阅读说明：本技术 Li2O－Al2O3－SiO2系结晶化玻璃 (Li2O－Al2O3－SiO2Crystallized glass of system ) 是由 横田裕基 于 2020-03-18 设计创作，主要内容包括：本发明提供一种紫外～红外域的透过性高且不易破裂的Li-(2)O－Al-(2)O-(3)－SiO-(2)系结晶化玻璃。该Li-(2)O－Al-(2)O-(3)－SiO-(2)系结晶化玻璃的特征在于,以质量％计含有40～90％的SiO-(2)、1～10％的Li-(2)O、5～30％的Al-(2)O-(3)、0～20％的SnO-(2)、超过0％且为20％以下的ZrO-(2)、0％以上且低于2％的TiO-(2)、0～10％的MgO、0～10％的P-(2)O-(5),作为主结晶析出有β－锂辉石固溶体。(The invention provides Li with high permeability in ultraviolet-infrared region and difficult cracking 2 O－Al 2 O 3 －SiO 2 A crystallized glass. The Li 2 O－Al 2 O 3 －SiO 2 The crystallized glass is characterized by containing 40-90% by mass of SiO 2 1 to 10% of Li 2 O, 5-30% of Al 2 O 3 0 to 20 percent of SnO 2 ZrO in an amount of more than 0% and not more than 20% 2 TiO of 0% or more and less than 2% 2 0 to 10% of MgO and 0 to 10% of P 2 O 5 A β -spodumene solid solution precipitates as a main crystal.)

1. Li₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains 40 to 90 mass% of SiO₂1 to 10% of Li₂O, 5-30% of Al₂O₃0 to 20 percent of SnO₂ZrO in an amount of more than 0% and not more than 20%₂TiO of 0% or more and less than 2%₂0 to 10% of MgO and 0 to 10% of P₂O₅A β -spodumene solid solution precipitates as a main crystal.

2. Li according to claim 1₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that: further contains 0 to 10 mass% of Na₂O, 0 to 10% of K₂O, 0-10% CaO, 0-10% SrO, 0-10% BaO, 0-10% ZnO, 0-10% B₂O₃。

3. Li according to claim 1 or 2₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

0 to 2 mass% of SnO₂。

4. Li according to any one of claims 1 to 3₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains 1.5 to 20 mass% of ZrO₂And MgO in an amount exceeding 0% and not more than 10%.

5. Li according to any one of claims 1 to 4₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

further contains 0.10% or less of Fe by mass%₂O₃。

6. As claimed in any one of claims 1 to 5One item of said Li₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

MgO/(Li) in terms of mass ratio₂O + MgO) is 0.0001 or more.

7. Li according to any one of claims 1 to 6₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

by mass ratio, Al₂O₃/(SnO₂+ZrO₂) Is 9 or less.

8. Li according to any one of claims 1 to 7₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

SnO by mass ratio₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) Is 0.01 or more.

9. Li according to any one of claims 1 to 8₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

in terms of mass ratio, ZrO₂/Li₂O is 0.4 or more.

10. Li according to any one of claims 1 to 9₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

in terms of mass ratio, (SnO₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) Is 0.03 or more.

11. Li according to any one of claims 1 to 10₂O－Al₂O₃－SiO₂Crystallized glass of system, whichIs characterized in that:

in terms of mass ratio, (SiO)₂+Al₂O₃)/Li₂O is 20 or more.

12. Li according to any one of claims 1 to 11₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

in terms of mass ratio, (Li)₂O+Na₂O+K₂O)/ZrO₂Is 3.0 or less.

13. Li according to any one of claims 1 to 12₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

in terms of mass ratio, TiO₂/ZrO₂0.0001 to 5.0.

14. Li according to any one of claims 1 to 13₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

in terms of mass ratio, TiO₂/(TiO₂+Fe₂O₃) 0.001 to 0.999.

15. Li according to any one of claims 1 to 14₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains HfO in an amount of less than 0.05 mass%₂+Ta₂O₅。

16. Li according to any one of claims 1 to 15₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains 7ppm or less of Pt in terms of mass%.

17. Li according to any one of claims 1 to 16₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains Rh in an amount of 7ppm or less in terms of mass%.

18. Li according to any one of claims 1 to 17₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

contains 9ppm or less of Pt + Rh in terms of mass%.

19. Li according to any one of claims 1 to 18₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

a coefficient of thermal expansion of-20 x 10 at 20 to 200 DEG C^－7/℃～30×10^－7/℃。

20. Li as claimed in any one of claims 1 to 19₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

the coefficient of thermal expansion at 20-380 ℃ is-20 x 10^－7/℃～30×10^－7/℃。

21. Li according to any one of claims 1 to 20₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

the coefficient of thermal expansion at 20 to 750 ℃ is-20 x 10^－7/℃～30×10^－7/℃。

22. Li according to any one of claims 1 to 21₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

the appearance was colorless.

23. Li according to any one of claims 1 to 22₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

a transmittance of 1% or more at a wavelength of 360nm and a thickness of 2 mm.

24. Li according to any one of claims 1 to 23₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

a transmittance of 10% or more at a wavelength of 555nm and a thickness of 2 mm.

25. Li according to any one of claims 1 to 24₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

a transmittance of 35% or more at a wavelength of 1070nm and a thickness of 2 mm.

26. Li₂O－Al₂O₃－SiO₂A crystallized glass system, characterized in that:

a thickness of 2mm, a transmittance of 1% or more at a wavelength of 360nm, and a coefficient of thermal expansion of-20 x 10 at 20 to 200 DEG C^－7/℃～30×10^－7At/° c, a β -spodumene solid solution precipitates as a main crystal.

Technical Field

The invention relates to Li₂O－Al₂O₃－SiO₂A crystallized glass.

Background

In recent years, portable electronic devices such as cellular phones, notebook Personal computers, and PDAs (Personal Data Assistance) are required to be downsized and lightened. Accordingly, the mounting space of the semiconductor chips used in these electronic devices is also severely limited, and high-density mounting of the semiconductor chips is a problem. Thus, a three-dimensional mounting technique is used, in which semiconductor chips are stacked on each other and wiring is connected between the semiconductor chips, thereby achieving high-density mounting of semiconductor packages.

As shown in patent document 1, a fan-out (fan out) type Wafer Level Package (WLP) includes: a step of molding (molding) a plurality of semiconductor chips with a sealing material of resin to form a processing substrate, and then wiring on one surface of the processing substrate; a step of forming solder bumps, and the like. These steps are accompanied by a heat treatment at about 200 ℃, and therefore, the sealing material may be deformed, and the processed substrate may be changed in dimension. In order to suppress dimensional changes of the processing substrate, it is effective to use a support substrate for supporting the processing substrate, and in order to effectively suppress dimensional changes of the processing substrate with relatively low expansion, low expansion characteristics are sometimes required for the support substrate.

Then, a β -quartz solid solution (Li) belonging to a low expansion crystal precipitated as a main crystal is studied₂O·Al₂O₃·nSiO₂[ wherein n is 2. ltoreq. n.ltoreq.4]) Beta-spodumene solid solution (Li)₂O·Al₂O₃·nSiO₂[ wherein n.gtoreq.4]) Equal Li₂O－Al₂O₃－SiO₂Crystalline Li₂O－Al₂O₃－SiO₂The crystallized glass is used as a supporting substrate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-113341

Disclosure of Invention

Technical problem to be solved by the invention

However, for precipitating a solid solution of β -quartz as a main crystalLi₂O－Al₂O₃－SiO₂The crystallized glass has a problem that the volume shrinkage at the time of crystal precipitation from the mother glass is large, and cracks such as surface peeling and cracks are likely to occur. In addition, Li in which a β -spodumene solid solution is precipitated as a main crystal₂O－Al₂O₃－SiO₂Although the crystallized glass of this type has a small volume shrinkage during crystallization and is less likely to crack, it has a problem that the laser light (ultraviolet light to infrared light) used for fixing and separating the processing substrate and the glass substrate is less likely to transmit because of its low ultraviolet to infrared region permeability.

The purpose of the present invention is to provide Li which has high permeability in the ultraviolet to infrared region and is less likely to break₂O－Al₂O₃－SiO₂A crystallized glass.

Technical solution for solving technical problem

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is characterized by containing 40-90% by mass of SiO₂1 to 10% of Li₂O, 5-30% of Al₂O₃0 to 20 percent of SnO₂ZrO in an amount of more than 0% and not more than 20%₂TiO of 0% or more and less than 2%₂0 to 10% of MgO and 0 to 10% of P₂O₅A β -spodumene solid solution precipitates as a main crystal. Li precipitated with solid solution of beta-spodumene₂O－Al₂O₃－SiO₂In the crystallized glass, the β -spodumene solid solution has a large crystal grain size of about 500nm, and light is easily scattered, and thus the ultraviolet to infrared light transmittance tends to be low. However, it has been found that by making TiO₂The content of (b) is reduced to less than 2% by mass, and the reduction in light transmittance due to scattering of light can be sufficiently compensated for. Further, it relates to Li which precipitates a solid solution of β -spodumene as a main crystal₂O－Al₂O₃－SiO₂The crystallized glass has a small volume shrinkage when crystals are precipitated from mother glass, and is less likely to crack.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably further contains 0 to 10% by mass of Na₂O, 0 to 10% of K₂O, 0-10% CaO, 0-10% SrO, 0-10% BaO, 0-10% ZnO, 0-10% B₂O₃。

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains 0 to 2 mass% of SnO₂。

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains ZrO in an amount of 1.5 to 20% by mass₂And MgO in an amount exceeding 0% and not more than 10%.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably further contains 0.10% or less by mass of Fe₂O₃。

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably MgO/(Li) in mass ratio₂O + MgO) is 0.0001 or more. Wherein, MgO/(Li)₂O + MgO) "means that the content of MgO is divided by Li₂The total amount of O and MgO.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably composed of Al in a mass ratio₂O₃/(SnO₂+ZrO₂) Is 9 or less. Wherein "Al₂O₃/(SnO₂+ZrO₂) "means Al₂O₃Is divided by SnO₂And ZrO₂The total amount of (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably SnO by mass ratio₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) Is 0.01 or more. Wherein "SnO₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) "means SnO₂Is divided by SnO₂、TiO₂、ZrO₂、P₂O₅And B₂O₃The total amount of (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystalline glass is preferably ZrO in a mass ratio₂/Li₂O is 0.4 or more. Wherein "ZrO₂/Li₂O "means ZrO₂Is divided by Li₂The value obtained for the O content.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably composed of (SnO)₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) Is 0.03 or more. Wherein, "(SnO)₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) "means SnO₂、ZrO₂And TiO₂Is divided by SiO₂、Al₂O₃、Li₂O、Na₂O、K₂O、MgO、CaO、SrO、BaO、ZnO、B₂O₃And P₂O₅The total amount of (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably composed of (SiO) in a mass ratio₂+Al₂O₃)/Li₂O is 20 or more. Wherein, "(SiO)₂+Al₂O₃)/Li₂O "means SiO₂And Al₂O₃Is divided by Li₂The value obtained for the O content.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably composed of (Li) in a mass ratio₂O+Na₂O+K₂O)/ZrO₂Is 3.0 or less. Wherein, "(Li)₂O+Na₂O+K₂O)/ZrO₂By "means Li₂O、Na₂O and K₂The total amount of O divided by ZrO₂The value obtained by (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably TiO by mass ratio₂/ZrO₂0.0001 to 5.0. Wherein, the "TiO₂/ZrO₂"means TiO₂Is divided by ZrO₂The value obtained by (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably TiO by mass ratio₂/(TiO₂+Fe₂O₃) 0.001 to 0.999. Wherein, the "TiO₂/(TiO₂+Fe₂O₃) "means TiO₂Is divided by TiO₂And Fe₂O₃The value obtained by (a).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains HfO in an amount of less than 0.05 mass%₂+Ta₂O₅. Wherein "HfO₂+Ta₂O₅"means HfO₂And Ta₂O₅The total amount of (a) and (b).

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains not more than 7ppm by mass of Pt.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains 7ppm or less of Rh in terms of mass%.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass preferably contains 9ppm or less of Pt + Rh in terms of mass%. Wherein "Pt + Rh" means the total amount of Pt and Rh.

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 200 ℃ is preferably-20X 10^－7/℃～30×10^－7V. C. This makes it possible to be suitably used for various applications requiring low expansibility.

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 380 ℃ is preferably-20 x 10^－7/℃～30×10^－7/℃。

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 750 ℃ is preferably-20X 10^－7/℃～30×10^－7V. C. This makes it possible to be suitably used for various applications requiring low expansibility over a wide temperature range.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is preferably colorless in appearance.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass is preferably 1% or more at a thickness of 2mm and a wavelength of 360 nm. This makes it possible to be suitably used for various applications requiring ultraviolet transmittance.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass is preferably 10% or more at a thickness of 2mm and a wavelength of 555 nm. This makes it possible to be suitably used for various applications requiring visible light transmittance.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass is preferably 35% or more at a thickness of 2mm and a wavelength of 1070 nm. This makes it possible to be suitably used for various applications requiring infrared transmittance.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass is characterized by having a transmittance of 1% or more at a wavelength of 360nm and a thermal expansion coefficient of-20X 10 at 20 to 200 ℃ in a thickness of 2mm^－7/℃～30×10^－7At/° c, a β -spodumene solid solution precipitates as a main crystal.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a transparent material having high transparency in the ultraviolet to infrared regions and being free from defectsEasily breakable Li₂O－Al₂O₃－SiO₂A crystallized glass.

Detailed Description

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass contains 40-90% by mass of SiO₂1 to 10% of Li₂O, 5-30% of Al₂O₃0 to 20 percent of SnO₂ZrO in an amount of more than 0% and not more than 20%₂TiO of 0% or more and less than 2%₂0 to 10% of MgO and 0 to 10% of P₂O₅A β -spodumene solid solution precipitates as a main crystal.

First, the reason why the glass composition is limited as described above is shown below. In the following description of the content of each component, "%" means "% by mass" unless otherwise specified.

SiO₂Is formed into a skeleton of glass and forms Li₂O－Al₂O₃－SiO₂Is a crystalline component. SiO 2₂The content of (b) is preferably 40-90%, 45-85%, 50-85%, 51-84%, 52-83%, 53-82%, 54-81%, 55-80%, 55-78%, 55-75%, 55-73%, 55-72%, 55-71%, 55-70%, 56-70%, 57-70%, 58-70%, 59-70%, 60-70%, 61-69%, 62-68%, 63-67%, and particularly preferably 64-66%. SiO 2₂When the content of (b) is too small, the thermal expansion coefficient tends to be high, and it is difficult to obtain crystallized glass having excellent thermal shock resistance. Further, the chemical durability tends to be lowered. On the other hand, SiO₂When the content (b) is too large, the meltability of the glass is lowered, the viscosity of the glass melt is increased, and thus the glass is difficult to be clarified, the glass is difficult to be molded, and the productivity is liable to be lowered. Further, the time required for crystallization becomes long, and the productivity tends to be lowered.

Li₂O is constituent Li₂O－Al₂O₃－SiO₂The component of the system crystal greatly affects the crystallinity, lowers the viscosity of the glass, and improves the meltability and the moldability of the glassThe composition of (1). Li₂The content of O is preferably 1 to 10%, 2 to 9%, 2 to 8%, 2 to 7%, 2 to 6%, 2.1 to 6%, 2.2 to 6%, 2.3 to 6%, 2.4 to 6%, 2.5 to 5%, 2.5 to 4.9%, 2.5 to 4.8%, 2.5 to 4.7%, 2.5 to 4.6%, 2.5 to 4.5%, 2.6 to 4.4%, 2.7 to 4.3%, 2.8 to 4.2%, 2.9 to 4.1%, 3 to 4%, 3.1 to 3.9%, and particularly preferably 3.2 to 3.8%. Li₂When the content of O is too small, mullite crystals tend to precipitate and the glass tends to devitrify. And, when crystallizing the glass, Li₂O－Al₂O₃－SiO₂The crystals are less likely to precipitate, and it is difficult to obtain crystallized glass having excellent thermal shock resistance. Further, the meltability of the glass is lowered, the viscosity of the glass melt is increased, and the glass melt is difficult to be clarified, and the glass is difficult to be molded, so that the productivity is liable to be lowered. In another aspect. Li₂When the content of O is too large, the crystallinity becomes too strong, and the glass tends to be devitrified, and the crystallized glass is easily broken.

Al₂O₃Is formed into a skeleton of glass and forms Li₂O－Al₂O₃－SiO₂Is a crystalline component. And, Al₂O₃Or a component coordinated around the crystal nucleus to form a core-shell structure. By the presence of the core-shell structure, the crystal nucleus component is not easily supplied from the outside of the shell, the crystal nucleus is not easily enlarged, and a plurality of minute crystal nuclei are easily formed. Al (Al)₂O₃The content of (b) is preferably 5-30%, 6-30%, 7-29%, 8-29%, 9-28%, 10-28%, 11-28%, 12-27%, 13-27%, 14-26%, 15-26%, 16-26%, 16.5-25.5%, 17-25%, 17.5-25%, 18-24.5%, 18-24%, 18.5-24%, 19-24%, 19.5-23.5%, 20-23.5%, 20.5-23%, and particularly preferably 21-22.5%. Al (Al)₂O₃When the content of (b) is too small, the thermal expansion coefficient tends to be high, and it is difficult to obtain crystallized glass having excellent thermal shock resistance. Further, the chemical durability tends to be lowered. Moreover, the crystal nuclei become large and the junctions become largeCrystallized glass is likely to be clouded. In another aspect. Al (Al)₂O₃When the content (b) is too large, the meltability of the glass is lowered, the viscosity of the glass melt is increased, and thus the glass is difficult to be clarified, the glass is difficult to be molded, and the productivity is liable to be lowered. Further, mullite crystals tend to precipitate to devitrify the glass, and the crystallized glass tends to be easily broken.

SiO₂、Al₂O₃、Li₂O is a main constituent of a β -spodumene solid solution as a main crystal and a β -quartz solid solution as a precursor thereof, Li₂O and Al₂O₃By compensating charges with each other, solid solubility in SiO₂And (3) a framework. By containing the above three components in an appropriate ratio, crystallization proceeds efficiently and the production can be performed at low cost. Thus, (SiO)₂+Al₂O₃)/Li₂O is preferably 20 or more, 20.2 or more, 20.4 or more, 20.6 or more, 20.8 or more, and particularly preferably 21 or more.

SnO₂Is a component that functions as a clarifying agent. And is also a nucleating component for precipitating crystals in the crystallization step. On the other hand, the glass contains a large amount of components which may significantly increase the coloring of the glass. SnO₂The content of (b) is preferably 0 to 20%, 0 to 18%, 0 to 16%, 0 to 14%, 0 to 12%, 0 to 10%, 0 to 8%, more than 0% and not more than 8%, 0.01 to 7%, 0.01 to 6%, 0.01 to 5%, 0.01 to 4%, 0.05 to 3.9%, 0.05 to 3.8%, 0.05 to 3.7%, 0.05 to 3.6%, 0.05 to 3.5%, 0.05 to 3.4%, 0.05 to 3.3%, 0.05 to 3.2%, 0.05 to 3.1%, 0.05 to 3%, 0.05 to 2.9%, 0.05 to 2.8%, 0.05 to 2.7%, 0.05 to 2.6%, 0.05 to 2.5%, 0.05 to 2.4%, 0.05 to 2.3%, 0.05 to 2.2.2%, 0.05 to 2.2%, and particularly preferably 0.05 to 2.2%. SnO₂When the content of (3) is too large, the coloring of the crystallized glass becomes strong. In addition, the raw material batch becomes expensive, and as a result, the production cost becomes high.

ZrO₂Is a nucleating component for precipitating crystals in the crystallization step. ZrO (ZrO)₂The content of (B) is preferably more than 0% and 20% or less and more than 0%And 18% or less, more than 0% and 16% or less, more than 0% and 14% or less, more than 0% and 12% or less, more than 0% and 10% or less, more than 0% and 9% or less, more than 0% and 8% or less, more than 0% and 7% or less, more than 0% and 6% or less, more than 0% and 5.5% or less, more than 0% and 5% or less, more than 0% and 4.9% or less, 0.1 to 4.9%, 0.2 to 4.9%, 0.3 to 4.9%, 0.4 to 4.9%, 0.5 to 4.9%, 0.6 to 4.9%, 0.7 to 4.9%, 0.8 to 4.9%, 0.9 to 4.9%, 1 to 4.9%, 1.1 to 4.9%, 1.2 to 4.9%, 1.3 to 4.9%, 1.4.9%, 1.9 to 4.9%, 1.9%, 1.2 to 4.9%, 1.9%, 1.3 to 4.9%, 1.9% to 4.9%, 1.9%, 1.4.9%, 1.9% to 4.9%, 1.9%, 1.4.9%, 1.9%, 4.4.9%, 1.9% to 4.9%, 1.4.9% to 4.9%, 1.9%, 1.4.9% to 4.9%, 1.9%, 4.9%, 1.9% to 4.9%, 4.9% to 4.9%, 1.9% to 4.9%, 1.9%, 4.9%, 1.9% to 4.9%, 1.9% to 4.9%, 4.9% to 4.9%, 1.9%, 4.9%, 1.9% to 4.9% to 4.4.9%, 1.9%, 4.9%, 1.9% to 4.9%, 1.9%, 4.9% to 4.9%, 1.9% to 4.9%, 4.4.9%, 4.9% to 4.9%, 1.9%, 4.9% to 4.9%, 4.9% to 4.9%, 1.9% to 4.4.9% to 4.9%, 1.9%, 4.9%, 1.9% to 4.9%, 1.9%, 4.9% to 4.9%, 4.9% to 4.9%, 1.9%, 4.9%, 1.9%, 1., 2.7 to 4.9%, more than 2.7% and 4.9% or less, 2.8 to 4.9%, 3.0 to 4.8%, 3.1 to 4.7%, 3.2 to 4.6%, 3.3 to 4.5%, 3.4 to 4.4%, 3.5 to 4.3%, particularly preferably 3.6 to 4.2%. ZrO (ZrO)₂When the content of (b) is too small, crystal nuclei cannot be sufficiently formed, coarse crystals precipitate, and the glass may be clouded and broken. In another aspect. ZrO (ZrO)₂When the content of (A) is too large, coarse ZrO precipitates₂The glass is easily devitrified by crystallization, and the crystallized glass is easily broken. Further, the raw material batch becomes expensive, and as a result, the production cost becomes high.

ZrO₂Functioning as a refractory nucleating agent, Li₂O functions as a flux for promoting melting, and is therefore present in ZrO₂/Li₂O hours, ZrO can be efficiently melted₂. On the other hand, in ZrO₂/Li₂When O is too small, the low-temperature viscosity is excessively reduced, and the glass tends to flow in a nucleation step in which heat treatment is performed at a relatively low temperature, thereby causing deformation. Further, the low-temperature viscosity is excessively lowered, and the nucleation rate becomes excessively high, so that the control of the nucleation step may become difficult. Thus, ZrO₂/Li₂O is preferably 0.4 or more, 0.42 or more, 0.44 or more, 0.46 or more, 0.48 or more, 0.50 or more, 0.52 or more, 0.53 or more, 0.54 or more, 0.55 or more, 0.56 or more, and particularly preferably 0.57 or more. In ZrO₂/Li₂When O is too large, ZrO of refractory nature₂The resin composition is not sufficiently melted and tends to remain as devitrified pits. Thus, ZrO₂/Li₂The upper limit of O is preferably 4 or less.

SnO₂+ZrO₂Preferably more than 0% and 30% or less, 0.5 to 25%, 1 to 20%, 1.2 to 17.5%, 1.8 to 15%, 2 to 12.5%, 2.1 to 10%, 2.2 to 10%, 2.3 to 9.5%, 2.4 to 9%, 2.5 to 8.5%, 2.7 to 8%, 2.9 to 7.5%, 3.1 to 7.5%, 3.2 to 7.5%, 3.3 to 7.5%, 3.4 to 7.5%, particularly preferably 3.5 to 7.5%. At SnO₂+ZrO₂If the amount is too small, crystal nuclei are less likely to precipitate and crystallization becomes difficult. On the other hand, in SnO₂+ZrO₂If the amount is too large, crystal nuclei become large, and the crystallized glass tends to be cloudy.

In addition, Al₂O₃/(SnO₂+ZrO₂) Preferably 9 or less, 8.9 or less, 8.8 or less, 8.7 or less, 8.6 or less, 8.5 or less, 8.4 or less, 8.3 or less, 8.2 or less, 8.1 or less, 8 or less, 7.9 or less, 7.8 or less, 7.7 or less, 7.6 or less, 7.5 or less, 7.4 or less, 7.3 or less, 7.2 or less, 7 or less, 6.9 or less, 6.8 or less, 6.7 or less, 6.6 or less, 6.5 or less, 6.4 or less, 6.3 or less, 6.2 or less, 6.1 or less, 6 or less, 5.9 or less, 5.8 or less, 5.7 or less, 5.6 or less, and particularly preferably 5.5 or less. In Al₂O₃/(SnO₂+ZrO₂) When the size is too large, crystal nuclei become large, and the crystallized glass tends to be cloudy.

TiO₂Is a nucleating component for precipitating crystals in the crystallization step. On the other hand, when contained in a large amount, the coloring of the glass is remarkably enhanced and the light transmittance is lowered. In particular containing ZrO₂And TiO₂The zirconium dioxide titanate-based crystal(s) of (a) functions as a crystal nucleus, but undergoes electron transfer (LMCT transfer) from the valence band of oxygen as a ligand to the conduction bands of zirconium dioxide and titanium as central metals, thereby interfering with the coloration of the crystallized glass. In addition, when titanium remains in the residual glass phase, there is a possibility that SiO may be generated₂LM of conduction band of 4-valent titanium from valence band of framework to residual glass phaseAnd (4) CT migration. Furthermore, the residual 3-valent titanium in the glass phase undergoes d-d migration, which interferes with the coloration of the crystallized glass. Further, it is known that ilmenite (FeTiO) occurs in the presence of titanium and iron₃) Coloring the sample; in the case where titanium and tin coexist, the yellow color tends to be increased, and the light transmittance of the ultraviolet region tends to be remarkably reduced. Thus, TiO₂The content of (b) is preferably 0% or more and less than 2%, 0 to 1.95%, 0 to 1.9%, 0 to 1.8%, 0 to 1.7%, 0 to 1.6%, 0 to 1.5%, 0 to 1.4%, 0 to 1.3%, 0 to 1.2%, 0 to 1.1%, 0 to 1.05%, 0 to 1%, 0 to 0.95%, 0 to 0.9%, 0 to 0.85%, 0 to 0.8%, 0 to 0.75%, 0 to 0.7%, 0 to 0.65%, 0 to 0.6%, 0 to 0.55%, 0 to 0.5%, 0 to 0.48%, 0 to 0.46%, 0 to 0.44%, 0 to 0.42%, 0 to 0.4%, 0 to 0.38%, 0 to 0.36%, 0 to 0.34%, 0 to 0.32%, 0 to 0.3%, 0 to 0.28%, 0 to 0.26%, 0.24%, 0.0 to 0.0.24%, 0 to 0.0.38%, 0 to 0.12%, particularly 0 to 0.12%, 0 to 0.12%. However, due to TiO₂Easily incorporated as impurities, e.g. for complete removal of TiO₂The raw material batch becomes expensive, and the manufacturing cost tends to increase. To suppress the increase of the production cost, TiO₂The lower limit of the content of (b) is preferably 0.0003% or more, 0.0005% or more, 0.001% or more, 0.005% or more, 0.01% or more, and particularly preferably 0.02% or more.

TiO₂And ZrO₂Are components that can function as crystal nuclei, respectively. Ti and Zr are elements of the same group, and are similar in electronegativity, ionic radius and the like. Therefore, it is known that oxides tend to have similar molecular conformations in TiO₂And ZrO₂In the presence of (3), phase separation at the initial stage of crystallization is likely to occur. Thus, within the permissible range of coloration, TiO₂/ZrO₂Preferably 0.0001 to 5.0, 0.0001 to 4.0, 0.0001 to 3.0, 0.0001 to 2.5, 0.0001 to 2.0, 0.0001 to 1.5, 0.0001 to 1.0, and particularly preferably 0.0001 to 0.5. TiO 2₂/ZrO₂When the amount is too small, the raw material batch tends to be expensive, and the production cost tends to increase. On the other hand, TiO₂/ZrO₂When the size of the particles is too large,the crystallization nucleation rate becomes slow, and the manufacturing cost may increase.

MgO is solid-dissolved in Li₂O－Al₂O₃－SiO₂Is crystalline, increases Li₂O－Al₂O₃－SiO₂Is a component of the coefficient of thermal expansion of the crystal. The content of MgO is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, more than 0% and not more than 4.9%, 0.1 to 4%, 0.2 to 3%, 0.3 to 2%, 0.4 to 1.5%, 0.5 to 1%, and particularly preferably 0.6 to 0.9%. When the content of MgO is too large, crystals containing Mg are likely to precipitate, and the glass is devitrified, so that the crystallized glass is likely to be broken. Also, the thermal expansion coefficient tends to be too high.

Li₂O－Al₂O₃－SiO₂In the crystallized glass, when a large difference occurs in the thermal expansion coefficient between the crystallized phase after completion of crystallization and the residual glass phase, surface separation, cracking from the inside of the sample, and the like may occur. Li to Li₂O－Al₂O₃－SiO₂When the solid solubility in the system crystal is too high, the volume shrinkage during crystallization becomes large, the thermal expansion coefficient of the crystalline phase after completion of crystallization becomes too low, and a large difference is likely to occur between the thermal expansion coefficients of the crystalline phase and the residual glass phase. As a result, the crystallized glass is likely to be cracked such as surface peeling and cracking. Therefore, MgO/(Li)₂O + MgO) is preferably 0.0001 or more, 0.0005 or more, 0.001 or more, 0.005 or more, 0.01 or more, 0.012 or more, 0.014 or more, 0.016 or more, 0.018 or more, 0.02 or more, 0.022 or more, 0.024 or more, 0.026 or more, 0.028 or more, 0.03 or more, 0.032 or more, 0.034 or more, 0.036 or more, 0.038 or more, 0.04 or more, 0.041 or more, 0.042 or more, 0.043 or more, 0.044 or more, 0.045 or more, particularly 0.046 or more, 0.047 or more, 0.048 or more, 0.049 or more, and particularly preferably 0.05 or more. In addition, MgO/(Li)₂O + MgO) is preferably 0.9 or less.

P₂O₅Is a component that suppresses coarse crystallization and precipitation of devitrification. And is capable of interfering with the formation of crystal nucleiThe component which is likely to undergo phase separation. P₂O₅The content of (b) is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 4.5%, 0 to 4%, 0 to 3.9%, 0 to 3.8%, 0.1 to 3.5%, 0.2 to 3.2%, 0.3 to 2.9%, 0.6 to 2.6%, 0.9 to 2.3%, 1.1 to 2%, 1.2 to 1.7%, and particularly preferably 1.3 to 1.5%. P₂O₅When the content of (A) is excessive, Li₂O－Al₂O₃－SiO₂The amount of crystals deposited is reduced, and the thermal expansion coefficient tends to be high. In addition, P₂O₅If the content of (b) is too large, the raw material batch becomes expensive, and as a result, the production cost becomes high.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass may contain the following components in addition to the above components.

Na₂O is soluble in Li₂O－Al₂O₃－SiO₂The crystallization-related component greatly affects the crystallinity, lowers the viscosity of the glass, and improves the meltability and the moldability of the glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. Na (Na)₂The content of O is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0.1 to 4%, 0.2 to 2%, and particularly preferably 0.3 to 1%. Na (Na)₂When the content of O is too large, crystals containing Na are likely to precipitate to devitrify the glass, and the crystallized glass is likely to be broken. Further, the thermal expansion coefficient tends to be too high.

K₂O is soluble in Li₂O－Al₂O₃－SiO₂The crystallization-related component greatly affects the crystallinity, lowers the viscosity of the glass, and improves the meltability and the moldability of the glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. K₂The content of O is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 3%, 0 to 2%, 0.1 to 1.5%, 0.2 to 1%, and particularly preferably 0.3 to 10%～0.5％。K₂When the content of O is too large, crystals containing K are likely to precipitate to devitrify the glass, and the crystallized glass is likely to be broken. Further, the thermal expansion coefficient tends to be too high.

Li₂O、Na₂O、K₂O is a component that improves the meltability and moldability of the glass, but if the content of these components is too large, the low-temperature viscosity may be excessively lowered, and the glass may excessively flow during crystallization. And, Li₂O、Na₂O、K₂O is a component that may deteriorate weather resistance, water resistance, chemical resistance, and the like of the glass before crystallization. When the glass before crystallization is deteriorated by moisture or the like, a desired crystallization behavior may not be obtained, and desired characteristics may not be obtained. On the other hand, ZrO₂Is a component that functions as a nucleating agent, and has the effect of inhibiting the flow of residual glass by preferentially crystallizing at the initial stage of crystallization. In addition, ZrO₂Efficiently filled with SiO₂The voids of the glass network having a main skeleton have an effect of inhibiting diffusion of protons, various chemical components, and the like in the glass network, and improve the weather resistance, water resistance, chemical resistance, and the like of the glass before crystallization. In order to obtain crystallized glass having a desired shape and properties, it should be appropriately controlled (Li)₂O+Na₂O+K₂O)/ZrO₂。(Li₂O+Na₂O+K₂O)/ZrO₂Preferably 3.0 or less, 2.8 or less, 2.6 or less, 2.5 or less, 2.48 or less, 2.46 or less, and particularly preferably 2.45 or less.

CaO is a component that lowers the viscosity of glass and improves the meltability and moldability of glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. And is also capable of solid solubility in Li₂O－Al₂O₃－SiO₂Is a crystalline component. The preferable content of CaO is 0-10%, 0-9%, 0-8%, 0-7%, 0-6%, 0-5%, 0-4%, 0-3%, 0-2%, 0-1%, and particularly 0-0.5%. When the content of CaO is too large, Ca-containing crystals are likely to precipitate to devitrify the glass, and the crystallized glass is likely to breakAnd (4) loss. Further, the thermal expansion coefficient tends to be too high.

SrO is a component that lowers the viscosity of glass and improves the meltability and moldability of glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. And is also capable of solid solubility in Li₂O－Al₂O₃－SiO₂Is a crystalline component. The content of SrO is preferably 0-10%, 0-9%, 0-8%, 0-7%, 0-6%, 0-5%, 0-4%, 0-3%, 0-2%, 0-1%, and particularly preferably 0-0.5%. When the SrO content is too large, Sr-containing crystals are likely to precipitate to devitrify the glass, and the crystallized glass is likely to be broken. Further, the thermal expansion coefficient tends to be too high.

BaO is a component that lowers the viscosity of the glass and improves the meltability and moldability of the glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. And is also capable of solid solubility in Li₂O－Al₂O₃－SiO₂Is a crystalline component. The content of BaO is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 4%, 0.3 to 3%, 0.6 to 2.5%, 0.9 to 2%, and particularly preferably 1.1 to 1.5%. When the content of BaO is too large, crystals containing Ba are likely to precipitate to devitrify the glass, and the crystallized glass is likely to be broken. Further, the thermal expansion coefficient tends to be too high.

ZnO is a component that lowers the viscosity of glass and improves the meltability and moldability of glass. The component is a component for adjusting the thermal expansion coefficient and refractive index of the crystallized glass. And is also capable of solid solubility in Li₂O－Al₂O₃－SiO₂Is a crystalline component. The content of ZnO is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 4%, 0 to 3%, 0 to 2%, 0 to 1%, and particularly preferably 0 to 0.5%. When the content of ZnO is too large, crystals containing Zn are likely to precipitate to devitrify the glass, and the crystallized glass is likely to be damaged. Further, the thermal expansion coefficient tends to be too high.

B₂O₃Is a component that lowers the viscosity of the glass and improves the meltability and moldability of the glass. Further, the component is a component which can interfere with the ease of phase separation occurring at the time of forming crystal nuclei. B is₂O₃The content of (b) is preferably 0 to 10%, 0 to 9%, 0 to 8%, 0 to 7%, 0 to 6%, 0 to 5%, 0 to 4%, 0 to 3%, 0 to 2%, 0 to 1%, and particularly preferably 0 to 0.5%. B is₂O₃When the content of (b) is too large, the glass is easily devitrified and the crystallized glass is easily broken. And B at the time of melting₂O₃The evaporation amount of (2) increases, and the environmental burden increases. And, B₂O₃If the content of (b) is too large, the raw material batch becomes expensive, and as a result, the production cost becomes high.

CaO、SrO、BaO、ZnO、B₂O₃If these impurities are mixed as impurities and they are completely removed, the raw material batch becomes expensive, and the production cost tends to increase. In order to suppress an increase in production cost without causing any problem in light transmittance, CaO, SrO, BaO, ZnO and B₂O₃The lower limits of the content of (b) are preferably 0.0001% or more, 0.0003% or more, and particularly preferably 0.0005% or more, respectively.

Li₂O－Al₂O₃－SiO₂In the crystallized glass, it is known that phase separation regions are formed in the glass before nucleation and then ZrO is formed in the phase separation regions₂、TiO₂Etc. to form the crystal nuclei. In the formation of phase separation, SnO₂、ZrO₂、TiO₂、P₂O₅、B₂O₃Strong intervention, hence SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃Preferably more than 0% and less than 30%, 0.5-25%, 1-20%, 1.2-17.5%, 1.8-15%, 2-12.5%, 2.1-10%, 2.2-10%, 2.3-9.5%, 2.4-9%, 2.5-8.5%, 2.7-8%, 2.9-7.5%, 3.1-7.5%, 3.2-7.5%, 3.3-7.5%, 3.4-7.5%, SnO₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) Preferably 0.01 or more, 0.015 or more,0.02 or more, 0.025 or more, 0.03 or more, 0.035 or more, 0.04 or more, 0.045 or more, 0.05 or more, 0.055 or more, 0.06 or more, 0.065 or more, 0.07 or more, 0.085 or more, 0.09 or more, 0.095 or more, 0.1 or more, 0.105 or more, 0.11 or more, 0.115 or more, 0.12 or more, 0.125 or more, and particularly preferably 0.13 or more. SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃If too small, a phase separation region is difficult to form, and crystallization becomes difficult. On the other hand, SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃Excess, and/or SnO₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) When the ratio is too small, the phase separation region becomes large, and the crystallized glass tends to be cloudy. Further, SnO₂/(SnO₂+ZrO₂+TiO₂+P₂O₅+B₂O₃) The upper limit of (b) is not particularly limited, but is practically 0.9 or less.

Fe₂O₃Is a component for enhancing the colouring of glass, in particular by reaction with TiO₂、SnO₂The interaction of (a) to (b) significantly enhance the colored component. Fe₂O₃The content of (b) is preferably 0.10% or less, 0.08% or less, 0.06% or less, 0.05% or less, 0.04% or less, 0.035% or less, 0.03% or less, 0.02% or less, 0.015% or less, 0.013% or less, 0.012% or less, 0.011% or less, 0.01% or less, 0.009% or less, 0.008% or less, 0.007% or less, 0.006% or less, 0.005% or less, 0.004% or less, 0.003% or less, and particularly preferably 0.002% or less. However, due to Fe₂O₃Easily incorporated as impurities, e.g. to completely remove Fe₂O₃The raw material batch becomes expensive, and the manufacturing cost tends to increase. To suppress the increase of the production cost, Fe₂O₃The lower limit of the content of (b) is preferably 0.0001% or more, 0.0002% or more, 0.0003% or more, 0.0005% or more, and particularly preferably 0.001% or more.

In the case where titanium and iron coexist, ilmenite (FeTiO) sometimes appears₃) And (3) coloring the sample. Especially in Li₂O－Al₂O₃－SiO₂In the crystallized glass of the present invention, the titanium and iron components which are not precipitated as crystal nuclei or main crystals after crystallization remain in the residual glass, and the occurrence of the above coloring may be promoted. These components can be reduced in design, but because of TiO₂And Fe₂O₃If the impurities are easily mixed as impurities and completely removed, the raw material batch becomes expensive, and the production cost tends to increase. Therefore, in order to suppress the production cost, TiO may be contained in the above range₂And Fe₂O₃In order to reduce the production cost, both components may be contained within an allowable coloring range. In this case, TiO₂/(TiO₂+Fe₂O₃) Preferably 0.001-0.999, 0.001-0.998, 0.001-0.997, 0.001-0.9996, and particularly preferably 0.001-0.995.

In general, the β -spodumene solid solution as the main crystal of the present invention and the β -quartz solid solution as the precursor thereof are composed of SiO₂、Al₂O₃、Li₂O, etc., but the β -spodumene solid solution has a larger void area in the crystals, and alkali metals and alkaline earth metals are easily dissolved in solid solution. Thus, the solid solution of β -spodumene may contain SiO₂、Al₂O₃、Li₂O、Na₂O、K₂O、MgO、CaO、SrO、BaO、ZnO、B₂O₃、P₂O₅Any or all of them. SnO₂、ZrO₂、TiO₂These components are also soluble in a β -spodumene solid solution from the viewpoint of ionic radius, but cause phase separation at the initial stage of crystallization, and are often precipitated as crystal nuclei. Thus, with SiO₂、Al₂O₃And the like, and the probability of solid solution is low, and the possibility of existence in a phase (crystal nucleus, residual glass, etc.) different from the main crystal is high. If the difference in refractive index between the main crystal and the other phase is large, the short-wavelength light is easily refracted, and the desired light transmittance may not be obtained. Thus, (SnO)₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) Preferably 0.03 or more, 0.035 or more, 0.04 or more, 0.045 or more, and particularly preferably 0.05 or more. (SnO)₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) When too large, ZrO is liable to precipitate₂、SnO₂And the like. (SnO)₂+ZrO₂+TiO₂)/(SiO₂+Al₂O₃+Li₂O+Na₂O+K₂O+MgO+CaO+SrO+BaO+ZnO+B₂O₃+P₂O₅) The upper limit of (b) is not particularly limited, and is practically 0.1 or more.

Pt is a component which may be mixed into glass in the form of ions, colloids, metals, or the like, and is colored in yellow to dark brown. This tendency becomes remarkable after crystallization. Further, it has been found through keen examination that when Pt is mixed, nucleation and crystallization behavior of the crystallized glass are affected, and white turbidity is likely to occur in some cases. Therefore, the content of Pt is preferably 7ppm or less, 6ppm or less, 5ppm or less, 4ppm or less, 3ppm or less, 2ppm or less, 1.6ppm or less, 1.4ppm or less, 1.2ppm or less, 1ppm or less, 0.9ppm or less, 0.8ppm or less, 0.7ppm or less, 0.6ppm or less, 0.55ppm or less, 0.5ppm or less, 0.45ppm or less, 0.4ppm or less, 0.35ppm or less, and particularly preferably 0.3ppm or less. Although the incorporation of Pt should be avoided as much as possible, in the case of using a general melting apparatus, it is sometimes necessary to use a Pt material in order to obtain a homogeneous glass. Therefore, if Pt is to be completely removed, the manufacturing cost tends to increase. In order to suppress an increase in production cost without adversely affecting coloring, the lower limit of the content of Pt is preferably 0.0001ppm or more, 0.001ppm or more, 0.005ppm or more, 0.01ppm or more, 0.02ppm or more, 0.03ppm or more, 0.04ppm or more, 0.05ppm or more, 0.06ppm or more, and particularly preferably 0.07ppm or more. In addition, in the case where coloring is allowed to an allowable degree, Pt and ZrO may be added₂、TiO₂And also as a nucleating agent for promoting precipitation of the main crystal. In this case, Pt may be used alone as the nucleating agent, or may be compounded with other components to be used as the nucleating agent. When Pt is used as the nucleating agent, the form thereof is not particularly limited (colloid, metal crystal, and the like).

Rh is a component that may be mixed into glass in the form of ions, colloids, metals, or the like, and is colored in yellow to dark brown like Pt, and tends to make crystallized glass cloudy. Therefore, the Rh content is preferably 7ppm or less, 6ppm or less, 5ppm or less, 4ppm or less, 3ppm or less, 2ppm or less, 1.6ppm or less, 1.4ppm or less, 1.2ppm or less, 1ppm or less, 0.9ppm or less, 0.8ppm or less, 0.7ppm or less, 0.6ppm or less, 0.55ppm or less, 0.5ppm or less, 0.45ppm or less, 0.4ppm or less, 0.35ppm or less, and particularly preferably 0.3ppm or less. Although mixing of Rh should be avoided as much as possible, in the case of using a general melting apparatus, it is sometimes necessary to use an Rh material in order to obtain a homogeneous glass. Therefore, if Rh is to be completely removed, the manufacturing cost tends to increase. In order to suppress an increase in production cost without adversely affecting coloring, the lower limit of the Rh content is preferably 0.0001ppm or more, 0.001ppm or more, 0.005ppm or more, 0.01ppm or more, 0.02ppm or more, 0.03ppm or more, 0.04ppm or more, 0.05ppm or more, 0.06ppm or more, and particularly preferably 0.07ppm or more. In addition, in the case where coloring is allowed to an allowable degree, Rh may be mixed with ZrO₂、TiO₂Likewise as nucleating agents. In this case, Rh may be used alone as the nucleating agent, or may be compounded with other components to serve as the nucleating agent. When Rh is used as a nucleating agent for promoting precipitation of a main crystal, the form thereof is not particularly limited (colloid, metal crystal, and the like).

The Pt + Rh is preferably 9ppm or less, 8ppm or less, 7ppm or less, 6ppm or less, 5ppm or less, 4.75ppm or less, 4.5ppm or less, 4.25ppm or less, 4ppm or less, 3.75ppm or less, 3.5ppm or less, 3.25ppm or less, 3ppm or less, 2.75ppm or less, 2.5ppm or less, 2.25ppm or less, 1.75ppm or less, 1.5ppm or less, 1.25ppm or less, 1ppm or less, 0.95ppm or less, 0.9ppm or less, 0.85ppm or less, 0.8ppm or less, 0.75ppm or less, 0.65ppm or less, 0.6ppm or less, 0.55ppm or less, 0.5ppm or less, 0.45ppm or less, 0.4ppm or less, 0.35ppm or less, and particularly preferably 0.3ppm or less. Although the mixing of Pt and Rh should be avoided as much as possible, in the case of using a general melting apparatus, it is sometimes necessary to use Pt and Rh materials in order to obtain a homogeneous glass. Therefore, if Pt and Rh are to be completely removed, the manufacturing cost tends to increase. In the case where coloring is allowable, the lower limit of Pt + Rh is preferably 0.0001ppm or more, 0.001ppm or more, 0.005ppm or more, 0.01ppm or more, 0.02ppm or more, 0.03ppm or more, 0.04ppm or more, 0.05ppm or more, 0.06ppm or more, and particularly preferably 0.07ppm or more, in order to suppress an increase in production cost.

In developing glass materials, glasses of various compositions are generally produced using various crucibles. Therefore, platinum and rhodium evaporated from the crucible are often present inside the electric furnace for melting. It has been confirmed that Pt and Rh existing in the electric furnace are mixed into the glass, and in order to control the mixing amount of Pt and Rh, not only the raw material and the material of the crucible to be used are selected, but also the melting temperature is lowered and the time is shortened by mounting a quartz lid on the crucible, and thereby the content of Pt and Rh in the glass can be controlled.

As₂O₃、Sb₂O₃Has high toxicity and may pollute the environment in the glass production process, waste glass treatment, and the like. Therefore, Li of the present invention is preferable₂O－Al₂O₃－SiO₂The crystallized glass does not substantially contain these components (specifically, less than 0.1 mass%).

Li of the invention₂O－Al₂O₃－SiO₂In addition to the above components, for example, H may be added to the crystallized glass so long as it does not adversely affect the coloring₂、CO₂、CO、H₂O、He、Ne、Ar、N₂The trace components are contained up to 0.1% respectively. In addition, Ag, Au, Pd, Ir, V, Cr, Sc, Ce, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and,Lu, Ac, Th, Pa, U, etc., tend to increase the raw material cost and the production cost. On the other hand, when glass containing Ag, Au, or the like is irradiated with light and heat-treated, aggregates of these components are formed, and crystallization can be promoted using these as starting points. Pd and the like have various catalytic actions, and specific functions can be imparted to glass or crystallized glass by containing them. In view of these circumstances, when the purpose is to promote crystallization and to provide other functions, the components may be contained in an amount of 1% or less, 0.5% or less, 0.3% or less, and 0.1% or less, respectively, and in addition to the purpose, the components may be contained in an amount of 500ppm or less, 300ppm or less, 100ppm or less, and particularly preferably 10ppm or less.

In addition, Li of the present invention is not particularly limited as long as it does not adversely affect coloring₂O－Al₂O₃－SiO₂In the crystallized glass, SO may be added₃、MnO、Cl₂、Y₂O₃、MoO₃、La₂O₃、WO₃、HfO₂、Ta₂O₅、Nd₂O₃、Nb₂O₅、RfO₂Etc. in a total amount of up to 10%. However, since the raw material ingredients of the above components are expensive and the production cost tends to increase, they may not be added in any particular case. In particular HfO₂High raw material cost of Ta₂O₅Therefore, the total amount of these components is preferably 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, 0.05% or less, less than 0.05%, 0.049% or less, 0.048% or less, 0.047% or less, 0.046% or less, and particularly preferably 0.045% or less.

Li of the present invention having the above-mentioned composition₂O－Al₂O₃－SiO₂The appearance of the crystallized glass is easily colorless.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass is preferably 1% or more and 5% or more at a thickness of 2mm and a wavelength of 360nmMore than 10%, more than 15%, more than 20%, more than 25%, more than 30%, more than 35%, more than 40%, more than 45%, more than 46%, more than 47%, more than 48%, more than 49%, and particularly preferably more than 50%. When the light-transmitting film is used for applications requiring transmission of ultraviolet light, if the transmittance at a wavelength of 360nm is too low, a desired transmission capacity may not be obtained. Particularly, when a YAG laser or the like is used, the transmittance at a wavelength of 360nm is preferably high.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass of the present invention at a thickness of 2mm and a wavelength of 555nm is preferably 10% or more, 15% or more, 20% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 61% or more, 62% or more, 63% or more, 64% or more, 65% or more, 66% or more, 67% or more, 68% or more, 69% or more, and particularly preferably 70% or more. When the light-transmitting film is used for applications requiring transmission of visible light, if the transmittance at a wavelength of 555nm is too low, a desired transmission capacity may not be obtained.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance of the crystallized glass of the present invention at a thickness of 2mm and a wavelength of 1070nm is preferably 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 71% or more, 72% or more, 73% or more, 74% or more, 75% or more, 76% or more, 77% or more, 78% or more, 79% or more, 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, and particularly preferably 85% or more. If the transmittance at a wavelength of 1070nm is too low, it tends to become green.

Li of the invention₂O－Al₂O₃－SiO₂The transmittance change rate of the crystallized glass before and after crystallization at a thickness of 2mm and a wavelength of 360nm is preferably 95% or less, 92.5% or less, 90% or less, 87.5% or less, 85% or less, 82.5% or less, 80% or less, 77.5% or less, 75% or less, 72.5% or less, 70% or less, 68.5% or less, and particularly preferably 68% or less. By reducing the transmittance change rate before and after crystallization, the transmittance after crystallization can be predicted and controlled before crystallization, and desired transmittance can be easily obtained after crystallization. Further, the transmittance change rate before and after crystallization is preferably small not only at a wavelength of 360nm but also in all wavelength regions. Here, "transmittance change rate before and after crystallization" means { (transmittance (%) before crystallization — transmittance (%) after crystallization)/(transmittance (%) before crystallization) } × 100 (%).

Li of the invention₂O－Al₂O₃－SiO₂In the crystallized glass, a β -spodumene solid solution is precipitated as a main crystal, and thus the crystallized glass tends to have a low thermal expansion coefficient.

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 200 ℃ is preferably-20X 10^－7/℃～30×10^－7/℃、－19×10^－7/℃～30×10^－7/℃、－18×10^－7/℃～30×10^－7/℃、－17×10^－7/℃～30×10^－7/℃、－16×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～28×10^－7/℃、－15×10^－7/℃～26×10^－7/℃、－14.5×10^－7/℃～25×10^－7/℃、－13.5×10^－7/℃～25×10^－7/℃、－12.5×10^－7/℃～25×10^－7/℃、－11.5×10^－7/℃～25×10^－7/℃、－10.5×10^－7/℃～25×10^－7/℃、－10×10^－7/℃～24.5×10^－7/℃、－10×10^－7/℃～23.5×10^－7/℃、－10×10^－7/℃～22.5×10^－7/℃、－10×10^－7/℃～21.5×10^－7/℃、－10×10^－7/℃～20.5×10^－7/℃、－9.5×10^－7/℃～20×10^－7/℃、－9×10^－7/℃～19.5×10^－7/℃、－8.5×10^－7/℃～19×10^－7/℃、－8×10^－7/℃～18.5×10^－7/℃、－7.5×10^－7/℃～18×10^－7/℃、－7×10^－7/℃～17.5×10^－7/℃、－6.5×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～16.5×10^－7/℃、－6×10^－7/℃～16×10^－7/℃、－5.5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～15.5×10^－7Per DEG C, particularly preferably-5X 10^－7/℃～15×10^－7V. C. Too low or too high thermal expansion coefficient at 20-200 ℃ can easily change the size of the processed substrate.

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 380 ℃ is preferably-20 x 10^－7/℃～30×10^－7/℃、－19×10^－7/℃～30×10^－7/℃、－18×10^－7/℃～30×10^－7/℃、－17×10^－7/℃～30×10^－7/℃、－16×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～28×10^－7/℃、－15×10^－7/℃～26×10^－7/℃、－14.5×10^－7/℃～25×10^－7/℃、－13.5×10^－7/℃～25×10^－7/℃、－12.5×10^－7/℃～25×10^－7/℃、－11.5×10^－7/℃～25×10^－7/℃、－10.5×10^－7/℃～25×10^－7/℃、－10×10^－7/℃～24.5×10^－7/℃、－10×10^－7/℃～23.5×10^－7/℃、－10×10^－7/℃～22.5×10^－7/℃、－10×10^－7/℃～21.5×10^－7/℃、－10×10^－7/℃～20.5×10^－7/℃、－9.5×10^－7/℃～20×10^－7/℃、－9×10^－7/℃～19.5×10^－7/℃、－8.5×10^－7/℃～19×10^－7/℃、－8×10^－7/℃～18.5×10^－7/℃、－7.5×10^－7/℃～18×10^－7/℃、－7×10^－7/℃～17.5×10^－7/℃、－6.5×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～16.5×10^－7/℃、－6×10^－7/℃～16×10^－7/℃、－5.5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～15.5×10^－7Per DEG C, particularly preferably-5X 10^－7/℃～15×10^－7V. C. Too low or too high thermal expansion coefficient at 20-380 ℃ can easily change the size of the processed substrate.

Li of the invention₂O－Al₂O₃－SiO₂The thermal expansion coefficient of the crystallized glass at 20 to 750 ℃ is preferably-20X 10^－7/℃～30×10^－7/℃、－19×10^－7/℃～30×10^－7/℃、－18×10^－7/℃～30×10^－7/℃、－17×10^－7/℃～30×10^－7/℃、－16×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～30×10^－7/℃、－15×10^－7/℃～28×10^－7/℃、－15×10^－7/℃～26×10^－7/℃、－14.5×10^－7/℃～25×10^－7/℃、－13.5×10^－7/℃～25×10^－7/℃、－12.5×10^－7/℃～25×10^－7/℃、－11.5×10^－7/℃～25×10^－7/℃、－10.5×10^－7/℃～25×10^－7/℃、－10×10^－7/℃～24.5×10^－7/℃、－10×10^－7/℃～23.5×10^－7/℃、－10×10^－7/℃～22.5×10^－7/℃、－10×10^－7/℃～21.5×10^－7/℃、－10×10^－7/℃～20.5×10^－7/℃、－9.5×10^－7/℃～20×10^－7/℃、－9×10^－7/℃～19.5×10^－7/℃、－8.5×10^－7/℃～19×10^－7/℃、－8×10^－7/℃～18.5×10^－7/℃、－7.5×10^－7/℃～18×10^－7/℃、－7×10^－7/℃～17.5×10^－7/℃、－6.5×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～17×10^－7/℃、－6×10^－7/℃～16.5×10^－7/℃、－6×10^－7/℃～16×10^－7/℃、－5.5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～16×10^－7/℃、－5×10^－7/℃～15.5×10^－7Per DEG C, particularly preferably-5X 10^－7/℃～15×10^－7V. C. Too low or too high thermal expansion coefficient at 20-750 ℃ can easily cause the dimensional change of the processed substrate to be large.

Li of the invention₂O－Al₂O₃－SiO₂The Young's modulus of the crystallized glass is preferably 60 to 120GPa, 70 to 110GPa, 75 to 105GPa, 80 to 105GPa, and particularly preferably 80 to 100 GPa. When the Young's modulus is too low or too high, the crystallized glass is easily broken.

Li of the invention₂O－Al₂O₃－SiO₂The rigidity modulus of the crystallized glass is preferably 25 to 50GPa, 27 to 48GPa, 29 to 46GPa, and particularly preferably 30 to 45 GPa. Too low or too high a modulus of rigidity makes the crystallized glass easily broken.

Li of the invention₂O－Al₂O₃－SiO₂The poisson's ratio of the crystallized glass is preferably 0.35 or less, 0.32 or less, 0.3 or less, 0.28 or less, 0.26 or less, and particularly preferably 0.25 or less. If the poisson's ratio is too large, the crystallized glass is easily broken.

Next, production of Li of the present invention is described₂O－Al₂O₃－SiO₂A method of crystallizing a glass will be described.

First, a raw material batch prepared so as to be glass having the above composition is put into a glass melting furnace, melted at 1500 to 1750 ℃, and then molded. In addition, a flame melting method using a burner or the like, an electric melting method using electric heating, or the like can be used for melting glass. Further, the melting by laser irradiation or the melting by plasma may be used. The shape of the sample is not particularly limited, and may be plate-like, fiber-like, film-like, powder-like, spherical, hollow, or the like.

Then, the obtained crystallizable glass (glass capable of being crystallized) is subjected to a heat treatment to be crystallized. Specifically, the crystal is grown by heat treatment under the conditions of 700 to 950 ℃ (preferably 750 to 900 ℃) for 0.1 to 100 hours (preferably 1 to 60 hours) to nucleate the crystal, then under the conditions of 800 to 1050 ℃ (preferably 800 to 1000 ℃) for 0.1 to 50 hours (preferably 0.2 to 10 hours) to heat treat the crystal, and then under the conditions of 900 to 1200 ℃ (preferably 950 to 1100 ℃) for 0.1 to 50 hours (preferably 0.1 to 10 hours). Thus, colorless Li in which β -spodumene solid solution crystals are precipitated as main crystals can be obtained₂O－Al₂O₃－SiO₂A crystallized glass.

Further, the crystallization may be promoted by applying or irradiating an acoustic wave or an electromagnetic wave. The cooling rate of the crystallized glass reaching a high temperature may be a certain specific temperature gradient, or may be a cooling rate of two or more levels. When it is desired to obtain sufficient thermal shock resistance, it is desirable to control the cooling rate so that the structure of the residual glass phase is sufficiently relaxed. The average cooling rate from 800 ℃ to 25 ℃ is preferably 3000 ℃/min, 1000 ℃/min or less, 500 ℃/min or less, 400 ℃/min or less, 300 ℃/min or less, 200 ℃/min or less, 100 ℃/min or less, 50 ℃/min or less, 25 ℃/min or less, 10 ℃/min or less, and particularly preferably 5 ℃/min or less, in the portion inside the thick wall farthest from the surface of the crystallized glass. When long-term dimensional stability is to be obtained, it is more preferably 2.5 ℃/min or less, 1 ℃/min or less, 0.5 ℃/min or less, 0.1 ℃/min or less, 0.05 ℃/min or less, 0.01 ℃/min or less, 0.005 ℃/min or less, 0.001 ℃/min or less, 0.0005 ℃/min or less, and particularly preferably 0.0001 ℃/min or less. In addition to the case of performing physical strengthening treatment by air cooling, water cooling, or the like, it is preferable that the cooling rate of the crystallized glass is close to the cooling rate of the surface to the thick inner portion farthest from the surface. The value obtained by dividing the cooling rate of the inner part of the thick wall farthest from the surface by the cooling rate of the surface is preferably 0.0001 to 1, 0.001 to 1, 0.01 to 1, 0.1 to 1, 0.5 to 1, 0.8 to 1, 0.9 to 1, and particularly preferably 1. By making it close to 1, residual strain is less likely to occur at all positions of the crystallized glass sample, and long-term dimensional stability is easily obtained. The cooling rate of the surface can be estimated by a contact thermometer or a radiation thermometer, and the internal temperature can be estimated from the numerical data, the specific heat of the crystallized glass and the cooling medium, the thermal conductivity, and the like by measuring the heat quantity and the rate of change in the heat quantity of the cooling medium by placing the crystallized glass in a high-temperature state in the cooling medium.

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass may be chemically strengthened. The treatment conditions for the chemical strengthening treatment may be appropriately selected in consideration of the glass composition, the crystallinity, the type of molten salt, and the like, and the treatment time and the treatment temperature may be selected as appropriate. For example, in order to easily perform chemical strengthening after crystallization, a large amount of Na contained in the residual glass can be selected₂The glass composition of O may also intentionally reduce the crystallinity. The molten salt may contain an alkali metal such as Li, Na, or K, or may contain a plurality of kinds. Further, not only the usual one-stage strengthening but also the multi-stage chemical strengthening may be selected. In addition, Li of the present invention is subjected to chemical strengthening or the like before crystallization₂O－Al₂O₃－SiO₂The sample can be reduced as compared with the inside of the sample by treating the crystallized glassLi of surface₂And (4) the content of O. By crystallizing such a glass, the crystallinity of the sample surface is lower than that of the interior of the sample, and the coefficient of thermal expansion of the sample surface is relatively high, whereby compressive stress due to the difference in thermal expansion can be introduced into the sample surface. When the crystallinity of the sample surface is low, the glass phase change is large on the surface, and the chemical resistance and gas barrier property can be improved by selecting the glass composition.

Examples

The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. Tables 1 to 4 show examples (sample Nos. 1 to 5, 7 to 25) and comparative example (sample No.6) of the present invention.

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

First, each raw material was blended in the form of oxide, hydroxide, carbonate, nitrate, etc. to obtain a glass batch having the composition described in tables 1 to 4. Putting the obtained glass batch into a crucible containing platinum and rhodium, a reinforced platinum crucible containing no rhodium, a refractory crucible or a quartz crucible, melting for 4-100 hours at 1600 ℃, heating to 1650-1680 ℃, melting for 0.5-20 hours, rolling to form the glass batch into a thickness of 5mm, performing heat treatment at 700 ℃ for 30 minutes by using an annealing furnace, and cooling the annealing furnace to room temperature at 100 ℃/h to obtain the crystalline glass. The melting is performed by an electric melting method widely used in the development of glass materials.

Further, it was confirmed that the glass composition of sample No.15 was capable of melting glass by burner heating, electric heating, laser irradiation, or the like, and thereafter it was also confirmed that the glass sample could be molded into a hemispherical shape, a spherical shape, a fibrous shape, a powdery shape, a thin plate shape, a tubular shape, or a valve shape by a pressing method, a redraw method, a spraying method, a roll method, a film method, an overflow (fusion) method, a blowing method, or the like. Further, it was confirmed that the glass composition of sample No.16 was solidified into a plate shape by pouring a molten glass on a liquid having a higher specific gravity than that of sample No.16 and then cooling the liquid. In addition, regardless of the glass produced by any of the methods, crystallization was successfully carried out under the conditions shown in the table.

The Pt and Rh contents of the prepared samples were analyzed by an ICP-MS apparatus (Agilent 8800, manufactured by AGILEINT TECHNOLOGY). First, the prepared glass sample is pulverized, moistened with pure water, and then dissolved by adding perchloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and the like. Thereafter, the Pt and Rh contents of the samples were measured by ICP-MS. The Pt and Rh contents of the respective measurement samples were determined based on calibration curves prepared in advance using Pt and Rh solutions having known concentrations. The measurement mode is Pt: he gas/HMI (low mode), Rh: he gas/HMI (medium mode), mass number using Pt: 198. rh: 103. and, Li of sample was prepared₂The O content was analyzed by an atomic absorption spectrometer (ContrA 600, manufactured by ANALYTIK JENA). The procedure of dissolution of the glass sample, the use of calibration curves, and the like are basically the same as those of the Pt and Rh analyses. Other components may be blended with Pt, Rh or Li₂O is similarly measured by ICP-MS or atomic absorption spectrometry, or a glass sample of known concentration previously examined by ICP-MS or atomic absorption spectrometry is used as a sample for calibration curve, a calibration curve is prepared by XRF analyzer (ZSX PrimusIV, manufactured by RIGAKU), and then the actual XRF analysis value of each component is determined from the calibration curveThe content of (a). In XRF analysis, tube voltage, tube current, exposure time, etc. are adjusted at any time according to the analysis components.

The produced glass was subjected to nucleation under the heat treatment conditions shown in the table, and then to crystallization by crystal growth. The obtained crystallized glass was evaluated for transmittance, precipitated crystal, thermal expansion coefficient, young's modulus, rigidity modulus, poisson's ratio, fracture, and color tone.

Regarding the transmittance, the transmittance at each wavelength was measured and evaluated by a spectrophotometer with respect to a crystallized glass plate optically polished on both sides to a thickness of 2 mm. A Nissan spectrophotometer V-670 was used for the measurement. Also, an integrating sphere unit "ISN-723" is attached to V-670. The measurement wavelength region is 200 to 1500nm, the scanning speed is 200 nm/min, the sampling interval is 1nm, the wavelength region with the bandwidth of 200 to 800nm is 5nm, and the wavelength region other than the wavelength region is 20 nm. Baseline correction (for 100%) and dark assay (for 0%) were performed prior to assay. In the dark measurement, the barium sulfate plate with ISN-723 was removed.

The precipitated crystals were evaluated by an X-ray diffractometer (Smart Lab, fully automatic multipurpose X-ray diffractometer manufactured by RIGAKU). The scanning mode is 2 theta/theta measurement, the scanning type is continuous scanning, the width of a scattering and diverging slit is 1 degree, the width of a light receiving slit is 0.2 degree, the measurement range is 10-60 degrees, the measurement step is 0.1 degree, and the scanning speed is 5 degrees/minute. As the precipitation seed crystal identified at this time, a β -spodumene solid solution is shown as "β -S" in the table.

Coefficient of thermal expansion is processed intoThe crystallized glass sample of (2) is evaluated by the average linear thermal expansion coefficient measured at a temperature range of 20 to 200 ℃, 20 to 380 ℃ and 20 to 750 ℃. A Dilator manufactured by NETZSCH was used for the measurement.

Regarding Young's modulus, rigidity modulus and Poisson's ratio, a plate-like sample (40 mm. times.20 mm. times.2 mm) whose surface was polished using a polishing liquid in which No. 1200 alumina powder was dispersed was measured at room temperature using a free resonance elastic modulus measuring apparatus (JE-RT 3, manufactured by TECHNNO-PLUS, Japan).

Regarding the breakage, the breakage of the crystallized glass was visually observed and evaluated as "o", and the breakage was observed and evaluated as "x".

Regarding the color tone, the crystallized glass was evaluated as colorless when visually observed as "o", and the glass was evaluated as "x" when not colorless.

As is clear from tables 1 to 4, in the crystallized glasses of samples No.1 to 5 and 7 to 25, a β -spodumene solid solution was precipitated as a main crystal, and the transmittance in the ultraviolet to infrared regions was high and the thermal expansion coefficient was low. Further, no cracking was observed, and the color was colorless. The crystallized glass of No.6 as a comparative example had a yellow appearance and a low transmittance in the ultraviolet region.

As is clear from Table 2, Li of the present invention₂O－Al₂O₃－SiO₂The crystallized glass can be crystallized in a short time, and a high transmittance can be obtained. The crystallization conditions may be changed in accordance with the required characteristics, but the crystallization conditions are comparable to those of currently used Li₂O－Al₂O₃－SiO₂Since the process speed of the crystallized glass is high, the crystallized glass can be produced at low cost by using conventional equipment.

Industrial applicability

Li of the invention₂O－Al₂O₃－SiO₂The crystallized glass has high transparency in the ultraviolet to infrared region and low thermal expansion, and is therefore particularly suitable for use as a substrate for a semiconductor. Further, the composition is suitably used for front windows of petroleum furnaces, diesel stoves, and the like, substrates for high-tech products such as color filters, substrates for image sensors, and the like, electronic component firing jigs, light diffusion plates, core tubes for semiconductor manufacture, masks for semiconductor manufacture, optical lenses, dimension measuring members, communication members, building members, chemical reaction containers, top plates for electromagnetic cooking, heat-resistant tableware, heat-resistant covers, window glasses for fire doors, members for astronomical telescopes, members for space optics, and the like.