JP5014779B2 - Inorganic fiber molded body, inorganic fiber fired body, amorphous inorganic fiber composition, and amorphous inorganic fiber fired body - Google Patents

Description

  The present invention is, for example, an inorganic fiber molded body used as a heat insulating material in a heat treatment apparatus, an industrial kiln furnace or an incinerator, or a disk roll described in JP-A No. 2004-263860. An inorganic fiber molded body used as a base material for a high-temperature material transporting jig called a heat-resistant setter, which is described in a base material for a high-temperature material transporting roll or Japanese Patent Application Laid-Open No. 2003-292380, etc. The present invention relates to an inorganic fiber fired body, an amorphous inorganic fiber composition, and an amorphous inorganic fiber fired body.

  Inorganic fiber heat insulating materials (hereinafter also referred to as heat insulating materials) formed by binding inorganic fibers with a binder are lighter and easier to handle than castable refractory materials and have excellent heat insulation properties. It is used for applications that require heat resistance and heat insulation such as furnaces. (Patent Document 1)

  Such an inorganic fibrous heat insulating material occupies the main component of the constituent material with inorganic fibers, has many voids, and has a low density. Therefore, if the inorganic fiber contracts due to heating, the inorganic fibrous heat insulating material itself contracts under the influence. Such heat shrinkage may widen the joints between the heat insulating materials and lower the heat insulating efficiency, or may cause the heat insulating material to crack.

  The aluminosilicate fiber which is essentially amorphous causes crystallization when heated to a high temperature of about 900 ° C. or higher in a use state, and mullite and cristobalite are generated in the fiber. And, as the amount of mullite generated increases, large shrinkage occurs.

  In recent years, biosoluble inorganic fibers have been developed in consideration of the environment. Since such a biosoluble inorganic fiber generally contains MgO or CaO in its composition, it tends to be crystallized at a relatively low temperature of about 900 ° C., and the heating linear shrinkage rate of the fiber itself increases. In addition, since the inorganic fibrous heat insulating material contains colloidal silica or the like as a constituent material, the heat shrinking of the heat insulating material is concerned because the heat shrinks itself.

  As a measure to reduce the heating line shrinkage of the inorganic fibrous heat insulating material, the fiber is heated to a temperature higher than the crystallization temperature in advance and calcined cotton is used, or the formed inorganic fibrous heat insulating material is previously heated to a temperature higher than the crystallization temperature of the fiber However, there is a problem in that the heating process occurs and the cost is increased.

On the other hand, JP-A-56-92155 contains unexpanded vermiculite, an inorganic fibrous material and a binder, has a maximum negative expansion percentage of about 10% at about 300 ° C., and at about 350 ° C. A flexible inflatable sheet for use in an automotive contact converter monolith returning to its original starting thickness or higher is disclosed. The unexpanded vermiculite blended in the expandable sheet expands itself by heating. Therefore, it is also possible to reduce the heating line shrinkage of the inorganic fibrous heat insulating material by adding unexpanded vermiculite.
JP 2001-335379 A JP 56-92115 A

  However, unexpanded vermiculite has a heat resistance of only about 800 ° C., and cannot be used as a heat insulating material in an environment exceeding 1000 ° C., for example, in a heat treatment apparatus, an industrial kiln furnace, or an incinerator.

  Accordingly, an object of the present invention is to provide an inorganic fibrous shaped article and an amorphous inorganic fibrous composition having small dimensional shrinkage during heating or firing even when used as a heat insulating material in an environment exceeding 1000 ° C. and the same. An object of the present invention is to provide an inorganic fiber fired body and an amorphous inorganic fiber fired body that are fired.

  In such a situation, the present inventors have conducted intensive studies, and as a result, blended at least two types of reactive inorganic powders that expand in volume by heating or firing in an inorganic fiber molded body or an amorphous inorganic fiber composition. As a result, even when used as a heat insulating material in an environment exceeding 1000 ° C., the dimensional shrinkage at the time of heating or baking is small, and the heat insulating material is not cracked, and the present invention is completed. It came to.

That is, the present invention comprises 50 to 98% by mass of inorganic fibers composed of silica-alumina-based biosoluble fibers containing CaO and MgO , 1 to 20% by mass of binder, and 1 to 30% by mass of reactive inorganic powder. An inorganic fibrous molded body containing, wherein the reactive inorganic powder includes at least one first reactive inorganic powder selected from calcium carbonate and magnesium carbonate, zirconium silicate, zirconium oxide, titanium oxide, and One or more second reactive inorganic powders selected from aluminum hydroxide, and these reactive inorganic powders provide an inorganic fibrous molded body having the property of reacting by firing to expand in volume. is there.

  The present invention also provides an inorganic fibrous fired body obtained by firing the inorganic fibrous molded body, wherein the reactive inorganic powder reacts and expands in volume. To do.

Moreover, this invention is 50-98 mass% of inorganic fiber which consists of a silica alumina type biosoluble fiber containing CaO and MgO in solid content conversion, 1-20 mass% of binders , and reactive inorganic powder 1 together and a 30 mass%, a amorphous inorganic fibrous composition comprising solvent, the reactive inorganic powder, at least, one or more first reactive inorganic selected from calcium carbonate and magnesium carbonate Including a powder and one or more second reactive inorganic powders selected from zirconium silicate, zirconium oxide, titanium oxide, and aluminum hydroxide, and these reactive inorganic powders react by firing to expand in volume. The present invention provides an amorphous inorganic fibrous composition characterized by having properties.

  The present invention also provides an amorphous inorganic fibrous material obtained by firing the amorphous inorganic fibrous composition, wherein the reactive inorganic powder reacts and expands in volume. A fired body is provided.

  The present invention is an inorganic fiber molded article, an amorphous inorganic fiber composition, and an amorphous inorganic fiber composition with small dimensional shrinkage during heating or firing even when used as a heat insulating material in an environment exceeding 1000 ° C. And an amorphous inorganic fibrous fired body can be provided.

  The inorganic fibrous molded body of the present invention contains inorganic fibers, a binder, and at least two types of reactive inorganic powders. The blending amount of these constituent materials is not particularly limited as long as the inorganic fiber molded body can be suitably produced. In the inorganic fiber molded body, the inorganic fiber is 50 to 98 mass%, the binder is 1 to 20 mass%, and the reactive inorganic powder. The body may be 1 to 49% by mass.

  In the present invention, the reactive inorganic powder has a property of volume expansion by reacting two or more kinds of reactive inorganic powders by heating or firing, preferably at a temperature of 800 to 1100 ° C. That is, two or more types of reactive inorganic powders react to generate an inorganic powder having a volume larger than the total volume of the reactive inorganic powder before the reaction. Examples of such a reaction include a spinel reaction in which a first reactive inorganic powder and a second reactive inorganic powder react to generate spinel. In this case, the first reactive inorganic powder includes a compound containing at least one of calcium and magnesium. Examples of the compound include oxide, carbonate, hydroxide, acetate, nitrate, sulfuric acid. Examples include salts and chlorides. Examples of the second inorganic powder include a compound containing at least one of aluminum, zirconium, and titanium. Examples of the compound include oxide, carbonate, hydroxide, acetate, and nitrate. , Sulfates and chlorides.

  Specific examples of the first reactive inorganic powder include calcium carbonate and magnesium carbonate, and examples of the second reactive inorganic powder include zirconium silicate, zirconium oxide, titanium oxide, and aluminum hydroxide. It is done.

  In the present invention, there are two or more reactive inorganic powders to be used, but usually two to four types, preferably two types. The inorganic powder generated after the reaction is not necessarily one type, and other inorganic powders may be generated.

  By blending two or more types of reactive inorganic powders, two or more types of reactive inorganic powders react with each other and expand even if the inorganic fibers contained in the inorganic fiber molded body shrink somewhat due to heating or firing. Therefore, the shrinkage and the expansion are offset, and the heat shrinkage that occurs in the inorganic fiber molded body can be reduced. In addition, by appropriately designing the type and amount of inorganic fiber to be added and the type and amount of reactive inorganic powder, it can be expected that the heat shrinkage generated in the inorganic fiber molded body is zero as much as possible.

  Specific examples of the combination of the two types of reactive inorganic powders include those shown in Table 1. In Table 1, the generated inorganic powder is a reaction product of the first reactive inorganic powder and the second reactive inorganic powder.

In the present invention, the property of volume expansion upon reaction by firing or heating can be confirmed by the following laboratory method. That is, for example, when two types of reactive inorganic powder x and reactive inorganic powder y are used, first, the reactive inorganic powder x and the reactive inorganic powder y are uniformly in a weight ratio of 1: 1. The bar-shaped test piece having a density of 3000 to 5000 kg / m ³ is prepared at 5 mm × 5 mm × 20 mm. Next, firing is performed in an air atmosphere at a predetermined temperature in the range of 1100 ° C. for 8 hours, and the dimension (Z) mm of the fired body z is obtained. The volume expansion rate (%) is obtained by ((Z-20) / 20) × 100. In the present invention, the volume expansion coefficient is preferably 1 to 20%, particularly preferably 3 to 15%, when measured by the laboratory method. Note that the volume expansion coefficient is the reactive inorganic powder in the comparison between the reactive inorganic powder contained in the inorganic fiber molded body and the generated inorganic powder contained in the heated or fired inorganic fiber fired body. Since it is influenced by the components other than the above and the mixed state of the reactive inorganic powder, it is considered that the volume expansion coefficient is sufficient, but the effect of the present invention can be sufficiently obtained.

  The average particle diameter of the reactive inorganic powder is 0.1 to 100 μm, preferably 0.2 to 50 μm, particularly preferably 0.2 to 10 μm. If the average particle diameter is less than 0.1 μm, the inorganic fibrous molded body is liable to break during drying or firing, and if the average particle diameter exceeds 100 μm, the strength of the inorganic fibrous molded body is reduced. easy. The maximum particle size of the reactive inorganic powder is not particularly limited, but preferably 3 mm or less in consideration of dispersibility in the mixture or kneaded product. In addition, the aspect ratio (ratio between the minimum length and the maximum length) of the inorganic powder is usually less than 5.

  In the inorganic fibrous molded body of the present invention, the content of the reactive inorganic powder is 1 to 49% by mass, preferably 1 to 30% by mass, and particularly preferably 1 to 10% by mass. When n types (n is an integer) of reactive inorganic powders are used, the contents of the first reactive inorganic powder to the nth reactive inorganic powder are (1 to 49) / n% by mass, preferably (1-30) / n% by mass, particularly preferably (1-10) / n% by mass, and in particular, the first reactive inorganic powder to the nth reactive inorganic powder are The same amount is preferable in that a large volume expansion can be obtained with a small addition amount.

  The inorganic fiber used in the inorganic fiber molded body of the present invention is not particularly limited as long as it is not melted at 200 ° C. or higher, but is generally known as an inorganic fiber, aluminosilicate fiber, alkaline earth silicate fiber. Alumina silicate fiber, mullite fiber, rock wool and the like can be used, but aluminosilicate fiber can be suitably used from the viewpoint of heat resistance and availability.

  The inorganic fiber may be a biosoluble inorganic fiber having a physiological saline dissolution rate at 40 ° C. of 1% or more and a heat shrinkage rate at 1000 ° C. of 5% or less.

The physiological saline dissolution rate may be measured by the following measurement method. First, 1 g of a sample obtained by pulverizing inorganic fibers to 200 mesh or less and 150 ml of physiological saline are placed in an Erlenmeyer flask (300 ml) and placed in an incubator at 40 ° C. The Erlenmeyer flask is then subjected to horizontal shaking at 120 revolutions per minute for 50 hours. After shaking, the mixture is filtered, and the concentration (mg / L) of each element is measured by ICP emission analysis for silicon, magnesium, calcium and aluminum contained in the obtained filtrate. Then, the physiological saline dissolution rate C (%) is calculated from the concentration of each element and the content (mass%) of each element in the inorganic fiber before dissolution by the following formula (1). The concentration of each element obtained by ICP emission analysis is as follows: silicon element concentration: a1 (mg / L), magnesium element concentration: a2 (mg / L), calcium element concentration: a3 (mg / L) and The aluminum element concentration a4 (mg / L), the content of each element in the inorganic fiber before dissolution, silicon element content: b1 (mass%), magnesium element content: b2 (mass%), Calcium element content: b3 (mass%) and aluminum element content: b4 (mass%).
C (%) = {filtrate amount (L) × (a1 + a2 + a3 + a4) × 100} / {amount of inorganic fiber before dissolution (mg) × (b1 + b2 + b3 + b4) / 100} (1)

The biologically soluble inorganic fiber is not particularly limited as long as it is an inorganic fiber having a physiological saline dissolution rate at 40 ° C. of 1% or more and a heat shrinkage rate at 1000 ° C. of 5% or less. SiO ₂ 59.9 to 80% by mass, Al ₂ O ₃ 0.1 to 3% by mass, MgO 0.5 to 20% by mass, CaO 3 to 35% by mass, MgO + CaO 19 to 40% by mass, SiO ₂ 64.7 to 80 _{wt%, Al} 2 O 3 0.3 to 3 wt%, MgO 4 to 20 wt%, CaO 3 to 30% by weight, preferably MgO + CaO 19-35 wt%, _SiO 2 74 ~ 80 _wt%, Al ₂ O 3 1 to 3 wt%, MgO16～20 mass%, CaO 3 to 5 wt%, more preferably MgO + CaO 19 to 25 wt%.

  The average fiber diameter of such inorganic fibers is not particularly limited as long as the inorganic fibrous molded body can be suitably produced, but is 1 to 50 μm, preferably 1.5 to 10 μm, and particularly preferably 2 to 6 μm. If the average fiber diameter is less than 1 μm, the fibers are likely to break, so the strength of the inorganic fibrous molded body tends to be low. If the average fiber diameter exceeds 50 μm, the density of the inorganic fibrous molded body is low. The strength of the molded body tends to be low. In addition, the average fiber length of the biosoluble inorganic fiber is not particularly limited as long as the inorganic fibrous molded body can be suitably manufactured, but is 1 to 200 mm, preferably 2 to 50 mm, and particularly preferably 10 to 50 mm. When the average fiber length is within the above range, an inorganic fibrous molded body having an appropriate density can be easily obtained.

  In the inorganic fibrous molded body of the present invention, the content of inorganic fibers is 50 to 98% by mass, preferably 70 to 98% by mass, and particularly preferably 90 to 98% by mass.

  In the present invention, the binder may be either an inorganic binder or an organic binder, or a combination of an inorganic binder and an organic binder. The inorganic binder is not particularly limited, and examples thereof include colloidal silica such as anionic colloidal silica and cationic colloidal silica, fumed silica, zirconia sol, titania sol, alumina sol, bentonite, and kaolin. Is not particularly limited, and examples thereof include acrylic resin, starch, polyacrylamide and the like. An acrylic resin is preferable as the binder used for the inorganic fiber molded body having high followability to the shape of the wall surface during construction, that is, the soft inorganic fiber molded body. Moreover, as a binder used for an inorganic fiber molded object or a hard inorganic fiber molded object with high use temperature, the combination of an inorganic binder and starch or polyacrylamide is preferable. Polyacrylamide is preferred in that it acts as a flocculant during dehydration molding.

  In the inorganic fibrous molded body of the present invention, the content of the inorganic binder is 0.05 to 20% by mass, preferably 2 to 15% by mass, and particularly preferably 3 to 10% by mass. When the content of the inorganic binder is less than 0.05% by mass, it is difficult to obtain the effect of improving the strength of the inorganic fiber molded body by use in an industrial furnace or the like. The drainage of the water becomes poor and the production efficiency tends to deteriorate.

  The content of the organic binder is 0.05 to 15% by mass, preferably 0.1 to 10% by mass, particularly preferably 0.5 to 5% by mass. If the content of the organic binder is less than 0.05% by mass, the strength of the inorganic fibrous molded body after molding and drying tends to be low, and if it exceeds 15% by mass, combustion gas is often discharged from the inorganic fibrous molded body Become. In addition, the total content of the inorganic binder and the organic binder is 1 to 20% by mass, preferably 3 to 18% by mass, and particularly preferably 5 to 15% by mass.

  In the present invention, in addition to the reactive inorganic powder described above, for example, refractory inorganic powder such as ceramic powder such as silica, alumina, titania, zirconia, silicon nitride, silicon carbide, carbon powder such as carbon black, etc. is arbitrarily added. It may be added. By containing such a heat-resistant inorganic powder, the fire resistance of the inorganic fibrous molded body can be increased.

  The inorganic fibrous molded body of the present invention is before heating or firing, and can be used as a heat insulating material in an environment exceeding 1000 ° C. such as a heat treatment apparatus, an industrial kiln furnace, or an incinerator. That is, the inorganic fibrous molded body of the present invention is installed as a heat insulating material in a heat treatment apparatus, an industrial kiln furnace or an incinerator, and when heated at a temperature exceeding 1000 ° C. at the installation location, the inorganic fibrous molded body Although the inorganic fibers contained in the resin shrink, the reactive inorganic powders react with each other to expand due to heating. Therefore, the shrinkage and the expansion are offset, and the heat shrinkage generated in the inorganic fiber molded body can be reduced.

  The inorganic fibrous fired body of the present invention is obtained by firing the inorganic fibrous formed body, and the two or more types of reactive inorganic powders react with each other to expand in volume. The firing temperature is preferably 800 to 1100 ° C. The organic binder disappears by firing, and the inorganic fibers contained in the inorganic fiber molded body shrink. However, even if the inorganic fibers shrink, the reactive inorganic powders react with each other and expand due to heating, so that the shrinkage and the expansion are offset and the heat shrinkage that occurs in the inorganic fiber molded body can be reduced. Thus, the dimensions of the inorganic fiber molded body and the inorganic fiber fired body are almost the same, so that it is easy to design and manufacture.

Moreover, the inorganic fibrous fired body of the present invention comprises an inorganic fiber, an inorganic binder, Ca ₃ ZrSii ₂ O ₉ , CaZrO ₃ , CaTiO ₃ , (CaO) ₁₂ (Al ₂ O ₃ ) ₇ , Mg ₂ SiO ₄ and And one or more inorganic powders selected from MgTi ₂ O ₅ . Such an inorganic powder is a reaction product of the first reactive inorganic powder and the second reactive inorganic powder as shown in Table 1.

  The inorganic fiber fired body of the present invention may be used as a heat insulating material after being fired in a manufacturing factory, and the inorganic fiber molded body is installed as a heat insulating material in a heat treatment apparatus, an industrial kiln furnace or an incinerator. Thereafter, it may be fired in situ.

  The amorphous inorganic fibrous composition of the present invention contains inorganic fibers, a binder, a reactive inorganic powder, and a solvent, and the reactive inorganic powder comprises at least two types, and these reactivities. The inorganic powder has the property of reacting by firing to expand in volume. In the amorphous inorganic fibrous composition of the present invention, the same constituent elements as those of the inorganic fibrous molded body will be mainly described with respect to different points while omitting the description thereof. That is, in the amorphous inorganic fibrous composition of the present invention, the difference from the inorganic fibrous molded body is that it contains a solvent and the shape obtained is irregular.

  The solvent is not particularly limited, and examples thereof include water and polar organic solvents. Examples of the polar organic solvent include monovalent alcohols such as ethanol and propanol, and divalent alcohols such as ethylene glycol. Among these, water is preferable in that there is no deterioration of the working environment and there is no burden on the environment. Moreover, it does not restrict | limit especially as this water, Distilled water, ion-exchange water, tap water, groundwater, industrial water etc. are mentioned.

  An indeterminate shape includes a paste shape. The pasty viscosity, that is, the solid content concentration in the solvent is appropriately determined in consideration of the purpose of use and workability. The amorphous inorganic fiber composition of the present invention is used as a joint of an inorganic fiber molded body installed in, for example, a heat treatment apparatus, an industrial kiln furnace or an incinerator, and is heated to a temperature of 800 to 1100 ° C. In addition, even if the inorganic fiber contained in the amorphous inorganic fiber composition shrinks, the reactive inorganic powders react with each other and expand due to heating even when the inorganic fibers contained in the amorphous inorganic fiber composition shrink. The expansion is offset and the heat shrinkage that occurs in the amorphous inorganic fibrous composition can be reduced. For this reason, the joint crack after a heating can be suppressed. That is, the amorphous inorganic fiber fired body of the present invention is usually formed by heating at the construction site of the amorphous inorganic fiber composition.

  The content of the solvent is 50 to 800% by mass, preferably 100 to 800% by mass, particularly preferably 100 to 500% by mass with respect to 100% by mass of the solid in the amorphous inorganic fibrous composition according to the present invention. It is. When the content is less than 50% by mass, the fluidity of the amorphous inorganic fibrous composition is lowered, so that the workability is deteriorated, and the mechanical strength of joints, particularly the bending strength is lowered. Moreover, since the consistency of an amorphous inorganic fibrous composition will become high when this content exceeds 800 mass%, this composition will be dripped at the time of construction, and the shrinkage | contraction of the joint by drying will become large.

  The inorganic fiber is the same as that described in the description of the inorganic fiber molded body according to the present invention, and the content of the amorphous inorganic fiber composition according to the present invention in the solid content is 20 to 90% by mass. , Preferably 30 to 70% by mass, particularly preferably 40 to 60% by mass.

  The reactive inorganic powder is the same as that described in the description of the inorganic fiber molded body according to the present invention, and the content of the amorphous inorganic fiber composition according to the present invention in the solid content is 1 to 1. It is 49 mass%, preferably 1-30 mass%, particularly preferably 1-10 mass%.

  The binder is the same as that described in the description of the inorganic fiber molded body according to the present invention, and the content of the inorganic binder in the solid content of the amorphous inorganic fiber composition according to the present invention is the inorganic fiber. It is 20-200 mass% with respect to 100 mass%, Preferably it is 30-100 mass%, Most preferably, it is 40-80 mass%. Content of an organic binder is 0.05-15 mass% with respect to 100 mass% of said inorganic fiber, Preferably it is 0.1-10 mass%, Most preferably, it is 0.5-5 mass%.

  The amorphous inorganic fibrous composition of the present invention contains additives such as refractory inorganic powder, thickener, dispersant, preservative, etc., in addition to the inorganic fiber, reactive inorganic powder, binder and solvent. Can do.

  The refractory inorganic powder is the same as that described in the description of the inorganic fiber molded body according to the present invention, and the content of the refractory inorganic powder in the solid content of the amorphous inorganic fiber composition according to the present invention. Is preferably 1 to 150% by mass, particularly preferably 5 to 100% by mass with respect to 100% by mass of the inorganic fiber.

  The thickening material is not particularly limited, and known materials can be used. Specific examples include hydroxyethyl cellulose, sodium acrylate polymer, polyether polyol, and acrylic polymerized polymer polyesteramine. Although content in particular of this thickener is not restrict | limited, 2-15 mass% is preferable in solid content of the amorphous inorganic fiber composition which concerns on this invention.

  The dispersant is not particularly limited, and known ones can be used. Specific examples include carboxylic acids, polyhydric alcohols, amines and the like, and the content of the dispersant is not particularly limited, but 1 to 5 in the solid content of the amorphous inorganic fibrous composition according to the present invention. Mass% is preferred.

  The preservative is not particularly limited, and examples thereof include an inorganic compound or an organic compound having a nitrogen atom or a sulfur atom, and the content of the preservative is not particularly limited, but the amorphous inorganic fiber according to the present invention is not limited. 1-5 mass% is preferable in solid content of a quality composition.

  The method for producing an inorganic fiber molded body of the present invention includes a slurry production step for obtaining a slurry containing a solvent, inorganic fibers, reactive inorganic powder and a binder, and an inorganic material having a desired shape by dehydrating the solvent in the slurry. And a dehydration molding step for obtaining a fibrous molded body.

  The solvent used in the slurry production process is the same as that used in the amorphous inorganic fibrous composition.

  The slurry concentration is preferably 0.1 to 10% by mass, particularly preferably 0.3 to 8% by mass, and further preferably 0.5 to 3% by mass. If the slurry concentration is less than 0.1% by mass, the amount of water to be removed in the dehydration molding process becomes excessive, which is inefficient. If the slurry concentration exceeds 10% by mass, the solid content is uniformly dispersed in the slurry. It becomes difficult to do. In addition, in this invention, slurry concentration shows the mass ratio (mass%) of the solid content which occupies in this slurry.

  The inorganic fiber, the reactive inorganic powder, and the binder used in the slurry manufacturing process are the same as the inorganic fiber, the reactive inorganic powder, and the binder, respectively, in the inorganic fiber molded body of the present invention.

  Moreover, the mixing amount of the inorganic fiber, the reactive inorganic powder, and the binder in the slurry is an amount that is a blending amount related to the inorganic fibrous molded body after dehydration molding and drying. As a form of the binder which concerns on the manufacturing method of the inorganic fiber molded object of this invention, any may be sufficient as a solid substance, a suspension, or a solution, and it does not restrict | limit.

  The dehydration molding step is a step of dehydrating the solvent in the slurry and then drying to obtain an inorganic fibrous molded body having a desired product shape. In addition, in the manufacturing method of the inorganic fiber molded object of this invention, since water is often used as this solvent, the word of dehydration molding was used.

  The removal of the solvent in the slurry (when the solvent is water, dehydration of water) is performed, for example, by pouring the slurry into a mold having a net installed at the bottom, and the solvent (when the solvent is water). Is performed by sucking water).

  The dehydrate is then heated in a dryer and dried. The drying temperature during the drying is 40 to 180 ° C, preferably 60 to 150 ° C, particularly preferably 80 to 120 ° C.

  The method for producing an amorphous inorganic fibrous composition of the present invention includes an irregularly shaped product producing step for obtaining an irregularly shaped product containing a solvent, inorganic fibers, a reactive inorganic powder and a binder. In the method for producing an amorphous inorganic fiber composition of the present invention, the description of the same constituent elements as those of the method for producing an inorganic fiber molded body is omitted, and different points are mainly described. That is, in the method for producing an amorphous inorganic fibrous composition of the present invention, the difference from the method for producing an inorganic fibrous molded body is that an irregularly shaped product producing step is used instead of the slurry producing step, a dehydrating molding step It is in the point that is omitted. An example of the indefinite shape is a paste.

  As the process for producing an indefinite shape, a known method of mixing a mixed material such as inorganic fibers with a kneader can be applied. Although it does not restrict | limit especially as a temperature to mix, Preferably it is 5-40 degreeC, The time to mix is although it does not restrict | limit in particular, Preferably it is 0.1 to 1.0 hour.

  The paste concentration, that is, the mass ratio (mass%) of the solid content in the paste may be appropriately determined in consideration of the purpose of use and workability of the amorphous inorganic fibrous composition.

  EXAMPLES Next, although an Example is given and this invention is demonstrated more concretely, this is only an illustration and does not restrict | limit this invention.

(Production of slurry containing inorganic fibers)
First, 86.2% by mass of aluminosilicate fibers as inorganic fibers in water, 2.6% by mass of calcium carbonate as the first reactive inorganic powder, and 2.6% by mass of zirconium silicate as the second reactive inorganic powder. In addition, 4.7% by mass of colloidal silica as an inorganic binder, 2.2% by mass of starch and 1.7% by mass of a cationic paper strength enhancer are added as an organic binder, and water is added so that the slurry concentration becomes 3% by mass. And stirred to obtain a slurry. The following materials were used for each material.

Aluminosilicate fiber: “Fine Flex Bulk Fiber” (Nichias)
・ Calcium carbonate; (Shiraishi Calcium Co., Ltd.) Average particle size
・ Zirconium silicate; (manufactured by Kinsei Matec Co., Ltd.) average particle size 2 μm
Inorganic binder: 30% colloidal silica, “Silica Doll 30” (manufactured by Nippon Chemical Industry Co., Ltd.), suspension with a solid content of 30%, average particle size of solid content 15 nm, pH 10.0
・ Organic binder: Starch, “Petrosize J” (manufactured by Nissho Chemical Co., Ltd.)
Organic binder: cationic paper strength enhancer, “Polystron 311” (manufactured by Arakawa Chemical Industries, Ltd.), cationic, non-volatile content 10% by mass, pH 4.2 to 4.8, viscosity 500 to 1500 cps

(Confirmation of volume expansion property 1)
In addition, based on the laboratory confirmation test of the property of volume expansion, it was confirmed that calcium carbonate and zirconium silicate have the property of volume expansion upon reaction by heating. That is, calcium carbonate and zirconium silicate reacted by heating at 840 ° C. to generate Ca ₃ ZrSi ₂ O ₉ . The product was confirmed by XRD measurement. The volume of the Ca ₃ ZrSi ₂ O ₉ containing molded body was increased by about 15% from the total volume of calcium carbonate and zirconium silicate before heating.

(Suction filtration)
The slurry obtained as described above was dehydrated and dried at 110 ° C. to obtain an inorganic fibrous molded body (sample A0) having a density of 250 kg / m ³ .

(1) Heat shrinkage rate The inorganic fiber molded body obtained as described above was heated in an electric furnace at 1100 ° C. for 8 hours, and the length of the heated inorganic fiber molded body (sample A1) was measured. To do. The heating line shrinkage rate is obtained by the following equation, where Xmm is the length of the inorganic fiber molded body before heating, and Ymm is the length after heating. The results are shown in Table 2.
Heating linear shrinkage rate (%) = {(XY) / X} × 100

(2) Bending strength The bending strength of Samples A0 and A1 was calculated using the following equation by applying a load at a head speed of 10 mm / min using a three-point bending strength tester and measuring the breaking load. The results are shown in Table 2.
Bending strength (MPa) = {3 × maximum load (N) × distance between lower fulcrums (mm)} / {2 × width of inorganic fiber molded body (mm) × (thickness of inorganic fiber molded body (mm) ² }

(Examples 2-11, Comparative Examples 1-2)
The same procedure as in Example 1 was performed except that the amount of inorganic powder mixed was changed to the amounts shown in Tables 2 to 4. The results are shown in Tables 2-4. Comparative Examples 1 and 3 are examples in which unexpanded vermiculite was used as the reactive inorganic powder, and Comparative Examples 2 and 4 were examples in which no inorganic powder was used. Comparative Example 2 is also shown in Table 3 for easy comparison. The following materials were used.
Biosoluble inorganic fibers: SiO ₂ 74 to 80% by mass, CaO + MgO 19 to 25% by mass, Al ₂ O ₃ 1 to 3% by mass, average fiber diameter 4 μm, average fiber length 5.0 mm, physiological saline at 40 ° C. Dissolution rate 5.9%
・ Aluminum hydroxide: (Showa Denko) average particle size 10μm
Zirconium oxide: (Made by Showa Denko) Average particle size 10 μm
・ Titanium oxide: (Taika) average primary particle size 50nm
・ Unexpanded vermiculite: (from South Africa) average particle size 5mm

(Confirmation of volume expansion property 2)
In addition, based on the laboratory confirmation test of the property of volume expansion, it was confirmed that calcium carbonate and aluminum hydroxide have a property of volume expansion by reacting with heating. That is, calcium carbonate and aluminum hydroxide reacted by heating at 1030 ° C. to produce (CaO) ₁₂ (Al ₂ O ₃ ) ₇ . The product was confirmed by XRD measurement. The volume of the (CaO) ₁₂ (Al ₂ O ₃ ) ₇ -containing molded body was increased by about 12% from the total volume of calcium carbonate and aluminum hydroxide before heating.

(Confirmation of volume expansion property 3)
In addition, based on the laboratory confirmation test of the volume expansion property, it was confirmed that calcium carbonate and zirconium oxide have a property of volume expansion upon reaction by heating. That is, calcium carbonate and zirconium oxide reacted with each other by heating at 980 ° C. to produce CaZrO ₃ . The product was confirmed by XRD measurement. The volume of the CaZrO ₃ -containing molded body was increased by about 15% from the total volume of calcium carbonate and zirconium oxide before heating.

(Confirmation of volume expansion property 4)
In addition, based on the laboratory confirmation test of the property of volume expansion, it was confirmed that calcium carbonate and titanium oxide have a property of volume expansion upon reaction by heating. That is, calcium carbonate and titanium oxide reacted with heating at 800 ° C. to produce CaTiO ₃ . The product was confirmed by XRD measurement. The volume of the CaTiO ₃ -containing molded body was increased by about 3% from the total volume of calcium carbonate and titanium oxide before heating.

  As shown in Tables 2 to 4, even when the inorganic fiber molded body and the inorganic fiber fired body of Examples 1 to 11 are used as heat insulating materials in an environment exceeding 1000 ° C., they are heated or fired. It was found that the dimensional shrinkage was small, and that it had sufficient mechanical strength for practical use.

Claims (5)

Inorganic fiber molded body containing 50 to 98% by mass of inorganic fibers made of silica-alumina based biosoluble fiber containing CaO and MgO , 1 to 20% by mass of binder, and 1 to 30% by mass of reactive inorganic powder. Because
The reactive inorganic powder is at least one or more first reactive inorganic powders selected from calcium carbonate and magnesium carbonate, and one or more first reactive inorganic powders selected from zirconium silicate, zirconium oxide, titanium oxide and aluminum hydroxide. 2 reactive inorganic powders,
These reactive inorganic powders have the property of reacting by firing to expand in volume, and are characterized in that they are inorganic fiber molded bodies. The firing temperature is, the inorganic fibrous molded body according to claim 1, wherein it is 800 to 1100 ° C.. An inorganic fibrous material obtained by firing the inorganic fibrous molded body according to claim 1 or 2 , wherein the reactive inorganic powder reacts and expands in volume. Fired body. In terms of solid content, it contains 50 to 98% by mass of inorganic fiber made of silica-alumina-based biosoluble fiber containing CaO and MgO , 1 to 20% by mass of binder, and 1 to 30% by mass of reactive inorganic powder. together, it is amorphous inorganic fibrous composition comprising solvent,
The reactive inorganic powder is at least one or more first reactive inorganic powders selected from calcium carbonate and magnesium carbonate, and one or more first reactive inorganic powders selected from zirconium silicate, zirconium oxide, titanium oxide and aluminum hydroxide. 2 reactive inorganic powders,
These reactive inorganic powders have the property of reacting by firing to expand in volume, thereby forming an amorphous inorganic fibrous composition. An amorphous inorganic fibrous material obtained by firing the amorphous inorganic fibrous composition according to claim 4 , wherein the reactive inorganic powder reacts and expands in volume. Fired body.