JP2008105901A - Insulating material and method for producing the insulating material - Google Patents

Abstract

In a heat insulating material, when the heat insulating performance of the heat insulating material is improved and the strength is improved, the thickness of the heat insulating material can be further reduced and high heat is applied to the heat insulating material from the outside. Even when the temperature change per unit time (thermal shock) is large, the heat insulating material is prevented from being damaged such as cracks.
A heat insulating material includes an inorganic material, hollow fine particles, a reinforcing material, and a thermal deformation suppressing material. The inorganic material 2 is bentonite. The hollow fine particles 3 are made organic. The thermal deformation inhibitor 4 is at least one of talc and mica. The reinforcing material is inorganic fiber. The inorganic fiber has a laminated structure. The mass ratio of the inorganic material 2 / thermal deformation suppressing material 4 is 0.1-9.
[Selection] Figure 1

Description

  The present invention relates to a furnace wall of an electric heating furnace using induction heating (hereinafter referred to as an induction heating furnace), a heat insulating material used for heat insulation measures for equipment used in a high-heat atmosphere, and a method for manufacturing the heat insulating material. Is.

  The purpose of the furnace wall in the conventional induction heating furnace is to suppress radiant heat transfer from the object to be heated in the furnace to the heating coil and prevent the heating coil from being damaged by high heat. For this reason, although a heat insulating material is used for the said furnace wall, an electroconductive material cannot be used for the heat insulating material which comprises the furnace wall near this heating coil on the property of the said heating coil. For this reason, it was common to make the said heat insulating material with the inorganic fiber heat insulating material, fireproof heat insulating material (castable refractory), fireproof board, etc. which used the ceramic fiber etc. which are nonelectroconductive as a raw material.

  Conventionally, the following structure has been proposed as a structure for supporting the furnace wall. 1stly, in the case of a vertical induction heating furnace, there exists a structure which supports an inorganic fiber heat insulating material with a refractory support (patent document 1: Japanese Utility Model Publication No. 53-39686). Second, there is a structure in which the furnace wall is supported by the refractory heat insulating material itself (Patent Document 2: Japanese Patent Publication No. 53-9433). Third, in the case of a horizontal induction heating furnace, there is a structure in which the furnace wall is supported by a fireproof board or ceramics having a laminated structure whose strength is increased by reinforcing glass fibers or the like.

  In addition, as equipment used in a high-heat atmosphere, there are a molten metal level meter used in a continuous casting facility tundish, a flow rate measuring device for molten metal, and the like. Insulating materials such as ceramics and cahors are used as heat insulation measures for these devices.

  In addition, there is a heat insulating material used for a wall surface of a freezing room, a freezing container or the like (Patent Document 3: JP-A 2006-26977). Further, as the heat insulating material, there is an inorganic heat insulating material (insulating brick) such as an inorganic material or a porous material manufactured by firing an inorganic material (Patent Document 4: JP-A-6-263556).

  On the other hand, the inventors have developed a metal strip heating device (PTL 5: Japanese Patent Laid-Open No. 2003-187951) excellent in temperature uniformity in the plate width direction using induction heating, and molten metal using electromagnetic field technology. Development of a flow velocity measuring method and a flow velocity measuring device (Patent Document 6: Japanese Patent Laid-Open No. 2006-78352) have been performed.

  Among the above developments, the former development aims to make the heating coil more compact and more efficient, and therefore, the space between the upper and lower heating coils is a narrow interval of several tens of millimeters. In addition, since a steel plate heated to 700 ° C. or higher passes between the lower heating coils, a thin film heat insulating material for heating coil protection has been required.

  In the latter development, an eddy current method is used to measure the flow rate of molten metal in a slab under a mold of a continuous casting facility in a non-contact manner. In this case, although the slab surface temperature is very high (700-800 ° C.), the distance between the slab surface and the sensor for detecting the flow rate of the molten metal is narrowed to about several tens of mm. . For this reason, the thin film heat insulating material for sensor protection was required. It is difficult to increase the distance between the slab surface and the sensor for the following reason. That is, if the interval is increased, it is difficult to generate a magnetic field, and the flow rate of the molten metal cannot be measured. Further, when the interval is increased, the size of the sensor needs to be increased accordingly, so that the cost of the facility becomes expensive.

Japanese Utility Model Publication No. 53-39686 Japanese Patent Publication No.53-9433 JP 2006-26977 A JP-A-6-263556 JP 2003-187951 A JP 2006-78352 A

  Therefore, experiments were conducted using the above-described inorganic fiber heat insulating materials, fireproof boards, ceramic plates, castable refractories, etc., which are heat insulating materials of the prior art, and the following problems occurred.

  That is, the fiber heat insulating material has low strength. For this reason, when attaching this heat insulating material as a furnace wall, a refractory support | pillar is required like the conventional induction heating furnace. Therefore, it was difficult to attach the heat insulating material at a narrow interval because these support columns were in the way. The refractory board uses reinforcing glass fiber, so that the desired strength is ensured. However, since resin is used as the binder, the heat resistance is only about 350 ° C. Therefore, when this refractory board is used in a high heat atmosphere, the surface is easily carbonized, and a desired heat insulating effect cannot be obtained.

  The ceramic plate was vulnerable to a change in temperature per unit time (thermal shock), and immediately after the experiment was cracked and broken. The castable refractories and heat insulating bricks are excellent in heat resistance. However, since the thermal conductivity is large, when the thickness is small, the heat insulation performance is poor and it is difficult to protect the heating coil and sensor. Moreover, since the heat insulating board used for a freezer compartment etc. is organic and heat resistance is only about 350 degreeC, it cannot be used like the said fireproof board.

  The present invention has been made by paying attention to the above situation, and the object of the present invention is to improve the heat insulating performance of the heat insulating material and improve the strength, thereby reducing the thickness of the heat insulating material. In addition, in the case where high heat is given to the heat insulating material from the outside, even if the amount of temperature change per unit time in the heat insulating material is large, the heat insulating material should be free from defects such as cracks. .

  The invention of claim 1 contains an inorganic material 2, hollow fine particles 3, a reinforcing material, and a thermal deformation suppressing material 4.

  In addition to the invention of claim 1, the invention of claim 2 uses the inorganic material 2 as bentonite.

  In addition to the invention of claim 1, the invention of claim 3 makes the hollow fine particles 3 organic.

  According to a fourth aspect of the present invention, in addition to the first aspect of the invention, the thermal deformation suppressing material 4 is at least one of talc and mica.

  According to a fifth aspect of the present invention, in addition to the first aspect of the invention, the reinforcing material is an inorganic fiber.

  According to a sixth aspect of the invention, in addition to the fifth aspect of the invention, the inorganic fiber has a laminated structure.

  In addition to the invention of claim 1, the invention of claim 7 is such that the mass ratio of the inorganic material 2 / heat deformation suppressing material 4 is 0.1-9.

  In addition to the invention of claim 6, the invention of claim 8 has a structure in which the inorganic fiber has a structure of two or more layers, and the average particle diameter of the hollow fine particles 3 positioned outside the two inorganic fibers of the outermost layer is 40- The thickness is 5 μm.

  The heat insulating materials 9, 17, and 20 of the invention of claim 9 are formed by heating the heat insulating material 1 with the heat insulating material 1 of the invention of claim 1 having a predetermined shape.

Invention of Claim 10 is the manufacturing method of the heat insulating material which contains the inorganic raw material 2, the hollow microparticle 3, the reinforcing material, and the thermal deformation suppression material 4, and made the said reinforcing material into the inorganic fiber of laminated structure,
A drying process is performed each time the respective layers of the heat insulating material 1 containing the respective inorganic fibers are sequentially formed.

  In this section, the reference numerals appended to the above terms are not to be construed as limiting the technical scope of the present invention to the section “Example” described later or the contents of the drawings.

  The operational effects of the present invention are as follows.

  The heat insulating material contains an inorganic material, hollow fine particles, a reinforcing material, and a thermal deformation suppressing material. When this heat insulating material is heated, a cured heat insulating material is formed.

  And innumerable cavities are formed inside the heat insulating material by the internal space of the hollow fine particles, and the heat conductivity of the heat insulating material is lowered. For this reason, this heat insulating material improves the heat insulating performance in a high heat atmosphere.

  On the other hand, when innumerable cavities are formed inside the heat insulating material as described above, the strength tends to decrease. However, since the heat insulating material contains the reinforcing material as described above, the strength of the heat insulating material can be improved by the reinforcing material.

  Moreover, according to the said thermal deformation suppression material, the expansion | swelling and shrinkage | contraction of this heat insulating material based on heating the said heat insulating material are suppressed 1stly, and the hardened heat insulating material of the desired shape with more sufficient accuracy is obtained. Can do. Second, when high heat is applied to the cured heat insulating material from the outside, even when the amount of temperature change per unit time in the heat insulating material is large, the heat insulating material is heated by the thermal deformation suppressing material. Expansion and contraction of the heat insulating material based on the above are suppressed. For this reason, it is more reliably prevented that defects such as cracks are generated in the heat insulating material, thereby improving the life.

  That is, as described above, the heat insulating material according to the present invention achieves an improvement in strength and an improvement in life in addition to an improvement in heat insulating performance. For this reason, it can be applied to a heat insulation structure under severe conditions in terms of heat and load, such as furnace walls of various furnaces that are subjected to a large external force or a large thermal shock particularly in a high heat atmosphere.

  Moreover, as described above, since the strength of the heat insulating material is improved, the heat insulating material can be made thinner and lighter accordingly. As a result, it is possible to easily attach the heat insulating materials, and to reduce the required weight of the heat insulating materials as a whole, which is extremely useful in terms of workability and cost.

  The heat insulating material according to the best mode of the present invention contains an inorganic material, hollow fine particles, a reinforcing material, and a thermal deformation suppressing material. In this case, if the clay-like heat insulating material is formed into a desired shape and heated stepwise at 80-200 ° C. and dried, the heat insulating material cured by drying is formed. If the dried heat insulating material is reheated by high heat of 800 ° C. or higher, a further hardened heat insulating material is formed.

  In the above case, if the hollow fine particles are organic, the hollow fine particles are thermally decomposed and disappeared by heating the heat insulating material with the high heat. For this reason, all the heat insulating materials cured by the high heat are inorganic and can withstand a high heat atmosphere. If the hollow fine particles are inorganic, the heat insulating material is originally all inorganic and the heat insulating material can withstand a high heat atmosphere.

  And innumerable cavities are formed inside the heat insulating material by the internal space of the hollow fine particles, and the heat conductivity of the heat insulating material is lowered. For this reason, this heat insulating material improves the heat insulating performance in a high heat atmosphere.

  On the other hand, when innumerable cavities are formed inside the heat insulating material as described above, the strength tends to decrease. However, since the heat insulating material contains the reinforcing material as described above, the strength of the heat insulating material can be improved by the reinforcing material.

  Moreover, according to the said thermal deformation suppression material, the expansion | swelling and shrinkage | contraction of this heat insulating material based on heating the said heat insulating material are suppressed 1stly, and the hardened heat insulating material of the desired shape with more sufficient accuracy is obtained. Can do. Second, when high heat is applied to the cured heat insulating material from the outside, even when the amount of temperature change per unit time in the heat insulating material is large, the heat insulating material is heated by the thermal deformation suppressing material. Expansion and contraction of the heat insulating material based on the above are suppressed. For this reason, it is more reliably prevented that defects such as cracks are generated in the heat insulating material, thereby improving the life.

  Moreover, if the heat insulating material in this form is applied to a specific case, the following effects can be obtained. That is, a compact design by preventing a reduction in the heating efficiency of induction heating, which is a product developed by the inventors described above, and a compact design with a molten metal flow velocity measuring device size are possible, thereby reducing costs. Similarly, when applied to the furnace wall of a conventional induction furnace, the furnace wall can be made thinner and a compact design can be achieved, so that the initial construction cost can be reduced (the same effect can be obtained with a conventional gas furnace). Can do). Moreover, since the space | interval of each heating coil in the said induction heating furnace can be narrowed, a heating efficiency improvement can be aimed at, electric power consumption can be reduced and it can contribute to energy saving.

When the said heat insulating material is demonstrated more concretely, the said inorganic material is an inorganic binder material. As this inorganic material, bentonite, ceramic powder, alkoxyaluminum, zirconia / silica or the like, which is a kind of clay, is used. In this case, it is more preferable to use the bentonite. The main components of this bentonite include silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ), magnesium oxide (MgO) and the like.

If water is mixed into the bentonite and kneaded, it becomes a clay and can be molded into a free shape. Thus, magnesium oxide (MgO) dissolves in water and exhibits alkalinity at the stage where bentonite is made into a clay. For this reason, silicon dioxide (SiO ₂ ) dissolves into a silicate (silanol group: hydroxyl group bonded to silicon). However, in the case of acidity, silicate is not generated. When the silicate is subjected to a heat treatment at 100 to 150 ° C., dehydration and condensation occur, and a clay-like product is generated. And if this clay-like thing is hardened, it will become possible to form a heat insulating material. Bentonite is easy to obtain, is inexpensive, and can easily form a heat insulating material without requiring pretreatment.

  The hollow fine particles are spherical, and the hollow fine particles are generally referred to as balloon materials or microballoons. The material of the hollow fine particles is an organic acrylic resin, epoxy resin, silicon resin or the like. The material of the hollow fine particles 3 may be inorganic.

  Here, when the hollow fine particles are organic, as described above, when the dried heat insulating material is heat-treated with high heat to obtain a cured heat insulating material, the hollow fine particles are thermally decomposed. Disappear.

  For this reason, the capacity | capacitance of the said cavity in the inside of the hardened | cured heat insulating material becomes larger by the part which the said hollow fine particle lose | disappeared, and the heat conductivity of the said heat insulating material further falls. Therefore, the heat insulating performance of this heat insulating material is further improved.

  The hollow fine particles will be described in more detail. When the hollow fine particles are an acrylic resin, the hollow fine particles begin to decompose at about 160 ° C., and then thermally decompose at an elevated temperature and disappear. When the hollow fine particles are epoxy resin or silicon resin, they begin to thermally decompose at about 800 ° C., and then thermally decompose at an elevated temperature and disappear. Thus, when the hollow fine particles are an epoxy resin or the like, the pyrolysis takes time compared to the hollow fine particles being the acrylic resin. On the other hand, when the hollow fine particles contained in the heat insulating material are inorganic materials, they do not disappear even when heated as described above.

  Examples of the organic hollow fine particles include those commercially available as Matsumoto Microsphere (registered trademark). Each particle of the hollow fine particles is organic and includes a resin-made spherical shell and a hydrocarbon sealed inside the shell.

The shell is a polymer and has thermoplasticity, and specifically, an acrylic copolymer, an epoxy resin, a silicon resin, a methacrylate, or a synthetic material thereof is used. The balloon material particles have non-uniform particle diameters and an average particle diameter of 3-110 μm. Moreover, the pressure resistance of this balloon material is 300 kg / cm ² or more, and it has sufficient mechanical strength. For the inorganic hollow fine particles, the shell of each particle may be made inorganic using silica, alumina or the like, or a natural shirasu balloon may be used.

  On the other hand, the form of the hollow fine particles includes an unexpanded form and an already-expanded form obtained by heating and expanding the unexpanded form. Preferably, an already expanded one is used, but an unexpanded one may be used. The reason will be explained. That is, each particle of the unexpanded balloon material has an average particle diameter of 3-45 μm, a shell thickness of 2-15 μm, and a true specific gravity of 0.02-0.05. On the other hand, each particle 5 of the already inflated balloon material 3 is obtained by heating the unexpanded balloon material 3 at 100 ° C. to 200 ° C. to increase the volume by 50 to 100 times. 10-110 micrometers and true specific gravity are 0.02-0.03. Therefore, there is an advantage that one step of the expansion step can be omitted by using the already expanded one, compared with the case of using the unexpanded one.

  However, even the unexpanded one has the following merits. That is, when the unexpanded balloon material is heated to form an already expanded balloon material, this step is performed in water. For this reason, at the end of this step, the already-expanded balloon material contains 85-95% by mass of water to form a wet balloon material. Since this wet balloon material is difficult to fly freely, it can be easily handled thereafter. If this wet balloon material is dried, an already inflated dry balloon material containing 0-5% by weight of water is obtained.

  The already-expanded balloon material may be formed by attaching an inorganic metal salt such as calcium carbonate or an inorganic metal oxide powder such as titanium oxide to the surface of the shell.

  The reinforcing material is contained for the purpose of improving the strength (compressive strength, tensile strength, bending strength) of each part of the heat insulating material, and inorganic fibers are used. This inorganic fiber is a concept including inorganic short fibers and inorganic nonwoven fibers. As a usage form of the reinforcing material, first, when the heat insulating material is formed into a plate shape, the heat insulating material contains both inorganic short fibers and inorganic non-woven fibers. Secondly, when used for a heat insulating material other than a plate, only inorganic short fibers may be contained.

  The inorganic nonwoven fabric fiber used for the plate-shaped heat insulating material is used for the reinforcing layer at the time of lamination, and is mainly contained for the purpose of improving tensile strength and bending strength. As an inorganic short fiber, what cut | disconnected fiber, such as glass and an alumina, about 2-8 mm in length should just be used, and the length of an inorganic short fiber should just be selected according to the size of board thickness. As the inorganic nonwoven fabric fibers, heat resistant materials such as glass fibers, ceramic fibers, and alumina fibers may be used.

  The said heat deformation suppression material suppresses expansion | swelling and shrinkage | contraction of this heat insulating material based on heating a heat insulating material. Although talc is used as the thermal deformation suppressing material, mica may be used. The reason for using talc and mica in this way will be described. That is, talc and mica have a silicate ion structure that spreads in two dimensions, and have a flake shape that does not expand or contract in the direction along the surface even when heated at high temperatures. .

  Talc is a fine powder, hydrophilic, easy to add to water, is inexpensive and can be used as a commercial product without prior treatment. The heat insulating material only needs to contain at least one of talc and mica functionally. And such a thermal deformation suppression material exhibits an excellent effect of thermal shock resistance as well as suppression of expansion and contraction of the thermal insulation material based on heating the thermal insulation material, and partial heat deviation occurs. Even so, damage such as cracks can be prevented like ceramics.

  The mass ratio of the inorganic material / hollow fine particles is preferably 15-2.7. .

  Here, when the mass ratio exceeds 15, the mass% of the inorganic material increases, and the strength of the heat insulating material is improved. However, when the mass% of the hollow fine particles is too small, the amount of the cavities is too small, the thermal conductivity is increased, and the improvement of the heat insulating performance tends to be hindered. On the other hand, when the mass ratio is less than 2.7, the mass% of the inorganic material is decreased and the mass% of the hollow fine particles is excessive, so that the amount of the voids is excessive and the improvement of the strength is inhibited. It tends to be.

  Therefore, as described above, when the mass ratio is 15 to 2.7, the heat insulating performance and strength of the heat insulating material are improved in a well-balanced manner. The mass ratio is more preferably 10-3.0, and still more preferably 6-3.5.

  The mass ratio of the inorganic material / reinforcing material is preferably less than 12-5 because strength improvement by the reinforcing material is required when the thickness of the heat insulating material is 5 mm or less. More preferably, it is 10-7. On the other hand, when the thickness of the heat insulating material exceeds 5 mm, the strength of the heat insulating material itself is improved, and the necessity for improving the strength by the reinforcing material is reduced. More preferably, it is 20.

  Here, when the said mass ratio exceeds each said upper limit, the mass% of an inorganic raw material will become large and the heat insulation performance of a heat insulating material will improve. However, when the mass% of the reinforcing material becomes too small, the strength of the heat insulating material tends to decrease. On the other hand, when the mass ratio is less than the lower limit values, the mass% of the reinforcing material is increased, and the strength of the heat insulating material is improved. However, since the reinforcing material generally has a high thermal conductivity, the heat insulating performance of the heat insulating material tends to be lowered.

  Therefore, as described above, when the mass ratio is within the above ranges, the heat insulating performance and strength of the heat insulating material are improved in a balanced manner.

  The mass ratio of the inorganic material / thermal deformation inhibitor is preferably 0.1-9.

  Here, the talc and mica of the thermal deformation suppressing material do not function as a binder. For this reason, when the mass ratio is less than 0.1, the mass% of the thermal deformation suppressing material becomes large, while the mass% of the inorganic material becomes too small, and the improvement of the strength of the heat insulating material is hindered. On the other hand, if the mass ratio exceeds 9, the mass% of the inorganic material increases, but the mass% of the thermal deformation suppressing material becomes too small, and the expansion and contraction of the heat insulating material based on heating the heat insulating material is suppressed. It becomes difficult to do.

  Thus, as described above, when the mass ratio is 0.1-9, the heat insulating material can improve the strength and more reliably prevent the occurrence of defects such as cracks. The mass ratio is more preferably 0.1-2.0, and still more preferably 0.1-1.0.

  A method for producing the single plate-shaped heat insulating materials 1, 9, 17, and 20 containing the unexpanded hollow fine particles 3 will be described with reference to FIGS.

  First, as a first step (kneading / expansion step), water is added to the inorganic material 2, the hollow fine particles 3 of the unexpanded product, the reinforcing material, and the thermal deformation suppressing material 4, and batch type or continuous extrusion type Kneading with a mixer or the like. The hollow fine particle 3 includes an organic spherical shell 6 and a hydrocarbon 7 sealed inside the shell 6. And the clay-like heat insulating material 1 is shape | molded by the said kneading | mixing. This heat insulating material 1 can be the final product 8. Next, the said heat insulating material 1 is accommodated in an airtight pressure vessel (not shown), and is heated at 100-200 degreeC. Then, each said hollow microparticle 3 in the heat insulating material 1 expand | swells, respectively, and after cooling, the clay-like secondary heat insulating material 9 which can be shape | molded to a free shape is shape | molded.

  Next, as a second step (molding step), a primary intermediate molded product 10 such as a block is molded by the molding machine using the secondary heat insulating material 9. Further, the primary intermediate molded product 10 may be molded like a tile, a brick, or a wall unit.

  Next, as a third step (preparation step), in the state where the primary intermediate molded product 10 is sealed in the sealed mold 13, the intermediate molded product 10 is removed by a jack while venting air in the sealed mold 13. Surface pressure is applied to Then, the intermediate molded product 14 having a uniform film thickness is formed.

  Next, as the fourth step (drying step), the secondary intermediate molded product 14 is taken out from the sealed mold 13. And this intermediate molded product 14 is heated for about 30 minutes to about 80 degreeC with the drying furnace 16 as primary drying. Further, the secondary intermediate molded product 14 is dried in a drying furnace 16 at 100 ° C. or higher for 1 hour or more as secondary drying. Thus, the tertiary heat insulating material 17 which is cured by being heated stepwise and dried and completely dehydrated and condensed is formed. This heat insulating material 17 has sufficient strength and rigidity.

  Here, as described above, the reason why the secondary intermediate molded product 14 is once heated to 80 ° C. is as follows. That is, in general, the intermediate molded product 14 contains extra water in addition to the bonding water necessary for forming the heat insulating material 17. For this reason, if the intermediate molded product 14 is heated to 100 ° C. or more at once, the above-described excess moisture may bump and cause a crack in the heat insulating material. Therefore, in order to prevent this, drying is performed by heating stepwise as described above. In addition, even if the said secondary intermediate molded product 14 is dried at 80 degreeC, when the said crack arises, in order to prevent generation | occurrence | production of this crack, you may make it as follows. That is, the drying may be natural drying. In addition, cellulose may be mixed in the secondary intermediate molded product 14 in advance and dried while suppressing water evaporation.

  Next, as the fifth step (firing step), the tertiary heat insulating material 17 is heated to 800 ° C. or higher by the heating furnace 19 to form the heat insulating material 20. During the heating, the hollow fine particles 3 disappear due to thermal decomposition. For this reason, countless cavities 22 are formed inside the heat insulating material 20. Moreover, when the material of the said inorganic short fiber and inorganic nonwoven fabric fiber fuse | melts in the said heating, and melt | dissolves in the structure | tissue of the said heat insulating material 17, it functions as a binder and the intensity | strength of the heat insulating material 20 shape | molded is raised.

  In addition to the heat insulating material 1, the secondary heat insulating material 9, the tertiary heat insulating material 17, and the fourth heat insulating material 20 formed in each of the process steps may be used as the final product 8.

  When the secondary heat insulating material 9 is used as the final product 8, the secondary heat insulating material 9 is attached along the metal outer wall plate 21 of the furnace wall of the heating furnace, for example. In this case, as in the second step, the intermediate molded product 10 may be formed by the secondary heat insulating material 9, and the process may proceed to the third step. On the other hand, the process may proceed to the fourth process without passing through the second and third processes. In the fourth step, the secondary heat insulating material 9 or the intermediate molded product 10 of the furnace wall is dried to form the tertiary heat insulating material 17.

  Next, the manufacturing method of the single plate-shaped heat insulating material containing the hollow fine particles 3 of the already expanded product will be described.

  In the above method, the manufacturing process using the hollow microparticles 3 of the unexpanded product and the second, third, fourth, and fifth processes are the same, but the hollow microparticles 3 of the already expanded product are used. It is possible to omit the expansion process.

  However, when the secondary heat insulating material 9 is used as the final product 8, the secondary heat insulating material 9 is extended along the metal outer wall plate 21 of the furnace wall of the heating furnace, for example, as shown in FIG. . In this case, the intermediate molded product 10 may be formed by the secondary heat insulating material 9 as in the second step, and the process may proceed to the third step. On the other hand, the process may proceed to the fourth process without passing through the second and third processes.

  In the fourth step, the secondary heat insulating material 9 or the intermediate molded product 10 of the furnace wall is dried to form the tertiary heat insulating material 17. Next, as in the fifth step, the third heat insulating material 17 is heated by the heat of the furnace to form the fourth heat insulating material 20, thereby forming a heat resistant furnace wall.

  Next, the manufacturing method of the laminated board-shaped heat insulating material using the hollow fine particles 3 of the already expanded product will be described.

  In FIG. 2, the intermediate molded product 10 includes a plurality (three layers) of heat insulating material layers 11 formed by the secondary heat insulating material 9 and a plurality (two layers) interposed between the heat insulating material layers 11. These reinforcing layers 12 are integrally fixed to each other. Of the inorganic fibers, the reinforcing layer 12 is particularly made of inorganic nonwoven fibers, but inorganic short fibers may also be used.

  When forming the heat insulating material layer 11 having the above three-layer structure, the manufacturing process using the hollow microparticles 3 of the above-described already expanded product is the same as the first, second, and fifth processes, and is laminated and dried in the third and fourth processes. I do. As a third step, a release paper is laid on the sealing mold 13 with the lid removed, a first heat insulating material layer 11 is formed on the upper surface of the release paper, and a first reinforcing layer 12 is formed on the upper surface. Then, a second heat insulating material layer 11 is formed on the upper surface, and a two-layer molded product is formed.

  Then, another release paper is laid on the upper surface of the two-layer molded product, the sealing mold 13 is covered from above, and surface pressure is applied with a jack while venting air to make the film thickness of the two-layer molded product uniform. To. Next, as a fourth step, the two-layer molded product is taken out from the sealed mold 13, the release papers are peeled off, and dried in a drying furnace at 80 ° C. for about 30 minutes. Is molded.

  In this state, the heat insulating material layer 11 has two layers and the reinforcing layer 12 has one layer. Therefore, in order to form another heat insulating material layer 11 and reinforcing layer 12, the third step is performed again. That is, release paper is laid again on the sealing mold 13 and the two-layer molded product is turned inside out. Next, the second reinforcing layer 12 is placed on the upper surface, and the remaining heat insulating material layer 11 is formed thereon. Next, release paper is placed on the upper surface, a lid is applied from above, and surface pressure is applied with a jack while venting air. Then, a three-layer molded product is molded. Next, the three-layer molded product is taken out from the sealed mold 13 and again dried at 80 ° C. for about 30 minutes in the drying furnace 16 as a fourth step. In this way, a three-layer molded article is formed by the three heat insulating material layers 11 and the two reinforcing layers 12 as shown in FIG.

  Although the description here is about the three-layer molded article, it is not limited to the number of layers, and the number of layers can be increased or decreased according to the required strength. Similarly, the formation of four or more heat insulating material layers 11 may be performed by repeating the third step and the fourth step every time one layer is added.

  In the case where the above-described reinforcing layer 12 made of inorganic fibers is a heat insulating material having two or more layers, it is located on the outer side (at least one of the front layer and the back layer) than the two outermost reinforcing layers 12 and 12. The average particle diameter of the hollow fine particles of the heat insulating material layer 11 is 40-5 μm. In this way, even when the heat insulating performance is improved by increasing the average particle diameter of the hollow fine particles of the heat insulating material layer 11 between the two reinforcing layers 12, 12, the outer surface of the heat insulating material is improved. The roughness can be made fine and the finished surface can be made beautiful. The average particle diameter of the hollow fine particles 3 is more preferably 30-10 μm.

  Hereinafter, each Example is shown as Example 1-3, and the specific contents are shown in [Table 1] below.

  In this embodiment, a heat insulating material having a three-layer structure as shown in FIG. 2 and a thickness dimension A = 5 mm is formed through each step. Example 1 corresponds to Experiments NO1-NO4 in the above [Table 1]. These experiments were performed only on the spherical hollow fine particles while changing the content thereof, and the respective effects were confirmed.

(Insulation material)
Inorganic material: Bentonite 15g
Spherical hollow fine particles: 3-6 g of microballoons
(Made by Matsumoto Yushi Seiyaku Co., Ltd., trademark Matsumoto Microsphere,
F-80ED, particle size 90-110μm)
Thermal deformation inhibitor: Talc 15g
Inorganic short fiber: 1.25 g of glass short fiber (length: 3 mm)
Inorganic nonwoven fiber: 1.42 g of glass fiber
(150 x 150 mm x 2 sheets)
Water: 70g of pure water
Prepared.

(Production method)
Since all the procedures are the same, first, as a representative example, a procedure related to the first embodiment will be described.

  As a 1st process, the said glass short fiber and water are put into a beaker, and it mounts on a magnetic stirrer, and stirring by this stirrer is performed for about 10 minutes.

  Next, a part of the bendnite / talc mixture was gradually added to the beaker while stirring. Next, the agitation was released, the microbeon was added from the beaker to a 3 l (liter) container, and agitated with a stir bar. Further, the remaining portion of the mixture of bendnite and talc was gradually added to the above 3 l (liter) container, and stirred with a stir bar to form a clay-like preparation.

  Next, as a second step, three heat-insulated molded articles were prepared.

  Next, as a third step, a release paper is installed in a closed mold, and a first heat-insulating material layer is formed on the upper surface of the release paper, and a reinforcing layer is formed on the upper surface. The first layer of glass fiber was placed, and the second molded product was placed on the upper surface thereof to form a second heat insulating material layer, and a two-layer molded product was molded.

  Then, another release paper is laid on the upper surface of the primary intermediate molded product, a sealed mold is covered from above, and surface pressure is applied with a jack while venting air to make the film thickness of the two-layer molded product uniform. did.

  Next, as a fourth step, the two-layer molded product is taken out from the sealed mold, and each release paper is peeled off, and dried in a drying furnace at 80 ° C. for 30 minutes to form a tertiary heat insulating material. . In this state, there are two heat insulating material layers and one reinforcing layer. Therefore, the third step is performed again in order to form another heat insulating material layer and a reinforcing layer. That is, release paper is laid again on the sealed mold, and the two-layer molded product is turned upside down. Next, a second-layer glass fiber is placed on the upper surface, and a third molded product is placed thereon. Next, release paper is placed on the upper surface, a lid is applied from above, and surface pressure is applied with a jack while venting air. Then, a three-layer molded product is molded. Next, the three-layer molded product was taken out from the sealed mold.

  Again, as a 4th process, it dried at 80 degreeC for 30 minutes with the said drying furnace, and shape | molded the tertiary heat insulating material. Next, as a fifth step, the heat insulating material of the target experiment NO1 was formed by heating to 1100 ° C. in a heating furnace.

(result)
It can be understood that the thermal conductivity (W / m · K) decreases as the amount of microballoons increases. Further, it was found that the strength test result was 2.5 in terms of the evaluation value (1) ÷ (2) [inorganic material (g) ÷ spherical hollow fine particles (g)] of 2.5. 7 or more is preferable, and 3.0 or more is more preferable.

  Regarding the heat insulating material this time, the heat-resistant temperature is about 1100 ° C., the heat resistance of the heat-resistant castable, which is about 1100 ° C., which is equivalent to the heat-resistant temperature in the prior art, and from 800 ° C. to 300 ° C. Comparing the thickness (mm) of the heat insulating material necessary for heat insulation at about 0 ° C., it can be understood that it is low in each stage.

(Insulation material of this time) Insulation brick Castable refractory thermal conductivity (W / m · K) 0.065 or less ≒ 0.12 ≒ 0.25
Thickness (mm) 5mm or less ≒ 10mm ≒ 19mm

  In this example as well, as in Example 1, a heat insulating material having a three-layer structure as shown in FIG. Example 2 corresponds to Experiments NO5-NO7 in [Table 1]. These experiments were carried out by changing the contents of only the inorganic material and the thermal deformation suppressing material, and the respective effects were confirmed.

(Insulation material)
Inorganic material: bentonite 3-27g
Spherical hollow fine particles: 3g microballoon
(Matsumoto Yushi Seiyaku Co., Ltd., trademark Matsumoto Microsphere F-80ED, particle size 90-110 μm)
Thermal deformation inhibitor: talc 3-27g
Inorganic short fiber: 1.25 g of glass short fiber (length: 3 mm)
Inorganic nonwoven fiber: 1.42 g of glass fiber
(150 x 150 mm x 2 sheets)
Water: 70g of pure water
Prepared.

(Production method)
Since it is the same as that of Example 1, it abbreviate | omits.

(result)
It can be understood that the higher the content of the thermal deformation inhibitor, the lower the shrinkage rate. Practically, the evaluation value (1) ÷ (3) [inorganic material (g) ÷ heat deformation suppressing material (g)] is preferably 0.1-9, and preferably 0.1-2.0. More preferably, it is still more preferably 0.1-1.0.

  In this example as well, as in Example 1, a heat insulating material having a three-layer structure as shown in FIG. Example 3 corresponds to Experiments NO8-NO11 in [Table 1]. These experiments were performed only on inorganic fibers by changing their contents, and the respective effects were confirmed.

(Insulation material)
Inorganic material: Bentonite 15g
Spherical hollow fine particles: 3g microballoon
(Matsumoto Yushi Seiyaku Co., Ltd., trademark Matsumoto Microsphere F-80ED, particle size 90-110 μm)
Thermal deformation inhibitor: Talc 15g
Inorganic short fibers: Presence / absence of 1.25 g of glass short fibers (length: 3 mm) Inorganic non-woven fiber: Presence / absence of 1.42 g of glass fibers
(150 x 150 mm x 2 sheets)
Water: 70g of pure water
Prepared.

(Production method)
Since it is the same as that of Example 1, it abbreviate | omits.

(result)
As an effect of the reinforcing material, an improvement in strength was observed in the tensile test by employing inorganic short fibers and inorganic nonwoven fibers, which are inorganic fibers. Moreover, although the bending test was not done, Experiment NO8 and Experiment NO11 were confirmed by hand sense. As a result, in Experiment NO8, if any surface cracks are generated, they are easily broken. However, since experiment NO11 maintains the plate shape even if surface cracks are slightly generated, it seems that an effect more than the effect in the tensile test has occurred.

It is a figure which shows the flow at the time of drying and heating a heat insulating material and shape | molding another heat insulating material. It is a fragmentary perspective sectional view of an intermediate molded product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat insulating material 2 Inorganic material 3 Hollow fine particle 4 Thermal deformation suppression material 5 Reinforcement material 8 Final product 9 Secondary heat insulating material 10 Primary intermediate molded product 13 Sealed mold 14 Secondary intermediate molded product 16 Drying furnace 17 Tertiary heat insulating material 19 Heating Furnace 20 Fourth heat insulating material 22 Cavity

Claims (10)

  A heat insulating material comprising an inorganic material, hollow fine particles, a reinforcing material, and a thermal deformation suppressing material.   The heat insulating material according to claim 1, wherein the inorganic material is bentonite.   The heat insulating material according to claim 1, wherein the hollow fine particles are organic.   The heat insulating material according to claim 1, wherein the thermal deformation suppressing material is at least one of talc and mica.   The heat insulating material according to claim 1, wherein the reinforcing material is an inorganic fiber.   6. The heat insulating material according to claim 5, wherein the inorganic fiber has a laminated structure.   The heat insulating material according to claim 1, wherein a mass ratio of the inorganic material / thermal deformation suppressing material is 0.1-9.   7. The heat insulating material according to claim 6, wherein the inorganic fiber has a structure of two or more layers, and the average particle diameter of the hollow fine particles positioned outside the two outermost inorganic fibers is 40-5 [mu] m.   The heat insulating material according to claim 1, wherein the heat insulating material has a predetermined shape and is formed by heating the heat insulating material. A method for producing a heat insulating material comprising an inorganic material, hollow fine particles, a reinforcing material, and a thermal deformation suppressing material, wherein the reinforcing material is an inorganic fiber having a laminated structure,
A method for producing a heat insulating material, wherein a drying treatment is performed each time the layers of the heat insulating material containing the respective inorganic fibers are sequentially formed.

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