JP2007077004A - Heat resistant material for glass melting, glass article producing apparatus and process for producing glass article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat resistant material for glass melting by which fine oxygen-containing bubbles in molten glass which obstruct the homogeneity of the molten glass are suppressed to improve the durability of melting equipement, and to provide a glass article producing apparatus using the heat resistant material, and a process for producing the glass article realized by the glass article producing apparatus. <P>SOLUTION: The heat resistant material for glass melting is mounted on a heating production apparatus 10 for multicomponent oxide glass and comprised of a platinum-containing material F whose thickness at a surface brought into contact with molten glass is in the range of 1.1 to 50 mm. The heat resistant material for glass melting is disposed at any one selected from the group consisting of the hearth surface of tanks wherein the molten glass G flows, the side wall surface and an internal surface of tank-to-tank coupling structure in the glass article producing apparatus. In the process for producing the glass article, the glass article is produced by using the glass article producing apparatus 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a glass article, a heat-resistant material constituting the apparatus, and a method for manufacturing a glass article using the apparatus.

  Techniques for manufacturing various glass articles have evolved by overcoming many difficult challenges. For example, various glass articles represented by thin glass used for image display surfaces and thin tube glass used for liquid crystal backlights as one of the basic members that support various information devices such as flat panel displays that are undergoing remarkable development. The manufacturing technology has been further improved by tackling the problem of achieving high molding dimensional accuracy and higher homogeneity.

  Examples of hindering the homogeneity of glass articles include unmelted and crystal precipitates in molten glass, threads, strings, strikes, cords, lines, knots, and cords. , Strie, catscratch, ream, etc., but bubbles in the molten glass are also well known defects. An increase in the number of bubble defects in the molten glass is not preferable from the viewpoint of not only reducing the quality of the glass article but also reducing the production efficiency of the glass article.

From such a viewpoint, many inventions for reducing the number of bubbles in the molten glass have been made so far. Of particular interest in recent years is the problem of oxygen bubbles present in molten glass and having fine dimensions that are defects in glass articles. It pays attention to oxygen bubbles generated at the interface between the glass manufacturing apparatus containing platinum and the molten glass. As a countermeasure, Patent Document 1 describes the cause of the generation of oxygen-containing bubbles in the molten glass. From the idea that the hydrogen gas generated by the decomposition of the water that permeates the platinum that constitutes the glass melting apparatus and dissipates out of the system, oxygen remaining in the molten glass forms bubbles. It is described to reduce β-OH. Patent Document 2 also discloses an invention in which generation of bubbles can be suppressed by forming a hydrogen and oxygen impermeable film on the platinum surface. Further, Patent Document 3 proposes an invention for controlling the hydrogen partial pressure outside the melting vessel. Patent Document 4 also discloses an invention in which the generation of bubbles can be minimized within the inner container by making the melting container into a double structure.
Special table 2001-500098 gazette JP-T-2004-523449 Special table 2001-503008 gazette JP 2003-95663 A

  However, the inventions made so far are not sufficient to reduce the fine oxygen bubbles generated in the molten glass. For example, when chlorine is contained in the glass composition as a means for reducing β-OH in the glass as in Patent Document 1, chlorine may be easily generated during the reheating treatment of the glass article. In applications such as a glass substrate using a precision wiring structure such as on-glass, there is a problem that it is difficult to realize high performance due to generated chlorine. In addition, when a coating is formed on the surface of platinum as in Patent Document 2, the coating is likely to be damaged by thermal shock or mechanical impact due to glass manufacturing conditions, and even if a slight breakage occurs in the coating, There is a problem that there is a risk of causing a fatal defect. In addition, as described in Patent Document 3, adjusting the water vapor partial pressure for hydrogen partial pressure control is partial pressure control in a high-temperature environment with a temperature difference in each process, and therefore, between processes for a long time. It may be difficult to control while maintaining a balance, and it is impossible to carry out stable production for a long time. In addition, the double structure as in Patent Document 4 is adopted in the same structure for all the places where bubbles may be generated even if it is possible in a limited part of the melting apparatus. May not be possible due to structural limitations.

  In view of the above, the present inventors can suppress oxygen-containing bubbles that impede homogeneity in the molten glass, and can also improve the durability of the melting equipment. It is an object of the present invention to provide a heat-resistant material for melting, a glass article manufacturing apparatus using the heat-resistant material, and a glass article manufacturing method that can be realized by the glass article manufacturing apparatus.

  That is, the glass-melting heat-resistant material of the present invention is a glass-melting heat-resistant material made of a platinum-containing material used in a multi-component oxide glass heating production apparatus, and has a platinum-containing surface having a surface in contact with the molten glass. The thickness of the material is in the range of 1.1 mm to 50 mm.

  Here, a glass-melting heat-resistant material made of a platinum-containing material used in a multi-component oxide glass heating production apparatus, wherein the thickness of the platinum-containing material having a surface in contact with the molten glass is 1.1 mm to In the range of 50 mm, the platinum-containing material used in the heating production apparatus for bringing a glass composition that can be expressed as containing a plurality of oxide components into a molten glass state is directly in contact with the molten glass. It represents that the thickness dimension perpendicular to the surface of the platinum-containing material that forms a surface that contacts and forms an interface is 1.1 mm or more and 50 mm or less.

  Here, the platinum-containing material means a material containing platinum (Pt) as a component, that is, a metal material such as a platinum alloy or platinum, and further a ceramic material in which platinum is dispersed, and limits the platinum content. It is not a thing. However, those containing platinum as an impurity in the order of ppm do not fall under the present invention.

  The thickness of the platinum-containing material having a surface in contact with the molten glass is in the range of 1.1 mm to 50 mm because the thickness of the platinum-containing material having a surface in contact with the molten glass is less than 1.1 mm. In some cases, oxygen bubbles are easily formed, which is not preferable. Moreover, if the thickness of the platinum-containing material is less than 1.1 mm, the structural strength is also hindered, which is not preferable. From this point of view, the thickness of the platinum-containing material on the surface in contact with the molten glass is preferably thicker, more preferably 1.2 mm or more, further preferably 1.3 mm or more, more preferably 1.4 mm or more, It is more preferably 1.5 mm or more, even more preferably 1.6 mm or more, and most preferably 2.2 mm or more. On the other hand, as the thickness of the platinum-containing material having a surface in contact with the molten glass is thick, the cost required for constructing the manufacturing equipment increases. From such a viewpoint, the thickness of the platinum-containing material having a surface in contact with the molten glass is preferably as thin as possible, more preferably 40 mm or less, further preferably 30 mm or less, more preferably 20 mm or less, More preferably, it is 10 mm or less.

  The surface that is in contact with the molten glass means a portion that gets wet with the molten glass in a liquid phase, that is, a portion that directly contacts the molten glass. It does not correspond to the place of contact as referred to in the invention. Moreover, the thing which shows the property which the surface of the platinum containing material got wet when the component in a molten glass evaporates or volatilizes does not correspond to the location which contacts. That is, the surface in contact with the molten glass as referred to in the present invention is immersed in the liquid phase of the molten glass and is in contact with it to form a liquid-solid interface with the molten glass.

  And if it illustrates about the use place of the platinum containing material which contacts a molten glass directly more concretely, as a container made from a heat-resistant material which accommodates a molten glass, the inner wall surface of a crucible, a bottom face part, etc., or a tank (tank) , Melting tank (chamber), clarification tank (chamber), stirring tank (chamber), work tank (chamber), crucible, pot (pot), throat (riser), riser (feeder), forehearth ), Fore bay, drain and dog house, and their specific locations, ie, hearth (or pavement), furnace wall (or sidewall), weir (or dam wall) (Damwall)), threshold, pipe and gutt er) or the like, or a main platinum-containing material of a glass melting furnace constituting a glass article manufacturing apparatus made of a refractory metal material, or a stirrer, a twill (or a tyr) used for homogenizing molten glass Constructed from refractory metal materials such as twheel, needle, gate, damper, blender, rotor, tube, paddler, etc. and immersed in molten glass A platinum-containing material having a hollow structure, a roll, a slit, a riptile, a schema, a wetback tile, a draw bar , Spouts, cups, orifices, fusion pipes, bushings, nozzles and nozzles that are indispensable for the precision molding of molten glass, such as spouts, cups, orifices, fusion pipes, bushings and nozzles. It is a refractory material or a heat-resistant material to be configured, and corresponds to a platinum-containing material that directly contacts molten glass.

  According to the study by the present inventors, the problem concerning oxygen bubbles in molten glass has been noticed by reducing the thickness of platinum. That is, when platinum or a platinum alloy is used in a glass manufacturing apparatus, it may cause an increase in equipment costs, and sometimes a large amount of platinum is required in manufacturing a plate glass for a substrate mounted on a liquid crystal display device. Thinning of platinum equipment was carried out as a countermeasure against the surge. As a result of such measures for reducing equipment costs, a phenomenon was observed in which the bubble defects of the glass article increased significantly. As a result of investigating the platinum apparatus after the glass production apparatus was stopped, a large number of oxygen bubbles were found at or near the contact interface between the platinum apparatus and the molten glass. The inventors of the present invention have reached the present invention through repeated research focusing on this point. Therefore, among the platinum-containing materials forming an interface with the molten glass described above, the present invention is applied to the platinum-containing material used in a manufacturing apparatus required for manufacturing a plate glass for a substrate mounted on a liquid crystal display device. Particularly preferred.

  The heating and manufacturing apparatus according to the present invention may heat the glass raw material by any heat source. For example, a gas fuel such as LPG or oxygen, a solid fossil raw material in a fine powder state, or a liquefied fuel can be used. Moreover, it is also possible to electrically heat using an electrode etc., and these several methods can also be used together as needed.

  In addition to the above, the heat-resistant material for glass melting of the present invention has a thickness dimension L of a platinum-containing material having a surface in contact with the molten glass in accordance with the formula 1 when the molten glass temperature T is less than 1458.5 ° C. When the molten glass temperature T is 1458.5 ° C. or higher, the thickness dimension L is obtained by any one of the following formulas according to the formula (2).

(Equation 1)
L ≧ 1.1 (T <1458.5 ° C.)

(Equation 2)

L ≧ 0.012T-16.4 (T ≧ 1458.5 ° C.)

  The present inventors have conducted detailed research on the behavior of oxygen bubbles that become defects in molten glass from a completely different viewpoint from the inventions made so far to prevent oxygen bubbles. By specifying the molten glass temperature T required to realize the homogeneity of the molten glass by melting foreign matter contained therein, the platinum-containing material at the specified temperature T and the molten glass interface The present inventors have found a condition that can realize the thickness dimension L of the platinum-containing material that can effectively suppress foaming. And when the temperature T of the molten glass is less than 1458.5 ° C., the thickness dimension of the glass melting heat-resistant material used in the specific part as described above of the glass article manufacturing apparatus that needs to realize the specific molten glass temperature T, The desired thickness dimension L represented by Equation 1 is set, and when the temperature T of the molten glass is 1458.5 ° C. or higher, the desired thickness dimension L represented by Equation 2 is designed and configured. It was confirmed that the effect of can be realized.

  Specifically, the molten glass temperature T and the thickness dimension L of the platinum-containing material represented by Formula 1 or 2 are illustrated. If the molten glass temperature T is 1300 ° C., the thickness dimension L of the constituent member is 1 When the molten glass temperature is 1400 ° C., the thickness dimension L of the platinum-containing material is 1.6 mm, 2.2 mm, and the molten glass temperature T is 1500 ° C. When the thickness L of the contained material is 1.6 mm, 2.2 mm, 2.8 mm, and the molten glass temperature T is 1600 ° C., a configuration of 2.8 mm, 4.0 mm, etc. is preferable.

  In the formulas (1) and (2), platinum is obtained by evaluating a plate material of 100% by mass, and when the platinum content of the platinum-containing material decreases, for example, platinum and an alloy In the case of a material that has been converted to a material, it is necessary to select a material that has a foaming property at a contact interface with molten glass lower than that of platinum. In addition, sufficient examination is required for performance such as reactivity with molten glass and corrosion resistance.

  In addition to the above, the glass-melting heat-resistant material of the present invention preferably has a platinum content of at least 10% by mass because it has sufficient corrosion resistance to molten glass even at high temperatures.

  Here, the platinum content of the platinum-containing material is at least 10% by mass, as a platinum-containing material constituting a heating device having sufficient heat resistance, the platinum content in the platinum-containing material is expressed in mass percentage. This indicates that the content is 10% or more.

  The platinum-containing material may have any platinum content as long as it is 10% or more depending on the required strength and heat resistance. From the viewpoint of reducing the reactivity with, the content is preferably as high as possible. From such a viewpoint, the platinum content of the platinum-containing material is more preferably 40% or more, further preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and most preferably. Is 80% or more.

  Regarding the platinum-containing material, the contained elements other than platinum are not particularly limited as long as they can realize heat resistance over a long period of time. However, those that do not unnecessarily color the glass article as a result of elution from the surface of the platinum-containing material are preferable. For example, Ir (iridium), Os (osmium), Rh (rhodium), Zr (zirconium) , Ru (ruthenium), Pd (palladium), Si (silicon), Y (yttrium), Ce (cerium), La (lanthanum), Gd (gadolinium), Ta (tantalum), Ti (titanium), Hf (hafnium) Al (aluminum), Sc (scandium), Ca (calcium), Mg (magnesium) or Ba (barium) can be used.

  Moreover, if the platinum-containing material in addition to the above is applied to a heating manufacturing apparatus that continuously melts molten glass, the number of bubbles generated is suppressed over a long period of time. Stable quality glass articles can be mass-produced.

  Here, the platinum-containing material applied to the heating and manufacturing apparatus for continuously melting the molten glass is not a batch-type heating and manufacturing apparatus that can only produce intermittently, but uses glass melting equipment such as a tank furnace. It represents that it is what is used for the heating manufacturing apparatus of the glass melting equipment used when manufacturing a glass article continuously.

  Any glass melting equipment can be adopted as long as it is equipped with a heating device capable of heating to 700 ° C. or higher and can produce a homogeneous molten glass continuously. . And the speed | rate which produces | generates a molten glass continuously is not specifically limited.

  In addition to the above, the glass-melting heat-resistant material of the present invention inhibits homogeneity other than bubbles if the platinum-containing material is applied to a heating production apparatus having a molten glass flow part of 1 liter or more. It is preferable because it has a capacity for holding the molten glass sufficient to heat and melt the defects, striae, knots, and the like that cause the molten glass, and the molten glass can be made more homogeneous.

Here, the platinum-containing material is applied to a heating device having a molten glass retention part of 1 liter or more, and a heating production device having an appropriate heat source used for the platinum-containing material according to the present invention is a molten material. It has a substantially container-like structure capable of realizing the function of flowing glass, and the size of the internal volume of the structure part for flowing molten glass is 1 × 10 ³ cm ³ or more.

  When the molten glass flow part is more than 1 liter, the molten glass flow rate is such that the molten glass remains in the same apparatus for a sufficient time until bubbles of fine dimensions are formed in the molten glass. There is a risk that a portion having a relatively low speed is formed in a part of the flow of the molten glass fluidized portion. This means that bubbles are likely to be formed depending on the relative speed ratio between the bubble formation rate in the molten glass and the flow rate of the molten glass. In other words, if it exceeds 1 liter, it is sufficient to completely dissolve foreign matter, knots, etc. in the molten glass in the molten glass, but on the other hand, it aims to efficiently suppress the generation of bubbles in the molten glass. There are cases where it is not desirable to achieve this. Therefore, by applying the present invention to a heating and manufacturing apparatus having a structure that meets such conditions, it is preferable because the foam has a uniform quality in which the generation of foam is suppressed.

  In addition to the above, the glass-melting heat-resistant material of the present invention is such that the platinum-containing material is made of glass, ceramics, crystallized glass, concrete, mortar, and heat-resistant metal on at least a part of the back side of the surface that contacts the molten glass. If the platinum-containing material is supported by one or more materials selected from the group, the platinum-containing material is protected against various physicochemical loads applied from the outside of the platinum-containing material. This is preferable because the molten glass in a state can be continuously supported for a long time.

  Here, the platinum-containing material is one or more materials selected from the group consisting of glass, ceramics, crystallized glass, concrete, mortar, and refractory metal at least partly on the back side of the surface that contacts the molten glass. It is supported by the surface of the platinum-containing material corresponding to the opposite side of the surface that is in direct contact with the molten glass in a high temperature state, and a part of the total area is in contact with another member This means that the other member is in a supported state, and the other member is at least one material selected from the group consisting of glass, ceramics, crystallized glass, concrete, mortar, and refractory metal.

  Each member that abuts and supports does not necessarily need to be in a solid state, but needs to have a function of suppressing the deformation of the platinum-containing material over time in a high temperature state. In addition, the member that abuts and supports does not need to be a single member, and may be a combination of a plurality of members. Moreover, it is preferable that it is a material with poor reactivity in a high temperature state with a platinum containing material.

  Further, the heat-resistant material for glass melting according to the present invention suppresses the generation of appropriate oxygen-containing bubbles even when a clarifier such as arsenic (As) that absorbs oxygen by oxidation-reduction reaction is contained in the molten glass. However, it is possible to realize a particularly large effect when applied to the production of molten glass in a state where no clarifier is added or in a state where the amount of clarifier added is extremely small.

  The glass article manufacturing apparatus according to the present invention includes at least one selected from the group consisting of the above-described heat-resistant material for melting glass and the inner surface of the structure connecting the hearth surface, the side wall surface, and the tank of the heating manufacturing apparatus. It is arranged on the surface.

  Here, the heat-resistant material for glass melting described above is disposed on one or more surfaces selected from the group consisting of the furnace floor surface, the side wall surface, and the inner surface of the structure connecting the tanks of the heating production apparatus. A heating apparatus in which the molten glass flows through a heat-resistant material for glass melting having a surface in contact with the molten glass and having a thickness of the platinum-containing material containing platinum in the range of 1.1 mm to 50 mm, specifically, The bottom surface of the tank, or the side surface, and the inner surface of the connecting structure provided to move, that is, flow, the molten glass from the tank to the tank, such as a plurality of tubes and tubs between the tanks. Of these, the structure is arranged at least in any one place.

  Even if the glass article manufacturing apparatus of this invention gave the single heat-resistant material for glass melting, the thing improved the effect by using together the heat-resistant material for glass melting may be sufficient as it. Moreover, the thing at the time of use of the heat-resistant material for glass melting may be improved by using together with other means.

  Moreover, if the glass article manufacturing apparatus of this invention has the temperature of the molten glass in an apparatus in addition to the above in 700 degreeC-2200 degreeC, the foreign material other than a bubble by making the viscosity of a molten glass into a sufficiently low viscosity state, It is possible to deal with a range from a viscosity that can homogenize defects such as knots and striae to a viscosity that is suitable for glass articles by precision molding into a predetermined shape. In such a viscosity range, the generation and formation of fine-sized bubbles can be reliably suppressed in the molten glass.

  That the temperature of the molten glass in the apparatus is 700 ° C. to 2200 ° C. is specified by measuring the temperature of the molten glass with a thermocouple or an optical method. Although it is effective to lower the viscosity of the molten glass when the temperature of the molten glass exceeds 2200 ° C., there are problems such as shortening the useful life of the incidental equipment of the apparatus for heating the molten glass. Since it becomes easy to produce, it is not preferable. In addition, if the temperature of the molten glass is lower than 700 ° C., it may be difficult to form a glass article that is difficult to be formed into an appropriate shape when the molten glass is formed.

  In addition to the above, the glass article manufacturing apparatus of the present invention is arranged in a so-called downstream process in which the glass-melting heat-resistant material reaches the forming apparatus from the tank in which the equipment for performing physical stirring operation is mounted. If it becomes, it does not form oxygen-containing bubbles of fine dimensions on the apparatus wall, and it is preferable because there is less possibility that fine bubbles are mixed into the molded glass article.

  Further, the oxygen-containing bubbles having fine dimensions described above represent, for example, bubbles having a dimension in which the flying speed is smaller than 2.5 cm / hour in molten glass at 1500 ° C.

  Moreover, if the glass article manufacturing apparatus of this invention manufactures plate glass in addition to the above, since it becomes possible to further improve the quality of the high quality plate glass used for various uses, it is preferable.

  Here, to manufacture a plate glass is to form a glass sheet having various dimensions by making full use of various molding apparatuses in a homogenized state by being heated by a molten glass heating apparatus to form a molten glass. Means. As the molding apparatus, for example, various molding apparatuses such as a float molding apparatus, an overflow down draw molding apparatus, a slot down draw molding apparatus, a roll-out molding apparatus, and a lead low molding apparatus can be used.

  In addition to the above, the glass article manufacturing apparatus of the present invention is preferably an apparatus that manufactures flat glass for flat panel displays because it can be used as a flat glass capable of manufacturing flat panel displays having high image quality.

  Here, any display system may be adopted for the flat panel display. That is, for example, a liquid crystal display (LCD), a plasma display (PDP: Plasma Display Panel), an inorganic or organic EL display, a field emission display (FED: Field emission display), or a SED (Surface Conduit Emitter Display), Fluorescent display tube display (VFD: Vacuum Fluorescent Display), electroluminescent display (ELD: Elctro Luminescent Display), light emitting diode display (LED Display (Light Emitting Diode Display)), electroluminescent Mick Display (ECD: Elctro Cromic Display), an electrophoretic display (EPD: Electrophoretic Display) or may be such.

  In addition to the above, the glass article manufacturing apparatus of the present invention can be used for various sizes of liquid crystal display devices ranging from a small display device to a large display device exceeding the sixth generation, as long as it manufactures a glass plate for mounting a liquid crystal display device. It is preferable because a plate glass having high homogeneity can be manufactured.

  If it is a liquid crystal display device, the present invention can be adopted regardless of differences in liquid crystal elements, image display methods, and the like. For example, the liquid crystal can be used regardless of the type of nematic liquid crystal, smectic liquid crystal, or cholesteric liquid crystal, and the image display method can be adopted regardless of the difference in various methods such as STN and TFT. it can.

As the plate glass mounted on the liquid crystal display device, a non-alkali glass or a glass composition having a low alkali content is preferable. For example, as a glass composition, if the component is expressed in terms of mass percentage in terms of oxide, a glass composition such as SiO ₂ 40 to 85%, Al ₂ O _{3 1 to} 28%, RO 2 to 45% (RO = MgO + CaO + ZnO + SrO + BaO). Is preferred.

  In addition, it is important to note that a glass article manufacturing apparatus for manufacturing a plate glass for mounting a liquid crystal display device suppresses the generation of platinum particles in molten glass in addition to bubbles. That is, it is important to reduce the number of platinum particles in the molten glass generated by peeling, recrystallization, etc. from the platinum-containing material as much as possible, and it is more preferable to employ such an equipment configuration. For example, it is preferable that a protective material such as a ceramic having a function of covering platinum is applied to a portion where the platinum particles of the glass article manufacturing apparatus are easily generated.

  If the glass article manufacturing apparatus of the present invention is an apparatus for manufacturing a plate glass for a solid-state imaging device in addition to the above, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor: complementary metal oxide) This is preferable because it can correspond to various solid-state imaging devices having various functions such as semiconductors.

  In order to manufacture a plate glass for a solid-state imaging device, the glass article manufacturing apparatus according to the present invention, and further, trace radioactive elements such as uranium, thorium, or radium that cause generation of α-rays are ppb (parts per billion). Even if it is an order, it is preferable that it becomes a structure which is hard to elute.

  The glass article manufacturing apparatus of the present invention can be applied to various glass article manufacturing apparatuses in which arrangement of structural materials that require high-temperature heating is indispensable in addition to the above-described plate glass. For example, it is used as a melting furnace for manufacturing glass fibers, high-precision cylindrical glass tubes for light sources such as liquid crystal backlights and xenon flash lamps, lenses for optical components, etc., and it is necessary to manage the refractive index, dispersion, and transmittance. It can be employed as a glass article manufacturing apparatus for manufacturing glass articles such as various optical glasses, crystallized glass materials and the like frequently used for building materials and home appliances.

  The glass article manufacturing method of the present invention is characterized by manufacturing a glass article using the glass article manufacturing apparatus described above.

  Here, manufacturing a glass article using the glass article manufacturing apparatus described above is a platinum-containing material that is mounted on a multi-component oxide glass heating manufacturing apparatus as described above, and includes molten glass and A structure in which a heat-resistant material for glass melting in which the thickness of the platinum-containing material on the contacting surface is within a range of 1.1 mm to 50 mm connects between the hearth surface, the side wall surface, and the tank of the heating device through which the molten glass flows. It represents that a glass article is manufactured by using a glass article manufacturing apparatus disposed on one or more surfaces selected from the group consisting of inner surfaces.

  The glass article manufacturing apparatus of the present invention does not prevent other means for homogenizing molten glass, combined use with different methods or apparatuses. It is meaningful to make the present invention more preferable by appropriately combining the present invention with other methods. For example, the present invention can be used in combination with various molten glass stirring devices, molten glass decompression devices, molten glass bubbling devices, and the like.

  (1) As described above, the glass-melting heat-resistant material of the present invention is a glass-melting heat-resistant material made of a platinum-containing material used in a multi-component oxide glass heating production apparatus, and is in contact with the molten glass. Since the thickness of the platinum-containing material having a surface to be in the range of 1.1 mm to 50 mm, generation of bubbles having a high oxygen content in the glass can be suppressed.

  (2) Further, the heat-resistant material for glass melting of the present invention has a lower limit of the thickness of the platinum-containing material when the temperature T of the molten glass is less than 1458.5 ° C. Since the lower limit value of the thickness of the platinum-containing material when the glass temperature T is 1458.5 ° C. or more is set to (0.012T-16.4) mm, the thickness of the platinum-containing material However, it becomes an appropriate dimension in relation to the temperature of the molten glass.

  (3) Moreover, the heat-resistant material for glass melting of the present invention suppresses the generation of bubbles having a high oxygen content at the interface and has a high high temperature durability even when the platinum content of the platinum-containing material is at least 10% by mass. This contributes to stable production over a long period of time.

  (4) Moreover, if the heat-resistant material for glass melting of the present invention is characterized in that the platinum-containing material is applied to a heating production apparatus for continuously melting molten glass, a large amount of melting Even with an apparatus that continuously heats glass, it is possible to eliminate the generation of bubbles having a fine dimension and a high oxygen content. Therefore, by using such an apparatus, glass can be produced at a high production rate. Even when an article is produced, it is preferable because stable production can be realized.

  (5) Moreover, the heat-resistant material for glass melting of the present invention is such that the platinum-containing material is made of at least a part of the back side with respect to the surface in contact with the molten glass from glass, ceramics, crystallized glass, concrete, mortar and heat-resistant metal. If supported by a material selected from the group, the platinum-containing material is supported by an optimum material according to the temperature and atmosphere in which the platinum-containing material is used, so that high durability can be realized.

  (6) The glass article manufacturing apparatus according to the present invention includes the heat-resistant material for glass melting according to any one of the above, comprising a furnace floor surface, a side wall surface, and an inner surface of the structure connecting between the tanks in which the molten glass stays. Since it is disposed in any of the groups, it is possible to effectively prevent the formation of bubbles at a predetermined portion of the platinum-containing material in which fine bubbles having a high oxygen content are easily formed in the molten glass. .

  (7) Moreover, if the temperature of the molten glass in the apparatus is 700 ° C. to 2200 ° C., the glass article manufacturing apparatus of the present invention is applied to a temperature range in which bubbles are easily formed. The rate at which high bubbles are formed can be reduced, and a homogeneous molten glass can be easily realized.

  (8) Moreover, if the glass article manufacturing apparatus of this invention manufactures plate glass, it will be easy to manufacture the plate glass utilized for various uses in the environment where a bubble with a high oxygen content rate is hard to mix. Therefore, it is preferable.

  (9) Moreover, if the glass article manufacturing apparatus of this invention is an apparatus which manufactures the plate glass for flat panel displays, even if it is utilized in the use for which the plate glass which has various dimensions is required, plate glass A plate glass having high homogeneity can be stably produced in large quantities regardless of the dimensions.

  (10) Furthermore, if the glass article manufacturing apparatus of this invention manufactures the plate glass for liquid crystal display device mounting, the thin plate glass which has a large area which does not have a fine bubble with a high oxygen content will be continuously formed. Therefore, it is possible to manufacture a plate glass having a large area dimension required from being mounted on a large screen display in a state having a degree of homogeneity that can satisfy a customer.

  (11) Moreover, if the glass article manufacturing apparatus of this invention is an apparatus which manufactures the plate glass for solid-state image sensors, it will manufacture the plate glass which has the high homogeneity indispensable for comprising the image sensor which has a high pixel. It is something that can be done.

  (12) Since the glass article manufacturing method of the present invention uses the glass article manufacturing apparatus described above to manufacture a glass article, the number of bubbles with a high oxygen content generated in the melting step is minimized. It can be suppressed to the limit.

  Hereinafter, a glass melting heat-resistant material of the present invention, a glass article manufacturing apparatus using the heat-resistant material, and a glass article manufacturing method using the glass article manufacturing apparatus will be specifically described based on examples.

  First, the content of the test stage level evaluation conducted by the inventors in the present invention will be described below.

Glass composition beta-OH content of glass is represented by the mass percentage of alkali-free glass (as oxide of 518ppm is, _SiO 2 59 _wt%, Al _{2 O} 3 17 _wt%, B _{2 O} 3 10 wt% , MO (M = Ca, Mg, Ba, Sr, Zn) 14% by mass of glass) is preliminarily melted and homogenized, and both sides corresponding to a light-transmitting surface having a thickness of 0.7 mm are mirror glass. Molded into. Since this glass is mounted on a liquid crystal display device, it is formed as a thin plate glass. This glass is cut into rectangular thin pieces of 50 × 50 × 0.7 mm, washed with pure water, and an indirect drying furnace. The one dried at 150 ° C. for 10 hours was prepared. Then, 22 plate glass samples prepared in advance were laminated on the upper edge of a platinum crucible (bottom diameter 40 mm, upper edge diameter 55 mm, height 20 mm) having a composition of 100% by mass of platinum having a predetermined thickness. In this state, it was left in a box-type heating electric resistance furnace. The heating schedule by the heating electric resistance furnace was raised to 1200 ° C. at 10 ° C./min, then placed in another box test furnace at a predetermined test temperature and allowed to stand for 30 minutes, and then the platinum crucible was tested. The sample was taken out of the furnace and cooled to room temperature to obtain a sample for observation. Evaluation in a harsh situation can be performed by observing the molten glass that is not flowing in such a state that the molten glass is maintained for a certain period of time. Next, the presence or absence of oxygen-containing bubbles generated at the interface between the glass and platinum at the bottom of the crucible and its state were observed and investigated for this observation sample. The naked eye and a 20x stereo microscope were used for the investigation. In addition, foam with a clear size, shape, and generation site, such as residual entrainment foam during softening deformation of plate glass, could be easily excluded from investigation. The evaluation was reproducible.

  Table 1 summarizes the results of investigating the thickness and heating holding temperature of various platinum crucibles by the above procedure. In Table 1, “◯” indicates that foaming was not observed at the interface between glass and platinum, and “x” indicates that foaming was observed at the interface. However, for the nature of the test, entrained bubbles generated between the laminated glass plates are excluded from the observation target. Since the bubble size is different from the bubble size generated at the platinum interface, it can be excluded with high accuracy by observing the appearance of the bubble.

  As is clear from Table 1, when the holding temperature is 1300 ° C. and 1400 ° C., the platinum-containing thickness is 0.4 mm or more, that is, 1.1 mm, 1.6 mm, and 2.2 mm. No foaming phenomenon was observed. On the other hand, for example, it was confirmed that a large number of bubbles containing oxygen were generated at the interface portion investigated at a thickness of 0.4 mm at 1600 ° C. However, foaming did not occur at 1500 ° C. if the thickness was 1.6 mm or more, that is, 1.6 mm or 2.2 mm. In addition, platinum having a thickness of 0.4 mm used at 1300 ° C. and 1400 ° C. is fragile as a structural material.

  From the series of investigations as described above, the present inventors have confirmed that there is a relationship as shown in Equation 1 and Equation 2 regarding the platinum-containing material and the molten glass temperature. It has been found that a glass article free from oxygen bubbles can be obtained by constructing a portion requiring temperature with a structural material having a predetermined thickness.

  Next, examples of applying the platinum-containing material, which is a heat-resistant material for glass melting of the present invention, to a glass article manufacturing apparatus will be described below.

  FIG. 1 is an explanatory diagram of a glass article manufacturing apparatus to which the present invention is applied. FIG. 1A is a cross-sectional view in the longitudinal direction, and FIG. 1B is a cross-sectional view taken along the line XX in FIG. This large-sized glass melting apparatus is further connected to a forming part, and the molten glass is formed in the forming part. Here, only the main part for explaining the present invention is partially illustrated. .

  The glass article manufacturing apparatus 10 has a structure in which a glass melting tank 20 and a glass clarification tank 30 are connected via a throat 50. And the glass clarification tank 30 has a structure connected to the feeder 40. The feeder 40 has a structure in which the surface of the platinum-containing heat-resistant alloy material F having a composition of 90% platinum and 10% rhodium in mass percentage is arranged as the platinum-containing material F so as to be in direct contact with the molten glass G. The platinum-containing material F has a thickness dimension of 1.1 mm on the side wall surface and 1.3 mm on the hearth surface (see FIG. 1B). A ceramic block material R is disposed outside the platinum-containing material F made of a heat-resistant alloy containing platinum in order to realize a heat insulation function and sufficient structural strength. The platinum-containing material F is supported by the support of the ceramic block material R. Support.

Then using this glass article manufacturing apparatus 10, _SiO 2 59 _wt% as represented by mass percentage of the glass composition in terms of _oxide, Al _{2 O} 3 16 _wt%, B 2 _{O 3} 9 wt%, MO (M = Ca , Mg, Ba, Sr, Zn) A procedure for manufacturing a 16% by mass non-alkali glass article (thin plate glass used as an image display unit plate glass mounted on a liquid crystal display device or a cover glass of a solid-state imaging device) will be described. .

  A plurality of glass raw materials are weighed in advance, and glass cullet is mixed in an amount corresponding to 10% by mass, and mixed to prepare glass raw material M from a shooter 21 provided in a glass melting tank 20 with a raw material charger (screw feeder) 22. Continuously charged into the melting tank 20. The introduced glass raw material M undergoes a high temperature chemical reaction by heating using the burner 23 and the electrode 24 as a heat source in the glass melting tank 20, and enters a molten state while generating various gases such as carbon dioxide gas, oxygen gas, and water vapor. Then, the reaction further proceeds and shifts to a molten glass state. The molten glass G thus produced flows through the throat 50 and then into the glass clarification tank 30 after being homogenized by bubbling B. The molten glass G is clarified after the fine residual bubbles are clarified in the glass clarification tank 30 having an internal volume of about 30 liters, and then the homogenized molten glass G is the glass melt of the present invention. As a heat-resistant material, platinum-containing material F flows into a feeder 40 disposed on the side wall and the hearth. When the glass melt heat-resistant material of the present invention is not disposed in the feeder 40 in which the temperature of the molten glass G is 1300 ° C. to 1400 ° C., fine particles generated at the interface between the molten glass G and the platinum-containing material F Bubbles may be caused by bubbles flowing into a molding part (not shown) on the tip side of the feeder 40, but by applying the present invention, such molten glass G and platinum Generation of bubbles containing fine oxygen generated at the interface with the containing material F can be suppressed.

  The platinum-containing material F has a thickness of 1.1 mm as a lower limit when the temperature T of the molten glass is less than 1458.5 ° C. as described above. The generation suppression effect is certain. Moreover, unlike the above-mentioned case, when using the platinum containing material F in the location (for example, side wall surface part of the clarification tank 30) where the temperature T of molten glass is 1458.5 degreeC or more, the thickness of the platinum containing material F is used. Is set to (0.012T-16.4) mm or more, the above bubble generation suppression effect can be ensured.

  As described above, by using the glass article manufacturing apparatus to which the heat-resistant material for glass melting according to the present invention is used, a homogeneous glass article can be obtained without introducing oxygen-containing bubbles having a minute size which becomes a problem in the glass article. It is clear that this can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a fragmentary sectional view of the glass article manufacturing apparatus of this invention, Comprising: (A) is longitudinal direction sectional drawing, (B) is principal part sectional drawing showing the XX cross section of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Glass article manufacturing apparatus 20 Glass melting tank 21 Shooter 22 Raw material charger 23 Burner 24 Electrode 30 Glass clarification tank 40 Feeder 50 Throat B Bubbling M Glass raw material G Molten glass R Refractory F Platinum containing material

Claims (12)

A heat-resistant material for melting glass composed of a platinum-containing material used in a heating and manufacturing apparatus for multi-component oxide glass,
A heat-resistant material for glass melting, wherein the platinum-containing material having a surface in contact with the molten glass has a thickness in the range of 1.1 mm to 50 mm.   Platinum in which the lower limit of the thickness of the platinum-containing material when the temperature T of the molten glass is less than 1458.5 ° C. is 1.1 mm and the temperature T of the molten glass is 1458.5 ° C. or more 2. The heat-resistant material for glass melting according to claim 1, wherein the lower limit value of the thickness of the containing material is set to (0.012T-16.4) mm.   The heat-resistant material for glass melting according to claim 1 or 2, wherein the platinum-containing material has a platinum content of at least 10% by mass.   The heat-resistant material for glass melting according to any one of claims 1 to 3, wherein the platinum-containing material is applied to a heating production apparatus for continuously melting molten glass.   The platinum-containing material is supported at least partially on the back surface side of the surface in contact with the molten glass by one or more materials selected from the group consisting of glass, ceramics, crystallized glass, concrete, mortar, and refractory metal. The heat-resistant material for glass melting according to any one of claims 1 to 4, wherein   The heat-resistant material for glass melting according to any one of claims 1 to 5 is on one or more surfaces selected from the group consisting of a hearth surface, a side wall surface, and an inner surface of a structure connecting between tanks of a heating production apparatus. An apparatus for producing glass articles, characterized in that it is disposed.   The temperature of the molten glass in an apparatus exists in 700 to 2200 degreeC, The glass article manufacturing apparatus of Claim 6 characterized by the above-mentioned.   Plate glass is manufactured, The glass article manufacturing apparatus of Claim 6 or 7 characterized by the above-mentioned.   The glass article manufacturing apparatus according to any one of claims 6 to 8, which is an apparatus for manufacturing flat glass for flat panel displays.   The glass article manufacturing apparatus according to any one of claims 6 to 9, wherein a plate glass for mounting a liquid crystal display device is manufactured.   The glass article manufacturing apparatus according to any one of claims 6 to 8, which is an apparatus for manufacturing a plate glass for a solid-state imaging device.   A glass article manufacturing method using the glass article manufacturing apparatus according to claim 6.

Images