Crystallized glass manufacturing method

Abstract

Provided is a crystallized glass manufacturing method, wherein a crystallized glass having an excellent appearance can be obtained by delamination when a laminate of glass for crystallization is heat-treated.　In the crystallized glass manufacturing method, a release layer containing talc is formed on at least one surface of a glass for crystallization to obtain a release layer-attached glass for crystallization, the release layer-attached glass for crystallization is laminated to produce a glass laminate for crystallization in which the release layer is disposed between adjacent pieces of the glass for crystallization, and a heat treatment for heating the glass laminate for crystallization at a temperature of 800°C or higher is performed.

Description

Manufacturing method of crystallized glass

[0001] The present invention relates to a method for producing crystallized glass.

[0002] Crystallized glass is a glass that has various excellent functions. For example, crystallized glass may show excellent strength, and is used in various applications. Crystallized glass is generally obtained by heat-treating glass of a predetermined composition. Glass that is subjected to heat treatment to obtain crystallized glass (hereinafter also referred to as "crystallization glass") may be subjected to heat treatment in a stacked state in order to improve efficiency.

[0003] Patent Document 1 discloses a glass plate having a release agent layer formed from an aqueous dispersion containing boron nitride and a colloidal inorganic binder. It also discloses that the glass plates (crystallization glass) are laminated together and subjected to a crystallization process.

[0004] International Publication No. 2020 / 018432

[0005] As described above, when the glass for crystallization is stacked and heat treated, it is often separated after heat treatment to obtain crystallized glass.Here, the present inventors have studied the method described in Patent Document 1, and found that although the crystallized glass for crystallization obtained after heat treatment can be separated from each other, there is room for improvement in the appearance of the crystallized glass obtained.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for producing crystallized glass, which, when glass for crystallization is laminated and heat-treated, results in crystallized glass having an excellent appearance when peeled off.

[0007] As a result of intensive research into the above-mentioned problems, the inventors have discovered that when talc is attached to the surface of glass to be crystallized and then the glass to be crystallized is laminated, the appearance of the crystallized glass obtained by peeling it off after heat treatment is excellent, and have arrived at the present invention.

[0008] That is, the inventors have found that the above-mentioned problems can be solved by the following configurations. [1] A method for producing glass-ceramics, comprising: obtaining glass-ceramics with a peeling layer, in which a peeling layer containing talc is formed on at least one surface of the glass-ceramics; stacking the glasses-ceramics with peeling layers to produce a glass-ceramics laminate in which the peeling layer is disposed between adjacent pairs of the glasses-ceramics; and subjecting the glass-ceramics laminate to a heat treatment by heating at a temperature of 800°C or higher. [2] A method for producing glass-ceramics according to [1], in which a slurry containing the talc is applied to at least one surface of the glass-ceramics to obtain the glass-ceramics with a peeling layer. [3] A method for producing glass-ceramics, in which the amount of talc attached to the surface of the glass-ceramics with a peeling layer is 5 to 30 mg / cm ２ [4] The method for producing crystallized glass according to any one of [1] to [3], wherein the content of solids relative to the total mass of the slurry is 1 mass % or more. [5] The method for producing crystallized glass according to any one of [1] to [4], wherein the thickness of the glass for crystallization is 1.5 mm or less. [6] The method for producing crystallized glass according to any one of [1] to [5], wherein the glass for crystallization after the heat treatment is peeled off from the glass for crystallization laminate after the heat treatment to obtain crystallized glass. [7] The composition of the glass for crystallization, expressed in mole percentage based on oxides, is: SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, Li ２ The method for producing crystallized glass according to any one of [1] to [6], wherein the glass for crystallization contains 5 to 30% of O. [8] The composition of the glass for crystallization, expressed in mole percentage based on oxides, is: SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, P ２ O ５ 0 to 5%, Li ２ 5-28% O, Na ２ O 0-4%, K ２ O 0-5%, MgO 0-10%, CaO 0-5%, ZrO２ [9] A method for producing crystallized glass according to any one of [1] to [8], wherein the crystallized glass contains one or more crystals selected from the group consisting of lithium silicate crystals and lithium aluminosilicate crystals.

[10] A method for producing crystallized glass according to any one of [1] to [9], wherein the crystallized glass contains one or more crystals selected from the group consisting of lithium disilicate crystals, β-spodumene crystals, and petalite crystals.

[0009] According to the present invention, there can be provided a method for producing crystallized glass, which, when glass to be crystallized is laminated and heat-treated, produces crystallized glass having an excellent appearance when peeled off.

[0010] 1 is a schematic cross-sectional view showing one embodiment of glass for crystallization with a peeling layer in the manufacturing method of the present invention; 2 is a schematic cross-sectional view showing one embodiment of a laminate of glasses for crystallization with a peeling layer; 3 is a schematic cross-sectional view showing one embodiment of a laminate to be subjected to heat treatment of the present invention;

[0011] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, the term "to" indicating a numerical range is used to mean that the numerical values ​​before and after the range are included as the lower and upper limits. In a glass composition, "substantially free" means that the glass composition is free of impurities other than those unavoidable in raw materials, i.e., not intentionally added. Specifically, the content of components other than those described in the glass composition is preferably less than 0.1 mol%, more preferably 0.08 mol% or less, and even more preferably 0.05 mol% or less.

[0012] In this specification, "talc" refers to talc powder. Talc has the formula Mg ３ Si ４ O １０ (OH) ２ Talc is a mineral (compound) of the formula Mg. ３ Si４ O １０ (OH) ２ The content of the compound is generally 90% by mass or more, preferably 95% by mass or more, and more preferably 99% by mass or more. ３ Si ４ O １０ (OH) ２ The content of the compound may be 100% by mass.

[0013] <Method for producing crystallized glass> The method for producing crystallized glass of the present invention comprises obtaining a crystallization glass with a peeling layer formed on at least one surface thereof, which comprises a peeling layer containing talc, laminating the crystallization glass with the peeling layer to produce a crystallization glass laminate in which a peeling layer is disposed between adjacent crystallization glasses, and then subjecting the crystallization glass laminate to a heat treatment at a temperature of 800 ° C or higher. Hereinafter, the process for obtaining a crystallization glass with a peeling layer formed on at least one surface thereof, which comprises a talc, is also referred to as a "peeling layer forming process". Hereinafter, the process for laminating crystallization glass with a peeling layer to produce a crystallization glass laminate in which a peeling layer is disposed between adjacent crystallization glasses is also referred to as a "lamination process". Hereinafter, the process for heating the crystallization glass laminate at a temperature of 800 ° C or higher is also referred to as a "heat treatment process". In addition, in the method for producing crystallization glass of the present invention, the crystallization glass may be obtained by peeling off the heat-treated crystallization glass from the heat-treated crystallization glass laminate. Hereinafter, the step of peeling off the heat-treated glass for crystallization from the heat-treated glass for crystallization laminate to obtain crystallized glass is also referred to as "peeling step". Hereinafter, each step included in the method for producing crystallized glass of the present invention and the steps that may be included in the method for producing crystallized glass of the present invention will be described in detail.

[0014] [peeling layer forming process] Peeling layer forming process is the process of obtaining the glass for crystallization with peeling layer, which comprises talc on at least one surface.That is to say, the glass for crystallization with peeling layer obtained has the peeling layer that comprises talc on at least one surface of the glass for crystallization formed.The embodiment of the glass for crystallization with peeling layer in the manufacturing method of the present invention will be described with reference to the drawing.

[0015] Fig. 1 is a cross-sectional schematic diagram showing one embodiment of glass for crystallization with a peeling layer in the manufacturing method of the present invention. The glass for crystallization with a peeling layer 10 shown in Fig. 1 is a plate-shaped glass. The glass for crystallization with a peeling layer 10 shown in Fig. 1 has a peeling layer 14 containing talc formed on one surface of the glass for crystallization 12. In the embodiment shown in Fig. 1, the peeling layer 14 is formed only on one surface of the glass for crystallization 12, but the peeling layer 14 may also be formed on the other surface of the glass for crystallization 12.

[0016] The method of obtaining the crystallization glass with peeling layer is not particularly limited, for example, the method of coating the surface of the crystallization glass with the slurry that contains talc, and the talc is attached to the surface of the crystallization glass, forming a peeling layer, and obtaining the crystallization glass with the peeling layer can be mentioned.Also, the method of coating the surface of the crystallization glass with the talc that is powder can be attached to form a peeling layer, and obtaining the crystallization glass with the peeling layer can be mentioned.Hereinafter, as an example of the peeling layer forming step, the method of coating the crystallization glass with the slurry that contains talc to obtain the crystallization glass with the peeling layer will be explained, but in the manufacturing method of the crystallization glass of the present invention, the method of obtaining the crystallization glass with the peeling layer is not limited to the above-mentioned method.

[0017] In one example of the peeling layer forming step, first, prepare a crystallization glass. The crystallization glass is preferably a plate-shaped glass. When the crystallization glass is a plate-shaped glass, the thickness of the crystallization glass is not particularly limited, but may be 0.1 mm or more, preferably 0.5 mm or more. When the crystallization glass is a plate-shaped glass, the thickness of the crystallization glass is often 2.0 mm or less, more preferably 1.5 mm or less, most preferably 1.0 mm or less. When the crystallization glass is a plate-shaped glass, the area of ​​the main surface (the surface with the largest area) is not particularly limited, but may be, for example, 0.01 m ２ The above are listed, and 0.1m ２ The area is preferably 0.5 m or more. ２In many cases, the composition is as follows. The glass for crystallization may be float glass produced by the float method, or glass produced by the roll-out method. The glass for crystallization may also be glass produced by other methods. A preferred composition of the glass for crystallization (hereinafter also referred to as "mother glass composition") will be explained below. The preferred composition of the glass for crystallization (mother glass composition) is expressed in mole percentage based on oxides, and is: SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, P ２ O ５ 0 to 5%, Li ２ It is preferable that the glass contains 5 to 30% of O. The mother glass composition of the glass for crystallization is expressed in mole percentage based on oxides as follows: SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, Li ２ It is more preferable that the O content is 5 to 30%.

[0018] Among them, the mother glass composition is expressed as mole percentage based on oxides: SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, P ２ O ５ 0 to 5%, Li ２ 5-28% O, Na ２ O 0-4%, K ２ O 0-5%, MgO 0-10%, CaO 0-5%, ZrO ２ The content of each component in the mother glass composition is preferably 0 to 5%.

[0019] SiO ２ is a component that forms the network of glass. It also increases chemical durability and reduces the occurrence of cracks when the glass surface is scratched.

[0020] SiO ２In order to improve chemical durability, the content of SiO is more preferably 63% or more, and even more preferably 65% ​​or more. ２ The content is more preferably 74.0% or less, and further preferably 72.0% or less.

[0021] Al ２ O ３ is a component that improves the ion exchange performance during chemical strengthening and increases the surface compressive stress after strengthening. It also contributes to the formation of crystals containing Al and Li. From the viewpoint of obtaining the above effects, Al ２ O ３ The content of Al is more preferably 2.5% or more, and even more preferably 3.0% or more and 3.5% or more, in that order. On the other hand, there are also cases where it is required that crystals do not grow easily during melting, that devitrification defects do not occur easily, leading to a higher yield, and that the high-temperature viscosity of the glass is reduced to make it easier to melt. From these viewpoints, Al ２ O ３ The content of is more preferably 18.0% or less, further preferably 17.0% or less, 16.0% or less, and 15.0% or less, in that order.

[0022] SiO ２ and Al ２ O ３ These are all components that stabilize the glass structure. ２ and Al ２ O ３ The total content of SiO is preferably 64.0% or more, more preferably 68.0% or more, even more preferably 72.0% or more, and particularly preferably 76.0% or more. ２ and Al ２ O ３ Both of these tend to increase the melting temperature of the glass. ２ and Al ２ O ３ The total content of is preferably 90.0% or less, more preferably 88.0% or less, and even more preferably 86.0% or less.

[0023] Li ２O is a component capable of ion exchange and improves the melting property of the glass. ２ By containing O, Li ions on the glass surface are ion-exchanged with external Na ions to be incorporated into the glass, and the incorporated Na ions are then ion-exchanged with external K ions, which makes it easy to obtain a stress profile with a large surface compressive stress and a thick compressive stress layer. ２ By including O, it is easy to obtain crystallized glass when a specific heat treatment is performed. ２ The O content is more preferably 7.0% or more, and further preferably 9.0% or more.

[0024] On the other hand, in order to reduce the crystal growth rate during glass molding and to prevent deterioration of quality due to devitrification, Li ２ The O content is more preferably 27.0% or less, further preferably 25.0% or less, particularly preferably 23.0% or less, most preferably 21.0% or less, and may be 20.0% or less.

[0025] Na ２ O and K ２ O is a component that improves the meltability of the glass and reduces the crystal growth rate during glass molding. It is also preferable to include a small amount of O in order to improve the ion exchange performance.

[0026] Na ２ O is a component that can be ion-exchanged in chemical strengthening treatment using potassium salts, and also a component that reduces the viscosity of glass. ２ The content of O is preferably 0.3% or more, more preferably 0.5% or more, and more preferably 0.8% or more, in that order. On the other hand, from the viewpoint of maintaining the glass network and avoiding a decrease in the surface compressive stress (Na_CS) in the strengthening treatment with a sodium salt, Na ２ The O content is more preferably 3.0% or less, further preferably 2.5% or less, and particularly preferably 2.3% or less.

[0027] K ２ O is a component that suppresses the rise in devitrification temperature to suppress devitrification and also improves ion exchange performance. ２The content of O is more preferably 0.03% or more, further preferably 0.05% or more, and particularly preferably 0.1% or more. On the other hand, from the viewpoint of avoiding a decrease in the surface compressive stress (K_CS) in the strengthening treatment using a sodium salt, K ２ The O content is preferably 1.0% or less, more preferably 0.8% or less, and even more preferably 0.5% or less. ２ O may not be substantially contained.

[0028] Li ２ O content, Na ２ O content and K content ２ The total content of O, R, is preferably 8.0 to 30.0%, more preferably 9.0 to 28.0%, and particularly preferably 10.0 to 25.0%, from the viewpoint of suppressing an increase in the devitrification temperature and reducing the crystal growth rate.

[0029] Li for the above R ２ The ratio of the content of O ([Li ２ O] / ([Li ２ O] + [Na ２ O] + [K ２ O]), hereinafter referred to as “Li ２ O / R ２ From the viewpoint of further improving the deep layer stress in the chemical strengthening characteristics, Li is more preferably 0.80 or more, and even more preferably 0.85 or more. ２ O / R ２ From the viewpoint of further improving chemical resistance, O is more preferably 0.99 or less, further preferably 0.98 or less, and particularly preferably 0.95 or less.

[0030] Na for the above R ２ The ratio of the content of O ([Na ２ O] / ([Li ２ O] + [Na ２ O] + [K ２ O]), hereinafter referred to as “Na ２ O / R ２ From the viewpoint of further improving the deep layer stress in the chemical strengthening characteristics, Na is preferably more than 0.00, more preferably 0.01 or more, even more preferably 0.02 or more, particularly preferably 0.05 or more, and most preferably 0.06 or more. ２O / R ２ From the viewpoint of further improving chemical resistance, O is preferably 0.40 or less, more preferably 0.30 or less, even more preferably 0.20 or less, and particularly preferably 0.10 or less.

[0031] K for the above R ２ The ratio of the content of O ([K ２ O] / ([Li ２ O] + [Na ２ O] + [K ２ O]), hereinafter referred to as “K ２ O / R ２ From the viewpoint of further increasing the electrical resistance of the glass, K is preferably 0.001 or more, more preferably 0.004 or more, and even more preferably 0.01 or more. ２ O / R ２ From the viewpoint of increasing the compressive stress near the surface in chemical strengthening properties, O is preferably 0.50 or less, more preferably 0.40 or less, further preferably 0.30 or less, and particularly preferably 0.20 or less. ２ O / R ２ O may be 0.

[0032] Also, Li ２ O / R ２ O and Na ２ O / R ２ O and K ２ O / R ２ From the viewpoint of suppressing an increase in the devitrification temperature and reducing the crystal growth rate, the product with O is preferably 0.00005 or more, more preferably 0.0001 or more, and even more preferably 0.001 or more. Moreover, the product is more preferably 0.020 or less. The product may be 0.

[0033] Al relative to the above R ２ O ３ The ratio of the content of ([Al ２ O ３ ] / ([Li ２ O] + [Na ２ O] + [K ２ O]), hereinafter referred to as “Al ２ O ３ / R ２Al is preferably 0.10 or more, more preferably 0.20 or more, even more preferably 0.50 or more, and particularly preferably 0.80 or more. ２ O ３ / R ２ O is preferably 3.00 or less, more preferably 2.00 or less, even more preferably 1.50 or less, and particularly preferably 1.30 or less.

[0034] [Al ２ O ３ ]-[Na ２ O]-[K ２ O] + [Li ２ The value represented by [0] is preferably 15.0% or more, more preferably 20.0% or more. The value is preferably 35.0% or less, more preferably 30.0% or less.

[0035] MgO may be contained to reduce viscosity during dissolution, etc. The MgO content is more preferably 0.05% or more, and even more preferably 0.08% or more. On the other hand, in order to easily increase the compressive stress layer during chemical strengthening treatment, the MgO content is more preferably 9.0% or less, and even more preferably 7.0% or less, 5.0% or less, and 3.0% or less, in that order.

[0036] Furthermore, by including MgO, it is possible to suppress the phase transition of the crystal phase from β-quartz solid solution to β-spodumene, and to suppress the precipitation of β-spodumene crystals. From the above viewpoint, it is also preferable that MgO is included in an amount of more than 0.5% and not more than 7.0%. MgO may not be substantially included.

[0037] CaO is a component that improves the meltability of glass and may be contained. The CaO content is more preferably 0.005% or more, and even more preferably 0.01% or more. On the other hand, in terms of the tendency to increase the compressive stress value during chemical strengthening treatment, the CaO content is more preferably 2.0% or less, even more preferably 1.0% or less, particularly preferably 0.8% or less, and most preferably 0.5% or less. CaO may not be substantially contained.

[0038] In order to increase the stability of the glass, it is more preferable to contain at least one of MgO and CaO, and even more preferable to contain MgO. The total content of MgO and CaO is preferably 0.01% or more, more preferably more than 0.05%, even more preferably 0.1% or more, and particularly preferably 0.2% or more. In order to further improve chemical strengthening properties, the total content of MgO and CaO is preferably 10.0% or less, more preferably 8.0% or less, 7.0% or less, 6.0% or less, 3.0% or less, and 1.0% or less, in that order.

[0039] SrO is a component that improves the meltability of glass and may be contained. The content of SrO is more preferably 0.1% or more, even more preferably 0.15% or more, and particularly preferably 0.5% or more. In order to facilitate increasing the compressive stress value during chemical strengthening treatment, the content of SrO is more preferably 3.0% or less, even more preferably 2.0% or less, particularly preferably 1.0% or less, and most preferably 0.5% or less. SrO may not be substantially contained.

[0040] BaO is a component that improves the meltability of glass and may be contained. When BaO is contained, the content is preferably 0.1% or more, more preferably 0.15% or more, and even more preferably 0.5% or more. In order to make it easier to increase the compressive stress value during chemical strengthening treatment, the content of BaO is preferably 3.0% or less, more preferably 2.0% or less, even more preferably 1.0% or less, and particularly preferably 0.5% or less. BaO may not be substantially contained.

[0041] ZnO is a component that improves the meltability of glass. The ZnO content is more preferably 0.1% or more, even more preferably 0.15% or more, and particularly preferably 0.5% or more. In order to facilitate increasing the compressive stress value during chemical strengthening treatment, the ZnO content is more preferably 3.0% or less, even more preferably 2.0% or less, particularly preferably 1.0% or less, and most preferably 0.5% or less. ZnO may not be substantially contained.

[0042] lnW is a parameter that represents the degree of oxide mixing, calculated from the contents of alkali metal oxides, alkaline earth metal oxides, and zinc oxide contained in glass. lnW is expressed by the following formula: lnW = ln(([Li ２ O] + [Na ２ O] + [K ２ O] + [MgO] + [CaO] + [SrO] + [BaO] + [ZnO])! / ([Li ２ O]! × [Na ２ O]! × [K ２ O]! × [MgO]! × [CaO]! × [SrO]! × [BaO]! × [ZnO]!)) ... Formula (W1) In formula (W1), [Li ２ O], [Na ２ O], [K ２ O], [MgO], [CaO], [SrO], [BaO] and [ZnO] are LiO, ２ O, Na ２ O.K. ２ The formula represents the content of each component of O, MgO, CaO, SrO, BaO, and ZnO expressed as mole percentage based on oxide. The symbol ! indicates a factorial of a positive integer. For example, [XO]! is the factorial of the mole percentage content of component XO expressed as mole percentage based on oxide, rounded down to the nearest integer. For example, Na ２ When O is 4.8 mol%, the calculation is made by factoring "4", that is, 4 x 3 x 2 x 1. The larger the value of lnW, the higher the degree of mixing of the above metal oxides, and the more effectively devitrification of the glass can be suppressed. From the above viewpoints, lnW is preferably 10 or more, more preferably 12 or more, even more preferably 13 or more, and particularly preferably 14 or more. lnW is preferably 20 or less, more preferably 18 or less, and even more preferably 17 or less.

[0043] TiO ２ is a component that is highly effective in suppressing solarization of glass and is a material that forms the nuclei of crystals, so it may be contained. ２ When TiO is contained, the content is preferably 0.03% or more, more preferably 0.05% or more, and further preferably 0.08% or more.２ has light absorption properties, so from the viewpoint of preventing color development of glass, TiO ２ The content of TiO is preferably 2.5% or less, more preferably 2.0% or less, further preferably 1.5% or less, and particularly preferably 1.0% or less. ２ may not be substantially included.

[0044] ZrO ２ is a component that makes it easy to increase the surface compressive stress of chemically strengthened glass-ceramics. In addition, ZrO is a material that forms the nucleus of crystals. ２ It may contain ZrO ２ The content of ZrO is more preferably more than 0%, and further preferably 0.5% or more, 1% or more, and 1.5% or more, in the following order. ２ The content is more preferably 4% or less.

[0045] P ２ O ５ P tends to increase the compressive stress layer during chemical strengthening. ２ O ５ The content of P is more preferably 0.5% or more, further preferably 1.0% or more, and particularly preferably 1.5% or more. ２ O ５ The content of is more preferably 3.0% or less. From the viewpoint of preventing the occurrence of striae during melting, it is also preferable that it is substantially not contained.

[0046] B ２ O ３ reduces the brittleness of the glass and improves the crack resistance, or improves the meltability of the glass. ２ O ３ The content of B is preferably 0.5% or more, more preferably 1.0% or more, and even more preferably 2.0% or more. ２ O ３ The content of B is preferably 8.0% or less. ２ O ３The content of is more preferably 6.0% or less, further preferably 4.0% or less, and particularly preferably 2.0% or less. From the viewpoint of preventing the occurrence of striae during melting, it is also preferable that it is substantially not contained.

[0047] Y ２ O ３ is a component that makes it easier to increase the surface compressive stress of the chemically strengthened glass-ceramics while slowing down the crystal growth rate. ２ O ３ The content of Y is preferably more than 0%, and more preferably 0.1% or more, 0.2% or more, 0.5% or more, and 0.8% or more in the following order. ２ O ３ The content of Y is more preferably 2.0% or less, and further preferably 1.5% or less. ２ O ３ may not be substantially included.

[0048] From the viewpoint of improving the initial solubility, ZrO ２ and Y ２ O ３ The total content of ZrO is more preferably 5.0% or less. ２ and Y ２ O ３ Although there is no particular lower limit for the total content, from the viewpoint of increasing the strength of the glass, it is more preferably 0.5% or more, and further preferably 1.0% or more and 1.5% or more, in that order.

[0049] ZrO ２ and Y ２ O ３ ZrO relative to the total content of ２ The ratio of the content of [ZrO ２ ] / ([ZrO ２ ]+[Y ２ O ３ ]) is more preferably 0.50 or more, further preferably 1.00 or more, and particularly preferably 2.00 or more. ２ ] / ([ZrO ２ ]+[Y ２ O ３]) is more preferably 8.00 or less, even more preferably 7.00 or less, and particularly preferably 6.00 or less.

[0050] ZrO ２ and Y ２ O ３ is known as a nucleating agent when added alone, but ZrO ２ and Y ２ O ３ By co-adding with ZrO ２ and Y ２ O ３ Since a eutectic of [ZrO ２ ] / ([ZrO ２ ]+[Y ２ O ３ By setting [ZrO ] within the above range, the diffusion of ions in the glass is suppressed, the increase in the devitrification temperature is suppressed, and devitrification can be suppressed. ２ ] / ([ZrO ２ ]+[Y ２ O ３ By setting [ZrO ] within the above range, the glass is stabilized, and further, the temperature ranges where nucleation occurs and the temperature ranges where crystal growth occurs are separated without overlapping, suppressing an increase in the crystal growth rate, and thus suppressing the occurrence of defects. ２ ] / ([ZrO ２ ]+[Y ２ O ３ By setting the temperature range at which nucleation occurs to the lower side, the decrease in the crystallization initiation temperature is suppressed, and manufacturing characteristics can be improved.

[0051] La ２ O ３ is not required, but Y ２ O ３ It can be contained for the same reasons as above. ２ O ３ is preferably 0.1% or more, more preferably 0.2% or more, further preferably 0.5% or more, particularly preferably 0.8% or more. On the other hand, if the content is too high, it becomes difficult to increase the compressive stress layer during chemical strengthening treatment. ２ O ３is preferably 5.0% or less, more preferably 3.0% or less, even more preferably 2.0% or less, and particularly preferably 1.5% or less. ２ O ３ It is also preferable that the material is substantially free of

[0052] Nb ２ O ５、 Ta ２ O ５ , Gd ２ O ３ , CeO ２ is a component that has the effect of suppressing solarization of the glass and improving meltability, and may be contained. When these components are contained, the content of each is preferably 0.03% or more, more preferably 0.1% or more, even more preferably 0.5% or more, particularly preferably 0.8% or more, and most preferably 1.0% or more. On the other hand, it is preferably 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less.

[0053] Fe ２ O ３ Since Fe absorbs heat rays, it has the effect of improving the meltability of glass, and is preferably contained when mass-producing glass using a large melting furnace. In this case, the content is preferably 0.002% or more, more preferably 0.005% or more, even more preferably 0.007% or more, and particularly preferably 0.01% or more, expressed in mass% on an oxide basis. On the other hand, Fe ２ O ３ Since an excessive content of causes coloration, from the viewpoint of enhancing the transparency of the glass, the content thereof, expressed as mass% on an oxide basis, is preferably 0.3% or less, more preferably 0.04% or less, even more preferably 0.025% or less, and particularly preferably 0.015% or less.

[0054] Furthermore, other coloring components may be added within a range that does not impede the achievement of desired chemical strengthening properties, etc. Examples of other coloring components include Co. ３ O ４ , MnO ２ , NiO, CuO, Cr ２ O ３ , V ２ O５ , Bi ２ O ３ , SeO ２ , Er ２ O ３ , Nd ２ O ３ The following are suitable examples.

[0055] SO is used as a fining agent when melting glass. ３ , chloride, fluoride, etc. may be contained as appropriate. ２ O ３ It is preferable that Sb is not contained. ２ O ３ When SnO is contained, it is preferably 0.3% or less, more preferably 0.1% or less, and most preferably not contained. ２ The content of SnO is more preferably 0.1% or more, further preferably 0.2% or more, and particularly preferably 0.3% or more. ２ In order to suppress the occurrence of defects, the content is preferably 1.5% or less, and more preferably 1.2% or less.

[0056] In one example of the peeling layer forming process, a slurry containing talc is applied to the prepared glass for crystallization. In this specification, the term "slurry" refers to a mixture containing a solvent and particles. The solid content contained in the slurry includes talc. The average particle size of the talc is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. The average particle size of the talc is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. The solid content of the slurry may include solid content other than talc (other solid content), and the other solid content may include silica (SiO ２) crystals. The solid content refers to components that do not volatilize during the heat treatment process described below. The solvent contained in the slurry is not particularly limited, and known solvents can be used. Examples of the solvent include water, methanol, ethanol, isopropyl alcohol (2-propanol, IPA), acetone, and methyl ethyl ketone (2-butanone), with water or ethanol being preferred. The slurry may also contain components (other components) other than those described above. Examples of other components include dispersants, surfactants, and binders. In the slurry, the content of solids relative to the total mass of the slurry (solid content concentration) is preferably 1% by mass or more, more preferably 2% by mass or more, and most preferably 4% by mass or more. The solid content concentration is often 20% by mass or less, more preferably 15% by mass or less, particularly preferably 10% by mass or less, and most preferably 7% by mass or less.

[0057] The method for applying the slurry to the glass for crystallization is not particularly limited, and examples thereof include dip coating, spin coating, flow coating (e.g., curtain coating), roll coating, bar coating, blade coating, slit coating, nozzle coating, spray coating, and inkjet coating. Alternatively, the slurry may be applied by contacting a brush or the like impregnated with the slurry with the surface of the glass for crystallization. After the slurry has been applied to the glass for crystallization, a treatment for removing the solvent contained in the slurry may be performed. The method for removing the solvent contained in the slurry is not particularly limited, and examples thereof include heat drying, vacuum drying, and natural drying.

[0058] When the slurry is applied to the glass for crystallization as described above, the talc adheres to the surface of the glass for crystallization, forming a release layer, and thus glass for crystallization with a release layer is obtained.

[0059] The amount of talc attached to the crystallization glass with the release layer is 3 mg / cm ２ More than 5 mg / cm is preferred. ２ More preferably, 10 mg / cm or more ２The amount of talc attached to the glass for crystallization with a release layer is more preferably 30 mg / cm. ２ Preferably, 25 mg / cm or less ２ More preferably, 20 mg / cm or less ２ The amount of boron nitride attached to the glass for crystallization with a peeling layer is more preferably 10 mg / cm. ２ Preferably, less than 5 mg / cm ２ More preferably, 1 mg / cm or less ２ The amount of boron nitride attached to the glass for crystallization with a release layer is more preferably 0 mg / cm ２ In other words, it is also preferable that the release layer of the glass for crystallization with a release layer does not contain boron nitride. Boron nitride has a high melting point and hardness, and therefore is likely to cause irregularities on the surface of the glass whose viscosity has been reduced in the subsequent heat treatment step, which is likely to cause waviness.

[0060] [Lamination process] Lamination process is the process of laminating the glass for crystallization with peeling layer to prepare the glass for crystallization laminate, in which peeling layer is arranged between adjacent glass for crystallization.That is, in lamination process, the glass for crystallization with peeling layer is laminated so that peeling layer is arranged between the glass for crystallization.The state of the state in which the glass for crystallization with peeling layer is laminated will be explained with reference to the drawing.

[0061] Fig. 2 is a cross-sectional schematic diagram showing one embodiment of a laminated state of glass for crystallization with a peeling layer. The glass for crystallization laminate 20 shown in Fig. 2 is a laminate of three sheets of glass for crystallization with a peeling layer 10 obtained in the above-mentioned peeling layer forming step. In the glass for crystallization laminate 20, a peeling layer 14 is arranged between each of the three sheets of glass for crystallization 12. In the embodiment shown in Fig. 2, one peeling layer 14 is arranged between the glass for crystallization 12, but two or more peeling layers 14 may be arranged between the glass for crystallization 12. In addition, in the embodiment shown in Fig. 2, no peeling layer 14 is arranged on the surface of the glass for crystallization 10 arranged at the bottom in the paper, but a peeling layer 14 may be arranged.

[0062] In the embodiment shown in Fig. 2, the number of laminated sheets of glass for crystallization 10 with a peeling layer is three, but this may be changed as appropriate. The number of laminated sheets of glass for crystallization 10 with a peeling layer may be, for example, two, four or more, five or more, or ten or more. There is no particular upper limit to the number of laminated sheets, but it is preferable to adjust the number of laminated sheets so that the total mass of the laminated glass for crystallization 10 is 30 kg or less. If the total mass of the laminated glass for crystallization 18 is 30 kg or less, the glass for crystallization 18 arranged below is less likely to break.

[0063] The method for carrying out the lamination step is not particularly limited, and for example, the method of laminating the glasses for crystallization with the peeling layer obtained in the peeling layer forming step in order with the surface on which the peeling layer is formed facing upward can be mentioned. In addition, when laminating, the lamination position of the upper glass may be shifted relative to the lower glass, so as to be used as a gripping portion when peeling.

[0064] [Heat Treatment Step] In the heat treatment step, the glass laminate for crystallization is subjected to a heat treatment at a temperature of 800°C or higher. By performing the heat treatment step, the glass for crystallization in the glass laminate for crystallization is crystallized. The heat treatment step may include a treatment of heating at a temperature of 800°C or higher (hereinafter also referred to as "high-temperature heat treatment"), and may also include a treatment of heating at a temperature below 800°C (hereinafter also referred to as "low-temperature heat treatment"). The heat treatment step can be performed, for example, by heating the laminate of the embodiment shown in Figure 3.

[0065] Fig. 3 is a cross-sectional schematic diagram showing one embodiment of a laminate to be subjected to a heat treatment process. The laminate 30 shown in Fig. 3 has, in this order, a first setter plate 22, a glass laminate for crystallization 20, a second setter plate 24, and a support 26. The glass laminate for crystallization 20 is similar to the glass laminate for crystallization described in Fig. 2 , and therefore a description thereof will be omitted. The support 26 supports the glass laminate for crystallization 20 and facilitates transportation, etc. Furthermore, the arrangement of the first setter plate 22 and the second setter plate 24 makes it difficult for the glass for crystallization 12 in the glass laminate for crystallization 20 to shift position.

[0066] 3, any one or more of the first setter plate 22, the second setter plate 24, and the support 26 may be omitted. The first setter plate 22, the second setter plate 24, and the support 26 are preferably formed of a known heat-resistant material.

[0067] In the heat treatment process, heating is carried out at a temperature of 800 ° C or more, and by heating at 800 ° C or more, the talc contained in the peeling layer melts or the talc is easily deformed.In addition, when heating is carried out in the heat treatment process, the crystallization glass is also easily deformed, but the talc particles are also easily deformed, so the crystallization glass is not easily deformed due to the shape of the talc particles, and the smoothness of the surface of the crystallization glass is easily increased.As a result, the crystallization glass obtained by the crystallization glass manufacturing method of the present invention is considered to have excellent appearance when peeled off.In addition, because talc is arranged between the crystallization glass, the crystallization glass is easily peeled off when the peeling process is carried out at the latter stage.

[0068] In the heat treatment process, the treatment (high-temperature heat treatment) is carried out at a temperature of 800 ° C or more, and the heating temperature in the high-temperature heat treatment can be appropriately adjusted according to the type of crystals to be precipitated in the glass for crystallization.For example, the heating temperature in the high-temperature heat treatment can be 850 ° C or more, or 900 ° C or more.The temperature of the heat treatment in the high-temperature heat treatment is usually 1100 ° C or less.The heating time of the high-temperature heat treatment can be, for example, 0.2 hours or more, preferably 0.5 hours or more, more preferably 1 hour or more, and particularly preferably 1.5 hours or more.In addition, the heating time of the high-temperature heat treatment can be 12 hours or less, preferably 6 hours or less, more preferably 4 hours or less.

[0069] Furthermore, as described above, the heat treatment step may include a treatment (low-temperature heat treatment) in which heating is performed at a temperature below 800°C. The low-temperature heat treatment is preferably performed before the high-temperature heat treatment. More specifically, it is preferable to perform the low-temperature heat treatment on the glass for crystallization and then perform the high-temperature heat treatment. The low-temperature heat treatment generates crystal nuclei in the glass for crystallization, while the high-temperature heat treatment facilitates the growth of the crystal nuclei. The heating temperature in the low-temperature heat treatment can be appropriately adjusted depending on the type of crystals to be precipitated in the glass for crystallization. For example, the heating temperature in the low-temperature heat treatment may be 500°C or higher, preferably 600°C or higher, and more preferably 700°C or higher. The heating temperature in the low-temperature heat treatment may be less than 800°C and 795°C or lower. The heating time in the low-temperature heat treatment may be, for example, 0.5 hours or more, preferably 1 hour or more, and more preferably 2 hours or more. The heating time in the low-temperature heat treatment may be 12 hours or less, preferably 8 hours or less, and more preferably 6 hours or less.

[0070] The type of crystal contained in the obtained crystallized glass is not particularly limited, but for example, one or more crystals selected from the group consisting of lithium silicate crystals, lithium aluminosilicate crystals, and lithium phosphate crystals are preferred, and one or more crystals selected from the group consisting of lithium silicate crystals and lithium aluminosilicate crystals are more preferred. As the lithium silicate crystals, lithium metasilicate (Li ２ SiO ３ ) crystal, lithium disilicate crystal (Li ２ Si ２ O ５ As the lithium phosphate crystal, lithium orthophosphate crystal (Li ３ P.O. ４ As the lithium aluminosilicate crystal, β-spodumene crystal (LiAlSi ２ O ６ ), petalite crystals (LiAlSi ４ O １０) is preferred. The resulting crystallized glass also preferably contains one or more crystals selected from the group consisting of lithium disilicate crystals, β-spodumene crystals, and petalite crystals. Examples of crystals contained in the resulting crystallized glass include β-quartz solid solution, magnesium-containing crystals, and zirconium-containing crystals.

[0071] The crystallization rate of the resulting crystallized glass is preferably 10% or more, more preferably 15% or more, even more preferably 20% or more, and particularly preferably 25% or more, in terms of improving mechanical strength. Furthermore, in order to increase transparency, it is preferably 70% or less, more preferably 60% or less, and even more preferably 50% or less. A small crystallization rate is also advantageous in that it is easy to heat and bend. The crystallization rate can be calculated from X-ray diffraction intensity by the Rietveld method. The Rietveld method is described in "Crystal Analysis Handbook," edited by the Editorial Committee of the Crystallographic Society of Japan (Kyoritsu Shuppan, 1999, pp. 492-499).

[0072] The average particle size of the precipitated crystals of the obtained crystallized glass is preferably 300 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, and particularly preferably 100 nm or less, in order to improve transparency. The average particle size of the precipitated crystals can be determined from a transmission electron microscope (TEM) image. It can also be estimated from a scanning electron microscope (SEM) image.

[0073] In the heat treatment step, the temperature increase rate when changing the temperature can be adjusted as appropriate, but is, for example, 1°C / min or more, preferably 3°C / min or more. The temperature increase rate is, for example, 10°C / min or less. The atmosphere in the heat treatment step is not particularly limited, and may be an inert gas atmosphere or an air atmosphere.

[0074] The heat treatment step can be carried out in a known heat treatment furnace or the like. The type of the heat treatment furnace is not particularly limited, and may be a batch type or a continuous type. The heating type of the heat treatment furnace is also not particularly limited, and may be a combustion heating type or an electric heating type.

[0075] [Peeling step] In the manufacturing method of crystallized glass of the present invention, a peeling step may be carried out. In the peeling step, the crystallized glass after heat treatment is peeled off from the crystallized glass laminate after heat treatment to obtain crystallized glass. As mentioned above, in the manufacturing of the crystallized glass of the present invention, talc is arranged between the crystallized glass as a peeling layer, so that the crystallized crystallized glass is easy to peel off from each other even after heat treatment. When the peeling step is carried out, the crystallized glass is obtained by crystallizing the above-mentioned crystallized glass. The peeling step can be carried out by a known method, and for example, the crystallized glass of the crystallized glass laminate after heat treatment is pulled in a direction approximately parallel to the lamination direction, and the crystallized crystallized glass is peeled off.

[0076] [Cutting step] The manufacturing method of the crystallized glass of the present invention may have a step of cutting the crystallized glass obtained into desired size. That is, the crystallized glass obtained may be cut. There is no particular limitation on the cutting method, and it can be cut by a known method. There is no particular limitation on the size of the crystallized glass cut, and it can be cut into desired size.

[0077] [Other steps] The method for producing crystallized glass of the present invention may have other steps than those mentioned above.For example, it may have a chamfering step of chamfering the cut crystallized glass.It may also have a forming step of bending the obtained crystallized glass.It may also have a polishing step of polishing the surface of the obtained crystallized glass.In the polishing step, it is also preferable that the peeling layer formed on the surface of the glass for crystallization is removed.In addition, the crystallized glass obtained by the method for producing crystallized glass of the present invention has excellent appearance, so it is easy to shorten the polishing time required to obtain desired surface roughness, and it is easy to reduce the cost of performing the polishing step.

[0078] Furthermore, the crystallized glass obtained by the method for producing crystallized glass of the present invention may be subjected to a chemical strengthening treatment. That is, the method for producing crystallized glass of the present invention may include a chemical strengthening treatment step in which the obtained crystallized glass is chemically strengthened. The chemical strengthening treatment step can be carried out by a known method. For example, the chemical strengthening treatment is carried out by contacting the crystallized glass with a molten salt of a metal salt (e.g., potassium nitrate or sodium nitrate) containing a metal ion with a large ionic radius (typically, K ion or Na ion). The contact between the crystallized glass and the molten salt of the metal salt is carried out, for example, by immersing the crystallized glass in the molten salt of the metal salt. Upon contact between the crystallized glass and the metal salt, metal ions with a small ionic radius (typically, Na ion or Li ion) in the crystallized glass are replaced with metal ions with a large ionic radius (typically, K ion for Na ion, and Na ion or K ion for Li ion). Examples of the molten salt include a molten salt containing at least one of sodium nitrate and potassium nitrate. The chemical strengthening treatment may be carried out in two or more stages.

[0079] <Applications> The crystallized glass obtained by the crystallized glass manufacturing method of the present invention can be used in a variety of applications. In particular, the crystallized glass obtained is useful as a cover glass. The cover glass can also be suitably used for purposes such as surface protection of displays, sensors, and solar cell modules. In particular, the crystallized glass that has been chemically strengthened is useful as a cover glass for mobile devices such as mobile phones, smartphones, personal digital assistants (PDAs), and tablet terminals. Furthermore, it is useful as a cover glass for non-portable devices such as various centers, cover glass for display devices such as televisions (TVs), personal computers (PCs), and touch panels, cover glass for the surface of solar cell modules, elevator walls, wall surfaces (full-surface displays) of buildings such as houses and buildings, building materials such as window glass, tabletops, and interiors of automobiles and airplanes. It is also useful as a cover glass for the above-mentioned items. Furthermore, it can be used for applications such as curved housings by bending.

[0080] The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the examples shown below. Note that Example 1 described below is an example, and Example 2 described below is a comparative example.

[0081] Example 1 First, glass raw materials were mixed and melted to obtain the glass compositions shown in Table 1, expressed in mole percentages based on oxides, and a glass plate having a thickness of 0.6 mm was obtained by the float method. The obtained glass plate was cut into a size of 50 mm x 50 mm to prepare glass for crystallization. The oxides, hydroxides, carbonates, nitrates, etc. used as the glass raw materials were appropriately selected from commonly used glass raw materials.

[0082] [Glass composition] SiO ２ : 70.00% Al ２ O ３ : 14.15% P ２ O ５ : 1.50% Li ２ O: 10.05% Na ２ O: 1.00% K ２ O: 0.50% MgO: 0.10% CaO: 0.10% TiO ２ : 0.10% ZrO ２ : 1.50% SnO ２ : 1.00%

[0083] Next, the following slurry was applied to the obtained glass plate, which was the glass for crystallization, to obtain glass for crystallization with a release layer. The slurry was applied to one side of the glass for crystallization by a coating method using a cotton swab. The amount of the slurry applied was such that the amount of talc after heat drying was 10 mg / cm. ２ It was adjusted so that

[0084] [Slurry composition] Talc (Kosakai Pharmaceutical Co., Ltd.): 5 g Solvent: water 100 g

[0085] Next, ten sheets of the obtained glass for crystallization with a peeling layer were stacked in order with the peeling layer facing upward to obtain a glass for crystallization laminate. The obtained glass for crystallization laminate was further placed on an alumina plate as a support to obtain a laminate, and the laminate was introduced into a heat treatment furnace (MBK furnace manufactured by Tokyo Motoyama Shokai Co., Ltd.).

[0086] The heat treatment in the heat treatment furnace was carried out at 790°C for 4 hours (corresponding to the above-mentioned low-temperature heat treatment), followed by heat treatment at 920°C for 3 hours (corresponding to the above-mentioned high-temperature heat treatment). The temperature increase rate and temperature decrease rate were controlled to 5°C / min. The heat treatment in the heat treatment furnace was carried out in an air atmosphere.

[0087] The crystallized glass for crystallization was peeled off one by one from the heat-treated glass for crystallization laminate to obtain crystallized glass. ２ O ６ ) crystals were precipitated, and the crystallization rate was 70%. In the above procedure, the crystallized glass could be peeled off one by one. The crystallized glass obtained by the procedure of Example 1 had no cloudiness on the surface and had an excellent appearance. The type of crystals precipitated in the crystallized glass and the crystallization rate were identified by powder X-ray diffraction measurement under the following conditions. - Measurement device: SmartLab manufactured by Rigaku Corporation - X-rays used: CuKα rays - Measurement range: 2θ = 10 to 80° - Scan speed: 10° / min - Scan step: 0.02°

[0088] <Example 2> In the procedure of above-mentioned Example 1, except that the slurry to be applied is changed to the following slurry, the glass for crystallization with peeling layer is laminated in the same manner as in Example 1, and heat treatment is carried out to obtain crystallized glass.In the procedure of Example 2, crystallized glass can be peeled off one by one.However, the crystallized glass obtained by the procedure of Example 2 has cloudiness on the surface, and compared with the crystallized glass obtained by the procedure of Example 1, its appearance is inferior.

[0089] [Slurry] Boron nitride (Boron spray manufactured by Kaken Tech Co., Ltd.)

[0090] In the step of Example 1, when the slurry was not applied, cracks occurred when the crystallized glass for crystallization was peeled off from the heat-treated laminate of glass for crystallization.

[0091] From the above results, it was confirmed that when glass for crystallization with a peeling layer having a peeling layer containing talc formed on at least one surface is obtained, and the glass for crystallization with a peeling layer is laminated to produce a glass for crystallization laminate in which a peeling layer is arranged between adjacent glass for crystallization, and the glass for crystallization laminate is subjected to heat treatment by heating at a temperature of 800°C or higher, the appearance of the crystallized glass obtained by peeling it off is excellent.

[0092] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2024-114047, filed on July 17, 2024, are incorporated herein by reference as part of the disclosure of the present invention.

[0093] REFERENCE SIGNS LIST 10 Glass for crystallization with release layer 12 Glass for crystallization 14 Release layer 20 Glass for crystallization laminate 22 First setter plate 24 Second setter plate 26 Support 30 Laminate

Claims

1. A method for producing crystallized glass, comprising: obtaining glass for crystallization with a peeling layer, in which a peeling layer containing talc is formed on at least one surface of the glass for crystallization; stacking the glass for crystallization with the peeling layer to produce a glass for crystallization laminate in which the peeling layer is disposed between adjacent pieces of the glass for crystallization; and heat-treating the glass for crystallization laminate at a temperature of 800°C or higher.

2. The method for producing crystallized glass according to claim 1, wherein the glass to be crystallized with the peeling layer is obtained by applying a slurry containing the talc to at least one surface of the glass to be crystallized.

3. The amount of the talc attached to the surface of the glass for crystallization with the release layer is 5 to 30 mg / cm ２ 3. The method for producing crystallized glass according to claim 1, wherein 4. The method for producing crystallized glass according to claim 2, wherein the content of solids in the slurry is 1% by mass or more relative to the total mass of the slurry.

5. The method for producing crystallized glass according to claim 1 or 2, wherein the thickness of the glass to be crystallized is 1.5 mm or less.

6. The method for producing crystallized glass according to claim 1 or 2, wherein the heat-treated glass for crystallization is peeled off from the heat-treated glass for crystallization laminate to obtain crystallized glass.

7. The composition of the glass for crystallization is, in mole percentage on an oxide basis, SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, Li ２ 3. The method for producing crystallized glass according to claim 1, wherein the glass contains 5 to 30% of O.

8. The composition of the glass for crystallization is, in mole percentage on an oxide basis, SiO ２ 60 to 75% Al ２ O ３ 2 to 20%, P ２ O ５ 0 to 5%, Li ２ 5-28% O, Na ２ O 0-4%, K ２ O 0-5%, MgO 0-10%, CaO 0-5%, ZrO ２ 3. The method for producing crystallized glass according to claim 1, wherein the glass contains 0 to 5% of 9. A method for producing crystallized glass, wherein the crystallized glass obtained by the method for producing crystallized glass according to claim 1 or 2 contains one or more crystals selected from the group consisting of lithium silicate crystals and lithium aluminosilicate crystals.

10. A method for producing crystallized glass, wherein the crystallized glass obtained by the method for producing crystallized glass according to claim 1 or 2 contains one or more crystals selected from the group consisting of lithium disilicate crystals, β-spodumene crystals, and petalite crystals.

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