JP3517577B2 - Coating method of high precision glass film on lightweight refractory - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method (coating method) for applying a highly accurate glass film on a lightweight refractory material.

[0002]

2. Description of the Related Art Inorganic fiber type lightweight refractory materials, such as those used in space shuttles, are disadvantageous in that they are very brittle and easily damaged. Therefore, the light weight refractory has been manufactured (coated) with a glass film to obtain a product (glass film-covered lightweight refractory).

[0003]

However, the glass film-coated lightweight refractory obtained by the conventional manufacturing method has many defective products in which irregularities exist on the surface of the glass film coating the lightweight refractory, resulting in a low yield. There was a problem. That is, when the surface of the glass film covering the lightweight refractory material has irregularities, it is not a good product because of increased air resistance during flight of the space shuttle and deterioration of appearance. Further, the adhesion strength of the glass film to the lightweight refractory is not sufficient, and the glass film may peel off from the lightweight refractory during handling.

The present invention solves the above-mentioned problems of the prior art and can adjust the glass film coating the lightweight refractory material to a desired shape (particularly, the glass film has a flat surface without irregularities). It is possible to form a shaped glass film to improve the yield), a method for coating a lightweight refractory with a glass film, a glass film-coated lightweight refractory, and a shape adjusting material for a lightweight refractory. . Another object of the present invention is to provide a method for coating a lightweight refractory with a glass film, which can improve the adhesion strength (peel strength) of the glass film to the lightweight refractory, a glass film-coated lightweight refractory and a lightweight refractory. The object is to provide a shape adjusting material.

[0005]

The present inventor has found that a lightweight refractory material is formed by pressing dry particles of a specific shape adjusting material onto the lightweight refractory material to form a glass film on the surface of the lightweight refractory material. That the glass film coating the can be adjusted to a desired shape, in particular, that even a lightweight refractory having a defect can form a glass film having a flat surface without unevenness, The inventors have found that the peeling strength of the glass film-coated lightweight refractory glass film thus obtained is remarkably improved, and have completed the present invention.

According to the present invention, the above object can be achieved by the following method for coating a glass refractory on a light-weight refractory, a glass-film-coated light-weight refractory and a shape-controlling agent for the light-weight refractory. That is, according to the first aspect of the present invention, in order to repair defects on the surface of the lightweight refractory, or
Protrusions of the desired shape are provided on the surface of a lightweight refractory material that has no defects.
As a shape adjusting material with an average particle size of 1 to 50 μm
A surface shape adjusting step of press-bonding the dry particles of the dry refractory material to the surface of the lightweight refractory material, and a glass film for forming a glass film by heat-treating the lightweight refractory material whose surface shape is adjusted in the surface shape adjusting step. A method of coating a glass film on a lightweight refractory material, which includes a forming step and includes, as the shape adjusting material, a shape adjusting material containing as a main component a starting material of a glass film formed by heat treatment in the glass film forming step.

Further, as a lightweight refractory for pressing dry particles of the shape adjusting material in the surface shape adjusting step, a lightweight refractory having a coating first layer containing a starting material for forming a glass film and an organic binder. A thing can be used. In the surface shape adjusting step, the coating first
Dry particles of the shape adjusting material can be pressure bonded to the lightweight refractory through a layer. Further, the surface shape adjusting step includes a filling step in which dry particles of the shape adjusting material are pressure-bonded and filled in a defect of the surface of the lightweight refractory material or a recess of the coating first layer that covers the defect. You can

In the surface shape adjusting step, the second coating layer is formed by pressing dry particles of the shape adjusting material onto the lightweight refractory to form a second coating layer containing the dry particles of the shape adjusting material. A layer forming step can be included. Further, in the surface shape adjusting step, the dry particles are pressed onto the surface of the lightweight refractory material.
After wearing, includes a surface layer forming step of forming a surface layer comprising a starting material and an organic binder to form a glass film, the starting material for forming a glass film in the surface layer is first the coating The same starting material as that for forming the one-layer glass film can be contained as a main component.

Further, as the shape adjusting material, a shape adjusting material containing a glass frit and a reaction hardening glass obtained by firing a crystal inhibitor of the glass frit as a main component can be used. Further, as the lightweight refractory, a high porosity lightweight refractory containing inorganic fibers as a main component can be used.

According to a second aspect of the present invention, there is provided a glass-film-coated lightweight refractory formed by forming a glass film on the lightweight refractory by the method for coating the lightweight refractory with the glass film. According to a third aspect of the present invention, according to claim 1 containing a reactive curing glass obtained by firing a crystal inhibitor of glass frit and the glass frit as the main component
The method for coating the glass film on the lightweight refractory described in
It is a shape adjusting material to be applied . In addition, in the present invention, the description of the numerical range includes not only both end values but also all arbitrary intermediate values included therein. Also, wt%
Means% by weight.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION [Method for Coating Lightweight Refractory Material with Glass Film] The method for coating a lightweight refractory material with a glass film includes a surface shape adjusting step and a glass film forming step.

[Lightweight refractory material] The lightweight refractory material that is the object of the coating method of the present invention has the following general characteristics.
Any material can be used as long as it can withstand the heat treatment temperature (coating film baking temperature) in the glass film forming step, and generally a ceramic material can be considered. For example, there is a porous lightweight refractory having high porosity in which inorganic fibers are bonded with a glassy binder phase. Further, U.S. Pat. No. 4,097,7
No. 71, a reusable surface insulating material (RSI) having a porous silica structure, a foamed silica sintered body, etc.
Some have fire resistance up to ℃ and low temperature resistance up to -100 ℃.

Other specific lightweight refractory materials include, for example, JP-A-62-9181 and JP-B-64-10.
No. 469, Japanese Patent Publication No. 5-72341, and Japanese Patent Laid-Open No.
No. 0-231453, Japanese Patent Publication No. 1-55222, Japanese Patent Application Laid-Open No. 4-119995, and Japanese Patent Publication No. 4-286.
There are lightweight refractories described in Japanese Patent No. 66, Japanese Patent Application Laid-Open No. 4-119959, Japanese Patent Application Laid-Open No. 6-172010, and the like.

[Surface shape adjusting step] The surface shape adjusting step is a step of adjusting the surface shape of the lightweight refractory, and includes a pressure bonding step of pressure-bonding dry particles of the shape adjusting material. As the lightweight refractory for pressing dry particles of the shape adjusting material in the crimping step, a lightweight refractory having a coating first layer containing a starting material for forming a glass film and an organic binder is preferably used. In addition, in the pressure bonding step, preferably, dry particles of the shape adjusting material are pressure bonded to the lightweight refractory through the first coating layer.

The starting material for forming the glass film may be any material that can form a glass film by heat treatment in the glass film forming step, and generally has an average particle size of 1 to 50 μm (preferably 1 to 50 μm). Particles having a particle size of 30 μm) can be preferably used. As the organic binder, one that can maintain the shape of the first coating layer can be used, and preferably methyl cellulose, ethyl cellulose, polyvinyl alcohol, or the like can be used.

The weight ratio range of starting material: organic binder for forming the glass film in the first coating layer is preferably 30-50: 2-20 (more preferably 32-32).
40: 5-10). The content of the starting materials for forming the glass film in the coating first layer is preferably 30.
To 50% by weight (more preferably 32 to 40% by weight). The content of the organic binder in the first coating layer is preferably 2 to 20% by weight (more preferably 5 to 10% by weight). The coating first layer is preferably formed by applying a slurry containing particles of a starting material for forming a glass film, an organic binder and an organic solvent to a lightweight refractory and then drying (ie, removing the organic solvent. Make it what you got. Particles of the starting material for forming the glass film, which are insoluble in the organic solvent, preferably have a particle size of 1 to 50 μm (more preferably 1 to 30 μm). Before applying the slurry to the lightweight refractory, preferably, the surface of the lightweight refractory to be applied with the organic solvent such as ethanol is sufficiently wetted.

In the method for coating a lightweight refractory material with a glass film according to the present invention, in particular, scratches (for example, a width of about 10 mm or less) or cavities (for example, the diameter of a void is about 10 mm or less) are formed on the surface.
It can be applied to a lightweight refractory having defects such as, and the surface shape can be adjusted so as to repair the defects (make the defects flat).

It should be noted that the lightweight refractory has a huge defect (for example,
If the voids have a defect of more than 10 mm), a suspension slurry composed of a crushed or ground homogeneous refractory material and a solvent such as ethanol is embedded in the defective portion and dried to be flattened in advance. The method for coating a lightweight refractory with a glass film of the present invention is applied to the placed lightweight refractory.

Further, the method of coating a glass film on a lightweight refractory material of the present invention is applied to a lightweight refractory material having no defects as described above, and a convex portion having a desired shape is provided at a desired position on the light refractory material surface. The shape can be adjusted to a desired shape.

Preferably, dry particles of the shape adjusting material are pressure-bonded to the lightweight refractory through the coating first layer to adjust the surface shape of the lightweight refractory to a desired shape. If there are defects on the surface of the lightweight refractory,
Defects on the surface of the light-weight refractory or recesses in the first coating layer for covering the defects may be filled with dry particles of the shape adjusting material by pressure bonding to adjust the surface shape of the light-weight refractory to be flat. it can.

As a means for crimping the dry particles of the shape adjusting material to the lightweight refractory material, for example, a powder composed of the dry particles of the shape adjusting material is rubbed on the lightweight refractory material with the fingertips of a hand (wearing vinyl gloves). There is a means of crimping. When a light-weight refractory is provided with a coating first layer containing a starting material for forming a glass film and an organic binder, a powder composed of dry particles of a shape adjusting material is applied to a fingertip of a hand (wearing vinyl gloves). The light-weight refractory can be easily crimped by rubbing it through the coating first layer.

Further, dry particles of the shape adjusting material are pressure-bonded to the lightweight refractory material (including both the lightweight refractory material having the coating first layer and the lightweight refractory material having no coating first layer). The surface shape of the lightweight refractory material can be adjusted to a desired shape by forming a coating second layer containing dry particles of the shape adjusting material. The coating second layer is preferably 90% by weight of dry particles of the shape adjusting material so as not to separate from the coating first layer after the heat treatment in the glass film forming step.
The above content (more preferably 95% by weight or more, most preferably 100% by weight) can be included.
The thickness of the second coating layer (thickness before heat treatment) is preferably 0.05 to 1 mm (more preferably 0.05 to 1 mm).
0.5 mm), for example, it can be formed with a thickness of 0.1 mm or less.

When there are defects on the surface of the lightweight refractory material, preferably, the coating second layer covers the defects or the recesses of the coating first layer which cover the defects. The surface profile can be adjusted to repair the recess (eg, by providing the coating second layer with a thickness such that the defect or the recess is flat). In this case, the thickness of the coating second layer (thickness before heat treatment) can be, for example, 0.1 mm or less, and more preferably, the thickness of the entire glass film obtained after the heat treatment in the glass film forming step. Is preferably 0.2 to 0.4 mm, and the coating second layer is provided in such a thickness.

The surface shape adjusting step preferably includes a surface layer forming step of forming a surface layer containing a starting material for forming a glass film and an organic binder after the pressure bonding step. The starting material for forming the glass film in the surface layer is the same as the starting material for forming the glass film in the first coating layer (preferably having the same average particle size) as a main component (preferably Is 90% by weight or more,
More preferably 95% by weight or more, most preferably 100%
% By weight). As the organic binder in the surface layer, the organic binder that can be used in the first coating layer can be used.

The surface layer basically comprises the coating first layer.
It can be formed by the same means as the layer. That is, the weight ratio of the starting material: organic binder for forming the glass film in the surface layer and the range of the content ratio thereof may be the same as those of the coating first layer. Further, the particle size of the particles of the starting material for forming the glass film, which are not dissolved in the organic solvent, may be the same as that of the coating first layer. The surface layer is a lightweight refractory material (preferably a portion of the lightweight refractory material to which dry particles of the shape-controlling agent are pressure-bonded), which is a slurry containing a starting material particle for forming a glass film, an organic binder and an organic solvent. It can be obtained by coating and drying (that is, by removing the organic solvent).

In the present invention, the shape adjusting material is mainly composed of the starting material of the glass film formed by heat treatment in the glass film forming step (preferably 90% by weight or more, more preferably 95% by weight or more, and further preferably (99% by weight or more)
A shape adjusting material including is used. The shape adjusting material is a starting material of the glass film formed by heat treatment in the glass film forming step.
It is possible to use one containing 100% by weight. The shape-adjusting material can contain 20% by weight or less (more preferably 2 to 20% by weight, further preferably 5 to 10% by weight) of an organic binder, or can contain no organic binder. .

The shape adjusting member is dry particles (Rights Hitoshitsubu径1-5
0 .mu.m, good Mashiku average particle size 1 to 30 [mu] m, more preferably used in the form of an average particle size of 1 to 10 [mu] m). The dry particles of the shape-regulating material may be at least dry particles containing the starting material of the glass film formed by heat treatment in the glass film forming step, and further, additives to the glass film (for example, color pigments) and organic compounds. It can be a dry particle containing one or more binders. For example, it can be a primary particle consisting of only particles of the starting material of the glass film (including one having an organic binder attached thereto), or a secondary particle consisting of a plurality of particles of the starting material (usually The secondary particles are combined with an organic binder to form secondary particles, but secondary particles without an organic binder are also included). The dry particles of the shape adjusting material are, for example, dried by a slurry containing particles of a starting material for forming a glass film, an organic binder, and an organic solvent (that is, the organic solvent is removed) to form a powder. It can be obtained by processing (for example, crushing). The dried particles of the shape adjusting material are secondary particles obtained by combining particles of an additive (for example, a coloring pigment) to the glass film (a plurality of particles of the additive to the glass film are bound by, for example, an organic binder). (Including existing ones)
Along with that, it can be crimped to a lightweight refractory.

The main component of the shape adjusting material (that is, the starting material of the glass film formed by heat treatment in the glass film forming step) is preferably obtained by firing a glass frit and a crystal inhibitor for the glass frit. Reaction cured glass can be used.

[Glass Film Forming Step] The glass film forming step is a step of forming a glass film by heat-treating the lightweight refractory material whose surface shape is adjusted in the surface shape adjusting step. That is,
The dry particles of the specific shape control agent, which are pressure bonded to the lightweight refractory, contain the starting material of the glass film, and become the glass film or a part thereof by the heat treatment in this step. Since the specific coating first layer, the specific coating second layer and the specific surface layer each also contain the starting material of the glass film, when the lightweight refractory material has at least one of them, Becomes a part of the glass film (usually one glass film) by the heat treatment in this step. The organic binder burns and burns out.

According to the method for coating a lightweight refractory with a glass film according to the present invention, the center line average roughness Ra (JIS B
In the case of 0601), the surface of the glass film can be made smooth by about 0.005 to 0.2. The conditions of the heat treatment (for example, the temperature rising rate, the holding time at the maximum temperature, the temperature falling rate, the type of atmosphere, etc.) can be appropriately set according to the type of the glass film to be formed.

[Glass film-coated lightweight refractory material] The glass film-coated lightweight refractory material of the present invention is formed by forming a glass film on a lightweight refractory material by the method for coating a lightweight refractory material of the present invention with a glass film. . The thickness of the glass film is preferably 0.2 to 0.4 mm. Further, the peel strength between the lightweight refractory and the glass film coated with the glass film of the present invention is also related to the type of the lightweight refractory that forms the glass film (roughness, pore diameter, surface state of porosity). However, as a lightweight refractory material, inorganic fibers are bound by a binder (substantially amorphous silica fiber is the main inorganic fiber, alumina fiber, aluminosilicate fiber, aluminoborosilicate fiber A lightweight refractory containing one or a plurality of fibers as reinforcing inorganic fibers and having fibers fused by using at least one of borosilicate and alumina borosilicate as a binder (particularly, a bulk density of 0.12 g / cm ³ hereinafter, and when the tensile strength in the height direction is used is one)) is 2.5 kgf / cm ² or more, preferably 2.5 kgf / cm ² or more, more preferably 3k It is the f / cm ² or more, 4.3kgf /
It can be at least cm ² .

The "height direction" in the tensile strength in the height direction means the pressing direction at the time of molding, and usually means the axial direction of the press machine used for molding.
For example, the direction is orthogonal to the pressing surface of the molded body obtained by the pressing device. 1 kgf / cm ² =
It is 0.098 MPa.

[Preferable lightweight refractory material] A lightweight refractory material used in the method for coating a glass film on the lightweight refractory material of the present invention,
Further, the lightweight refractory in the glass film-coated lightweight refractory of the present invention is preferably composed of inorganic fibers bound by a binder. A more preferred lightweight refractory is
A substantially amorphous silica fiber as a main inorganic fiber,
One or more of alumina fibers, aluminosilicate fibers, and aluminoborosilicate fibers are included as reinforcing inorganic fibers, and the fibers are fused by using at least one of borosilicate and alumina borosilicate as a binder. Lightweight refractory (more preferably, bulk density of 0.1
The tensile strength in the height direction is 2 g / cm ³ or less and is 2.
5 kgf / cm ² or more). Hereinafter, the lightweight refractory material and the manufacturing method thereof will be described in more detail.

The binder is preferably a binder formed at the interface between the boron nitride powder and the inorganic fiber by firing the inorganic fiber. The term “substantially amorphous” means that it is composed of only an amorphous material by X-ray diffraction. The substantially amorphous silica fiber is preferably 2.5 g / cm ^3.
The true specific gravity is 0.65 to 4 μm. The reinforcing inorganic fiber is preferably 2.5 to 4 g / cm ^3.
The true specific gravity is 0.65 to 4 μm. The boron nitride powder is preferably a hexagonal boron nitride powder that causes an oxidation reaction at 900 to 1200 ° C.

The lightweight refractory has a bulk density of 0.12 g /
cm ³ or less (preferably 0.11 g / cm ³ or less, more preferably 0.09~0.11g / cm ³⁾ at and tensile strength in the height direction 2.5 kgf / cm ² (approximately 0.
245 MPa) or more (preferably 0.294 MPa or more).

The inorganic fibers in the lightweight refractory material are preferably composed only of X-ray diffraction amorphous fibers, or mainly composed of X-ray diffraction amorphous fibers. For example, when the inorganic fiber is a silica fiber, it means that it is composed of only silica fiber which is amorphous by X-ray diffraction.
It means that a clear main peak of iO ₂ does not appear.

The light weight refractory material contains substantially 60 to 60% by weight of a substantially amorphous silica fiber (more preferably 85 to 75% by weight).
%), One or more of alumina fibers, aluminosilicate fibers, aluminoborosilicate fibers can be 10-40% by weight (more preferably 15-25% by weight).

The weight ratio of the inorganic fibers to the inorganic binder in the lightweight refractory is 3 to 7.5% by weight (more preferably 3 to 6% by weight, more preferably inorganic binder) based on the total weight of the inorganic fibers. Can be 3-5% by weight).

[Preferable lightweight refractory material manufacturing method] The preferable lightweight refractory material is a dispersion liquid (preferably a weakly acidic dispersion liquid) in which inorganic fibers and boron oxide forming raw material powder are dispersed.
Inorganic fiber including a step of forming an aggregate of the inorganic fibers in which the boron oxide-forming raw material powder is collected by adjusting the pH of 1. and a step of firing the aggregate formed body at a temperature of 1200 to 1400 ° C. It can be manufactured by the method for manufacturing a lightweight refractory material.

Preferably, the agglomerate is vacuum-formed to obtain an agglomerate compact. Preferably, the dispersion is adjusted to pH 4
By adjusting to 10 to 10 and changing the degree of aggregation of the inorganic fibers, the bulk density of the inorganic fiber-based lightweight refractory material obtained after firing is controlled. The dispersion is preferably
The pH is adjusted to a predetermined pH within the range of 4 to 10 corresponding to the bulk density of the inorganic fiber-based lightweight refractory obtained after firing. The inorganic fiber preferably contains substantially amorphous silica fiber as a main raw material, and an inorganic fiber containing one or more fibers of alumina fiber, aluminosilicate fiber, aluminoborosilicate fiber as an auxiliary raw material. To use.

As the boron oxide forming raw material powder, a non-metallic boride which is insoluble in water can be used, and examples of such boride include boron nitride (BN), boron carbide (B ₄ C), and boride. There are silicon (SiB ₄ , SiB ₆ ) and the like. Boron nitride is preferably used. As the boron nitride, hexagonal boron nitride or cubic boron nitride can be used, but inexpensive hexagonal boron nitride is preferably used.

When boron nitride powder is used as the boron oxide forming raw material powder, the weight of the boron nitride powder in the dispersion is preferably 3 to 7.5% by weight (more preferably, the total weight of the inorganic fibers). Is 3 to 6% by weight, more preferably 3 to 5% by weight). P of the dispersion
H is made weakly acidic (preferably pH 3 to 6).

A dried molded body is usually used as the molded body of the aggregate.

A preferred embodiment for producing a lightweight refractory that can be suitably used in the present invention by the method for producing an inorganic fiber-based lightweight refractory will be described below.

The above-mentioned lightweight refractory material is preferably produced by dispersing and mixing inorganic fiber and boron compound powder in water, vacuum forming, drying and firing at a temperature of 1200 to 1400 ° C.

As the above-mentioned inorganic fiber, a siliceous inorganic fiber having a small specific gravity is selected from the viewpoint of reducing the bulk density of the entire lightweight refractory material. Siliceous fibers, and 3 to 4 g / cm ³ alumina fibers are mainly used at about 2.0 g / cm ³ and fibrous lightweight refractory true specific gravity, aluminoborosilicate fibers 2.7 g / cm ³ Is lighter than
The siliceous fiber is preferably one containing 99% by weight or more of SiO ₂ .

The siliceous fiber contained in the lightweight refractory is not a silica vitreous fiber having a glass transition point but a silica amorphous in consideration of use in a high temperature atmosphere, rapid heating and rapid cooling. Quality fibers (substantially amorphous silica fibers,
The same shall apply hereinafter). However, since the silica amorphous fiber has a weak fiber itself, the lightweight refractory material contains one or more of alumina fiber, aluminosilicate fiber, and aluminoborosilicate fiber as a reinforcing inorganic fiber. It is desirable to improve the strength of the entire lightweight refractory. The alumina fiber is preferably Al ₂ O ₃
Of 96% by weight or more is used.

When the amorphous silica fiber is heated, it crystallizes to become cristobalite and the fiber itself becomes more brittle, and cristobalite undergoes a volume change accompanying a phase transition at around 250 ° C. Repeated heating and cooling of a lightweight refractory obtained using fibers causes cracking. Since the lightweight refractory material is also considered for use in rapid heating and rapid cooling as described above, generation of cristobalite and its volume change are not desirable. Therefore, when the lightweight refractory material is manufactured, it is necessary to keep the amorphous silica fiber amorphous even after heating and firing in the manufacturing process. Therefore, a crystallization suppressing material for silica is used.

Boron is well known as a material for suppressing crystallization of silica. In addition, boron also functions as an inorganic binder, reacts with silica to form borosilicate, and forms aluminoborosilicate with silica and alumina, which makes it possible to fuse between the inorganic fibers. Therefore, when using silica amorphous fibers, the inorganic binder should be a boron compound.

Although various compounds are known as boron compounds, metal borides not only have the possibility of crystallizing silica amorphous fibers, but also change the vitrification temperature of borosilicate and aluminoborosilicate. It is not desirable because it prevents fusion between the inorganic fibers. The boride of nonmetallic boron oxide (B ₂ 0 _3), boron nitride (B
N), boron carbide (B ₄ C), silicon boride (SiB ₄ , S)
iB ₆ ) and the like are known, but boron oxide is water-soluble and is not suitable for dispersion and mixing in water used in the above-mentioned production method. Boron nitride, boron carbide, and silicon boride can be used, but boron nitride is more preferable because it is easily available.

It is desirable that the diameter of the inorganic fiber is thin in order to reduce the bulk density of the lightweight refractory, but if it is too thin, the strength of the lightweight refractory as a whole will decrease, so that it is particularly 0.6.
About 5 to 4 μm (preferably 0.65 to 2.7 μm) is desirable.

The length of the inorganic fiber is not particularly limited, but if the length of the inorganic fiber is too long, it will be difficult to disperse it in water. Further, if the length of the inorganic fibers is too short, the entanglement between the inorganic fibers is reduced and the strength of the entire lightweight refractory material is reduced. Therefore, the length of the inorganic fiber is preferably about 1 to 30 mm.

Silica The ratio of amorphous fibers to reinforcing inorganic fibers (one or more of alumina fibers, aluminosilicate fibers, aluminoborosilicate fibers) is silica when ultra-light refractory is desired. If the weight ratio of the fibers is increased, and if the strength is desired, the reinforcing inorganic fibers may be increased, but the density of the lightweight refractory material is 0.12 g.
/ Cm ³ or less, the weight ratio of the amorphous silica fiber is 90 to 60% by weight (preferably 85 to 75% by weight).

The boron nitride added as the inorganic binder is 1
Oxidation when firing at 200 to 1400 ° C. to generate inorganic fibers and borosilicate or aluminoborosilicate to fuse the interface of the inorganic fibers, and thus the lightweight refractory suitable for the present invention by the above manufacturing method. The particle size of boron nitride used for manufacturing is 900 to 1200.
It is desirable that the particle size is such that the oxidation reaction occurs at around ℃.

When an oxidation reaction occurs at a temperature lower than 900 ° C., boron nitride is oxidized before it reacts with the inorganic fibers, and the generated boron oxide is sublimated, resulting in an insufficient amount of boron than a predetermined amount. This will cause the strength of the product to decrease. Further, in the case of boron nitride that oxidizes at a temperature higher than 1200 ° C., it is necessary to lengthen the maximum temperature holding time because the oxidation of boron nitride and the reaction with the inorganic fiber occur during the maximum temperature holding during firing, which is costly. Is disadvantageous to The most desirable is boron nitride, in which the most active oxidation reaction occurs at around 1000 ° C. Since boron nitride has a flat shape,
Since the average particle size varies greatly depending on the measuring method, the particle size of boron nitride used in the above-mentioned manufacturing method should be determined from the temperature at which the oxidation reaction occurs.

Boron nitride is added in an amount of about 3 to 7.5% by weight (more preferably 3 to 6% by weight, further preferably 3 to 5% by weight) based on the total weight of the inorganic fibers. If it is less than 3% by weight, the degree of fusion between the inorganic fibers is low and the bulk density is low, but the strength is insufficient. In particular, when silica amorphous fibers are used, unless the boron compound powder is added in an amount of 3% by weight or more, a part of the silica amorphous fibers is crystallized during sintering and the strength of the lightweight refractory material is significantly reduced. I will let you. Also,
This is because even if the boron compound powder is added in an amount of more than 7.5% by weight, the bulk density is only increased, and no increase in strength can be confirmed.

Since it is difficult to disperse the inorganic fiber in water as it is, it is once dispersed in a strong acid aqueous solution having a pH of about 1 to 2 with a stirring motor for 1 to 2 hours to adsorb a hydrophilic group on the surface of the inorganic fiber. After removing the strong acid aqueous solution, water is added and the inorganic fibers are stirred with a stirring motor for about 15 to 30 minutes. After that, the added water is removed, water is added again, and the inorganic fibers are stirred for about 15 to 30 minutes with a stirring motor, so that they can be uniformly dispersed in the water.

After adding water and stirring, the water is once removed because the inorganic fibers, especially the silica amorphous fibers, start to dissolve when they are dispersed in the strong acid aqueous solution for a long time. This is because the pH of the aqueous solution to be dispersed needs to be about 3 to 6. When the pH does not become higher than 3 after the two dehydrations, the same operation is performed until the pH becomes higher than 3.

The water used at this time may be tap water, but deionized water is preferred. In particular, when silica amorphous fibers are used, deionized water is used because alkali metals such as sodium, potassium, and magnesium and alkaline earth metals in tap water promote crystallization of the silica amorphous fibers. .

When dispersing the inorganic fibers in the strong acid aqueous solution and in the water, it is desirable to disperse the inorganic fibers in an amount of about 1 to 3% by weight based on the whole. Increasing the weight ratio of the inorganic fibers used for dispersion requires increasing the output of the stirring motor for dispersion, and the inorganic fibers may break short during dispersion, reducing the overall strength of the lightweight refractory. There is.

The boron nitride powder is dispersed in an aqueous solution having a pH of 3 to 6 by using a stirring motor and an ultrasonic cleaner. This is because, in part, boron nitride is well dispersed in the weakly acidic region, and secondly, it is matched with the dispersed inorganic fiber suspension. Dispersion of boron nitride is pH 3-6
It is desirable that the amount is 1.5 to 2.0% by weight based on the aqueous solution. After dispersing the boron nitride powder, the boron nitride suspension is added to the aqueous solution in which the inorganic fibers are dispersed and having a pH of more than 3, and mixed for about 30 minutes.

The inorganic fibers are dispersed in water in a weak acid range of pH 3 to 6, but the inorganic fibers change from the dispersed state to the aggregated state by changing the pH to the alkaline side. Agglomerated inorganic fibers act as a resistance like a buffer material during dehydration / molding, so by changing the degree of aggregation of inorganic fibers, the degree of resistance during molding is changed, and the resulting inorganic fiber molded body is Change the filling degree. That is, the more aggregated inorganic fibers, the greater the resistance during molding and the smaller the green density of the molded body.

Further, since boron nitride is collected in the aggregate of inorganic fibers, the interface of the inorganic fibers can be efficiently fused during firing, and the strength of the lightweight refractory can be improved.

Also, since the inorganic fiber aggregates are molded during molding, the orientation of the inorganic fibers can be suppressed. In general, when a molding method such as papermaking is used, there is a problem that the fibers are oriented perpendicular to the pressing direction due to the pressure and the tensile strength in the height direction is extremely weak. However,
According to the above-mentioned manufacturing method, since the orientation of the inorganic fibers can be suppressed, it is possible to obtain a lightweight refractory material that is strong against pulling in the height direction.

As a result, by controlling the pH of the mixed aqueous solution of the inorganic fiber and the boron nitride powder immediately before molding,
It is possible to control the green density of the molded body, the bulk density of the fired body, and further the strength. When the density of the lightweight refractory material that can be suitably used in the present invention is 0.120 g / cm ³ or less, the pH of the mixed suspension of inorganic fibers and boron nitride is
The pH may be adjusted to 4 or more, preferably pH 4 to
10 (more preferably pH 6-8). Even if the pH is adjusted to be more alkaline than pH 10, no decrease in bulk density can be confirmed, and process management such as waste liquid treatment becomes complicated.

The pH adjusting agent used for pH adjustment is preferably ammonia water or ammonium acetate, and metal hydroxides such as sodium hydroxide and potassium hydroxide crystallize silica amorphous fibers to give a fibrous lightweight fireproof material. This is not desirable because it significantly reduces the strength of the entire product.

The control of the bulk density of the lightweight refractory material is usually carried out by controlling the addition amount of the heat-resistant inorganic powder or the inorganic binder to be added or the degree of pressurization applied to the molded body. Even if the same raw material, the same formulation, and the same molding method are used, the bulk density of the obtained lightweight refractory can be changed only by adjusting the pH.

The pH-controlled mixed suspension of inorganic fibers and boron compound powder is dehydrated and molded by vacuum molding.
Then, it is dried at 80 to 110 ° C., and 1250 to 1400 ° C. which is higher than the temperature at which boron nitride is oxidized and reacts with the inorganic fibers.
Baking is performed (preferably 1300 to 1400 ° C.). Select the heating rate so that the temperature inside the molded body is uniform,
The temperature is raised to 100 to 250 ° C in 1 hour, that is, 100
~ 250 ° C / hr. (Preferably 100 to 200 ° C./h
r. ) Degree is desirable.

The holding time at the maximum temperature is 900 to 1200.
If boron nitride that causes an oxidation reaction at ℃ is used, it may be 1-2 hours. The atmosphere during firing should be an oxidizing atmosphere so that the inorganic fibers and boron nitride can easily form borosilicate or aluminoborosilicate during firing.

[Shape Adjusting Material for Lightweight Refractory Material] The shape adjusting material for a lightweight refractory material of the present invention contains a glass frit and a reaction-cured glass obtained by firing a crystal inhibitor of the glass frit as a main component (preferably Is 90% by weight or more, more preferably 95% by weight or more, further preferably 98% by weight
Above, most preferably 100% by weight). The crystallization inhibitor is preferably a compound containing boron. It should be noted that an organic binder may be contained as an accessory component in an amount of 20% by weight or less.

[Examples of Preferred Embodiments] In the following, as a starting material for forming a glass film, a reaction-hardened glass mainly composed of a high-silica glass frit and a crystal inhibitor for the glass frit is used (hence, the shape is As the adjusting material, a case of using a shape adjusting material containing the reaction-cured glass as a main component) will be described.

As a starting material for forming the glass film, a reaction-hardened glass mainly composed of a high-silica glass frit and a crystal inhibitor (preferably boron oxide powder) of the glass frit can be used. In addition, various pigments (for example, black pigments such as silicon borides) may be added. In this case, the ratio of boron oxide in the reaction-cured glass when boron oxide is used as the crystallization inhibitor is preferably 8 to 13% by weight. As the silicon boride used as the black pigment, silicon tetraboride or a mixture of one or more of silicon tetraboride and other silicon boride can be used.

In order to impart high temperature resistance and thermal shock resistance characteristics to the coating glass film, the glass frit as the main raw material is preferably a high silica glass frit. Generally, the silica content is preferably 96% by weight or more. The impurities contained in the glass frit are N
It is desirable that impurities that deteriorate the heat resistance of the glass of an alkali metal such as a and K or an alkaline earth metal such as Mg and Ca are not contained as much as possible, and most of the impurities are preferably boron oxide or alumina.

For the above-mentioned reason for the glass frit, the higher the silica content, the more desirable the silica content is, and there is a glass frit with a high silica content of 98% by weight silica, which is known as quartz glass. From the viewpoint of cost, it is possible to use a porous glass frit containing 96 wt% silica as a standard value. However, although alumina and boron oxide are acceptable as the main impurities contained in the glass frit,
It is preferable that the total amount of other impurities, especially those that deteriorate the heat resistance of the glass, be less than 1% by weight. Such impurities that reduce heat resistance include alkali metals such as Na and K, and Mg and Ca.
Such as alkaline earth metals, Fe, and Ti.

As a high-silica glass frit, Vycol glass manufactured by Corning Incorporated in the US is known. These high-silica glasses generally have an acid washing step for removing impurities in the manufacturing process and are acid-washed. There are porous glass having pores generated at that time and dense glass in which pores are removed by heat treatment after acid cleaning. If the heat treatment temperature (glass baking temperature) in the glass film forming process is set too high, the entire light weight refractory material is likely to be distorted, which causes inconvenience. It is desirable that the silica be high silica and at the same time be porous with high activity.

As the lightweight refractory used in the example of the present embodiment, those repeatedly used in a high temperature atmosphere are also intended. The higher the porosity is, the more preferable it is, but in consideration of the balance with strength, it is appropriate to use 80 to 90% by weight or more, preferably 90% by weight or more, and particularly 90 to 96% by weight. For that purpose, it is preferable to add a glass crystallization inhibitor so that the glass does not crystallize even when it is repeatedly used in a high temperature atmosphere.

Boron is known as a glass crystallization inhibitor, and boron oxide can be effectively used in the example of the present embodiment. Boron oxide added to porous silica glass frit with high silica is desirable to have high purity from the viewpoint of removing impurities in order to retain high temperature resistance and thermal shock resistance similar to glass frit. From the viewpoints of easiness and cost, it is preferable to use a high purity boron oxide powder of 5 nines (99.999% by weight or more).

Regarding the ratio of boron oxide to glass frit, US Pat. No. 4,093,771 recommends _{2 to} 4% by weight of B ₂ O ₃ . However, from the viewpoint of reducing the amount of strain, it is preferable to select B ₂ O _{3 in} which the ratio of boron oxide to the glass frit is 6% by weight or more, particularly 8 to 13% by weight. It should be noted that when the ratio of boron oxide to the glass frit is 8% by weight or more, the temperature at the time of heat treatment (at the time of glass baking) becomes appropriate and it is effective in reducing the strain amount
If it is higher than 13% by weight, the high temperature resistance tends to be deteriorated and it may be inappropriate, so caution is required.

In order to uniformly mix the glass frit and the high-purity boron oxide powder, the glass frit is uniformly dispersed in an aqueous solution of boron oxide in which the boron oxide powder is dissolved and dispersed in ion-exchanged water, and then the hot plate is used. Alternatively, the water is removed by stirring while heating with a mantle heater or the like. Further, after removing excess water in a drying oven, it is pulverized and classified with # 16 mesh. Mix the classified glass frit and boron oxide at 1000 to 1100 ° C.
The glass frit and the boron oxide are reacted by firing at the temperature of 2 hours. At a temperature lower than 1000 ° C., the reaction between glass frit and boron oxide is insufficient,
If the temperature is higher than 0 ° C., the glass frit and boron oxide will react and melt, which is inappropriate. After firing, it is ground with a ball mill and classified with # 330-300 mesh to obtain reaction-cured glass. If a mesh coarser than # 300 mesh is used in the classification, a reaction-hardened glass having a large average particle diameter is obtained, and a highly accurate glass coating film tends not to be formed. Moreover, the classification operation becomes complicated even if the mesh is classified with a finer mesh than the # 330 mesh.

Silicon boride was added to the reaction-cured glass obtained as described above, and ethanol as a dispersion medium and a 2 wt% methylcellulose aqueous solution as a binder were mixed in a ball mill for 3 to 6 hours to prepare a slurry (for forming a glass film). Slurry). Silicon boride is added to the reaction-cured glass in order to obtain a sufficient black glass film, but silicon boride is not added when it is not necessary to make the glass black. As silicon boride to be added, silicon tetraboride is preferable, and other silicon boride compounds such as silicon hexaboride, silicon dodecaboride or a mixture or complex thereof (including solid solution), or molybdenum disilicide. Can be used although the black color is not as good as that of silicon tetraboride. Silicon tetraboride is a special silicon boride compound.
Obtained in a grade of -1088.

Silicon boride (particularly silicon tetraboride as a main component) is prepared so as to be 2.5% by weight or more based on the total amount of the reaction-cured glass and the silicon boride compound. If the addition rate of the silicon boride compound is lower than 2.5% by weight, there is a tendency that a black color is formed or predetermined optical characteristics cannot be obtained. Further, since silicon tetraboride such as boron tetrasilicide is a special boron silicide compound and is an expensive raw material, it is not economically advantageous to use it in a large amount, and the most desirable one is 2.5 to 5. It is 0% by weight.

An organic solvent is suitable as a dispersion medium for forming a slurry. Lightweight refractories with glass membranes have a high porosity, especially those with a porosity of 80 to 90% or more are intended to absorb a large amount of dispersion medium, but have a high evaporation temperature such as water. With the medium, the dispersion medium that has penetrated into the lightweight refractory is difficult to evaporate, and the glass film tends to be damaged during heat treatment (glass baking) in the drying or glass film forming step. Further, when a dispersion medium such as water is used, it may react with silicon tetraboride and decompose, which is inappropriate. Although ethanol was selected as the dispersion medium in the examples of the present invention in view of the above points, the affinity of the glass frit, and the ease of availability, other volatile organic solvents such as methanol and isopropyl alcohol can also be used.

An organic binder is used for shape retention (up to firing) of the glass paste film obtained by coating the slurry on a lightweight refractory, and an aqueous solution of methylcellulose is added as an example. The concentration of the aqueous methylcellulose solution is not particularly limited, but if the concentration is high, it is difficult to prepare and it is disadvantageous. In the examples of the present invention, a standard 2% by weight aqueous solution of methylcellulose was adopted. In general, the aqueous methyl cellulose solution is basically dissolved in ethanol (mixed)
Not to do so, Methocel E, F, J, K manufactured by 3M Company in the United States
Methyl cellulose having a hydroxypropyl group, which has improved solubility in an organic solvent, such as SH type manufactured by Shin-Etsu Chemical Co., Ltd. is preferable. As the organic binder for retaining the shape of the frit slurry, other known materials such as ethyl cellulose and polyvinyl alcohol can be used.

The slurry obtained as described above was filled in a spray gun, and the compressor pressure was set to 4 kgf / c.
m ² or less, to set the pressure when the trigger is pulled the spray gun so that the 3 kgf / cm ² or less. If spray coating is performed at a pressure higher than this, in the case of a general-purpose spray gun used, care should be taken as the compressed air from the spray gun may cause the coating surface to wavy and it may not be possible to apply a highly accurate coating film. . It is preferable that the lightweight refractory to be coated with the slurry be sufficiently wet with the same ethanol as that used for the slurry in advance. Since the lightweight refractory is porous, spray coating it while it is dry will only absorb ethanol, which is the solvent, into the lightweight refractory, which will roughen the coating surface.

After the spray coating, the product was dried at room temperature for a predetermined time (for example, 16 hours or more) to remove ethanol, and then dried in an oven at a predetermined temperature (for example, 70 ° C.) (for example, 3 hours or more), and the remaining solvent was used. Sufficiently remove (ethanol).

The above-mentioned slurry (slurry for forming a glass film) is dried on a lightweight refractory having the first coating layer (dry layer containing reaction-cured glass particles, silicon boride and methylcellulose) formed as described above. Powder form (preferable particle size is 1 to 50 μm, more preferable particle size is 1 to 30)
The powder obtained by processing into (μm) is pressed. The drying temperature for obtaining the powder from the slurry is preferably 40.
To 100 ° C (more preferably 50 to 70 ° C). In the case of a lightweight refractory having defects, a coating second layer made of the powder is preferably provided on the entire surface of the coating first layer with a thickness (for example, 0.1 mm or less) that covers the defects.

The slurry is applied to the lightweight refractory material having the second coating layer formed thereon. Preferably, the slurry is filled in a spray gun, and the spray pressure is such that the coating second layer is not destroyed (pressure when the trigger of the spray gun is pulled), preferably 2.0 to 3.5 kgf / cm ^2.
(More preferably 2.5 to 3.0 kgf / cm ² ) by spray coating the slurry.

After the spray coating, the product is dried at room temperature for a predetermined time (for example, 16 hours or more) to remove ethanol, and then dried (for example, 3 hours or more) in an oven at a predetermined temperature (for example, 70 ° C.) to leave the remaining residue. The solvent (ethanol) is sufficiently removed to form the surface layer.

When the reaction-cured glass and the black pigment such as silicon boride are used as the starting material for forming the glass film, the heat treatment in the glass film forming step is preferably nitrogen gas, argon gas or other inert gas. It is performed by gradual heating and gradual cooling in a gas atmosphere.

The heat treatment temperature (the baking temperature of the glass film) for heat-treating the lightweight refractory material having the surface layer formed thereon (the baking temperature of the glass film) is preferably a holding temperature of 1200 to 1260 ° C., preferably 1 to 3 hours. (More preferably 1 to
Hold for 2 hours. The rate of temperature increase up to the holding temperature is preferably 200 to 800 ° C / hour (more preferably 500 to 650 ° C / hour). The rate of temperature decrease from the holding temperature to room temperature is preferably 10 to 30 ° C./hour (more preferably 15 to 2) in the temperature range of 980 ° C. or higher.
5 ° C./hour), and preferably 200 to 800 ° C./hour (more preferably 300 ° C.) in the temperature range of less than 980 ° C.
˜600 ° C./hour).

[0091]

Example: Boron oxide powder (Furuuchi Chemical Co., Ltd. 5
N) Deionized water 272 cc obtained by heating 37 g to 85 ° C.
Completely dissolves in. In this aqueous solution of boron oxide, 137 g of ethanol (special grade reagent manufactured by Kanto Kagaku) and glass frit (Vycor # manufactured by Corning International Co., Ltd.)
7930, SiO _2: 96 wt%) is added 400 g.
Stir while keeping the temperature at 85 ° C on a hot plate to remove ethanol and water. When the slurry becomes too viscous to stir, remove residual ethanol and water in an oven at 70 ° C. Crush the finished dried product, #
Classify with 16 mesh and fill a silica container.
Bake at 0 ° C. for 2 hours. After firing, it is ground again and classified with # 330 mesh to obtain a reaction-cured glass.

234 g of reaction-cured glass, 6.0 g of silicon tetraboride (B-1088 manufactured by CERAC, USA), 386 g of ethanol, 2% aqueous solution of methyl cellulose (methyl cellulose: Metroze 65SH manufactured by Shin-Etsu Chemical Co., Ltd.)
-4500) 39.2 g is put into an alumina pot together with alumina boulders, and mixed for 5 hours on a pot stand to obtain a slurry for forming a glass film. Further, a part of the thus obtained slurry for forming a glass film is heated to 70 ° C.
It is dried in an oven and processed into powder.

The glass film forming slurry obtained by mixing by the above method was filled in a spray gun, and the compressor pressure was 3.0 kgf / cm ² , and the spray pressure was 2.
At 5 kgf / cm ² , a slightly curved plate-like (thickness of about 25 mm, width (short side) 200 mm, length (long side) 250 mm) lightweight refractory upper end surface (curvature radius R is as shown in FIG. 1). The coating is applied to a total of 5 surfaces (1000 mm convex surface) and 4 side surfaces, and the concave surface is not coated. At that time, the surface of the lightweight refractory material is sufficiently wetted with ethanol as a pretreatment for coating.

Subsequently, the glass film forming slurry is uniformly sprayed onto the entire surface of the lightweight refractory material to a thickness of 0.1 to 0.3 mm, and then dried at room temperature until the ethanol on the coating surface is completely evaporated. Therefore, in the surface shape adjusting step of the lightweight refractory, the powder (shape adjusting material) obtained by drying the slurry for forming the glass film is applied not only to the defective portion to be repaired on the lightweight refractory but also to the entire coating surface. Sprinkle it evenly and carefully finish it with your fingertips (wearing vinyl gloves) so that the coating surface is flat. Subsequently, the spray pressure was reduced to 1.0 kgf / cm ² to sufficiently moisten the entire surface, and then the spray pressure was adjusted to 2.5 kgf / cm ² until a predetermined thickness was reached, and the slurry for forming the glass film was coated. I do.

After coating, it was dried at room temperature for 16 hours,
Dry in an oven at 70 ° C. for 3 hours. The dried lightweight refractory material is placed in an atmosphere furnace, and nitrogen gas is supplied to the atmosphere furnace at a rate of 10 liters / minute from 30 minutes before heating to replace the atmosphere in the atmosphere furnace with nitrogen. After 30 minutes of gas inflow, heating was started and 610 ° C./hr. After heating at 1215 ° C. for 1 hour and 30 minutes, 600 ° C./hr. Cool in the furnace. The light-weight refractory material was obtained by the method for producing a light-weight refractory material to be described later, and the surface thereof was machined by a surface grinder to be smooth.

A glass film is formed on a lightweight refractory material without applying the method for coating a lightweight refractory material with a glass film according to the present invention (that is, in the same manner as above except that the step of adjusting the surface shape of the lightweight refractory material is not performed). When the glass film is formed, the smoothness of the surface of the glass film is the center line average roughness Ra (JIS B 0
In 601), it was only about 0.3 to 0.6. Also,
The peel strength of the glass film was only 2.6 kgf / cm ² .

On the other hand, the smoothness of the surface of the glass film when the method for coating a lightweight refractory material with a glass film according to the present invention is 0.005 in terms of the center line average roughness Ra.
It was possible to set it to 0.2. Further, the peel strength of the glass film could be improved to 4.3 kgf / cm ² .
The reason why the peeling strength is improved in this way is that the dry powder obtained by drying the glass film forming slurry in the surface shape adjusting step is pressure-bonded to the lightweight refractory, so that the inside of the lightweight refractory is covered with pores on the surface. It is considered that the dry powder (particles of the dry powder) was mixed in, and the contact area between the glass film and the lightweight refractory increased after the glass film was formed on the lightweight refractory. The peel strength of the glass film from the lightweight refractory material was measured as follows.

<Peeling Strength Measuring Method> While adhering the first jig to the glass film side of the light-weight refractory material via the adhesive, and also to the light-weight refractory side via the adhesive agent. A second jig is adhered, the first jig and the second jig are pulled in a direction perpendicular to the interface between the glass film and the lightweight refractory, and the peel strength is measured.

<Method for manufacturing lightweight refractory material> Silica amorphous fiber (Q-Fiber manufactured by Shuller Co., USA, purity: 99.7% by weight)
SiO ₂ , true specific gravity: 2.0 g / cm ³ , fiber diameter: 2 μm)
600 g was dispersed in 35 l of hydrochloric acid aqueous solution of pH 1 using a stirring motor to remove the strong acid aqueous solution. 35 l of deionized water was added to the silica amorphous fiber from which the strong acid aqueous solution was removed,
Disperse with a stirring motor for 20 minutes and remove the dispersion liquid.
Repeated times.

Alumina fiber (SAFFI manufactured by British ICI
L, purity: 96 wt% Al ₂ O ₃ , true specific gravity: 3.2 g / c
m ³ and fiber diameter: 3 μm) (150 g) were also dispersed in 25 l of an aqueous hydrochloric acid solution having a pH of 1 using a stirring motor to remove the strong acid aqueous solution. Similarly to the silica amorphous fiber, 25 l of deionized water was added to the alumina fiber from which the strong acid aqueous solution had been removed, and the operation of dispersing with a stirring motor for 20 minutes and removing the dispersion was repeated twice.

Hexagonal boron nitride powder (denkaboron nitride manufactured by Denki Kagaku Kogyo KK, average particle size: 7.3 μm, oxidation temperature: 950 ° C.) was mixed with the silica amorphous fiber and alumina fiber. 1.5 g of an aqueous solution in which 2 g is dispersed
After adding 1 liter and mixing for 30 minutes with a stirring motor, the pH was adjusted to 9.0 with concentrated aqueous ammonia (28% NH ₃ ).

After adjusting the pH, the product was dehydrated in a 36 × 36 (cm) vacuum forming machine to dehydrate and mold the molded product to a height of 8.5 cm, and dried at 100 ° C. After drying, the molded body was fired in an air atmosphere at 1300 ° C. for 1.5 hours to obtain a lightweight refractory material. This lightweight refractory has a bulk density of 0.085 g / c
m ³ , tensile strength (thickness direction) is 3.5 kgf / cm ² , and thermal conductivity is 0.21 W / m · K.

[0103]

The method for coating a lightweight refractory material with a glass film according to claims 1 to 8 repairs defects on the surface of the lightweight refractory material.
Or on the surface of a lightweight refractory that has no defects
In order to provide a convex portion having a desired shape, the average particle diameter is 1 to 50 μm.
Of dry particles as a shape adjusting material on the surface of lightweight refractory
And a surface shape adjusting step of adjusting the surface shape thereof, and a glass film forming step of forming a glass film by heat-treating the lightweight refractory whose surface shape is adjusted in the surface shape adjusting step, and as the shape adjusting material. Since the shape adjusting material containing as a main component the starting material of the glass film formed by heat treatment in the glass film forming step is used, the following basic effects can be achieved.

Since the glass film coating the lightweight refractory can be adjusted to a desired shape, a glass film having a flat surface without unevenness is formed on the surface of the glass film to form a glass film-coated lightweight refractory. The yield can be significantly improved. Further, the dry particles of the shape-adjusting material that has been pressure-bonded have entered the inside of the lightweight refractory from the pores, so after forming a glass film on the lightweight refractory, a glass film (the dry particles of the pressure-adjusting shape-adjusting material, After heat treatment for forming the glass film, it becomes a part of the glass film) and the contact area with the lightweight refractory increases, and the adhesion strength (peel strength) of the glass film to the lightweight refractory can be improved. . Such an increase in peel strength improves the handleability and impact resistance of the lightweight refractory material. For example, it is possible to improve handling when fixing a lightweight refractory to the outer surface of the space shuttle and reduce peeling or breakage of the glass film during handling,
Further, it is possible to improve impact resistance at the time of launching or entering the atmosphere, and reduce peeling or breakage of the glass film.

Since the method for coating a lightweight refractory material with a glass film according to claims 2 to 8 further comprises the constitutions specified in the claims, the above-mentioned basic effects are more remarkable.

A glass film for a lightweight refractory material according to claim 1.
The shape adjusting material according to claim 10 applied to the coating method, since it contains the reaction curing glass obtained by firing a crystal inhibitor of glass frit and the glass frit as the main component, a lightweight refractory of the present invention It can be suitably used for a method of coating a glass film on an object.

[Brief description of drawings]

FIG. 1 is a view of a slightly curved plate-shaped lightweight refractory to be coated with a glass film, as seen from a direction perpendicular to the thickness direction.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Kato 3-36 Noritake Shincho, Nishi-ku, Nagoya-shi, Aichi Noritake Company Limited Limited 36-72 (72) Kenji Yano Kenji Yano, Nishi-ku, Nishi-ku, Aichi No. 1-36 Noritake Company Limited (72) Inventor Kazuhiro Horimi No. 1-336 Noritake Shinmachi, Nishi-ku, Nagoya-shi Aichi Prefecture Noritake Company Limited (72) Inventor Yoshimoto Kato Aichi Noritake Company Limited 3-chome 1-36, Noritake Shinmachi, Nishi-ku, Nagoya (72) Inventor Takamitsu Isoya 3-36 Noritake Shincho, Nishi-ku, Nagoya-shi, Aichi Prefecture Noritake Company Limited (72) Inventor Masakazu Hiyoshi 3-1, 36 Noritake Shinmachi, Nishi-ku, Nagoya-shi, Aichi Noritake Company Limited (72) Inventor Takamitsu Fukui 3-36 Noritake Shinmachi, Nishi-ku, Nagoya-shi, Aichi Noritake Company Limited (56) Reference Japanese Patent Laid-Open No. 11-199352 (JP, A) JP-A-7-291770 (JP, A) JP-A-5-221755 (JP, A) JP-A-63-72786 (JP, A) JP-A-59-174585 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 41/80-41/91

Claims (10)

(57) [Claims] 1. To repair defects on the surface of a lightweight refractory material
Or a desired shape on the surface of a lightweight refractory without defects
The shape of the average particle size of 1 to 50 μm
A surface shape adjusting step of pressing dry particles as a conditioning material onto the surface of the lightweight refractory material to adjust the surface shape, and a heat treatment of the lightweight refractory material whose surface shape is adjusted in the surface shape adjusting step. A light weight including a glass film forming step of forming a glass film, wherein the shape adjusting material is a shape adjusting material containing as a main component a starting material of a glass film formed by heat treatment in the glass film forming step. A method for coating a refractory with a glass film. 2. A light weight refractory having a coating first layer containing a starting material for forming a glass film and an organic binder as a light weight refractory to which dry particles of the shape control material are pressure-bonded in the surface shape adjusting step. 2. The method for coating a lightweight refractory material with a glass film according to claim 1, wherein the material is used. 3. The lightweight refractory material according to claim 2, wherein dry particles of the shape regulating material are pressure-bonded to the lightweight refractory material through the coating first layer in the surface shape adjusting step. Glass coating method. 4. The surface shape adjusting step is a filling step of filling dry particles of the shape adjusting material by pressure bonding into defects on the surface of the lightweight refractory material or recesses of the coating first layer for covering the defects. 4. The method for coating a lightweight refractory material with a glass film according to claim 1, comprising: 5. The coating second step of forming the coating second layer comprising the dry particles of the shape adjusting material by pressure bonding dry particles of the shape adjusting material to the lightweight refractory in the surface shape adjusting step. The method for coating a lightweight refractory material with a glass film according to any one of claims 1 to 4, further comprising a layer forming step. 6. The surface shape adjusting step removes the dried particles.
A surface layer forming step of forming a surface layer comprising a starting material for forming a glass film and an organic binder after pressure bonding to the surface of the lightweight refractory, and a starting layer for forming the glass film in the surface layer. The glass film for a lightweight refractory material according to any one of claims 2 to 5, characterized in that the material contains, as a main component, the same starting material for forming the glass film of the coating first layer. Coating method. 7. The shape adjusting material containing a glass frit and a reaction hardening glass obtained by firing a crystal inhibitor of the glass frit as a main component is used as the shape adjusting material. 7. The method for coating a lightweight refractory material with a glass film according to any one of to 6. 8. The lightweight refractory according to claim 1, wherein the lightweight refractory comprises a high porosity lightweight refractory containing inorganic fibers as a main component. Method. 9. A lightweight refractory coated with a glass film, which is formed by forming a glass film on the lightweight refractory by the method for coating a lightweight refractory according to any one of claims 1 to 8. 10. A light refractory material according to claim 1, which contains a glass frit and a reaction-cured glass obtained by firing a crystal inhibitor of the glass frit as a main component. A shape adjusting material applied to a method of coating a glass film on a glass.