WO2016017435A1 - Crystallized glass - Google Patents

Abstract

Provided is a crystallized glass that makes it possible to minimize changes in size even when heat treatment is performed at a temperature that is equal to or less than the glass transition point temperature thereof and the crystallized glass is subsequently left in an environment in which the temperature is liable to change. This crystallized glass is characterized in that: the difference (Δα) in the thermal expansion coefficient before and after heat treatment is within 0±0.20×10^-7/°C when heat treatment is performed for 24 hours at a temperature from 300 °C to the glass transition point temperature; and the thermal expansion coefficient at -40 to 80 °C after the heat treatment is within 0±0.3×10^-7/°C.

Description

Crystallized glass

The present invention relates to crystallized glass.

A resonator using optical interference functions as a narrow-band wavelength filter and is used in many devices in a wavelength division multiplexing optical communication system. Among them, the etalon is an important resonator used for a wavelength locker for stabilizing the wavelength of a semiconductor laser, a gain equalizer for an optical signal, and the like. An etalon is composed of a pair of parallel flat half mirrors with high flatness and parallelism, and light incident on the etalon undergoes multiple interference between the half mirrors so that light of a wavelength corresponding to the interference order is periodically generated. It has the property of transmitting.

The space between the half mirror and the half mirror is called a cavity. In the cavity, it is required that the transmission wavelength does not change due to a temperature change during use. Specifically, it is required that the refractive index and the interval between the half mirrors do not change even if the temperature changes so that the optical path length does not change due to the temperature change.

Therefore, the cavity is filled with air with a very small change in refractive index with respect to temperature. When the cavity is filled with air, a spacer is arranged between the half mirrors to form an air gap.

Also, in order to prevent the distance between the half mirrors from changing even when the temperature changes, crystallized glass having a small thermal expansion coefficient as shown in Patent Document 1 is used as the spacer.

When the spacer and the half mirror are joined, they are joined by an optical contact method that eliminates the use of an adhesive that causes a large change in the interval between the half mirrors due to a temperature change during use. In the optical contact method, in order to increase the bonding strength between the spacer and the half mirror in a short time, the spacer and the half mirror are brought into contact with each other and then heated to a temperature equal to or lower than the glass transition point.
JP 2004-29723 A

However, when the spacer and the half mirror are joined while heating, the spacer dimensions do not change due to the heat treatment at the time of joining, but the spacer dimensions change due to temperature changes during use after the heat treatment. There is a problem in that the distance between each other cannot be kept constant and desired optical characteristics cannot be obtained.

An object of the present invention is to provide a crystallized glass capable of suppressing a dimensional change even if it is subjected to a heat treatment at a temperature below the glass transition point and then exposed to an environment in which the temperature changes. .

That is, the crystallized glass of the present invention is heat-treated at a temperature of 300 ° C. to the glass transition point for 24 hours, and the difference in thermal expansion coefficient (Δα) before and after the heat treatment is within ± 0.20 × 10 ⁻⁷ / ° C. The thermal expansion coefficient at −40 to 80 ° C. after the heat treatment is within 0 ± 0.3 × 10 ⁻⁷ / ° C.

The crystallized glass of the present invention can be subjected to heat treatment at a temperature not higher than the glass transition point, and thereafter, even if it is exposed to an environment where the temperature changes, dimensional change due to temperature change can be suppressed. Therefore, in particular, it can be suitably used as a spacer for etalon that requires dimensional stability due to temperature change.

The crystallized glass of the present invention is heat-treated at a temperature of 300 ° C. to the glass transition point for 24 hours, and the difference in thermal expansion coefficient (Δα) before and after the heat treatment is within ± 0.20 × 10 ⁻⁷ / ° C., that is, −0 by reducing the ^{.20 × 10 -7 /℃~+0.20×10 -7 / ℃} , suppressing a change in the thermal expansion coefficient of the crystallized glass by heat treatment, while suppressing the dimensional change of the crystallized glass, after heat treatment the thermal expansion coefficient of -40 ~ 80 ℃ 0 ± 0.3 × 10 -7 / ℃ within, ie with ^{-0.3 × 10 -7 /℃~+0.3×10 -7 / ℃} , The change of the thermal expansion coefficient of the crystallized glass due to temperature change is suppressed, and the dimensional change of the crystallized glass is suppressed. Therefore, even if it heat-processes at the temperature below a glass transition point, and exposes to the environment where temperature changes after that, crystallized glass with a small dimensional change can be obtained. A preferred range of the difference in thermal expansion coefficient ([Delta] [alpha]) before and after the heat treatment within ± 0.15 × ^{10 -7} / ℃, i.e. be a -0.15 × ^{10 -7} /℃~+0.15×10 ^-7 / ℃ The preferable range of the coefficient of thermal expansion at −40 to 80 ° C. after the heat treatment is within 0 ± 0.25 × 10 ⁻⁷ / ° C., that is, −0.25 × 10 ⁻⁷ / ° C. to + 0.25 × 10 ⁻⁷ / ° C.

In order to reduce the difference (Δα) in the thermal expansion coefficient before and after the heat treatment and to make the thermal expansion coefficient at −40 to 80 ° C. after the heat treatment within 0 ± 0.3 × 10 ⁻⁷ / ° C., the crystal In the vitrified glass, the kind of crystal to be precipitated, the degree of crystallinity (ratio of crystals to be precipitated), the composition of crystals, the ratio of glass phase, the composition of glass phase, and the like may be adjusted.

Specifically, β-quartz solid solution or β-eucryptite solid solution is preferably precipitated as the type of main crystal, and the crystallinity is preferably a crystallized glass having a mass percentage of 72 to 80%. . A more preferable range of crystallinity is 73 to 79% by mass percentage. By precipitating a β-quartz solid solution or β-eucryptite solid solution having a negative thermal expansion coefficient as the main crystal and setting the crystallinity to 73 to 79% by mass percentage, the negative thermal expansion coefficient of the crystal phase The positive thermal expansion coefficient of the glass phase is offset and the thermal expansion coefficient of the crystallized glass can be brought close to 0 × 10 ⁻⁷ / ° C. (zero), making it easy to obtain crystallized glass with small dimensional change due to temperature change. Become. Further, in the crystallized glass, since the proportion of the glass phase that undergoes a structural change by heat treatment can be reduced, a change in the coefficient of thermal expansion due to the heat treatment can be suppressed, and a crystallized glass having a small dimensional change by the heat treatment can be easily obtained. If the degree of crystallinity is too low, the thermal expansion coefficient of the crystal phase tends to increase in the negative direction, and the SiO ₂ content of the glass phase increases and the thermal expansion coefficient of the glass phase decreases. Tend to. Therefore, the negative thermal expansion coefficient of the crystal phase and the positive thermal expansion coefficient of the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the negative direction, and the dimensional change due to temperature change increases. Cheap. On the other hand, if the degree of crystallinity becomes too high, the thermal expansion coefficient of the crystallized glass tends to change from negative to positive, and the content of SiO ₂ in the glass phase decreases and the thermal expansion of the glass phase. The coefficient tends to increase. Therefore, the thermal expansion coefficient of the crystal phase and the thermal expansion coefficient of the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction, and the dimensional change due to temperature change tends to increase.

In the crystallized glass of the present invention, the solid solubility n of SiO ₂ in the β-quartz solid solution or β-eucryptite solid solution represented by Li ₂ O · Al ₂ O ₃ · nSiO ₂ is 6.9 in molar ratio. The above is preferable. By setting the solid solubility n to a molar ratio of 6.9 or more, the thermal expansion coefficient of the β-quartz solid solution or β-eucryptite solid solution is prevented from becoming too large in the negative direction, so that the temperature after the heat treatment is -40 to The thermal expansion coefficient of crystallized glass at 80 ° C. can be brought close to 0 × 10 ⁻⁷ / ° C. (zero). When the solid solubility n is too small, the thermal expansion coefficient of β-quartz solid solution or β-eucryptite solid solution tends to be too large in the negative direction, and the difference in thermal expansion coefficient before and after heat treatment (Δα) is reduced. However, the thermal expansion coefficient of the crystallized glass is hardly brought close to 0 × 10 ⁻⁷ / ° C., and it becomes difficult to obtain a crystallized glass having a small dimensional change due to a temperature change. A more preferable range of the solid solubility n is 7.0 or more in terms of molar ratio.

In the crystallized glass of the present invention, the thermal expansion coefficient of the crystal phase at 20 to 300 ° C. is preferably −11 × 10 ⁻⁷ to 0 × 10 ⁻⁷ / ° C. If the thermal expansion coefficient of the crystalline phase becomes too large in the negative direction, the heat of the crystallized glass at −40 to 80 ° C. after the heat treatment while reducing the difference (Δα) in the thermal expansion coefficient before and after the heat treatment. It becomes difficult to bring the expansion coefficient close to 0 × 10 ⁻⁷ / ° C., and it becomes difficult to obtain a crystallized glass having a small dimensional change due to a temperature change. A more preferable range of the thermal expansion coefficient of the crystal phase is −10.5 × 10 ⁻⁷ to 0 × 10 ⁻⁷ / ° C.

In the crystallized glass of the present invention, the crystal phase is SiO ₂ 65.0 to 80.0%, Al ₂ O ₃ 10.0 to 18.0%, Li ₂ O 3.0 to 6 in mass percentage. 0.0%, MgO 0-2.0%, ZnO 0-2.0%, TiO ₂ 0.5-4.0%, ZrO ₂ 0.5-4.0%, P ₂ O ₅ 0-0. It is preferable to contain 5%. If the crystal phase has such a composition, β-quartz solid solution or β-eucryptite solid solution is precipitated as the main crystal, and crystallinity, solid solubility n, and thermal expansion of the crystal Since the coefficient tends to be in the above range, it becomes easy to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. The reason for determining the composition range of the crystal phase as described above is as follows.

SiO ₂ is a component constituting a crystal in the crystal phase, and its content is 65.0 to 80.0%. When the content of SiO ₂ increases, the thermal expansion coefficient of the crystal phase tends to change from negative to positive, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass is increased. It tends to increase in the positive direction, and it becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. On the other hand, when the content decreases, the solid solubility n of SiO ₂ in the β-quartz solid solution or β-eucryptite solid solution represented by Li ₂ O.Al ₂ O ₃ .nSiO ₂ tends to decrease, and the heat of the crystal phase The coefficient of expansion tends to be too large in the negative direction, and the coefficient of thermal expansion of the crystallized glass at -40 to 80 ° C after the heat treatment while reducing the difference (Δα) in the thermal expansion coefficient before and after the heat treatment Is difficult to approach 0 × 10 ⁻⁷ / ° C., and it becomes difficult to obtain crystallized glass with small dimensional change due to temperature change. A more preferable range of SiO ₂ is 70.0 to 78.0%.

Al ₂ O ₃ is a component constituting the crystal in the crystal phase, and its content is 10.0 to 18.0%. When the content of Al ₂ O ₃ increases, the solid solubility n of SiO _{2 in} the crystal tends to decrease, and the thermal expansion coefficient of the crystal phase tends to become too large in the negative direction. A crystal whose thermal expansion coefficient of crystallized glass at −40 to 80 ° C. after heat treatment cannot be brought close to 0 × 10 ⁻⁷ / ° C. while reducing the difference (Δα), and whose dimensional change due to temperature change is small. It becomes difficult to obtain a vitrified glass. On the other hand, when the content decreases, the thermal expansion coefficient of the crystal phase tends to increase, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of Al ₂ O ₃ is 13.0 to 18.0%.

Li ₂ O is a component constituting a crystal in the crystal phase, and its content is 3.0 to 6.0%. When the content of Li ₂ O increases, the solid solubility n of SiO _{2 in} the crystal tends to decrease, and the thermal expansion coefficient of the crystal phase tends to become too large in the negative direction. While reducing (Δα), the thermal expansion coefficient of the crystallized glass at −40 to 80 ° C. after heat treatment becomes difficult to approach 0 × 10 ⁻⁷ / ° C., and the crystallization is small in dimensional change due to temperature change. It becomes difficult to obtain glass. On the other hand, when the content decreases, the thermal expansion coefficient of the crystal phase tends to increase, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of Li ₂ O is 3.0 to 5.5%.

MgO and ZnO are components that dissolve in the crystal in the crystal phase, and the content of these components is 0 to 2.0%, respectively. When the content of these components is increased, in addition to β-quartz solid solution or β-eucryptite solid solution, dissimilar crystals such as spinel and garnite are likely to precipitate, and the thermal expansion coefficient of the crystal phase increases, Crystallized glass may be damaged by temperature change during use. More preferable ranges of MgO and ZnO are 0 to 1.5%, respectively.

TiO ₂ and ZrO ₂ are crystal nucleus components in the crystal phase, and the contents of these components are 0.5 to 4.0%, respectively. When the content of these components is increased, different types of crystals are likely to be precipitated, the thermal expansion coefficient of the crystal phase may be increased, and the crystallized glass may be damaged by heat treatment or temperature changes during use. On the other hand, when the content of these components is reduced, it becomes difficult to obtain a desired crystallinity, nucleation becomes insufficient, crystals having a desired particle diameter cannot be obtained, and β- Quartz solid solution or β-eucryptite solid solution easily transitions to β-spodumene solid solution having a positive coefficient of thermal expansion at low temperature. As a result, the thermal expansion coefficient of crystallized glass is 0 × 10 ⁻⁷ / ° C. (zero). It is difficult to obtain crystallized glass with small dimensional change due to temperature change. More preferable ranges of TiO ₂ and ZrO ₂ are 0.5 to 3.5%, respectively.

P ₂ O ₅ is a component that can be a crystal nucleus in the crystal phase, and its content is 0 to 0.5%. When the content of P ₂ O ₅ is increased, different types of crystals are likely to be precipitated, the thermal expansion coefficient of the crystal phase may be increased, and the crystallized glass may be damaged due to heat treatment or temperature changes during use. A more preferable range of P ₂ O ₅ is 0 to 0.4%.

In the crystallized glass of the present invention, the glass phase has a mass percentage of SiO ₂ 30.0 to 50.0%, Al ₂ O ₃ 31.0 to 45.0%, Li ₂ O 1.0 to 3 0.0%, MgO 0-1.0%, ZnO 0-1.0%, TiO ₂ 0-5.0%, ZrO ₂ 0-5.0%, P ₂ O ₅ 0-9.0%, BaO It preferably contains 0 to 8.0%, Na ₂ O 0 to 4.0%, and K ₂ O 0 to 4.0%. If the glass phase has such a composition, the structural change of the glass phase due to the heat treatment hardly occurs, and it becomes easy to obtain crystallized glass with a small dimensional change due to the heat treatment. The reason for determining the composition range of the glass phase as described above is as follows.

SiO ₂ is a component that forms a glass skeleton in the glass phase, and its content is 30.0 to 50.0%. When the content of SiO ₂ increases, the thermal expansion coefficient of the glass phase tends to decrease, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the negative direction. In addition, it is difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. On the other hand, when the content decreases, the thermal expansion coefficient of the glass phase tends to increase, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases in the positive direction. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of SiO ₂ is 32.0 to 48.0%.

Like SiO ₂ , Al ₂ O ₃ is a component that forms a glass skeleton in the glass phase, and its content is 31.0 to 45.0%. When the content of Al ₂ O ₃ increases, the thermal expansion coefficient of the glass phase tends to decrease, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass increases in the negative direction. There is a tendency, and it becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. On the other hand, when the content decreases, the thermal expansion coefficient of the glass phase tends to increase, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases in the positive direction. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of Al ₂ O ₃ is 32.0 to 42.0%.

Li ₂ O is a glass modifying component in the glass phase, and its content is 1.0 to 3.0. When the Li ₂ O content increases, the thermal expansion coefficient of the glass phase tends to increase, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass has a positive direction. It is difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. On the other hand, when the content is reduced, the thermal expansion coefficient of the glass phase tends to be small, the thermal expansion coefficients of the crystal phase and the glass phase are not offset, and the thermal expansion coefficient of the crystallized glass tends to increase in the negative direction. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of Li ₂ O is 1.5 to 3.0%.

MgO and ZnO are glass modifying components in the glass phase, and the content of these components is 0 to 1.0%, respectively. When the content of these components increases, the thermal expansion coefficient of the glass phase tends to increase, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases in the positive direction. It tends to be large, and it becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. Moreover, it becomes easy to devitrify and it becomes difficult to obtain homogeneous glass. More preferable ranges of MgO and ZnO are 0 to 0.8%, respectively.

TiO ₂ and ZrO ₂ are glass modifying components in the glass phase, and the content of these components is 0 to 5.0%, respectively. When the content of these components increases, devitrification easily occurs and it becomes difficult to obtain a homogeneous glass. More preferable ranges of TiO ₂ and ZrO ₂ are 0 to 4.0%, respectively.

P ₂ O ₅ is a component that forms a glass skeleton in the glass phase, and its content is 0 to 9.0%. When the content of P ₂ O ₅ increases, the thermal expansion coefficient of the crystallized glass tends to increase significantly in the positive direction, and it becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. Moreover, it becomes easy to devitrify and it becomes difficult to obtain homogeneous glass. A more preferable range of P ₂ O ₅ is 0 to 7.0%.

BaO is a glass modifying component in the glass phase, and its content is 0 to 8.0%. When the content of BaO increases, the thermal expansion coefficient of the crystallized glass tends to increase significantly in the positive direction, and it becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. Moreover, it becomes easy to devitrify and it becomes difficult to obtain homogeneous glass. A more preferable range of BaO is 0 to 7.0%.

Na ₂ O and K ₂ O are glass modifying components in the glass phase, and the content of these components is 0 to 4.0%, respectively. When the content of these components increases, the thermal expansion coefficient of the glass phase increases in the positive direction, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. More preferable ranges of Na ₂ O and K ₂ O are 0 to 3.0%, respectively.

Further, the crystallized glass of the present invention is, by mass percentage, SiO ₂ 55.0-70.0%, Al ₂ O ₃ 15.0-30.0%, Li ₂ O 2.0-6.0%, MgO 0-2.0%, ZnO 0-2.0%, TiO ₂ 0-4.0%, ZrO ₂ 0-4.0%, P ₂ O ₅ 0-4.0%, BaO 0-2. It preferably has a composition of 0%, Na ₂ O 0-4.0%, K ₂ O 0-4.0%. If the crystallized glass has such a composition, it becomes easy to obtain the crystal phase and the glass phase as described above, and it becomes easy to obtain a crystallized glass having a small dimensional change due to heat treatment or temperature change. The reason for determining the composition range of the crystallized glass as described above is as follows.

SiO ₂ is a component that forms a skeleton of glass and a component that constitutes crystals, and its content is 55.0 to 70.0%. When the content of SiO ₂ is reduced, it is difficult to precipitate a predetermined crystal, and the content of SiO _{2 in} the glass phase is reduced, and the thermal expansion coefficient of the glass phase is increased in the positive direction. The thermal expansion coefficient changes due to the structural change of the glass phase, or the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction, making it difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. On the other hand, when the content increases, the meltability of the glass tends to deteriorate and it becomes difficult to obtain a homogeneous glass. A more preferable range of SiO ₂ is 60.0 to 70.0%.

Al ₂ O ₃ is a component that forms a glass skeleton as well as SiO ₂ and a component that constitutes crystals, and its content is 15.0 to 30.0%. When the content of Al ₂ O ₃ is reduced, it becomes difficult to precipitate a predetermined crystal, and the content of Al ₂ O _{3 in} the glass phase is reduced, and the thermal expansion coefficient of the glass phase is increased in the positive direction. The thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction, and crystallized glass with small dimensional change due to heat treatment or temperature change is obtained. It becomes difficult. On the other hand, when the content increases, the meltability of the glass tends to deteriorate and it becomes difficult to obtain a homogeneous glass. A more preferable range of Al ₂ O ₃ is 17.0 to 28.0%.

Li ₂ O is a component constituting a crystal and a glass modifying component, and its content is 2.0 to 6.0%. When the content of Li ₂ O decreases, it becomes difficult to precipitate desired crystals. On the other hand, when the content increases, the content of Li ₂ O in the glass phase increases and the thermal expansion coefficient of the glass phase increases in the positive direction, and the thermal expansion coefficient increases due to the structural change of the glass phase during heat treatment. It tends to change or the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction, making it difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. A more preferable range of Li ₂ O is 2.0 to 5.5%.

MgO and ZnO are components that dissolve in the crystal, and the content of these components is 0 to 2.0%, respectively. When the content of these components increases, in addition to β-quartz solid solution or β-eucryptite solid solution, dissimilar crystals such as spinel and garnite are likely to be precipitated, which may be damaged by heat treatment and temperature changes during use. . More preferable ranges of MgO and ZnO are 0 to 1.5%, respectively.

TiO ₂ and ZrO ₂ are nucleation components for precipitating crystals in the crystallization step, and the contents of these components are 0 to 4.0%, respectively. When the content of these components increases, it becomes easy to devitrify when the glass is melted and molded, and it becomes difficult to obtain a homogeneous glass. More preferable ranges of TiO ₂ and ZrO ₂ are 0 to 3.5%, respectively. When the total amount of TiO ₂ and ZrO ₂ is too small, it becomes difficult to obtain the desired crystallinity, the nucleation action becomes insufficient, and crystals having a desired particle diameter cannot be obtained. The β-quartz solid solution or β-eucryptite solid solution deposited on the glass is likely to transfer to the β-spodumene solid solution at a low temperature. As a result, the thermal expansion coefficient of the crystallized glass approaches 0 × 10 ⁻⁷ / ° C. (zero). It becomes difficult to obtain crystallized glass with small dimensional change due to temperature change. On the other hand, if the total amount of TiO ₂ and ZrO ₂ is too large, the glass tends to be devitrified when it is melted and molded, and it becomes difficult to obtain a homogeneous glass. The total amount of TiO ₂ and ZrO ₂ is more preferably 1.5 to 6.0%.

P ₂ O ₅ is a component that facilitates nucleation of glass, and its content is 0 to 4.0%. When the content of P ₂ O ₅ is increased, the glass is likely to be phase-separated and it is difficult to obtain a homogeneous glass. A preferable range of P ₂ O ₅ is 0 to 3.0%.

BaO is a component that lowers the viscosity of glass and improves glass meltability and formability, and its content is 0 to 2.0%. When the content of BaO increases, it becomes easy to devitrify when the glass is melted and molded, and it becomes difficult to obtain a homogeneous glass. A more preferable range of BaO is 0 to 1.8%.

Na ₂ O and K ₂ O are components that lower the viscosity of the glass and improve the glass melting property and moldability, and the content of these components is 0 to 4.0%, respectively. When the content of these components increases, the thermal expansion coefficient of the glass phase increases in the positive direction, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. More preferable ranges of Na ₂ O and K ₂ O are 0 to 2.0%, respectively.

In addition, SrO, CaO, B ₂ O ₃ and the like, which are components that lower the viscosity of the glass and improve the glass meltability and formability, and SnO ₂ , Cl, which are clarifiers, within a range that does not impair the predetermined characteristics. , Sb ₂ O ₃ , As ₂ O _{3 and the} like can be contained in a total amount of up to 10%. When the content of these components increases, the thermal expansion coefficient of the glass phase increases in the positive direction, the thermal expansion coefficient changes due to the structural change of the glass phase during heat treatment, or the thermal expansion coefficient of the crystallized glass increases. It becomes difficult to obtain crystallized glass with small dimensional change due to heat treatment or temperature change. Moreover, it becomes difficult to deposit desired crystals.

The crystallized glass of the present invention can be produced as follows.

First, in terms of mass percentage, SiO ₂ 55.0-70.0%, Al ₂ O ₃ 15.0-30.0%, Li ₂ O 2.0-6.0%, MgO 0-2.0%, ZnO 0-2.0%, TiO ₂ 0-4.0%, ZrO ₂ 0-4.0%, P ₂ O ₅ 0-4.0%, BaO 0-2.0%, Na ₂ O 0- A glass raw material is prepared so as to have a composition of 4.0% and K ₂ O 0 to 4.0%. In addition, you may add the component, clarifier, etc. for improving the meltability and moldability of glass as needed.

Next, the prepared glass raw material is melted at a temperature of 1550 to 1750 ° C. and then molded to obtain crystalline glass. In addition, as a shaping | molding method, it can shape | mold by various shaping | molding methods, such as a float method, a press method, and a roll-out method.

Subsequently, the formed crystalline glass is heat-treated at 600 to 800 ° C. for 1 to 10 hours to form crystal nuclei, and further heat-treated at 800 to 1000 ° C. for 0.5 to 5 hours to form Li ₂ as a main crystal. By precipitating O.Al ₂ O ₃ .nSiO ₂ -based crystals, the crystallized glass of the present invention can be obtained.

In addition, if the nucleation temperature is too high, too low, or if the nucleation time is too short, the nucleation action becomes insufficient, and crystals having a desired particle diameter cannot be obtained, and are precipitated when the crystals are precipitated. β-quartz solid solution or β-eucryptite solid solution is likely to transfer to β-spodumene solid solution at low temperature, and as a result, the thermal expansion coefficient of crystallized glass becomes difficult to approach 0 × 10 ⁻⁷ / ° C (zero). It becomes difficult to obtain crystallized glass with small dimensional change due to temperature change. In addition, if the nucleation time is too long, the effect of nucleation does not change, which increases the manufacturing cost.

On the other hand, if the crystallization temperature is too high, the precipitated β-quartz solid solution or β-eucryptite solid solution is easily transferred to the β-spodumene solid solution. As a result, the thermal expansion coefficient of the crystallized glass is 0 × 10 ^{− It} becomes difficult to approach ⁷ / ° C. (zero), and it becomes difficult to obtain crystallized glass with small dimensional change due to temperature change. On the other hand, if the crystallization temperature is too low or the crystallization time is too short, the degree of crystallinity becomes too low, and the thermal expansion coefficient of the crystallized glass tends to increase in the negative direction. Easy to grow. Further, if the crystallization time is too long, the effect of crystallization does not change, leading to an increase in manufacturing cost.

In addition, as described above, the crystallized glass of the present invention adjusts the kind of crystal to be precipitated, the degree of crystallinity (ratio of crystals to be precipitated), the composition of crystals, the ratio of glass phase, the composition of glass phase, and the like. The difference in thermal expansion coefficient before and after heat treatment (Δα) is reduced, and the thermal expansion coefficient after heat treatment of crystallized glass at −40 to 80 ° C. after heat treatment is close to 0. Dimensional change due to can be suppressed.

Further, the obtained crystallized glass may be subjected to post-processing such as cutting, polishing, and film formation.

Hereinafter, the crystallized glass of the present invention will be described in detail based on examples.

Table 1 shows examples and comparative examples of the present invention.

Each sample in the table was prepared as follows.

First, raw materials were prepared so as to have the glass composition shown in Table by mass%, mixed uniformly, and then put in a platinum crucible and melted at 1600 ° C. for 20 hours. Next, the molten glass is poured onto a carbon surface plate, formed into a 5 mm-thick plate using a roller, and then cooled to 700 ° C. to room temperature using a slow cooling furnace at a cooling rate of 100 ° C./hour for crystallinity. A glass plate was produced.

Next, the obtained crystalline glass plate was subjected to nucleation treatment at 780 ° C. for 1 hour, followed by crystallization treatment at 925 ° C. for 1 hour, cooling to room temperature, and crystallization. Glass was produced and used as each sample.

The rate of temperature increase from room temperature to the nucleation temperature is 250 ° C./hour, the rate of temperature increase from the nucleation temperature to the crystal growth temperature is 54 ° C./hour, and the rate of temperature decrease from the crystal growth temperature to room temperature is 54 ° C./hour. It was time.

For each sample obtained in this way, the composition of crystal phase, glass phase and crystallized glass, crystal type, crystallinity, solid solubility n, thermal expansion coefficient of crystal phase, thermal expansion coefficient before and after heat treatment The difference and dimensional change, and the thermal expansion coefficient and dimensional change due to temperature change after heat treatment were measured.

As is apparent from Table 1, in the example, β-quartz solid solution having a negative thermal expansion coefficient was precipitated as a precipitated crystal, and the crystallinity was 75%. Further, the solid solubility n was as high as 7.6. Further, the difference (Δα) in the thermal expansion coefficient before and after the heat treatment was 0.09 × 10 ⁻⁷ / ° C., the change in the thermal expansion coefficient due to the heat treatment was small, and the dimensional change due to the heat treatment was as small as 0 mm. Furthermore, the coefficient of thermal expansion at −40 to 80 ° C. after heat treatment is as small as −0.09 × 10 ⁻⁷ / ° C., and the dimensional change due to temperature change after heat treatment is also as small as −2.2 × 10 ⁻⁵ mm. there were.

In contrast, in the comparative example, although β-quartz solid solution having a negative thermal expansion coefficient was precipitated, the crystallinity was as high as 80% and the solid solubility n was as low as 6.8. The difference (Δα) in the thermal expansion coefficient before and after the heat treatment was 0.35 × 10 ⁻⁷ / ° C., the change in the thermal expansion coefficient due to the heat treatment was large, and the dimensional change due to the heat treatment was also 0 mm. Furthermore, the coefficient of thermal expansion at −40 to 80 ° C. after heat treatment was as large as 0.48 × 10 ⁻⁷ / ° C., and the dimensional change due to temperature change after heat treatment was also as large as 11.5 × 10 ⁻⁵ mm. .

The crystal type, crystallinity, and solid solubility n were measured using an X-ray diffraction method (SmartLab, manufactured by Rigaku Corporation).

Specifically, regarding the degree of crystallinity, by analyzing the diffraction pattern of the crystallized glass obtained by the X-ray diffraction method by the Rietveld method, the crystal amount (mass of the β-quartz solid solution or β-eucryptite solid solution) %), The crystal content (mass%) of the ZrTiO ₄ -based crystals and the content (mass%) of the glass phase, and the total crystal content of each crystal phase was calculated as the crystallinity (mass%).

The solid solubility n was determined by the following procedure. First, the interplanar spacing of β-quartz solid solution or β-eucryptite solid solution is measured by X-ray diffraction. Next, the SiO ₂ content x (mol%) in the crystal phase is calculated from the formula (1) using the interplanar spacing measured by the X-ray diffraction method, and then the solid solubility n ( Molar ratio) was calculated.

Formula (1): SiO ₂ content x = (0.1004-d (406)) / 6.752 × 10 ⁻⁵
Formula (2): Solid solubility n = 2x / (100−x)
As described on pages 505-510 of the Journal of Chemical Society of Japan (1974), there is a gap between the SiO ₂ content in the β-quartz solid solution or β-eucryptite solid solution and the specific spacing in the crystal lattice. Since the proportional relationship is established, the SiO ₂ content x (mol%) in the crystal phase can be obtained by measuring the interplanar spacing. In the formula (1), d (406) represents the interplanar spacing (nm) of the (406) plane in the crystal lattice of β-quartz solid solution or β-eucryptite solid solution (hexagonal crystal).

Regarding the composition of the crystallized glass, the Li ₂ O content is determined by atomic absorption spectrometry, the B ₂ O ₃ content is determined by inductively coupled plasma (ICP) emission spectrometry, and the other component contents are determined by fluorescent X-ray analysis. Measured with

The composition of the crystal phase was determined by calculating the content of each component of the crystal phase from the solid solubility n calculated by the X-ray diffraction method and the crystal content of the ZrTiO ₄ crystal. Note that, regarding MgO and ZnO, the total amount contained in each crystallized glass was determined as a solid solution in β-quartz solid solution or β-eucryptite solid solution.

Regarding the composition of the glass phase, the content of each component contained in the remaining glass phase was determined by subtracting the content of each component of the crystal phase from the content of each component of the crystallized glass. _{Incidentally, SiO 2, Al 2 O 3} , Li 2 O, MgO, ZnO, components of TiO 2, except ZrO ₂ was determined as if all contained in the glass phase.

Regarding the thermal expansion coefficient of the crystal phase, the lattice constant (a-axis) of β-quartz solid solution or β-eucryptite solid solution was measured in the temperature range from 20 ° C. to 300 ° C. by the X-ray diffraction method (SmartLab, manufactured by Rigaku Corporation). (Temperature, c-axis length) is measured, the volume expansion coefficient is obtained by calculating the volume of the unit cell from the a-axis length and the c-axis length, and the thermal expansion coefficient is obtained by dividing the volume expansion coefficient by 3. Was calculated.

For dimensional changes due to heat treatment, the difference in thermal expansion coefficient (Δα) before and after heat treatment and dimensional changes before and after heat treatment were measured. For dimensional changes due to temperature changes after heat treatment, dimensional changes at −40 to 80 ° C. after heat treatment were measured. It was evaluated by doing.

Regarding the difference in thermal expansion coefficient before and after the heat treatment (Δα) and the dimensional change at −40 to 80 ° C. after the heat treatment, a sample processed into a cylindrical shape having a diameter of 4.0 mm and a length of 20 mm was prepared, and the −40 to The average thermal expansion coefficient at 80 ° C. was measured using a dilatometer. Subsequently, after the sample was heat-treated at 400 ° C. for 24 hours, the average thermal expansion coefficient and the expansion amount at −40 to 80 ° C. were measured again, and the difference in the average thermal expansion coefficient The difference (Δα) is shown, and the amount of expansion at −40 to 80 ° C. is shown as a dimensional change at −40 to 80 ° C. after the heat treatment.

Also, regarding the dimensional change before and after the heat treatment, the length of the sample before and after the heat treatment was measured using a differential transformer type displacement sensor, and the difference before and after the heat treatment was shown as a dimensional change.

The crystallized glass of the present invention is not limited to the etalon spacer application. For example, a substrate for an optical wavelength multiplexer / demultiplexer, a member for a precision scale such as a linear encoder position scale, a structural member for a precision instrument, It can also be used as a mirror substrate.

Claims (7)

1. A heat treatment is performed at a temperature of 300 ° C. to a glass transition point for 24 hours, a difference (Δα) in thermal expansion coefficient before and after the heat treatment is within ± 0.20 × 10 ⁻⁷ / ° C., and −40 after the heat treatment Crystallized glass having a coefficient of thermal expansion within 0 ± 0.3 × 10 ⁻⁷ / ° C. at ^˜80 ° C.
2. 2. The crystallized glass according to claim 1, wherein β-quartz solid solution or β-eucryptite solid solution is precipitated as the main crystal, and the crystallinity is 72 to 80% by mass percentage.
3. The solid solubility n of SiO ₂ in a β-quartz solid solution or β-eucryptite solid solution represented by Li ₂ O · Al ₂ O ₃ · nSiO ₂ is 6.9 or more in molar ratio. 3. The crystallized glass according to 1 or 2.
4. 4. The crystallized glass according to claim 1, wherein a thermal expansion coefficient of the crystal phase at 20 to 300 ° C. is −11 × 10 ⁻⁷ to 0 × 10 ⁻⁷ / ° C.
5. The crystal phase is, by mass percentage, SiO ₂ 65.0-80.0%, Al ₂ O ₃ 10.0-18.0%, Li ₂ O 3.0-6.0%, MgO 0-2.0. %, ZnO 0-2.0%, TiO ₂ 0.5-4.0%, ZrO ₂ 0.5-4.0%, P ₂ O ₅ 0-0.5% Item 5. The crystallized glass according to any one of Items 1 to 4.
6. The glass phase is, by mass percentage, SiO ₂ 30.0-50.0%, Al ₂ O ₃ 31.0-45.0%, Li ₂ O 1.0-3.0%, MgO 0-1.0. %, ZnO 0-1.0%, TiO ₂ 0-5.0%, ZrO ₂ 0-5.0%, P ₂ O ₅ 0-9.0%, BaO 0-8.0%, Na ₂ O 6. The crystallized glass according to claim 1, wherein the crystallized glass is 0 to 4.0% and K ₂ O is 0 to 4.0%.
7. By mass percentage, SiO ₂ 55.0-70.0%, Al ₂ O ₃ 15.0-30.0%, Li ₂ O 2.0-6.0%, MgO 0-2.0%, ZnO 0 -2.0%, TiO ₂ 0-4.0%, ZrO ₂ 0-4.0%, P ₂ O ₅ 0-4.0%, BaO 0-2.0%, Na ₂ O 0-4. 7. The crystallized glass according to claim 1, which has a composition of 0% and K ₂ O 0 to 4.0%.