JP2016060650A - Li2O-Al2O3-SiO2-BASED CRYSTALLIZATION GLASS AND MANUFACTURING METHOD THEREFOR - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a LiO-AlO-SiO-based crystallization glass suitable for a counter substrate or a dust proof substrate of a liquid crystal display element inside a liquid crystal projector because its thermal expansion coefficient matches with that of quartz glass and its transparency is high, and a manufacturing method therefor.SOLUTION: A β-quartz solid solution body is deposited as a main crystal and mol% ratio of the SiOcontent in the β-quartz solid solution body is 2.5 to 3.3. It preferably contains, as a glass composition by mass%, SiO55 to 75%, AlO15 to 25%, LiO 2 to 5%, NaO 0 to 1%, KO 0 to 1%, MgO 0 to 3%, BaO 0 to 2%, TiO1 to 3%, ZrO0 to 3%, TiO+ZrO3 to 5%, PO0 to 3%, and SnO0.1 to 0.5%.SELECTED DRAWING: None

Description

The present invention relates to production of Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass and Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass used for a counter substrate for liquid crystal panel and a dustproof substrate for liquid crystal panel. Regarding the method. More specifically, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass and Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass having a thermal expansion coefficient matching that of quartz glass and high transparency are obtained. It relates to the manufacturing method.

Conventionally, Li ₂ O—Al ₂ O ₃ —SiO ₂ based low expansion crystallized glass has been used for various applications such as oil, firewood, other stove front windows, setters for firing electronic components, top plates for electromagnetic cookers, etc. It has been.

This type of Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass is, for example, a β-quartz solid solution (Li ₂ O · Al ₂ O) as a main crystal as disclosed in Patent Documents 1 to 3. ₃ · _{nSiO 2} precipitated the proviso 2 ≦ n ≦ 4]), the thermal expansion coefficient of -1~ + 1 × ^{10 -7} / ℃ about a crystal glass or β- spodumene solid solution _(Li 2 O · _Al 2 O ₃ · nSiO ₂ [where n ≧ 4]) is precipitated, and a crystallized glass having a thermal expansion coefficient of around 10 × 10 ⁻⁷ / ° C. is known.

Japanese Examined Patent Publication No. 39-21049 Japanese Patent Publication No. 40-20182 JP-A-1-308845

  A liquid crystal projector is commercially available as one of video display devices. One of the members constituting the liquid crystal projector is a liquid crystal display element. The liquid crystal display element includes a driving substrate and a counter substrate that are opposed to each other with a liquid crystal interposed therebetween, and a dust-proof substrate that is bonded to these substrates via a transparent resin. The dustproof substrate is a glass for defocusing so that foreign matter is not projected onto the surface of the display element when it is projected.

  Since the temperature of the liquid crystal is several hundred degrees or more during projector operation, the drive substrate is required to have very high heat resistance. Further, when the substrate is thermally expanded due to a temperature rise, distortion occurs and causes a phase difference. As a result, display unevenness occurs. In order to prevent this display unevenness, the drive substrate, the counter substrate, and the dust-proof substrate are required to have a low thermal expansion coefficient, and quartz glass is used.

In recent years, the use of Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass as a counter substrate or a dust-proof substrate constituting a liquid crystal display element inside a liquid crystal projector has been studied. However, the conventional Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass does not match the thermal expansion coefficient of quartz glass used as a drive substrate, and adheres to quartz glass via a transparent resin. Later, the glass may be bent, degrading the image quality of the liquid crystal projector. The thermal expansion coefficient of quartz glass is, for example, about 5.8 × 10 ⁻⁷ / ° C. at 30 to 300 ° C.

From the viewpoint of ensuring transparency, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass in which β-quartz solid solution is precipitated as the main crystal is selected, but the thermal expansion coefficient is matched with that of quartz glass. For this reason, when a part of the β-quartz solid solution precipitated as the main crystal is crystallized to the β-spodumene solid solution, there is a problem that the transparency is greatly lowered.

An object of the present invention is that Li ₂ O—Al ₂ O ₃ —SiO suitable for a counter substrate and a dust-proof substrate of a liquid crystal display element inside a liquid crystal projector because the thermal expansion coefficient matches that of quartz glass and has high transparency. It is to provide a _two- system crystallized glass and a manufacturing method thereof.

As a result of intensive studies to achieve the above object, the present inventors have obtained β-quartz solid solution, which is the main crystal, in order to obtain a thermal expansion coefficient matched to quartz glass without transferring it to β-spodumene. - found that is possible to adjust the mole% ratio of SiO ₂ content of quartz solid solution within a certain range is important, it is to propose a present invention.

That, _{Li 2 O-Al 2 O 3} -SiO 2 based crystallized glass of the present invention, there is provided a _{Li 2 O-Al 2 O 3} -SiO 2 based crystallized glass as main crystals β- quartz solid solution, The molar ratio of the SiO ₂ content in β-quartz solid solution is 2.5 to 3.3. Here, “β-quartz solid solution is precipitated as the main crystal” means that among the precipitated crystals, the crystal having the largest amount of precipitation by weight ratio is β-quartz solid solution, and crystals other than β-quartz solid solution. This does not exclude the precipitation of. “Mole% ratio of SiO ₂ content in β-quartz solid solution” means X based on (406) plane of β-quartz solid solution precipitated on Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass. is a value corresponding a ray diffraction peak angle (2 [Theta]) in n value of _{Li 2 O · Al 2 O 3} · nSiO 2 calculated by the lattice constant method. Details of the lattice constant method are described in the literature, and details are omitted here (for example, Iwatsuki, Tanaka, Fukasawa, analysis of β-eucryptite solid solution in crystallized glass by the lattice constant method, Nippon Kagaku (Journal, 1974, No. 3, 505-510).

The higher the mol% ratio of the SiO ₂ content in the β-quartz solid solution, the closer the thermal expansion coefficient is to zero. Further, the higher the molar ratio, the higher the possibility that a part of the β-quartz solid solution is transferred to the β-spodumene solid solution. Therefore, in the present invention, the mol% ratio of the SiO ₂ content in the β-quartz solid solution is limited to the above range. By adopting this configuration, it is possible to obtain a crystallized glass having a thermal expansion coefficient matching that of quartz glass and having excellent transparency, and as an alternative material for quartz glass used as a counter substrate and a dustproof substrate. Can be used.

In the present invention, in mass% as a glass _{composition, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 2~5%, Na 2 O 0~1%, K 2 O 0~1 %, MgO 0 to 3%, BaO 0 to 2%, TiO ₂ 1 to 3%, ZrO ₂ 0 to 3%, TiO ₂ + ZrO ₂ 3 to 5%, P ₂ O ₅ 0 to 3%, SnO ₂ 0. It is preferable to contain 1 to 0.5%. Here, “TiO ₂ + ZrO ₂ ” means the total amount of TiO ₂ content and ZrO ₂ content.

By employing the above configuration, it is the molar% ratio of SiO ₂ content of β- quartz solid solution easy to obtain a tunable crystallized glass to a desired value. Moreover, it can be set as the crystallized glass excellent in characteristics, such as chemical durability and mechanical strength.

In the present invention, the thermal expansion coefficient at 30 to 300 ° C. is preferably 1 × 10 ^{−7 to} 9 × 10 ⁻⁷ / ° C. Here, the thermal expansion coefficient means a linear thermal expansion coefficient.

  In the present invention, the transmittance at a thickness of 1.1 mm and a wavelength of 400 nm is preferably 70% or more.

The method for producing Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention comprises the steps of preparing crystalline glass having the property of precipitating β-quartz solid solution as a main crystal, and β-quartz solid solution And a step of crystallizing the crystalline glass under a heat treatment condition in which the molar ratio of SiO ₂ content is 2.5 to 3.3. Here, “crystalline glass” refers to an amorphous glass having the property of precipitating crystals from the glass matrix by heat treatment.

  According to the above configuration, crystallized glass having a thermal expansion coefficient matching that of quartz glass and having excellent transparency can be easily obtained.

Hereinafter, the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention will be described. In the following description, “%” means “mass%” unless otherwise specified.

In the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention, the main crystal is a β-quartz solid solution, and the mol% ratio of the SiO ₂ content in the β-quartz solid solution is 2.5 to It is characterized by 3.3. A preferred range for the molar percentage of the SiO ₂ content in the β-quartz solid solution is 2.7 to 3.2, in particular 2.8 to 3.2.

When the molar ratio of the SiO ₂ content in the β-quartz solid solution is too low, the thermal expansion coefficient of the crystallized glass becomes too high and it is difficult to match the thermal expansion coefficient of the quartz glass. Moreover, it becomes easy to phase-separate. When phase separation occurs, the transmittance of the glass decreases. When the mole% ratio of the SiO ₂ content is too high, the thermal expansion coefficient of the crystallized glass becomes too low to match the thermal expansion coefficient of the quartz glass. For this reason, when the mol% ratio of the SiO ₂ content in the β-quartz solid solution is out of the predetermined range, when used as a counter substrate of the liquid crystal display element inside the liquid crystal projector, the glass is adhered when bonded via a transparent resin. It will be curved. In addition, when the molar ratio of the SiO ₂ content is too high, there is a high possibility that a part of the β-quartz solid solution is transferred to the β-spodumene solid solution. When transitioning to a β-spodumene solid solution, the transparency of the crystallized glass is greatly reduced.

The Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention is not limited in the glass composition as long as a β-quartz solid solution is precipitated. For example, as a glass composition, SiO ₂ 55 _{~75%, Al 2 O 3 15~25} %, Li 2 O 2~5%, Na 2 O 0~1%, K 2 O 0~1%, 0~3% MgO, BaO 0~2%, TiO _{2 1~3%, ZrO 2 0~3%} , TiO 2 + ZrO 2 3~5%, P 2 O 5 0~3%, Li 2 O-Al 2 containing SnO 2 0.1 to 0.5% O ₃ —SiO ₂ -based crystallized glass is preferable. The reason for specifying the content of each component as described above will be described below.

SiO ₂ is a component that forms a glass skeleton and constitutes a Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal. The SiO ₂ content is preferably 55 to 75%, 58 to 70%, particularly preferably 60 to 68%. When the content of SiO ₂ is _{small, Li 2 O-Al 2 O} 3 -SiO 2 based crystal is less likely precipitate, consisting of thermal expansion coefficient hardly aligned with the quartz glass. In addition, chemical durability tends to decrease. On the other hand, when the content of SiO ₂ is large, the meltability of the glass is lowered, the viscosity of the glass melt is increased, and it tends to be difficult to clarify or to form the glass.

Al ₂ O ₃ is a component that forms a glass skeleton and constitutes a Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal. The content of Al ₂ O ₃ is preferably 15 to 25%, 18 to 25%, particularly 20 to 24%. When the content of Al ₂ O ₃ is small, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals are difficult to precipitate, and it is difficult to match the thermal expansion coefficient with quartz glass. In addition, chemical durability tends to decrease. On the other hand, when the content of Al ₂ O ₃ is large, lowered the meltability of the glass, higher viscosity of the glass melt tends to molding becomes difficult in the glass may become difficult to clear. Further, the mullite crystals tend to precipitate and the glass tends to devitrify, and the glass is easily damaged.

Li ₂ O is a component that constitutes Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals, greatly affects the crystallinity, and lowers the viscosity of the glass to improve the meltability and moldability of the glass. It is a component to be made. The content of Li ₂ O is preferably 2 to 5%, 3 to 5%, particularly 3.5 to 4%. The content of Li ₂ O is _{less, Li 2 O-Al 2 O} 3 -SiO 2 based crystal is less likely precipitate, consisting of thermal expansion coefficient hardly aligned with the quartz glass. Further, the glass is devitrified during crystallization, and the transparency is easily lowered. Furthermore, there is a tendency that the meltability of the glass is lowered, or the viscosity of the glass melt is increased to make it difficult to clarify or to form the glass. On the other hand, too strong crystallinity is high content of Li 2 _O, there is a tendency that the glass transparency devitrified tends to decrease.

Na ₂ O is a component that dissolves in the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal, greatly affects the crystallinity, and lowers the viscosity of the glass to improve the meltability and moldability of the glass. It is a component to improve. The content of Na ₂ O is preferably 0 to 1%, particularly preferably 0 to 0.8%. And Na 2 _O with a high content becomes too strong crystallinity, tend to glass transparency devitrified tends to decrease.

K ₂ O is a component that dissolves in the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal, greatly affects the crystallinity, lowers the viscosity of the glass, and improves the meltability and moldability of the glass. It is a component to improve. The content of K ₂ O is preferably 0 to 1%, particularly preferably 0 to 0.8%. And K 2 _O with high content becomes too strong crystallinity, tend to glass transparency devitrified it tends to decrease.

MgO is a component having an effect of increasing the thermal expansion coefficient of the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal by being dissolved in the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal. The content of MgO is preferably 0 to 3%, 0.1 to 2%, particularly preferably 0.1 to 1.5%. When the content of MgO is large, the crystallinity becomes too strong and tends to devitrify, and the glass tends to be broken. Further, the glass tends to be colored and the transparency tends to decrease.

  BaO is a component that lowers the viscosity of the glass and improves the meltability and moldability of the glass. The BaO content is preferably 0 to 2%, 0.5 to 1.8%, particularly preferably 1 to 1.5%. When there is much content of BaO, the crystal | crystallization containing Ba will precipitate easily and it will become easy to devitrify glass.

TiO ₂ is a component that serves as a nucleating agent for precipitating crystals in the crystallization step. The content of TiO ₂ is preferably 1 to 3%, 1.5 to 3%, particularly preferably 1.5 to 2.5%. If the content of TiO ₂ is large, the coloring of the glass tends to increase. Moreover, it becomes easy to devitrify glass and transparency will fall easily. On the other hand, when the content of TiO ₂ is small, crystal nuclei are not sufficiently formed, coarse crystals are deposited, the glass becomes cloudy, and the transparency tends to be lowered. In addition, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals are less likely to precipitate, making it difficult to match the thermal expansion coefficient with quartz glass.

ZrO ₂ is a nucleation component for precipitating crystals in the crystallization step, like TiO ₂ . The content of ZrO ₂ is preferably 0 to 3%, 0.5 to 2.5%, particularly preferably 1 to 2.5%. When the content of ZrO ₂ is large, easily devitrified when melted glass, molding of the glass is difficult. Further, during the crystallization, coarse crystals containing Zr are precipitated, and the glass becomes cloudy, and the transparency tends to be lowered.

The content of TiO ₂ + ZrO ₂ is preferably 3 to 5%, 3.5 to 5%, particularly 4 to 5%. When the content of TiO ₂ + ZrO ₂ is small, crystal nuclei are not sufficiently formed, coarse crystals are precipitated, the glass becomes cloudy, and the transparency tends to be lowered. In addition, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals are less likely to precipitate, making it difficult to match the thermal expansion coefficient with quartz glass. When the high content of TiO 2 ₊ ZrO _2, glass during crystallization devitrified, transparency tends to decrease.

P ₂ O ₅ is a component that promotes the phase separation of glass and assists the formation of crystal nuclei. The content of P ₂ O ₅ is preferably 0 to 3%, 0.5 to 3%, particularly preferably 1 to 2%. When the content of P ₂ O ₅ is large, the glass tends to undergo phase separation in the melting step, the homogeneity of the glass decreases, tend to be opaque. Further, the glass becomes cloudy during crystallization, and the transparency tends to decrease.

SnO ₂ is a component that acts as a fining agent. Moreover, when it contains abundantly, it is also a component which strengthens coloring of glass. The SnO ₂ content is preferably 0.1 to 0.5%, 0.1 to 0.4%, particularly preferably 0.15 to 0.35%. When the content of SnO ₂ is small, it becomes difficult to clarify the glass. Glass is colored and the content of SnO ₂ is larger, the transparency tends to decrease.

Fe ₂ O ₃ is a component mixed as an impurity, and a component that enhances the coloring of the glass. The content of Fe ₂ O ₃ is preferably 0.003 to 0.02%, 0.003 to 0.018%, and particularly preferably 0.003 to 0.015%. When the content of Fe ₂ O ₃ is large, the coloring of the glass becomes transparency decreases strongly. The smaller the content of Fe ₂ O _3, the more preferable it is because coloring can be suppressed, but for example, it is necessary to use an expensive high-purity raw material in order to make the range less than 0.003%, which increases the manufacturing cost. End up.

_{Li 2 O-Al 2 O 3} -SiO 2 based crystallized glass of the present invention may contain various components other than the above components. For example _{H 2, CO 2, CO,} H 2 O, He, Ne, Ar, may contain minor components such as _{N 2} to 0.1%, respectively. Further, noble metal elements such as Ag, Au, Pd, and Ir may be added up to 10 ppm in the glass.

Furthermore, as long as there is no adverse effect on transparency, the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystallized glass of the present invention is B ₂ O ₃ , CaO, SrO, ZnO, Cr ₂ O ₃ , Sb ₂ O ₃ , SO ₃ , MnO, CeO ₂ , Cl ₂ , La ₂ O ₃ , WO ₃ , Nd ₂ O ₃ , Nb ₂ O ₅ , Y ₂ O _{3 and the} like may be contained up to 2% in total.

The Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystallized glass of the present invention has a thermal expansion coefficient at 30 to 300 ° C. of 1 × 10 ⁻⁷ / ° C. to 9 × 10 ⁻⁷ / ° C., preferably 2. 5 is a × ^{10 -7} /℃~7.5×10 ^-7 / ℃. If the thermal expansion coefficient at 30 to 300 ° C. is lower than 1 × 10 ⁻⁷ / ° C. or higher than 10 × 10 ⁻⁷ / ° C., the thermal expansion coefficient does not match that of quartz glass, and the liquid crystal display inside the liquid crystal projector When used as a counter substrate or the like of an element, the glass tends to be bent when bonded through a transparent resin.

The Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention has a thickness of 1.1 mm and a transmittance at a wavelength of 400 nm of 70% or more, preferably 75% or more. If the transmittance at a thickness of 1.1 mm and a wavelength of 400 nm is lower than 70%, the transparency of the glass is lowered.

Next, a method for producing the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass of the present invention will be described.

First, a crystalline glass having a property of precipitating β-quartz solid solution as a main crystal is prepared. The glass composition of the crystallizable glass, for example by _{mass%, SiO 2 55~75%, Al} 2 O 3 15~25%, Li 2 O 2~5%, Na 2 O 0~1%, K 2 O 0 ˜1%, MgO 0 to 3%, BaO 0 to 2%, TiO ₂ 1 to 3%, ZrO ₂ 0 to 3%, TiO ₂ + ZrO ₂ 3 to 5%, P ₂ O ₅ 0 to 3%, SnO ₂ It is preferable to use a material containing 0.1 to 0.5%. The reason why the composition range is limited as described above is as described above, and the description is omitted here. This type of crystalline glass can be obtained by charging a raw material batch prepared to have a desired composition into a glass melting furnace, melting at 1500 to 1750 ° C., and then molding.

Next, the crystalline glass is crystallized under heat treatment conditions in which the molar ratio of the SiO ₂ content of the β-quartz solid solution precipitated as the main crystal is 2.5 to 3.3. The mol% ratio of the SiO ₂ content of the β-quartz solid solution is also affected by the glass composition, but if the glass composition is the same, it can be reduced as the heat treatment temperature is lowered and the heat treatment time is shortened. As specific heat treatment conditions, for example, it is preferably 5 to 100 minutes at 780 to 830 ° C., more preferably 5 to 30 minutes at 800 to 830 ° C. In order to increase the transmittance of the crystallized glass obtained, it is preferable to suppress the crystal transition from the β-quartz solid solution to the β-spodumene solid solution as much as possible. In order to suppress the crystal transition to the β-spodumene solid solution, it is effective to lower the heat treatment temperature or shorten the heat treatment time.

In this way it is possible to obtain a _{Li 2 O-Al 2 O 3} -SiO 2 based crystallized glass of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to a following example.

(Examples 1-3 and Comparative Examples 1-2)
First, by mass%, SiO ₂ 65.7%, Al ₂ O ₃ 22.2%, Li ₂ O 3.7%, Na ₂ O 0.4%, K ₂ O 0.3%, MgO 0.7%, BaO 1.2%, TiO ₂ 2.0%, ZrO ₂ 2.2%, P ₂ O ₅ 1.4%, SnO ₂ 0.2%, Fe ₂ O ₃ 0.011% Each raw material was prepared in the form of oxide, hydroxide, carbonate, nitrate, etc. to obtain a glass batch. The resulting glass batch was melted at 1680 ° C. for 20 hours. After melting, the glass was roll-formed to a thickness of 4 mm, and further cooled to room temperature using a slow cooling furnace to obtain crystalline glass.

The crystalline glass was subjected to nucleation by heat treatment at 770 to 790 ° C. for 1 hour, and then subjected to heat treatment under the heat treatment conditions shown in Table 1 for crystallization. About the obtained crystallized glass, the molar ratio of the SiO ₂ content in the precipitated crystal and β-quartz solid solution, the thermal expansion coefficient, and the transmittance were measured.

  The precipitated crystal was identified from the X-ray diffraction peak by the powder method. X-ray diffraction peak measurement was performed using RINT2000 manufactured by Rigaku Corporation.

The mol% ratio of SiO ₂ content in β-quartz solid solution was calculated from the X-ray diffraction peak angle of (406) plane of β-quartz solid solution by the powder method using the lattice constant method. X-ray diffraction angle measurement was performed using RINT2000 manufactured by Rigaku Corporation.

  The transmittance was evaluated based on the transmittance at a wavelength of 400 nm measured using a spectrophotometer for a crystallized glass plate that was optically polished on both sides to a thickness of 1.1 mm. A spectrophotometer V-670 manufactured by JASCO was used for the measurement.

  The thermal expansion coefficient was evaluated by an average linear thermal expansion coefficient measured in a temperature range of 30 to 300 ° C. using a crystallized glass sample processed to 20 mm × 3.8 mmφ. A diatzometer made by NETZSCH was used for the measurement.

As is apparent from Table 1, the crystallized glass of Examples 1 to 3 has a coefficient of thermal expansion in the range of 2.6 × 10 ^{−7 to} 6.1 × 10 ⁻⁷ / ° C., and has a thickness of 1.1 mm. The transmittance at a wavelength of 400 nm was 77% or more.

_{Li 2 O-Al 2 O 3} -SiO 2 based crystallized glass of the present invention is suitable for a counter substrate and dustproof substrate of the liquid crystal display element in the liquid crystal projector.

Claims (5)

Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass whose main crystal is β-quartz solid solution, and the mol% ratio of the SiO ₂ content of β-quartz solid solution is 2.5 to 3.3 Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystallized glass characterized by being. In mass% as a glass _{composition, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 2~5%, Na 2 O 0~1%, K 2 O 0~1%, MgO 0~ _{3%, BaO 0~2%, TiO} 2 1~3%, ZrO 2 0~3%, TiO 2 + ZrO 2 3~5%, P 2 O 5 0~3%, SnO 2 0.1~0.5 % Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystallized glass according to claim 1. 30-300 thermal expansion coefficient of 1 × ¹⁰ at ℃ ^-7 ~9 × ¹⁰ -7 / ° C. is characterized according to claim 1 or 2 in _{Li 2 O-Al 2 O 3} -SiO 2 based crystal according Glass. Thickness _{1.1mm, Li 2 O-Al 2} O 3 -SiO 2 based crystallized glass according to any one of claims 1 to 3, the transmittance at a wavelength of 400nm is equal to or less than 70%. The step of preparing crystalline glass having the property of precipitating β-quartz solid solution as the main crystal and the above-mentioned crystal under the heat treatment conditions in which the molar percentage of SiO ₂ content of β-quartz solid solution is 2.5 to 3.3 And a step of crystallizing the crystalline glass. A method for producing Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystallized glass.