JP6598961B1 - Inorganic fiber molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process with high strength, excellent wear resistance, excellent heat spalling property, easy to handle, almost no foreign matter, voids, cracks, etc. Provided is an inorganic fiber molded body having excellent properties. Preferably, the content of ceramic fiber consisting of at least one of silica fiber, alumina fiber, silica-alumina fiber and biosoluble fiber is 10 to 60% by mass, and the content of colloidal silica is converted to solid content. 1.0 to 10% by mass, the boron compound content is 1.0 to 10% by mass in terms of boron oxide, and the remainder is at least MgO-containing ceramic powder (excluding boron compounds). [Selection figure] None

Description

The present invention is durable lightweight and high strength, thermal expansion coefficient superior to small heat spalling resistance, surface roughness is small, about the inorganic fibrous molded body excellent in workability.

  As a heat insulating material having a low density and excellent strength, a technique has been proposed in which ceramic fibers are fused with a boron compound to form a three-dimensional structure. For example, Patent Document 1 discloses a fiber porous refractory in a form in which a contact portion of a porous molded article made of one or both of alumina silica fiber and silica fiber is fused with boron-containing glass, It is described that it can be used for a heat insulating material for high temperature heat resistance, a filter for high temperature fluid, a catalyst carrier, metal reinforcement and the like.

  In addition, Patent Document 2 and Patent Document 3 include silica fibers and alumina having a predetermined average fiber diameter as a heat insulating material having excellent heat resistance and thermal shock resistance in addition to excellent low density and strength. A heat insulating structure having a three-dimensional network structure in which ceramic fibers such as fibers are fused with boron oxide is disclosed. The heat insulating structure is a heat insulating material for surface protection of a reusable spacecraft such as a US NASA space shuttle. It can be used as

Further, Patent Document 4 discloses a heat insulating material made of a porous molded body in which alumina silicate fibers are bonded or fused together with an inorganic binder such as alumina sol or silica sol as a bending mold for a bending mirror. As examples of this porous molded body, those having a bulk density of 0.60 g / cm ³ and 0.40 g / cm ³ are shown, both of which have better durability than conventionally used diatomaceous earth. It is stated that there is.

Japanese Patent Publication No.2-12896 Japanese Patent Publication No. 4-28666 Japanese Patent No. 2819351 Japanese Patent Application No. 62-283818

However, since the fiber porous refractory of Patent Document 1 has a low bulk density of 0.18 to 0.21 g / cm ³ , it can be used as a general heat insulating material. It is insufficient for use in glass rolls such as disk rolls, high-performance ceramics setters that are excellent in air permeability and smoothness, and automotive door mirrors.

Insulation Patent Documents 2 and 3 also, the range of bulk density respectively low as 0.10 to 0.40 g / cm ³ and 0.08~0.30g / cm ^3, as the application other than insulation, strength It was insufficient. Moreover, it is thought that it is difficult to employ | adopt the porous molded object of patent document 4 as a glass mold | die at the time of bending the glass for curved mirrors, such as a door mirror and a room mirror currently produced recently. The reason for this is that recent dies are required to have higher density, higher strength, and superior durability, and are also required to have low thermal expansion and excellent heat-resistant spalling properties. .

  The present invention has been made in view of the problems of the above-described conventional heat insulating materials, and is a setter excellent in air permeability and smoothness used for disk rolls for producing plate glass, firing of high performance ceramics, and the like. It can be used for various heat insulation applications such as glass bending dies for automobile door mirrors, etc., and has high strength, more wear resistance, and low thermal expansion coefficient due to its low thermal expansion coefficient. Inorganic fiber with excellent poling property, good handling and workability, almost no foreign matter, voids and cracks, almost no change in shape even after repeated use at high temperature, and excellent workability The object is to provide a molded body.

In order to achieve the above object, the inorganic fiber molded body provided by the present invention has a ceramic fiber content of 10 to 60 mass%, a colloidal silica content of 1.0 to 10 mass% in terms of solid content, boron. the content of the compound is 1.0 to 10% by weight of boron oxide in terms the balance Ri ceramic powder (excluding boron compound) der containing at least MgO, (excluding boron compound) the ceramic powder is cordierite Of the powder, kaolin powder, and spinel powder, at least cordierite powder is included .

According to the present invention, high strength, excellent wear resistance, excellent heat spalling properties, easy handling, almost no foreign matter, voids, cracks, etc., and almost no change in shape, etc. even when used repeatedly at high temperatures In addition, it is possible to provide an inorganic fibrous shaped article excellent in processability.
It becomes difficult.

  Hereinafter, the inorganic fibrous molded body of the embodiment of the present invention will be described. The inorganic fibrous molded body of this embodiment of the present invention has a ceramic fiber content of 10 to 60 mass%, preferably 20 to 50 mass%, more preferably 30 to 40 mass%, and a colloidal silica content. Is 1.0 to 10% by mass in terms of solid content, preferably 2.0 to 7.0% by mass, and the boron compound content is 1.0 to 10% by mass in terms of boron oxide, preferably 2.0. It is ˜7.0% by mass, and the balance is ceramic powder containing at least MgO. In the present specification, “A to B” means A or more and B or less.

The inorganic fibrous molded body according to the embodiment of the present invention has a bulk density of 500 to 1200 kg / m ³ and is excellent in workability. That is, the quality of workability mainly depends on the bulk density, and if the bulk density exceeds 1800 kg / m ³ , the processing becomes difficult. In addition, the bending strength is 6 MPa or more, the hot linear expansion coefficient is 4.6 × 10 ⁻⁶ / K or less, and in the heat-resistant spalling test at 1000 ° C., cracking occurs even when heating and cooling are repeated for the fifth time or more. The surface roughness (Ra) is 12 μm or less, and the heat shrinkage after holding at 1000 ° C. for 24 hours is 0.3% or less. Furthermore, chemical components, SiO ₂ is 60.0 wt% or more 30.0 wt%, _Al 2 _{O 3} is 50.0 wt% 20.0 wt%, MgO 3.0 wt% or more 13. 0 wt% or less, and _B 2 _{O 3} is 14.0 wt% to 1.4 wt%.

  In this specification, the bulk density is measured according to JIS R2614, the chemical component is measured according to JIS R2216, and the bending strength is measured according to JIS R2619. The hot linear expansion coefficient is measured in accordance with JIS R2207-3, the surface roughness (Ra) is measured in accordance with JIS B0633, and the heating linear shrinkage rate is in accordance with JIS R2613. The heat resistance spalling test was conducted according to JIS R2657.

  The ceramic fiber is one of the substances forming the skeleton of the inorganic fiber molded body of the embodiment of the present invention, and is at least one of silica fiber, alumina fiber, silica alumina fiber, and biosoluble fiber. Preferably there is. These ceramic fibers preferably have an average fiber diameter in the range of 1 to 12 μm, more preferably in the range of 1.5 to 8 μm, and most preferably in the range of 2 to 4 μm. This average fiber diameter was measured based on the “Method for Measuring Fiber Diameter of Ceramic Fiber” by the Japan High Temperature Insulation Wool Industry Association.

The silica fibers are fibers containing high-purity SiO ₂ (95% by mass or more), and the alumina fibers are crystalline alumina fibers and mullite fibers (these are called PCW and AF), and silica-alumina fibers Is a refractory ceramic fiber (also referred to as RCF) amorphous fiber mainly composed of alumina (Al ₂ O ₃ ) and silica (SiO ₂ ). The biosoluble fiber is also called an alkaline earth silicate (AES) fiber, and is an amorphous fiber mainly composed of high-purity silicon dioxide, calcium oxide, or magnesium oxide.

  All of the above fibers are blown by blowing the melted raw material with high-speed air or water vapor to form a fiber, the spinning method of spinning the melted raw material against a rotor that rotates at high speed, and spinning the melted raw material with a nozzle. A spray method that fiberizes by blowing from, a direct melt method that stretches and melts the melted raw material from the nozzle, and a melted raw material is once molded into marbled balls called marbles, which are then remelted and nozzles It can be produced by a marble melt method or the like that is drawn and fiberized.

  When the content of the ceramic fiber exceeds 60% by mass, the density of the formed body becomes too small, and as a result, strength and wear resistance are lowered. On the other hand, if it is less than 10% by mass, the reinforcing effect by the ceramic fibers becomes too small, and the molded body itself is cracked or formed into a molded body with low strength in the demolding after molding.

  The ceramic powder containing at least MgO (excluding the boron compound) is another substance that forms the skeleton of the inorganic fibrous molded body of the embodiment of the present invention, and examples thereof include cordierite powder. In addition to the cordierite powder, the ceramic powder may include kaolin powder, spinel powder, or both. The cordierite powder preferably has a median diameter (D50) of 1 to 40 μm, and more preferably 5 to 25 μm. Also in kaolin and spinel, the median diameter (D50) is preferably 1 to 40 μm, and more preferably 5 to 25 μm. In the present invention, the median diameter (D50) is measured in accordance with JIS Z8825.

  The inorganic fiber molded body preferably has a ceramic powder content of 40 to 85 mass%, more preferably 50 to 70 mass%. If the content is less than 40% by mass, the bulk density may be too small. Conversely, if the content exceeds 85% by mass, the bulk density may be too large. In any case, the quality described in the claims cannot be achieved.

  The colloidal silica is a substance that plays the role of an inorganic binder, and generally has a median diameter (D50) of 5 to 60 nm. When the content of the colloidal silica in terms of solid content is less than 0.1% by mass, the effect as the inorganic binder cannot be obtained. On the contrary, if this content exceeds 10% by mass, molding may be difficult.

  The boron compound is a ceramic having a powder form and plays a role of fusing ceramic fibers together by vitrification, and has an effect of suppressing cristobalite formation. The boron compound is preferably at least one of boron oxide, boron nitride, and boron carbide. If the content of the boron compound is less than 1.0% by mass in terms of boron oxide, the above effect is difficult to obtain. On the other hand, when the content exceeds 10% by mass in terms of boron oxide, firing shrinkage increases. The reason for prescribing in terms of boron oxide is that boron nitride and boron carbide are also changed to boron oxide by firing in air. The boron compound preferably has a median diameter (D50) of 0.1 to 40 μm, and more preferably 5.0 to 10 μm.

  Next, an embodiment of a method for producing an inorganic fibrous molded body according to the present invention will be described. In the method for producing an inorganic fibrous molded body according to the embodiment of the present invention, ceramic fibers, ceramic powder, colloidal silica, and boron nitride are respectively weighed so as to have the above blending ratio, added to water, and further organic A polymer flocculant is added as a binder to a concentration of 2% by mass in the slurry. This is mixed with a stirrer and dispersed to prepare a slurry. The slurry is subjected to wet suction molding to obtain a wet body having a predetermined shape, and then the wet body is dried in air at, for example, 110 to 130 ° C., and further in air, 1100 to 1400 ° C., preferably 1200 to 1300. Bake at ℃. Thereby, an inorganic fiber molded object is obtained.

  The inorganic fiber molded body of the embodiment of the present invention produced above has excellent wear resistance, low surface roughness, excellent heat spalling resistance, easy to handle, almost no foreign matter, voids, cracks, etc. Even if it is repeatedly used at a high temperature, there is almost no change in shape and the like, and it is excellent in workability. Therefore, it is suitable for applications such as disk rolls for manufacturing glass sheets, setters with excellent breathability and smoothness used for firing high-performance ceramics, and “bush molds” for glass bending such as automotive door mirrors. Yes. In addition, since there is no tumbling during use (the raw material powder falls from the surface of the inorganic fiber molded body, etc.), it can be applied to the furnace wall of an induction heating furnace.

  In addition, the disk roll is formed by superimposing a plurality of annular disks made of heat-resistant inorganic fibers and inserting a rotating shaft through the center part thereof. In the production of plate glass, it is heated to about 1600 ° C. Fused glass is sandwiched between a pair of rolls, pulled out of a furnace and formed into a plate shape, and the disk roll is used as the pair of rolls.

  A setter is a plate-shaped jig, and ceramics are used as shelf boards and floorboards for placing objects to be fired and placing them in a firing furnace in the firing process when manufacturing electronic parts and precision glass products. A setter made of steel is used. The metal mold is a mold having a predetermined curvature. In the manufacturing process of a bending mirror such as an automobile door mirror or cosmetic mirror, a glass material is placed on the glass mold, for example, 650-750. It has been performed that the glass material is deformed along the curved surface of the mold by heating to about ° C.

[Example 1]
Cordierite powder 83 of silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) as ceramic fiber in 10 liters of water and D50 of 12 μm. 0 parts by weight, colloidal silica was added in a weight ratio of 3.0 parts by weight in terms of solid content, and D50 was 4.0 parts by weight of boron nitride having a thickness of 5 μm. A slurry of 0.038 kg / m ³ was prepared. To this slurry, a polymer flocculant as an organic binder was added and aggregated so that the concentration in the slurry would be 2% by mass, and formed into a plate shape of 150 mm long × 150 mm wide × 30 mm thick by wet suction molding. The obtained plate-shaped molded body was dried in air at 120 ° C. and then fired in air at 1250 ° C. for 3 hours to obtain an inorganic fibrous molded body.

The obtained molded body was surface processed by a surface processing machine using a belt sander and peripherally processed by a band saw. When the bulk density of the molded body after processing was measured, it was 1200 kg / m ³ . While measuring the chemical composition, bending strength, surface roughness, thermal expansion coefficient, and heating linear shrinkage of the molded body after this processing, the 1000 ° C heat-resistant spalling test was repeated to check for foreign matter, voids, and cracks. The presence or absence was confirmed visually.

[Example 2]
Cordierite powder having 52.0 parts by weight of silica alumina fibers (Al ₂ O ₃ : 45% by mass or more, Al ₂ O ₃ + SiO ₂ : 98% by mass or more) as ceramic fibers in 10 liters of water, and D50 of 12 μm. 0 parts by mass, colloidal silica was added in a weight ratio of 2.0 parts by mass in terms of solid content, and D50 was 6.0 parts by mass of boron nitride having a thickness of 5 μm. A slurry of 0.016 kg / m ³ was prepared. Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1250 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. It was 500 kg / m ³ when the bulk density of the molded body after processing was measured. Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

"Example 3"
In 10 liters of water, silica alumina fiber (Al ₂ O ₃ : 45% by mass or more, Al ₂ O ₃ + SiO ₂ : 98% by mass or more) as ceramic fiber is 46.0 parts by mass and D50 is 12 μm cordierite powder 40. 0 parts by weight, colloidal silica was added in a weight ratio of 7.0 parts by weight in terms of solid content, and D50 was 7.0 parts by weight of boron nitride having a thickness of 5 μm. A slurry of 0.022 kg / m ³ was prepared. Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1200 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. The bulk density of the molded body after processing was measured and found to be 700 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 4]
In 10 liters of water, silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) as a ceramic fiber is 26.0 parts by mass, and cordierite powder with D50 of 12 μm is 26. 0 part by mass, 26.0 parts by mass of kaolin powder having a D50 of 9 μm, 12.0 parts by mass of spinel powder (MgO, Al ₂ O ₃ ) having a D50 of 23 μm, 6.0 parts by mass of colloidal silica in terms of solid content, D50 Were added in a weighted ratio of 4.0 parts by mass of boron nitride of 5 μm, and stirred for several minutes to prepare a slurry having a slurry concentration of 0.025 kg / m ³ . Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1300 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. When the bulk density of the molded body after processing was measured, it was 800 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 5]
In 10 liters of water, silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) 30.0 parts by mass, cordierite powder 31 having a D50 of 12 μm as ceramic fiber 31. 0 parts by mass, 31.0 parts by mass of kaolin powder having a D50 of 9 μm, 2.0 parts by mass of spinel powder (MgO, Al ₂ O ₃ ) having a D50 of 23 μm, 3.0 parts by mass of colloidal silica in terms of solid content, D50 Was added in a weighted ratio of 3.0 parts by mass of boron nitride of 5 μm, and stirred for several minutes to prepare a slurry having a slurry concentration of 0.022 kg / m ³ . Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1300 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. The bulk density of the molded body after processing was measured and found to be 700 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 6]
In 10 liters of water, silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) 28.0 parts by mass, cordierite powder 63 having a D50 of 12 μm as ceramic fibers 63. 0 parts by weight, 3.0 parts by weight of kaolin powder having a D50 of 9 μm, 2.0 parts by weight of spinel powder (MgO, Al ₂ O ₃ ) having a D50 of 23 μm, 2.0 parts by weight of colloidal silica in terms of solid content, D50 Were added in a weighted ratio of 2.0 parts by mass of boron nitride of 5 μm and stirred for several minutes to prepare a slurry having a slurry concentration of 0.033 kg / m ³ . Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1350 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. The bulk density of the molded body after processing was measured and found to be 1050 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 7]
A cordierite powder having 27.0 parts by weight of silica alumina fiber (Al ₂ O ₃ : 45% by mass or more, Al ₂ O ₃ + SiO ₂ : 98% by mass or more) as ceramic fibers in 10 liters of water, and D50 of 12 μm. 0 parts by weight, 3.0 parts by weight of kaolin powder with D50 of 9 μm, 13.0 parts by weight of spinel powder (MgO, Al ₂ O ₃ ) with D50 of 23 μm, 1.0 parts by weight of colloidal silica in terms of solid content, D50 Were added in a weighted ratio of 4.0 parts by mass of boron nitride of 5 μm, and stirred for several minutes to prepare a slurry with a slurry concentration of 0.032 kg / m ³ . Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1300 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. The bulk density of the molded body after processing was measured and found to be 1040 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 8]
In 10 liters of water, 31.0 parts by mass of cordierite powder having biodissolvable fibers (SiO ₂ : 70 to 80% by mass, CaO + MgO: 19 to 25% by mass) as ceramic fibers, and D50 of 12 μm, D50 is 9 μm of kaolin powder 31.0 parts by mass, colloidal silica is 4.0 parts by mass in terms of solid content, and D50 is 5 μm of boron nitride 4.0 parts by mass. A slurry having a slurry concentration of 0.031 kg / m ³ was prepared by stirring for several minutes. Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1300 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. It was 960 kg / m ³ when the bulk density of the molded body after processing was measured. Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 9]
In 10 liters of water, 20.0 parts by mass of alumina fibers (Al ₂ O ₃ : 72 to 100% by mass) as ceramic fibers, 37.5 parts by weight of cordierite powder having a D50 of 12 μm, and kaolin powder 37 having a D50 of 9 μm. 5 parts by mass, colloidal silica was added in a weight ratio of 1.0 part by mass in terms of solid content, and D50 was 4.0 parts by mass of boron nitride having a thickness of 5 μm. A 0.032 kg / m ³ % slurry was prepared. Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1350 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. When the bulk density of the molded body after processing was measured, it was 1030 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Example 10]
Silica fibers 10 liters of water as a ceramic fiber _(SiO 2: 75 to 100% by weight) 25.0 parts by mass, D50 is cordierite powder 30.0 parts by weight of 12 [mu] m, D50 kaolin powder 30.0 parts by weight of 9μm , D50 is 23 μm spinel powder (MgO, Al ₂ O ₃ ) 10.0 parts by weight, colloidal silica 2.0 parts by weight, D50 is 5 μm boron nitride 3.0 parts by weight. And stirred for several minutes to prepare a slurry having a slurry concentration of 0.028 kg / m ³ . Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1200 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. When the bulk density of the molded body after processing was measured, it was 900 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually. Table 1 below shows the compositions and measurement results of the inorganic fibrous molded bodies of Examples 1 to 10 described above.

[Comparative Example 1]
In 10 liters of water, silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) 66.0 parts by mass, cordierite powder 30 having D50 of 12 μm as ceramic fiber. 0 parts by mass, colloidal silica is added in a weight ratio of 2.0 parts by mass in terms of solid content, and D50 is 2.0 parts by mass of boron nitride having a thickness of 5 μm. A slurry of 0.012 kg / m ³ was prepared. Thereafter, molding and drying were performed in the same manner as in Example 1, and then fired at 1250 ° C. for 3 hours to obtain an inorganic fiber molded body.

When this molded body was subjected to surface processing and outer periphery processing in the same manner as in Example 1, it could be processed satisfactorily. When the bulk density of the molded body after processing was measured, it was 400 kg / m ³ . Moreover, while measuring a chemical component, bending strength, surface roughness, a thermal expansion coefficient, and a heating linear shrinkage rate with respect to the molded object after a process similarly to Example 1, 1000 degreeC heat-resistant spalling test was repeated. The presence or absence of foreign matter, voids, and cracks was confirmed visually.

[Comparative Example 2]
Silica alumina fiber (Al ₂ O ₃ : 45 mass% or more, Al ₂ O ₃ + SiO ₂ : 98 mass% or more) 5.0 parts by mass in 10 liters of water as a ceramic fiber, D50 of 12 μm cordierite powder 90. 0 parts by mass, colloidal silica is added in a weight ratio of 2.0 parts by mass in terms of solid content, and D50 is 3.0 parts by mass of boron nitride having a thickness of 5 μm. A slurry of 0.016 kg / m ³ was prepared. Thereafter, when molding was attempted in the same manner as in Example 1, the obtained molded body had cracks in visual confirmation after demolding, and therefore subsequent measurements (bending strength, surface roughness, thermal expansion coefficient, heating Linear shrinkage) and heat spalling test could not be performed. Table 2 below shows the compositions and measurement results of the inorganic fibrous molded bodies of Comparative Examples 1 and 2 described above.

From the results of Tables 1 and 2, the inorganic fibrous molded bodies of Examples 1 to 10 that satisfy the requirements of the present invention have high strength because the bending strength is 6 MPa or more, and the surface roughness is 9.5 μm or less. Therefore, it is effective as a die for bending glass, and the linear thermal expansion coefficient at RT (room temperature) to 700 ° C. is 4.6 × 10 ⁻⁶ / K or less and the heating linear shrinkage rate at 1000 ° C. × 24 hr. Is 0.3 or less, it can be seen that the heat spalling property is excellent. On the other hand, the inorganic fibrous molded body of Comparative Example 1 had a lower bending strength and a larger surface roughness and thermal expansion coefficient than Examples 1-10. In the heat-resistant spalling test, cracks occurred at the first time.

Claims (11)

The ceramic fiber content is 10 to 60% by mass, the colloidal silica content is 1.0 to 10% by mass in terms of solid content, and the boron compound content is 1.0 to 10% by mass in terms of boron oxide, remainder Ri ceramic powder (excluding boron compound) der containing at least MgO, the ceramic powder (other than boron compounds), cordierite powder, kaolin powder, and among the spinel powder, in that it comprises at least cordierite powder A featured inorganic fiber molded body.   The inorganic fiber molded body according to claim 1, wherein the ceramic fiber is at least one of silica fiber, alumina fiber, silica alumina fiber, and biosoluble fiber. The inorganic fibrous molded body according to claim 1 or 2 , wherein the boron compound is at least one of boron oxide, boron nitride, and boron carbide. The median size of the ceramic powder (D50), characterized in that a 0.1 to 40, an inorganic fibrous molded body according to any one of claims 1-3. The inorganic fibrous molded body according to any one of claims 1 to 4, wherein a bulk density is 500 to 1200 kg / m ³ . SiO ₂ is 30.0 mass% or more and 60.0 mass% or less, Al ₂ O ₃ is 20.0 mass% or more and 50.0 mass% or less, MgO is 3.0 mass% or more and 13.0 mass% or less, B the ₂ O _3, characterized in that it contains less 14.0 wt% to 1.4 wt%, the inorganic fibrous molded body according to any one of claims 1-5. Bending strength is 6 Mpa or more, The inorganic fibrous molded object of any one of Claims 1-6 characterized by the above-mentioned. The inorganic fiber molded body according to any one of claims 1 to 7 , wherein the surface roughness is 9.5 µm or less. The inorganic fibrous molded article according to any one of claims 1 to 8, wherein a hot linear expansion coefficient at RT to 700 ° C is 4.6 × 10 ^-6 / K or less. The inorganic fiber molded body according to any one of claims 1 to 9 , wherein a heat shrinkage at 1000 ° C x 24h is 0.3% or less. The ceramic fiber content is 10 to 60% by mass, the colloidal silica content is 1.0 to 10% by mass in terms of solid content, and the boron compound content is 1.0 to 10% by mass in terms of boron oxide, The balance is ceramic powder (excluding boron compounds) containing at least MgO, and SiO ₂ 30.0 mass% or more and 60.0 mass% or less, Al ₂ O ₃ 20.0 mass% or more and 50.0 mass% or less, MgO 3.0 mass% or more and 13.0 mass% or less, B ₂ O ₃ 1.4 to 14.0% by mass of an inorganic fibrous shaped article characterized by comprising: