JP5692223B2 - Molten glass processing apparatus, manufacturing method thereof, and use thereof - Google Patents

Description

  The present invention relates to a molten glass processing apparatus, a manufacturing method thereof, and an application thereof.

  In a molten glass processing apparatus, platinum or a platinum alloy is generally used as a material of a member that contacts molten glass. The platinum alloy is an alloy containing rhodium (Rh), iridium (Ir), ruthenium (Ru), gold (Au) and the like in addition to platinum (Pt). Platinum and platinum alloys have high melting points, are not easily oxidized in the air, and have low reactivity with molten glass, and are therefore suitable as materials for members that are in contact with molten glass.

However, when platinum or a platinum alloy is used, there is a problem that bubbles are generated in the molten glass. These bubbles are caused by water dissolved in the molten glass. When water is decomposed into hydrogen and oxygen, it is believed that hydrogen permeates platinum and dissipates to the outside, and oxygen remains in the molten glass to form bubbles. Also, platinum or platinum alloy members are gradually formed by platinum reacting with oxygen in the outside air to generate platinum oxide (PtO ₂ ) gas, or platinum itself is volatilized by heat. There was also a problem of volatilization.

  Therefore, in order to solve the above problem, it has been proposed to provide a low hydrogen permeation layer on the outer surface of a platinum or platinum alloy member. Glass or ceramics is used as the material for the hydrogen low-permeability layer (for example, see Patent Document 1).

Japanese National Table 2004-523449

  However, when glass or the like is used as the material for the hydrogen low-permeability layer, the glass may thermally flow downward due to its own weight and be separated from the outer surface of the member.

  Further, when ceramic is used alone as the material for the low hydrogen permeable layer, if ceramic particles are sprayed on the outer surface of the member, cracks are likely to occur in the ceramic or platinum due to the difference in thermal expansion between the ceramic and platinum.

  Particularly in recent years, alkali-free glass has been used for flat panel displays (FPD) such as liquid crystal displays (LCD). The alkali-free glass is a glass that does not substantially contain an alkali metal, and has a melting temperature higher by 100 ° C. or more than a general soda lime glass. For this reason, the use temperature of the member is high, and the above problem is easily realized.

  In recent years, an oxygen combustion burner tends to be used as a heating source for glass raw materials in a melting tank for melting glass raw materials. Oxyfuel combustion burners have better heating efficiency than air combustion burners. However, when an oxyfuel burner is used, the water concentration in the upper space in the melting tank increases, so the water concentration dissolved in the molten glass increases. For this reason, the above problem is easily realized.

  This invention is made | formed in view of the said subject, Comprising: It aims at providing the molten glass processing apparatus which can suppress the production | generation of the bubble in molten glass more effectively.

In order to solve the above-mentioned object, the present invention provides a member made of platinum or a platinum alloy whose inner surface is in contact with molten glass, a glass layer covering at least a part of the outer surface of the member, and at least the outer side of the glass layer. A molten glass processing apparatus comprising a heat-resistant fiber body infiltrated with
The heat-resistant fiber body includes glass fiber or ceramic fiber, and is expressed by mass% based on oxide, and the SiO ₂ content is 50% or more,
The glass forming the glass layer has a viscosity of 10 ^2.5 dPa · s or more at the use temperature,
A molten glass processing apparatus is provided in which the glass layer includes voids that are not in communication with the outside air.

  ADVANTAGE OF THE INVENTION According to this invention, the molten glass processing apparatus which can suppress the production | generation of the bubble in molten glass more effectively can be provided.

It is sectional drawing of the use condition of the molten glass processing apparatus in one Embodiment of this invention. It is explanatory drawing (1) of the manufacturing method of the molten glass processing apparatus. It is explanatory drawing (2) of the manufacturing method of the molten glass processing apparatus. It is a block diagram of a glass manufacturing apparatus provided with the molten glass processing apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below, and the embodiments described below do not depart from the scope of the present invention. Various modifications and substitutions can be made.

(Molten glass processing equipment)
The molten glass processing apparatus is an apparatus for processing molten glass, for example, an apparatus for melting, clarifying, adjusting temperature, conveying, stirring and the like of molten glass. In addition, the molten glass processing apparatus of this invention is not limited to this.

  FIG. 1 is a sectional view of a molten glass processing apparatus in use according to an embodiment of the present invention. For example, as shown in FIG. 1, the molten glass processing apparatus 1 covers at least a part of a platinum or platinum alloy member 3 whose inner surface 31 is in contact with the molten glass 2 and an outer surface 32 of the member 3. A glass layer 4 and a heat-resistant fiber body 5 in which at least the outer side (the side opposite to the member 3) of the glass layer 4 penetrates are provided. The glass layer 4 covers at least a part of the outer surface 32 of the member 3, thereby suppressing hydrogen contained in the molten glass 2 from passing through the member 3 and dissipating to the outside. The heat-resistant fiber body 5 suppresses the glass layer 4 from flowing heat. Each configuration will be described below.

  The member 3 is made of platinum or a platinum alloy. The platinum alloy is an alloy containing rhodium (Rh), iridium (Ir), ruthenium (Ru), gold (Au) and the like in addition to platinum (Pt). Since platinum and platinum alloys have the characteristics that they have a high melting point, are not easily oxidized in the atmosphere, and have low reactivity with the molten glass 2, they are suitable as materials for the member 3 with which the molten glass 2 comes into contact.

  The shape of the member 3 is set according to the type and application of the molten glass processing apparatus 1. For example, the shape of the member 3 is set to a box shape or a tube shape. The molten glass 2 is in contact with the inner surface 31 of the member 3, and the glass layer 4 is in contact with the outer surface 32 of the member 3.

  The glass layer 4 covers at least part of the outer surface 32 of the member 3, thereby suppressing hydrogen contained in the molten glass 2 from passing through the member 3 and dissipating to the outside. The decomposition of dissolved water is suppressed. Therefore, it is possible to suppress the generation of bubbles due to the decomposition of moisture. Moreover, volatilization of platinum or the like can be suppressed.

Glass forming the glass layer 4 is not particularly limited, for example, represented by mass% based on _{oxide, SiO 2: 50~72%, Al} 2 O 3: 0.5~24% preferably 0.5 _{23%, B 2 O 3:} 0~12%, MgO: 0~8%, CaO: 0~14.5%, SrO: 0~24%, BaO: 0~13.5%, Na 2 O + Li 2 O + K ₂ O: 0 to 15% is contained, and MgO + CaO + SrO + BaO is 9 to 29.5%. In this case, further _ZrO 2: may contain 0 to 5%.

  When the molten glass 2 is non-alkali glass, the glass forming the glass layer 4 is preferably non-alkali glass. This is to prevent alkali metal in the glass layer 4 from being mixed into the molten glass 2 when the member 3 is damaged.

The alkali-free glass for forming the glass layer 4 is not particularly limited, but for example, expressed in terms of mass% based on oxide, SiO ₂ : 50 to 66%, Al ₂ O ₃ : 10.5 to 24%, preferably 10. _{5~22%, B 2 O 3:} 0~12%, MgO: 0~8%, CaO: 0~14.5%, SrO: 0~24%, BaO: containing 0 to 13.5%, MgO + CaO + SrO + BaO is 9-29.5%. In this case, further _ZrO 2: may contain 0 to 5%. Preferably, SiO ₂ : 58 to 66%, Al ₂ O ₃ : 15 to 22%, B ₂ O ₃ : 5 to 12%, MgO: 0 to 8%, CaO: 0 in terms of mass% based on oxide. -9%, SrO: 3 to 12.5%, BaO: 0 to 2%, and MgO + CaO + SrO + BaO is 9 to 18%.

The glass forming the glass layer 4 has a viscosity η of 10 ^2.5 dPa · s or more (preferably 10 ^2.8 dPa · s or more, more preferably 10 ^3.5 dPa · s or more) at the use temperature. . When the viscosity η is too low, the glass thermally flows downward due to its own weight, or the glass flows out through the heat resistant fiber body 5, and the glass layer 4 is separated from the member 3. On the other hand, when the viscosity η is too high, it is difficult to form the continuous glass layer 4, and it is difficult to form a void 7 (described later in detail) that does not communicate with the outside air inside the glass layer 4. Therefore, the viscosity η is preferably 10 ^4.8 dPa · s or less, more preferably 10 ^4.5 dPa · s or less, at the use temperature.

  Here, the use temperature refers to a temperature in a state where the member 3 is in contact with the molten glass 2. The operating temperatures of the molten glass 2, the member 3, and the glass layer 4 are usually substantially the same.

  At least a part of the glass forming the glass layer 4 penetrates the heat resistant fiber body 5 at the use temperature. The penetration depth D2 of the glass layer 4 into the heat resistant fiber body 5 is desirably 0.1 mm or more. Here, the penetration depth D2 means an average value. If the penetration depth D2 is too small, it is difficult to suppress the heat flow of the glass layer 4 by the heat resistant fiber body 5.

  In the present embodiment, as shown in FIG. 1, only a part of the glass forming the glass layer 4 penetrates the heat resistant fiber body 5, but as long as the glass layer 4 is in contact with the member 3. All of the glass forming the glass layer 4 may penetrate into the heat resistant fiber body 5.

  The glass forming the glass layer 4 is desirably glass having higher wettability to the member 3 than the heat-resistant fiber body 5 at the use temperature. Thereby, the adhesiveness of the glass layer 4 and the member 3 can be improved.

  The contact angle θa between the glass forming the glass layer 4 and the material constituting the member 3 (for example, platinum or platinum alloy) depends on the type of glass, but is 30 to 60 °, preferably at the operating temperature, preferably It is 45-55 degrees.

  Here, the contact angle is based on the contact angle defined in JIS R 3257-1999. In the present invention, the contact angle θa is set such that a test plate formed of a material constituting the member 3 (for example, platinum or a platinum alloy) is installed horizontally, and a glass droplet forming the glass layer 4 is left on the test plate. Measured. This contact angle can be measured by a commercially available apparatus.

  On the other hand, the contact angle θb between the glass forming the glass layer 4 and the material (for example, glass or ceramics) constituting the heat resistant fiber body 5 is, for example, 60 to 110 °, preferably 70 to 110 ° at the operating temperature. It is. When contact angle (theta) b is too small, the adhesiveness of the glass layer 4 and the member 3 will worsen. Moreover, when the contact angle θb is too large, the adhesion between the glass layer 4 and the heat-resistant fiber body 5 is deteriorated.

  In the present invention, the contact angle θb is set such that a test plate (for example, a glass plate or a ceramic plate) formed with the same composition as the material (for example, glass or ceramics) constituting the heat-resistant fiber body 5 is installed horizontally. The glass droplets forming 4 are placed on a test plate and measured.

  The thickness D1 (including the penetration depth D2) of the glass layer 4 is desirably 0.2 mm or more. Here, the thickness D1 means an average value. If the thickness D1 is too small, the effect of providing the glass layer 4 is not sufficiently exhibited. On the other hand, if the thickness D1 is excessive, the glass forming the glass layer 4 is thermally flowed downward by its own weight, and the glass layer 4 is separated from the member 3. Therefore, the thickness D1 is preferably 3 mm or less, more preferably less than 1 mm, further preferably 0.9 mm or less, and particularly preferably 0.8 mm or less.

  As shown in FIG. 1, the glass layer 4 of the present embodiment includes voids 7 and 9 that are not in communication with the outside air. The voids 7 and 9 are distributed in the glass layer 4. The gap 7 is open to the outer surface 32 of the member 3, and the gas in the gap 7 is in contact with the outer surface 32 of the member 3. The void 7 suppresses hydrogen from permeating the member 3 from the inside to the outside, and thus suppresses the generation of bubbles in the molten glass 2. Although the reason is not fully grasped, the following reasons (1) to (3) are conceivable.

  (1) Hydrogen that has permeated the member 3 from the inside to the outside is accumulated in the gas in the gap 7. Therefore, since the gas with a high hydrogen concentration is in contact with the outer surface 32 of the member 3, it is possible to prevent hydrogen from permeating the member 3 from the inside toward the outside.

  (2) Hydrogen is contained as atoms in the solid and liquid such as the member 3 and the glass layer 4, and is contained as molecules in the gas in the gap 7. Therefore, in order for hydrogen to move from the member 3 to the glass layer 4 through the gap 7, the molecules need to be decomposed into atoms after the atoms are combined into molecules. Since these bonds and decomposition require a predetermined energy, the movement of hydrogen is suppressed.

  (3) The void 7 forms a contact interface between the glass forming the glass layer 4 and the member 3, thereby expressing the surface tension of the glass with respect to the member 3, and the glass thermally flows with respect to the member 3. Is suppressed.

  The gap 9 is configured so that the gas in the gap 9 does not contact the outer surface 32 of the member 3. The gap 9 suppresses hydrogen from permeating the member 3 from the inside to the outside for the same reason as the above (2), and consequently suppresses the generation of bubbles in the molten glass 2.

  It is desirable that the gaps 7 and 9 not communicating with the outside air occupy 2 to 70% of the cross section of the glass layer 4 in total. If the proportion of the voids 7 and 9 is too low, the effects (1) to (3) described above cannot be obtained sufficiently. On the other hand, if the proportion of the gaps 7 and 9 is too high, the gaps 7 and 9 communicate with the outside air, and the mechanical strength of the glass layer 4 is lowered. A more preferred range is 5 to 65%, a further preferred range is 10 to 60%, and a particularly preferred range is 20 to 50%.

  Although the glass layer 4 of the present embodiment includes both the voids 7 and 9, the present invention is not limited to this. For example, the glass layer 4 may include only the voids 7.

  Moreover, although the space | gap 7 and 9 of this embodiment is formed in the part which is not osmose | permeating the heat resistant fiber body 5 among the glass layers 4, as shown in FIG. 1, as long as it does not communicate with external air. The heat-resistant fiber body 5 may be formed in a portion penetrating. Incidentally, in this case, the gas in the gaps 7 and 9 comes into contact with the heat resistant fiber body 5.

  The heat-resistant fiber body 5 suppresses the glass layer 4 from flowing heat. Further, the heat resistant fiber body 5 extends outward from the glass layer 4, thereby blocking the flow of outside air in contact with the glass layer 4. This is because when fresh outside air comes into contact with the glass layer 4, the hydrogen concentration and moisture concentration of the gas in the gaps 7 and 9 are lowered.

  The heat resistant fiber body 5 includes glass fiber or ceramic fiber. Here, heat resistance means that in the case of glass fiber, the glass fiber has a softening point higher than the use temperature, and in the case of ceramic fiber, it means that the ceramic fiber has a melting point higher than the use temperature. . Since these fibers are hardly thermally deformed at the use temperature, the heat flow of the glass layer 4 can be suppressed.

  The heat resistant fiber body 5 is an aggregate of these fibers. Although the form of the heat resistant fiber body 5 is not particularly limited, a plurality of fibers may be knitted in a cloth shape, or a plurality of fibers may be entangled in a lump shape. A fabric in which a plurality of fibers are knitted is excellent in flexibility and workability. The average length of the fibers is preferably 10 mm or more.

The heat-resistant fibrous body 5 is expressed by mass% based on oxide, and has a SiO ₂ content of 50% or more. When the SiO ₂ content is less than 50%, the glass that forms the glass layer 4 with respect to the heat-resistant fiber body 5 has too high wettability, so that the glass flows out through the heat-resistant fiber body 5 and the glass layer 4 Is separated from the member 3.

  The thickness D3 (including the penetration depth D2) of the heat resistant fiber body 5 is preferably 0.5 mm or more. Here, the thickness D3 means an average value. When the thickness D3 is less than 0.5 mm, the heat-resistant fiber body 5 has insufficient rigidity, and the effect of suppressing the heat flow of the glass layer 4 cannot be sufficiently obtained.

  A heat insulating member 6 may be provided outside the heat resistant fiber body 5. The heat insulating member 6 is made of a refractory or the like. The heat insulating member 6 relaxes cooling by the outside air and suppresses deformation of the member 3, the heat resistant fiber body 5, and the like due to the liquid pressure of the molten glass 2.

(Method for manufacturing molten glass processing apparatus)
Next, a method for manufacturing the molten glass processing apparatus 1 will be described.

  This manufacturing method includes a step of forming the glass layer 4 by forming a coating layer containing glass powder between the member 3 and the heat-resistant fiber body 5 and firing the coating layer.

  Specifically, first, as shown in FIG. 2, a coat layer 8 is formed by applying and drying a slurry containing glass powder on at least a part of the outer surface 32 of the member 3.

  The slurry preferably contains an inorganic binder or an organic binder. As the inorganic binder, colloidal silica or the like is used. As the organic binder, a water-soluble polymer (for example, trade name: Metrows, manufactured by Shin-Etsu Chemical Co., Ltd.) is used.

  A method of applying the slurry may be a general method, and for example, a spray coating method, a spin coating method, a screen printing method, a brush coating, or the like is used. Instead of applying the slurry, a film obtained by drying the slurry may be attached.

  The temperature for drying the applied slurry is preferably 40 to 130 ° C.

  Next, as shown in FIG. 3, the heat resistant fiber body 5 is attached to the outside of the coat layer 8. In that case, you may hold | maintain the outer side of the heat resistant fiber body 5 with the heat insulation member 6 shown in FIG.

  Finally, the assembly shown in FIG. 3 is fired. Thereby, the glass powder contained in the coat layer 8 is heat-fluidized to become the glass layer 4 shown in FIG. 1, and the gap between the glass powders becomes gaps 7 and 9 shown in FIG.

  Firing conditions are appropriately set according to the type of glass powder and the ratio of the voids 7 and 9. For example, the firing is performed in the atmosphere at substantially the same temperature as the use temperature.

  Thus, the molten glass processing apparatus 1 shown in FIG. 1 is obtained. Since this manufacturing method does not require a thermal spraying device or the like, it is possible to provide the glass layer 4 and the heat-resistant fiber body 5 on the member 3 which is an existing facility.

  In the present embodiment, the heat-resistant fibrous body 5 is attached to the outside of the coat layer 8 after the coat layer 8 is formed, but the present invention is not limited to this. For example, after applying a slurry containing glass powder to the inside of the heat resistant fiber body 5, the inside of the heat resistant fiber body 5 is attached to the outer surface 32 of the member 3 and dried to form the coat layer 8. Also good.

(Glass manufacturing equipment)
Next, the glass manufacturing apparatus provided with the said molten glass processing apparatus 1 is demonstrated.

  FIG. 4 is a block diagram of a glass manufacturing apparatus including the molten glass processing apparatus 1. As shown in FIG. 4, the glass manufacturing apparatus 10 includes a dissolution tank 11, a clarification tank 12, a stirring tank 13, and a forming apparatus 14. The dissolution tank 11, the clarification tank 12, the stirring tank 13, and the molding apparatus 14 are connected by transport pipes 15 to 17.

  The melting tank 11 melts the glass raw material to produce molten glass. The inner wall of the dissolution tank 11 is provided with a raw material inlet, a plurality of burners, and the like. Examples of the burner include an air combustion burner and an oxyfuel combustion burner. From the viewpoint of environmental protection, an oxyfuel combustion burner is preferable.

  The glass raw material introduced from the raw material introduction port is heated by the radiant heat of the flame ejected by the burner to become molten glass. The molten glass is sent to the clarification tank 12 through the transport pipe 15.

  The clarification tank 12 floats and removes bubbles contained in the molten glass. These bubbles are mainly generated when the powdery glass raw material is melted. In order to promote the rising of bubbles, for example, the upper space in the clarification tank 12 may be decompressed. The molten glass in the clarification tank 12 is sent to the stirring tank 13 through the transport pipe 16.

  The agitation tank 13 agitates and homogenizes the molten glass. As an apparatus for stirring the molten glass, for example, a rotating member such as a stirrer is used. The molten glass in the stirring tank 13 is sent to the molding apparatus 14 via the transport pipe 17.

  The forming device 14 forms molten glass into a predetermined shape. The forming device 14 may be a general device used for forming molten glass. For example, when the molten glass is formed into a strip shape, a float forming device or a fusion forming device is used as the forming device 14. Moreover, the shaping | molding apparatus 14 uses a casting molding apparatus, when shape | molding molten glass in a bottle shape. The molded molten glass is gradually cooled and then cut into predetermined dimensions as necessary to obtain a product.

  In the glass manufacturing apparatus 10, the molten glass processing apparatus 1 is used for at least some inner walls (particularly, side walls and bottom walls) of the dissolution tank 11, the clarification tank 12, the stirring tank 13, and the transfer pipes 15 to 17.

  Thus, since the glass manufacturing apparatus 10 by this embodiment is equipped with the molten glass processing apparatus 1 and the shaping | molding apparatus 14 which forms the molten glass supplied from the molten glass processing apparatus 1 in a predetermined shape, in molten glass Generation of bubbles can be suppressed. As a result, a high quality glass product can be manufactured.

(Glass manufacturing method)
Next, the glass manufacturing method using the said glass manufacturing apparatus 10 is demonstrated.

First, a plurality of types of raw materials are mixed to prepare a glass raw material. For example, SiO ₂ : 50 to 72%, Al ₂ O ₃ : 0.5 to 24%, preferably 0.5 to 23%, B ₂ O ₃ : 0 to 12%, MgO in terms of mass% based on oxide. : 0~8%, CaO: 0~14.5% , SrO: 0~24%, BaO: 0~13.5%, Na 2 O + Li 2 O + K 2 O: contains 0~15%, MgO + CaO + SrO + BaO is 9 A plurality of types of raw materials are prepared so as to be glass of ˜29.5% (in this case, ZrO ₂ may further contain 0 to 5%).

When preparing an alkali-free glass raw material, for example, SiO ₂ : 50 to 66%, Al ₂ O ₃ : 10.5 to 24%, preferably 10.5 to 22%, in terms of mass% based on oxide. ₂ O ₃ : 0-12%, MgO: 0-8%, CaO: 0-14.5%, SrO: 0-24%, BaO: 0-13.5%, MgO + CaO + SrO + BaO is 9-29. A plurality of types of raw materials are prepared so as to be alkali-free glass that is 5% (in this case, ZrO ₂ may further contain 0 to 5%). Preferably, SiO ₂ : 58 to 66%, Al ₂ O ₃ : 15 to 22%, B ₂ O ₃ : 5 to 12%, MgO: 0 to 8%, CaO: 0 in terms of mass% based on oxide. A plurality of types of raw materials are prepared so as to be non-alkali glass containing ˜9%, SrO: 3 to 12.5%, BaO: 0 to 2% and MgO + CaO + SrO + BaO being 9 to 18%.

  Subsequently, the prepared glass raw material is thrown into the melting tank 11, and a molten glass is manufactured. Subsequently, the manufactured molten glass is sent to the clarification tank 12 through the transport pipe 15, and bubbles contained therein are floated and removed. These bubbles are mainly generated when the powdery glass raw material is melted. In order to promote the rising of bubbles, for example, the upper space in the clarification tank 12 may be decompressed. Subsequently, the molten glass in the clarification tank 12 is sent to the agitation tank 13 via the transport pipe 16, and the molten glass is agitated and homogenized. Thereafter, the molten glass in the agitation tank 13 is sent to the molding device 14 via the transport pipe 17 and molded into a predetermined shape. Examples of the molding method include a float method, a fusion method, and a casting method. The molded molten glass is gradually cooled and then cut into predetermined dimensions as necessary to obtain a product.

  In this glass manufacturing method, the molten glass processing apparatus 1 is used for at least some inner walls (particularly, side walls and bottom walls) of the dissolution tank 11, the clarification tank 12, the stirring tank 13, and the transport pipes 15 to 17.

  Thus, since the glass manufacturing method by this embodiment shape | molds the molten glass supplied from the molten glass processing apparatus 1 in a predetermined shape, it can suppress the production | generation of the bubble in molten glass. As a result, a high quality glass product can be manufactured.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Examples 1 to 12]
(Molten glass processing equipment)
First, a crucible made of platinum alloy (platinum 90% by mass, rhodium 10% by mass) was prepared as a member in contact with the molten glass. This crucible conforms to JIS H 6201-1986 and has a predetermined shape (height: 27 mm, upper outer diameter: 25 mm, bottom outer diameter: 15 mm, capacity: 10 cc, mass: 8.0 g).

  The slurry was applied to the outer surface of the prepared crucible and dried in the atmosphere at 90 ° C. for 2 hours to form a coat layer. The slurry used was prepared by mixing 67 parts by mass of glass powder (particle size: # 320 under) and 33 parts by mass of an aqueous Metrose solution (concentration: 0.3% by mass). One of the glasses A to D shown in Table 1 was used as the glass powder. Glasses A to C are alkali-free glass. Table 1 shows the composition of each glass AD.

Next, the heat-resistant fiber body impregnated with the above-mentioned Metrose aqueous solution was attached to the outside of the coat layer. One of the following commercially available products was used as the heat resistant fiber body. That is, a quartz glass cloth (made by Nichias, Siltex cloth, SiO ₂ : 99% by mass or more), a ribbon-like ceramic cloth (made by Nichias, SiO ₂ : 53 mass) as a plurality of fibers knitted into a cloth shape. %, Al ₂ O ₃ : 47% by mass), alumina cloth (manufactured by Nichias, Al ₂ O ₃ : 99% by mass or more), zirconia cloth (manufactured by Zirker, ZrO ₂ : about 90% by mass, Y ₂ O ₃ : About 10% by mass) and silica alumina cloth (manufactured by Denka, SiO ₂ : 20% by mass, Al ₂ O ₃ : 80% by mass). In addition, quartz glass wool (manufactured by Tosoh Corporation, SiO ₂ : 99% by mass or more) was used as a plurality of fibers entangled in a lump.

  Next, it was dried at 110 ° C. for 2 hours in the atmosphere with the heat resistant fiber body surrounded by a heat insulating member. As the heat insulating member, a refractory having a bottomed cylindrical shape (external dimensions: 48 mm × 48 mm × 48 mm, recess depth: 26 mm, recess inner diameter: 32 mm) containing alumina and silica was used.

Finally, molten glass is put into a platinum alloy crucible, heat-treated for 1 hour at an operating temperature T in an air atmosphere having a low moisture concentration (absolute humidity: 3 g / m ³ ), and then cooled to room temperature to melt. A glass processing apparatus was manufactured. The molten glass charged into the crucible includes non-alkali glass (in terms of mass% based on oxide, SiO ₂ : 59.4%, Al ₂ O ₃ : 17.6%, B ₂ O ₃ : 7.9% MgO: 3.3%, CaO: 3.8%, SrO: 8.0%). The alkali-free glass had a β-OH value B indicating the amount of water of 0.5 mm ⁻¹ before being put into the crucible. The β-OH value B was calculated by measuring the glass thickness C and transmittance T of a glass using a Fourier transform infrared spectrophotometer (FT-IR), and substituting the measurement results into the following equation. B = (1 / C) log ₁₀ (T1 / T2) (where T1: transmittance of glass at a reference wavenumber of 4000 / cm (unit:%), T2: minimum transmittance of glass near a hydroxyl absorption wavenumber of 3570 / cm) (unit:%))

(Evaluation of molten glass processing equipment)
Next, the molten glass processing apparatus was evaluated.

  The ratio of bubbles contained in the molten glass is obtained by imaging the inside of the crucible of the molten glass processing apparatus manufactured from above with a camera, and the ratio of the area S2 of bubbles to the area S1 of the upper surface of the molten glass in the captured image (S2 / S1). × 100). The ratio of the bubbles is preferably 15% or less, more preferably 3% or less in consideration of the high-quality display quality recently required for flat panel displays for plasma displays and liquid crystal displays. More preferably, it is 1% or less.

  The thickness of the glass layer, the proportion of voids in the cross section of the glass layer, the adhesion between the glass layer and the crucible, the thickness of the heat-resistant fiber body, the penetration depth of the glass layer into the heat-resistant fiber body is the melt produced The glass processing apparatus was halved vertically, and the cut surface was examined by observation with a microscope. Here, the thickness of the glass layer, the thickness of the heat-resistant fiber body, and the penetration depth of the glass layer into the heat-resistant fiber body are average values measured at 15 points on the cut surface.

  Viscosity η (unit: dPa · s) at the use temperature T of the glass forming the glass layer is obtained by putting a glass having the same composition as the glass into a platinum crucible and melting it, and rotating a viscometer (manufactured by Motoyama). And measured.

  The contact angle θa at the operating temperature T between the glass forming the glass layer and the material (platinum alloy) constituting the member, the glass forming the glass layer, and the material constituting the heat resistant fiber body (quartz glass or ceramics) The contact angle θb at the use temperature T was measured using a high-temperature contact angle meter (manufactured by Cruz).

(Evaluation results)
The evaluation results of the molten glass processing apparatus are shown in Tables 2 to 3. Here, Examples 1 to 5 are Examples, and Examples 6 to 12 are Comparative Examples. In Examples 7 and 9 to 12, in which the glass layer was thermally fluidized and a part of the glass layer was peeled off from the crucible, the characteristics of the glass layer (excluding viscosity η) could not be measured.

  In Examples 1 to 5, a glass layer was formed on the outer surface of the platinum alloy crucible, and the heat flow of the glass layer was suppressed by the heat resistant fiber body. Further, the glass layer contained voids that were not in communication with the outside air and were open to the member. Therefore, in Examples 1-5, it turns out that the ratio of the bubble contained in a molten glass is small compared with Examples 6-12.

  In Example 7, since the heat-resistant fiber body was not used, the glass layer thermally flowed downward due to its own weight, and a part of the glass layer was separated from the crucible.

In Example 9, since the viscosity η at the use temperature T of the glass forming the glass layer was less than 10 ^2.5 dPa · s, the glass layer thermally flowed downward due to its own weight, and a part thereof was separated from the crucible. .

In Examples 10 to 12, since the SiO ₂ content of the heat insulating fiber body is less than 50% by mass, the wettability of the glass layer with respect to the heat insulating fiber body is too high, and a part of the glass layer is made of the heat insulating fiber body. It passed and leaked outside. Moreover, the space | gap contained in the remainder of a glass layer was connected with external air.

Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application 2010-104350 filed on April 28, 2010, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Molten glass processing apparatus 2 Molten glass 3 Member 31 Inner surface 32 Outer surface 4 Glass layer 5 Heat resistant fiber body 6 Heat insulation member 7 Cavity 8 Coat layer 9 Cavity 10 Glass manufacturing apparatus 11 Dissolution tank 12 Clarification tank 13 Stirrer tank 14 Molding apparatus 15-17 Conveying pipe

Claims (14)

A member made of platinum or platinum alloy whose inner surface is in contact with molten glass, a glass layer covering at least a part of the outer surface of the member, and a heat-resistant fiber body in which at least the outer side of the glass layer penetrates A molten glass processing apparatus comprising:
The heat-resistant fiber body includes glass fiber or ceramic fiber, and is expressed by mass% based on oxide, and the SiO ₂ content is 50% or more,
The glass forming the glass layer has a viscosity of 10 ^2.5 dPa · s or more at the use temperature,
The molten glass processing apparatus in which the said glass layer contains the space | gap which is not connected with external air.   The molten glass processing apparatus according to claim 1, wherein the glass layer has a thickness of less than 1 mm.   The molten glass processing apparatus according to claim 1, wherein the gap is open to the member, and a gas in the gap is in contact with the member.   The molten glass processing apparatus according to claim 1, wherein the gap occupies 2 to 70% of a cross section of the glass layer.   The molten glass processing apparatus according to any one of claims 1 to 4, wherein the glass forming the glass layer is glass having higher wettability to the member than the heat-resistant fiber body at a use temperature.   The glass which forms the said glass layer is an alkali free glass, The molten glass processing apparatus as described in any one of Claims 1-5.   The thickness of the said glass layer is 0.2 mm or more, The molten glass processing apparatus as described in any one of Claims 1-6.   The molten glass processing apparatus according to claim 1, wherein a penetration depth of the glass layer into the heat-resistant fiber body is 0.1 mm or more.   The molten glass processing apparatus according to claim 1, wherein the heat-resistant fiber body has a thickness of 0.5 mm or more. A method for producing the molten glass processing apparatus according to claim 1,
The manufacturing method of the molten glass processing apparatus including the process of forming the said glass layer by forming the coating layer containing glass powder between the said member and the said heat resistant fiber body, and baking.   A glass manufacturing apparatus provided with the molten glass processing apparatus as described in any one of Claims 1-9, and the shaping | molding apparatus which shape | molds the molten glass supplied from the said molten glass processing apparatus in a defined shape.   The glass manufacturing method which shape | molds the molten glass supplied from the molten glass processing apparatus as described in any one of Claims 1-9 in a predetermined shape.   The glass manufacturing method according to claim 12, wherein the molten glass is alkali-free glass. The molten glass is represented by mass% based on _{oxide, SiO 2: 58~66%, Al} 2 O 3: 15~22%, B 2 O 3: 5~12%, MgO: 0~8%, CaO The glass manufacturing method according to claim 12, wherein the glass is non-alkali glass containing 0 to 9%, SrO: 3 to 12.5%, BaO: 0 to 2%, and MgO + CaO + SrO + BaO being 9 to 18%.

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