JP6273549B2 - Glass material manufacturing method, glass material manufacturing apparatus and glass material - Google Patents

Description

  The present invention relates to a glass material manufacturing method, a glass material manufacturing apparatus, and a glass material.

  In recent years, research on a containerless floating method has been made as a method for producing a glass material. For example, in Patent Document 1, a barium titanium ferroelectric sample suspended in a gas floating furnace is irradiated with a laser beam, heated and melted, and then cooled, whereby the barium titanium ferroelectric sample is cooled to glass. Is described. Thus, in the containerless floating method, since the progress of crystallization due to contact with the wall surface of the container can be suppressed, even a material that could not be vitrified by a conventional manufacturing method using a container. It may be vitrified. Therefore, the containerless floating method is a method that should be noted as a method capable of producing a glass material having a novel composition.

JP 2006-248801 A

  When manufacturing a glass material by the containerless floating method, devitrification occurs when the molten glass comes into contact with the mold, and a homogeneous glass material may not be manufactured.

  A main object of the present invention is to provide a method capable of stably producing a glass material not containing crystals by a containerless floating method.

In the method for producing a glass material according to the present invention, the glass raw material is heated in a state where the glass raw material is suspended and held above the molding surface by ejecting gas from a gas ejection hole opened on the molding surface of the mold. After melting and obtaining molten glass, the molten glass is cooled to obtain a glass material. The glass material has a first surface facing the molding surface and a second surface located on the opposite side of the molding surface. The first surface includes a central portion and a peripheral portion located outside the central portion. A glass material that satisfies R ₂ <R ₃ <R ₁ is formed when the radius of curvature of the central portion is R ₁ , the radius of curvature of the peripheral portion is R _2, and the radius of curvature of the second surface is R _3. Gas is ejected from the gas ejection holes at a flow velocity and flow rate.

The apparatus for producing a glass material according to the present invention heats a glass material in a state in which the glass material is suspended and held above the molding surface by ejecting gas from a gas ejection hole that opens on the molding surface of the mold. After melting and obtaining molten glass, it is an apparatus for producing a glass material by cooling the molten glass. The glass material has a first surface facing the molding surface and a second surface located on the opposite side of the molding surface. The first surface includes a central portion and a peripheral portion located outside the central portion. Apparatus for manufacturing a glass material according to the present invention, the curvature radius of the central portion of the first surface and R _1, the curvature radius of the peripheral portion and R _2, the radius of curvature of the second surface when the R ₃ Gas is ejected from the gas ejection holes at a flow rate and a flow rate at which a glass material satisfying R ₂ <R ₃ <R ₁ is formed.

In the glass material according to the present invention, the glass raw material is heated and melted in a state where the glass raw material is floated and held above the molding surface by ejecting gas from the gas ejection holes opened in the molding surface of the molding die. It is a glass material manufactured by cooling molten glass after obtaining molten glass. The glass material according to the present invention has a first surface facing the molding surface and a second surface located on the opposite side of the molding surface. The first surface includes a central portion and a peripheral portion located outside the central portion. The glass material of the present invention, the curvature radius of the central portion and R _1, the curvature radius of the peripheral portion and R _2, the radius of curvature of the second surface when the _{R 3, R 2 <R 3} <R ₁ is satisfied.

  ADVANTAGE OF THE INVENTION According to this invention, the method which can manufacture the glass material which does not contain a crystal | crystallization stably by the containerless floating method can be provided.

It is typical sectional drawing of the manufacturing apparatus of the glass material which concerns on 1st Embodiment. It is a schematic plan view of a part of the molding surface in the first embodiment. It is typical sectional drawing of the manufacturing apparatus of the glass material which concerns on 1st Embodiment. It is a schematic sectional drawing of the glass material manufactured in 1st Embodiment. It is typical sectional drawing of the manufacturing apparatus of the glass material which concerns on 2nd Embodiment.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described. A ratio of dimensions of an object drawn in a drawing may be different from a ratio of dimensions of an actual object. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

(First embodiment)
In this embodiment, a normal glass material, for example, a glass material that does not contain a network-forming oxide, and can be suitably manufactured even for a glass material having a composition that does not vitrify by a melting method using a container. Will be described. Specifically, according to the method of the present embodiment, for example, barium titanate glass material, lanthanum-niobium composite oxide glass material, lanthanum-niobium-aluminum composite oxide glass material, lanthanum-niobium-tantalum A composite oxide glass material, a lanthanum-tungsten composite oxide glass material, or the like can be suitably produced.

  FIG. 1 is a schematic cross-sectional view of a glass material manufacturing apparatus according to the first embodiment. As shown in FIG. 1, the glass material manufacturing apparatus 1 includes a mold 10. The molding die 10 has a molding surface 10a. The molding surface 10a is a curved surface. Specifically, the molding surface 10a has a spherical shape.

  The molding die 10 has a gas ejection hole 10b opened in the molding surface 10a. As shown in FIG. 2, in this embodiment, a plurality of gas ejection holes 10b are provided. Specifically, the plurality of gas ejection holes 10b are arranged radially from the center of the molding surface 10a.

  In addition, the shaping | molding die 10 may be comprised with the porous body which has an open cell. In that case, the gas ejection hole 10b is constituted by continuous bubbles.

  The gas ejection hole 10b is connected to a gas supply mechanism such as a gas cylinder. Gas is supplied from the gas supply mechanism to the molding surface 10a via the gas ejection hole 10b. The type of gas is not particularly limited. The gas may be, for example, air or oxygen, or an inert gas such as nitrogen gas, argon gas, or helium gas.

  When manufacturing a glass material using the manufacturing apparatus 1, first, the glass raw material lump 11 is arrange | positioned on the molding surface 10a. The glass raw material block 11 may be, for example, a glass material raw powder integrated by press molding or the like. The glass raw material block 11 may be, for example, a sintered body that is sintered after integrating the raw material powder of the glass material by press molding or the like. Moreover, the glass raw material lump 11 may be an aggregate of crystals having a composition equivalent to the target glass composition, for example.

  The shape of the glass raw material block 11 is not particularly limited. The glass raw material block 11 may be, for example, a lens shape, a spherical shape, a cylindrical shape, a polygonal column shape, a rectangular parallelepiped shape, an elliptical shape, or the like.

  Next, the glass raw material block 11 is floated on the molding surface 10a by ejecting gas from the gas ejection holes 10b. That is, the glass raw material block 11 is held in a state where the glass raw material block 11 is not in contact with the molding surface 10a. In this state, the glass material block 11 is irradiated with laser light from the laser irradiation device 12. Thereby, the glass raw material lump 11 is heated and melted to be vitrified to obtain molten glass. Then, the glass material 30 shown by FIG.3 and FIG.4 can be obtained by cooling a molten glass. In the step of heating and melting the glass raw material mass 11 and the step of cooling until the temperature of the molten glass and further the glass material becomes at least the softening point or less, at least gas ejection is continued, and the glass raw material mass 11 and the molten glass are heated. Or it is preferable to suppress that the glass material 30 and the molding surface 10a contact.

  In the present embodiment, an example in which the glass raw material mass 11 is heated by irradiating the glass raw material mass 11 with laser light has been described. However, in the present invention, the method of heating the glass raw material block 11 is not particularly limited to the method of irradiating laser light. For example, the glass raw material block 11 may be radiantly heated.

  The glass material 30 has a first surface 31 and a second surface 32. The first surface 31 faces the molding surface 10a during molding. The second surface 32 is located on the side opposite to the molding surface 10a during molding. Therefore, the second surface 32 is located on the side opposite to the first surface 31. The first surface 31 includes a central portion 31a and a peripheral edge portion 31b located outside the central portion 31a.

The curvature radius of the central portion 31a to _{R 1.} Note that the central portion 31a is not necessarily completely spherical. When the central portion 31a is not completely spherical, the radius of curvature of the central portion 31a means an equivalent radius of curvature.

Let R ₂ be the radius of curvature of the peripheral edge 31b. In addition, the peripheral part 31b does not necessarily need to be a spherical surface completely. When the peripheral edge 31b is not completely spherical, the radius of curvature of the peripheral edge 31b means an equivalent radius of curvature.

The radius of curvature of the second surface 32 and _{R 3.} Note that the second surface 32 is not necessarily completely spherical. When the second surface 32 is not completely spherical, the radius of curvature of the second surface 32 means an equivalent radius of curvature.

  Usually, in order to prevent a large temperature deviation from occurring in the molten glass or the glass material 30, it is considered that the flow rate of the gas ejected from the gas ejection hole 10b is lowered and the flow rate is reduced.

In contrast, in the present embodiment, the glass material 30 is manufactured while gas is ejected from the gas ejection holes 10b at a high flow rate and a large flow rate at which the glass material 30 satisfying R ₂ <R ₃ <R ₁ is formed. That is, the gas is blown from the gas ejection hole 10b at a high flow velocity and a large flow rate such that a portion having a smaller radius of curvature than the central portion of the first surface 31 and the second surface 32 is generated at the peripheral portion of the first surface 31. The glass material 30 is manufactured while ejecting. By doing in this way, the displacement at the time of the float of the glass raw material lump 11, molten glass, and the glass material 30 can be suppressed, and the glass raw material lump 11, the molten glass, and the glass material 30 can be stably floated. For this reason, the production | generation etc. of the crystal | crystallization by the contact with the glass raw material lump 11, molten glass and the glass material 30, and the shaping | molding surface 10a etc. can be suppressed. Therefore, the glass material 30 containing no crystals can be manufactured stably. That is, the glass material 30 satisfying R ₂ <R ₃ <R ₁ can be stably manufactured by the containerless floating method as in this embodiment.

From the viewpoint of producing the glass material 30 more stably, R ₃ is preferably 1.05 to ₃ times, more preferably 1.1 to 2.5 times R ₂ . R ₁ is preferably 1.01 to 25 times R ₃ and more preferably 1.1 to 12 times R ₃ . R ₁ is preferably 1.1 to 50 times R ₂ and more preferably 1.5 to 25 times.

  Hereinafter, other examples of preferred embodiments of the present invention will be described. In the following description, members having substantially the same functions as those of the first embodiment are referred to by the same reference numerals, and description thereof is omitted.

(Second Embodiment)
FIG. 5 is a schematic cross-sectional view of the glass material manufacturing apparatus 2 according to the second embodiment.

  In the first embodiment, the example in which the plurality of gas ejection holes 10b are opened on the molding surface 10a has been described. However, the present invention is not limited to this configuration. For example, like the glass material manufacturing apparatus 2 shown in FIG. 5, one gas ejection hole 10 b opened at the center of the molding surface 10 a may be provided. Even in this case, the glass material 30 can be stably manufactured as in the first embodiment.

  Hereinafter, the present invention will be described in more detail on the basis of specific examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented without departing from the scope of the present invention. Is possible.

Example 1
The raw material powder was weighed and mixed, and then melted at a temperature of about 1300 ° C. and cooled to prepare a crystal lump. A glass raw material lump was produced by cutting the crystal lump into a desired volume.

Next, the apparatus according to FIG. 1 was used, and the glass raw material lump was heated and melted by irradiating a carbon dioxide laser with an output of 100 W with the glass raw material lump floated above the molding surface under the following conditions. . Then, laser irradiation was stopped and the melt of the glass raw material lump was cooled. As a result, the diameter was 4.21 mm, R ₁ = 15.9 mm, R ₂ = 1.4 mm, R ₃ = 2.2 mm (R ₃ / R ₂ = 1.57, R ₁ / R ₃ = 7.23, A glass material of R ₁ / R ₂ = 11.4) was obtained.

Glass composition (molar ratio): 0.3 · La ₂ O ₃ -0.7 · Nb ₂ O ₅
Diameter of gas ejection hole: 0.3mm
Diameter of the molding surface in plan view: 14.7 mm
Number of gas ejection holes: 413 The portion with a diameter of 7.2 mm in the center of the molding surface is an arrangement structure in which adjacent gas ejection holes are arranged so as to be equally spaced from each other. The size of the angle formed by the arrangement direction of the ejection hole array is 11.25 °, and the distance between the centers of the gas ejection holes adjacent in the radial direction is 0.6 mm.

Area ratio occupied by gas ejection holes on molding surface: 17.2%
Gas flow rate: 8-15L / min
(Example 2)
After the raw material powder was weighed and mixed, the mixed powder was sintered by calcining at a temperature around 1500 ° C. The glass raw material lump was produced by cutting out from the sintered body to an amount of a desired volume.

Next, the apparatus according to FIG. 1 was used, and the glass raw material lump was heated and melted by irradiating a carbon dioxide laser with an output of 100 W with the glass raw material lump floated above the molding surface under the following conditions. . Then, laser irradiation was stopped and the melt of the glass raw material lump was cooled. As a result, the diameter was 6.17 mm, R ₁ = 12.7 mm, R ₂ = 1.8 mm, R ₃ = 3.3 mm (R ₃ / R ₂ = 1.83, R ₁ / R ₃ = 3.85, A glass material of R ₁ / R ₂ = 7.06) was obtained.

Glass composition (molar ratio): 0.3 · La ₂ O ₃ -0.7 · Al ₂ O ₃
Mold: Silicon carbide porous body Diameter in plan view of the molding surface: 8 mm
Center angle of molding surface: 52 °
Heating temperature: 2150 ° C
Gas flow rate: 6-13L / min
(Example 3)
A glass material was produced in the same manner as in Example 1 except that the following conditions were used. As a result, the diameter was 2.45 mm, R ₁ = 1.3 mm, R ₂ = 1.0 mm, R ₃ = 1.2 mm (R ₃ / R ₂ = 1.20, R ₁ / R ₃ = 1.08, R ₁ / R ₂ = 1.30) glass material was obtained.

Glass composition (molar ratio): 0.2 · La ₂ O ₃ -0.8 · WO ₃
Diameter of gas ejection hole: 0.1mm
Diameter of molding surface in plan view: 6 mm
Number of gas ejection holes: 185 Ratio of area occupied by gas ejection holes on the molding surface: 5.1%
Center angle of molding surface: 28 °
On the molding surface, the gas ejection holes were provided in a radial manner (the size of the angle formed by the arrangement direction of the gas ejection hole arrays: 22.5 °, the distance between the centers of the gas ejection holes adjacent in the radial direction: 0.2 mm).

Gas flow rate: 0.3 to 1.1 L / min
Example 4
After the raw material powder was weighed and mixed, the mixed powder was sintered by calcining at a temperature around 1000 ° C. The glass raw material lump was produced by cutting out from the sintered body to an amount of a desired volume.

Next, the apparatus according to FIG. 1 was used, and the glass raw material lump was heated and melted by irradiating a carbon dioxide laser with an output of 100 W with the glass raw material lump floated above the molding surface under the following conditions. . Then, laser irradiation was stopped and the melt of the glass raw material lump was cooled. As a result, a glass material having a diameter of 8.2 mm, R ₁ = 42.1 mm, R ₂ = 2.1 mm, R ₃ = 4.6 mm (R ₃ / R ₂ = 2.19, R ₁ / R ₃ = 9 .15, R ₁ / R ₂ = 20.0).

Glass composition (molar ratio): 0.33 · BaO−0.66 · TiO ₂
Diameter of gas ejection hole: 0.3mm
Diameter of the molding surface in plan view: 15 mm
Number of gas ejection holes: 253 Area ratio of gas ejection holes on the molding surface: 10.5%
Center angle of molding surface: 29 °
On the molding surface, the gas ejection holes were provided in a radial shape (the size of the angle formed by the arrangement direction of the gas ejection hole arrays: 11.25 °, the distance between the centers of the gas ejection holes adjacent in the radial direction: 0.6 mm).

  Gas flow rate: 7-14L / min

DESCRIPTION OF SYMBOLS 1, 2: Glass material manufacturing apparatus 10: Mold 10a: Molding surface 10b: Gas ejection hole 11: Glass raw material lump 12: Laser irradiation apparatus 30: Glass material 31: First surface 31a: Central part 31b: Peripheral part 32: Second surface

Claims (6)

In a state where the glass raw material lump is suspended and held above the molding surface by causing gas to be ejected from a gas ejection hole opened on the molding surface of the molding die, the glass raw material lump is heated and melted to be vitrified, After obtaining the molten glass, comprising a step of obtaining a glass material by cooling the molten glass,
The glass raw material lump is a press-molded body or sintered body of a raw material powder of a glass material, or an aggregate of crystals having a composition equivalent to a target glass composition,
The glass material has a first surface facing the molding surface and a second surface located on the opposite side of the molding surface;
The first surface includes a central portion and a peripheral portion located outside the central portion,
The radius of curvature of the central portion and R _1,
Let R ₂ be the radius of curvature of the peripheral edge,
The radius of curvature of the second surface when the R _3,
A method for producing a glass material, wherein gas is ejected from the gas ejection holes at a flow rate and a flow rate at which a glass material satisfying R ₂ <R ₃ <R ₁ is formed. The manufacturing method of the glass material of Claim 1 which heat-melts the said glass raw material lump by irradiation of a laser beam. The glass material is a barium titanate glass material, a lanthanum-niobium composite oxide glass material, a lanthanum-niobium-aluminum composite oxide glass material, a lanthanum-niobium-tantalum composite oxide glass material, or a lanthanum-tungsten composite. The manufacturing method of the glass material of Claim 1 or 2 which is an oxide type glass material. In a state where the glass raw material lump is suspended and held above the molding surface by causing gas to be ejected from a gas ejection hole opened on the molding surface of the molding die, the glass raw material lump is heated and melted to be vitrified, An apparatus for producing a glass material by cooling the molten glass after obtaining the molten glass,
The glass raw material lump is a press-molded body or sintered body of a raw material powder of a glass material, or an aggregate of crystals having a composition equivalent to a target glass composition,
The glass material has a first surface facing the molding surface and a second surface located on the opposite side of the molding surface;
The first surface includes a central portion and a peripheral portion located outside the central portion,
The radius of curvature of the central portion and R _1,
Let R ₂ be the radius of curvature of the peripheral edge,
The radius of curvature of the second surface when the R _3,
An apparatus for producing a glass material, wherein gas is ejected from the gas ejection holes at a flow rate and a flow rate at which a glass material satisfying R ₂ <R ₃ <R ₁ is formed. The manufacturing apparatus of the glass material of Claim 4 provided with the laser irradiation apparatus which irradiates a laser beam to the said glass raw material lump. The glass material is a barium titanate glass material, a lanthanum-niobium composite oxide glass material, a lanthanum-niobium-aluminum composite oxide glass material, a lanthanum-niobium-tantalum composite oxide glass material, or a lanthanum-tungsten composite. The manufacturing apparatus of the glass material of Claim 4 or 5 which is an oxide type glass material.

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