KR20070053749A - Coating material for platinum material, platinum material coated with such coating material, and glass manufacturing apparatus - Google Patents

Abstract

A material for coating the surface of a platinum material made of platinum or a platinum alloy, comprising: a refractory material component containing alumina and silica and a coating material for platinum material containing a glass component.

Coating material for platinum material

Description

COATING MATERIAL FOR PLATINUM MATERIAL, PLATINUM MATERIAL COATED WITH SUCH COATING MATERIAL, AND GLASS MANUFACTURING APPARATUS}

TECHNICAL FIELD This invention relates to the coating material for coating the platinum material used under high temperature environment, such as a glass manufacturing apparatus.

A platinum material is generally used as a constituent material of an apparatus (stirring bath, dissolution tank, clarification tank, etc.) for manufacturing high quality glass such as optical glass and display glass. Platinum material is used for the constituent materials of these tower algae, because platinum has a high melting point and does not form an oxide layer in the air, and thus does not deteriorate, there is a low risk of deformation and damage during operation of the apparatus, and also excellent chemical stability. This is due to the fact that the risk of contaminating the glass in the molten state is low. In addition to platinum, platinum alloys such as platinum-rhodium alloys are widely used as the platinum material (the details of the platinum material that can be applied to the glass industry are described in the prior art column of Patent Document 1).

Although the apparatus temperature in a glass manufacturing process changes with the process content, it exists in the high temperature environment of 1200-1600 degreeC and 1000 degreeC or more. The platinum material can maintain sufficient durability for a long time without polluting the molten glass inside an apparatus even under such a high temperature environment from the said characteristic.

However, under the high temperature environment, there is one problem with respect to the behavior on the outer surface of the apparatus. This problem is that the platinum in the platinum material is lost by volatilization by generating platinum oxide (PtO ₃ ) which is a gas oxide. Volatilization loss of this platinum reaches several% of the weight of a platinum apparatus in normal use, and becomes a factor which directly deteriorates the strength and stability of a platinum material in the site | part which has a large volatilization amount locally. Moreover, since volatilized platinum adheres to the fireproof material and heat insulating material provided around the glass manufacturing apparatus, the member used as the object of platinum collection | refining refinement increases. In addition, the loss of expensive platinum material is volatilized into a space that is difficult to recover.

Moreover, in the glass manufacturing apparatus using a platinum member, there existed a problem that the bubble which originates in the moisture in glass generate | occur | produces in the interface of a platinum member at the time of glass manufacture (patent document 2 etc.). This is because water in the glass is decomposed, and hydrogen generated by decomposition passes through the platinum member and is released to the outside. As a result, glass having a high oxygen concentration exists near the interface of the platinum member, whereby oxygen bubbles are generated. It is thought to be due to.

In patent document 3, in order to solve the problem of the bubble generation at the time of said glass manufacture, forming a hydrogen-impermeable glass-based film on the outer surface of a platinum member is proposed.

However, as a result of the present inventors examining the glass-based coating disclosed in Patent Document 3, it was not possible to sufficiently reduce the generation of bubbles at the time of glass production.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-280070

Patent Document 2: Japanese Patent Application Publication No. 2001-503008

Patent Document 3: Japanese Patent Publication No. 2004-523449

Disclosure of the Invention

It is a first object of the present invention to provide a preferred material for coating a platinum material used in a high temperature environment.

The 2nd object of this invention is to provide the coating material for platinum materials which can reduce generation | occurrence | production of the bubble resulting from the moisture in glass at the time of glass manufacture.

The characteristics required for the coating material of the platinum material used at a high temperature are summarized firstly, in addition to being not melted or deformed under a high temperature environment, it is possible to follow the deformation of the platinum material as a base material with a certain degree of flexibility. need. This is because thermal expansion and contraction of the constituent materials occur during start-up and shutdown of the apparatus, and thus only hard coating materials with high strength can not follow the dimensional change, crack, generate deformation, and lose their function. . And secondly, it is necessary to have a dense film quality and a component which is hard to produce defects, such as a pinhole. The presence of a defect not only leads to damage of the coating material during use, but also causes a contact between the substrate and the outside air, and the volatilization loss of platinum from the substrate is not sufficiently suppressed.

Therefore, metal oxides and the like, which are known as general refractory materials, can be used from the standpoints of strength and stability under high temperature environments. However, since they lack flexibility and high melting points, it is difficult to form a dense film by sintering. The characteristic is not provided.

MEANS TO SOLVE THE PROBLEM The present inventors considered the structure of a preferable coating material, based on the above prerequisite conditions, As a result, it can be said that the above conditions can be provided in the material which added the glass component to the crystalline metal oxide of alumina and a silica. The idea went crazy.

In addition, it has been found that a coating material containing alumina and silica as an essential component of a refractory material and having a glass component added thereto can effectively reduce the generation of bubbles due to moisture in the glass during glass production. And reached the present invention.

That is, this invention is a material for coating the surface of the platinum material which consists of platinum or a platinum alloy, and is a coating material for platinum materials containing the refractory material component containing alumina and a silica, and a glass component.

The coating material in this invention contains an alumina particle, a glass component, a silica particle, and / or colloidal silica. Hereinafter, the technical matter common to 1st-4th embodiment which concerns on this invention may be demonstrated as "this invention."

In a first preferred embodiment according to the present invention, colloidal silica is used as at least part of the silica. Therefore, it is a coating material containing an alumina particle, a glass component, colloidal silica, and a silica particle further as needed.

In 1st Embodiment which concerns on this invention, an alumina particle and a glass component, or further, silica particle may be mixed previously. That is, it is good also as a coating material using the alumina particle, a glass component, or the silica particle further mixed, and the sintered compact which sintered this was pulverized and colloidal silica.

In 1st Embodiment which concerns on this invention, it is preferable to make a coating material into the form of a slurry. That is, it is preferable to use as a coating material the slurry containing an alumina particle, a glass component, colloidal silica, or a silica particle further. As described above, when using a pulverized product obtained by pulverizing a sintered compact of alumina particles and a glass component or a mixture of silica particles, a slurry containing the pulverized product and colloidal silica is used as a coating material.

It is preferable to contain water-soluble polymers, such as methylcellulose, as an organic binder in a slurry. As content of an organic binder, the inside of the range of 0.5-10 weight part is preferable with respect to 100 weight part of inorganic solid content in a slurry, More preferably, it exists in the range of 1-5 weight part.

As a method of coating the platinum material with the slurry form in this invention, the method of baking after apply | coating a slurry to the surface of a platinum material is mentioned. After apply | coating a slurry to the surface of a platinum material, it is preferable to dry at the temperature of 40-95 degreeC, for example. Moreover, you may apply | coat a slurry, heating a platinum material. The slurry is preferably applied by spraying.

In this invention, it is preferable to exist in the temperature range of 1200 degreeC-1600 degreeC as baking temperature at the time of baking after apply | coating a coating material to the surface of a platinum material. When baking using the environmental temperature at which a platinum material is used, the use temperature becomes baking temperature. For example, in the case of the platinum material used in the glass manufacturing apparatus, since the member of the platinum material is heated by the molten glass passing through the inside of the member formed of the platinum material, the coating material layer applied to the surface of the platinum material is kept at that temperature. Fired.

The coating baking film in 1st Embodiment of this invention is obtained by baking after apply | coating the coating material containing an alumina particle, a glass component, colloidal silica, or the silica particle further to the surface of a platinum material. 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 baking film of 1st Embodiment can be formed as a compact baking 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 the use which requires hydrogen impermeability, it is especially preferable to form the coating baking film of this 1st Embodiment. Moreover, the volatilization loss of platinum can also be reduced effectively.

Since colloidal silica is microparticles, it cannot be distinguished from a glass component after baking, and will be lost in the glass component. Therefore, in such a fired film, alumina particles are dispersed as a dispersed phase on a matrix composed of a glass component and a colloidal silica component. In addition, when silica particle is contained in a coating material, a silica particle is also disperse | distributed as a dispersed phase with an alumina particle.

It is preferable that the thickness of the coating baking film which concerns on 1st Embodiment of this invention is 100-1000 micrometers, More preferably, it is 200-1000 micrometers, More preferably, it is 500-1000 micrometers. When the film thickness of a coating baking film becomes too thin, hydrogen shielding property may become inadequate. Moreover, when the thickness of a coating baking film is made too thick, the effect in proportion to thickness will not be acquired, and it will become economically disadvantageous.

It is preferable that the average particle diameter of the alumina particle used by this invention exists in the range of 1-100 micrometers, More preferably, it exists in the range of 3-80 micrometers. Moreover, when using silica particle as a silica, the average particle diameter is preferable to exist in the range of 1-100 micrometers, More preferably, it exists in the range of 3 to 80 micrometers. When an average particle diameter becomes too large, a dense film may not be obtained even if it contains a glass component. Moreover, when an average particle diameter is too small, the role as a filler which gives strength to a film may be lost.

When colloidal silica is used as silica, it is preferable that the average particle diameter exists in the range of 10-100 nm, More preferably, it exists in the range of 10-50 nm, More preferably, it exists in the range of 10-30 nm. As described above, colloidal silica acts as an inorganic binder in the coating material, and by using colloidal silica, a more dense coating can be formed.

Although it does not restrict | limit especially as a glass component used by this invention, When applying to the manufacturing apparatus of alkali free glass, it is preferable that it is alkali free. This is because it is preferable that the glass component constituting the coating material is also alkali-free, because the absolute condition is that an alkali component will not be mixed into the glass (product) inside the apparatus even if a crack occurs in the platinum apparatus. In addition, in this invention, an alkali free means that content of an alkali component is 0.1 weight% or less. As such a glass component, borosilicate glass and alumino borosilicate glass are mentioned, for example.

In this invention, as a preferable content of each structural component of a glass component, an alumina, and a silica, it is 20-70 weight% of a glass component, 15-55 weight% of alumina, 10-50 weight% of silica, and 30-30 glass components on a solid content basis. It is more preferable that it is the range of 70 weight%, 15 to 45 weight% of alumina, and 10 to 30 weight% of silica. Moreover, also when using colloidal silica, it is preferable that the total amount of a silica component is content similar to the above.

Moreover, content of each component in a coating material has a preferable range also according to the use temperature at which a coating material is used. As mentioned later, the temperature of the point where the platinum material in a glass manufacturing apparatus is used is divided roughly into three temperature ranges of 1000-1250 degreeC, 1250-1450 degreeC, and 1450-1600 degreeC. In the temperature range of 1000 to 1250 ° C, 35 to 70% by weight (preferably 40 to 65% by weight) of glass components, 10 to 40% by weight (preferably 15 to 35% by weight) of alumina components, and 10 to 50 silica components It is preferable that it is content of weight% (preferably 10-30 weight%, More preferably, 15-25 weight%). Moreover, in the temperature range of 1250-1450 degreeC, 20-60 weight% of glass components (preferably 25-45 weight%), 20-60 weight% of alumina components (preferably 30-55 weight%), and a silica component 10 It is preferable that it is content of -50 weight% (preferably 10-30 weight%, More preferably, 15-25 weight%). In the temperature range of 1450-1600 ° C., 15 to 40% by weight of glass components (preferably 15 to 35% by weight), 35 to 70% by weight of alumina components (preferably 40 to 65% by weight), and silica components 10 to 50 It is preferable that it is content of weight% (preferably 10-30 weight%, More preferably, 15-25 weight%).

The coating material of the second preferred embodiment of the present invention uses silica particles as silica. About another glass component and an alumina component, the thing similar to said 1st Embodiment can be used.

The coating material of the second embodiment according to the present invention may be in the form of a slurry or in the form of a paste or a green sheet. By setting it as the form of a paste or a green sheet, it becomes possible to form a film with a thick film thickness.

In the second embodiment according to the present invention, the alumina particles, the silica particles, and the glass component may be mixed in advance and sintered. That is, you may produce a coating material using the grind | pulverized material which grind | pulverized the sintered compact of the mixture of alumina particle, a silica particle, and a glass component.

The paste or green sheet in 2nd Embodiment of this invention contains an alumina particle, a silica particle, and a glass component. As described above, a pulverized product obtained by pulverizing the sintered compact of the mixture obtained by mixing these particles in advance may be contained.

It is preferable that fibrous alumina particles (alumina fibers) are contained in the paste or green sheet according to the second embodiment of the present invention as alumina particles. By incorporating such alumina fibers into the paste or green sheet, cracking and the like become less likely to occur in the fired film after the paste or green sheet is adhered to the surface of the platinum material and fired. As content of an alumina fiber, it is preferable to exist in the range of 0.1-30 weight% in solid content of a paste or a green sheet. Alumina fibers include, and Al ₂ O ₃ is less than 50% by weight, preferably at least 70% by weight, the fiber length is 0.1~100㎜, and preferably 1㎜~50㎜, the fiber diameter is 0.1㎛~50㎛ Preferably it is 1-20 micrometers. Al ₂ O ₃ is less than 50% by weight, the lower the heat resistance, can not be expected the effect of the glass component and facilitate the reaction, into the fiber. The fiber length is less than 0.1 mm unchanged with the particles, and longer than 50 mm is difficult to mix uniformly. With respect to the fiber diameter, heat resistance cannot be expected at less than 0.1 m, and uniform dispersion is difficult at 50 m or more.

Moreover, you may contain water-soluble polymers, such as methylcellulose, as an organic binder in the paste or green sheet of 2nd Embodiment which concerns on this invention. It is preferable that content of an organic binder exists in the range of 0.5-10 weight part with respect to 100 weight part of inorganic solid content in a paste or a green sheet, More preferably, it exists in the range of 1-5 weight part.

The coating material of the second embodiment of the present invention may be a slurry. Such a slurry is a slurry which mixes and contains alumina particle, a silica particle, and a glass component.

The coating method according to the second embodiment of the present invention is characterized by firing the coating material of the second embodiment of the present invention after applying or adhering to the surface of the platinum material.

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

The coating baking film which concerns on 2nd Embodiment of this invention is obtained by baking after apply | coating or adhering the coating material of 2nd Embodiment of this invention to the surface of a platinum material, It is characterized by the above-mentioned.

The coating calcined 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 on a matrix made of a glass component. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the coating baking film in 2nd Embodiment of this invention. Fig.1 (a) shows the baking film baked at the comparatively low temperature of about 1300 degreeC, and alumina particle and a silica particle are disperse | distributing in the matrix which consists of a glass component. FIG. 1 (b) shows a fired film fired in a high temperature region exceeding 1500 ° C., in which alumina particles and silica particles as dispersed phases are partially dissolved in a matrix, whereby the matrix phase is rich glass of alumina and silica rich. ) Component. Thereby, the thermal stability of the matrix phase is improved, and this coating material can be coated in a good state without generating deformation or sag while having flexibility at a high temperature of 1500 ° C or higher.

It is preferable that the thickness of the coating baking film formed using the paste or the green sheet according to the second embodiment of the present invention is in the range of 1 to 10 mm, more preferably in the range of 2 to 5 mm. In addition, the thickness of the coating baking film when it forms using a slurry is the same as that of the said 1st Embodiment.

According to a third preferred embodiment of the present invention, the slurry in the first embodiment of the present invention is applied to the surface of a platinum material to form a slurry coating material layer, and on the slurry coating material layer, the second of the present invention. The paste or green sheet according to the embodiment is attached to form a protective coating material layer.

The coating method according to the third embodiment of the present invention is characterized by baking after forming a slurry coating material layer as above, forming a protective coating material layer thereon, and then baking. Firing conditions, such as a baking temperature, are the same as that of 1st Embodiment of this invention.

It is preferable that the thickness of the part (slurry-coated baking layer) of the slurry coating layer in the coating baking film which concerns on 3rd embodiment of this invention is 100-1000 micrometers, More preferably, it is the range of 200-1000 micrometers. More preferably, it is the range of 500-1000 micrometers. The thickness of the portion (protective coating calcined layer) of the protective coating layer is preferably in the range of 1 to 10 mm, more preferably in the range of 2 to 5 mm.

The slurry coating baking layer after baking in 3rd Embodiment of this invention is a state in which alumina particle is disperse | distributed as a dispersed phase on the matrix which consists of a glass component and a colloidal silica component, for example. Moreover, the protective coating baking layer after baking is a state in which alumina particle and a silica particle were disperse | distributed as a dispersed phase on the matrix which consists of glass components, for example.

The coating baking film which concerns on 3rd embodiment of this invention has the same slurry coating baking layer as the coating baking film which concerns on 1st embodiment of this invention, and forms the protective coating baking layer with a thick film on it. Since the slurry coating baking layer which coat | covers a platinum material directly is the same as the baking film of 1st Embodiment of this invention, it is excellent in hydrogen impermeability and can reduce generation | occurrence | production of the bubble in glass at the time of glass manufacture effectively. have. Moreover, since the protective coating baking layer which coat | covers it is a coating baking film with a thick film thickness, it can effectively protect the platinum material in high temperature environment, and can suppress that platinum is volatilized and lost.

The baking conditions, such as the baking temperature at the time of baking, are the same as the baking conditions, such as the baking temperature of said 1st Embodiment, and baking is a slurry coating material layer and a protective coating material after forming a protective coating material layer on a slurry coating material layer. It is preferable to fire the layers simultaneously.

Moreover, in 3rd Embodiment of this invention, each layer may be formed and may differ from the slurry coating material layer and the protective coating material layer so that the ratio of a glass component, a silica component, and an alumina component may become substantially the same.

A fourth embodiment according to the present invention has a two-layer structure consisting of a first coating layer in contact with a platinum material and a second coating layer on the first coating layer, wherein the first coating layer is made of a mixture of alumina and silica, and the second The coating layer is made of a glass component.

The coated baking film of 4th Embodiment of this invention is obtained by baking the coating material layer which has the said two-layered structure. Firing conditions, such as a baking temperature, are the same as that of the said 1st Embodiment. The coating plastic film of 4th Embodiment is formed in order to suppress the volatilization loss of platinum mainly in a high temperature environment. The mixture of alumina and silica, which is the first coating layer, exhibits a basic function as a coating material, and is not damaged even in a high temperature environment, thereby covering the platinum material as a substrate. And the 2nd coating layer which consists of a glass component is made to completely block a base material and external air by further covering a 1st coating layer, and a 1st coating layer is peeled off by covering and holding a 1st coating layer with flexibility even under high temperature. Suppress it.

It is a schematic diagram which shows the coating baking film of 4th Embodiment of this invention. As shown to Fig.2 (a), at the baking temperature of about 1300 degreeC, the two-layer structure is hold | maintained and the base material is coat | covered. However, as shown in FIG.2 (b), when it exceeds 1500 degreeC, a 1st coating layer and a 2nd coating layer will react, and it becomes a coating layer of a single layer rather than a two-layer structure. Thereby, it becomes a layer which consists of a glass component which the alumina concentration and the silica concentration became high.

In 4th Embodiment of this invention, it is preferable that the composition of each coating layer is 15-88 weight% of alumina and 12-85 weight% of alumina as a mixed layer (first coating layer) of alumina and silica. This is because if the content of the alumina exceeds 88% by weight, defects are likely to occur when the reaction with the glass phase occurs at a high temperature of 1500 ° C or higher, and when the silica exceeds 85% by weight, peeling is likely to occur due to a decrease in the coefficient of thermal expansion. On the other hand, about a glass component layer (2nd coating layer), although it may consist of one type of glass, you may apply what mixed multiple types of glass. It is preferable that the quantity of the glass used as a 2nd coating layer shall be about 1: 1 with respect to the mixed layer of alumina and a silica. It is because when a glass phase becomes excess, an excess glass component will generate | occur | produce when reacting in a high temperature environment, and sagging by this excess glass component may arise.

It is preferable that the film thickness of each layer is 50-500 micrometers, especially 50-250 micrometers with respect to a 1st coating layer. Moreover, it is preferable to set it as 50-500 micrometers, especially 50-250 micrometers about a 2nd coating layer. This is because when the first coating layer and the second coating layer are less than 100 µm, there is a possibility that the dense film necessary for the oxidation prevention may not be formed. If the thickness exceeds 1000 µm, the possibility of peeling and dropping off increases when a large temperature fluctuation occurs.

As mentioned above, although the coating material of this invention makes an alumina, a silica, and a glass component an essential component, in addition to these components, you may contain other ceramic components, such as zirconia, titania, and mullite, as needed.

There is no restriction | limiting in particular as the platinum material used as base material in this invention, It is applicable to a platinum alloy besides pure platinum. Platinum alloys include platinum-rhodium alloys, platinum-gold alloys, platinum-palladium alloys, platinum-iridium alloys and platinum-ruthenium alloys. Moreover, the coating material of this invention is applicable not only to a solid solution alloy but also to the platinum alloy of particle-dispersion strengthening type called reinforced platinum.

Platinum material of this invention is coated with the coating material concerning 1st, 2nd, 3rd, or 4th embodiment of the said invention, or the coating plastic film was formed in the surface, The platinum characterized by the above-mentioned. Or a platinum material made of a platinum alloy. The platinum material coated with the coating material represents the platinum material in a state before firing after coating or applying the coating material and coating the coating material. The platinum material in which the coating baking film was formed on the surface has shown the platinum material after baking the coated coating material.

The glass manufacturing apparatus of this invention uses the platinum material by which the coating material which concerns on the said 1st, 2nd, 3rd embodiment, or 4th embodiment of the said invention, or the coating baking film was formed as a constituent material. It is a glass manufacturing apparatus characterized by the above-mentioned. As described above, the glass manufacturing apparatus using the platinum material coated with the coating material as the constituent material shows a state before baking the coating material, and the glass manufacturing apparatus using the platinum material with the coated plastic coating as the constituent material after firing the coating material It shows the state.

According to the present invention, the platinum volatilization loss is not generated even in a high temperature environment of 1000 ° C or higher, and the excellent high temperature characteristics can be maintained.

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

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the coating baking film of the Example which concerns on 2nd Embodiment of this invention.

It is a figure which shows typically the coating baking film of the Example which concerns on 4th Embodiment of this invention.

It is a figure which shows an example of the apparatus structure of a glass manufacturing apparatus.

4 is a view showing an interfacial foaming state in Example 6. FIG.

5 is a view showing the interfacial foaming state of Comparative Example 2. FIG.

6 is a view showing an interfacial foaming state in Comparative Example 3. FIG.

7 is a view showing an interfacial foaming state in Comparative Example 4. FIG.

Explanation of the sign

1 ... glass manufacturing equipment

2 ... melting tank

3 ...

4 ...

5 ... molding machine

6, 7, 8 ... Contact euro

To practice the invention  Best form for

Hereinafter, the Example which concerns on this invention is described with a comparative example.

(Examples 1 to 4 and Comparative Example 1)

This example is an example using the coating material of the slurry form which concerns on 1st Embodiment of this invention.

Here, the coating material (baking film) which made the glass component into a matrix form, and disperse | distributed alumina and silica as a dispersed phase was manufactured on the platinum alloy base material, and the presence or absence of the volatilization loss of platinum from the base material was examined. In this embodiment, four types of coating materials having different contents of each component were produced. First, the raw material sol (slurry) according to the composition of the coating material to be manufactured was manufactured.

As the alumina and silica used for the raw material sol (slurry), one having a deionized colloidal solution (alkali-free) (colloidal silica) was used. As for alumina and a silica used as a dispersed phase, it is preferable that at least any one of alumina and a silica is derived from a colloidal solution like this embodiment. On the other hand, a glass component, the Nippon Denki sink's alkali-free alumino-borosilicate glass Co., Ltd. (material name OA-10 Composition _{(wt.%): SiO 2 60%,} B 2 O 3 10%, Al 2 O 3 15% , CaO 5%, SrO 5%, BaO 2%) and alkali-free aluminoborosilicate glass manufactured by Nippon Denki Glass Co., Ltd. (material EF composition (% by weight): SiO ₂ 55%, B ₂ O ₃ 6%, Al 14% ₂ O _{3 and} 24% CaO + MgO were used, and the preparation of the raw material sol (slurry) was carried out by suspending a colloidal solution of glass, alumina and silica in twice the weight of solid water and further methylcellulose. Was added 3% by weight based on the weight of the solid, and stirred to obtain a raw material sol.

As a base material, the flat plate of the Pt-10wt% Rh alloy was used as a test piece (dimensions: 75 mm x 1.0 mm). And the raw material sol was supplied to the spray nozzle, stirring with a stirrer, heating from a back surface with a hot air gun, and sol was repeatedly sprayed to the test piece and applied to the thickness of 200 micrometers. After the sol was applied to both sides, it was baked at 1300 ° C. in an electric furnace to prepare a coating material (plastic coating).

About the test piece in which the coating material (baking film) was formed, the presence or absence of the volatilization loss of platinum was examined. This examination was performed by heating a test piece at 1300 degreeC and 1500 degreeC in outdoor air for 100 hours, and measuring the weight change after heating. The results are shown in Table 1. In Table 1, the test result of the Pt-10wt% Rh alloy which does not form the coating material (plastic coating) is shown together.

From Table 1, platinum loss did not generate | occur | produce in the platinum alloy coat | covered with the coating material (plastic film) formed in each Example, and it was confirmed that it had the outstanding protective effect. This is the same also at high temperature of 1500 degreeC or more. On the other hand, in the platinum alloy which is not coat | covered with a coating material (plastic coating), it was confirmed that the platinum loss generate | occur | produces 0.1 g or more at both 1300 degreeC and 1500 degreeC, and the quantity increases with temperature rise.

(Example 5)

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

Here, a coating material (plastic coating) having a two-layer structure was produced. First, as a 1st coating layer, the raw material sol (slurry) containing alumina and silica was apply | coated on the base material (53.1 weight% alumina, 46.9 weight% silica). The solvent and adjustment method of the raw material sol here were the same as Examples 1-4, and only the compounding quantity was adjusted. Moreover, the coating method was implemented by spray coating similarly to Examples 1-4. And after apply | coating of a sol, it dried and baked and formed the 1st coating layer (150 micrometers in thickness).

After forming the first coating layer, a second coating layer was formed thereon. This 2nd coating layer was made into the glass component layer which contains 50 weight% of OA-10 and EF (all the Nippon Denki Glass Co., Ltd. product) as a glass component. The formation process of the 2nd coating layer was performed by spray coating of a sol similarly to the above, and the film thickness was 150 micrometers.

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

From Table 2, it was confirmed that platinum loss does not occur in the platinum alloy coated with the coating material (plastic coating) in the same manner as in Examples 1 to 4. Moreover, although this coating material (plastic coating) maintained the two-layered structure at 1300 degreeC, it was confirmed that it is changed into a single layer at 1500 degreeC. However, it was confirmed that the protective effect does not disappear even at 1500 degreeC.

(Example 6 and Comparative Examples 2-4)

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

The glass components shown in Table _3, Al ₂ O 3, to prepare a slurry, so that a composition of SiO ₂ and ZrO _2. As the glass component, OA-10 (average particle size 7 µm) was used, Al ₂ O ₃ was used alumina particles (average particle diameter 50 µm), and SiO _{2 was} colloidal silica (colloidal solution of silica: average particle diameter 20 nm). ), And zirconia particles (average particle size 6 µm) were used as ZrO ₂ . It was suspended in 2 times the weight of a solid and methylcellulose was added so that it may become 3 weight% with respect to a solid weight, and the slurry was prepared.

[Application of slurry to platinum crucible]

The slurry was apply | coated to the bottom surface of the outer side of a platinum crucible, and the side surface of the outer side of a platinum crucible (46 mm in diameter, 40 mm in height) by spray coating in the state heated with the hot air gun. The side surface was apply | coated to the position of the height of 25 mm from the bottom surface. After drying at 80 degreeC, a coating material layer was baked by baking a platinum crucible at 1500 degreeC for 5 hours. The thickness of the coating plastic film was 500 micrometers.

[Interface Foaming Test]

After baking of the said coating material, the alumino borosilicate glass (OA-10) was filled in the platinum crucible in the state which lowered the temperature to 1300 degreeC, and it heated up at 1500 degreeC at the temperature increase rate of 10 degree-C / min. It kept at 1500 degreeC for 1 hour.

In a platinum crucible, the thing which hardly foamed is observed was set as (circle), the thing where many foams were seen was evaluated as x, and the interface foaming state was evaluated, and the evaluation result was shown in Table 3.

Moreover, the photograph of the foaming state of the glass in a platinum crucible is shown in FIGS. 4 is Example 6, FIG. 5 is Comparative Example 2, FIG. 6 is Comparative Example 3, and FIG. 7 is Comparative Example 4. FIG.

As is clear from the results shown in Table 3 and FIGS. 4 to 7, Example 6 in which Al ₂ O ₃ and SiO ₂ were included as essential components in the glass component according to the present invention contained only Al ₂ O _{3 in the} glass. Compared with Comparative Example 2, Comparative Example 3 containing only SiO _{2 in the} glass component, and Comparative Example 4 containing SiO ₂ and ZrO ₂ in the glass, it can be seen that foaming can be significantly reduced. From this, it turns out that it is necessary to contain alumina and a silica as an essential component in order to reduce foaming at the time of glass manufacture.

Moreover, the coating material of this Example was able to reduce the volatilization loss of platinum similarly to Examples 1-5.

(Examples 7-9)

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

The slurry solution of the composition of Examples 7-9 shown in Table 4 was prepared. A glass component, roneun Al ₂ O ₃ and SiO _2, the same was used as that used in Example 6.

[Application of Coating Material to Platinum Crucibles]

In the state which heated the inner surface of the sandblasted platinum crucible (46 mm in diameter, 40 mm in height) by the hot air gun, it carried out similarly to Example 6 to the bottom surface and outer side of the outer side of a platinum crucible, The slurry was spray coated. After coating so that the film thickness after baking might be set to 500 micrometers, it dried at 80 degreeC and formed the slurry coating material layer.

The platinum crucible in which the slurry coating material layer was formed as described above was calcined at the test temperature for 5 hours, and then lowered to 200 ° C lower than the test temperature, and then the aluminoborosilicate glass (OA-10) was charged into the platinum crucible. About Examples 7-9, it heated up at the temperature increase rate of 10 degree-C / min to the test temperature shown in Table 4, and hold | maintained at each test temperature for 1 hour after that. Table 4 shows the interfacial foaming state at this time.

As can be seen 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 ₃ and SiO ₂ as an essential component was applied to the glass component, Foaming can be reduced. Moreover, as shown in Table 4, as a use temperature range becomes high, heat resistance which can endure a high use temperature range can be given to a coating material by reducing a glass component and increasing an alumina component.

The coating material of the present Example was able to reduce the volatilization loss of platinum similarly to Examples 1-5.

(Example 10)

This example is an example using the coating material of the paste form which concerns on 2nd Embodiment of this invention.

As shown in Table 5, 37.5% by weight of the glass component (OA-10), 39.0% by weight of alumina (Al ₂ O ₃ ) particles, and 23.5% by weight of silica (SiO ₂ ) particles were used. The sintered compact of the mixture was produced. As the silica particles, those having an average particle diameter of 20 μm were used, and those used in Example 6 were used as the alumina particles. Sintering conditions were 1500 degreeC and it was 24 hours, The obtained sintered compact was grind | pulverized, and it was set as the pulverized material about 20 micrometers in average particle diameter.

The resultant pulverized product 100 parts by weight of alumina fibers (97 wt% Al ₂ O ₃ -3% by weight of SiO _2, an average fiber length 10㎜, average fiber length 3㎛) 5 parts by weight to 9 parts by weight of cellulose resin The mixture paste was added to the aqueous solution dissolved so that it might become%. The ratio of the aqueous solution of methylcellulose resin was 40 parts by weight based on 100 parts by weight of the total of the pulverized product and the alumina fiber.

[Adhesion of Paste to Platinum Crucible]

The said paste was affixed on the bottom surface and the outer side surface of the sandblasting-processed platinum crucible (46 mm in diameter, 40 mm in height) outside. The position at which the paste is applied was set to the same position as in Example 6. After the paste was applied, the product was calcined at 1500 ° C. for 5 hours, and after firing, the temperature was lowered to 1300 ° C., and the alumino borosilicate glass (OA-10) was charged into the platinum crucible at this temperature, and then the temperature increase rate was 10 ° C./min. The temperature was raised to 1500 degreeC by and hold | maintained at 1500 degreeC for 1 hour. The interfacial foaming state at this time was evaluated and shown in Table 5.

As shown in Table 5, also in Example 10 using the coating material of the paste form which concerns on 2nd Embodiment of this invention, it turns out that foaming at the time of glass manufacture can be reduced. In addition, in the paste of this example, cracks did not occur even after firing. Moreover, the volatile loss of platinum was able to be reduced similarly to Examples 1-5.

(Examples 11 to 13)

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

[Preparation of slurry coating material]

As shown in Table 6, a slurry was prepared using OA-10 as the glass component, alumina particles as Al ₂ O ₃ , and colloidal silica as SiO ₂ . In addition, the same thing as Example 6 was used for the alumina particle and colloidal silica. The numerical value in () shown in the column of colloidal silica of Table 6 is a compounding ratio as a solution of colloidal silica. Three types of slurry a1, b1, and c1 were manufactured using the 1.5 weight% aqueous solution of methylcellulose resin as an organic binder in the compounding ratio shown in Table 6.

[Production of paste]

The sintered compacts a2, b2, and c2 are mixed by mixing the glass component (OA-10), Al ₂ O _3, and SiO ₂ in the ratio shown in Table 7, the mixture is sintered at 1500 ° C. for 24 hours, and the resulting sintered compact is pulverized. Prepared.

Next, about the obtained sintered compact, as shown in Table 8, the organic binder and the alumina fiber were mixed, and three types of pastes a3, b3, and c3 were manufactured.

[Application of Coating Material to Platinum Crucibles]

Slurry-type coating material shown in Table 6 on the bottom surface and the outer side of the outer side of the platinum crucible while the inner surface of the sandblasted platinum crucible (46 mm in diameter and 40 mm in height) was heated by a hot air gun. After spray-coating a1, b1, and c1, respectively, it dried at 80 degreeC and formed the slurry coating material layer.

Next, paste a3, b3, and c3 shown in Table 8 were stuck on the slurry coating material layer formed as mentioned above, and then dried, and the protective coating material layer was formed.

Next, the platinum crucible in which the slurry coating layer and the protective coating layer were formed as described above was heated up to the respective test temperatures at a heating rate of 10 ° C./min, and maintained at that temperature for 5 hours to maintain the slurry coating layer and the protective coating layer. Was fired. In addition, the thickness of the slurry coating baking layer of the baking film obtained by each Example was 500 micrometers, and the thickness of the protective coating baking layer was 5 mm.

The aluminoborosilicate glass (OA-10) was filled in the state which lowered the platinum crucibles of Examples 11-13 which formed the coating baking film as mentioned above to the temperature 200 degreeC lower than test temperature, and after that to the test temperature It heated up at the temperature increase rate of 10 degree-C / min, and hold | maintained at each test temperature for 1 hour after that. Table 9 shows the interfacial foaming state at this time.

As is apparent from the results shown in Table 9, it is understood that in Examples 11 to 13 according to the third embodiment of the present invention, foaming at the time of glass production can be reduced.

In addition, the coating material of the present Example was able to reduce the volatilization loss of platinum similarly to Examples 1-5.

<Application example for glass manufacturing equipment>

Next, the Example performed about the manufacturing equipment of the glass to which this invention was applied, and the manufacturing method of the glass for displays by this apparatus is demonstrated. First, the structure of glass manufacturing equipment is demonstrated. It is explanatory drawing which shows the structure of a glass manufacturing equipment.

The glass manufacturing equipment 1 is provided in the substantially rectangular dissolution tank 2 used as a supply source of a molten glass, the clarification tank 3 formed in the downstream side of the dissolution tank 2, and the downstream side of the clarification tank 3, and the like. It has the stirring tank 4 and the shaping | molding apparatus 5 formed in the downstream of the stirring tank 4, The dissolution tank 2, the clarification tank 3, the stirring tank 4, and the shaping | molding apparatus 5 are respectively It is connected by the communication flow paths 6, 7, 8.

The dissolution tank 2 has a bottom wall, side walls and a ceiling wall, each of which is formed of a refractory. A burner, an electrode, etc. are formed in the melting tank 2, and can melt a glass raw material. The outlet side is formed in the side wall of the downstream side of the dissolution tank 2, and the dissolution tank 2 and the clarification tank 3 communicate with each other through the narrow communication flow path 6 which has this outlet at an upstream end.

The clarification tank 3 has a bottom wall, a side wall, and a ceiling wall. The inner wall surfaces (at least the inner wall surface portions in contact with the molten glass) of the bottom wall and the side wall are made of platinum or a platinum alloy, and protective refractory is formed on the outside thereof. As for the clarification tank 3, the downstream end of the outflow path 6 opens to the side wall of an upstream. This clarification tank 3 is a site where clarification of glass is mainly performed, and the microbubble contained in glass expands and floats with the clarification gas discharged from a clarifier, and is removed from glass. The outlet side is formed in the side wall of the downstream side of the clarification tank 3, and the stirring tank 4 communicates with the downstream side of the clarification tank 3 via the narrow communication flow path 7 which has an outlet at an upstream end. .

The stirring vessel 4 has a bottom wall, side walls, and a ceiling wall. The inner wall surfaces (at least the inner wall surface portions in contact with the molten glass) of the bottom wall and the side wall are made of platinum or a platinum alloy, and protective refractory is formed on the outside thereof. The stirring tank 4 is a site | part which stirs and homogenizes a molten glass mainly with a stirrer.

The outlet side is formed in the side wall of the downstream side of the stirring vessel 4, and the shaping | molding apparatus 5 is communicated with the downstream side of the stirring vessel 4 via the narrow communication flow path 8 which has an outlet at an upstream end. .

As the shaping | molding apparatus 5, when it is shaping | molding of display glass, plate glass shaping | molding apparatuses, such as a downdraw shaping | molding apparatus, an updraw shaping | molding apparatus, a float shaping | molding apparatus, are used, for example. In particular, in the case of liquid crystal plate glass, an overflow downdraw apparatus is preferable.

Moreover, the communication flow path 6 which connects the dissolution tank 2 and the clarification tank 3 is formed with the refractory, and the other communication flow path, ie, the clarification tank 3 and the stirring tank 4, which connects The communication flow path 8 which connects the communication flow path 7 and the stirring tank 4 and the shaping | molding apparatus 5 is formed with platinum or a platinum alloy, and the protective refractory is provided in the outer side.

In this example, the coating firing according to the third embodiment of the present invention is performed on the outer surface of the glass manufacturing facility (here, the clarification tank 2 to the contact flow path 8) made of platinum or platinum alloy in the production facility. A coating calcined film having a protective coating calcined layer was formed on the film, that is, the slurry coated calcined layer. As such a coating baking film, the coating material of Examples 11-13 can be used preferably, for example.

And the method of manufacturing glass for a display using the glass manufacturing equipment which has the above structures is as follows.

First, glass raw materials are combined. For example, specifically, in terms of mass percentage, so as to be a glass having a composition of SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -RO (RO is one or more of MgO, CaO, BaO, SrO, and ZnO). SiO ₂ 50-70%, Al ₂ O ₃ 10-25%, B ₂ O ₃ 5-20%, MgO 0-10%, CaO 3-15%, BaO 0-10%, SrO 0-10%, ZnO 0~10%, TiO ₂ 0~5%, and a combination of a glass raw material so that the alkali-free glass containing 0~5% P ₂ O _5. Moreover, in addition to the above, various components, such as a clarifier, can be added.

Next, the combined glass raw material is thrown into the dissolution tank 2, and it melts and vitrifies. In the melting tank 2, glass is heated from above by the combustion salt of a burner. In the case of the SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -RO glass, the glass is melted at about 1500 to 1650 ° C.

The molten glass vitrified in the dissolution tank 2 is guided to the clarification tank 3 via the communication flow path 6. The molten glass contains initial bubbles generated during the vitrification reaction, but in the clarification tank 3, the initial bubbles are expanded and removed by the clarification gas released from the clarifier component.

The molten glass clarified in the clarification tank 3 is guide | induced to the stirring tank via the communication flow path 7. In the stirring vessel 4, glass is stirred and homogenized by the rotating stirrer.

The molten glass homogenized in the stirring tank 4 is guided to the shaping | molding apparatus 5 through the communication flow path 8, and is shape | molded in plate shape. In this way, the glass for a display can be obtained.

Generally, the communication flow path 6 from the dissolution tank 2 to the clarification tank 3 is corresponded to the use temperature range of 1450 degreeC-1600 degreeC, and it is the stirring tank 4 in the clarification tank 3 and the clarification tank 3. The contact flow path 7 to the furnace and the stirring tank 4 correspond to a use temperature range of 1250 ° C to 1450 ° C, and the communication flow path 8 from the stirring tank 4 to the molding apparatus 5 is 1000 ° C to 1250 ° C. Corresponds to the temperature range of use.

In the glass manufacturing apparatus of the present Example, the volatilization loss of platinum from the manufacturing apparatus was suppressed even after the long-term operation of the apparatus at the time of performing the manufacturing method of said glass. As a result, the strength and stability of the manufacturing apparatus were maintained for a long time. Moreover, generation | occurrence | production of the bubble at the time of glass manufacture was able to be reduced. In addition, the apparatus which concerns on a present Example is naturally applicable also to manufacture of glass other than glass for a display.

Claims (34)

A material for coating the surface of a platinum material consisting of platinum or platinum alloy, A refractory material component containing alumina and silica and a coating material for platinum material containing a glass component. The method of claim 1, The coating material for platinum materials whose glass components are borosilicate glass and alumino borosilicate glass which do not contain an alkali. The method according to claim 1 or 2, The coating material for platinum materials whose content of alumina, a silica, and a glass component is 15 to 55 weight% of alumina, 10 to 50 weight% of silica, and 20 to 70 weight% of a glass component. The method according to any one of claims 1 to 3, A coating material for platinum material, wherein at least part of the silica is colloidal silica. The method of claim 4, wherein Alumina particle, a glass component, and colloidal silica are contained, The coating material for platinum materials. The method of claim 4, wherein A pulverized product obtained by pulverizing a sintered compact of a mixture of alumina particles and a glass component, and colloidal silica, the coating material for a platinum material. The method according to any one of claims 1 to 3, A coating material for platinum materials, comprising a slurry containing alumina particles, a glass component, and silica particles. The method of claim 5, A coating material for platinum materials, comprising a slurry containing alumina particles, a glass component, and colloidal silica. The method of claim 6, A coating material for platinum materials, comprising a pulverized product obtained by pulverizing a sintered compact of a mixture of alumina particles and a glass component and a slurry containing colloidal silica. The method according to any one of claims 7 to 9, A coating material for platinum materials, wherein the slurry contains an organic binder. The method according to any one of claims 1 to 3, A coating material for platinum materials, comprising a pulverized product obtained by grinding a sintered compact of alumina particles, a mixture of silica particles, and a glass component. The method according to any one of claims 1 to 3, A coating material for platinum materials, comprising a paste or green sheet containing alumina particles, silica particles, and a glass component. The method of claim 11, A coating material for platinum materials, comprising a paste or green sheet containing a pulverized product obtained by pulverizing a sintered compact of alumina particles, a mixture of silica particles, and a glass component. The method according to claim 12 or 13, At least a part of the alumina particles are fibrous alumina particles, wherein the coating material for platinum material. The method according to any one of claims 12 to 14, A coating material for platinum materials, wherein the paste or green sheet contains an organic binder. The coating material of any one of Claims 1-15 is apply | coated or affixed on the surface of a platinum material, and then baked, The coating method of the platinum material characterized by the above-mentioned. The method of claim 16, The coating method of the platinum material characterized by baking after apply | coating the slurry in any one of Claims 7-10 to the surface of a platinum material. The method of claim 17, A method of coating a platinum material, wherein the slurry is applied to the surface of the platinum material by spraying. The paste or green sheet as described in any one of Claims 12-15 is affixed on the surface of a platinum material, and it bakes, The coating method of the platinum material characterized by the above-mentioned. The method of claim 16, The slurry as described in any one of Claims 7-10 is apply | coated to the surface of a platinum material, and a slurry coating layer is formed, On this slurry coating layer, the paste or green as described in any one of Claims 12-15. A method of coating a platinum material, which is fired after pasting a sheet to form a protective coating layer. The method according to any one of claims 16 to 20, A method of coating a platinum material, which comprises applying or applying a coating material after blasting the surface of the platinum material. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, It is obtained by baking, after apply | coating or sticking the coating material in any one of Claims 1-3, 7, and 11 to the surface of a platinum material, The coating plastic film of the platinum material characterized by the above-mentioned. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, A coated plastic film of platinum material, wherein alumina particles and silica particles are dispersed as a dispersed phase on a matrix composed of a glass component. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, It is obtained by baking after apply | coating the coating material in any one of Claims 4-6 and 8-10 to the surface of a platinum material, The coating plastic film of the platinum material characterized by the above-mentioned. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, An alumina particle is dispersed as a dispersed phase on the matrix which consists of a glass component and a colloidal silica component, The coating plastic film of the platinum material characterized by the above-mentioned. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, It is obtained by sticking the paste or green sheet in any one of Claims 12-15 to the surface of a platinum material, and baking it, The coating baking film of the platinum material characterized by the above-mentioned. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, The slurry as described in any one of Claims 7-10 is apply | coated to the surface of a platinum material, and a slurry coating layer is formed, On this slurry coating layer, the paste or green as described in any one of Claims 12-15. It is obtained by baking, after pasting a sheet | seat and forming a protective coating layer, The coating baking film of the platinum material characterized by the above-mentioned. The method of claim 27, In the slurry coating layer, alumina particles are dispersed as a dispersed phase on a matrix composed of a glass component and a colloidal silica component. The method of claim 27 or 28, In the protective coating layer, alumina particles and silica particles are dispersed as a dispersed phase on a matrix made of a glass component, wherein the coated plastic coating film of platinum material. As a plastic film which coats the surface of the platinum material which consists of platinum or a platinum alloy, A coating calcined coating film of platinum material obtained by firing a coating material having a two-layer structure consisting of a first coating layer made of a mixture of alumina and silica and in contact with a platinum material and a second coating layer made of a glass component on the coating layer. . The platinum material which consists of platinum or a platinum alloy which coat | covered the coating material in any one of Claims 1-15. 30. A platinum material made of platinum or a platinum alloy, wherein the coated plastic coating of Claims 22 to 29 is formed on the surface. As a glass manufacturing apparatus which uses the platinum material which consists of platinum or a platinum alloy as a component material, The coating material of any one of Claims 1-15 was coat | covered at the outer surface, The glass manufacturing apparatus characterized by the above-mentioned. As a glass manufacturing apparatus which uses the platinum material which consists of platinum or a platinum alloy as a component material, 30. The glass manufacturing apparatus characterized by the above-mentioned coating plastic film formed on the outer surface.

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