JP2000086361A - Heat resistant material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-resistant material having not only dust-preventing properties but also thermal shock resistance and durability, and further to provide a production method thereof. SOLUTION: This heat-resistant material is obtained by forming a glass layer 3 consisting essentially of a glass material 5 so as to be kept in contact with a substrate 2 consisting essentially of an inorganic fiber-based material 4. The substrate 2 includes a glass material 5 as a binder, and the glass layer 3 includes an inorganic fiber-based material 4 as a reinforcing material. The glass material 5 in the substrate 2 is fused with the glass material 5 in the glass layer 3 in the process for carrying out the heating treatment to form the glass layer 3. Continuity and integrity in physical properties are imparted during the heat treatment. The heat-resistant material can have dusting from the surface of the substrate suppressed by the glass layer 3, relieved situation of the stress concentrated on a heterogeneous part of physical properties of the glass layer 3, suppressed crack formed in the glass layer 3, suppressed generation of the peeling phenomenon from the substrate 2, thermal shock resistance and durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant material and a method for producing the same, and more particularly, to a method in which a glass material is contained as a binder in a base material mainly composed of an inorganic fibrous material, and the glass material is used as a main component. The present invention relates to a heat-resistant material in which an inorganic fibrous material is included as a reinforcing material in a glass layer to be provided so that integrity is provided between a substrate and a glass layer, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional heat-resistant material is mainly composed of a heat-resistant inorganic fibrous material such as silica fiber or alumina fiber. And the like. These heat-resistant materials having a predetermined shape are superior to heat-resistant bricks and castables in the following points. It has low heat capacity, low thermal conductivity, resistance to thermal shock, light weight, and low coefficient of thermal expansion.

On the other hand, in recent years, liquid crystal displays and plasma displays using a glass substrate have been frequently used, and since semiconductor elements and wirings are directly formed on the glass substrate, the surface of the glass substrate is required to have an extremely strict cleanness. You. The glass substrate needs to be fired, and is subjected to various heat treatments in advance to remove shrinkage and distortion. Heating furnace is used for firing and various heat treatments for this glass substrate,
As a matter of course, extremely severe conditions are imposed on dust generation from the heat-resistant material constituting the inner wall and the shelf of the heating furnace. This is because if the dust scattered from the heat-resistant material constituting the inner wall of the heating furnace or the shelf during the baking or various heat treatments adheres to the glass substrate surface where the extremely strict cleanness is imposed, the liquid crystal display and the This is because this is a major factor in the generation of defects at the stage of manufacturing a plasma display.

[0004] The above-mentioned heat-resistant material exclusively composed of the inorganic fibrous material is suitable for a heating furnace for baking a glass substrate and performing various heat treatments because of the above-mentioned advantages. Have difficulty. In order to prevent dust generation by covering the surface of a heat-resistant material exclusively composed of an inorganic fibrous material with a glass layer, Japanese Patent Publication No. 57-13514
And Japanese Patent Application Laid-Open No. 1-219038.

The heat-resistant material comprises two or more types of refractory inorganic fibrous materials having a high melting point and a low melting point.
0.5 to 5% by weight of an organic fibrous material, 4 to 20% by weight of a binder, 50 to 90% by weight of a refractory substance and 0.5% by weight or more of a molded article having a refractory and corrosion resistant substance, An antioxidant coating layer containing fine powder, water glass and glass fiber, that is, a glass layer is formed. Therefore, by the antioxidant coating layer corresponding to the glass layer,
It is possible to prevent dust generation due to two or more kinds of fire-resistant inorganic fibrous materials. The heat-resistant material is formed by applying a glaze to at least a part of the surface of a porous sintered body composed of a heat-resistant inorganic fibrous material, a refractory powder, and an inorganic binder, and performing a heat treatment to form a glass layer. It becomes. Therefore, the glass layer can prevent dust generation due to the heat-resistant inorganic fibrous material and the refractory powder.

[0006]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Publication No. Sho 57-1
The known examples disclosed in Japanese Patent No. 3514 and Japanese Patent Application Laid-Open No. 1-219038 are convenient in that point because dust is prevented from being generated from the surface of a heat-resistant material exclusively formed of an inorganic fibrous material by a glass layer. However, these heat-resistant materials have low thermal shock resistance and durability, so that rapid heating and long-term use cannot be performed. If rapid heating is performed, cracks occur in the glass layer, and a phenomenon of peeling from the base material occurs. In addition, if the glass layer is used for a long period of time, the glass layer is also cracked, and a peeling phenomenon occurs. In other words, since the firing and various heat treatments for the glass substrate are constantly performed in the heating furnace, the heat-resistant material used for the inner wall and the shelf of the heating furnace is required to have not only the dustproof property but also the thermal shock resistance and the durability. It is.

Accordingly, an object of the present invention is to provide a heat-resistant material having both thermal shock resistance and durability as well as dust-free properties, and a method for producing the same.

[0008]

Under these circumstances, the present inventors have conducted intensive studies, and as a result, have found that a base material mainly composed of an inorganic fibrous material and a glass layer mainly composed of a glass material have a high thermal conductivity. Different expansion coefficients cause stress between the substrate and the glass layer, while the physical properties of the glass layer are uneven in thickness, uneven in density, uneven in hardness, and composition. There is a non-uniformity such as non-uniformity, and the above stress concentrates on the non-uniform part of the physical properties of the glass layer, which leads to cracks in the glass layer and a phenomenon of peeling from the base material. did. If the inorganic fibrous material, which is the main component of the base material, is used as a reinforcing material for the glass layer, and the glass material, which is the main component of the glass layer, is used as a binder for the base material, the heat treatment for forming the glass layer can be performed. In the process, the glass material serving as a binder in the base material and the glass material of the glass layer are fused to provide physical continuity and integrity between the base material and the glass layer. It has been found that the situation in which stress is concentrated on a portion of the glass layer having non-uniform physical properties is alleviated, cracks are generated in the glass layer, and peeling off from the base material is suppressed, and the present invention has been found. It was completed.

That is, according to the present invention, a glass layer mainly composed of a glass material is provided in contact with a substrate mainly composed of an inorganic fibrous material, and the substrate contains the glass material as a binder. The glass layer provides a heat-resistant material comprising the inorganic fibrous material as a reinforcing material.

In the present invention, as shown in FIG. 1, the heat-resistant material 1 is composed of a glass layer 3 which is a dense material covering a base material 2 which is a porous material. A certain inorganic fibrous material 4 is included in the glass layer 3 to function as a reinforcing material.
To function as a binder by including
The glass layer 3 is formed by heat treatment.
That is, at the interface 6 between the base material 2 and the glass layer 3, the glass material 5 in the base material 2 and the glass material 5 in the glass layer 3 are fused, although not shown in the figure, and the base material 2 and the glass layer 3 are fused. Physical continuity and integrity are imparted to the glass layer 3, and the situation where stress is concentrated on a portion of the glass layer 3 where the physical properties are not uniform as described above is alleviated.

The inorganic fibrous material 4 is not particularly limited, and examples thereof include silica-alumina-based ceramic fibers. Specifically, Al ₂ O ₃ is 40 to 6
0 wt%, amorphous silica-alumina based ceramics SiO ₂ consists of 40 to 60 wt%, Al ₂ O ₃ is from 70 to 9
A crystalline silica-alumina-based ceramic comprising 9% by weight and 1 to 30% by weight of SiO ₂ is used. Preferably, the average fiber length is 50 to 150 μm and the average fiber diameter is 1 to 5 μm. These inorganic fibrous materials may be used alone or as a mixture. The composition ratio between Al ₂ O ₃ and SiO ₂ can be appropriately selected depending on the application.

The glass material 5 is not particularly limited, and examples thereof include borosilicate glass, potash glass, lead potash glass, quartz glass, and aluminosilicate glass.
These glass materials may be used alone or in combination. Further, among glass materials, borosilicate glass is particularly preferable. Therefore, as the heat-resistant material of the present invention, it is preferable that the inorganic fibrous material 4 uses silica-alumina-based ceramic fiber, and the glass material 5 uses borosilicate glass. The compatibility between the silica component and the glass component of the borosilicate glass is good, and the occurrence of cracks in the glass layer 3 and the peeling of the glass layer 3 from the substrate 2 can be suppressed extremely well.

The content of the inorganic fibrous material 4 in the glass layer 3 is preferably in the range of 5 to 15% by weight,
More preferably, it is in the range of 5% by weight. If the amount of the inorganic fibrous material 4 is less than 5% by weight, the effect of suppressing the generation of cracks in the glass layer 3 cannot be expected. On the other hand, when the amount of the inorganic fibrous material 4 exceeds 15% by weight, the inorganic fibrous materials 4 are entangled with each other to form a portion having non-uniform physical properties in the glass layer 3, so-called fiber lump is generated. This is not preferable because it causes cracks and peeling in No. 3.

The content of the glass material 5 in the substrate 2 is preferably in the range of 10 to 30% by weight. If the glass material is less than 10% by weight, the portion of the glass layer 3 that is fused to the glass material is reduced, and physical continuity and integrity cannot be maintained. Conversely, if the glass material 5 exceeds 30% by weight, superior properties as a heat-resistant material cannot be exhibited.

In the present invention, the inorganic fibrous material which is the main component of the substrate and the inorganic fibrous material which is the reinforcing material of the glass layer may be the same or different. It is preferable to use the same material. Further, the glass material of the glass layer and the glass material as the binder of the base material may be the same material or different materials, but it is preferable to use the same material from the viewpoint of fusion strength. .

Next, a method for manufacturing the heat-resistant material of the present invention will be described. That is, the method for producing a heat-resistant material of the present invention comprises a step of mixing a glass material, an organic binder, an inorganic fibrous material, and water to produce a paste-like or paste-like starting material; And a step of applying the starting material to at least a part of the surface of the substrate using the glass material as a binder, and a step of transforming the glass material into a glass layer by a heat treatment.

First, the base material 2 is prepared in advance by binding the inorganic fibrous material 4 using the glass material 5 as an inorganic binder, forming and processing into a predetermined shape, drying, and further firing before the coating step. You. For example, 100 parts by weight of a silica-alumina-based inorganic fiber material, 10 to 30 parts by weight of boric acid, 10 to 30 parts by weight of colloidal silica, 0.3 to 1 part by weight of alumina sol, and 0.5 to 1.5 parts by weight of an organic binder are mixed. Then, a slurry having a concentration of 3 to 4% by weight is obtained. Next, this slurry is subjected to dehydration molding,
Drying is performed for 時間 8 hours, and then firing is performed at 1000 to 1200 ° C. for several hours to tens of hours. Thereby, a base material mainly composed of a silica-alumina-based inorganic fibrous material can be obtained.

In the step of preparing the starting material, an organic binder is used. Examples of the organic binder include polyethylene oxide, polyvinyl alcohol, methyl cellulose, and the like, and these may be used alone or in combination. In addition, the mixing amount of the organic binder is as follows.
Preferably, the amount is 1 to 5 parts by weight based on 00 parts by weight. When mixing each of the above-mentioned raw materials, it is important to adjust the starting material to include the inorganic fibrous material 4 in the range of 5 to 15% by weight. 4 to make it possible. That is, when the organic binder is not used, the starting material becomes a slurry, the dispersibility of the inorganic fibrous material 4 is poor, and the starting material can be contained only up to about 3% by weight. For example, even if it exceeds 3% by weight, the inorganic fibrous material 4 is unevenly distributed, and the effect of suppressing the generation of cracks in the glass layer 3 cannot be expected. When borosilicate glass is used for the glass material 5 among these organic binders, it is preferable to use polyethylene oxide in that good results can be obtained with good reproducibility.

Examples of mixing in the process of preparing the starting materials include 20 to 30 parts by weight of borosilicate glass powder, 0.2 to 0.4 parts by weight of an organic binder, and 1 to 4.5 parts by weight of a silica-alumina-based inorganic fibrous material. And 20 to 40 parts by weight of water.

Next, the starting material is applied to the surface of the substrate 2 in an application step. As described above, since the starting material uses an organic binder, it has good elongation and can be uniformly applied to the surface of the base material 2 with a brush or the like, and further contains an inorganic fibrous material 4 which is a porous material as a main component. To the inside of the base material 2 can be appropriately suppressed, and a coating film having a smooth surface can be formed. The application to the substrate may be performed on all surfaces of the substrate, or may be performed on a part thereof. After the substrate on which the coating film has been formed, a glass layer is formed in a denaturation step in which heat treatment is performed after drying.

When the substrate 2 on which the coating film of the starting material is formed in the metamorphosis step is subjected to a heat treatment, the coating film becomes the glass layer 3. At this time, the glass layer 3 is made of the glass material 5 in the starting material.
Is melted and the inorganic fibrous material 4 contained in the starting material 4
Is used as a reinforcing material. At the same time, the glass material 5 is used as an inorganic binder in the process of preparing the base material 2 in advance.
Therefore, the glass material 5 in the starting material forming the glass layer 3 and the glass material 5 in the base material 2 are melted and fused. The heat treatment is performed at a heating temperature of 1000 to 1200 ° C.
What is necessary is just to perform on the conditions of 20 to 60 minutes of heating time. The thickness of the glass layer is not particularly limited.
The thickness is about 200 μm. Note that the organic binder and water in the starting materials are diffused by the heat treatment.

The heat-resistant material 1 thus produced is
At the interface 6 between the base material 2 and the glass layer 3, both glass materials 5
In a state where they are fused to each other, physical continuity and integrity are provided between the substrate 2 and the glass layer 3, and the inorganic fiber as a reinforcing material is also provided in the glass layer 3. Quality material 4. Therefore, the situation in which the stress is concentrated on the portion of the glass layer 3 where the physical properties are uneven is alleviated.
Cracks do not occur in the glass layer 3 and the glass layer 3 does not peel off from the substrate 2.

[0023]

Next, the present invention will be described in more detail with reference to examples, but this is merely an example and does not limit the present invention. Reference Example 1 (Preparation of Base Material) First, a base material was prepared with the following raw materials and mixing ratios. Silica-alumina ceramic fiber (51% by weight of silica component, 49% by weight of alumina component, average fiber length 50μm, average fiber diameter 2.5μm) 100 parts by weight Boric acid 4 parts by weight Colloidal silica 25 parts by weight Alumina sol 0.6 parts by weight 0.8 parts by weight of a polyacrylamide-based binder The raw materials having the above composition were mixed to form a slurry having a concentration of 3.5% by weight, and a square tile shape was formed by a dehydration molding method. This was dried at 125 ° C. for 5 hours, and further baked at 1100 ° C. for 10 hours to obtain a substrate having a size of 200 mm × 25 mm. By the above calcination, boric acid, colloidal silica, and alumina sol react to generate borosilicate glass, and the borosilicate glass becomes an inorganic binder, and the silica-alumina-based ceramic fibers bond with each other to form a base material.

Example 1 A starting material prepared as described below was applied to the substrate obtained in Reference Example 1 and fired to form a glass layer to obtain a heat-resistant material. First, 20 g of borosilicate glass powder and 0.25 g of polyethylene oxide were mixed, and 18 g of water was further added and stirred. 2.0 g of silica-alumina-based ceramic fiber and 10 g of water were added and stirred, and the starting material, that is, A starting material containing 9% by weight of silica-alumina-based ceramic fibers was obtained. Next, this starting material was applied only to the surface of the base material of Reference Example 1 by brush coating so that the application amount was 9.3 g (borosilicate glass powder) / 100 cm ² . After drying, the coated substrate was baked at 1150 ° C. for 60 minutes to obtain a heat-resistant material. The thickness of the glass layer after firing was in the range of 100 to 200 μm. A spalling test was performed on the obtained heat-resistant material. Table 1 shows the results.

(Spalling test) This is a rapid heat quenching test. First, a test material is immediately put into a test furnace kept at 500 ° C. from a state of normal temperature (20 ° C.). Then, after holding this test material in an atmosphere of 500 ° C. for 30 minutes,
Remove from the test furnace and cool naturally for 30 minutes. This is performed as one cycle for 5 cycles, and the result is visually observed. The temperature of the rapid heat quenching test was set to 600 ° C, 700 ° C,
The temperature is raised in units of 800 ° C., 900 ° C. and 100 ° C. until the occurrence of cracks, peeling, and other obstacles occurs.

Example 2 A heat-resistant material was obtained in the same manner as in Example 1, except that the starting material contained 5% by weight of silica-alumina-based ceramic fibers. The same rapid heat quenching test as in Example 1 was performed on this heat resistant material.

Example 3 A heat-resistant material was obtained in the same manner as in Example 1, except that the starting material contained 7% by weight of a silica-alumina-based ceramic fiber. The same rapid heat quenching test as in Example 1 was performed on this heat resistant material.

Example 4 A heat-resistant material was obtained in the same manner as in Example 1 except that the starting material contained 14% by weight of silica-alumina-based ceramic fibers. The same rapid heat quenching test as in Example 1 was performed on this heat resistant material.

Comparative Example 1 The same starting material as in Example 1 was used except that the starting material did not contain any silica-alumina-based ceramic fibers. This starting material was applied only to the surface of the substrate of Example 1,
9.3 g (borosilicate glass powder) / 100 cm ²
Was applied by brush coating so that Then, the coated base material was dried and baked at 1150 ° C. for 60 minutes to obtain a heat-resistant material. A spalling test was performed on the obtained heat-resistant material. Table 1 shows the spalling test results of Examples 2 to 4 and Comparative Example 1.

[0030]

[Table 1]

According to Table 1, in Example 1, there was no change up to 800 ° C., and at 900 ° C., the interlayer of the base material was broken, but the glass layer did not change. Example 2 and Example 3
In the first cycle at 600 ° C., cracks occurred in the glass layer. Example 4 shows no change up to 800 ° C.
At ℃, the interlayer of the base material was broken, but the glass layer did not change. On the other hand, in Comparative Example 1, cracks occurred in the glass layer at the first cycle of 500 ° C., and a clear difference was observed between Examples 1 to 4.

[0032]

According to the present invention, by forming a glass layer on the surface of a substrate, dust generation from the surface of the substrate can be suppressed. The glass layer uses an inorganic fibrous material, which is the main component of the substrate, as a reinforcing material, and the glass material, which is a main component of the glass layer, as a binder of the substrate. In the process, the glass material in the base material and the glass material in the glass layer are fused, giving physical continuity and integrity between them, and the stress is uneven in the physical properties of the glass layer. Such a situation can be alleviated, and the occurrence of cracks in the glass layer and the phenomenon of peeling from the base material can be suppressed, and both heat shock resistance and durability can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a heat-resistant material according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat resistant material 2 Base material 3 Glass layer 4 Inorganic fiber material 5 Glass material 6 Interface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuhiro Torii 1-8-1 Shintoda, Hamamatsu-shi, Shizuoka Nichias Inside Hamamatsu Laboratory Co., Ltd. (72) Inventor Yuta Watanabe 1-8-1, Shintoda, Hamamatsu-shi, Shizuoka Nichias Hamamatsu Research Laboratory Co., Ltd. (72) Inventor Tetsuya Mihara 1-1-26 Shiba Daimon, Minato-ku, Tokyo Nichias Corporation

Claims (6)

[Claims] 1. A base material containing an inorganic fibrous material as a main component,
A heat-resistant material comprising a glass layer containing a glass material as a main component, wherein the base material contains the glass material as a binder, and the glass layer contains the inorganic fibrous material as a reinforcing material. . 2. The heat-resistant material according to claim 1, wherein the content of the inorganic fibrous material contained in the glass layer is 5 to 15% by weight. 3. The heat-resistant material according to claim 1, wherein the inorganic fibrous material is a silica-alumina-based ceramic fiber, and the glass material is borosilicate glass. 4. The glass material in the base material and the glass material in the glass layer are fused at an interface between the base material and the glass layer. Heat resistant material. 5. A step of mixing a glass material, an organic binder, an inorganic fibrous material, and water to produce a paste-like or paste-like starting material;
A step of applying the starting material to at least a part of the surface of the base material using the glass material as a binder, and a step of transforming the glass material into a glass layer by a heat treatment; Production method. 6. The method according to claim 5, wherein the organic binder is polyethylene oxide.