Glass comprising crystalline phase

Abstract

In an X-ray diffraction spectrum obtained by an X-ray diffraction method, when the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 23.50 DEG to 24.00 DEG is set as I1 and the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 24.05 DEG to 24.55 DEG is set as I2, I1 is the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 23.50 DEG to 24.00 DEG, and I2 is the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 24.05 DEG to 24.55 DEG. And (I3 + I4) / (I1 + I2) is 1.60 or more, where I3 is the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 24.60-25.05 DEG, and I4 is the diffraction intensity of a diffraction peak present at a diffraction angle 2 [theta] = 25.20-26.60 DEG.

Description

Technical Field

[0001] The present invention relates to a glass containing a crystalline phase. Background Art

[0002] Sometimes, a glass containing a crystalline phase is used as a cover glass for a smartphone, a glass component of a housing, etc. Although the glass containing a crystalline phase can improve strength, on the other hand, there is a technical problem that it is difficult to ensure transparency. Patent Documents 1 to 4 disclose a glass containing a crystalline phase having specific components and physical properties.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-095333

[0006] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2001-048584

[0007] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2020-019659

[0008] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2008-254984 Summary of the Invention

[0009] An object of the present invention is to provide a glass having high transparency and containing a crystalline phase.

[0010] When the present inventors et al. conducted in-depth research by paying attention to the shape of the X-ray diffraction spectrogram measured for the glass containing a crystalline phase, it was found that when the intensities of a plurality of diffraction peaks appearing in a specific range on the X-ray diffraction spectrogram satisfy a specific relationship, the glass exhibits high transparency, and the present invention was completed.

[0011] The present invention provides the following products.

[0012] (Configuration 1)

[0013] A glass containing a crystalline phase, in the X-ray diffraction spectrogram obtained by X-ray diffraction method:

[0014] When the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ = 23.50° to 24.00° is set as I1, the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ = 24.05° to 24.55° is set as I2, the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ = 24.60° to 25.05° is set as I3, and the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ = 25.20° to 26.60° is set as I4, (I3 + I4) / (I1 + I2) is 1.60 or more.

[0015] (Constitution 2)

[0016] The glass containing a crystalline phase as described in Constitution 1, wherein (I3 + I4) / (I1 + I2) is 4.50 or less.

[0017] (Constitution 3)

[0018] The glass containing a crystalline phase as described in Constitution 1 or Constitution 2, wherein I4 is greater than I3.

[0019] (Constitution 4)

[0020] The glass containing a crystalline phase as described in any one of Constitutions 1 to 3, wherein I1 is greater than I2.

[0021] (Constitution 5)

[0022] The glass containing a crystalline phase as described in any one of Constitutions 1 to 4, wherein I3 is greater than I1.

[0023] (Constitution 6)

[0024] The glass containing a crystalline phase as described in any one of Constitutions 1 to 5, wherein I3 is greater than I2.

[0025] (Constitution 7)

[0026] The glass containing a crystalline phase as described in any one of Constitutions 1 to 6, wherein I4 is the largest among I1 to I4.

[0027] (Constitution 8)

[0028] The glass containing a crystalline phase as described in any one of Constitutions 1 to 7, wherein at the position of diffraction angle 2θ = 26.60° to 27.10° in the X-ray diffraction spectrogram, there is no diffraction peak.

[0029] (Constitution 9)

[0030] The glass containing a crystalline phase as described in any one of Constitutions 1 to 8, wherein the glass is a crystallized glass.

[0031] (Constitution 10)

[0032] The glass containing a crystalline phase as described in any one of Constitutions 1 to 9, wherein the components of the original glass are in terms of mass % in terms of oxide conversion:

[0033] The content of the SiO2 component is 65.0% to 85.0%;

[0034] The content of the Al2O3 component is 3.0% to 15.0%;

[0035] The content of the P2O5 component is greater than 0% to 5.0%;

[0036] The content of the Li2O component is greater than 5.0% to 15.0%;

[0037] The content of the ZrO2 component is 0% to 10.0%;

[0038] The content of the MgO component is 0% to 5.0%.

[0039] According to the present invention, it is possible to provide a glass containing a crystalline phase with high transparency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram showing the relationship between diffraction peaks and peak intensities in an X-ray diffraction spectrogram.

[0041] Figure 2 is the X-ray diffraction spectrogram obtained in Example 1.

[0042] Figure 3 is the X-ray diffraction spectrogram obtained in Example 9.

[0043] Figure 4 is the X-ray diffraction spectrogram obtained in Comparative Example 1.

[0044] Figure 5 is the X-ray diffraction spectrogram obtained in Comparative Example 2.

[0045] Figure 6 is the X-ray diffraction spectrogram obtained in Comparative Example 3.

[0046] Figure 7 is the X-ray diffraction spectrogram obtained in Comparative Example 4.

[0047] Figure 8 is the X-ray diffraction spectrogram obtained in Comparative Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0048] Hereinafter, embodiments and examples of the glass containing a crystalline phase of the present invention will be described in detail. However, the present invention is not limited to the following embodiments and examples, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0049] [Glass Containing a Crystalline Phase]

[0050] The X-ray diffraction spectrogram obtained by X-ray diffraction of a glass containing a crystalline phase according to one embodiment of the present invention satisfies the following conditions. That is:

[0051] When the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ is 23.50° to 24.00° (hereinafter, also referred to as "range 1") is set as I1, the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ is 24.05° to 24.55° (hereinafter, also referred to as "range 2") is set as I2, the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ is 24.60° to 25.05° (hereinafter, also referred to as "range 3") is set as I3, and the diffraction intensity of the diffraction peak existing at the position where the diffraction angle 2θ is 25.20° to 26.60° (hereinafter, also referred to as "range 4") is set as I4, (I3 + I4) / (I1 + I2) is 1.60 or more.

[0052] Hereinafter, the above relational expression "(I3 + I4) / (I1 + I2)" is sometimes referred to as "formula (1)".

[0053] Since the above glass containing a crystalline phase satisfies specific conditions (formula (1)) on the X-ray diffraction spectrogram, it exhibits high light transmittance and excellent transparency. Therefore, it can be used as components of cover glasses and casings for smartphones; components of portable electronic devices such as tablet PCs (personal computers) and wearable terminals; protective protectors used in transportation bodies such as automobiles and airplanes; components such as substrates for head-up displays, and the high transparency of the above glass can enhance the utilization value of the above various devices.

[0054] Hereinafter, each component of the glass containing a crystalline phase of the present invention will be described.

[0055] <Formula (1)>

[0056] The inventors of the present invention have particularly focused on the intensities of the diffraction peaks appearing in ranges 1 to 4 of the X-ray diffraction spectrogram, and have found that when the sum of the diffraction intensities of the diffraction peaks appearing at two places on the high-angle side (ranges 3 and 4) is greater than the sum of the diffraction intensities of the diffraction peaks appearing at two places on the low-angle side (ranges 1 and 2) by a certain degree or more, the glass containing a crystalline phase exhibits high transparency. Formula (1) is a formula representing this situation.

[0057] In addition, the glass containing a crystalline phase of the present invention may contain, for example, one or more crystalline phases selected from the group consisting of a crystalline phase derived from lithium disilicate (also referred to as lithium metasilicate or Lithium disilicate), a crystalline phase derived from spodumene, a crystalline phase derived from β-quartz solid solution, and a crystalline phase derived from petalite as the crystalline phase.

[0058] In one embodiment, the glass containing a crystalline phase of the present invention comprises a crystalline phase derived from lithium disilicate, a crystalline phase derived from spodumene, a crystalline phase derived from β - quartz solid solution, and a crystalline phase derived from lithium aluminosilicate.

[0059] In one embodiment, the glass containing a crystalline phase of the present invention comprises a crystalline phase derived from lithium disilicate, a crystalline phase derived from lithium aluminosilicate, and a crystalline phase derived from β - quartz solid solution.

[0060] In one embodiment, the glass containing a crystalline phase of the present invention comprises a crystalline phase derived from lithium disilicate, and a crystalline phase derived from lithium aluminosilicate.

[0061] (Formula (1))

[0062] There is no particular limitation as long as (I3 + I4) / (I1 + I2) is 1.60 or more.

[0063] (I3 + I4) / (I1 + I2) can also be, for example, 1.70 or more, 1.80 or more, or 1.90 or more.

[0064] There is no particular limitation on the upper limit value of (I3 + I4) / (I1 + I2), for example, it is 4.50 or less.

[0065] There is no particular limitation on the magnitude relationship among I1 to I4. In one embodiment, I4 is the largest among I1 to I4.

[0066] There is no particular limitation on the magnitude relationship between I1 and I2. In one embodiment, I1 is greater than I2 (I1 > I2). For example, I1 is greater than twice I2 (I1 > 2I2).

[0067] There is no particular limitation on the magnitude relationship between I3 and I4. In one embodiment, I4 is greater than I3 (I4 > I3). For example, I4 is greater than twice I3 (I4 > 2I3).

[0068] There is no particular limitation on the magnitude relationship between I1 and I3. In one embodiment, I3 is greater than I1 (I3 > I1).

[0069] There is no particular limitation on the magnitude relationship between I2 and I3. In one embodiment, I3 is greater than I2 (I3 > I2).

[0070] Furthermore, diffraction peaks do not necessarily need to exist in each of the four ranges from Range 1 to Range 4. For example, even when diffraction peaks do not exist in any one of Range 1 and Range 2, as long as Formula (1) is satisfied, it still belongs to the glass containing a crystalline phase of the present invention.

[0071] (X - ray diffraction spectrogram)

[0072] "Diffraction peaks present at positions where the diffraction angle 2θ is from AA° to BB°" refers to the convex portions that are the maxima in the X-ray diffraction spectrogram within the range of the diffraction angle 2θ from AA° to BB°. When two or more diffraction peaks are present in this range, it refers to the diffraction peak with the maximum diffraction intensity among them. Furthermore, although it goes without saying from the above, when there is no maximum value within the range of the diffraction angle 2θ from AA° to BB°, no diffraction peak is present in this range. Moreover, a "diffraction peak" refers to a diffraction peak having a magnitude that can be clearly distinguished from noise.

[0073] In Figure 1 represents a schematic diagram showing the relationship between the diffraction peaks and peak intensities in the X-ray diffraction spectrogram. The X-ray diffraction spectrogram is obtained by the method described in the examples.

[0074] (Other diffraction peaks, etc.)

[0075] The glass containing a crystalline phase of the present invention may or may not have a diffraction peak at a position where the diffraction angle 2θ in the X-ray diffraction spectrogram is from 26.60° to 27.10° (hereinafter, also referred to as "Range 5".). (The diffraction intensity of the diffraction peak in Range 5 is also referred to as "I5".)

[0076] The glass containing a crystalline phase of one embodiment of the present invention does not have a diffraction peak in Range 5. Thus, an effect of obtaining higher transparency can be expected.

[0077] "Not having a diffraction peak" means that there is no diffraction peak having a magnitude that can be clearly distinguished from noise.

[0078] Figure 1 , Figure 2 (Example 1), Figure 3 (Example 9), and Figure 4 (Comparative Example 1) shown in the X-ray diffraction spectrograms are examples that do not have a diffraction peak in Range 5, Figures 5 to 8 (Comparative Examples 2 to 5) shown in the X-ray diffraction spectrograms are examples that have a diffraction peak in Range 5.

[0079] Furthermore, as the crystalline phase showing a diffraction peak in Range 5, examples include: a crystalline phase derived from lithium metasilicate.

[0080] <Glass containing a crystalline phase>

[0081] The glass containing a crystalline phase of the present invention is a glass material having a crystalline phase and a glass phase and is different from an amorphous material.

[0082] The glass containing a crystalline phase of the present invention is, for example, a crystallized glass.

[0083] The glass containing a crystalline phase of the present invention can be manufactured by adjusting the raw material components and manufacturing conditions with reference to the manufacturing methods and examples described below.

[0084] Furthermore, the glass containing a crystalline phase of the present invention can form a compressive stress layer on the surface by various strengthening methods (such as chemical strengthening method, thermal strengthening method, and ion implantation method, etc.).

[0085] In one mode, the glass containing a crystalline phase of the present invention (for example, crystallized glass) has a light transmittance (%) of 70% or more, 75% or more, or 80% or more at 550 nm in a sample with a thickness of 10 mm. The light transmittance (%) at 550 nm is measured by the method described in the examples.

[0086] In one embodiment, the glass containing a crystalline phase of the present invention (for example, crystallized glass) has an average light transmittance (%) of 70% or more, 75% or more, or 80% or more from 400 nm to 800 nm in a sample with a thickness of 10 mm. The average light transmittance (%) from 400 nm to 800 nm is measured by the method described in the examples.

[0087] In one embodiment, the glass containing a crystalline phase of the present invention (for example, crystallized glass) has a linear coefficient of thermal expansion from 100 °C to 300 °C of 8 × 10 -6 K -1 Hereinafter, 7 × 10 -6 K -1 Hereinafter, or 5 × 10 -6 K -1 Hereinafter, for example, 2 × 10 -6 K -1 Hereinafter, or 3 × 10 -6 K -1 Hereinafter. The linear coefficient of thermal expansion is measured by the method described in the examples.

[0088] (Crystallized glass)

[0089] Crystallized glass is also called glass-ceramics, which refers to a material in which crystals precipitate inside the glass by heat-treating the glass. Crystallized glass is a material having a crystalline phase and a glass phase and is different from amorphous solids. Generally, the crystalline phase of crystallized glass is discriminated by the angles of the peaks appearing in the X-ray diffraction pattern obtained by X-ray diffraction analysis.

[0090] Crystallized glass can be produced by the following method. That is, the raw materials are uniformly mixed so that each component is within a predetermined content range, and the raw glass is manufactured by melting and molding. Subsequently, the raw glass is crystallized to produce crystallized glass.

[0091] (Raw glass)

[0092] In one embodiment, the components of the original glass are in mass % on an oxide conversion basis:

[0093] The content of the SiO2 component is 65.0% to 85.0%;

[0094] The content of the Al2O3 component is 3.0% to 15.0%;

[0095] The content of the P2O5 component is more than 0% to 5.0%;

[0096] The content of the Li2O component is more than 5.0% to 15.0%;

[0097] The content of the ZrO2 component is 0% to 10.0%;

[0098] The content of the MgO component is 0% to 5.0%.

[0099] Furthermore, in one embodiment:

[0100] [Content of Al2O3 component / (Content of K2O component + Content of MgO component)] is more than 0 to 20.0;

[0101] [Content of Li2O component / Content of MgO component] is 6.0 or more.

[0102] In this specification, unless otherwise specifically negated, the content of each component is all expressed in mass % on an oxide conversion basis. Here, "oxide conversion" means that when it is assumed that all the components of the crystallized glass are decomposed into oxides, and the total mass of the oxides is set to 100 mass %, the amount of the oxides of each component contained in the crystallized glass is marked as a value in mass %. In this specification, A% to B% means A% or more to B% or less.

[0103] The original glass can be easily deformed into a curved shape by hot working, and in order to obtain a high light transmittance in the visible region for the crystallized glass component, in addition to having the above components, it can also have the following constitution.

[0104] The SiO2 component is the framework component of the glass containing the crystalline phase, and is a component for improving stability and causing the desired crystalline phase to precipitate. If the content of the SiO2 component is set to 85.0% or less, an excessive increase in viscosity and deterioration of meltability can be suppressed. Furthermore, if it is set to 65.0% or more, the stability of the glass containing the crystalline phase can be improved.

[0105] Therefore, it is preferable to set the upper limit to 85.0% or less, more preferably to 83.0% or less, and still more preferably to 80.0% or less. Furthermore, it is preferable to set the lower limit to 65.0% or more, and for example, it may also be set to 68.0% or more, or greater than 70.0%.

[0106] The Al2O3 component is a skeletal component constituting the inorganic part of the article and is a component for improving stability. If the content of the Al2O3 component is 15.0% or less, the deterioration of devitrification can be suppressed. Furthermore, if it is 3.0% or more, the deterioration of stability can be suppressed.

[0107] Therefore, it is preferable to set the upper limit to 15.0% or less, more preferably to 13.0% or less, and for example, it may be set to less than 12.0%. Furthermore, it is preferable that the lower limit can be set to 3.0% or more, more preferably to 4.0% or more, still more preferably to 5.0% or more, yet more preferably to greater than 7.0%, and further preferably to greater than 8.0%.

[0108] The P2O5 component is an essential component for promoting the crystallization of the glass containing a crystalline phase. If the content of the P2O5 component is 5.0% or less, the phase separation of the glass can be suppressed.

[0109] Therefore, it is preferable to set the upper limit to 5.0% or less, more preferably to 4.5% or less, and still more preferably to 4.0% or less. Furthermore, it is preferable to set the lower limit to greater than 0%, more preferably to 0.5% or more, and still more preferably to 1.0% or more.

[0110] The content of the P2O5 component may also be set to 3.0% or less, 2.7% or less, or 2.5% or less. Furthermore, the content of the P2O5 component may also be set to 1.5% or more, or 2.0% or more.

[0111] The Li2O component is a component that improves the meltability of the raw glass and enhances the manufacturability. If the content of the Li2O component is 15.0% or less, the deterioration of devitrification can be suppressed. Furthermore, if it is set to greater than 5.0%, the deterioration of viscosity and meltability can be suppressed, and the manufacturability can be improved.

[0112] Therefore, it is preferable to set the lower limit to greater than 5.0%, more preferably to 6.0% or more, and still more preferably to 7.0% or more. Furthermore, it is preferable to set the upper limit to 15.0% or less, more preferably to 13.0% or less, and for example, it may also be set to 12.0% or less.

[0113] Even if the ZrO2 component is 0%, the glass containing a crystalline phase of the present invention can be produced. However, when the content is greater than 0%, it is a component that becomes a nucleating agent for crystallization. If the content of the ZrO2 component is 10.0% or less, the deterioration of meltability can be suppressed.

[0114] Therefore, it is preferable to set the upper limit to 10.0% or less, more preferably 8.0% or less, still more preferably 5.0% or less, and further preferably 4.0% or less. Furthermore, it may also be set to 3.0% or less, 2.5% or less, or less than 2.5%. Furthermore, it is preferable that the lower limit can be set to 0% or more, more preferably 0.3% or more, and still more preferably 0.5% or more. Furthermore, it may also be set to 0.8% or more, 1.0% or more, or more than 1.5%.

[0115] Even if the MgO component is 0%, the glass containing a crystalline phase of the present invention can be produced, but when its content is greater than 0%, it is a component that improves the low-temperature meltability. If the content of the MgO component is 5.0% or less, it becomes easier to strengthen during chemical strengthening.

[0116] Therefore, it is preferable to set the upper limit to 5.0% or less, more preferably 3.0% or less, and still more preferably less than 2.0%. Furthermore, it is preferable that the lower limit can be set to 0% or more, more preferably 0.1% or more, and still more preferably 0.2% or more.

[0117] Even if the ZnO component is 0%, the glass containing a crystalline phase of the present invention can be produced, but when its content is greater than 0%, it is a component that improves the low-temperature meltability. If the content of the ZnO component is 5.0% or less, it becomes easier to strengthen during chemical strengthening.

[0118] Therefore, it is preferable to set the upper limit to 5.0% or less, more preferably 3.0% or less, and still more preferably less than 2.0%. Furthermore, it is preferable that the lower limit can be set to 0% or more, more preferably greater than 0%, still more preferably 0.1% or more, and further preferably 0.2% or more.

[0119] Even if the CaO component is 0%, the glass containing a crystalline phase of the present invention can be produced, but when its content is greater than 0%, it is a component that improves the low-temperature meltability. If the content of the CaO component is 5.0% or less, it becomes easier to strengthen during chemical strengthening.

[0120] Therefore, it is preferable to set the upper limit to 5.0% or less, more preferably 3.0% or less, and still more preferably less than 1.0%.

[0121] Even if the SrO component and the BaO component are 0% respectively, the glass of the present invention can be produced, but when the content of these components is greater than 0%, they are components that improve the low-temperature meltability. If the content of the SrO component and the BaO component is 5.0% or less respectively, it becomes easier to strengthen during chemical strengthening.

[0122] Therefore, the upper limit of the SrO component and the BaO component is preferably set to 5.0% or less, more preferably set to 3.0% or less, and still more preferably set to 1.0% or less.

[0123] Even if the Gd2O3 component is 0%, the glass of the present invention can be produced. However, when its content is greater than 0%, it is a component that increases the refractive index and can reduce the partial dispersion ratio. On the other hand, if a large amount of the Gd2O3 component is contained, there is a risk of devitrification due to a decrease in the liquidus temperature. By setting the Gd2O3 component to 10.0% or less, devitrification can be reduced and coloring can be reduced.

[0124] Therefore, the upper limit of the content of the Gd2O3 component is preferably set to 10.0% or less, more preferably set to 8.0% or less, still more preferably set to 5.0% or less, and most preferably set to 3.0% or less.

[0125] By setting the total content of the CaO component and the MgO component [content of the CaO component + content of the MgO component] to 5.0% or less, it is possible to avoid difficulty in chemical strengthening. Even if it is 0%, the glass containing a crystalline phase of the present invention can be produced. However, when the content is greater than 0%, deterioration of meltability can be suppressed.

[0126] Therefore, the upper limit of [content of the CaO component + content of the MgO component] is preferably set to 5.0% or less, more preferably set to 3.0% or less, still more preferably set to less than 3.0%, and further preferably set to 1.0% or less.

[0127] Furthermore, the lower limit of [content of the CaO component + content of the MgO component] is preferably 0% or more, more preferably set to greater than 0%, still more preferably set to 0.1% or more, and further preferably set to 0.2% or more.

[0128] The K2O component and the Na2O component are components that improve the meltability of the raw glass and improve manufacturability. If the content of the K2O component and the Na2O component is 5.0% or less respectively, deterioration of devitrification properties can be suppressed. Furthermore, even if the K2O component and the Na2O component are 0% respectively, the glass containing a crystalline phase of the present invention can be produced. However, when the content of these components is greater than 0%, deterioration of viscosity and meltability can be suppressed, and manufacturability can be improved.

[0129] Therefore, the lower limit of the K2O component and the Na2O component is preferably set to 0% or more, more preferably set to 0.2% or more, and still more preferably set to 0.3% or more. Furthermore, the upper limit of the K2O component and the Na2O component is preferably set to 5.0% or less, more preferably set to 4.0% or less, still more preferably set to less than 3.0%, and further preferably set to less than 2.0%.

[0130] The Sb2O3 component functions as a clarifying agent when manufacturing the original glass. If the content of the Sb2O3 component is excessive, there is a risk that the transmittance in the short wavelength region of the visible light region deteriorates. Therefore, it is preferably set the upper limit to 2.0% or less, more preferably 1.0% or less, still more preferably 0.6% or less, and further preferably 0.5% or less.

[0131] Furthermore, it is preferably set the lower limit to 0% or more, more preferably greater than 0%, still more preferably 0.001% or more, yet more preferably 0.01% or more, and further preferably 0.05% or more.

[0132] The B2O3 component has the effect of reducing the viscosity of the original glass. If the content of the B2O3 component is 10.0% or less, the deterioration of devitrification can be suppressed. Furthermore, even if the content of the B2O3 component is 0%, the glass containing a crystalline phase of the present invention can be produced, but when the content is greater than 0%, the deterioration of the viscosity of the original glass and the deterioration of the meltability can be suppressed.

[0133] Therefore, it is preferably set the upper limit to 10.0% or less, more preferably 8.0% or less, still more preferably 7.0% or less, yet more preferably 5.0% or less, and further preferably 4.0% or less, and still further preferably 3.0% or less.

[0134] Furthermore, it is preferably set the lower limit to 0% or more, more preferably greater than 0%, still more preferably 0.001% or more, yet more preferably 0.01% or more, and further preferably 0.05% or more, and still further preferably 0.10% or more, and even more preferably 0.30% or more.

[0135] Even if the total content of the K2O component and the Na2O component [content of the K2O component + content of the Na2O component] is 0%, the glass containing a crystalline phase of the present invention can be produced, but when the content is greater than 0%, the deterioration of the viscosity can be suppressed, and the increase in the melting temperature can be suppressed. Furthermore, by setting it to 5.0% or less, the deterioration of devitrification can be suppressed.

[0136] Therefore, for [content of the K2O component + content of the Na2O component], it is preferably set the lower limit to 0% or more, more preferably 0.1% or more, still more preferably 0.2% or more, and further preferably 0.3% or more. Furthermore, it is preferably set the upper limit to 5.0% or less, more preferably 4.0% or less, still more preferably less than 4.0%, further preferably less than 3.0%, and even more preferably less than 2.0%.

[0137] By setting the total content of the MgO component, CaO component, SrO component, BaO component, and ZnO component [MgO component + CaO component + SrO component + BaO component + ZnO component] to 15.0% or less, chemical strengthening can be made easier. Furthermore, even when [MgO component + CaO component + SrO component + BaO component + ZnO component] is 0%, the glass of the present invention containing a crystalline phase can be produced, but when the content is greater than 0%, deterioration of meltability can be suppressed.

[0138] Therefore, it is preferable to set the lower limit of [MgO component + CaO component + SrO component + BaO component + ZnO component] to 0% or more, more preferably to greater than 0%, still more preferably to 0.5% or more, and it can also be set to 1.0% or more. Furthermore, it is preferable to set the upper limit to 15.0% or less, more preferably to 10.0% or less, still more preferably to 5.0% or less, and further preferably to 3.5% or less.

[0139] By setting [the content of the Al2O3 component / the content of the K2O component] to 100.0 or less, deterioration of viscosity can be suppressed. Furthermore, by setting it to 0.6 or more, deterioration of devitrification resistance can be suppressed.

[0140] Therefore, it is preferable to set the upper limit of [the content of the Al2O3 component / the content of the K2O component] to 100.0 or less, more preferably to 80.0 or less, still more preferably to 60.0 or less, yet more preferably to 40.0 or less, further preferably to 20.0 or less, and even more preferably to 15.0 or less.

[0141] Furthermore, it is preferable to set the lower limit of [the content of the Al2O3 component / the content of the K2O component] to 0.6 or more, more preferably to 1.0 or more, still more preferably to 2.0 or more, yet more preferably to 3.0 or more, and further preferably to 5.7 or more. Furthermore, the content of the K2O component can also be set to 0.

[0142] If [the content of the Al2O3 component / (the content of the K2O component + the content of the MgO component)] is set to 20.0 or less, deterioration of viscosity can be suppressed. Furthermore, if it is set to greater than 0, deterioration of devitrification resistance can be suppressed.

[0143] Therefore, it is preferable to set the upper limit to 20.0 or less, more preferably to 18.0 or less, still more preferably to 16.0 or less, and further preferably to 15.0 or less.

[0144] Furthermore, it is preferable to set the lower limit of [the content of the Al2O3 component / (the content of the K2O component + the content of the MgO component)] to greater than 0, more preferably to 1.0 or more, still more preferably to 2.0 or more, and further preferably to 2.6 or more.

[0145] By setting [content of Al2O3 component / (content of ZnO component + content of MgO component)] to 20.0 or less, deterioration of fusibility can be suppressed, and by setting it to 3.0 or more, deterioration of devitrification property can be suppressed.

[0146] Therefore, it is preferable to set the upper limit of [content of Al2O3 component / (content of ZnO component + content of MgO component)] to 20.0 or less, more preferably to 18.0 or less, still more preferably to 17.0 or less, and also preferably to 16.0 or less. Furthermore, it is preferable to set the lower limit to 3.0 or more, more preferably to 4.0 or more, and also preferably to more than 5.0.

[0147] By setting [content of Li2O component / content of MgO component] to 150.0 or less, deterioration of devitrification property can be suppressed, and by setting it to 6.0 or more, chemical strengthening can be facilitated.

[0148] Therefore, the preferable upper limit of [content of Li2O component / content of MgO component] can be set to 150.0 or less, more preferably to 100.0 or less, still more preferably to 50.0 or less, and further preferably to 30.0 or less. Furthermore, it can also be set to 25.0 or less, or 23.0 or less. Moreover, MgO can also be set to 0.

[0149] On the other hand, the preferable lower limit of [content of Li2O component / content of MgO component] is 6.0 or more, and it can also be set to 7.0 or more, 8.0 or more, 9.0 or more, 9.5 or more, 10.0 or more, or 10.6 or more.

[0150] By setting [content of Li2O component / (content of MgO component + content of CaO component + content of SrO component + content of BaO component + content of Na2O component + content of K2O component)] to 50.0 or less, fusibility can be improved, and deterioration of devitrification property can be suppressed. Furthermore, by setting it to 1.0 or more, it is possible to avoid making chemical strengthening difficult to perform.

[0151] Therefore, the preferable upper limit of [content of Li2O component / (content of MgO component + content of CaO component + content of SrO component + content of BaO component + content of Na2O component + content of K2O component)] can be set to 50.0 or less, more preferably to 35.0 or less, still more preferably to 30.0 or less, yet more preferably to 20.0 or less, further preferably to 15.0 or less, still further preferably to 13.0 or less, and even more preferably to 10.0 or less.

[0152] Furthermore, [content of Li2O component / (content of MgO component + content of CaO component + content of SrO component + content of BaO component + content of Na2O component + content of K2O component)] can be set to 0.

[0153] On the other hand, the preferable lower limit of [content of Li2O component / (content of MgO component + content of CaO component + content of SrO component + content of BaO component + content of Na2O component + content of K2O component)] can be set to 1.0 or more, more preferably 2.0 or more, still more preferably 3.0 or more, and further preferably greater than 3.0.

[0154] By setting [content of MgO component / (content of Li2O component + content of MgO component)] to 0.6 or less, it is possible to avoid the difficulty of chemical strengthening and suppress the deterioration of devitrification property. Even if the lower limit is 0, the glass containing a crystalline phase of the present invention can be produced. However, by setting it to greater than 0, the devitrification property can be maintained and the low-temperature fusibility can be improved.

[0155] Therefore, the preferable upper limit of [content of MgO component / (content of Li2O component + content of MgO component)] is set to 0.6 or less, more preferably 0.3 or less, and still more preferably less than 0.15.

[0156] On the other hand, the preferable lower limit of [content of MgO component / (content of Li2O component + content of MgO component)] can be set to 0 or more, more preferably 0.01 or more, still more preferably 0.03 or more, and further preferably 0.04 or more.

[0157] The total content of Li2O component, Na2O component, and K2O component [content of Li2O component + content of Na2O component + content of K2O component] is an index for improving fusibility and the difficulty of producing the original glass. That is, by setting it to 17.0% or less, the deterioration of devitrification property can be suppressed, and by setting it to 3.0% or more, the deterioration of viscosity and the increase in melting temperature can be suppressed.

[0158] Therefore, the preferable upper limit of [content of Li2O component + content of Na2O component + content of K2O component] is set to 17.0% or less, more preferably 15.0% or less, and still more preferably 14.0% or less.

[0159] Furthermore, the preferable lower limit of [content of Li2O component + content of Na2O component + content of K2O component] can be set to 3.0% or more, more preferably 5.0% or more, and still more preferably 8.0% or more.

[0160] As long as the total content of the Li2O component and the P2O5 component [content of Li2O component + content of P2O5 component] is 18.0% or less, deterioration of devitrification resistance can be suppressed. Furthermore, [content of Li2O component + content of P2O5 component] is, for example, 8.0% or more.

[0161] Therefore, the preferred upper limit of [content of Li2O component + content of P2O5 component] is set to 18.0% or less, more preferably 17.0% or less, and can also be, for example, 15.0% or less, 14.0% or less, or 13.8% or less.

[0162] Furthermore, the preferred lower limit of [content of Li2O component + content of P2O5 component] can be set to 8.0% or more, more preferably 9.0% or more, still more preferably 10.0% or more, even more preferably 11.5% or more, and further preferably 12.01% or more.

[0163] As long as the total content of the Li2O component, the P2O5 component, and Al2O3 [content of Li2O component + content of P2O5 component + content of Al2O3 component] is 40.0% or less, deterioration of devitrification resistance can be suppressed. Furthermore, as long as [content of Li2O component + content of P2O5 component + content of Al2O3 component] is 21.5% or more, an effect of promoting precipitation of microcrystals can be expected.

[0164] Therefore, the preferred upper limit of [content of Li2O component + content of P2O5 component + content of Al2O3 component] is set to 40.0% or less, more preferably 35.0% or less, and can also be 27.5% or less, 25.0% or less, 24.5% or less, 24.0% or less, 23.8% or less, or 23.5% or less.

[0165] Furthermore, the preferred lower limit of [content of Li2O component + content of P2O5 component + content of Al2O3 component] can be set to 21.5% or more, more preferably 21.8% or more, still more preferably 22.0% or more, even more preferably 22.5% or more, and can also be 22.8% or more.

[0166] As long as [content of P2O5 component / content of MgO component] is 50.0 or less, deterioration of low-temperature fusibility can be suppressed. Furthermore, [content of P2O5 component / content of MgO component] is, for example, greater than 0.

[0167] Therefore, the preferred upper limit of [content of P2O5 component / content of MgO component] is set to 50.0 or less, more preferably 30.0 or less, still more preferably 10.0 or less, further preferably 7.0 or less, and may also be set to 5.0 or less, 4.1 or less, 4.0 or less, or 3.7 or less. Furthermore, the content of the MgO component may be 0.

[0168] Furthermore, the preferred lower limit of [content of P2O5 component / content of MgO component] may be set to greater than 0, more preferably 0.02 or more, still more preferably 0.1 or more, yet more preferably 0.15 or more, further preferably 1.0 or more, and may also be set to 1.5 or more, or 2.4 or more.

[0169] [content of SiO2 component / content of ZrO2 component] is, for example, 150.0 or less. By setting it to 10.0 or more, deterioration of devitrification resistance can be suppressed.

[0170] Therefore, the preferred upper limit of [content of SiO2 component / content of ZrO2 component] is 150.0 or less, and may also be set to 100.0 or less, 50.0 or less, 40.0 or less, 37.0 or less, 35.4 or less, 35.0 or less, 33.7 or less, or 32.7 or less.

[0171] Furthermore, the preferred lower limit of [content of SiO2 component / content of ZrO2 component] is 10.0 or more, and may also be set to 13.0 or more, 15.0 or more, 17.0 or more, 18.0 or more, 19.6 or more, 29.9 or more.

[0172] By setting [content of SiO2 component / content of Li2O component] to 17.0 or less, deterioration of low-temperature fusibility can be suppressed. Furthermore, [content of SiO2 component / content of Li2O component] is, for example, 4.0 or more.

[0173] Therefore, the preferred upper limit of [content of SiO2 component / content of Li2O component] is set to 17.0 or less, more preferably 15.0 or less, still more preferably 13.0 or less, yet more preferably 10.0 or less, further preferably 9.0 or less, and even more preferably 7.6 or less.

[0174] Furthermore, the preferred lower limit of [content of SiO2 component / content of Li2O component] may be set to 4.0 or more, more preferably 4.3 or more, still more preferably 5.0 or more.

[0175] [content of SiO2 component / content of P2O5 component] is, for example, 100.0 or less. By setting it to 13.0 or more, deterioration of devitrification resistance can be suppressed.

[0176] Therefore, the preferred upper limit of [content of SiO2 component / content of P2O5 component] is set to 100.0 or less, more preferably 80.0 or less, still more preferably 50.0 or less, yet more preferably 40.0 or less, and further preferably 39.0 or less.

[0177] Furthermore, the preferred lower limit of [content of SiO2 component / content of P2O5 component] can be set to 13.0 or more, more preferably 17.0 or more, and still more preferably 20.0 or more. Furthermore, it can also be set to 25.0 or more, 30.0 or more, or 33.0 or more.

[0178] [content of SiO2 component / (content of P2O5 component + content of ZrO2 component)] is, for example, 100.0 or less. By setting it to 4.3 or more, deterioration of devitrification resistance can be suppressed.

[0179] Therefore, the preferred upper limit of [content of SiO2 component / (content of P2O5 component + content of ZrO2 component)] is set to 100.0 or less, more preferably 80.0 or less, still more preferably 50.0 or less, yet more preferably 42.5 or less, and further preferably 35.0 or less. It can also be set to 30.0 or less, 25.0 or less, 20.0 or less, or 17.99 or less.

[0180] Furthermore, the preferred lower limit of [content of SiO2 component / (content of P2O5 component + content of ZrO2 component)] can be set to 4.3 or more, more preferably 10.0 or more. Furthermore, it can also be set to 13.0 or more, 15.0 or more, or 16.1 or more.

[0181] By setting [content of SiO2 component / (content of Na2O component + content of K2O component)] to 120.0 or less, deterioration of low-temperature fusibility can be suppressed. Furthermore, [content of SiO2 component / (content of Na2O component + content of K2O component)] is, for example, 23.0 or more.

[0182] Therefore, the preferred upper limit of [content of SiO2 component / (content of Na2O component + content of K2O component)] is set to 120.0 or less, more preferably 110.0 or less, still more preferably 100.0 or less (or less than 100.0), yet more preferably 90.0% or less, and further preferably 80.0% or less.

[0183] Furthermore, the preferred lower limit of [content of SiO2 component / (content of Na2O component + content of K2O component)] is set to 23.0 or more, more preferably 25.0 or more, still more preferably 30.0 or more, yet more preferably 35.0 or more, and may also be 54.0 or more.

[0184] [content of ZnO component / (content of Li2O component + content of P2O5 component + content of MgO component)] is, for example, 1.0 or less. Even if the lower limit is 0, the glass containing a crystalline phase of the present invention can be produced. However, by setting it to be greater than 0, devitrification resistance can be maintained and low-temperature fusibility can be improved.

[0185] Therefore, the preferred upper limit of [content of ZnO component / (content of Li2O component + content of P2O5 component + content of MgO component)] is set to 1.0 or less, more preferably 0.09 or less, still more preferably less than 0.06, and further preferably 0.05 or less.

[0186] Furthermore, the preferred lower limit of [content of ZnO component / (content of Li2O component + content of P2O5 component + content of MgO component)] can be set to 0 or more, more preferably greater than 0, still more preferably 0.01 or more, yet more preferably 0.02 or more, and further preferably 0.03 or more.

[0187] By setting [(content of SiO2 component + content of Al2O3 component + content of P2O5 component) / (content of Li2O component + content of Na2O component + content of K2O component + content of MgO component)] to 9.0 or less, deterioration of low-temperature fusibility can be suppressed. By setting it to 0.7 or more, crystallization precipitation can be promoted.

[0188] Therefore, the preferred upper limit of [(content of SiO2 component + content of Al2O3 component + content of P2O5 component) / (content of Li2O component + content of Na2O component + content of K2O component + content of MgO component)] is set to 9.0 or less, more preferably 8.0 or less, still more preferably 7.5 or less, and further preferably less than 7.25.

[0189] Furthermore, the preferred lower limit of [(content of SiO2 component + content of Al2O3 component + content of P2O5 component) / (content of Li2O component + content of Na2O component + content of K2O component + content of MgO component)] is 0.7 or more, more preferably 4.0 or more, still more preferably 5.0 or more, and may also be 6.0 or more.

[0190] Within the scope that does not impair the effects of the present invention, the glass containing a crystalline phase may also contain TiO2 component, Bi2O3 component, Cr2O3 component, CuO component, La2O3 component, MnO component, MoO3 component, PbO component, V2O5 component, WO3 component, Y2O3 component, or may not contain these components. By not containing these components, there is an effect of preventing deterioration of transmittance.

[0191] Furthermore, within the scope that does not impair the characteristics of the crystallized glass of the present invention, the crystallized glass may contain other components not mentioned above, or may not contain these components. For example, metal components such as Yb, Lu, Fe, Co, Ni, and Ag (including their metal oxides), etc.

[0192] Also, as a fining agent for the glass, in addition to the Sb2O3 component, it may also contain SnO2 component, CeO2 component, As2O3 component, and one or more selected from the group consisting of F, NOx, and SOx, or may not contain these components. However, the upper limit of the content of the fining agent is preferably set to 3.0% or less, more preferably 2.0% or less, still more preferably 1.0% or less, and most preferably 0.6% or less.

[0193] On the other hand, each component of Pb, Th, Tl, Os, Be, Cl, and Se has become a harmful chemical substance in recent years and tends to be used less, so it is preferably substantially free of these components. "Substantially free of" means containing them as inevitable impurities or being completely free of them. The total content of these components, for example, is 0.1% or less.

[0194] (Manufacturing method of crystallized glass)

[0195] The heat treatment for crystal precipitation can be carried out in one stage, or the heat treatment can be carried out at two-stage temperatures.

[0196] In the two-stage heat treatment, first, the nucleation step is carried out by heat treatment at the first temperature. After this nucleation step, the heat treatment is carried out at a second temperature higher than the nucleation step temperature, thereby carrying out the crystal growth step.

[0197] The first temperature of the two-stage heat treatment is preferably 400°C to 750°C, more preferably 450°C to 720°C, still more preferably 500°C to 680°C. Furthermore, it can also be set to 550°C to 650°C. The holding time of the first temperature is preferably 30 minutes to 2000 minutes, more preferably 180 minutes to 1440 minutes.

[0198] The second temperature of the two-stage heat treatment is preferably 550°C to 850°C, more preferably set to 600°C to 800°C. Furthermore, it can also be set to 650°C to 750°C. The holding time of the second temperature is preferably 30 minutes to 600 minutes, more preferably 60 minutes to 400 minutes.

[0199] In the one-stage heat treatment, the nucleation step and the crystal growth step are continuously carried out at the temperature of one stage. Generally, the temperature is raised until the specified heat treatment temperature, and after reaching this heat treatment temperature, the temperature is maintained for a certain period of time, and then the temperature is lowered.

[0200] In the case of carrying out the one-stage heat treatment, the heat treatment temperature is preferably 600°C to 800°C, more preferably 630°C to 770°C. Furthermore, the holding time of the heat treatment temperature is preferably 30 minutes to 500 minutes, more preferably 60 minutes to 400 minutes.

[0201] Examples

[0202] Examples 1 to 68, Comparative Examples 1 to 5

[0203] (1) Preparation of raw materials

[0204] As the raw materials of the respective components of the crystallized glass, the raw materials of the corresponding oxides are respectively selected, and these raw materials are weighed and uniformly mixed so as to become the components described in Tables 1 to 4.

[0205] (2) Manufacture of crystallized glass

[0206] Next, the mixed raw materials are put into a platinum crucible and melted in an electric furnace at 1300°C to 1600°C for two hours to 24 hours according to the meltability of the glass composition. After that, the melted glass is stirred to be homogenized, and then the temperature is lowered to 1000°C to 1450°C and cast into a mold, and slowly cooled to make the original glass.

[0207] The obtained original glass is heated under the nucleation conditions and crystallization (nucleus growth) conditions shown in Tables 5 to 8 to make the crystallized glass. In Tables 5 to 8, "-" indicates that the corresponding step is not carried out.

[0208] (3) X-ray diffraction (XRD; X-ray diffraction) measurement

[0209] The crystallized glass obtained in (2) was cut and processed to produce a measurement sample in the form of a plate with a thickness of 5 mm. For this measurement sample, in accordance with JIS K0131 (1996), using an automatic X-ray diffractometer ("D8 DISCOVER" manufactured by BRUKER Corporation) and CuKα radiation, analysis by X-ray diffraction method was carried out at intervals of 0.02° in the range of 2θ = 15° to 30°. The graph obtained by removing the background value inherent to the device from the diffraction pattern obtained was used as the X-ray diffraction spectrogram. The "background value inherent to the device" is the diffraction pattern obtained by measuring under the same conditions without using the measurement sample.

[0210] I1 to I5 in the X-ray diffraction spectrogram are shown in Tables 5 to 8. In Tables 5 to 8, "-" indicates that the corresponding peak does not exist. An example where each of I1 to I5 is "-" indicates that X-ray diffraction analysis was not performed.

[0211] Furthermore, "(I3 + I4) / (I1 + I2)" calculated from the above I1 to I4 is shown in Tables 5 to 8.

[0212] The X-ray diffraction spectrogram obtained in Example 1 is shown in Figure 2 The X-ray diffraction spectrogram obtained in Example 9 is shown in Figure 3 The X-ray diffraction spectrograms obtained in Comparative Examples 1 to 5 are respectively shown in Figures 4 to 8 . In the X-ray diffraction spectrogram, the vertical axis is intensity (counting times, unitless), and the horizontal axis is 2θ.

[0213] In addition, in all the examples where X-ray diffraction analysis was carried out, a crystalline phase derived from lithium disilicate, a crystalline phase derived from spodumene, a crystalline phase derived from β-quartz solid solution, and a crystalline phase derived from lialite were confirmed, while a crystalline phase derived from lithium metasilicate was not confirmed.

[0214] (4) Measurement of light transmittance

[0215] The crystallized glass obtained in (2) was polished and processed to produce a measurement sample in the form of a plate with a thickness of 10 mm. For this measurement sample, using a spectrophotometer ("U-4000" manufactured by Hitachi High-Technologies Corporation), the light transmittance (%) at 550 nm and the average light transmittance (%) in the range of 400 nm to 800 nm were measured. The results are shown in Tables 5 to 8. "-" indicates that this measurement was not carried out.

[0216] (5) Measurement of average linear expansion coefficient

[0217] For the crystallized glass obtained in (2) of Example 3, based on the Japan Optical Glass Industry Association Standard JOGIS08-2019 "Method for Measuring the Thermal Expansion of Optical Glasses", the average linear expansion coefficient in the range of 100 °C to 300 °C was measured.

[0218] The average linear expansion coefficient was 47×10 -7 K -1 。

[0219] [Table 1]

[0220]

[0221] [Table 2]

[0222]

[0223] [Table 3]

[0224]

[0225] [Table 4]

[0226]

[0227] [Table 5]

[0228]

[0229] [Table 6]

[0230]

[0231] [Table 7]

[0232]

[0233] [Table 8]

[0234]

[0235] As can be seen from Tables 5 to 8, in all the examples where (I3+I4) / (I1+I2) was confirmed to be 1.60 or more, excellent light transmittance was obtained. In Examples 35, 38, and Examples 41 to 51, although the crystallization of the glass was not carried out, as long as it was the raw material glass composition of these examples, by appropriately adjusting while referring to other examples etc., a crystallized glass that satisfies formula (1) and exhibits high transparency can be manufactured.

[0236] Several embodiments and / or examples of the present invention have been described in detail above. However, those with ordinary knowledge in the technical field to which the invention pertains can easily make numerous changes to these illustrated embodiments and / or examples on the premise of substantially not departing from the novel revelation and effects of the present invention. Therefore, these numerous changes are also included within the scope of the present invention.

[0237] All the content of the documents described in this specification and the content of the application that forms the basis of the priority under the Paris Convention for this case are incorporated by reference.

Claims

1. A glass containing a crystalline phase, in the X-ray diffraction spectrum obtained by X-ray diffraction method: When the diffraction intensity of the diffraction peak at the position where the diffraction angle 2θ = 23.50° to 24.00° is set as I1, the diffraction intensity of the diffraction peak at the position where the diffraction angle 2θ = 24.05° to 24.55° is set as I2, the diffraction intensity of the diffraction peak at the position where the diffraction angle 2θ = 24.60° to 25.05° is set as I3, and the diffraction intensity of the diffraction peak at the position where the diffraction angle 2θ = 25.20° to 26.60° is set as I4, (I3 + I4) / (I1 + I2) is 1.60 or more.

2. The glass containing a crystalline phase as claimed in claim 1, wherein, (I3 + I4) / (I1 + I2) is 4.50 or less.

3. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, I4 is greater than I3.

4. The glass containing a crystalline phase according to claim 1 or 2, wherein, I1 is greater than I2.

5. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, I3 is greater than I1.

6. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, I3 is greater than I2.

7. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, Among I1 to I4, I4 is the largest.

8. The glass containing a crystalline phase according to claim 1 or 2, wherein At the position where the diffraction angle 2θ = 26.60° to 27.10° in the X-ray diffraction spectrum, there is no diffraction peak.

9. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, This glass is a crystallized glass.

10. The glass containing a crystalline phase as claimed in claim 1 or 2, wherein, The composition of the original glass is in terms of mass % converted to oxides: The content of the SiO2 component is 65.0% to 85.0%; The content of the Al2O3 component is 3.0% to 15.0%; The content of the P2O5 component is more than 0% to 5.0%; The content of the Li2O component is more than 5.0% to 15.0%; The content of the ZrO2 component is 0% to 10.0%; The content of the MgO component is 0% to 5.0%.

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