JP2006282404A - Monolithic heat insulating material composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monolithic heat insulating material composition which employs a biosoluble inorganic fiber and which is little in shrinkage by heating even after the lapse of storage period after production and exhibits an appropriate strength after being fired. and to provide a method for producing the same. <P>SOLUTION: The monolithic heat insulating material composition contains an inorganic fiber having a dissolution rate in a physiological saline solution at 40°C of ≥1%, a solvent, and a pH adjusting agent, and has a pH of 4-8.5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is, for example, a heat insulating apparatus, a joint material in an industrial furnace or an incinerator, in particular, an insulative heat insulating material used as a joint material for filling a gap between a refractory tile, a heat insulating brick, an iron skin, a mortar refractory, etc. The present invention relates to a composition and a method for producing the composition, and more specifically, relates to an amorphous heat insulating material composition including inorganic fibers having a physiological saline dissolution rate of 1% or more (hereinafter also referred to as biosoluble inorganic fibers).

  Conventionally, the amorphous heat insulating material composition includes glass fiber, glass wool, ceramic wool, rock wool, alumina fiber, zirconia fiber, silica / alumina fiber, etc. (hereinafter referred to as inorganic fiber of conventional amorphous heat insulating material composition, etc.) And as a reinforcing fiber. The amorphous heat insulating material composition is inserted into a gap such as a tile by glazing, spraying or pouring to form joints. At that time, the inorganic fibers and the like of the conventional amorphous heat insulating material composition contained in the amorphous heat insulating material composition are scattered as dust in the air, and the worker inhales the dust. When inorganic fibers of this conventional amorphous heat insulating material are inhaled by humans and enter the lungs, phagocytic alveolar macrophages (phagocytic cells) surround the foreign body and carry them to the place where cilia are located (trachea and bronchi). At the same time, it drains out of the body, and drains from the alveolar surface via lymph and lymphatic vessels. However, the alveolar macrophages may be stimulated or damaged due to the surrounding foreign material, and as a result, proteolytic enzymes and collagen fiber degrading enzymes are released from the cells, and if the amount of these enzymes increases, the alveolar cells May cause irritation or collagenation. These inflamed cells are less resistant, making it easier to damage the DNA in the cell's nucleus, and the frequent destruction and remanufacturing process, resulting in more opportunities for abnormal cells to appear. As a result, there is a concern that DNA cells may be altered and cancer cells may be induced. Therefore, development of an amorphous heat insulating material composition that does not use inorganic fibers of the conventional amorphous heat insulating material is desired. It was.

  Since the biosoluble inorganic fiber is dissolved in the body even if inhaled into the lung and does not accumulate in the lung, the biosoluble inorganic fiber is used as a reinforcing fiber in place of the inorganic fiber of the conventional amorphous heat insulating material composition. It is known to use fibers. However, the biologically soluble inorganic fiber is easily dissolved in a solvent such as water, and a part or most of it elutes into the solvent during preparation or storage of the amorphous heat insulating material composition. There was a problem that the strength of the joint formed by the object was lowered.

As a solution to this problem, Japanese Patent Publication No. 2002-524384 discloses a stucco containing an inorganic refractory fiber of an alkaline earth metal silicate and colloidal silica having a pH of less than 8, particularly 4 to 7. According to this plaster, since the supply of acidic colloidal silica reduces the liberation of calcium ions from the fibers, the inorganic fiber constituents in the plaster are not solidified, and the storage stability is excellent.
JP 2002-524384 A (Claim 1)

  However, the stucco described in JP-T-2002-524384 does not sufficiently inhibit the dissolution of fiber constituents, although the release of calcium ions is reduced during storage after manufacture, and the divisor after manufacture. There are problems such that the pH increases in a week and the heat shrinkage ratio increases, and the physical properties of the heat insulating material composition decrease. Moreover, when acidic colloidal silica is used, there is a problem that the shrinkage rate of the joint after the construction becomes large, a gap is formed in the joint, and the heat insulation and fire resistance are deteriorated.

  Accordingly, an object of the present invention is an amorphous heat insulating material composition using a biosoluble inorganic fiber, which has little heat shrinkage even after the storage period after production and has an appropriate strength after firing. An object is to provide an amorphous heat insulating material composition and a method for producing the same.

  Under such circumstances, the present inventors have conducted extensive studies, and as a result, (1) when the biosoluble inorganic fiber is dissolved in the solution, the pH becomes high and becomes alkaline. Decrease in strength, (2) If a pH adjuster is added to the amorphous heat insulating material composition, and the pH is kept at 4 to 8.5 immediately after production and during the storage period, dissolution of the fiber component is suppressed. It was found that, even after the storage period after production, the heat shrinkage is small, and after firing, an amorphous heat insulating material having an appropriate strength can be obtained, and the present invention has been completed.

  That is, this invention (1) is a composition containing a biosoluble inorganic fiber, a solvent, and a pH adjuster, and provides an amorphous heat insulating material composition having a pH of 4 to 8.5. To do.

  Moreover, this invention provides the manufacturing method of the amorphous heat insulating material composition which mixes biosoluble inorganic fiber, a solvent, and a pH adjuster, and obtains a composition with pH 4-8.5.

  The present invention also provides an organic fiber mixing step of mixing a solvent and an organic fiber, an inorganic fiber that mixes the solvent and the organic fiber, a biosoluble inorganic fiber, and a pH adjuster after the organic fiber mixing step. The manufacturing method of the amorphous heat insulating material composition which has a fiber mixing process is provided.

  According to the present invention, an amorphous heat insulating material composition using biologically soluble inorganic fibers, which has little heat shrinkage even after the storage period after production, and has a suitable strength after firing. An amorphous heat insulating material composition to be formed and a method for producing the same can be provided.

  First, the amorphous heat insulating material composition according to the present invention will be described. The amorphous heat insulating material composition contains biosoluble inorganic fibers, a solvent, and a pH adjuster.

  The biologically soluble inorganic fiber according to the present invention (hereinafter also simply referred to as inorganic fiber) has a physiological saline dissolution rate at 40 ° C. of 1% or more. If the physiological saline dissolution rate is less than 1%, it is difficult to dissolve in the living body even if inhaled into the lung, so that the inorganic fiber accumulates in the lung and causes various respiratory diseases. A method for measuring the physiological saline dissolution rate will be described. 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. Next, a horizontal vibration is applied to the Erlenmeyer flask at 120 rpm for 50 hours, followed by filtration and drying to obtain an insoluble matter. The weight of the obtained insoluble matter is measured, and the value is subtracted from the weight before dissolution to determine the weight reduction rate (% by weight) due to dissolution. Then, the weight reduction rate due to the dissolution is defined as a physiological saline dissolution rate.

Examples of the biosoluble inorganic fiber include inorganic fibers described in JP-A-2000-220037, JP-A-2002-68777, JP-A-2003-73926, or JP-A-2003-212596. Is mentioned. Specifically, the total content of SiO ₂ and CaO is 85% by mass or more, containing 0.5 to 3.0% by mass of MgO and 2.0 to 8.0% by mass of P ₂ O _5. Inorganic fibers having a carcinogenicity index (KI value) of 40 or more according to German hazardous substance regulations, inorganic fibers containing SiO ₂ , MgO and TiO ₂ as essential components, inorganic containing SiO ₂ , MgO and manganese oxide as essential components _fiber, SiO 2 fifty-two to seventy-two wt%, _Al less than 2 _{O 3} 3 wt%, MgO 0 to 7 wt%, CaO 7.5 to 9.5 _{wt%, B} 2 O 3 _0~12 wt%, BaO 0 to Inorganic fiber containing 4% by mass, SrO 0-3.5% by mass, Na ₂ O 10-20.5% by mass, K ₂ O 0.5-4.0% by mass and P ₂ O ₅ 0-5% by mass , _SiO 2 75-80 _{mass%, Al} 2 O 3 _1.0~3.0 mass , MgO 16 to 20 wt%, CaO 3.0 to 5.0 wt%, inorganic fibers containing _{K 2} O and / or _Fe 2 _O 3 0 to 2.0 wt%.

  The average fiber diameter of the biosoluble inorganic fiber is 1 to 50 μm, preferably 2 to 10 μm, and particularly preferably 2 to 5 μm. When the average fiber diameter is less than 1 μm, the strength of the joint becomes low. When the average fiber diameter exceeds 50 μm, when the organic fiber is used, it is difficult to be taken into the network of the organic fiber. The average fiber length of the inorganic fibers is 1 to 200 mm, preferably 2 to 50 mm, particularly preferably 10 to 50 mm. When the average fiber length is less than 1 mm, the strength of the joint becomes low, and when it exceeds 200 mm, the inorganic fibers are difficult to uniformly disperse in the solvent.

  Although it does not restrict | limit especially as a solvent based on this invention, Water and a polar organic solvent are mentioned, As this polar organic solvent, monovalent alcohols, such as ethanol and propanol, Divalent alcohols, such as ethylene glycol, are mentioned. Can be mentioned. 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, industrial water etc. are mentioned.

  The content of the solvent is 5 to 80 parts by mass, preferably 10 to 80 parts by mass, and particularly preferably 10 to 50 parts by mass with respect to 100 parts by mass of the solid in the amorphous heat insulating material composition according to the present invention. Part. When the content is less than 5 parts by mass, the fluidity of the amorphous heat insulating material 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 heat insulating material composition will become high when this content exceeds 80 mass parts, this composition will be dripped at the time of construction, and the shrinkage | contraction of the joint by drying will become large.

  Although it does not restrict | limit especially as a pH adjuster which concerns on this invention, For example, a buffer solution or an acid is mentioned, Among these, a buffer solution makes pH of an amorphous heat insulating material composition 4-8 over several months after manufacture. .5 is preferable in that it can be stably maintained and does not give off an irritating odor. A buffer solution generally refers to a solution that acts to mitigate the effect of external changes. This buffering action is usually said to the change in the hydrogen ion concentration of the solution. Specifically, the solution maintains an almost constant hydrogen ion concentration despite the addition or disappearance of some acid or base. Says the action. Examples of the buffer solution used in the present invention include a phthalate standard solution (Selensen buffer solution) which is a pH 4 standard solution and a neutral phosphate standard solution which is a pH 7 standard solution. It is preferable in that it disappears by firing and does not adversely affect the physical properties of the heat insulating material.

  The content of the buffer solution is not particularly limited as long as the pH of the amorphous heat insulating material composition is adjusted to 4 to 8.5, but specifically, it is 10 to 100 parts by mass of the inorganic fiber. -1000 mass parts, Preferably it is 50-500 mass parts. When the content of the buffer solution is too small, a predetermined pH value cannot be maintained, for example, during a storage period of 90 days after the production of the amorphous heat insulating material composition, and dissolution of the fiber component cannot be suppressed. Further, if the content of the buffer solution is too large, not only is it wasted, but salts such as potassium are contained, which is not preferable.

  Examples of the acid include acetic acid, formic acid and the like. Among these, acetic acid is preferable because it has a high pH lowering effect and is readily available. The acid content is not particularly limited as long as the pH of the amorphous heat insulating material composition is 4 to 8.5, but specifically, if the acetic acid solution is 99%, the inorganic fiber is 100 masses. 1 to 7 parts by mass, preferably 2 to 4 parts by mass with respect to parts. If the content of the acetic acid solution is too small, the pH cannot be maintained at 8.5 or lower during the storage period of, for example, 90 days after the production of the amorphous heat insulating material composition, and dissolution of the fiber component can be suppressed. Disappear. Further, if the content of the acetic acid solution is too much, it is not preferable because it is not only wasteful but also gives off a strange odor.

  When the amorphous heat insulating material composition of the present invention further contains an organic fiber, it is preferable in that the organic fiber acts as a protective film for the biosoluble inorganic fiber. The organic fiber is not particularly limited, and may be any of natural fiber or hydrophobic treated synthetic fiber. Examples of the natural fiber include pulp, cotton, hemp and the like. , Rayon, polypropylene, polyethylene and the like. Of these, pulp is preferable because it easily incorporates the inorganic fibers. In addition, a pulp refers to what isolate | separated the fiber of the plant body by the mechanical or chemical process. Both organic and inorganic fibers have a certain degree of hydrophobicity, and when organic and inorganic fibers are put into water, they will float for a certain period of time without drowning rapidly. It is preferable in terms of improving the mixing property with the material. The hydrophobic treatment refers to a treatment for improving the hydrophobicity of the fiber. Examples of the hydrophobic treatment method include a method of coating the periphery of the fiber with a hydrophobic drug.

  When the inorganic fiber is present, the organic fiber takes the inorganic fiber into the network of the organic fiber. Thereby, the organic fiber covers the periphery of the inorganic fiber and serves as a protective layer that prevents the inorganic fiber from coming into contact with the solvent. That is, the organic fiber network near the surface that is in contact with the solvent takes in the solvent, so that the organic fiber is in direct contact with the inorganic fibers that are taken into the organic fiber network. To prevent. Therefore, since it can prevent that this inorganic fiber elutes in a solvent and takes in a solvent in a crystal | crystallization, it prevents that the shrinkage rate of the joint after implementation becomes large, for example. Moreover, since the inorganic fibers are fixed to each other via the organic fibers, the organic fibers function as a reinforcing material for the inorganic fibers.

  The organic fiber is not particularly limited, but preferably has a freeness of 200 to 500 ml. The freeness is a value obtained by the “pulp freeness test method” defined in JIS P 8121-1995, and is an index of water retention. The lower the freeness, the higher the water retention. The organic fibers having a freeness of 200 to 500 ml have a high affinity with the inorganic fibers, so that the inorganic fibers can be easily taken in and have appropriate water retention. Highly effective in preventing direct contact. If the freeness is less than 200 ml, the organic fibers absorb too much moisture, making it difficult to incorporate inorganic fibers. If the freeness exceeds 500 ml, the affinity with the inorganic fibers is low, so the inorganic fibers are incorporated. It becomes difficult.

  The average fiber diameter of the organic fiber is 1 to 30 μm, preferably 2 to 10 μm, and particularly preferably 2 to 5 μm. When the average fiber diameter is less than 1 μm, the strength of the joint becomes low, and when it exceeds 30 μm, it becomes difficult to incorporate the inorganic fibers. And it is preferable that the average fiber diameter of this organic fiber shall be below the average fiber diameter of the said inorganic fiber at the point which this organic fiber takes in this inorganic fiber easily. The average fiber length of the organic fiber is 0.5 to 20 mm, preferably 1 to 10 mm, particularly preferably 2 to 5 mm. When the average fiber length is less than 0.5 mm, the strength of the joint becomes low, and when it exceeds 20 mm, the organic fiber is difficult to be uniformly dispersed in the solvent.

  Content of this organic fiber is 5-50 mass parts with respect to 100 mass parts of said inorganic fibers, Preferably it is 10-30 mass parts, Most preferably, it is 15-25 mass parts. When the content of the organic fiber is less than 5 parts by mass, the effect of suppressing the elution of the inorganic fiber is reduced, and when it exceeds 50 parts by mass, the strength of the joint is reduced.

  The amorphous heat insulating material composition according to the present invention further includes a heat-resistant powder, thereby increasing the fire resistance. Examples of the heat-resistant powder include ceramic powder such as silica, alumina, silicon nitride and silicon carbide, metal powder such as magnesium, carbon powder such as carbon black, Teflon (registered trademark) resin, heat-resistant vinyl chloride resin and the like. Resin powders and the like are mentioned. Among these, ceramic powders such as silica, alumina, silicon nitride, and silicon carbonate, and carbon powders such as carbon black are preferable, and silica, alumina, silicon nitride, silicon carbonate, and the like are particularly preferable. Ceramic powder. The heat-resistant powder can be added after the heat-resistant powder is colloidally dispersed in a solvent. Examples of the colloidal heat-resistant powder dispersed in a solvent include colloidal silica. The colloidal silica preferably has a pH of 7 or more. The amorphous heat insulating material composition blended with acidic colloidal silica is not preferable because it causes gelation and is difficult to pump.

  The average particle diameter of the heat resistant powder is 0.1 to 100 μm, preferably 0.2 to 50 μm, and particularly preferably 0.2 to 10 μm. When the average particle diameter is less than 0.1 μm, the heat-resistant powder is easily removed from the gap between the inorganic fiber or the inorganic fiber and the organic fiber, and the heat-resistant powder is easily separated. On the other hand, when the average particle diameter exceeds 100 μm, it is difficult to be taken into the inorganic fiber or the organic fiber, and the heat-resistant powder is difficult to uniformly disperse.

  Content of this heat resistant powder is 10-300 mass parts with respect to 100 mass parts of said inorganic fibers, Preferably it is 20-200 mass parts, Most preferably, it is 40-150 mass parts. If the content is less than 10 parts by mass, the fire resistance will be low, and if it exceeds 300 parts by mass, the adhesion of the joints to the adherend will be low.

  In addition, the amorphous heat insulating material composition according to the present invention includes additives such as a binder, a thickener, a dispersant, and a preservative in addition to the biosoluble inorganic fiber, the pH adjuster, the organic fiber, and the heat resistant powder. Can be included.

  The binder is not particularly limited as long as it is generally used as a binder for an amorphous heat insulating material composition. For example, colloidal silica, alumina sol obtained by dissolving alumina powder in water, aluminum phosphate An aqueous solution etc. are mentioned. Of these, colloidal silica, alumina powder, and the like are preferable in that they are inexpensive. The content of the binder is not particularly limited, but is preferably 50 to 200 parts by mass with respect to 100 parts 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 parts is preferable with respect to 100 mass parts of said inorganic fibers.

  The dispersant is not particularly limited, and known ones can be used. Specific examples include carboxylic acids, polyhydric alcohols, amines, and the like. The content of the dispersant is not particularly limited, but is preferably 1 to 5 parts by mass with respect to 100 parts by mass of the inorganic fibers.

  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. 1-5 mass parts is preferable with respect to it.

  The amorphous heat insulating material composition according to the present invention has a pH of 4 to 8, preferably 4 to 6, both immediately after production and after storage for at least one month. The storage condition for at least one month is a storage method in a closed container at room temperature in a dark place. The amorphous heat insulating material composition preferably has a pH of 4 to 8.5, preferably 4 to 7 even when stored for 3 months under the same storage conditions. With such an amorphous heat insulating material composition, the constituent components of the biosoluble inorganic fiber are not dissolved even during long-term storage, and the same excellent characteristics as those immediately after production are exhibited. A conventional amorphous heat insulating material composition does not contain a pH adjuster, and even if there is a pH within 8 immediately after production, highly reactive biosoluble inorganic fibers are gradually added during the storage period. It dissolves in the solution and the strength of the joint formed by the amorphous heat insulating material composition is lowered. The amorphous heat insulating material composition according to the present invention may be adjusted in pH by adding a pH adjuster during the storage period immediately after production. In the amorphous heat insulating material composition according to the present invention, if the pH is less than 4, there is a problem in handling, and it is not preferable in terms of corroding the metal, and the pH exceeds 8.5. Elution of biosoluble inorganic fibers is likely to occur.

  Further, when the amorphous heat insulating material composition contains organic fibers, the organic fibers serve as a protective layer for the biosoluble inorganic fibers and also serve as a reinforcing material for the inorganic fibers. It is possible to further prevent the performance of the heat insulating material formed by the amorphous heat insulating material composition from being deteriorated by elution into the water or tearing during kneading. Moreover, the amorphous heat insulating material composition in which the organic fiber is blended is less likely to further deteriorate the performance of the heat insulating material even after long-term storage.

  Next, the manufacturing method of the amorphous heat insulating material composition which concerns on this invention is demonstrated. In the production method, the mixing order of the respective raw materials is not particularly limited, but a method of obtaining a composition having a pH of 4 to 8.5 by mixing biosoluble inorganic fibers, a solvent and a pH adjuster (simultaneous mixing method). ) Is preferred. Specifically, a known method of mixing biosoluble inorganic fibers, a solvent, and a pH adjuster 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.

  When organic fibers are included, an organic fiber mixing step of mixing a solvent and organic fibers, a mixture containing the solvent and the organic fibers, a biosoluble inorganic fiber, and a pH adjuster after the organic fiber mixing step. A method having an inorganic fiber mixing step of mixing is preferable.

  The amount of the solvent to be mixed in the organic fiber mixing step may be the whole or a part of the amount of the solvent necessary for the amorphous heat insulating material composition produced by the production method according to the present invention. However, the amount of the solvent mixed in the organic fiber mixing step is 30 to 50% by mass of the amount of the solvent necessary for the amorphous heat insulating material composition, so that the solid matter in the amorphous heat insulating material composition However, it is preferable in that it can be easily dispersed uniformly. In addition, when the solvent mixed in the organic fiber mixing step is a part of the amount of the solvent necessary for the amorphous heat insulating material composition, the remainder is mixed once or twice or more in the subsequent step. can do.

  The type, freeness, average fiber diameter, and average fiber length of the organic fiber mixed in the organic fiber mixing step are the same as those of the organic fiber described in the description of the amorphous heat insulating material composition according to the present invention. The organic fiber that has been opened is preferable in that it can be easily dispersed in the solvent and can easily incorporate the inorganic fiber.

  The opening of the organic fiber can be performed using, for example, an apparatus called a pulper. The pulper is a device that is commonly used in the manufacture of paper to open organic fibers that have been crushed and loosened in an organic fiber sheet. And, when the organic fiber is opened by the pulper or the like, a part of the surface of the main chain of the organic fiber is torn short, so that the organic fiber has a shape having many short side chains branched from the main chain of the fiber. It becomes. At this time, the side chain (branch) generated by tearing from the main chain is finely wavy (fibrillation). In this way, the cut organic fiber has a side chain with a finely undulating shape, so that the inorganic fiber can be easily taken into the network of the organic fiber. Thus, when the inorganic fibers are mixed, the inorganic fibers are quickly taken up, and the side chains are easy to take up the solvent, so that they are easily dispersed in the solvent, and when mixed with the solvent, they spread uniformly throughout the solvent. Therefore, the cut organic fibers can reduce the contact of the inorganic fibers with the solvent when the inorganic fibers are mixed in the inorganic fiber mixing step described later. Confirmation that the organic fibers are opened can be performed, for example, by measuring the freeness, and the open organic fibers have a freeness of 200 ml or more.

  Then, the solvent and the organic fiber are mixed using a conventional means such as a kneader. The mixing temperature and time can be performed under the same conditions as described in the simultaneous mixing method.

  In the inorganic fiber mixing step, the physiological fiber dissolution rate, type, average fiber diameter and average fiber length, and pH adjuster of the inorganic fiber are described in the description of the amorphous heat insulating material composition according to the present invention. It is the same as that of an inorganic fiber and a pH adjuster, and the mixing means, the temperature and time to mix are the same as the said simultaneous mixing method.

  Also, after the organic fiber mixing step and before the inorganic fiber mixing step, the mixture containing the solvent and the organic fiber, or after the inorganic fiber mixing step, the mixture containing the solvent, the organic fiber and the inorganic fiber, Additives such as a conductive powder, a binder, a thickener, a dispersant, or a preservative can be mixed. Moreover, it is preferable that the heat-resistant powder is a dispersion previously dispersed in the solvent, and the dispersion is mixed with the mixture from the viewpoint that the heat-resistant powder can be uniformly dispersed in the amorphous heat insulating material composition.

  In the method for producing an amorphous heat insulating material composition according to the present invention, the amount of the inorganic fiber, solvent, pH adjuster, organic fiber, heat resistant powder, binder, thickener, dispersant and preservative Is the same amount as the content of each component described in the description of the amorphous heat insulating material composition according to the present invention.

  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.

<Manufacture of amorphous heat insulating material composition>
A 300 L container is prepared, and the biosoluble inorganic fiber, alumina powder, 30% colloidal silica suspension, thickener, preservative, pulp, inorganic binder, dispersant and pH adjuster are shown in Table 1. It was added at a blending ratio. Then, it stirred for 30 minutes and obtained 2 kg of amorphous heat insulating material compositions. During stirring, the temperature of the mixture was 10-30 ° C.

  The physical property measurement of the obtained amorphous heat insulating material composition and the physical property measurement and performance evaluation of the heat insulating material formed by the amorphous heat insulating material composition were performed as follows. The results are shown in Table 1.

<Measurement of physical properties of amorphous heat insulating material composition>
(1) Consistency According to JIS K 2220, use a consistency meter. A metal cup having an inner diameter of 100 mm and an inner height of 50 mm is used, and a cone A is used for the cone.
(2) pH
Measurement was performed by immersing a pH test paper in the amorphous heat insulating material composition.

<Measurement of physical properties and evaluation of thermal insulation>
(Formation of insulation)
The amorphous heat insulating material composition is formed into a length of 160 × width of 40 × height of 40 mm in accordance with JIS R 2553 and heat-dried at 100 ° C. for 24 hours to obtain a heat insulating material.

(Measurement of physical properties of insulation)
(1) Density Calculated by measuring dimensional volume and mass according to JIS A 1116 (performance evaluation of heat insulating material)
(1) Heat shrinkage The heat insulating material obtained by heating and drying at 100 ° C. is heated in an electric furnace at 1100 ° C. for 24 hours, and the length of the heat insulating material after heating is measured. The heat shrinkage rate is obtained by the following equation, where the length of the heat insulating material before heating is X mm and the length after heating is Y mm.
Heat shrinkage rate (%) = {(XY) / X} × 100

(2) Bending strength after heating at 1100 ° C. The heat insulating material obtained by heating and drying at 100 ° C. is heated at 1100 ° C. for 24 hours to determine the bending strength of the heat insulating material after heating. The bending strength is measured according to JIS R 2553 by applying a load at a uniform speed of 49.03 to 68.05 N / sec using a three-point bending strength tester (Tensilon) and measuring the breaking load. Calculate by the formula.
Bending strength (MPa) = {3 × maximum load (N) × center distance of support roll (mm)} / {2 × heat insulation width (mm) × (heat insulation thickness (mm)) ² }

<Long-term storage test of amorphous heat insulating material composition>
Four 100 L containers were prepared, 100 g of amorphous heat insulating material composition A was put in each of the containers, the lid of the container was closed, and the container was further sealed with a sealing tape. The container containing the amorphous heat insulating material composition A was stored in a dark room at 25 ± 4 ° C. for 7 days, 30 days, 60 days, and 90 days, respectively. After elapse of a predetermined storage period, the amorphous heat insulating material composition is taken out of the container, the consistency and pH of the amorphous heat insulating material composition, and the heat insulating material obtained by heating and drying the amorphous heat insulating material composition at 100 ° C. The density, the heat shrinkage rate, and the bending strength after heating at 1100 ° C. were determined by the same method as described above. In addition, about the heat shrinkage rate of a heat insulating material and the bending strength after 1100 degreeC heating, the measurement after a 7-day preservation | save was abbreviate | omitted. The results are shown in Table 2.

Examples 2 to 6 and Comparative Examples 1 to 3
<Manufacture of amorphous heat insulating material composition>
Except that the blending ratio of each additive was the blending amount shown in Table 1, it was carried out in the same manner as in Example 1 to obtain 2 kg of an amorphous heat insulating material composition. The results are shown in Tables 1 and 2.

In addition, each raw material used for manufacture of an amorphous heat insulating material composition is as follows.
Biosoluble inorganic fiber; composition: SiO ₂ 78 mass%, CaO 0.15 mass%, MgO 19 mass%, average fiber diameter 4.5 μm, average fiber length 5.0 mm, physiological saline dissolution rate at 40 ° C. 5.9 %
Alumina powder (heat resistant powder); “A-32” (manufactured by Nippon Light Metal Co., Ltd.), average particle size 1 μm
Colloidal silica A: “Snowtech 30” (manufactured by Nissan Chemical Industries, Ltd.), 30% solid content (heat resistant powder) suspension, average particle size of solid content 15 μm, pH 8.0
Colloidal silica B; “Snow Tech 0” (manufactured by Nissan Chemical Industries, Ltd.), 30% solids (heat resistant powder) suspension, average particle size of solids 15 μm, pH 4.0
・ Thickener: Hydroxyethyl cellulose, “Heck Unicel QP52000H” (manufactured by Dow Chemical Company)
・ Sulfur-containing preservative: “Dell Top 512” (manufactured by Takeda Pharmaceutical Company Limited)
・ Pulp; “HARMAC R” (manufactured by Hermac Co.); average fiber diameter 5.5 μm, average fiber length 2.4 mm
・ Inorganic binder; “TA Kaolin” (manufactured by Sanyo Clay Industry Co., Ltd.)
・ Dispersant; “Primal 850FF” (Rohm and Haas)
・ Phthalate standard solution (pH 4 standard solution)
・ Neutral phosphate standard solution (pH7 standard solution)
・ Borate standard solution (pH 9 standard solution)
Acetic acid solution; 99% acetic acid solution

  In Table 2, after the storage period 30 days of Comparative Examples 1 and 2 and after the storage period 7 days of Comparative Example 3, the solid content and water are separated, the heat shrinkage rate is high, and the quality is greatly reduced. The physical properties and evaluation of the material composition were not performed.

  According to the present invention, there is provided an amorphous heat insulating material composition using biosoluble inorganic fibers, which has a small shrinkage and forms joints having appropriate strength, and a method for producing the same. Can do. Therefore, the work environment of the worker can be improved.

Claims (10)

  An amorphous heat insulating material composition comprising a biosoluble inorganic fiber, a solvent and a pH adjuster, wherein the composition has a pH of 4 to 8.5.   The amorphous heat insulating composition according to claim 1, wherein the biosoluble inorganic fiber is an inorganic fiber having a physiological saline dissolution rate at 40 ° C of 1% or more.   The amorphous heat insulating material composition according to claim 1 or 2, wherein the pH adjuster is a buffer solution or an acid.   Furthermore, organic fiber is contained, The amorphous heat insulating material composition of any one of Claims 1-3 characterized by the above-mentioned.   The amorphous heat insulating composition according to any one of claims 1 to 4, wherein the composition has a pH of 4 to 8.5 when stored at room temperature for at least one month after production.   The amorphous heat insulating composition according to any one of claims 1 to 5, wherein the solvent is included in an amount of 5 to 80 parts by mass with respect to 100 parts by mass of the solid in the amorphous heat insulating material composition. .   The amorphous heat insulating material composition according to claim 1, wherein the solvent is water.   A method for producing an amorphous heat insulating material composition comprising mixing a biosoluble inorganic fiber, a solvent, and a pH adjuster to obtain a composition having a pH of 4 to 8.5.   An organic fiber mixing step of mixing a solvent and an organic fiber, and an inorganic fiber mixing step of mixing the solvent and the organic fiber, a biosoluble inorganic fiber, and a pH adjuster after the organic fiber mixing step. The manufacturing method of the amorphous heat insulating material composition characterized by these.   The method for producing an amorphous heat insulating material composition according to claim 8 or 9, wherein the biologically soluble inorganic fiber is an inorganic fiber having a physiological saline solubility at 40 ° C of 1% or more.