JP6610405B2 - Manufacturing method of glass material - Google Patents

Description

  The present invention relates to a method for producing a glass material by a containerless floating method.

  In recent years, research on a containerless floating method has been made as a method for producing glass materials. 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.

  In the method disclosed in Patent Document 1, a laser beam is irradiated from above and below the glass raw material lump and heated and melted in a state where the glass raw material lump is suspended by jetting gas from a gas floating furnace. Therefore, it is considered that the laser beam irradiated from below is emitted through the gas ejection hole of the gas floating furnace.

JP 2006-248801 A

  However, when the glass material lump is irradiated with a laser beam from above and below and heated to melt, the composition of the obtained glass material may become inhomogeneous.

  The objective of this invention is providing the manufacturing method of a glass material which can homogenize a composition even if a laser beam is irradiated from the up-down direction of a glass raw material lump.

  A method for producing a glass material according to the present invention is a method for producing a glass material by cooling after heating and melting in a state where a glass raw material lump is suspended, and the glass is produced by jetting gas from below to above In the step of irradiating the laser beam, the step of suspending the raw material lump and the step of irradiating the glass raw material lump with the laser beam from below and above with the glass raw material lump suspended. After the raw material lump is heated and melted and the glass raw material lump is completely melted by the heat melting to become a molten glass lump, the output of the laser beam irradiated from below becomes higher than the output of the laser beam irradiated from above It is characterized by adjusting as follows.

  In the present invention, it is preferable to maintain a state in which the output of the laser beam irradiated from below is higher than the output of the laser beam irradiated from above until cooling.

  In this invention, it is preferable to adjust so that the output until the said glass raw material lump of the laser beam irradiated from the said upper side becomes more than the output after melt | dissolving completely.

In the present invention, the output of the laser beam irradiated from the lower side may be adjusted so that the viscosity of the molten glass lump in the irradiated portion of the laser beam irradiated from the lower side is 10 ⁻³ Pa · s or more. preferable.

  In the present invention, as the glass raw material block, for example, one containing boric acid is used.

  ADVANTAGE OF THE INVENTION According to this invention, even if it irradiates a laser beam from the up-down direction of a glass raw material lump, the manufacturing method of the glass material which does not become heterogeneous easily and can homogenize a composition can be provided.

It is typical sectional drawing which shows the glass material manufacturing apparatus used with the manufacturing method of the glass material which concerns on the 1st Embodiment of this invention. It is a figure which shows the relationship between the output of the 1st and 2nd laser beam, and time in the manufacturing method of the 1st Embodiment of this invention. In the manufacturing method of the glass material which concerns on the 1st Embodiment of this invention, it is a schematic diagram which shows the laser irradiation part of the glass raw material lump (molten glass lump) which became a melt by irradiating a laser beam. In the manufacturing method of the glass material which concerns on the 1st Embodiment of this invention, it is a schematic diagram which shows the state until a glass raw material lump melt | dissolves completely. It is a figure which shows the relationship between the output of the 1st and 2nd laser beam, and time in the manufacturing method of the glass material which concerns on the 2nd Embodiment of this invention. It is a figure which shows the relationship between the output of the 1st and 2nd laser beam, and time in the manufacturing method of the glass material which concerns on the 3rd Embodiment of this invention. It is typical sectional drawing which shows the glass material manufacturing apparatus used with the manufacturing method of the glass material which concerns on the 4th Embodiment of this invention. It is typical sectional drawing which shows the glass material manufacturing apparatus used with the manufacturing method of the glass material which concerns on the 5th Embodiment of this invention.

  Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing a glass material manufacturing apparatus used in the glass material manufacturing method according to the first embodiment of the present invention.

  As shown in FIG. 1, in the glass material manufacturing apparatus 1, the glass raw material block 2 is arranged in a floating state above the molding surface 10 a of the molding member 10. One hole 3 through which the gas 4 is ejected from below to above is formed at the center of the molding surface 10a. When the gas 4 is ejected from the hole 3, the glass raw material block 2 is floating upward. When the gas 4 is supplied to the hole 3 from a gas supply means such as a gas cylinder, the gas 4 is ejected from the hole 3.

  The type of the gas 4 is not particularly limited, and may be, for example, air, oxygen, an inert gas such as nitrogen gas, argon gas, helium gas, or carbon monoxide gas. It may be a reducing gas containing carbon dioxide gas or hydrogen.

  Moreover, the shaping | molding member 10 can be comprised by silicon carbide, a super steel, stainless steel, aluminum, duralumin, carbon, etc., for example.

  In the manufacturing method of the first embodiment, as shown in FIG. 1, the glass raw material block 2 is floated by ejecting a gas 4 from the hole 3, and the first laser light source 5 as a heating unit is suspended. The first laser beam 6 passes through the hole 3 and irradiates the glass raw material block 2 from below. Moreover, the 2nd laser light source 7 which is a heating means is also provided above the glass raw material lump 2, and the 2nd laser beam 8 from the 2nd laser light source 7 is also irradiated to the glass raw material lump 2 from the upper part. By irradiating the first and second laser beams 6 and 8, the glass raw material block 2 is heated and melted to form a molten glass block, and then cooled to obtain a glass material. In the step of heating and melting the glass raw material lump 2 and the step of cooling until the temperature of the glass material is at least equal to or lower than the softening point, at least the gas 4 is continuously ejected, and the glass raw material lump 2, the molten glass lump, or the glass It is preferable to prevent the material from contacting the molding surface 10a.

  The manufacturing method of the first embodiment is characterized by adjusting the output of the first laser beam 6 (laser beam irradiated from below) and the output of the second laser beam 8 (laser beam irradiated from above). It is in. A method for adjusting the first and second laser beams 6 and 8 in the first embodiment will be described below with reference to FIG.

  FIG. 2 is a diagram showing the relationship between the output of the first and second laser beams and time in the manufacturing method of the first embodiment. In FIG. 2, the output of the first laser beam 6 is indicated by a solid line, and the output of the second laser beam 8 is indicated by a one-dot chain line.

  In the manufacturing method of the first embodiment, first, the output of the first and second laser beams 6 and 8 is increased as shown in FIG. Subsequently, when the target output is reached, the output is maintained for a certain period of time, and the glass raw material block 2 is completely melted to form a molten glass block (time t in FIG. 2). Next, while maintaining the output of the first laser beam 6 as it is, the output of the second laser beam 8 is lowered to the target output. Subsequently, the outputs of the first and second laser beams 6 and 8 are held for a predetermined time, and then the irradiation of the first and second laser beams 6 and 8 is stopped. Finally, the molten glass lump is cooled to obtain a glass material. In the present invention, “completely melted” means a state in which there is no undissolved material of the glass raw material lump 2 in the molten glass lump.

  Thus, in the manufacturing method of the first embodiment, after the glass raw material block 2 is completely melted by heat melting, the output of the first laser beam 6 irradiated from below is the second laser irradiated from above. Adjustment is made to be higher than the output of the beam 8. Therefore, compositional heterogeneity hardly occurs in the obtained glass material. The reason for this can be explained as follows with reference to FIG.

  FIG. 3 is a schematic diagram showing a laser irradiation portion of a glass raw material lump (molten glass lump) that has become a melt by being irradiated with a laser beam. In the comparative example, after the glass raw material block 2 is completely melted to become a molten glass block, the first and second laser beams 6 and 8 are adjusted to the same output. At this time, since the gas 4 is blown onto the irradiation portion 11 of the first laser beam 6 irradiated from below, the temperature becomes lower than that of the irradiation portion 12 of the second laser beam 8 irradiated from above. For this reason, the evaporation amount of the molten glass block in the irradiated portion 11 of the lower first laser beam 6 is smaller than the evaporated amount of the molten glass block in the irradiated portion 12 of the upper second laser beam 8. As a result, the glass composition will be different above and below the resulting glass material. In particular, when the temperature of the irradiated portion 12 irradiated from above is higher than the temperature of the irradiated portion 11 below, convection hardly occurs in the molten glass lump, and the composition difference remains as it is. The composition becomes inhomogeneous.

  On the other hand, in this embodiment, after the glass raw material lump 2 is completely melted to become a molten glass lump, the output of the first laser beam 6 is higher than the output of the second laser beam 8. It is adjusted. Therefore, the temperature of the irradiated portion 11 of the first laser beam 6 shown in FIG. 3 can be made equal to or higher than the temperature of the irradiated portion 12 of the second laser beam 8. When the temperature of the irradiated portion 11 of the first laser beam 6 is the same as the temperature of the irradiated portion 12 of the second laser beam 8, the amount of evaporation is the same above and below the molten glass lump, so that the composition is inhomogeneous. Is unlikely to occur. On the other hand, when the temperature of the irradiated portion 11 of the first laser beam 6 is higher than the temperature of the irradiated portion 12 of the second laser beam 8, the upper and lower portions of the molten glass lump are mixed by convection and the temperature becomes uniform as a whole. . Therefore, even in this case, the entire melt of the molten glass lump becomes uniform, and the composition of the obtained glass material becomes uniform.

  Therefore, by adjusting the output of the first laser beam 6 irradiated from below to be higher than the output of the second laser beam 8 irradiated from above, compositional inhomogeneity is hardly generated in the obtained glass material. can do. In addition, in the manufacturing method of 1st Embodiment, after the glass raw material lump 2 is melt | dissolved completely by heat melting, it adjusts so that the output of the 1st laser beam 6 may become high, You may adjust so that the output of the 1st laser beam 6 may become high after hold | maintaining an output for a fixed time.

  In the present embodiment, the state in which the output of the first laser beam 6 is adjusted to be higher than the output of the second laser beam 8 is maintained until cooling. For this reason, it is possible to further reduce the occurrence of compositional inhomogeneity in the obtained glass material. However, in the present invention, after the glass raw material block 2 is completely melted to become molten glass, the output of the first laser beam 6 is adjusted to be higher than the output of the second laser beam 8. It suffices if the time is constant.

  Further, in the present embodiment, the output until the glass raw material block 2 of the second laser beam 8 irradiated from above is completely melted is adjusted to be equal to or higher than the output after completely melting. In this case, as shown in FIG. 4, the upper melting portion 13 can easily flow downward, so that the glass raw material block 2 can be melted more easily. In the present invention, the output until the second laser beam 8 irradiated from above is completely melted may be adjusted to be lower than the output after completely melting. However, in this case, the viscosity of the upper portion is increased, and thus the glass raw material block 2 may not be completely melted.

In the present invention, the output of the first laser beam 6 is adjusted so that the viscosity of the molten glass lump in the irradiated portion 11 of the first laser beam 6 shown in FIG. 3 is 10 ⁻³ Pa · s or more. It is preferable. If the viscosity of the irradiated portion 11 is too low, the molten glass lump may be scattered or dented by the gas 4, and the floating of the molten glass lump may become unstable.

From the viewpoint of further stabilizing the floating of the molten glass lump, the viscosity of the molten glass lump in the irradiated portion 11 is more preferably 10 ⁻² Pa · s or more, and further preferably 10 ⁻¹ Pa · s or more. Further, from the viewpoint of further homogenizing the molten glass lump and making the composition non-homogeneous more difficult, the viscosity of the molten glass lump in the irradiated portion 11 is preferably 10 ³ Pa · s or less, more preferably 10 ² Pa. · S or less, more preferably 10 ¹ Pa · s or less.

  In the present invention, the gas 4 may be used after being heated. In this case, since the irradiated portion 11 of the first laser beam 6 is more difficult to cool, the compositional inhomogeneity in the glass material can be further reduced.

  Although it does not specifically limit as the glass raw material lump 2, When it contains the component which is easy to evaporate, it is easy to enjoy the effect of this invention. Examples of such components include boric acid, silica, and phosphorus. In particular, boric acid is easy to evaporate. Therefore, when producing a glass material containing boric acid, it is particularly easy to enjoy the effects of the present invention. Even if the glass raw material block 2 contains such a component, according to the production method of the present invention, it is possible to further reduce the occurrence of compositional heterogeneity in the obtained glass material.

(Second Embodiment)
FIG. 5 is a diagram showing the relationship between the output of the first and second laser beams and the time in the manufacturing method of the second embodiment. In FIG. 5, the output of the first laser beam 6 is indicated by a solid line, and the output of the second laser beam 8 is indicated by a one-dot chain line.

  As shown in FIG. 5, in the second embodiment, the outputs of the first and second laser beams 6 and 8 are increased so that the output of the second laser beam 8 is higher. Subsequently, when the target output is reached, the output is maintained for a certain time, and the glass raw material block 2 is completely melted to form a molten glass block (time t in FIG. 5). Although the outputs of the first and second laser beams 6 and 8 are simultaneously increased in FIG. 5, for example, only the output of the second laser beam 8 is increased at first, and the first laser is emitted after a certain time has elapsed. The output of the beam 6 may be increased. Next, the output of the first laser beam 6 is increased, and the output of the second laser beam 8 is decreased to adjust the output of the first laser beam 6 to be higher. Subsequently, the outputs of the first and second laser beams 6 and 8 are held for a predetermined time, and then the irradiation of the first and second laser beams 6 and 8 is stopped. Finally, the molten glass lump is cooled to obtain a glass material. Other points are the same as in the first embodiment.

  Also in the manufacturing method of the second embodiment, after the glass raw material lump 2 is completely melted by heating and melting to become a molten glass lump, the output of the first laser beam 6 irradiated from below is irradiated from above. The output is adjusted to be higher than the output of the second laser beam 8. Therefore, compositional heterogeneity hardly occurs in the obtained glass material.

(Third embodiment)
FIG. 6 is a diagram showing the relationship between the output of the first and second laser beams and time in the manufacturing method of the third embodiment. In FIG. 6, the output of the first laser beam 6 is indicated by a solid line, and the output of the second laser beam 8 is indicated by an alternate long and short dash line.

  As shown in FIG. 6, also in the third embodiment, the outputs of the first and second laser beams 6 and 8 are increased so that the output of the second laser beam 8 is higher. Subsequently, when the target output is reached, the output is held for a certain time, and the glass raw material block 2 is completely melted to form a molten glass block (time t in FIG. 6). Next, both the outputs of the first laser beam 6 and the second laser beam 8 are lowered. Here, the lowering speed of the output of the second laser beam 8 is increased, and the output of the first laser beam 6 is adjusted to be higher than the output of the second laser beam 8. Subsequently, the outputs of the first and second laser beams 6 and 8 are held for a certain period of time, and then the irradiation of the first and second laser beams 6 and 8 is stopped. Finally, the molten glass lump is cooled to obtain a glass material. Other points are the same as in the first embodiment.

  Also in the manufacturing method of the third embodiment, after the glass raw material lump 2 is completely melted by heating and melting to become a molten glass lump, the output of the first laser beam 6 irradiated from below is irradiated from above. The output is adjusted to be higher than the output of the second laser beam 8. Therefore, compositional heterogeneity hardly occurs in the obtained glass material.

(Fourth embodiment)
FIG. 7: is typical sectional drawing which shows the glass material manufacturing apparatus used with the manufacturing method of the glass material which concerns on the 4th Embodiment of this invention.

  As shown in FIG. 7, in the glass material manufacturing apparatus 21, the glass raw material block 2 is arranged in a floating state above the molding surface 10 a of the molding member 10. The molding surface 10a is preferably provided in a concave spherical shape or a concave aspherical shape. First and second holes 3a and 3b for ejecting the gas 4 from below to above are formed at the center of the molding surface 10a. When the gas 4 is ejected from the first and second holes 3a and 3b, the glass raw material block 2 floats upward. When the gas 4 is supplied to the first and second holes 3a and 3b from a gas supply means such as a gas cylinder, the gas 4 is ejected from the first and second holes 3a and 3b.

  The second hole 3b is formed in the central portion of the molding surface 10a of the molding member 10, and a plurality of the first holes 3a are formed outside the second hole 3b. The first and second holes 3a and 3b are formed to have substantially the same hole diameter.

  As shown in FIG. 7, in a state where the glass raw material block 2 is floated by ejecting the gas 4 from the first and second holes 3a, 3b, the first laser light source 5 is heated from the first laser light source 5. The laser beam 6 is passed through the second hole 3b to irradiate the glass raw material block 2. In the present embodiment, the second laser light source 7 serving as a heating means is also provided above the glass raw material block 2, and the second laser beam 8 from the second laser light source 7 is also formed on the glass raw material member 2. Irradiate. By irradiating the first and second laser beams 6 and 8, the glass raw material block 2 is heated and melted to form a molten glass block, and then cooled to obtain a glass material. Other points are the same as in the first embodiment.

  In the fourth embodiment, since the plurality of first holes 3a through which the gas 4 is ejected are provided, the floating state of the glass raw material lump 2 and the molten glass lump can be kept more stable.

  Also in the manufacturing method of the fourth embodiment, after the glass raw material block 2 is completely melted by heating and melting to form a molten glass block, the output of the first laser beam 6 irradiated from below is from above. The output is adjusted to be higher than the output of the second laser beam 8 to be irradiated. Therefore, compositional heterogeneity hardly occurs in the obtained glass material.

(Fifth embodiment)
FIG. 8: is typical sectional drawing which shows the glass material manufacturing apparatus used with the manufacturing method of the glass material which concerns on the 5th Embodiment of this invention.

  In the glass material manufacturing apparatus 31, the molding member 10 is made of a porous material having communication holes. As shown in FIG. 8, the molding member 10 is held by a holding member 14 provided around the molding member 10. Further, by providing the holding member 14, the gas 4 passes through the communication hole of the molding member 10 and is shielded from leaking from the side of the molding member 10. A second hole 3b is formed at the center of the molding surface 10a.

  In the present embodiment, the communication hole of the molding member 10 existing around the second hole 3b constitutes the first hole 3a. The communication hole constituting the first hole 3 a is a hole that continues from the lower side to the upper side of the molding member 10. The gas 4 supplied to the lower side of the molding member 10 passes through this communication hole and is ejected above the molding surface 10a. Further, the gas 4 supplied below the molding member 10 is also ejected above the molding surface 10a by passing through the second hole 3b.

  As a porous material constituting the molded member 10, a porous ceramic material such as a carbide such as silicon carbide, a nitride, or an oxide can be used.

  In this embodiment, since the communicating hole of the porous material is the first hole 3a, the first hole 3a is provided in a large number. For this reason, the floating state of the glass raw material lump 2 or the molten glass lump can be stably maintained by the gas 4 ejected from the first hole 3a. Moreover, since many 1st holes 3a are provided around the 2nd hole 3b, the floating state of the glass raw material lump 2 or a molten glass lump can be kept more stable. Note that the plurality of formed first holes 3a do not necessarily have the same diameter, and may be different from each other. Other points are the same as in the first embodiment.

  Also in the manufacturing method of the fifth embodiment, after the glass raw material lump 2 is completely melted by heating and melting into a molten glass lump, the output of the first laser beam 6 irradiated from below is irradiated from above. The output is adjusted to be higher than the output of the second laser beam 8. Therefore, compositional heterogeneity hardly occurs in the obtained glass material.

  According to the present invention, since a glass material can be produced by a containerless floating method, a glass material that does not vitrify by a melting method using a container so as not to contain a network-forming oxide is used. Can be manufactured. Examples of such glasses include terbium-boric acid complex oxide glass materials, lanthanum-tantalum-boric acid glass materials, lanthanum-niobium complex oxide glass materials, and lanthanum-niobium-aluminum complex oxide glass materials. Examples thereof include lanthanum-niobium-tantalum composite oxide glass materials, lanthanum-tungsten composite oxide glass materials, lanthanum-titanium composite oxide glass materials, and lanthanum-titanium-zirconia composite oxide glass materials. In particular, when producing a lanthanum-tantalum-borate glass material containing boric acid that easily evaporates during heating and melting of the glass raw material mass 2, it is easy to enjoy the effects of the present invention.

  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 calcined at a temperature of about 1000 ° C. to sinter the raw material powder. A desired amount was cut out from the sintered body to produce a glass raw material block 2. Glass composition of the glass raw material mass 2 is 53 _mol% La ₂ O 3 -10 _mol% Ta ₂ O 5 -37 _mole% B 2 _{O 3.}

  Next, using the glass material manufacturing apparatus 1 according to the first embodiment shown in FIG. 1, the glass material lump 2 was heated and melted under the following conditions to produce a glass material. The specific procedure is shown below.

  First, 0.15 g of the glass raw material block 2 was placed on the molding surface 10 a of the molding member 10. Next, nitrogen gas as the gas 4 was supplied to the hole 3 from the gas supply means, and the glass raw material block 2 was suspended above the molding surface 10a. In this state, the glass material block 2 is irradiated with the first laser beam 6 through the hole 3 from the lower first laser light source 5 and the second laser beam from the upper second laser light source 7. 8 was irradiated to the glass raw material block 2. Each of the first and second laser beams 6 and 8 increases the output at 2 W / second, and when the output reaches 20 W (total 40 W), the output is maintained for 5 seconds to completely complete the glass raw material block 2. To melt. In addition, the temperature of the glass raw material lump 2 (molten glass lump) when completely melted was 1550 ° C. After completely melting, the output of the lower first laser beam 6 was set to 30 W, the output of the upper second laser beam 8 was set to 10 W, the output was maintained for 30 seconds, and then the laser irradiation was stopped.

  Thereafter, the glass material lump 2 was cooled to obtain a flat glass material. The obtained glass material had a diameter of 2.7 mm and was confirmed to be homogeneous by observation with a stereomicroscope.

(Example 2)
Using the glass raw material lump 2 prepared in the same manner as in Example 1, using the glass material manufacturing apparatus 21 according to the fourth embodiment shown in FIG. 7, the glass raw material lump 2 is heated and melted under the following conditions. Thus, a glass material was produced. The specific procedure is shown below. In Example 2, the glass material manufacturing apparatus 21 in which the number of the first holes 3a is 253 and the number of the second holes 3b is one was used.

  First, 0.32 g of the glass raw material block 2 was placed on the molding surface 10 a of the molding member 10. Next, nitrogen gas was supplied as the gas 4 from the gas supply means to the first hole 3a and the second hole 3b, and the glass raw material block 2 was suspended above the molding surface 10a. In this state, the glass material block 2 is irradiated with the first laser beam 6 through the second hole 3b from the lower first laser light source 5 and the second laser light source 7 from the upper second laser light source 7 is irradiated. The glass raw material block 2 was irradiated with the laser beam 8. The output of the first laser beam 6 is increased by 1 W / sec and the second laser beam 8 is increased by 2 W / sec, the output of the first laser beam 6 is 25 W, and the output of the second laser beam 8 is 50 W. At that time, the glass raw material block 2 was completely melted by maintaining the output for 3 seconds. In addition, the temperature of the glass raw material lump 2 (molten glass lump) when completely melted was 1550 ° C. After complete melting, the output of the lower first laser beam 6 was set to 50 W, the output of the upper second laser beam 8 was set to 20 W, the output was maintained for 30 seconds, and then the laser irradiation was stopped.

  Thereafter, the glass material lump 2 was cooled to obtain a flat glass material. The obtained glass material had a diameter of 5.1 mm and was confirmed to be homogeneous by observation with a stereomicroscope.

Example 3
Using the glass raw material lump 2 prepared in the same manner as in Example 1, using the glass material manufacturing apparatus 31 according to the fifth embodiment shown in FIG. 8, the glass raw material lump 2 is heated and melted under the following conditions. Thus, a glass material was produced. The specific procedure is shown below.

  First, 0.25 g of the glass raw material block 2 was placed on the molding surface 10 a of the molding member 10. As the molded member 10, a silicon carbide porous body (pore diameter of communication holes of 5 to 50 μm, porosity of 40%) was used. Next, nitrogen gas was supplied as the gas 4 from the gas supply means to the molding member 10 in which the first hole 3a and the second hole 3b were formed, and the glass raw material block 2 was suspended above the molding surface 10a. In this state, the glass raw material block 2 was irradiated with the second laser beam 8 from the upper second laser light source 7. The output of the second laser beam 8 was increased at 1 W / second, and when the output of the second laser beam 8 reached 70 W, the output was held for 5 seconds to completely melt the glass raw material block 2. . In addition, the temperature of the glass raw material lump 2 (molten glass lump) when completely melted was 1550 ° C. After complete melting, the output of the second laser beam 8 was lowered at 10 W / sec, and the output of the second laser beam 8 was set to 0 W. Further, from one second before starting to lower the output of the second laser beam 8, the first laser light source 5 below passes through the second hole 3b to irradiate the glass raw material block 2 with the first laser beam 6. did. The output of the first laser beam 6 was increased at 10 W / sec. When the output of the first laser beam 6 reached 80 W, the output was maintained for 20 seconds, and then the laser irradiation was stopped.

  Thereafter, the glass material lump 2 was cooled to obtain a flat glass material. The obtained glass material had a diameter of 4.7 mm and was confirmed to be homogeneous by observation with a stereomicroscope.

(Comparative Example 1)
Using the glass raw material lump 2 and the glass material manufacturing apparatus 1 prepared by the same method as in Example 1, the glass raw material lump 2 was heated and melted under the following conditions to produce a glass material. The specific procedure is shown below.

  First, 0.32 g of the glass raw material block 2 was placed on the molding surface 10 a of the molding member 10. Next, nitrogen gas as the gas 4 was supplied to the hole 3 from the gas supply means, and the glass raw material block 2 was suspended above the molding surface 10a. In this state, the glass material block 2 is irradiated with the first laser beam 6 through the hole 3 from the lower first laser light source 5 and the second laser beam from the upper second laser light source 7. 8 was irradiated to the glass raw material block 2. Each of the first and second laser beams 6 and 8 increases the output at 2 W / second, and when the output reaches 40 W (total 80 W), the output is maintained for 5 seconds to completely complete the glass raw material block 2. To melt. After complete melting, the output was maintained for another 30 seconds, and then laser irradiation was stopped.

  Thereafter, the glass material lump 2 was cooled to obtain a flat glass material. The obtained glass material had a diameter of 5.1 mm, and the presence of a heterogeneous phase due to the heterogeneity of the composition was confirmed by observation with a stereomicroscope.

DESCRIPTION OF SYMBOLS 1, 21, 31 ... Glass material manufacturing apparatus 2 ... Glass raw material lump 3 ... Hole 3a, 3b ... 1st, 2nd hole 4 ... Gas 5 ... 1st laser light source 6 ... 1st laser beam 7 ... 2nd Laser light source 8 ... second laser beam 10 ... molding member 10a ... molding surface 11 ... first laser beam irradiation part 12 ... second laser beam irradiation part 13 ... melting part 14 ... holding member

Claims (5)

A method for producing a glass material by cooling after heating and melting in a state where the glass raw material lump is suspended,
A step of suspending the glass raw material mass by ejecting gas from below to above;
Irradiating the glass raw material lump with a laser beam from below and above with the glass raw material lump suspended;
With
In the step of irradiating the laser beam, the glass raw material lump is heated and melted, and after the glass raw material lump is completely melted by the heating and melting into a molten glass lump, the output of the laser beam irradiated from below is A method for producing a glass material, which is adjusted to be higher than the output of a laser beam irradiated from above.   The method for producing a glass material according to claim 1, wherein a state in which an output of the laser beam irradiated from below is adjusted to be higher than an output of the laser beam irradiated from above is maintained until cooling.   The method for producing a glass material according to claim 1 or 2, wherein the output of the laser beam irradiated from above is adjusted so that an output until the glass raw material block is completely melted is equal to or higher than an output after the glass material is completely melted. . The output of the laser beam irradiated from the lower side is adjusted so that the viscosity of the molten glass lump in the irradiated portion of the laser beam irradiated from the lower side is 10 ⁻³ Pa · s or more. The manufacturing method of the glass material of any one of Claims 1.   The manufacturing method of the glass material of any one of Claims 1-4 in which the said glass raw material lump contains boric acid.

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