JP6627760B2 - Crystallized glass - Google Patents

Description

  The present invention relates to crystallized glass.

  Since a resonator using optical interference functions as a narrow-band wavelength filter, it 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. The etalon is composed of a pair of parallel flat half mirrors having high flatness and parallelism, and the light incident on the etalon causes multiple interference between the half mirrors, so that light of a wavelength corresponding to the interference order is periodically emitted. It has the property of transmitting light.

  The space between the half mirrors 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 whose refractive index changes very little with temperature. When the cavity is filled with air, a spacer is arranged between the half mirrors to form an air gap.

  Further, in order to prevent the space 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.

In joining the spacers and the half mirrors, they are joined by an optical contact method that does not require an adhesive that causes a large change in the space between the half mirrors due to a temperature change during use. In addition, in the optical contact method, in order to increase the bonding strength of the spacer and the half mirror in a short time, the spacer and the half mirror may be joined to each other by heating to a temperature equal to or lower than the glass transition point after the spacer and the half mirror.
JP 2004-29723 A

  However, when the spacer and the half mirror are joined while being heated, the dimension of the spacer does not change due to the heat treatment during the joining, but the dimension of the spacer changes due to a temperature change during use after the heat treatment. There has been a problem that the distance between the two 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 when subjected to a heat treatment at a temperature equal to or lower than the glass transition point and thereafter exposed to an environment in which the temperature changes. .

That is, the crystallized glass of the present invention is subjected to heat treatment at a temperature of 300 ° C. to the glass transition point for 24 hours, and the difference (Δα) between the thermal expansion coefficients before and after the heat treatment is within ± 0.20 × 10 ⁻⁷ / ° C. And a 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 is subjected to a heat treatment at a temperature equal to or lower than the glass transition point, and can suppress a dimensional change due to a temperature change even when exposed to an environment in which the temperature changes. Therefore, it can be particularly suitably used as a spacer for an etalon requiring dimensional stability due to a temperature change.

The crystallized glass of the present invention is subjected to a heat treatment at a temperature of 300 ° C. to a glass transition point for 24 hours, and a difference (Δα) in a coefficient of thermal expansion before and after the heat treatment is within ± 0.20 × 10 ⁻⁷ / ° C. 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 in the ^{-40~80 ℃ 0 ± 0.3 × 10 -7} / ℃ within, i.e. by the ^{-0.3 × 10 -7 /℃~+0.3×10 -7 / ℃} , The change in the thermal expansion coefficient of the crystallized glass due to the temperature change is suppressed, and the dimensional change of the crystallized glass is suppressed. Therefore, even if heat treatment is performed at a temperature equal to or lower than the glass transition point, and then the film is exposed to an environment in which the temperature changes, crystallized glass having 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 preferred range of the thermal expansion coefficient of -40 to 80 ° C. after the heat treatment 0 ± 0.25 × ^{10 -7} / ℃ within, i.e. -0.25 × ^{10 -7} /℃~+0.25×10 ^-7 / ° C.

In order to reduce the difference (Δα) between the coefficients of thermal expansion before and after the heat treatment and to set the coefficient of thermal expansion between −40 and 80 ° C. after the heat treatment to be within 0 ± 0.3 × 10 ⁻⁷ / ° C. In the case of fossilized glass, the type of crystal to be precipitated, the degree of crystallinity (the ratio of the crystal to be precipitated), the composition of the crystal, the ratio of the glass phase, the composition of the glass phase and the like may be adjusted.

Specifically, as a kind of the main crystal, β-quartz solid solution or β-eucryptite solid solution is precipitated, and the crystallinity is preferably crystallized glass having a mass percentage of 72 to 80%. . A more preferred range of crystallinity is 73-79% by mass. As a main crystal, a β-quartz solid solution or a β-eucryptite solid solution having a negative coefficient of thermal expansion is precipitated, and the crystallinity is set to 73 to 79% by mass percentage, whereby a negative coefficient of thermal expansion of a crystal phase is obtained. And the positive coefficient of thermal expansion of the glass phase are offset, and the coefficient of thermal expansion of the crystallized glass can be brought close to 0 × 10 ⁻⁷ / ° C. (zero), so that crystallized glass with small dimensional change due to temperature change can be easily obtained. Become. Further, in the crystallized glass, since the ratio of the glass phase which causes a structural change due to the heat treatment can be reduced, the change in the coefficient of thermal expansion due to the heat treatment can be suppressed, and the crystallized glass having a small dimensional change due to the heat treatment can be easily obtained. If the crystallinity is too low, the thermal expansion coefficient of the crystalline phase tends to increase in the negative direction, and the content of SiO ₂ in 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 canceled out, 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 is too high, the coefficient of thermal expansion of the crystallized glass tends to change from negative to positive, and furthermore, the content of SiO ₂ in the glass phase decreases, and the thermal expansion of the glass phase decreases. The coefficient tends to increase. Therefore, the coefficient of thermal expansion of the crystal phase and the coefficient of thermal expansion of the glass phase are not offset, and the coefficient of thermal expansion of the crystallized glass tends to increase in the positive direction, and the dimensional change due to temperature change is likely 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. It is preferable that it is above. By setting the solid solubility n to 6.9 or more in molar ratio, the coefficient of thermal expansion of the β-quartz solid solution or β-eucryptite solid solution is suppressed from becoming too large in the negative direction, and -40 to 40 after the heat treatment. The coefficient of thermal expansion of the crystallized glass at 80 ° C. can approach 0 × 10 ⁻⁷ / ° C. (zero). If the solid solubility n is too small, the coefficient of thermal expansion of the β-quartz solid solution or β-eucryptite solid solution tends to be too large in the negative direction, and the difference (Δα) between the coefficients of thermal expansion before and after the heat treatment is reduced. However, it is difficult to make the thermal expansion coefficient of the crystallized glass close to 0 × 10 ⁻⁷ / ° C., and it is 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 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 from −11 × 10 ^{−7 to} 0 × 10 ⁻⁷ / ° C. If the thermal expansion coefficient of the crystal phase becomes too large in the negative direction, the difference in thermal expansion coefficient before and after the heat treatment (Δα) is reduced, and the heat of the crystallized glass at −40 to 80 ° C. after the heat treatment is reduced. It becomes difficult to make the expansion coefficient close to 0 × 10 ⁻⁷ / ° C., and it becomes difficult to obtain 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 has a SiO ₂ content of 65.0 to 80.0%, an Al ₂ O ₃ content of 10.0 to 18.0%, and a Li ₂ O content of 3.0 to 6% by mass percentage. _{.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. Preferably, it contains 5%. If the crystal phase has such a composition, β-quartz solid solution or β-eucryptite solid solution precipitates as the type of main crystal, and the crystallinity, solid solubility n, and thermal expansion of the crystal are increased. Since the coefficient tends to be in the above range, crystallized glass having a small dimensional change due to heat treatment or temperature change is easily obtained. The reasons for determining the composition range of the crystal phase as described above are 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 is increased, 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 canceled out, and the thermal expansion coefficient of the crystallized glass is reduced. It tends to increase in the positive direction, making it difficult to obtain crystallized glass with small dimensional changes due to heat treatment and temperature changes. On the other hand, when the content is small, 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 be small, and the heat of the crystal phase is low. 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 is reduced while reducing the difference (Δα) between the coefficients of thermal expansion before and after the heat treatment. To 0 × 10 ⁻⁷ / ° C., making it difficult to obtain a crystallized glass having a small dimensional change due to a temperature change. A more preferred 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 be too large in the negative direction. While making the difference (Δα) small, it is difficult to make the thermal expansion coefficient of the crystallized glass at −40 to 80 ° C. after the heat treatment close to 0 × 10 ⁻⁷ / ° C., and the crystal whose dimensional change due to temperature change is small. It becomes difficult to obtain glass. On the other hand, when the content is small, 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 canceled out, and the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction. In addition, it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Al ₂ O ₃ is from 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 be too large in the negative direction. While making (Δα) small, it becomes difficult to make the coefficient of thermal expansion of the crystallized glass at −40 to 80 ° C. after heat treatment close to 0 × 10 ⁻⁷ / ° C., and crystallization with small dimensional change due to temperature change It becomes difficult to obtain glass. On the other hand, when the content is small, 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 canceled out, and the thermal expansion coefficient of the crystallized glass tends to increase in the positive direction. In addition, it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Li ₂ O is a 3.0 to 5.5%.

  MgO and ZnO are components that form a solid solution with the crystal in the crystal phase, and the content of each of these components is 0 to 2.0%. When the content of these components increases, in addition to the β-quartz solid solution or β-eucryptite solid solution, heterogeneous crystals such as spinel and garnite are also likely to precipitate, and the thermal expansion coefficient of the crystal phase increases, The crystallized glass may be damaged by temperature changes during use. The more preferred ranges of MgO and ZnO are each 0 to 1.5%.

TiO ₂ and ZrO ₂ are crystal nucleus components in the crystal phase, and the content of each of these components is 0.5 to 4.0%. When the content of these components increases, heterogeneous crystals tend to precipitate, and the thermal expansion coefficient of the crystal phase may increase, or the crystallized glass may be damaged by heat treatment or a temperature change during use. On the other hand, when the content of these components is reduced, it becomes difficult to obtain a desired degree of crystallinity, or nucleation becomes insufficient, crystals having a desired particle size 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 a low temperature. As a result, the coefficient of thermal expansion of crystallized glass is 0 × 10 ⁻⁷ / ° C. (zero). , And it is difficult to obtain a crystallized glass having a small dimensional change due to a temperature change. A more preferable range of the TiO ₂ and ZrO ₂ are each 0.5 to 3.5%.

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, heterogeneous crystals are likely to be precipitated, the thermal expansion coefficient of the crystal phase is increased, or the crystallized glass may be damaged by heat treatment or a temperature change 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 SiO ₂ content of 30.0 to 50.0%, an Al ₂ O ₃ content of 31.0 to 45.0%, and a Li ₂ O content of 1.0 to ₃ in mass percentage. _{.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 0~4.0%} , preferably contains K 2 O 0~4.0%. If the glass phase has such a composition, the structural change of the glass phase due to the heat treatment is less likely to occur, and crystallized glass having a small dimensional change due to the heat treatment is easily obtained. The reasons for determining the composition range of the glass phase as described above are as follows.

SiO ₂ is a component that forms the skeleton of glass in the glass phase, and its content is 30.0 to 50.0%. When the content of SiO ₂ is increased, 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. This makes it difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. On the other hand, when the content is small, the thermal expansion coefficient of the glass phase tends to increase, and 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. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of SiO ₂ is 32.0 to 48.0%.

Al ₂ O ₃ , like SiO ₂ , is a component that forms a glass skeleton in a 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, and the thermal expansion coefficients of the crystal phase and the glass phase are not canceled out, and the thermal expansion coefficient of the crystallized glass increases in the negative direction. This tends to make it difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. On the other hand, when the content is small, the thermal expansion coefficient of the glass phase tends to increase, and 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. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Al ₂ O ₃ is from 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 content of Li ₂ O increases, the coefficient of thermal expansion of the glass phase tends to increase, and the coefficient of thermal expansion changes due to structural change of the glass phase during heat treatment, or the coefficient of thermal expansion of crystallized glass is positive. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. On the other hand, when the content is small, 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. In addition, it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred 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 each of these components is 0 to 1.0%. When the content of these components increases, the thermal expansion coefficient of the glass phase tends to increase, and 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, making it difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. In addition, the glass tends to be devitrified, making it difficult to obtain a homogeneous glass. The more preferred ranges of MgO and ZnO are each 0 to 0.8%.

TiO ₂ and ZrO ₂ are glass modifying components in the glass phase, and the content of each of these components is 0 to 5.0%. When the content of these components is large, the glass tends to be devitrified, and it is difficult to obtain a homogeneous glass. A more preferable range of the TiO ₂ and ZrO ₂ are each from 0 to 4.0%.

P ₂ O ₅ is a component that forms the skeleton of glass in the glass phase, and its content is 0 to 9.0%. When the content of P ₂ O ₅ increases, the coefficient of thermal expansion of the crystallized glass tends to increase significantly in the positive direction, and it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. In addition, the glass tends to be devitrified, making it difficult to obtain a 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 coefficient of thermal expansion of the crystallized glass tends to increase significantly in the positive direction, and it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. In addition, the glass tends to be devitrified, making it difficult to obtain a homogeneous glass. A more preferred 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 each of these components is 0 to 4.0%. When the content of these components increases, the thermal expansion coefficient of the glass phase increases in the positive direction, and 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. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Na ₂ O and _{K 2} O are respectively 0 to 3.0%.

In addition, the crystallized glass of the present invention has, by mass percentage, 55.0 to 70.0% of SiO _2, 15.0 to 30.0% of Al ₂ O _{3, and} 2.0 to 6.0% of Li ₂ O; _{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 0~4.0%} , preferably has a composition of K 2 O 0~4.0%. If the crystallized glass has such a composition, the crystallized glass and the glassy phase are easily formed as described above, and the crystallized glass having a small dimensional change due to heat treatment or temperature change is easily obtained. The reasons for determining the composition range of the crystallized glass as described above are as follows.

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

Al ₂ O ₃ is a component that forms a skeleton of glass as well as SiO _2, and is a component that constitutes a crystal, and its content is 15.0 to 30.0%. When the content of Al ₂ O ₃ decreases, the precipitation of a predetermined crystal becomes difficult, and the content of Al ₂ O _{3 in} the glass phase decreases, and the thermal expansion coefficient of the glass phase increases in the positive direction. The coefficient of thermal expansion changes due to the structural change of the glass phase during heat treatment, and the coefficient of thermal expansion of crystallized glass tends to increase in the positive direction. It becomes difficult. On the other hand, when the content is large, the melting property of the glass tends to deteriorate, and it is difficult to obtain a homogeneous glass. A more preferred range for Al ₂ O ₃ is 17.0 to 28.0%.

Li ₂ O is a component constituting the crystal and is also a glass modifying component, and its content is 2.0 to 6.0%. If the content of Li ₂ O is small, it becomes difficult to deposit desired crystals. On the other hand, if 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. Or the coefficient of thermal expansion of the crystallized glass tends to increase in the positive direction, making it difficult to obtain a crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Li ₂ O is a 2.0 to 5.5%.

  MgO and ZnO are components that form a solid solution in the crystal, and the content of each of these components is 0 to 2.0%. When the content of these components is increased, in addition to the β-quartz solid solution or β-eucryptite solid solution, heterogeneous crystals such as spinel and garnite are also likely to precipitate, and may be damaged by heat treatment or temperature change during use. . The more preferred ranges of MgO and ZnO are each 0 to 1.5%.

TiO ₂ and ZrO ₂ are nucleation components for precipitating crystals in the crystallization step, and the content of each of these components is 0 to 4.0%. When the content of these components is large, the glass tends to be devitrified when being melted and formed, and it is difficult to obtain a homogeneous glass. A more preferable range of the TiO ₂ and ZrO ₂ are each from 0 to 3.5%. If the total amount of TiO ₂ and ZrO ₂ is too small, it is difficult to obtain a desired degree of crystallinity or the nucleating action becomes insufficient, and crystals having a desired particle size cannot be obtained. The β-quartz solid solution or β-eucryptite solid solution easily precipitates at low temperature and easily transforms to β-spodumene solid solution, and as a result, the thermal expansion coefficient of the crystallized glass approaches 0 × 10 ⁻⁷ / ° C. (zero). It becomes difficult to obtain crystallized glass having a small dimensional change due to a 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 being melted and formed, and it is difficult to obtain a homogeneous glass. More preferably, the total amount of TiO ₂ and ZrO ₂ is 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 phase of the glass is easily separated, and it is difficult to obtain a homogeneous glass. The preferred range of P ₂ O ₅ is 0 to 3.0%.

  BaO is a component that lowers the viscosity of the glass and improves the glass meltability and moldability, and its content is 0 to 2.0%. When the content of BaO is large, the glass tends to be devitrified when being melted and formed, and it is 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 reduce the viscosity of glass to improve glass meltability and moldability, and the content of each of these components is 0 to 4.0%. When the content of these components increases, the thermal expansion coefficient of the glass phase increases in the positive direction, and 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. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. A more preferred range of Na ₂ O and _{K 2} O are respectively 0 to 2.0%.

Further, SrO, CaO, B ₂ O _3, etc., which are components that reduce the viscosity of the glass and improve the glass meltability and formability, and SnO ₂ , Cl, which are fining agents, as long as the predetermined characteristics are not impaired. , Sb ₂ O ₃ , As ₂ O _3, etc., 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, and 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. And it becomes difficult to obtain crystallized glass having a small dimensional change due to heat treatment or temperature change. In addition, it becomes difficult for desired crystals to precipitate.

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

First, 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 0-0 A glass raw material is prepared so as to have a composition of 4.0% and K ₂ O of 0 to 4.0%. In addition, you may add the component for improving the meltability and formability of glass, a fining agent, etc. as needed.

  Next, the prepared glass raw material is melted at a temperature of 1550 to 1750 ° C., and then molded to obtain a crystalline glass. In addition, as a molding method, it can be molded by various 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 a crystal nucleus, and further heat-treated at 800 to 1000 ° C. for 0.5 to 5 hours to obtain Li ₂ as a main crystal. The crystallized glass of the present invention can be obtained by precipitating O.Al ₂ O ₃ .nSiO ₂ based crystals.

If the nucleation temperature is too high or too low, or if the nucleation time is too short, the nucleation action becomes insufficient, crystals having a desired particle size cannot be obtained, and crystals are precipitated when the crystals are precipitated. β-quartz solid solution or β-eucryptite solid solution tends to be transformed into β-spodumene solid solution at a low temperature, and as a result, the thermal expansion coefficient of the crystallized glass is hard to approach 0 × 10 ⁻⁷ / ° C. (zero). In addition, it becomes difficult to obtain crystallized glass having a small dimensional change due to a temperature change. If the nucleation time is too long, the effect of nucleation does not change, resulting in an increase in manufacturing cost.

On the other hand, if the crystallization temperature is too high, the precipitated β-quartz solid solution or β-eucryptite solid solution tends to be transformed into β-spodumene solid solution, and as a result, the thermal expansion coefficient of the crystallized glass becomes 0 × 10 ^{−. 7} / ° C. (zero), making it difficult to obtain a crystallized glass having a small dimensional change due to a 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, and the dimensional change due to temperature change is reduced. Easy to grow. If the crystallization time is too long, the effect of crystallization does not change, which leads to an increase in manufacturing cost.

  Further, as described above, the crystallized glass of the present invention is capable of adjusting the type of the crystal to be precipitated, the degree of crystallinity (the ratio of the crystal to be precipitated), the composition of the crystal, the ratio of the glass phase, the composition of the glass phase, and the like. Therefore, the difference (Δα) in the coefficient of thermal expansion before and after the heat treatment is reduced, and the coefficient of thermal expansion of the crystallized glass at −40 to 80 ° C. after the heat treatment is close to 0, so that the heat treatment and the temperature change Dimensional change due to the above can be suppressed.

  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 the table in terms of mass%, and after mixing uniformly, the mixture was put in a platinum crucible and melted at 1600 ° C. for 20 hours. Next, the molten glass was poured out onto a carbon platen, formed into a plate having a thickness of 5 mm using a roller, and then cooled from 700 ° C. to room temperature at a rate of 100 ° C./hour using a slow cooling furnace to obtain crystallinity. A glass plate was produced.

  Next, the obtained crystalline glass plate is subjected to a nucleation treatment at 780 ° C. for 1 hour, then a crystallization treatment at a crystallization temperature of 925 ° C. for 1 hour, and cooled to room temperature. Glass was prepared and used as each sample.

  The rate of temperature rise from room temperature to the nucleation temperature was 250 ° C./hour, the rate of temperature rise from the nucleation temperature to the crystal growth temperature was 54 ° C./hour, and the rate of temperature decrease from the crystal growth temperature to room temperature was 54 ° C./hour. Time.

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

As is clear from Table 1, in Examples, β-quartz solid solution having a negative coefficient of thermal expansion was precipitated as precipitated crystals, and the crystallinity was 75%. The solid solubility n was as high as 7.6. The difference (Δα) between the coefficients of thermal expansion before and after the heat treatment was 0.09 × 10 ⁻⁷ / ° C., and the change in the coefficient of thermal expansion 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 the heat treatment is as small as −0.09 × 10 ⁻⁷ / ° C., and the dimensional change due to the temperature change after the heat treatment is as small as −2.2 × 10 ⁻⁵ mm. there were.

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

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

Specifically, regarding the degree of crystallinity, the diffraction pattern of the crystallized glass obtained by the X-ray diffraction method is analyzed by the Rietveld method, and the crystal amount (mass) of the β-quartz solid solution or β-eucryptite solid solution is determined. %), The crystal amount (% by mass) of the ZrTiO ₄ system crystal and the content of the glass phase (% by mass) were calculated, and the total of the crystal amounts of the respective crystal phases was calculated as the crystallinity (% by mass).

The solid solubility n was determined according to the following procedure. First, the plane spacing of the β-quartz solid solution or β-eucryptite solid solution is measured by the X-ray diffraction method. Next, using the lattice distance measured by X-ray diffraction method, calculates a SiO ₂ content x (mole%) in the crystalline phase from the equation (1), followed by solid solubility equation (2) n ( (Molar ratio) was calculated.

Equation (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 the Chemical Society of Japan (1974), the difference between the SiO ₂ content in the β-quartz solid solution or β-eucryptite solid solution and the specific interplanar spacing in the crystal lattice was determined. Since the proportional relationship holds, the SiO ₂ content x (mol%) in the crystal phase can be obtained by measuring the plane spacing. In the formula (1), d (406) represents the plane spacing (nm) of the (406) plane in the crystal lattice of β-quartz solid solution or β-eucryptite solid solution (hexagonal).

Regarding the composition of the crystallized glass, the content of Li ₂ O was determined by atomic absorption spectrometry, the content of B ₂ O _{3 was} determined by inductively coupled plasma (ICP) emission spectrometry, and the content of other components was determined by fluorescent X-ray analysis. Was measured.

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 amount of the ZrTiO ₄ system crystal. Note that MgO and ZnO were determined as those in which the total amount contained in the crystallized glass was dissolved 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 residual 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. The components other than SiO ₂ , Al ₂ O ₃ , Li ₂ O, MgO, ZnO, TiO ₂ , and ZrO ₂ were all determined to be contained in the glass phase.

  Regarding the thermal expansion coefficient of the crystalline phase, the lattice constant (a-axis) of β-quartz solid solution or β-eucryptite solid solution was determined by X-ray diffraction (SmartLab manufactured by Rigaku Corporation) in a temperature range of 20 ° C. to 300 ° C. Length, c-axis length), 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 the dimensional change due to heat treatment, the difference in thermal expansion coefficient (Δα) before and after heat treatment and the dimensional change before and after heat treatment are measured. For the dimensional change due to temperature change after heat treatment, the dimensional change at -40 to 80 ° C. after heat treatment is measured. It was evaluated by doing.

  The difference in thermal expansion coefficient (Δα) before and after the heat treatment and the dimensional change at −40 to 80 ° C. after the heat treatment were determined by preparing a column-shaped sample having a diameter of 4.0 mm and a length of 20 mm. The average coefficient of thermal expansion at 80 ° C. was measured using a dilatometer. Subsequently, after heat-treating the sample at 400 ° C. for 24 hours, the average coefficient of thermal expansion and the amount of expansion at −40 to 80 ° C. were measured again, and the difference in the average coefficient of thermal expansion was calculated as the difference between the coefficient of thermal expansion before and after the heat treatment. The amount of expansion at −40 to 80 ° C. was shown as a dimensional change at −40 to 80 ° C. after the heat treatment.

  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 the dimensional change.

The crystallized glass of the present invention is not limited to spacer applications for etalons, for example, substrates for optical wavelength multiplexer / demultiplexers, members for precision scales such as linear encoder position scales, structural members for precision equipment, precision It is also possible to use as a base material of a mirror.

Claims (4)

If the 300 ° C. ~ Tsu rows 24 hours heat treatment at a temperature of glass transition point, the difference in thermal expansion coefficient between before and after heat treatment ([Delta] [alpha]) is within ± 0.20 × 10 -7 ^/ ℃, and the heat treatment Ri der thermal expansion coefficient of 0 ± 0.3 × ^{10 -7} / ℃ within at -40 to 80 ° C. after,
Β-quartz solid solution or β-eucryptite solid solution is precipitated as a main crystal, and the crystallinity is 72 to 79% by mass percentage,
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 or more in molar ratio,
In terms of mass percentage, SiO ₂ 55.0 to 70.0%, Al ₂ O ₃ 15.0 to 30.0%, Li ₂ O 2.0 to 6.0%, MgO 0 to 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. _0%, K 2 O _0~4.0% of the crystallized glass that have a composition. The crystallized glass according to claim 1, wherein the crystal phase has a thermal expansion coefficient of -11 x ^{10-7 to} 0 x ^10-7 / C at 20 to 300C. The crystal phase is, by mass percentage, 65.0 to 80.0% of SiO _2, 10.0 to 18.0% of Al ₂ O _3, 3.0 to 6.0% of Li ₂ O, and 0 to 2.0 of MgO. _{%, ZnO 0~2.0%, TiO 2} 0.5~4.0%, ZrO 2 0.5~4.0%, claims, characterized in that the _P 2 O 5 _0~0.5% Item 3. The crystallized glass according to item 1 or 2 . The glass phase is, by mass percentage, 30.0 to 50.0% of SiO _2, 31.0 to 45.0% of Al ₂ O ₃ , 1.0 to 3.0% of Li ₂ O, and 0 to 1.0 of MgO. %, 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 0 to _4.0%, the crystallized glass according to any one of claims 1 to 3, characterized in that the K 2 O 0 to 4.0%.