WO2006030738A1

WO2006030738A1 - Coating material for platinum material, platinum material coated with such coating material, and glass manufacturing apparatus

Info

Publication number: WO2006030738A1
Application number: PCT/JP2005/016757
Authority: WO
Inventors: Toru Shoji; Mitsuo Kato; Mikio Hiyama; Tatsuya Takaya; Takashi Aitoku
Original assignee: Tanaka Kikinzoku Kogyo K.K.; Nippon Electric Glass Co., Ltd.
Priority date: 2004-09-13
Filing date: 2005-09-12
Publication date: 2006-03-23
Also published as: CN101044265A; JP2009084697A; TW200615399A; US20080090087A1; CN101044265B; TWI428473B; KR101314889B1; KR20070053749A; JP4316615B2; JPWO2006030738A1; JP4769854B2

Abstract

Disclosed is a material for coating the surface of a platinum material made of platinum or an platinum alloy. Specifically disclosed is a coating material for platinum materials which contains a fire-resistant material component including alumina and silica, and a glass component.

Description

Coating material for platinum material, platinum material coated with the coating material, and glass manufacturing apparatus

Technical field

[0001] The present invention relates to a coating material for coating a platinum material used in a high temperature environment such as a glass manufacturing apparatus. Background art

[0002] Platinum materials are generally used as constituent materials for apparatuses (such as a stirring tank, a dissolution tank, and a clarification tank) for producing high-quality glass such as optical glass and display glass. Platinum is used as a constituent material for these tower tanks because platinum does not deteriorate because it does not form an oxide layer in the atmosphere with a high melting point, and it is less likely to be deformed or damaged during operation. In addition, it has excellent chemical stability and is less likely to contaminate molten glass. As this platinum material, platinum alloys such as platinum rhodium alloy are widely used in addition to platinum (as for the platinum material applicable to the glass industry, details are given in the conventional technology column of Patent Document 1. ) O

[0003] The apparatus temperature in the glass manufacturing process is in a high temperature environment of 1200 to 1600 ° C. and 1000 ° C. or higher depending on the processing contents. The platinum material can maintain sufficient durability for a long period of time without contaminating the molten glass inside the apparatus even under the above-mentioned characteristic force and in such a high temperature environment.

[0004] However, there is a problem regarding the behavior of the outer surface of the device under the high temperature environment. This problem is the platinum oxide (PtO) in which platinum in the platinum material is a gaseous oxide.

2

) To produce a volatile loss. The volatilization loss of platinum is a factor that directly impairs the strength and stability of the platinum material at a site where the volatilization amount of the platinum apparatus is several percent of the weight of the platinum apparatus in a normal use and the volatilization amount is locally large. In addition, since the volatilized platinum adheres to the refractory material and heat insulating material installed around the glass manufacturing apparatus, a large number of members become targets for platinum recovery and purification. Furthermore, the loss due to the volatilization of expensive platinum materials in difficult-to-recover spaces is also significant. [0005] Further, in a glass manufacturing apparatus using a platinum member, there is a problem that bubbles due to moisture in the glass are generated at the interface of the platinum member during glass manufacturing (eg, Patent Document 2). This is because water in the glass decomposes, and hydrogen generated by the decomposition permeates the platinum member and is released to the outside. As a result, there is glass having a high oxygen concentration near the interface of the platinum member. This is considered to be due to the generation of oxygen bubbles.

[0006] In Patent Document 3, it is proposed to provide a hydrogen-impermeable glass-based coating on the outer surface of the platinum member in order to solve the above-mentioned problem of bubble generation during glass production.

However, as a result of studying the glass-based coating disclosed in Patent Document 3, the present inventors have not been able to sufficiently reduce the generation of bubbles during glass production. No. 10-280070

Patent Document 2: JP 2001-503008

Patent Document 3: Japanese Translation of Special Publication 2004-523449

Disclosure of the invention

[0007] A first object of the present invention is to provide a material suitable for coating a platinum material used in a high temperature environment.

A second object of the present invention is to provide a coating material for platinum material that can reduce the generation of bubbles due to moisture in the glass during glass production.

[0008] The characteristics required for a coating material of platinum material used at high temperatures are summarized as follows. First, in addition to being not melted or deformed in a high temperature environment, it has a certain degree of flexibility. It is necessary to be able to follow the deformation of the platinum material. When the equipment is started and stopped, the thermal expansion and contraction of the constituent materials occur. Therefore, a hard coating material with high strength simply fails to follow the dimensional change and causes cracking and deformation, losing its function. It is this power. Second, it must have a dense film quality and be a component that does not easily cause defects such as pinholes. The presence of defects not only leads to damage to the coating material in the process of use, but also causes contact between the substrate and the outside air, and the volatilization loss of platinum from the substrate is not sufficiently suppressed! [0009] Accordingly, metal oxides known as general refractory materials can be used in terms of strength and stability under high-temperature environments, but they are poor in flexibility and have a high melting point. For this reason, it is difficult to form a dense film by firing, and the target characteristics of the present invention are not provided.

Based on the above preconditions, the present inventors have studied the composition of a suitable coating material, and as a result, have added a glass component to a material that is a crystalline metal oxide of alumina or silica. The present invention has been conceived as being able to satisfy the above-mentioned conditions.

[0010] Further, it has been found that the generation of bubbles due to moisture in the glass can be effectively reduced during the production of a coating material that contains alumina and silica as essential components of a refractory material and contains a glass component in the glass. The present invention has been reached.

That is, the present invention is a material for coating the surface of platinum material that also has platinum or platinum alloy power, and is a coating material for a white metal material containing a refractory material component containing alumina and silica, and a glass component. It is.

[0011] The coating material in the present invention contains alumina particles, a glass component, silica particles, and Z or colloidal silica. Hereinafter, technical matters common to the first to fourth embodiments according to the present invention may be described as “the present invention”.

In the first preferred embodiment according to the present invention, colloidal silica is used as at least part of the silica. Therefore, the coating material includes alumina particles, a glass component, colloidal silica, and, if necessary, silica particles.

[0012] In the first embodiment according to the present invention, alumina particles and glass components, or further silica particles may be mixed in advance. That is, it is good also as a coating material using the pulverized material which mixed the alumina particle | grain and the glass component, or also the silica particle, and grind | pulverized the sintered compact, and colloidal silica.

In the first embodiment according to the present invention, the coating material is preferably in the form of a slurry. That is, it is preferable to use a slurry containing alumina particles, a glass component, colloidal silica, or silica particles as the coating material. As described above, powder obtained by pulverizing a sintered body of a mixture of alumina particles and glass components, or further silica particles When a crushed material is used, a slurry containing the pulverized material and colloidal silica is used as a coating material.

[0013] The slurry preferably contains a water-soluble polymer such as methylcellulose as an organic binder. The content of the organic binder is preferably in the range of 0.5 to: LO parts by weight, more preferably in the range of 1 to 5 parts by weight with respect to 100 parts by weight of the inorganic solid content in the slurry. .

Examples of the method for coating the platinum material with the slurry-form coating material in the present invention include a method in which the slurry is applied to the surface of the platinum material and then fired. After the slurry is applied to the surface of the platinum material, it is preferably dried at a temperature of 40 to 95 ° C., for example. Further, the slurry may be applied while heating the platinum material. The slurry is preferably applied by spraying.

[0014] In the present invention, the firing temperature when the coating material is applied to the surface of the platinum material and then fired is preferably within a temperature range of 1200 ° C to 1600 ° C. When firing using the environmental temperature at which the platinum material is used, the use temperature is the firing temperature. For example, in the case of a platinum material used in a glass manufacturing apparatus, the platinum material member is heated by molten glass that passes through the inside of the member formed from the platinum material, so the coating material layer applied to the surface of the platinum material is Baking at that temperature.

[0015] The coating fired film in the first embodiment of the present invention is obtained by applying a coating material containing alumina particles, a glass component, colloidal silica, or further silica particles to the surface of the platinum material and then firing the coating material. It can be obtained from Yuko. Since colloidal silica is used as at least a part of silica, colloidal silica shows a role as an inorganic binder. For this reason, the coating fired film of the first embodiment can be formed as a dense fired film. Therefore, it can be set as the film excellent in hydrogen impermeability, and generation | occurrence | production of the bubble in glass at the time of glass manufacture can be reduced effectively. In applications where hydrogen impermeability is required, it is particularly preferable to form the fired coating film of the first embodiment. Moreover, the volatilization loss of platinum can be effectively reduced.

[0016] Since colloidal silica is a fine particle, it must be distinguished from a glass component after firing. Will not be possible and will disappear in the glass component. Therefore, in such a fired film, alumina particles are dispersed as a dispersed phase in a matrix phase having both glass component and colloidal silica component forces. When silica particles are contained in the coating material, the silica particles are dispersed as a dispersed phase together with the alumina particles.

[0017] The thickness of the fired coating film according to the first embodiment of the present invention is preferably 100 to 1000 m, more preferably 200 to 1000 m, still more preferably 500 to 1000; ζ; η is there. If the coating fired film becomes too thin, hydrogen shielding properties may be insufficient. On the other hand, if the thickness of the coating fired film is too thick, an effect proportional to the thickness cannot be obtained, which is economically disadvantageous.

[0018] The average particle diameter of the alumina particles used in the present invention is preferably in the range of 1 to: LOO / zm, and more preferably in the range of 3 to 80m. When silica force particles are used as silica, the average particle diameter is preferably in the range of 1 to L00 μm, and more preferably in the range of 3 to 80 m. If the average particle size is too large, a dense film may not be obtained even if it contains a glass component. If the average particle size is too small, the role as a filler that gives strength to the coating may be lost.

[0019] When colloidal silica is used as the silica, the average particle size is preferably in the range of 10 to 100 nm, more preferably in the range of 10 to 50 nm, and still more preferably in the range of 10 to 30 nm. It is. As described above, colloidal silica serves as an inorganic binder in the coating material, and a denser film can be formed by using colloidal silica.

[0020] The glass component used in the present invention is not particularly limited, but when applied to an apparatus for producing alkali-free glass, it is desirable that the glass component be alkali-free. This is because, even if cracks occur in the platinum device, it is an absolute requirement that the alkali component does not enter the glass (product) inside the device, so the glass component constituting the coating material is also preferably alkali-free. Because. In the present invention, “alkali-free” means that the content of the alkali component is 0.1% by weight or less. Examples of such glass components include borosilicate glass and aluminoborosilicate glass.

[0021] In the present invention, the glass component, alumina, and silica are preferably contained or contained. The amount, the glass component 20 to 70% by weight on a solids basis, of alumina 15-55% by weight, a silica force 10-50 wt ^_0/0, the glass component 30 to 70 weight ^_0/0, alumina 15-45 wt ^_0/0, more preferably in the range of silica force 10 to 30 wt%. In addition, also when using colloidal silica, it is preferable that the total amount of a silica component is the same content as the above.

[0022] The content of each component in the coating material has a preferable range depending on the use temperature at which the coating material is used. As will be described later, the temperature at which the white metal material is used in the glass manufacturing facility can be broadly divided into three temperature ranges of 1000 to 1250 ° C, 1250 to 1450 ° C, and 1450 to 1600 ° C. The temperature area of 1000 to 1250 ° C, the glass component 35 to 70% by weight (preferably 40 to 65 weight ^_0/0), alumina component 10-40% by weight (preferably 15 to 35% by weight), silica component 10 The content is preferably ˜50 wt% (preferably 10 to 30 wt%, more preferably 15 to 25 wt%). In the temperature range of 1 250 to 1450 ° C, the glass component is 20 to 60% by weight (preferably 25 to 45% by weight), the alumina component is 20 to 60% by weight (preferably 30 to 55% by weight), the silica component The content is preferably 10 to 50% by weight (preferably 10 to 30% by weight, more preferably 15 to 25% by weight). 1450-1600 The temperature range of ° C, the glass component 15 to 40 wt% (good Mashiku 15 to 35 weight ^_0/0), alumina component 35-70 weight ^_0/0 (preferably 40 to 65 weight ^_0/0 ), silica component 10 to 50% by weight (preferably 10 to 30 wt%, more preferably preferably be a content of 15-25 by weight ^_0/0),.

[0023] Preferably, according to the present invention, the coating material of the second embodiment uses silica particles as silica. Other glass components and alumina components can be the same as those in the first embodiment.

The coating material of the second embodiment according to the present invention may be in the form of a slurry, or may be in the form of a paste or a green sheet. By using a paste or green sheet, a thick film can be formed.

[0024] In the second embodiment according to the present invention, alumina particles, silica particles, and glass components may be mixed in advance and sintered. That is, a coating material may be produced using a pulverized product obtained by pulverizing a sintered body of a mixture of alumina particles, silica particles, and a glass component. [0025] The paste or green sheet in the second embodiment of the present invention includes alumina particles, silica particles, and a glass component. As described above, it may include a pulverized product obtained by pulverizing a sintered body of a mixture obtained by premixing these particles.

The paste or green sheet in the second embodiment according to the present invention preferably contains fibrous alumina particles (alumina fibers) as alumina particles. By including such an alumina fiber in the paste or the green sheet, cracking or the like occurs in the fired film after the paste or the green sheet is attached to the surface of the platinum material and fired. The content of the alumina fiber is preferably in the range of 0.1 to 30% by weight in the solid content of the paste or green sheet. As an alumina fiber, A10 is 50% by weight or more, preferably 70% by weight or less.

twenty three

The fiber length is 0.1 to 100 mm, preferably 1 mm to 50 mm, and the fiber diameter is 0.1 μm to 50 μm, preferably 1 to 20 μm. Glass with low heat resistance when Al 0 is less than 50% by weight

twenty three

It reacts easily with the ingredients, and the effect of adding fibers cannot be expected. When the fiber length is less than 0.1 mm, it is not different from particles, and when it is longer than 50 mm, it is difficult to mix uniformly. With respect to the fiber diameter, heat resistance cannot be expected at less than 0 Λ μm, and uniform dispersion is difficult at 50 m or more.

[0026] The paste or green sheet of the second embodiment according to the present invention may contain a water-soluble polymer such as methylcellulose as an organic binder. The content of the organic binder is preferably in the range of 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the inorganic solid content in the paste or green sheet. Within the scope of the part.

The coating material of the second embodiment of the present invention may be in the form of a slurry. Such a slurry is a slurry containing a mixture of alumina particles, silica particles, and glass components.

[0027] The coating method according to the second embodiment of the present invention is characterized in that the coating material according to the second embodiment of the present invention described above is baked after being applied or applied to the surface of the platinum material. It is said.

The conditions such as the firing temperature are the same as in the first embodiment.

[0028] The fired coating film according to the second embodiment of the present invention is the second embodiment of the present invention. It is characterized in that it is obtained by applying or applying the coating material of the embodiment to the surface of the platinum material, followed by baking.

The fired coating film according to the second embodiment of the present invention generally has a form in which alumina particles and silica particles are dispersed as a dispersed phase in a matrix phase composed of a glass component. FIG. 1 is a schematic diagram showing a coating fired film according to the second embodiment of the present invention. Fig. 1 (a) shows a fired film fired at a relatively low temperature of about 1300 ° C. Alumina particles and silica particles are dispersed in a matrix having glass component strength. Fig. 1 (b) shows a fired film fired in a high temperature region exceeding 1500 ° C. The dispersed alumina particles and silica particles are partially dissolved in the matrix phase. It is a silica-rich glass component. This improves the thermal stability of the matrix phase, and this coating material is flexible at high temperatures of 1500 ° C or higher, and covers the substrate in a good state without causing deformation or sagging. can do.

[0029] The thickness of the coating fired coating formed using the paste or the green sheet according to the second embodiment of the present invention is preferably in the range of 1 to: LOmm, more preferably 2 to The range is 5mm. Further, the thickness of the coating fired film when formed using the slurry is the same as in the case of the first embodiment.

In a third preferred embodiment according to the present invention, a slurry coating material layer is formed on the surface of a platinum material by applying the slurry in the first embodiment of the present invention, and on the slurry coating material layer, A protective coating material layer is formed by pasting a paste or a green sheet according to the second embodiment of the present invention.

[0030] The coating method according to the third embodiment of the present invention is characterized in that a slurry coating material layer is formed as described above, a protective coating material layer is formed thereon, and then fired. Firing conditions such as the firing temperature are the same as in the first embodiment of the present invention. The thickness of the portion of the slurry coating layer (slurry coating fired layer) in the fired coating film according to the third embodiment of the present invention is preferably in the range of 100 to 1000 m, more preferably 200 to 1000 m. It is a range, More preferably, it is the range of 500-1000 m. Also, the protective coating layer part (protective coating baking The thickness of the layer) is preferably in the range of 1 to: LOmm, more preferably in the range of 2 to 5 mm.

[0031] The fired slurry coating fired layer according to the third embodiment of the present invention is, for example, in a state where alumina particles are dispersed as a dispersed phase in a matrix phase having a glass component and colloidal silica component force. Further, the fired protective coating fired layer is, for example, in a state where alumina particles and silica particles are dispersed as a dispersed phase in a matrix phase having a glass component force.

The coating fired film according to the third embodiment of the present invention has a slurry coating fired layer similar to the coating fired film according to the first embodiment of the present invention, on which the film thickness is protected. A coating fired layer is provided. Since the slurry coating fired layer that directly covers the platinum material is the same as the fired film of the first embodiment of the present invention, it is excellent in hydrogen impermeability and generates bubbles in the glass during glass production. Can be effectively reduced. In addition, since the protective coating fired layer covering it is a thick coating fired film, it can effectively protect the platinum material in a high temperature environment and suppress the volatilization loss of platinum.

[0032] Firing conditions such as a firing temperature during firing are the same as firing conditions such as the firing temperature of the first embodiment, and firing is performed by placing a protective coating material layer on the slurry coating material layer. After the formation, the slurry coating material layer and the protective coating material layer are preferably fired simultaneously.

In the third embodiment of the present invention, the slurry coating material layer and the protective coating material layer are formed so that the ratios of the glass component, the silica component, and the alumina component are substantially the same. It's done! But it's different!

[0033] The fourth embodiment according to the present invention has a two-layer structure including a first coating layer in contact with a platinum material and a second coating layer on the first coating layer. Laminar force The layer is made of a mixture of alumina and silica, and the second coating layer is made of a glass component.

The coating fired film of the fourth embodiment of the present invention can be obtained by firing the coating material layer having the above two-layer structure. Firing conditions such as the firing temperature are the same as in the first embodiment. The fired coating film of the fourth embodiment is mainly used in a high temperature environment. It is provided for the purpose of suppressing platinum volatilization loss. The mixture of alumina and silica, which is the first coating layer, exhibits a basic function as a coating material, and coats the platinum material as a base material without being damaged even in a high temperature environment. The second coating layer, which has a glass component force, further covers the first coating layer to completely block the base material from the outside air, and has flexibility even at high temperatures. Covering and holding the coating layer of 1 suppresses peeling of the first coating layer.

FIG. 2 is a schematic diagram showing a fired coating film according to the fourth embodiment of the present invention. As shown in Fig. 2 (a), at a firing temperature of about 1300 ° C, the two-layer structure is maintained and the substrate is coated. However, as shown in FIG. 2 (b), when the temperature exceeds 1500 ° C., the first coating layer and the second coating layer react to form a single coating layer rather than a two-layer structure. Thereby, it becomes a layer which also has the glass component power with high alumina concentration and silica concentration.

[0035] According to the fourth embodiment of the present invention, the composition of each coating layer is as follows. The mixed layer of alumina and silica (first coating layer) is 15 to 88% by weight of alumina, and silica is 12 to 85. It is preferable to use weight%. If the alumina exceeds 88% by weight, defects tend to occur when the reaction with the glass phase occurs at a high temperature of 1500 ° C or higher, and if the silica exceeds 85% by weight, peeling tends to occur due to a decrease in the thermal expansion coefficient. Because. On the other hand, the glass component layer (second coating layer) may be composed of one kind of glass, or may be a mixture of plural kinds of glass. The amount of the glass serving as the second coating layer is preferably about 1: 1 with respect to the mixed layer of alumina and silica. When the glass phase is excessive, an excess glass component is produced when reacting in a high temperature environment, and there is a possibility that the excess glass component may cause sagging.

[0036] The thickness of each layer is 50 to 500 111, particularly 50 to 250 / z m for the first coating layer! /. Further, the second coating layer is preferably 50 to 500 111, particularly 50 to 250 / ζ πι. If the total thickness of the first and second coating layers is less than 100 m, it may not be a dense film necessary to prevent acidification, and if it exceeds 1000 m, peeling occurs when a significant temperature fluctuation occurs. 'This is because the possibility of dropping out increases.

[0037] As described above, the coating material of the present invention contains alumina, silica, and a glass component as essential components. In addition to these components, if necessary, zirconia, titer, It may contain other ceramic components such as mites. In the present invention, the platinum material used as the base material is not limited to pure platinum, and can be applied to a white metal alloy. Examples of platinum alloys include platinum rhodium alloys, platinum gold alloys, platinum palladium alloys, platinum iridium alloys, and platinum-ruthenium alloys. The coating material of the present invention can be applied not only to solid solution alloys but also to particle dispersion strengthened platinum alloys called reinforced platinum.

[0038] The platinum material of the present invention is coated with or coated with the coating material according to the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment of the present invention. A platinum material made of platinum or a platinum alloy, characterized in that a fired film is formed on the surface. The platinum material coated with the coating material indicates the platinum material in a state before being baked after being coated by applying or pasting the coating material. The platinum material with the coating fired film formed on the surface indicates the white metal material after the coated coating material is fired.

[0039] The glass manufacturing apparatus of the present invention is coated with a coating material according to the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment of the present invention, or the coating. A glass manufacturing apparatus characterized in that a platinum material on which a fired film is formed is used as a constituent material. Similarly to the above, a glass manufacturing apparatus using a platinum material coated with a coating material as a constituent material shows a state before the coating material is fired, and the platinum material on which the coating fired film is formed is used as the constituent material. The glass manufacturing apparatus shows the state after firing the coating material.

[0040] According to the present invention, excellent high temperature characteristics can be maintained without causing platinum volatilization loss even in a high temperature environment of 1000 ° C or higher.

Moreover, according to this invention, generation | occurrence | production of the bubble at the time of glass manufacture can be reduced. Brief Description of Drawings

[0041] [FIG. 1] FIG. 1 schematically shows a fired coating film of one example according to the second embodiment of the present invention.

FIG. 2 is a diagram schematically showing a coating fired film of one example according to the fourth embodiment of the present invention.

FIG. 3 is a diagram showing an example of the apparatus configuration of a glass manufacturing apparatus. FIG. 4 is a diagram showing an interfacial foam state of Example 6.

FIG. 5 is a diagram showing an interfacial foam state of Comparative Example 2.

FIG. 6 is a diagram showing an interfacial foam state of Comparative Example 3.

FIG. 7 is a diagram showing an interfacial foam state of Comparative Example 4.

Explanation of symbols

[0042] 1 ... Glass manufacturing equipment

2 ... dissolution tank

3 ... Kyosei tank

4 ... Agitating tank

5 ... Molding equipment

6, 7, 8… Communication channel

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, examples according to the present invention will be described together with comparative examples.

(Examples 1 to 4 and Comparative Example 1)

This example is an example using a coating material in the form of a slurry according to the first embodiment of the present invention.

[0044] Here, a coating material (fired film) in which a glass component is used as a matrix phase and alumina and silica are dispersed as a dispersed phase is produced on a platinum alloy substrate, and whether or not there is volatilization loss of platinum from the substrate It was investigated. In this embodiment, four types of coating materials having different contents of each component were manufactured. First, a raw material sol (slurry) according to the composition of the coating material to be manufactured was manufactured.

[0045] The alumina and silica used in the raw material sol (slurry) were in a deionized colloidal solution (alkali-free) state (colloidal silica). The alumina and silica used as the dispersed phase are preferably those in which at least one of alumina and silica is derived from a colloidal solution as in this embodiment. On the other hand, the glass component, Nippon Electric Glass Co., Ltd. alkali Freer luminometer borosilicate glass (material name OA- 10 Composition (wt ^{_{0/0): SiO 60%}} , BO 10%, A

2 2 3

1 O 15%, CaO

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[0046] 5%, SrO 5%, BaO 2%) and alkali-free alumino manufactured by Nippon Electric Glass Co., Ltd. Borosilicate glass (Material name: EF composition (weight./.): SiO 55%, BO 6%, A1 0 14%,

2 2 3 2 3

CaO + MgO 24% was used. The raw material sol (slurry) is produced by suspending a colloidal solution of glass, alumina, and silica in water twice the weight of the solid, and adding 3% by weight of methyl cellulose to the solid weight. And stirred to obtain a raw material sol.

[0047] A flat plate of Pt—10 wt% Rh alloy was used as a test piece as a base material (dimension: 75 mm port X 1.

Omm) ₀ And the back surface force ^ The raw material sol was supplied to the spray nozzle while stirring with a stirrer while heating with a hot air gun, and the sol was repeatedly sprayed on the test piece to a thickness of 200 / zm. After coating the sol on both sides, it was fired at 1300 ° C in an electric furnace to produce a coating material (fired coating).

[0048] The test piece on which the coating material (fired film) was formed was examined for the presence or absence of platinum volatilization loss. This examination was performed by heating the test piece in the open air at 1300 ° C and 1500 ° C for 100 hours and measuring the weight change after heating. The results are shown in Table 1. Table 1 also shows the test results of Pt—10 wt% Rh alloy with the coating material (firing film) formed.

[0049] [Table 1]

From Table 1, it was confirmed that the platinum alloy coated with the coating material (baked film) formed in each example did not cause platinum loss and had an excellent protective action. This is the same even at a high temperature of 1500 ° C or higher. On the other hand, platinum alloys not coated with a coating material (fired coating) produced a platinum loss of 0.1 lg or more at both 1300 ° C and 1500 ° C, and the amount increased with increasing temperature. It was. [0051] (Example 5)

This example is an example according to the fourth embodiment of the present invention.

Here, a two-layer coating material (fired film) was produced. First, as the first coating layer, a raw material sol (slurry) containing alumina and silica was applied onto a substrate (alumina 53.1 wt%, silica 46.9 wt%). The solvent of the raw material sol here and the adjusting method were the same as in Examples 1 to 4, and only the blending amount was adjusted. Moreover, the application | coating method was performed by spray application like Examples 1-4. Then, after applying the sol, it was dried and fired to form a first coating layer (thickness 150 πι).

[0052] After forming the first coating layer, a second coating layer was formed thereon. This second coating layer was a glass component layer containing 50% by weight of OA-10 and EF (both manufactured by Nippon Electric Glass Co., Ltd.) as glass components. The second coating layer was formed by sol spraying as described above, and the film thickness was 150 / zm.

About the test piece which formed the above coating material (baking film), the presence or absence of the volatilization loss of platinum was examined by the same method as Examples 1-4. The results are shown in Table 2.

[0053] [Table 2]

[0054] From Table 2, as in Examples:! To 4, it was confirmed that platinum alloy coated with a coating material (baked film) did not cause platinum loss. It was confirmed that this coating material (baked film) was changed to a single layer at a force of 1500 ° C, which maintained a two-layer structure at 1300 ° C. However, it was confirmed that the protective effect was not lost even at 1500 ° C.

[Example 6 and Comparative Examples 2 to 4]

This example is an example according to the first embodiment of the present invention.

Prepare slurry to have the composition of glass components, Al 2 O, SiO, and ZrO shown in Table 3. did. As the glass component, OA-10 (average particle size 7 m) is used, and as Al O,

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Lumina particles (average particle size 50 m) are used. As SiO, colloidal silica (silica

2

Lloyd solution: average particle diameter 20nm), ZrO as Zircoyu particles (average particle diameter)

2

6 m) was used. A slurry was prepared by suspending in water twice the weight of the solid and adding 3% by weight of methylcellulose to the weight of the solid.

[0056] [Application of slurry to platinum crucible]

With the inner surface of a sandblasted platinum crucible (diameter 46 mm, height 40 mm) heated with a hot air gun, slurry was applied to the bottom and outside sides of the platinum crucible by spray coating. The side was applied up to a height of 25 mm from the bottom.

After drying at 80 ° C., the platinum crucible was fired at 1500 ° C. for 5 hours to fire the coating material layer. The thickness of the coating fired film was 500 m.

[0057] [Interface foam test]

After firing the above coating material, aluminoborosilicate glass (OA-10) was filled in a platinum crucible with the temperature lowered to 1300 ° C, and the temperature was raised to 1500 ° C at a rate of 10 ° CZ. did. Hold at 1500 ° C for 1 hour.

In the platinum crucible, the interface foaming state was evaluated with ○ indicating that foaming was hardly observed, and X indicating that foaming was observed, and the evaluation results are shown in Table 3.

[0058] Figs. 4 to 7 show photographs of the foamed state of the glass in the platinum crucible. 4 shows Example 6, FIG. 5 shows Comparative Example 2, FIG. 6 shows Comparative Example 3, and FIG.

[0059] [Table 3]

[0060] As is apparent from the results shown in Table 3 and FIGS.

Example 6 containing soot and SiO as essential components contained only Al 2 O in the glass.

2 3 2 2 3

Comparative example 2, comparative example 3 containing only SiO in the glass component, and glass It can be seen that foaming can be remarkably reduced as compared with Comparative Example 4 containing ZrO. This shows that it is necessary to contain alumina and silica as essential components in accordance with the present invention in order to reduce foaming during glass production.

Moreover, the coating material of this example was able to reduce the volatilization loss of platinum as in Examples 1-5.

[0061] (Examples 7 to 9)

Slurry solutions having the compositions of Examples 7 to 9 shown in Table 4 were prepared. Glass component, Al O and

As the SiO, the same one used in Example 6 was used.

[Application of coating material to platinum crucible]

In the same manner as in Example 6, spray the above slurry on the bottom and outside sides of the platinum crucible while the inner surface of the sand crucible platinum crucible (diameter 46 mm, height 40 mm) is heated by hot air gun. Painted. After coating so that the film thickness after firing was 500 / zm, it was dried at 80 ° C to form a slurry coating material layer.

[0062] The platinum crucible on which the slurry coating material layer was formed as described above was fired at the test temperature for 5 hours, and then lowered to a temperature 200 ° C lower than the test temperature, and then aluminoborosilicate glass (OA-10). ) Was filled in a platinum crucible, and in Examples 7 to 9, the temperature was raised to the test temperature shown in Table 4 at a rate of temperature rise of 10 ° CZ, and then held at each test temperature for 1 hour. Table 4 shows the interfacial foaming at this time.

[0063] [Table 4]

As is clear from the results shown in Table 4, according to the present invention, in Examples 7 to 9 in which a coating material containing Al 2 O and SiO as essential components was applied to the glass component, Foaming can be reduced. Also, as shown in Table 4, the operating temperature range As the area increases, the glass component is decreased and the alumina component is increased, whereby heat resistance that can withstand a high operating temperature range can be imparted to the coating material. The coating material of this example was able to reduce the volatilization loss of platinum as in Examples 1-5.

[Example 10]

This example is an example using a paste-form coating material according to the second embodiment of the present invention.

As shown in Table 5, 37.5 wt ^_0/0 glass component (OA- 10), 39. 0 weight ^_0/0 of alumina (Al O) particles, and 23.5 wt% of silica (SiO) particles First, mix these

2 3 2

A sintered product of the product was prepared. As the silica particles, those having an average particle diameter of 20 m were used, and as the alumina particles, those used in Example 6 were used. The sintering condition was 1500 ° C for 24 hours, and the obtained sintered body was pulverized to obtain a pulverized product having an average particle size of about 20 m.

[0066] For 100 parts by weight of the pulverized product obtained, alumina fiber (97 wt% A1 O-3 wt%

twenty three

% SiO, average fiber length 10 mm, average fiber diameter 3 m)

2

A paste was prepared by adding and mixing to a solution of 9% by weight of rosin rosin. The proportion of the aqueous methylcellulose resin solution was 40 parts by weight with respect to 100 parts by weight of the total of the pulverized product and alumina fiber.

[0067] [Attaching paste to platinum crucible]

The paste was applied to the outer bottom surface and the outer side surface of a sandblasted platinum crucible (diameter 46 mm, height 40 mm). The position where the paste was applied was the same as in Example 6. After pasting the paste, it was fired at 1500 ° C for 5 hours. After firing, the temperature was lowered to 1300 ° C. At this temperature, the platinum crucible was filled with aluminoborosilicate glass (OA-10), and then the temperature was raised. The temperature was raised to 1500 ° C at a temperature rate of 10 ° CZ and held at 1500 ° C for 1 hour. The interfacial foaming state at this time was evaluated and shown in Table 5.

[0068] [Table 5] Difficult example 10

OA-10 (powder) 35.7wt% (37.5 t%)

A Os (powder) 37.1wt% (39.0wt%)

Si0 ₂ (powder) 22.4wt% (23.5wt%)

97% Al20 ₃ -3% Si0 ₂ (Alminaf Λ '-) 4.8wt% (5.0wt%)

100wt% (105wt%)

Interfacial foaming state 〇

[0069] As shown in Table 5, it can be seen that also in Example 10 using the paste-type coating material according to the second embodiment of the present invention, foaming during glass production can be reduced. In addition, the paste of this example was not cracked after firing. Further, as in Example 15, the volatilization loss of platinum could be reduced.

[0070] (Example 11 13)

This example is an example according to the third embodiment of the present invention.

[Preparation of slurry-form coating material]

As shown in Table 6, OA-10 is used as the glass component, and alumina particles are used as Al O.

twenty three

A slurry-like coating material was prepared using colloidal silica as SiO. Na

2

The same alumina particles and colloidal silica as in Example 6 were used. The numbers in parentheses shown in the column of colloidal silica in Table 6 are the blending ratio of colloidal silica as a solution. As organic Indah, a 1.5 wt ^_0/0 aqueous solution of methyl cellulose榭脂, used at the mixing ratio shown in Table 6, were prepared three kinds of slurries al bl and cl.

[0071] [Table 6]

(Preparation of paste)

Mix the glass component (OA-10), Al 2 O and SiO in the proportions shown in Table 7, and mix the mixture 15

2 3 2

Sintering was performed at 00 ° C. for 24 hours, and the obtained sintered body was pulverized to prepare sintered pulverized products a2 b2 and c2. [0073] [Table 7]

[0074] Next, as shown in Table 8, the obtained sintered compact was mixed with an organic binder and an aluminum naphtha to prepare three types of pastes a3, b3 and c3.

[0075] [Table 8]

[Applying coating material to platinum crucible]

Sand blasted platinum crucible (diameter 46mm, height 40mm) with the inner surface heated by hot air gun, on the bottom and outer sides of the platinum crucible, the slurry-like coating materials shown in Table 6 al, bl And cl were spray-coated and then dried at 80 ° C. to form a slurry coating material layer.

Next, pastes a3, b3 and c3 shown in Table 8 were applied onto the slurry coating material layer formed as described above, and then dried to form a protective coating material layer.

[0077] Next, the platinum crucible on which the slurry coating material layer and the protective coating material layer were formed as described above was heated to the respective test temperatures at a heating rate of 10 ° CZ, and the temperature was maintained for 5 hours. The slurry coating material layer and the protective coating material layer were baked by holding. In addition, the thickness of the slurry coating fired layer of the fired coating obtained in each example was 500 m, and the thickness of the protective coating fired layer was 5 mm.

The platinum crucible of Examples 11 to 13 having the coating fired film formed as described above. Is filled with aluminoborosilicate glass (OA-10) with the temperature lowered to 200 ° C lower than the test temperature, then heated up to the test temperature at a heating rate of 10 ° CZ, and then at each test temperature. Hold for 1 hour. Table 9 shows the state of interfacial foaming.

[0078] [Table 9]

[0079] As can be seen from the results shown in Table 9, in Examples 11 to 13 according to the third embodiment of the present invention, it can be seen that foaming during glass production can be reduced.

[0080] <Application example to glass manufacturing equipment>

Next, description will be made on examples of the glass manufacturing equipment to which the present invention is applied and a method for manufacturing glass for display using this apparatus. First, the configuration of the glass manufacturing facility will be described. FIG. 3 is an explanatory diagram showing the configuration of the glass manufacturing facility.

The glass production facility 1 includes a substantially rectangular melting tank 2 serving as a molten glass supply source, a clarification tank 3 provided on the downstream side of the dissolution tank 2, and a stirring tank 4 provided on the downstream side of the clarification tank 3. And a molding device 5 provided on the downstream side of the stirring tank 4, and the dissolution tank 2, the clarification tank 3, the stirring tank 4, and the molding apparatus 5 are connected by communication channels 6, 7, and 8, respectively. Has been.

[0081] The dissolution tank 2 has a bottom wall, a side wall, and a ceiling wall, and each of these walls is formed of a refractory material. The dissolution tank 2 is provided with a burner, an electrode, etc., and can melt the glass raw material. An outlet is formed on the downstream side wall of the dissolution tank 2, and the dissolution tank 2 and the clarification tank 3 communicate with each other via a narrow communication channel 6 having the outlet at the upstream end. ing.

The clarification tank 3 has a bottom wall, a side wall, and a ceiling wall. The inner wall surface of the bottom wall and the side wall (at least the inner wall surface part in contact with the molten glass) is made of platinum or a platinum alloy, A protective refractory is installed outside. In the clarification tank 3, the downstream end of the outflow passage 6 is open on the upstream side wall. This clarification tank 3 is a part where glass clarification is mainly performed, and fine bubbles contained in the glass are expanded and floated by the clarification gas released from the clarifier, and are removed from the glass. An outlet is formed on the downstream side wall of the clarification tank 3, and the stirring tank 4 communicates with the downstream side of the clarification tank 3 via a narrow communication channel 7 having the outlet at the upstream end.

[0083] The stirring vessel 4 has a bottom wall, a side wall, and a ceiling wall. The inner wall surface of the bottom wall and the side wall (at least the inner wall surface part in contact with the molten glass) is made of platinum or a platinum alloy, and a protective refractory is installed on the outside. The stirring tank 4 is a part where the molten glass is stirred mainly by a stirrer or the like and homogenized.

An outflow port is formed on the downstream side wall of the stirring tank 4, and the molding device 5 communicates with the downstream side of the stirring tank 4 through a narrow communication channel 8 having the outflow port at the upstream end.

[0084] As the forming apparatus 5, for example, in the case of forming display glass, a plate glass forming apparatus such as a downdraw forming apparatus, an updraw forming apparatus, or a float forming apparatus is used. Particularly in the case of liquid crystal glass, an overflow downdraw apparatus is suitable.

In addition, the communication channel 6 connecting the dissolution tank 2 and the clarification tank 3 is formed of a refractory, while the other communication channel, that is, the connection connecting the clarification tank 3 and the stirring tank 4 is used. The flow path 7 and the communication flow path 8 that connects the stirring tank 4 and the molding device 5 are formed of platinum or a platinum alloy, and a protective refractory is installed on the outside thereof.

In this example, the glass according to the third embodiment of the present invention is formed on the outer surface of a glass production facility (here, clarification tank 2 to communication channel 8) made of platinum or a platinum alloy in the production facility. A coating firing film in which a protective coating fired layer was formed on a single coating fired film, that is, a slurry coating fired layer was formed. As such a coating baked film, for example, the coating materials of Examples 11 to 13 can be suitably used.

[0086] A method for producing display glass using the glass production equipment having the above-described configuration is as follows.

First, a glass raw material is prepared. For example, SiO -A1 O -B O— RO (RO is MgO

2 2 3 2 3, one or more of CaO, BaO, SrO and ZnO) In terms of mass percentage, SiO 50-70%, Α1 Ο 10-25%, BO 5-20%, MgO

2 2 3 2 3

To be an alkali-free glass containing 0-10%, CaO 3-15%, BaO 0-10%, SrO 0-10%, ZnO 0-10%, TiO 0-5%, PO 0-5% Glass raw materials

2 2 5

Mix. In addition to the above, various components such as a fining agent can be added.

[0087] Subsequently, the glass raw material thus prepared is put into the melting tank 2 and melted and vitrified. In the melting tank 2, the glass is heated upward by the burner flame. Above SiO -A1 O -B O

2 2 3 2 3

—In the case of RO glass, the glass is melted at 1500-1650 ° C.

The molten glass vitrified in the melting tank 2 is guided to the clarification tank 3 through the communication channel 6. The molten glass contains initial bubbles generated during the vitrification reaction. In the clarification tank 3, the initial bubbles are lifted and removed by the clarified gas released by the fining agent component force.

[0088] The molten glass clarified in the clarification tank 3 is guided to the stirring tank through the communication channel 7. In the stirring tank 4, the glass is stirred and homogenized by a rotating stirrer.

The molten glass homogenized in the stirring vessel 4 is guided to the forming device 5 through the communication channel 8 and formed into a plate shape. In this way, a display glass can be obtained.

[0089] In general, the communication channel 6 from the dissolution tank 2 to the clarification tank 3 corresponds to the operating temperature range of 1450 ° C to 1600 ° C, and the communication flow from the clarification tank 3, the clarification tank 3 to the stirring tank 4 The passage 7 and the stirring tank 4 correspond to the working temperature range of 1250 ° C to 1450 ° C, and the stirring tank 4 and the connecting flow path 8 to the forming device 5 are the working temperature of 1000 ° C to 1250 ° C. Corresponds to the area.

In the glass manufacturing apparatus of this example, when the above-described glass manufacturing method was performed, the volatilization loss of platinum was suppressed even after the apparatus was operated for a long time. As a result, the strength and stability of the manufacturing equipment were maintained for a long time. In addition, the generation of bubbles during glass production could be reduced. Note that the apparatus according to the present embodiment is naturally applicable to the manufacture of glass other than display glass.

Claims

The scope of the claims

[I] Platinum or platinum alloy power A material for coating the surface of platinum material.

A coating material for a platinum material containing a refractory material component containing alumina and silica and a glass component.

[2] The coating material for a platinum material according to [1], wherein the glass component is an alkali-free borosilicate glass or aluminoborosilicate glass.

[3] The content of alumina, silica, and glass component is 15 to 55% by weight of alumina, 10 to 50% by weight of silica, and 20 to 70% by weight of glass component. One timber.

[4] The coating material for platinum material according to any one of claims 1 to 3, wherein the coating material is colloidal silica.

[5] The coating material for a platinum material according to [4], comprising alumina particles, a glass component, and colloidal silica.

6. The coating material for a platinum material according to claim 4, comprising a pulverized product obtained by pulverizing a sintered body of a mixture of alumina particles and a glass component, and colloidal silica.

[7] The coating material for a platinum material according to any one of claims 1 to 3, wherein the slurry force includes alumina particles, a glass component, and silica particles.

[8] The coating material for a platinum material according to [5], which also has a slurry force containing alumina particles, a glass component, and colloidal silica.

[9] The coating material for a platinum material according to [6], which has a slurry force comprising a pulverized product obtained by pulverizing a sintered body of a mixture of alumina particles and a glass component, and colloidal silica.

[10] The coating material for a platinum material according to any one of [7] to [9], wherein the slurry contains an organic binder.

[II] The coating material for a platinum material according to any one of claims 1 to 3, comprising a pulverized product obtained by pulverizing a sintered body of a mixture of alumina particles, silica particles, and a glass component.

[12] The coating material for a platinum material according to any one of [1] to [3], comprising a paste or a green sheet containing alumina particles, silica particles, and a glass component.

[13] The coating material for a platinum material according to [11], comprising a paste or a green sheet containing a pulverized product obtained by pulverizing a sintered body of a mixture of alumina particles, silica particles and a glass component.

14. The coating material for platinum material according to claim 12 or 13, wherein at least part of the alumina particles are fibrous alumina particles.

[15] The paste or the green sheet contains an organic binder.

The coating material for platinum materials according to any one of -14.

[16] A method for coating a platinum material, comprising: applying or coating the coating material according to any one of claims 1 to 15 on a surface of the platinum material, followed by baking.

[17] The method for coating a platinum material according to claim 16, wherein the slurry according to any one of LO is applied to the surface of the platinum material and then baked.

18. The method for coating a platinum material according to claim 17, wherein the slurry is applied to the surface of the platinum material by spraying.

[19] The coating of the platinum material according to claim 16, wherein the paste or the green sheet according to any one of claims 12 to 15 is applied to a surface of the platinum material and then baked. Method.

[20] Claim 7-: The slurry according to any one of LO is applied to the surface of a platinum material to form a slurry coating layer, and the slurry coating layer is formed on the slurry coating layer. 17. The method for coating a platinum material according to claim 16, wherein the paste or the green sheet according to claim 1 is applied to form a protective coating layer, followed by firing.

[21] The method for coating a platinum material according to any one of [16] to [20], wherein the surface of the platinum material is blasted and then a coating material is applied or pasted thereon.

[22] A fired film for coating the surface of a platinum material made of platinum or a platinum alloy, A white metal material characterized in that it is obtained by firing after applying or applying the coating material according to any one of claims 1 to 3, 7 and 11 to the surface of the platinum material. Coating fired film.

[23] A fired film that coats the surface of a platinum material made of platinum or a platinum alloy,

A coating fired coating of a platinum material, wherein alumina particles and silica particles are dispersed as a dispersed phase in a matrix phase having a glass component force.

[24] A fired film that coats the surface of a platinum material made of platinum or a platinum alloy,

A coating fired coating of a platinum material, which is obtained by applying the coating material according to any one of claims 4 to 6 and 8 to 10 to the surface of the platinum material and then firing it.

[25] A fired film for coating the surface of a platinum material made of platinum or a platinum alloy,

A coating fired coating of a platinum material, characterized in that alumina particles are dispersed as a dispersed phase in a matrix phase that also has a glass component and colloidal silica component.

[26] A fired film for coating the surface of a platinum material made of platinum or a platinum alloy,

A coating fired coating of a platinum material, wherein the paste or green sheet according to any one of claims 12 to 15 is applied to the surface of the platinum material and then fired.

[27] A fired film for coating the surface of a platinum material made of platinum or a platinum alloy,

[Claim 7]: The slurry according to any one of LO is applied to a surface of a platinum material to form a slurry coating layer, and the slurry coating layer according to any one of claims 12 to 15 is formed on the slurry coating layer. A coating fired coating of a platinum material, which is obtained by pasting the paste or green sheet according to item 1 to form a protective coating layer and then firing.

[28] The platinum material coating according to claim 27, wherein in the slurry coating layer, alumina particles are dispersed as a dispersed phase in a matrix phase having a glass component and a colloidal silica component. Firing film.

29. The fired coating film of a platinum material according to claim 27, wherein alumina particles and silica particles are dispersed as a dispersed phase in a matrix phase having a glass component force in the protective coating layer. .

[30] A fired film for coating the surface of a platinum material made of platinum or a platinum alloy,

By baking a coating material having a two-layer structure comprising a mixture of alumina and silica, the first coating layer being in contact with the platinum material, and the second coating layer having a glass component force on the coating layer. A platinum fired coating film characterized by being obtained.

[31] A platinum material comprising platinum or a platinum alloy, characterized in that the coating material according to any one of claims 1 to 15 is coated.

[32] A platinum material comprising platinum or a platinum alloy cover, wherein the fired coating film according to any one of claims 22 to 29 is formed on a surface thereof.

[33] A glass manufacturing apparatus comprising a platinum material made of platinum or a platinum alloy as a constituent material, wherein the coating material according to any one of claims 1 to 15 is coated on the outer surface. Glass manufacturing equipment.

34. A glass manufacturing apparatus comprising a platinum material made of platinum or a platinum alloy as a constituent material, wherein the fired coating film according to claim 22 is formed on an outer surface.