or less, 1550°C or less, or 1545°C or less, and more preferably 1540°C or less. If the temperature is too high, the meltability of the glass decreases and it becomes difficult to refine, so productivity tends to decrease. Furthermore, there is a tendency for a load to be applied to the molding member, so productivity tends to decrease.

[0083] The LAS-based crystallized glass of the present invention has a glass viscosity of about 10 ２．５The temperature corresponding to the viscosity in dPa s is preferably 1700° C. or less, 1690° C. or less, 1680° C. or less, 1670° C. or less, 1660° C. or less, or 1655° C. or less, and more preferably 1650° C. or less. If the temperature is too high, the meltability of the glass decreases and fining becomes difficult, which tends to reduce productivity.

[0084] The LAS-based crystallized glass of the present invention has a liquidus temperature (T Ｌ ) is preferably 1530°C or less, 1500°C or less, 1480°C or less, 1460°C or less, 1440°C or less, 1420°C or less, particularly preferably 1410°C or less. If the liquidus temperature is too high, devitrification is likely to occur during production. On the other hand, if it is 1480°C or less, production by a roll method or the like is facilitated, if it is 1450°C or less, production by a casting method or the like is facilitated, and if it is 1410°C or less, production by a fusion method or the like is facilitated.

[0085] The LAS-based crystallized glass of the present invention preferably has a liquidus viscosity (logarithm of viscosity corresponding to the liquidus temperature, logη) of 2.90 or more, 3.20 or more, 3.50 or more, particularly 3.70 or more. If the liquidus viscosity is too low, devitrification tends to occur during production. On the other hand, if it is 3.40 or more, it becomes easy to produce it by a roll method or the like, if it is 3.50 or more, it becomes easy to produce it by a casting method or the like, and if it is 3.70 or more, it becomes easy to produce it by a fusion method or the like.

[0086] In the LAS-based crystallized glass of the present invention, it is preferable that β-spodumene solid solution is precipitated as the main crystal. Precipitating β-spodumene solid solution as the main crystal makes it easy to obtain an LAS-based crystallized glass with a small thermal expansion coefficient and excellent dielectric loss characteristics. The LAS-based crystallized glass of the present invention may contain sub-crystals such as β-quartz solid solution, as long as there is no adverse effect on coloration or dielectric loss characteristics. However, since crystallized glass containing β-quartz solid solution tends to have high dielectric loss characteristics, it is preferable, unless there are special circumstances, to convert as much of the β-quartz solid solution as possible to β-spodumene solid solution, thereby eliminating the β-quartz solid solution.

[0087] The LAS-based crystallized glass of the present invention has a density of 2.40 to 2.80 g / cm３ , 2.42-2.78g / cm ３ , 2.44-2.76g / cm ３ , 2.46-2.74g / cm ３ , particularly 2.47 to 2.73 g / cm ３ It is preferable that the density of the crystallized glass is too low, the gas permeability of the crystallized glass may increase. On the other hand, if the density of the crystallized glass is too high, the weight per unit area increases, making it difficult to handle. The density of the crystallized glass is also an index for determining whether the glass is sufficiently crystallized. Specifically, for the same glass, the higher the density (the greater the density difference between the glass before crystallization and the crystallized glass), the more the crystallization has progressed.

[0088] The LAS crystallized glass of the present invention has an absolute value of the thermal expansion coefficient of 30×10 at 30 to 750°C. －７ / ℃ or less, 28 x 10 －７ / ℃ or less, 25 × 10 －７ / ℃ or less, 22 × 10 －７ / ℃ or less, 20 x 10 －７ / ℃ or less, 18 x 10 －７ / ℃ or less, 16 x 10 －７ / ℃ or less, 14 × 10 －７ / ℃ or less, 13 × 10 －７ / °C or less is preferred.

[0089] The LAS crystallized glass of the present invention has an absolute value of the thermal expansion coefficient of 30×10 at 30 to 380°C. －７ / ℃ or less, 28 x 10 －７ / ℃ or less, 25 x 10 －７ / ℃ or less, 22 × 10 －７ / ℃ or less, 20 x 10 －７ / ℃ or less, 18 x 10 －７ / ℃ or less, 16 x 10 －７ / ℃ or less, 14 × 10 －７ / ℃ or less, 13 × 10 －７ / °C or less is preferred.

[0090] If the absolute value of the thermal expansion coefficient is too high, the thermal shock resistance will be low and it will be difficult to use at high temperatures. It will also be difficult to apply to applications that require positional stability. In particular, when it is expected to be used as a cooking top plate, a low absolute value of the thermal expansion coefficient is preferable to avoid damage due to heat or distortion. There is no particular upper limit on the absolute value of the thermal expansion coefficient, but in reality, it is 50 x 10 at 30 to 750°C and 30 to 380°C. －７ / ℃.

[0091] The LAS crystallized glass of the present invention has a total light transmittance of L ＊ Preferably, the value is 50 or less, 35 or less, 20 or less, and particularly 15 or less. If this value is too large, for example, in the application of a top plate for a cooker, the internal structure tends to be easily visible, and the design tends to be lost. On the other hand, if this value is too low, the opacity is emphasized, resulting in an appearance lacking in luxury, which may result in a loss of design. Therefore, the L of the total light transmittance ＊ The value is preferably 5 or more, particularly 10 or more.

[0092] The LAS crystallized glass of the present invention has a total light transmittance of a ＊ The value is preferably within ±5, ±3, ±2, ±1, or ±0.6, and more preferably within ±0.5. If this value is too large in the negative direction, the color tends to appear green, and if it is too large in the positive direction, the color tends to appear red.

[0093] The LAS crystallized glass of the present invention has a total light transmittance of b ＊ The value is preferably within ±20, ±10, ±6.5, ±5.5, or ±5, and more preferably within ±4.5. If this value is too large in the negative direction, the color tends to appear blue, and if it is too large in the positive direction, the color tends to appear yellow.

[0094] The LAS crystallized glass of the present invention preferably has a total light transmittance of 10% or more, 20% or more, 30% or more, 40% or more, particularly 50% or more at a wavelength of 1500 nm and a thickness of 4 mm. If this value is too small, for example, in applications such as an induction cooker top plate where temperature is measured using an infrared optical sensor, light in a specific wavelength range may be difficult to transmit, potentially causing the sensor to malfunction.

[0095] The LAS crystallized glass of the present invention has a diffuse reflectance of L ＊ The value is preferably at least 60, at least 70, at least 80, at least 85, and particularly preferably at least 90. If this value is too small, the appearance of the crystallized glass will no longer be white, and the design will tend to be lost.

[0096] The LAS crystallized glass of the present invention has a diffuse reflectance of a ＊ The value is preferably within ±10, ±8, ±6, or ±4, and particularly preferably within ±2. If this value is too large in the negative direction, the color tends to appear green, and if it is too large in the positive direction, the color tends to appear red.

[0097] The LAS crystallized glass of the present invention has a diffuse reflectance of b ＊ The value is preferably within ±10, ±8, ±6, or ±4, and particularly preferably within ±2. If this value is too large in the negative direction, the image tends to appear blue, and if it is too large in the positive direction, the image tends to appear yellow.

[0098] The LAS crystallized glass of the present invention preferably has a dielectric constant value of 10 or less, 8 or less, particularly 7 or less at 2.45 GHz. If this value is too large, it becomes difficult to use in some applications requiring low dielectric loss characteristics, such as microwave oven trays. Specifically, in the case of microwave oven trays, the tray may absorb microwaves during use, which may cause a decrease in heating efficiency or damage to the tray. The lower limit of the dielectric loss is not particularly limited, but is, for example, 1 or more.

[0099] The LAS crystallized glass of the present invention preferably has a tanδ value of 0.1 or less, 0.05 or less, and particularly 0.01 or less at 2.45 GHz. If this value is too large, it becomes difficult to use it in some applications that require low dielectric loss characteristics, such as microwave oven trays. Specifically, in the case of microwave oven trays, the tray may absorb microwaves during use, which may cause a decrease in heating efficiency or damage to the tray. The lower limit of the dielectric loss is not particularly limited, but is, for example, 0.001 or more.

[0100] The LAS crystallized glass of the present invention has a dielectric loss value of 50×10 at 2.45 GHz. －３ Below, 45 x 10 －３ Below, 40 x 10 －３ Below, 35 x 10 －３ Below, 30 x 10 －３ Below, 25 x 10 －３ Below, especially 20 x 10 －３ It is preferable that the dielectric loss is not more than 0.0001. If this value is too large, it becomes difficult to use it in some applications that require low dielectric loss characteristics, such as microwave oven trays. Specifically, in the case of microwave oven trays, the tray may absorb microwaves during use, which may cause a decrease in heating efficiency or damage to the tray. There are no particular restrictions on the lower limit of the dielectric loss, but it is, for example, 0.0001 or more.

[0101] The LAS-based crystallized glass of the present invention may be subjected to chemical strengthening or the like. The conditions for chemical strengthening treatment may be appropriately selected by taking into consideration the glass composition, the volume fraction of the crystalline phase and the residual glass phase, the type of molten salt, etc., and the treatment time and treatment temperature. For example, in order to facilitate chemical strengthening, Na, which may be contained in the residual glass phase, may be added. ２A glass composition containing a large amount of O may be selected. The molten salt may contain monovalent cations such as Li, Na, and K, or divalent cations such as Mg, Ba, Zn, Ca, and Sr, either singly or in combination. Furthermore, in addition to the usual single-stage strengthening, multi-stage chemical strengthening may be selected. Examples of molten salts that can be used include nitrates (potassium nitrate, sodium nitrate, lithium nitrate, etc.), carbonates (potassium carbonate, sodium carbonate, lithium carbonate, etc.), sulfates (potassium sulfate, sodium sulfate, lithium sulfate, etc.), chlorides (potassium chloride, sodium chloride, lithium chloride, etc.), and combinations thereof. Nitrates with low melting points are preferred, with sodium nitrate being particularly preferred. The ion exchange temperature is preferably 330 to 550°C, 350 to 500°C, and particularly 390 to 450°C. The ion exchange time is preferably 30 minutes to 12 hours, or 45 minutes to 10 hours. The above strengthening conditions may be changed as desired depending on the required application and strength, and the preferred conditions are not necessarily limited to those described above.

[0102] Next, the method for producing the crystallized glass of the present invention will be described.

[0103] First, a raw material batch prepared to obtain glass of the above composition is charged into a glass melting furnace, melted at 1200 to 1800° C., and then formed. When melting the glass, any one of the following melting methods may be used, or two or more of them may be combined: a flame melting method using a burner or the like, an electric melting method using electrical heating, a melting method using laser irradiation, a melting method using plasma, a liquid phase synthesis method, and a vapor phase synthesis method.

[0104] The forming method is preferably any one of the overflow method, float method, downdraw method, slot-down method, redraw method, containerless method, blow method, press method, roll method, bushing method, tube drawing method, etc., or a combination of two or more of these forming methods. Furthermore, the formed glass may be reheated at a temperature equal to or higher than the glass transition point. In this way, glass with good surface quality can be produced.

[0105] Next, the resulting crystallizable glass (crystallizable glass before crystallization) is heat-treated to crystallize. Crystallization conditions include first nucleation at 700-950°C (preferably 750-900°C) for 0.1-100 hours (preferably 1-60 hours), followed by crystal growth at 800-1050°C (preferably 800-1000°C) for 0.1-50 hours (preferably 0.2-10 hours), and then transformation from β-quartz solid solution to β-spodumene solid solution at 1000-1300°C (preferably 1050-1200°C) for 0.1-50 hours (preferably 0.2-10 hours). In this way, white LAS-based crystallized glass in which β-spodumene solid solution crystals are precipitated as the primary crystals can be obtained. Heat treatment can be performed at only a specific temperature or at two levels, or at three or more levels, or by heating while applying a temperature gradient.

[0106] Crystallization may also be promoted by applying or irradiating sound waves or electromagnetic waves. Furthermore, cooling of the crystallized glass after heat treatment may be performed at a specific temperature gradient, or at two or more temperature gradient levels. To obtain sufficient thermal shock resistance, it is desirable to control the cooling rate to sufficiently relax the structure of the remaining glass phase. The average cooling rate from 800°C to 25°C is preferably 3000°C / min, 300°C / min or less, or 25°C / min or less in the inner part of the thickness farthest from the surface of the crystallized glass. Furthermore, when long-term dimensional stability is desired, it is further preferably 2.5°C / min or less, 0.1°C / min or less, 0.005°C / min or less, and particularly preferably 0.0001°C / min or less. Except when physical strengthening treatment is performed using air cooling, water cooling, etc., it is desirable that the cooling rate at the surface of the crystallized glass and the cooling rate at the inner part of the thickness farthest from the surface of the crystallized glass are similar. The value obtained by dividing the cooling rate at the inner part of the thickness farthest from the surface of the crystallized glass by the cooling rate at the surface of the crystallized glass is preferably 0.0001 to 1, 0.001 to 1, 0.01 to 1, 0.1 to 1, 0.5 to 1, 0.8 to 1, 0.9 to 1, and particularly 1. When the value is close to 1, residual strain is less likely to occur at all positions of the crystallized glass sample, making it easier to achieve long-term dimensional stability. The surface cooling rate can be estimated using a contact thermometer or a radiation thermometer, and the internal temperature can be estimated by placing the crystallized glass at a high temperature in a cooling medium, measuring the heat quantity and rate of heat change of the cooling medium, and using the numerical data, the specific heat, thermal conductivity, etc. of the crystallized glass and the cooling medium.

[0107] The present invention will be described below based on examples, but the present invention is not limited to the following examples. Tables 1 to 38 show examples of the present invention (samples No. 1 to 95).

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146] First, raw materials were mixed in the form of oxides, hydroxides, carbonates, nitrates, etc. to obtain a raw material batch so as to obtain glass having the composition shown in each table. The obtained raw material batch was melted at 1500-1700°C, formed into an ingot shape with a thickness of about 15 mm, heat-treated in an annealing furnace at 700°C for 60 minutes, and then cooled to room temperature at a rate of 100°C / h to obtain a glass sample (crystallizable glass). The compositions shown in the tables are analytical values ​​of the glasses actually produced. Melting was performed using an electric melting method, which is widely used in the development of glass materials.

[0147] The Pt and Rh contents of the samples were analyzed using an ICP-MS (inductively coupled plasma mass spectrometry) device (Agilent 8800 manufactured by AGILEINT TECHNOLOGY). First, the prepared glass sample was crushed and wetted with pure water, and then perchloric acid, nitric acid, sulfuric acid, hydrofluoric acid, etc. were added to melt the sample. Then, the Pt and Rh contents of the sample were measured by ICP-MS. The Pt and Rh contents of each measurement sample were determined based on a calibration curve prepared using a previously prepared Pt and Rh solution of known concentrations. The measurement mode was Pt:He gas / HMI (low mode) and Rh:HEHe gas / HMI (medium mode), and the mass numbers were Pt: 198 and Rh: 103. Note that the Li of the prepared sample ２ The O content was analyzed using an atomic absorption spectrometer (ContrAA600 manufactured by Analytik Jena). The method of melting the glass sample and the use of a calibration curve were basically the same as in the analysis of Pt and Rh. In addition, the other components, Pt, Rh, Li, etc. ２As with O, measurements were made by ICP-MS or atomic absorption spectrometry, or a glass sample with a known concentration previously determined using an ICP-MS or atomic absorption spectrometry analyzer was used as a calibration curve sample, and a calibration curve was then created using an XRF (X-ray fluorescence) analyzer (ZSX Primus IV manufactured by RIGAKU), and the actual content of each component was determined from the XRF analysis value of the measurement sample based on the calibration curve. During the XRF analysis, the tube voltage, tube current, exposure time, etc. were adjusted as needed depending on the components being analyzed.

[0148] Nucleation was performed on the crystallizable glasses shown in each table at 750 to 800°C for 0.75 to 10 hours, followed by crystal growth at 850 to 1000°C for 0.25 to 3 hours, and then heat treatment was performed at 1050 to 1200°C for 0.1 to 1 hour to promote crystal transition to β-spodumene solid solution, thereby obtaining LAS-based crystallized glasses containing β-spodumene solid solution crystals as the main crystals. The obtained LAS-based crystallized glasses were measured and evaluated for precipitated crystals (main crystals), density, thermal expansion coefficient, total light transmittance, diffuse transmittance, dielectric constant, tanδ, and dielectric loss. Furthermore, the β-OH, density, and thermal expansion coefficient of the crystallizable glasses before crystallization were measured and evaluated in the same manner as for the crystallized glasses, and the glass transition temperature (Tg), sag point (Tf), and temperature at high temperature viscosity (10 ４ dPa·s, 10 ３．５ dPa·s, 10 ３ dPa·s, 10 ２．５ dPa·s), liquidus viscosity (log η, η represents the viscosity (dPa·s) of glass at the liquidus temperature), liquidus temperature (T Ｌ ), and the initial phase was also measured and evaluated.

[0149] The β-OH was determined by measuring the transmittance of the glass before crystallization using an FT-IR Frontier (manufactured by Perkin Elmer) and using the following formula: The scan speed was 100 μm / min and the sampling pitch was 1 cm. －１ The number of scans was 5 per measurement. β-OH = (1 / X) log １０ (T １ / T ２ ) X: Glass thickness (mm) T １ :Reference wavelength 3846cm -１ Transmittance (%) at T２ : Hydroxyl group absorption wavelength 3600 cm -1 Minimum transmittance (%) in the vicinity

[0150] The precipitated crystals (main crystals) were evaluated using an X-ray diffractometer (Aeris, a tabletop X-ray diffractometer manufactured by Malvern Panalytical). The measurement range was 5 to 60°, the measurement step was 0.01°, and the scan rate was 1.5° / min, and the main crystals were evaluated using analysis software. The precipitated crystals (main crystals) identified as the main crystals are shown in the table. "β-spo." in the table means β-spodumene solid solution.

[0151] The density was evaluated by the Archimedes method.

[0152] The thermal expansion coefficient was evaluated by measuring the average linear thermal expansion coefficient of a glass sample processed to 20 mm x 3.8 mmφ in the temperature ranges of 30 to 380° C. and 30 to 750° C. A Dilatometer manufactured by NETZSCH was used for the measurement.

[0153] The appearance of the obtained crystallized glass was evaluated by visually inspecting the color of the crystallized glass, which was 10 mm square or larger and 4 mm thick, under a neutral white fluorescent lamp.

[0154] Total light transmittance was evaluated using a spectrophotometer to measure a 4 mm thick, double-sided optically polished crystallized glass plate (30 mm square). A JASCO V-670 spectrophotometer was used for the measurements. The V-670 was equipped with an integrating sphere unit, the ISN-723. The transmittance measured with the attached barium plate corresponds to the total diffuse transmittance. The measurement wavelength range was 380-780 nm, the scan speed was 200 nm / min, the sampling pitch was 1 nm, and the bandwidth was 5 nm. Measurements were also performed under similar conditions for wavelength ranges other than those mentioned above (200-2500 nm) as needed. However, measurements were performed with a bandwidth of 20 nm in the near-infrared region. Prior to measurement, baseline correction (100% alignment) and dark measurement (0% alignment) were performed. Dark measurements were performed with the attached barium sulfate plate removed from the ISN-723. The diffuse reflectance of the crystallized glass was measured using the same model as above, but by replacing the barium sulfate plate attached to the ISN-723 with a measurement sample, including specular reflection. The chromaticity at each transmittance was calculated using a D65 light source and a 2-degree field of view. The calculation method was in accordance with JIS Z 8781-4.

[0155] The dielectric constant and dielectric loss tangent at a frequency of 2.45 GHz and 25°C were measured from the change in resonance frequency and load using a cavity resonator (manufactured by AET) and a network analyzer (ZVL-3 manufactured by Rohde & Schwarz). The dielectric loss was calculated by multiplying the dielectric constant and dielectric loss tangent.

[0156] The thermal expansion curve of the glass sample was measured in the temperature range of 30 to 750° C. using a Dilatometer manufactured by NETZSCH, and the glass transition point and yield point were evaluated by calculating the inflection point.

[0157] The temperature at high-temperature viscosity was evaluated using the platinum ball pulling method. For the evaluation, a block glass sample was crushed to an appropriate size and placed in an alumina crucible, taking care to minimize the inclusion of air bubbles. The alumina crucible was then heated to turn the sample into a molten liquid. The viscosity of the glass at multiple temperatures was measured, and the constants of the Vogel-Fulcher equation were calculated to create a viscosity curve, from which the temperature at each viscosity was calculated.

[0158] The liquidus temperature was evaluated by the following method. First, a platinum boat of approximately 120 × 20 × 10 mm was filled with glass powder having a particle size of 300 to 500 micrometers, which was then placed in an electric furnace and melted at 1600 °C for 30 minutes. The platinum boat was then placed in an electric furnace with a linear temperature gradient for 20 hours to precipitate devitrified matter. After air-cooling the measurement sample to room temperature, the devitrified matter precipitated at the interface between the platinum boat and the glass was observed, and the temperature at the devitrified matter precipitation point was calculated from the temperature gradient graph of the electric furnace to obtain the liquidus temperature. The obtained liquidus temperature was then interpolated into the high-temperature viscosity curve of the glass, and the viscosity corresponding to the liquidus temperature was obtained as the liquidus viscosity.

[0159] The primary phases generated in the crystallized glass of the examples shown in each table were analyzed using X-ray diffraction, composition analysis, etc. (Hitachi scanning electron microscope, Hitachi S3400N Type PE2, Horiba EMAX ENERGY EX250X).

[0160] As is clear from Tables 1 to 38, the LAS crystallized glasses of Examples 1 to 95 were white, had low thermal expansion coefficients, and were excellent in dielectric loss characteristics.

[0161] FIG. 1 shows the L of the total light transmittance of 4 mm thick samples of the crystallized glass of each example of the present invention. ＊ This is a scatter diagram in which the L value is plotted against the value of the parameter a. As the value of the parameter a becomes smaller, the L ＊ It can be seen that the larger the value, the more transparent the film becomes.

[0162] 2 is a scatter diagram in which the total light transmittance at 1500 nm of 4 mm thick samples of the crystallized glass of each example of the present invention is plotted against the value of parameter b. It can be seen that the smaller the value of parameter b, the higher the total light transmittance at 1500 nm.

[0163] 3 is a scatter diagram in which the thermal expansion coefficients of the crystallized glasses of the examples of the present invention at 30 to 750° C. are plotted against the value of parameter c. This shows that the thermal expansion coefficients of the crystallized glasses tend to decrease as the value of parameter c decreases.

[0164] 4 is a scatter diagram in which the dielectric loss values ​​of the crystallized glass of each example of the present invention at a frequency of 2.45 GHz are plotted against the value of parameter d. From this, it can be seen that the dielectric loss of the crystallized glass at a frequency of 2.45 GHz tends to decrease as the value of parameter d decreases.

Claims

1. SiO2 (by mass%) ２ 55-75%, Al ２ O ３ 10-35%, Li ２ O 0.1-3.59%, BaO 0-10%, MgO 0-10%, TiO ２ 0.2-5%, ZrO ２ 0-5%, P ２ O ５ An LAS-based crystallized glass containing 0 to 5% of Li, and satisfying the following parameters a to d: a: 0 to 20%, b: 80% or less, c: 40% or less, and d: 65% or less, wherein β-spodumene solid solution is precipitated as the main crystal. ２ O+MgO+CaO+ZnO+TiO ２ )-(Na ２ O+K ２ O) b: Al ２ O ３ +BaO+4(SrO+ZnO)+8(CaO+Li ２ O) c: Al ２ O ３ -(Li ２ O+MgO)+2(CaO+SrO+P ２ O ５ )-2(TiO ２ + ZrO ２ ) + 3 (Na ２ O+K ２ O)-6SnO ２ d: Al ２ O ３ +ZnO+P ２ O ５ +2(MgO+CaO+BaO+ZrO ２ ) + 4TiO ２ +10Na ２ O 2. The LAS-based crystallized glass according to claim 1, characterized in that, in mass %, the parameters a to d satisfy: a: 3 to 10%, b: 30 to 70%, c: 25% or less, and d: 45% or less.

3. Al, by mass% ２ O ３ 15-30%, Li ２ O 2-3.49%, MgO 0-0.8%, CaO 0-1.6%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３ 30-2000ppm, V ２ O ５ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 0 to 1000 ppm of Zn.

4. Al, by mass% ２ O ３ 15-30%, Li ２ O 2.0-3.49%, BaO 2.7-10%, MgO+CaO 0-1.9%, ZrO ２ 1.4-5% Fe ２ O ３ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 30 to 10,000 ppm of Zn.

5. Al, by mass% ２ O ３ 15-30%, Li ２ O 2.0-3.5%, Na ２ O+K ２ O > 0~0.9%, BaO 2.6~10%, MgO+CaO 0~4%, TiO ２ 0.2-2.5%, ZrO ２ 0-2.9%, P ２ O ５ 0-2% Fe ２ O ３ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 30 to 10,000 ppm of Zn.

6. SiO2 (by mass%) ２ 55-68%, Al ２ O ３ 20-30%, Li ２ O 2.0-3.49%, Na ２ O+K ２ O 0-0.5%, BaO 0-2.7%, MgO+CaO 0-2.5%, TiO ２ 0.2-3.9%, ZrO ２ 1.4-2.9%, P ２ O ５ 0-2.5% Fe ２ O ３ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 30 to less than 900 ppm of ZnO, and the parameter a satisfies 3 to 8.

5.

7. Pr by mass% ６ O １１ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 0.1 to 2000 ppm of the following:

8. Sm by mass% ２ O ３ 3. The LAS-based crystallized glass according to claim 1, wherein the LAS-based crystallized glass contains 0.1 to 2000 ppm of the following:

9. By mass%, Li ２ 3. The LAS-based crystallized glass according to claim 1, comprising 0.1 to 3.47% of O and 2 to 10% of BaO.

10. By mass%, Na ２ O+K ２ 3. The LAS-based crystallized glass according to claim 1, further comprising more than 0% and less than 0.7% of O.

11. By mass%, P ２ O ５ 11. The LAS-based crystallized glass according to claim 10, containing 0.01 to 4% of Zn.

12. By mass%, Fe ２ O ３ 12. The LAS-based crystallized glass according to claim 11, containing 0 to less than 900 ppm.

13. LAS-based crystallized glass according to claim 12, characterized in that it contains, by mass %, 0 to 0.2% CaO.

14. The LAS-based crystallized glass according to claim 1 or 2, characterized in that the parameters a to d satisfy, in mass%, a: 5.2 to 8%, b: 45 to 55%, c: 5 to 15%, and d: 30 to 45%.

15. Substantially As ２ O ３ and Sb ２ O ３ 3. The LAS-based crystallized glass according to claim 1, which does not contain:

16. By mass ratio, Li ２ 3. The LAS-based crystallized glass according to claim 1, wherein O / BaO is 2.5 or less.

17. By mass ratio, (Na ２ O+K ２ 3. The LAS-based crystallized glass according to claim 1, wherein the ratio of (MgO+MgO) / BaO is 6 or less.

18. LAS-based crystallized glass according to claim 1 or 2, characterized in that it contains, by mass %, 0 to less than 1.1% of ZnO.

19. The thermal expansion coefficient between 30 and 750°C is -30 x 10 －７ / ℃~30×10 －７ 3. The LAS-based crystallized glass according to claim 1, wherein the temperature is 100°C.

20. L at total light transmittance of 4 mm thickness ＊ 3. The LAS-based crystallized glass according to claim 1, wherein the value is 50 or less.

21. L at diffuse reflectance of 4 mm thickness ＊ 3. The LAS-based crystallized glass according to claim 1, wherein the value is 60 or more.

22. The dielectric loss at a frequency of 2.45 GHz is 48 x 10 －３ 3. The LAS-based crystallized glass according to claim 1, wherein:

23. A method for producing LAS-type crystallized glass according to claim 1 or 2, comprising the steps of: melting glass raw materials to obtain molten glass; shaping the molten glass; and heat treating the glass obtained in the shaping of the molten glass to crystallize it.

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