JP2019206457A - Method for manufacturing glass article - Google Patents

Abstract

To provide a method for manufacturing a glass article, capable of excellently defoaming a molten glass and preventing volatilized platinum or platinum alloy from being coagulated and mixed into the molten glass.SOLUTION: A clarification vessel 12 comprises a tubular part 21 transferring a molten glass from the upstream to the downstream, a vent part 22 provided in an upper portion of the tubular part 21 and discharging gas generated in the molten glass and a reinforcing member 23 arranged on the inner surface of the tubular part 21. The reinforcing member 23 includes a body part 23a extended in the circumferential direction of the tubular part 21 and a missing part 23b positioned at an upper portion of the tubular part 21; and in the clarification step, the molten glass is filled in the tubular part 21 and gas reaching the upper portion of the tubular part 21 in the gas passes through the missing part 23b and is discharged from the vent part 22.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing a glass article using a clarification container composed of platinum or a platinum alloy.

  As is well known, plate glass is used as a substrate in flat panel displays such as liquid crystal displays and organic EL displays. As the material of the plate glass for the substrate, alkali-free glass that does not impair the thin film characteristics such as amorphous silicon and polycrystalline silicon is preferably used.

  Glass articles such as plate glass are manufactured through each process such as a melting process, a clarification process, a homogenization process, and a molding process. For example, in the clarification process disclosed in Patent Document 1, molten glass is passed while being heated in a state in which a gas phase space is formed in a tubular clarification container composed of platinum or a platinum alloy. Thereby, the defoaming process which discharge | releases foam from a molten glass to gaseous-phase space is performed. In the upper part of the clarification container, a vent part (vent pipe) is provided for communicating with the gas phase space in the clarification container and for discharging the gas in the gas phase space to the outside.

  As the hot molten glass passes, the fining vessel also becomes hot. At that time, in order to prevent the strength of the clarification container from decreasing, an annular reinforcing member may be disposed on the inner surface of the clarification container along the circumferential direction.

JP 2014-028734 A

  In the conventional clarification process, there is a problem that the vapor phase space in the clarification container becomes high temperature and volatilization wear on the inner surface of the clarification container tends to occur. In addition, when the gas in the clarification container is discharged from the vent, the volatile component of platinum or platinum alloy contained in the gas is cooled, solidified, and mixed into the molten glass, which may deteriorate the quality of the glass article. was there.

  The present invention has been made in view of the above circumstances, and can perform a defoaming treatment of molten glass, and can prevent the volatilized platinum or platinum alloy from solidifying and mixing into the molten glass. It is a technical problem to provide a manufacturing method.

  The present invention is for solving the above-mentioned problems, and a melting step of melting a glass raw material in a melting tank to produce a molten glass, and passing the molten glass through a clarification container composed of platinum or a platinum alloy. And a forming step of forming the molten glass that has undergone the refining step as a glass article with a forming device, wherein the refining container is a method for producing the molten glass. A tubular portion that is transported from upstream to downstream; a vent portion that is provided at an upper portion of the tubular portion and that discharges gas generated in the molten glass; and a reinforcing member that is disposed on an inner surface of the tubular portion, The reinforcing member includes a main body portion extending along a circumferential direction of the tubular portion and a missing portion located at an upper portion of the tubular portion. In the refining step, the tubular portion is filled with the molten glass. Together it is, gas which has reached the upper part of the tubular portion among the gas, characterized in that it is discharged from the vent through the missing section.

  According to such a method, since the molten glass is filled in the entire internal space of the tubular portion in the clarification container, no gas phase space is formed between the inner surface of the tubular portion and the molten glass. In this case, when a conventional annular reinforcing member is used, the gas generated in the molten glass is blocked by the reinforcing member, and the gas stagnates at the upper portion of the tubular portion (see reference A in FIG. 8 described later). In the method described above, the reinforcing member includes the missing portion positioned at the upper portion of the tubular portion, so that the gas that has reached the upper portion of the tubular portion passes through the missing portion and is discharged from the vent portion. As a result, it is possible to prevent platinum from volatilizing from the inner surface of the tubular portion in a high-temperature gas phase space as in the prior art. Therefore, it is possible to prevent the mixing of platinum into the molten glass and to perform the defoaming treatment of the molten glass satisfactorily and to manufacture a high-quality glass article.

  In the above case, it is preferable that the main body portion is disposed except for an upper portion of the tubular portion, and the missing portion is constituted by a portion where the main body portion is not disposed. Thereby, since the stagnation of the gas in the upper part of the tubular part can be further suppressed, it becomes possible to manufacture a higher quality glass article.

  In the above case, the clarification container further includes a partition plate disposed on an inner surface of the tubular portion for stirring the molten glass, and the partition plate is located at an upper portion of the tubular portion and the tubular portion. It is preferable to provide the 1st opening part which lets the gas which reached | attained the upper part pass, and the 2nd opening part which lets the said molten glass pass through while being provided under the said 1st opening part. Thereby, even when it is a case where the molten glass in a clarification container is stirred with a partition plate, the gas which reached | attained the upper part of a tubular part can be passed through a 1st opening part, and can be discharged | emitted from a vent part. Therefore, the defoaming treatment of the molten glass can be performed satisfactorily, and the high-quality glass article can be manufactured by preventing the platinum from being mixed into the molten glass.

  In said case, it is preferable that said 1st opening part contacts the inner surface of the said tubular part. Thereby, since the stagnation of the gas in the upper part of the tubular part can be further suppressed, it becomes possible to manufacture a higher quality glass article.

  In the above case, the molten glass is preferably filled with the molten glass by positioning the liquid surface of the molten glass in the melting tank above the top of the inner surface of the tubular portion. Thereby, a clarification process can be performed, without forming a gaseous-phase space between the inner surface of a tubular part and molten glass reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the defoaming process of molten glass can be performed favorably and it can prevent that the volatilized platinum or platinum alloy solidifies and mixes in molten glass.

It is a side view which shows the whole structure of the manufacturing apparatus of a glass article. It is a side view of the clarification container of 1st embodiment. It is a cross-sectional view of the clarification container of 1st embodiment. It is a longitudinal cross-sectional view which shows the principal part of the clarification container of 1st embodiment. It is a cross-sectional view of the clarification container of 2nd embodiment. It is a cross-sectional view which shows the partition plate with which the clarification container of 3rd embodiment is provided. It is a cross-sectional view which shows another partition plate with which the clarification container of 3rd embodiment is provided. It is a longitudinal cross-sectional view which shows the principal part of the conventional clarification container.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment of a method for producing a glass article of the present invention.

  As shown in FIG. 1, the manufacturing apparatus 10 of the glass article which concerns on this embodiment is the dissolution tank 11, the clarification container 12, the homogenization tank (stirring tank) 13, and the state adjustment tank 14 in an order from the upstream. The forming apparatus 15 and glass supply paths 16a to 16d connecting them are provided.

  The melting tank 11 is a container for performing a melting step of obtaining molten glass Gm by melting the charged glass raw material. The dissolution tank 11 is connected to the clarification container 12 by a glass supply path 16a.

  The clarification container 12 is a container for performing a clarification process in which the molten glass Gm supplied from the dissolution tank 11 is defoamed by the action of a clarifier or the like. The clarification container 12 is connected to the homogenization tank 13 by a glass supply path 16b.

  The homogenization tank 13 is a container for performing a homogenization process in which the clarified molten glass Gm is stirred with a stirring blade or the like to make it uniform. The homogenization tank 13 is connected to the state adjustment tank 14 by a glass supply path 16c.

  The state adjustment tank 14 is a container for performing a state adjustment step of adjusting the molten glass Gm to a state suitable for molding. The state adjustment tank 14 is connected to the molding apparatus 15 by a glass supply path 16d.

  The forming device 15 forms the molten glass Gm into a desired shape. The molding apparatus 15 of this embodiment includes a molded body 15a that molds the molten glass Gm into a plate shape by an overflow downdraw method. Specifically, the molded body 15a has a substantially wedge shape in cross-sectional shape (cross-sectional shape orthogonal to the paper surface of FIG. 1), and an overflow groove (not shown) is formed in the upper part of the molded body 15a. Has been.

  The molten glass Gm supplied to the overflow groove of the molded body 15a by the glass supply path 16d overflows from the overflow groove and flows down along the side wall surfaces (side surfaces located on the front and back sides of the paper surface) of the molded body 15a. To do. The molten glass Gm flowing down fuses at the lower top of the side wall surface, whereby the glass ribbon Gr is formed. The formed glass ribbon Gr is gradually cooled by a slow cooling furnace (not shown). After the plate glass is cut out from the slowly cooled glass ribbon Gr by a first cutting device (not shown), both ends in the width direction of the plate glass are removed by a second cutting device (not shown). Thus, plate glass is manufactured as a glass article. In addition, you may manufacture a glass roll as a glass article by winding the glass ribbon Gr annealed slowly in the shape of a roll after cut | disconnecting and removing the both ends of the width direction.

  The manufactured plate glass has a thickness of 0.01 to 10 mm, for example, and is used for a flat panel display such as a liquid crystal display or an organic EL display, an organic EL illumination, a substrate such as a solar cell, or a protective cover. Note that the molding apparatus may execute another downdraw method such as a slot downdraw method.

  Hereinafter, a specific configuration of the clarification container 12 will be described with reference to FIGS. 2 and 3. The clarification container 12 includes a tubular portion 21 that transfers the molten glass Gm from upstream to downstream, a vent portion 22 that is provided at an upper portion of the tubular portion 21 and discharges gas generated in the molten glass Gm, and the tubular portion 21. A reinforcing member 23 disposed on the inner surface, a flange portion 24, and an electrode portion 25 for energizing and heating the tubular portion 21 are provided.

  Although the tubular part 21 of this embodiment is cylindrical shape, it is not limited to this shape, What is necessary is just to be provided with the space which flows the molten glass Gm inside by being tubular. A glass supply path 16 a that connects the melting tank 11 and the tubular portion 21 is connected to one end portion (upstream end portion) in the longitudinal direction of the tubular portion 21. A glass supply path 16 b that connects the homogenization tank 13 and the tubular portion 21 is connected to the other end portion (downstream end portion) in the longitudinal direction of the tubular portion 21. The tubular portion 21 is made of platinum or a platinum alloy.

  The vent portion 22 is provided so as to protrude upward from the upper portion of the tubular portion 21. The vent portion 22 is configured in a cylindrical shape (for example, a cylindrical shape), is fixed to the upper outer surface of the tubular portion 21, and communicates with the inside of the tubular portion 21. The vent portion 22 is made of platinum or a platinum alloy like the tubular portion 21.

  A plurality of reinforcing members 23 are arranged at intervals along the longitudinal direction of the tubular portion 21. Each reinforcing member 23 includes a main body portion 23 a extending along the circumferential direction of the tubular portion 21, and the main body portion 23 a is fixed (for example, welded) to the inner surface of the tubular portion 21. Further, an opening is formed inside the reinforcing member 23 so as to allow the molten glass Gm to pass therethrough. Such a reinforcing member 23 can prevent the cross-sectional shape of the tubular portion 21 from being deformed while allowing the high-temperature molten glass Gm to pass through the tubular portion 21. The reinforcing member 23 is made of platinum or a platinum alloy.

  The reinforcing member 23 includes a missing part 23 b located at the upper part of the tubular part 21. In order to reinforce the fining container 12, the reinforcing member 23 is preferably disposed over the entire circumference of the tubular portion 21. However, in the reinforcing member 23 of the present embodiment, the main body portion 23 a is located above the tubular portion 21 (circumferential direction). The part where the main body part 23a is not arranged becomes a missing part 23b. The missing portion 23 b is connected to an opening formed inside the reinforcing member 23.

  The flange part 24 is arrange | positioned at the both ends of the longitudinal direction of the tubular part 21, and is comprised with platinum or a platinum alloy. The electrode part 25 is arrange | positioned on the outer side (upper side in this embodiment) of the flange part 24, and is connected with a power supply. By applying a predetermined voltage to the electrode part 25, a current flows through the tubular part 21 via the flange part 24 and the tubular part 21 is heated. Along with this, the molten glass Gm inside the tubular portion 21 is heated.

  In the clarification process of the present embodiment, the tubular portion 21 of the clarification container 12 is filled with molten glass Gm. That is, a gas phase space is not formed in the tubular portion 21. By positioning the liquid level Gma of the molten glass Gm in the melting tank 11 above the top 21a of the inner surface of the tubular part 21, the tubular part 21 can be filled with the molten glass Gm (see FIG. 1). If the molten glass Gm is filled in the tubular portion 21 in this way, platinum will not volatilize on the inner surface of the tubular portion 21 due to a high-temperature gas phase space as in the prior art. Thereby, the situation which platinum volatilized like the past can mix in molten glass Gm can be prevented.

  In this way, when the tubular portion 21 is filled with the molten glass Gm, the gas reservoir A is formed by using a conventional annular reinforcing member L (a reinforcing member having no missing portion) as shown in FIG. This is because when the gas generated in the molten glass rises and reaches the upper part of the tubular portion 21, it is dammed by the reinforcing member L. On the other hand, in the manufacturing method according to the present embodiment, the reinforcing member 23 includes the missing portion 23 b positioned at the upper portion of the tubular portion 21. Thereby, the gas that has reached the upper portion of the tubular portion 21 passes through the missing portion 23 b and is discharged from the vent portion 22. Therefore, it is possible to suppress the gas from stagnating in the upper portion of the tubular portion 21 and forming a gas reservoir. This also prevents the volatilized platinum from being mixed into the molten glass Gm.

  The height h (mm) of the reinforcing member 23 (main body portion 23a) is a ratio (h / d) to the inner diameter d (mm) of the tubular portion 21, and can be set to 2 to 40%, for example.

  The width w (mm) of the missing portion 23b is a ratio (w / d) to the inner diameter d (mm) of the tubular portion 21 and can be set to 4 to 40%, for example.

  In addition, this invention is not limited to the structure of said 1st embodiment, It is not limited to an above-described effect. The present invention can be variously modified without departing from the gist thereof.

  In 1st embodiment, although the example which forms the missing part 23b by arrange | positioning the main-body part 23a except the upper part (part of the circumferential direction) of the tubular part 21 was shown, it is not limited to this. As in the second embodiment shown in FIG. 5, the missing portion 23b may be formed by providing a notch inside the upper portion of the annular main body portion 23a. From the viewpoint of further suppressing gas stagnation at the upper part of the tubular part 21, it is preferable to form the missing part 23b by arranging the main body part 23a except for the upper part of the tubular part 21 as in the first embodiment.

  In 1st embodiment, although the example which arrange | positions only the reinforcement member 23 on the inner surface of the tubular part 21 was shown, it is not limited to this. A partition plate 26 for stirring the molten glass may be further arranged on the inner surface of the tubular portion 21 as in the third embodiment shown in FIGS. 6 and 7.

  Each of the partition plates 26 shown in FIGS. 6 and 7 is located at the upper part of the tubular part 21 and allows the gas that has reached the upper part of the tubular part 21 to pass therethrough, and below the first opening part 26a. And a second opening 26b through which the molten glass Gm passes. The first opening 26a and the second opening 26b are closed without being connected. The area of the second opening 26b is set larger than the area of the first opening 26a.

  In the partition plate 26 shown in FIG. 6 and the partition plate 26 shown in FIG. 7, the positions of the first opening 26 a and the second opening 26 b in the cross section of the tubular portion 21 are different. Specifically, in the partition plate 26 shown in FIG. 6, the first opening portion 26a is located on the right side, whereas in the partition plate 26 shown in FIG. 7, the first opening portion 26a is located on the left side. Further, in the partition plate 26 shown in FIG. 6, the second opening 26b is located at the center, whereas in the partition plate 26 shown in FIG. 7, the first opening 26a is located on the lower side.

  In this way, the partition plates 26 having different positions of the first opening 26 a and the second opening 26 b are alternately arranged along the longitudinal direction of the tubular portion 21. Thereby, the flow of the molten glass Gm is meandering between the partition plates 26 instead of a straight line along the longitudinal direction of the tubular portion 21. For this reason, it becomes possible to perform a favorable defoaming process and homogenization of glass.

  In addition, since the first opening 26 a is provided at the upper part of the partition plate 26, the gas that has reached the upper part of the tubular part 21 can be passed therethrough. For this reason, since it can suppress that gas stagnates and the gas pool is formed in the upper part of the tubular part 21, the situation where the volatilized platinum mixes in the molten glass Gm can be prevented.

  As long as the first opening 26a is located at the upper part of the partition plate 26, the first opening 26a may have a distance from the inner surface of the tubular part 21 without contacting the inner surface of the tubular part 21, but the first opening 26a shown in FIGS. It is preferable to contact the inner surface of the tubular portion 21 as in the third embodiment. Since the first opening 26a is in contact with the inner surface of the tubular portion 21, the gas that has reached the upper portion of the tubular portion 21 passes more smoothly through the first opening 26a, so that a higher-quality glass article can be manufactured. It becomes possible.

DESCRIPTION OF SYMBOLS 10 Glass article manufacturing apparatus 11 Dissolution tank 12 Clarification container 13 Homogenization tank 14 Condition adjustment tank 15 Molding apparatus 15a Molded body 16a-16d Glass supply path 21 Tubular part 21a Top part 22 of inner surface of tubular part Vent part 23 Reinforcement member 23a Main body Part 23b missing part 24 flange part 25 electrode part 26 partition plate 26a first opening part 26b second opening part Gm molten glass Gr glass ribbon

Claims (5)

The melting step of melting a glass raw material in a melting tank to produce a molten glass, the clarification step of defoaming the molten glass by passing it through a clarification container composed of platinum or a platinum alloy, and the clarification step A glass article manufacturing method comprising a molding step of molding the molten glass as a glass article with a molding apparatus,
The clarification container includes a tubular part for transferring the molten glass from upstream to downstream, a vent part provided at an upper part of the tubular part, for discharging a gas generated in the molten glass, and an inner surface of the tubular part. A reinforcing member to be disposed;
The reinforcing member includes a main body portion extending along a circumferential direction of the tubular portion, and a missing portion located at an upper portion of the tubular portion,
In the clarification step, the tubular portion is filled with the molten glass, and the gas that has reached the upper portion of the tubular portion out of the gas passes through the missing portion and is discharged from the vent portion. A method for manufacturing a glass article. The main body portion is arranged except for an upper portion of the tubular portion,
The method for manufacturing a glass article according to claim 1, wherein the missing portion is configured by a portion where the main body portion is not disposed. The clarification container further comprises a partition plate disposed on the inner surface of the tubular portion for stirring the molten glass,
The partition plate is located above the tubular part and allows a gas that has reached the upper part of the tubular part to pass therethrough, and is provided below the first opening part and allows the molten glass to pass therethrough. The method for producing a glass article according to claim 1, further comprising two openings.   The method for manufacturing a glass article according to claim 3, wherein the first opening is in contact with an inner surface of the tubular portion.   The liquid glass of the molten glass in the melting tank is positioned above the top of the inner surface of the tubular portion, thereby filling the tubular glass with the molten glass. A method for producing a glass article according to claim 1.