JP2022165547A - Multicomponent glass molding and method for manufacturing the same - Google Patents

Abstract

To provide a method that can manufacture a multicomponent glass molding of which flaws in a plasma resistant glass are reduced while improving production yield, and to provide a multicomponent glass molding of which flaws are reduced and which has excellent plasma resistance.SOLUTION: A method for manufacturing a multicomponent glass molding using a molding apparatus including a melting part, a mixing part and a molding part includes the steps of: (1) supplying mixed raw material powder of a multicomponent glass to the melting part, heating the supplied mixed raw material powder at a temperature or higher than a melting point of a mixed raw material powder composition and obtaining a melt precursor, where the heating temperature is lower than a temperature at which viscosity log η of the melt precursor is -0.5 Pa s; (2) heating the melt precursor to a temperature higher than that in the step (1) and obtaining melt; (3) supplying the melt to the molding part via the mixing part; and (4) cooling the melt supplied to the molding part and obtaining a multicomponent glass molding to which an internal shape of the molding part is reflected. The mixing part has a structure of mixing melt by causing the melt to pass therethrough. There is provided a multicomponent glass molding that meets a first grade or a second grade in bubble and foreign matter grades according to JOGIS.SELECTED DRAWING: Figure 1

Description

The present invention relates to multicomponent glass moldings and methods of making the same.

In order to improve productivity in semiconductor manufacturing processes, plasma-resistant multi-component glasses are used that are excellent in plasma resistance even in high-density plasma environments and less corroded even in repeated use. Multi-component glass is glass in which alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), or the like is added to quartz (SiO ₂ ). As methods for producing multi-component glasses, for example, an electric melting method, a plasma melting method, an oxyhydrogen flame melting method, and the like are known (Patent Documents 1 to 5).

In these methods, frit powder is melted to produce a glass ingot (lump) or the like. A glass ingot (lump) undergoes processing steps such as grinding and polishing to provide a multi-component glass product having a predetermined shape (Patent Documents 1 and 2). Depending on the shape of the multi-component glass product, a multi-component glass product can be obtained by melting the raw material powder in a mold of a predetermined shape and molding it into a predetermined shape (Patent Documents 3 and 4).

JP-A-2002-356337 JP-A-2002-356338 JP-A-2002-356345 Japanese Patent Application Laid-Open No. 2003-292337 JP-A-2004-284828

Patent Document 1 discloses a method of obtaining a glass ingot by melting a mixed powder as a raw material in a plasma flame. In this method, there is a problem that the mixed powder clogs the supply pipe during operation, resulting in unstable operation, generation of lamellar air bubbles, or contamination from bricks in the furnace. Although ingots can be produced by this method, it is difficult to directly produce moldings of complex shapes such as rings. Therefore, it is necessary to process the ingot into a molded product, and since a large amount of glass is ground and polished in the process, there is also the problem of low material yield.

Patent Document 2 discloses a method of obtaining a glass ingot by melting raw material powder using an oxyhydrogen burner. With this method, the resulting glass contains microbubbles (~φ0.5) and is difficult to remove. Moreover, as with the method described in Patent Document 1, it is difficult to manufacture a molded product having a complicated shape such as a ring shape, so there is also the problem of a low material yield.

Patent Documents 3 and 4 disclose a method of filling raw material powder in a carbon mold and melting it under reduced pressure in an electric furnace to obtain a glass ingot or molded product corresponding to the internal shape of the mold. However, there is no description of an example of manufacturing a molded article having a complicated shape such as a ring shape. When a multi-component glass was prepared by repeating the heat treatment conditions described in Patent Documents 3 and 4, the problem was that bubbles: ~φ0.3 (remaining local aggregated bubbles) and foreign matter: ~φ1 remained. became clear as

Patent Document 5 does not describe specific conditions of the manufacturing method.

In summary, the manufacturing methods described in Patent Documents 1 and 2 are not suitable from the viewpoint of quality and yield. In the production methods described in Patent Documents 3 and 4, the obtained multi-component glass has many bubbles and foreign matter, and there is a problem with the quality.

In recent years, plasma-resistant materials used in semiconductor manufacturing equipment have been required to be members with few defects in response to high-quality and thin-walled parts. In view of this background, it is an object of the present invention to provide a method for manufacturing multi-component glass moldings with reduced defects (bubbles and foreign matter) in the plasma-resistant glass while improving the product yield. A further object of the present invention is to provide a molded multi-component glass article having excellent plasma resistance, in which defects (bubbles and foreign matter) are reduced to an unprecedented level.

The present invention for solving the above problems is as follows.
[1]
A method for manufacturing a multi-component glass molded article using a molding apparatus having a melting section, a mixing section and a molding section, comprising:
(1) A molten precursor in which a raw mixed powder of a multi-component glass is supplied to a melting section, and the supplied raw mixed powder is heated at a temperature equal to or higher than the melting point of the raw mixed powder composition, and at least a part of the raw mixed powder is melted. the process of obtaining a body,
(2) a step of heating the obtained molten precursor to a temperature higher than that of step (1) to obtain a molten liquid;
(3) a step of supplying the melted liquid to the molding section through the mixing section; and (4) a process of cooling the melted liquid supplied to the molding section to obtain a molded multi-component glass product reflecting the internal shape of the molding section. including
The mixing part has a structure in which the melt is mixed as it flows,
The manufacturing method.
[2]
The multi-component glass contains silicon (Si), aluminum (Al), and one or more elements (M) selected from the group consisting of Group 2 elements, Group 3 elements and Group 4 elements of the periodic table. The manufacturing method according to [1], which is a multi-component glass that
[3]
The multi-component glass is a _three -component glass containing _{SiO2 , Al2O3} and _Y2O3 , the heating temperature in step (1) is 1350°C or higher, and the heating temperature in step (2) is 1600°C. ° C. or higher, the production method according to [1] or [2].
[4]
The production method according to any one of [1] to [3], wherein the temperature of the melt in steps (2) and (3) is a temperature equal to or higher than the temperature at which the viscosity log η of the melt is 1.5 Pa·s. .
[5]
The production according to any one of [1] to [4], wherein the temperature of the melt in steps (2) and (3) is a temperature at which the viscosity log η of the melt is −0.5 Pa s or lower. Method.
[6]
The manufacturing method according to any one of [1] to [5], wherein the molded multi-component glass product is tubular, columnar or flat.
[7]
A multi-component glass molded product in which the grades of air bubbles and foreign matter in the Japanese Optical Glass Standard are grades 1 and 2, respectively.
[8]
The molded multi-component glass product according to [7], which has a tubular, columnar or flat shape.
[9]
The multi-component glass is quartz (SiO ₂ ) The molded multi-component glass product according to [7] or [8], which is glass.

According to the present invention, excellent quality multi-component glass moldings with very few air bubbles and foreign matter can be produced. This multi-component glass molded product has excellent plasma resistance because it contains very few bubbles and foreign matter.

In the present invention, a molding apparatus having a three-chamber structure (melting chamber, mixing chamber, molding chamber) suitable for each process is used in the process of melting and molding the raw material mixed powder, and the melting conditions of the raw material mixed powder in the melting chamber are is controlled, the obtained melt is mixed in the mixing chamber to improve homogeneity, and by promoting degassing from the melt until it reaches the molding chamber, excellent quality with extremely few bubbles and foreign matter of multi-component glass moldings can be produced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side cross-section schematic explanatory drawing which shows one aspect|mode of the molding apparatus of this invention. FIG. 4 is a plan view of one embodiment of a plate with through holes for a mixing chamber; FIG. 2 is a plan view (top view) and a cross-sectional view (bottom view) of one embodiment of a plate having through holes for a mixing chamber. It is a side cross-sectional schematic explanatory drawing of the conventional shaping|molding die.

<Manufacturing method of multi-component glass molded product>
One aspect of the invention relates to a method of manufacturing a multicomponent glass molding using a molding apparatus having a melting section, a mixing section and a molding section. The production method of the present invention is
(1) A molten precursor in which a raw mixed powder of a multi-component glass is supplied to a melting section, and the supplied raw mixed powder is heated at a temperature equal to or higher than the melting point of the raw mixed powder composition, and at least a part of the raw mixed powder is melted. the process of obtaining a body,
(2) a step of heating the obtained molten precursor to a temperature higher than that of step (1) to obtain a molten liquid;
(3) a step of supplying the obtained melted liquid to the molding section through the mixing section; and (4) a multi-component glass molded article reflecting the internal shape of the molding section by cooling the molten liquid supplied to the molding section. including the step of obtaining
Further, the mixing section has a structure in which melts are mixed as they flow.

The molding apparatus used in the manufacturing method of the present invention has a dissolving section, a mixing section and a molding section. In this molding device,
The melting unit has a melting chamber for melting the supplied mixed raw material powder of the multi-component glass to obtain a molten liquid, and at least a part of the inner wall of the melting chamber is covered with a release material,
The mixing section has a structure in which the molten liquid is mixed as it flows,
The molding part has an internal shape at least partly corresponding to the external shape of the molded multicomponent glass, and is a mold for optionally defoaming the melt and then cooling to obtain the molded multicomponent glass. At least a portion of the inner wall of the molding chamber is covered with a release material.

The molding apparatus will be described below, and then the manufacturing method will be described.
FIG. 1 is a schematic side cross-sectional view showing one mode of the molding apparatus in FIG. 1 ; The planar shape of the molding apparatus shown in FIG. 1 is substantially circular. In the figure, 1 is a solid body, 2 is an upper lid, 3 is an outer cylinder, 4 is a release material, 5 is a bottom plate, 6 is a plate having through holes, and 7 is a spacer that determines the distance between the plates. The outer shape of the molding apparatus as a whole is composed of an outer cylindrical body 3 and a bottom plate 5, inside of which a release material 4 is provided to form the inner surface of the apparatus.

The melting section has a melting chamber 10 for melting the supplied mixed raw material powder of the multi-component glass. The melting chamber 10 has a cylindrical shape and has a bottom surface and an inner peripheral surface. Provided on parts that come into contact with the body and the melt. The bottom surface is the upper surface of the uppermost plate 6a that constitutes the mixing chamber 20 to be described later. The upper part of the melting chamber 10 is partly or wholly an opening for supplying raw materials, and the apparatus of FIG. 1 has an upper lid 2 at the opening. The melting chamber 10 is equipped with a heating device and a temperature sensor (not shown).

The mixing section has a mixing chamber 20 having a structure in which a melt obtained by melting the raw material mixed powder in the dissolving section flows and is mixed. The inside diameter of the mixing chamber 20 is substantially the same as the inside diameter of the melting chamber 10, and the inner peripheral surface of the mixing chamber 20 is covered with the release material 4, and the top plate 6a separates the melting chamber 10 and the mixing chamber 20 from each other. and are separated. In the mixing chamber 20, two or more layers of plates having single or multiple through holes are provided in the vertical direction. In the device of FIG. 1, three layers of plates 6a, 6b and 6c are provided, each with a spacer 7 between adjacent plates to determine the distance between the plates. A through-hole provided in one plate is installed in a positional relationship that does not substantially face a through-hole provided in an adjacent plate. By doing so, mixing is promoted when the melt flows through the mixing chamber 20 . The mixing chamber 20 can be equipped with a heating device and a temperature sensor (not shown). 2 and 3 show examples of planar shapes of plates having through holes.

The plate shown in FIG. 2 has a substantially disc shape with a diameter r1, and has one or more notches having a length L1 and a depth L2 on the outer peripheral edge. Diameter r1 corresponds to the inner diameter of mixing chamber 20 . This notch forms a through hole in the plate. When four notches are provided in one plate, if the length L1 of the notch is 1/8 or less of the total outer peripheral edge length of the plate, a plurality of plates are rotated, for example, every 45 ° to form a plurality of layers. As a result, the through-holes provided in one plate are positioned so as not to substantially face the through-holes provided in the other adjacent plate. Mixing of the melted liquid is promoted by flowing the melted liquid through the mixing chamber 20 in which the positional relationship of the cutouts of the plates is set in this manner. It has a structure of a so-called static mixer. The shape, size and number of cutouts to be provided can be appropriately determined in consideration of the viscosity of the melt, the number of plates to be placed in the mixing chamber 20, the homogeneity of the melt obtained by mixing, and the like. The number of notches provided in one plate is, for example, 1-10, preferably 2-8, more preferably 3-6.

The plate shown in FIG. 3 is substantially disk-shaped, and the diameter of the substantially disk-like shape corresponds to the inner diameter of the mixing chamber 20 . It has one or more substantially circular through-holes with a diameter r2 near the outer periphery. The plate of FIG. 3 has four through-holes, and the vertically adjacent plates 6a, 6b, 6c are rotated by 45°, and the four through-holes of the top plate 6a are shown in plan view. The holes are indicated by solid lines, and the through-holes in plate 6b underneath are indicated by dashed lines. The positional relationship between each plate and the through-holes is shown in cross sections AC and BD. By adjusting the diameter r2 of the through-hole provided in each plate, the through-hole provided in one plate can be provided at a position that does not substantially face the through-hole provided in the other adjacent plate. Mixing of the molten liquid is promoted by flowing the molten multi-component glass through the mixing chamber 20 provided with these plates. The number of through-holes, the size of the through-holes, and the number of through-holes to be provided can be appropriately determined in consideration of the viscosity of the melt, the number of plates installed in the mixing chamber 20, the homogeneity of the melt obtained by mixing, and the like. The number of through-holes provided in one plate is, for example, 1-10, preferably 2-8, more preferably 3-6.

The molding unit has a molding chamber 30 having an internal shape corresponding to the desired shape of the molded product, and the molding chamber 30 shown in FIG. It has an internal shape with a solid body for forming the hollow of the tubular molding. It has a bottom surface, an outer peripheral surface and an inner peripheral surface. The bottom surface, outer peripheral surface and inner peripheral surface are covered with a release material 4 . A release material covering the inner peripheral surface is fixed to the outer peripheral surface of the solid body 1 . At least a part of the upper portion of the molding chamber 30 is an open port, which is connected to the mixing chamber 20 . A through-hole (notch) of the bottom layer plate of the plate for the mixing section shown in FIG. It has a structure to allow the melt mixed at 20 to flow. Also in the case of the plate for the mixing section shown in FIG. It has a structure that allows the molten liquid to flow in. The molding chamber 30 includes a heating device and a temperature sensor (not shown).

The molding apparatus shown in FIG. 1 is a molding apparatus in which a dissolving section, a mixing section, and a molding section are integrated, but these may have different structures.

The manufacturing method will be described below.
Step (1)
(1) A molten precursor in which a raw mixed powder of a multi-component glass is supplied to a melting section, and the supplied raw mixed powder is heated at a temperature equal to or higher than the melting point of the raw mixed powder composition, and at least a part of the raw mixed powder is melted. get a body

Multi-component glasses are not particularly limited, and examples include silicon (Si) and aluminum (Al), Group 2 elements (alkaline earth metals), Group 3 elements (rare earths) and Group 4 elements of the periodic table in IUPAC format. and one or more elements (M) selected from the group consisting of group elements (titanium group), and multi-component quartz (SiO ₂ ) glass. Group 2 elements of the periodic table (alkaline earth metals) are, for example, Mg, Ca, Sr, and Ba; Group 3 elements (rare earths) are Sc, Y, La, etc.; Group 4 elements (titanium group) are Ti, Zr, Hf, and the like. The raw material of the multi-component glass can be a mixed powder having a desired composition, and can be oxides, carbonates, nitrates, chlorides, etc. of the above elements, and the powder raw material can be used as it is. . The composition of the mixed powder is also not particularly limited. However, from the viewpoint of obtaining a multi-component glass with high purity, it is preferable to use an oxide, and it is particularly preferable to use an oxide raw material with a low impurity content. Although there is no particular limitation on the particle size of the powder raw material, for example, powder with any particle size in the range of 0.1 to 1000 μm can be used.

A specific example of a multicomponent glass can be a _ternary glass containing _{SiO2 , Al2O3} and _Y2O3 . A mixed powder of these oxides can be used as a multi-component glass raw material, and the melting points of each oxide are 1710°C for SiO ₂ , 2072°C for Al ₂ O ₃ and 2425°C for Y ₂ O ₃ . However, the melting point of the three-component glass is about 1,300 to 1,500° C. depending on the composition, and there is a composition range in which transparent glass can be obtained (Journal of Japan Institute of Metals, Vol. 67, No. 1 (2003) 40-46, Fig. .2). In the present invention, in order to obtain a molded article of multicomponent glass, a composition range in which the above-mentioned transparent glass can be obtained and a composition range with a relatively low melting point is selected, and the mixed powder in the composition range is treated as a raw material mixed powder. A molten precursor is obtained in which at least a part of the mixed raw material powder is melted by heating at a temperature equal to or higher than the melting point of the composition. This heating causes at least a portion of the raw powder to react to form a molten precursor, which is the glass or glass precursor. However, for the purpose of suppressing the rapid reaction of the raw material powder and the generation of a large amount of foreign matter and bubbles in the glass, the heating temperature is less than the temperature at which the viscosity log η of the molten precursor becomes 1.5 Pa s. is preferably set to a temperature of The temperature at which the viscosity log η of the molten precursor becomes 1.5 Pa·s is determined by the composition of the raw material powder. In the case of the three-component glass, the reference temperature for this viscosity range is 1,350 to 1,600.degree. C., preferably 1,400 to 1,550.degree. By heating in this temperature range, it is possible to obtain a molten precursor having a viscosity log η of greater than 1.5 Pa·s while reacting the raw material mixed powder. From the viewpoint of suppressing the generation of bubbles due to unnecessary reaction between the release material and the glass raw material in the melting chamber, it is preferable to perform the step of forming the molten precursor before obtaining the molten liquid.

In the step (1), the raw material powders are thought to react with each other, bond with each other, and melt, entraining gas between the particles to form bubbles in the melt in the subsequent step. From the viewpoint of improving the foam quality by reducing the amount of foam to be defoamed by setting the heating temperature to a lower value, it is preferable to suppress the inclusion of foam during the reaction in step (1).

Step (2)
The molten precursor obtained in step (1) is heated to a temperature higher than in step (1) to obtain a molten liquid. The heating temperature should be at least the temperature at which the viscosity log η of the melt is 1.5 Pa s. is preferable from the viewpoint of facilitating More preferably, the heating temperature is equal to or higher than the temperature at which the viscosity log η of the melt is 0.5 Pa·s. If the viscosity of the dissolution liquid is too low, the flow speed will increase and mixing in the next step will become difficult. More preferably, the temperature is below the temperature at which the viscosity becomes -0.1 Pa·s. In the case of the three-component glass, the heating temperature can be, for example, in the range of 1550-1800.degree. C., preferably 1600-1750.degree.

Step (3)
The melt is supplied to the molding section through the mixing section. The mixing section has a structure in which the molten liquid is mixed as it flows, specifically, has a function of a so-called static mixer as described above, and is mixed and uniformed by flowing through the mixing section. The temperature of the melt can be the same as in step (2). The temperature range is preferably equal to or higher than the temperature at which the viscosity log η is 1.5 Pa·s. More preferably, the heating temperature is equal to or higher than the temperature at which the viscosity log η of the melt is 0.5 Pa·s. The time required for the molten liquid to be supplied from the melting section to the molding section via the mixing section varies depending on the amount of the molten liquid, the structure of the mixing section, the viscosity of the molten liquid, and the like. During the supply of the melt, degassing from the melt progresses and the foam quality can be improved, so the desired foam quality can be taken into consideration when determining the time until the supply is completed.

The molten liquid supplied to the molding section is sufficiently dissolved and has lower reactivity than the raw material powder. Therefore, even at high temperatures, the reaction with the release material that forms the inner wall of the molding chamber can be suppressed. , foam reduction and foreign matter contamination can be suppressed.

Step (4)
The melt supplied to the molding section is cooled to obtain a molded multi-component glass product reflecting the internal shape of the molding section. Cooling of the melt can be carried out by allowing the molding apparatus to cool while controlling the cooling rate. In the steps (2) and (3), it is preferable from the viewpoint of efficient degassing that the melted liquid is degassed, and that the melt supplied to the molding section is also degassed sequentially.

The production of glass moldings using the apparatus of the invention can be carried out either batchwise or continuously. In the case of the continuous type, it is also possible to continuously manufacture molded products of different shapes by using molding parts of different shapes and sizes with the same glass composition.

By using the apparatus and method of the present invention, it is possible to obtain a multi-component glass molded article having air bubbles and foreign matter of grade 1 or grade 2, respectively, according to the Japanese Optical Glass Standards. The present invention encompasses a multi-component glass molding in which the grades of air bubbles and foreign matter in the Japanese Optical Glass Standard are grades 1 and 2, respectively. The multi-component glass moldings of the present invention can be tubular, columnar or flat in shape. The multi-component glass constituting the multi-component glass molded article is selected from the group consisting of, for example, silicon (Si) and aluminum (Al), as well as Group 2 elements, Group 3 elements and Group 4 elements of the periodic table. It can be a multi-component glass containing one or more elements (M). The multicomponent glass that constitutes the multicomponent glass molding can be a _ternary glass containing _{SiO2 , Al2O3} and _Y2O3 . A ternary glass containing SiO ₂ , Al ₂ O ₃ and Y ₂ O ₃ has a composition range of, for example, 20-60 wt % SiO ₂ , 10-50 wt % Al ₂ O ₃ and 20-60 wt % Y ₂ O ₃ . It can be glass, and preferably has a composition range of SiO ₂ : 27.5 to 43.3 wt%, Al ₂ O ₃ : 18.3 to 32.5 wt%, Y ₂ O ₃ : 25 to 45 wt%. (Reference: Journal of Japan Institute of Metals, Vol. 67, No. 1 (2003) 40-46).

Hereinafter, the present invention will be described in more detail based on examples. However, the examples are illustrative of the present invention, and the present invention is not intended to be limited to the examples.

1) Preparation of mixed powder A mixed powder was prepared by the method shown below using the following raw materials.
(i) raw material powder SiO ₂ : silica powder (purity of 99.9% or more),
- Al ₂ O ₃ : alumina powder (purity of 99.9% or more),
- Y ₂ O ₃ : yttria powder (99.9% or higher purity),
( _ii ) Preparation _SiO2 : 40 wt%, _Al2O3 : ₃₀ wt%, _Y2O3 : 30 wt%. Feed 0.5-3 kg and mix on a rotating platform.

2) Molding mold and melting of mixed powder of powder Example 1
Using the molding apparatus shown in FIG. 1, pipe-shaped multi-component glass moldings having sizes shown in Table 2 were prepared. The melting chamber was filled with 0.67 kg of the mixed powder prepared in 1) above, and melted in a high-temperature furnace at 1400° C. for 4 hours. Next, the temperature was raised to 1650° C., and after 2 hours, a melt was formed, and the melt flowed down by its own weight into the molding chamber via the mixing chamber. At that time, the temperatures of the melting chamber, the mixing chamber and the molding chamber were set to 1650° C. to defoam residual bubbles in the melt. It took 30 minutes for the melt to flow down into the molding chamber, after which the entire molding apparatus was allowed to cool, and after reaching room temperature, the molded product was removed from the molding chamber.

The viscosities of the molten precursor and the molten liquid obtained by heating the mixed powder having the above composition are as follows: 1,450°C: log η = 1.25 Pa s; 1650° C.: log η=−0.8 Pa·s, which is a condition that allows flow at 1,450° C. or higher. In the above example, the heating temperature is set to 1,400° C. and the raw material powder is changed into the molten precursor in the melting chamber. The viscosity of the molten precursor at this time is log η=−0.15 Pa·s. After that, the temperature was raised to 1,650° C. to obtain a melt having log η=−0.5 Pa·s, and then the melt was transferred from the melting chamber to the molding chamber via the mixing chamber. Degassing progressed from the melting chamber through the mixing chamber to the molding chamber and in the molding chamber from the melt having the viscosity described above.

Example 2
A molded product was prepared in the same manner as in Example 1, except that the mixed powder amount was 36 kg, and the temperature was raised to 1650° C. and then 3 hours passed.

Comparative example 1
Using the prior art mold shown in FIG. 4 and having a shape corresponding to the molding chamber of the molding apparatus shown in FIG. was prepared. The molding die has a single-chamber structure, and powder melting, defoaming and molding are performed in the same chamber. 670 g of the mixed powder prepared in 1) above was filled and dissolved at 1400° C. for 4 hours. Next, the temperature was raised to 1650° C. for 2 hours to remove air bubbles remaining in the melt.

3) Quality of molded product <evaluation method>
The outer surface of the molded product taken out from the mold is ground or sliced, and the cut surface is ground. Since the processed evaluation sample is a ground surface, a pseudo-liquid with the same refractive index is applied and observed according to the method for measuring bubbles in optical glass and the method for measuring foreign matter in optical glass specified by the Japan Optical Glass Industry Association. evaluated.
Table 1 shows the Japanese Optical Glass Industrial Standards.

<Quality of molded product>
Table 2 shows the quality of the molded products obtained in Examples 1 and 2 and Comparative Example 1.
Bubbles and foreign matter in the molded articles of Examples 1 and 2 were grade 1 of the Japanese Optical Glass Standard. The molded product of Comparative Example 1 using the mold of the prior art had a quality of 3 and 4 in terms of bubbles and foreign matter, which was not satisfactory.

It is useful in fields related to the manufacture of multi-component glass moldings.

Claims (9)

A method for manufacturing a multi-component glass molded article using a molding apparatus having a melting section, a mixing section and a molding section, comprising:
(1) A molten precursor in which a raw mixed powder of a multi-component glass is supplied to a melting section, and the supplied raw mixed powder is heated at a temperature equal to or higher than the melting point of the raw mixed powder composition, and at least a part of the raw mixed powder is melted. the process of obtaining a body,
(2) a step of heating the obtained molten precursor to a temperature higher than that of step (1) to obtain a molten liquid;
(3) a step of supplying the melted liquid to the molding section through the mixing section; and (4) a process of cooling the melted liquid supplied to the molding section to obtain a molded multi-component glass product reflecting the internal shape of the molding section. including
The mixing part has a structure in which the melt is mixed as it flows,
The manufacturing method. The multi-component glass contains silicon (Si), aluminum (Al), and one or more elements (M) selected from the group consisting of Group 2 elements, Group 3 elements and Group 4 elements of the periodic table. The manufacturing method according to claim 1, which is a multicomponent glass that The multi-component glass is a _three -component glass containing _{SiO2 , Al2O3} and _Y2O3 , the heating temperature in step (1) is 1350°C or higher, and the heating temperature in step (2) is 1600°C. 3. The production method according to claim 1 or 2, wherein the temperature is at or above °C. The temperature of the melt in steps (2) and (3) is Pa s, which is a temperature equal to or higher than the temperature at which the viscosity log η of the melt is 1.5 Pa s, and the production according to any one of claims 1 to 3. Method. The production method according to any one of claims 1 to 4, wherein the temperature of the melt in steps (2) and (3) is a temperature below the temperature at which the viscosity logη of the melt is -0.5 Pa·s. 6. The manufacturing method according to any one of claims 1 to 5, wherein the multicomponent glass molding is tubular, columnar or flat. A multi-component glass molded product in which the grades of air bubbles and foreign matter in the Japanese Optical Glass Standard are grades 1 and 2, respectively. 8. The multi-component glass molding of claim 7, which is tubular, columnar or tabular in shape. The multi-component glass contains silicon (Si), aluminum (Al), and one or more elements (M) selected from the group consisting of Group 2 elements, Group 3 elements and Group 4 elements of the periodic table. 9. The multi-component glass molded article according to claim 7 or 8, which is a multi-component glass.

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